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Sample records for iii metal liner

  1. The use of volcanic soil as mineral landfill liner--III. Heavy metals retention capacity.

    PubMed

    Navia, Rodrigo; Fuentes, Bárbara; Diez, María C; Lorber, Karl E

    2005-06-01

    The volcanic soil of Southern Chile was tested for its heavy metal retention capacity. The maximum uptakes for CrO4(2-) (CrVI), Cu(2+), Zn(2+) and Pb(2+) were determined to be 2.74, 5.32, 5.86 and 7.44 mg g(-1), respectively. At a slightly alkaline pH value (7.5), it seems that a precipitation-adsorption process was responsible for the Cu(2+) and Zn(2+) uptake onto volcanic soil. All the determined values are of the same order of magnitude as natural zeolites heavy metals adsorption capacities. In addition, the heavy metals diffusion model through a 1 m volcanic soil mineral liner shows breakthrough times of 21.6, 10.2 and 8.9 years, for Pb(2+), Zn(2+) and Cu(2+), respectively, confirming the trend obtained in the adsorption isotherms. The natural volcanic soil of Southern Chile is an interesting material for possible use as landfill mineral basal sealing. It has an appropriate sealing potential (average Kf value of 5.85 x 10(-9) m s(-1)) and a heavy metals retention capacity comparable with natural zeolites. About two-thirds of the agricultural land in Chile (approximately 0.4 million km2) is derived from volcanic ash, suggesting an important soil volume for future landfill projects, that could be obtained in sufficient quantities from urban building activities.

  2. Surface treatment using metal foil liner

    NASA Technical Reports Server (NTRS)

    Garvey, Ray

    1989-01-01

    A metal foil liner can be used to seal large area surfaces. Characteristics of the two-layer foil liner are discussed. Micrographs for foil-to-foil, foil-to-composite, visible seams, and hidden seams are examined.

  3. Expandable Metal Liner For Downhole Components

    DOEpatents

    Hall, David R.; Fox, Joe R.

    2004-10-05

    A liner for an annular downhole component is comprised of an expandable metal tube having indentations along its surface. The indentations are formed in the wall of the tube either by drawing the tube through a die, by hydroforming, by stamping, or roll forming and may extend axially, radially, or spirally along its wall. The indentations accommodate radial and axial expansion of the tube within the downhole component. The tube is inserted into the annular component and deformed to match an inside surface of the component. The tube may be expanded using a hydroforming process or by drawing a mandrel through the tube. The tube may be expanded in such a manner so as to place it in compression against the inside wall of the component. The tube is useful for improving component hydraulics, shielding components from contamination, inhibiting corrosion, and preventing wear to the downhole component during use. It may also be useful for positioning conduit and insulated conductors within the component. An insulating material may be disposed between the tube and the component in order to prevent galvanic corrosion of the downhole component.

  4. Cementation of a polyethylene liner into a metal acetabular shell: a biomechanical study.

    PubMed

    Hofmann, Aaron A; Prince, Edward J; Drake, F Thurston; Hunt, Kenneth J

    2009-08-01

    Cementation of a liner into a well-fixed acetabular shell is common in revision hip arthroplasty. We compare the biomechanical strengths of cemented liners with standard locked liners. Fifty polyethylene liners were inserted into acetabular shells using the standard locking mechanism or 1 of 2 cement types then loaded to failure by torsion or lever-out testing. Lever-out testing showed that all cemented liners failed at similar loads to standard locked liners. With torsion testing, cemented liners failed at significantly higher loads than standard locked liners; roughening the liner increased load to failure. Cementation of an acetabular liner into a metal shell is safe and strong and a good alternative to metal shell replacement. Saw roughening of the polyethylene liner strengthens the poly-cement interface.

  5. Metal liner-driven quasi-isentropic compression of deuterium

    SciTech Connect

    Weinwurm, Marcus; Bland, Simon N.; Chittenden, Jeremy P.

    2013-09-15

    Properties of degenerate hydrogen and deuterium (D) at pressures of the order of terapascals are of key interest to Planetary Science and Inertial Confinement Fusion. In order to recreate these conditions in the laboratory, we present a scheme, where a metal liner drives a cylindrically convergent quasi-isentropic compression in a D fill. We first determined an external pressure history for driving a self-similar implosion of a D shell from a fictitious flow simulation [D. S. Clark and M. Tabak, Nucl. Fusion 47, 1147 (2007)]. Then, it is shown that this D implosion can be recreated inside a beryllium liner by shaping the current pulse. For a peak current of 10.8 MA cold and nearly isochoric D is assembled at around 12 500 kg/m{sup 3}. Finally, our two-dimensional Gorgon simulations show the robustness of the implosion method to the magneto-Rayleigh-Taylor instability when using a sufficiently thick liner.

  6. Heat dissipating nuclear reactor with metal liner

    DOEpatents

    Gluekler, E.L.; Hunsbedt, A.; Lazarus, J.D.

    1985-11-21

    A nuclear reactor containment including a reactor vessel disposed within a cavity with capability for complete inherent decay heat removal in the earth and surrounded by a cast steel containment member which surrounds the vessel is described in this disclosure. The member has a thick basemat in contact with metal pilings. The basemat rests on a bed of porous particulate material, into which water is fed to produce steam which is vented to the atmosphere. There is a gap between the reactor vessel and the steel containment member. The containment member holds any sodium or core debris escaping from the reactor vessel if the core melts and breaches the vessel.

  7. Heat dissipating nuclear reactor with metal liner

    DOEpatents

    Gluekler, Emil L.; Hunsbedt, Anstein; Lazarus, Jonathan D.

    1987-01-01

    Disclosed is a nuclear reactor containment including a reactor vessel disposed within a cavity with capability for complete inherent decay heat removal in the earth and surrounded by a cast steel containment member which surrounds the vessel. The member has a thick basemat in contact with metal pilings. The basemat rests on a bed of porous particulate material, into which water is fed to produce steam which is vented to the atmosphere. There is a gap between the reactor vessel and the steel containment member. The containment member holds any sodium or core debris escaping from the reactor vessel if the core melts and breaches the vessel.

  8. Mechanical failure of metal-polyethylene sandwich liner in metal-on-metal total hip replacement.

    PubMed

    Oshima, Yasushi; Fetto, Joseph F

    2015-01-01

    Metal-on-metal had been proposed as an optimal articulation in THRs, however, many monoblock prostheses have been recalled in the USA because of significant high rates of early failure. Metal-on-metal prostheses had been implanted in our institution, and this is a case history of a single patient, in whom metal-on-metal THRs with different femoral sizes of heads were implanted. A 57-year-old female patient underwent bilateral total hip replacements with metal-on-metal prostheses using metal-polyethylene "sandwich" liners 9 years ago on the right side and 7 years ago on the left side respectively. The only difference in both sides was the femoral head diameter of 28 mm in right and 34 mm in left. Seven years after the left surgery, the acetabular liner was dissociated, however, metallosis was not detected. Although the larger femoral head was thought to increase hip joint stability, it dictated a reduction in polyethylene thickness in this prosthesis design, and it was 4 mm in the left hip. Recently, metal-on-metal articulations are thought not to be optimal for hip joint bearing surface, however, this clinical failure was due to the polyethylene thickness and quality.

  9. Small gas turbine combustor experimental study - Compliant metal/ceramic liner and performance evaluation

    NASA Technical Reports Server (NTRS)

    Acosta, W. A.; Norgren, C. T.

    1986-01-01

    Combustor research relating to the development of fuel efficient small gas turbine engines capable of meeting future commercial and military aviation needs is currently underway at NASA Lewis. As part of this combustor research, a basic reverse-flow combustor has been used to investigate advanced liner wall cooling techniques. Liner temperature, performance, and exhaust emissions of the experimental combustor utilizing compliant metal/ceramic liners were determined and compared with three previously reported combustors that featured: (1)splash film-cooled liner walls; (2) transpiration cooled liner walls; and (3) counter-flow film cooled panels.

  10. Small gas turbine combustor experimental study: Compliant metal/ceramic liner and performance evaluation

    NASA Technical Reports Server (NTRS)

    Acosta, W. A.; Norgren, C. T.

    1986-01-01

    Combustor research relating to the development of fuel efficient small gas turbine engines capable of meeting future commercial and military aviation needs is currently underway at NASA Lewis. As part of this combustor research, a basic reverse-flow combustor has been used to investigate advanced liner wall cooling techniques. Liner temperature, performance, and exhaust emissions of the experimental combustor utilizing compliant metal/ceramic liners were determined and compared with three previously reported combustors that featured: (1) splash film-cooled liner walls; (2) transpiration cooled liner walls; and (3) counter-flow film cooled panels.

  11. Low-Speed Fan Noise Attenuation from a Foam-Metal Liner

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.; Jones, Michael G.

    2011-01-01

    A foam-metal liner for attenuation of fan noise was developed for and tested on a low-speed fan. This type of liner represents a significant advance over traditional liners, due to the possibility of placement in close proximity to the rotor. An advantage of placing treatment in this region is that the acoustic near field is modified, thereby inhibiting the noise-generation mechanism. This can result in higher attenuation levels than could be achieved by liners located in the nacelle inlet. In addition, foam-metal liners could potentially replace the fan rub strip and containment components, ultimately reducing engine components and thus weight, which can result in a systematic increase in noise reduction and engine performance. Foam-metal liners have the potential to reduce fan noise by 4 dB based on this study.

  12. Foam-Metal Liner Attenuation of Low-Speed Fan Noise

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.; Jones, Michael G.

    2008-01-01

    A foam-metal liner for attenuation of fan noise was developed for and tested on a low speed fan. This type of liner represents a significant advance over traditional liners due to the possibility for placement in close proximity to the rotor. An advantage of placing treatment in this region is the modification of the acoustic near field, thereby inhibiting noise generation mechanisms. This can result in higher attenuation levels than can be achieved by liners located in the nacelle inlet. In addition, foam-metal liners could potentially replace the fan rub-strip and containment components, ultimately reducing engine components and thus weight, which can result in a systematic increase in noise reduction and engine performance. Foam-metal liners have the potential to reduce fan noise by 4 dB based on this study.

  13. Ceramic coating effect on liner metal temperatures of film-cooled annular combustor

    NASA Technical Reports Server (NTRS)

    Claus, R. W.; Wear, J. D.; Liebert, C. H.

    1979-01-01

    An experimental and analytical investigation was conducted to determine the effect of a ceramic coating on the average metal temperatures of full annular, film cooled combustion chamber liner. The investigation was conducted at pressures from 0.50 to 0.062. At all test conditions, experimental results indicate that application of a ceramic coating will result in significantly lower wall temperatures. In a simplified heat transfer analysis, agreement between experimental and calculated liner temperatures was achieved. Simulated spalling of a small portion of the ceramic coating resulted in only small increases in liner temperature because of the thermal conduction of heat from the hotter, uncoated liner metal.

  14. Metal neck and liner impingement in ceramic bearing total hip arthroplasty.

    PubMed

    Lee, Young-Kyun; Yoo, Jeong Joon; Koo, Kyung-Hoi; Yoon, Kang Sup; Kim, Hee Joong

    2011-02-01

    Although impingement between the neck of the metallic stem and the ceramic liner has been suspected to be the cause of ceramic liner failure in ceramic-on-ceramic total hip arthroplasty (THA), no report has directly demonstrated microscopic damage on ceramic liner. We performed 18 reoperations on 18 patients who had undergone third generation ceramic-on-ceramic THA. Considering impingement, 16 patients, who were reoperated more than 1 year after previous ceramic bearing THA, were evaluated. Retrieved alumina liners, showing evidence of impingement, were examined by means of visual inspection and scanning electron microscopy (SEM). Four of the 16 hips showed neck notching and black stained liners, evidence of metallic neck to ceramic impingement. Impinged alumina bearings had been implanted for an average of 62.5 months (range: 35-99 months) before reoperation. SEM of the black stained area demonstrated disruptive wear and loss of surface integrity. Furthermore, one liner had multiple microcracks, and its cross-sectional SEM analysis revealed one microcrack propagating into the deep portion of the ceramic liner. Our observations suggest that metal neck-to-ceramic impingement in ceramic-on-ceramic THA can cause microcrack formation in ceramic liner. Copyright © 2010 Orthopaedic Research Society.

  15. Corrosion on the acetabular liner taper from retrieved modular metal-on-metal total hip replacements.

    PubMed

    Gascoyne, Trevor C; Dyrkacz, Richard M; Turgeon, Thomas R; Burnell, Colin D; Wyss, Urs P; Brandt, Jan-M

    2014-10-01

    Eight retrieved metal-on-metal total hip replacements displayed corrosion damage along the cobalt-chromium alloy liner taper junction with the Ti alloy acetabular shell. Scanning electron microscopy indicated the primary mechanism of corrosion to be grain boundary and associated crevice corrosion, which was likely accelerated through mechanical micromotion and galvanic corrosion resulting from dissimilar alloys. Coordinate measurements revealed up to 4.3mm(3) of the cobalt-chromium alloy taper surface was removed due to corrosion, which is comparable to previous reports of corrosion damage on head-neck tapers. The acetabular liner-shell taper appears to be an additional source of metal corrosion products in modular total hip replacements. Patients with these prostheses should be closely monitored for signs of adverse reaction towards corrosion by-products.

  16. Fretting and Corrosion Between a Metal Shell and Metal Liner May Explain the High Rate of Failure of R3 Modular Metal-on-Metal Hips.

    PubMed

    Ilo, Kevin C; Derby, Emma J; Whittaker, Robert K; Blunn, Gordon W; Skinner, John A; Hart, Alister J

    2017-05-01

    The R3 acetabular system used with its metal liner has higher revision rates when compared to its ceramic and polyethylene liner. In June 2012, the medical and healthcare products regulatory agency issued an alert regarding the metal liner of the R3 acetabular system. Six retrieved R3 acetabular systems with metal liners underwent detailed visual analysis using macroscopic and microscopic techniques. Visual analysis discovered corrosion on the backside of the metal liners. There was a distinct border to the areas of corrosion that conformed to antirotation tab insertions on the inner surface of the acetabular shell, which are for the polyethylene liner. Scanning electron microscopy indicated evidence of crevice corrosion, and energy-dispersive X-ray analysis confirmed corrosion debris rich in titanium. The high failure rate of the metal liner option of the R3 acetabular system may be attributed to corrosion on the backside of the liner which appear to result from geometry and design characteristics of the acetabular shell. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Formation of metal and dielectric liners using a solution process for deep trench capacitors.

    PubMed

    Ham, Yong-Hyun; Kim, Dong-Pyo; Baek, Kyu-Ha; Park, Kun-Sik; Kim, Moonkeun; Kwon, Kwang-Ho; Shin, Hong-Sik; Lee, Kijun; Do, Lee-Mi

    2012-07-01

    We demonstrated the feasibility of metal and dielectric liners using a solution process for deep trench capacitor application. The deep Si trench via with size of 10.3 microm and depth of 71 microm were fabricated by Bosch process in deep reactive ion etch (DRIE) system. The aspect ratio was about 7. Then, nano-Ag ink and poly(4-vinylphenol) (PVPh) were used to form metal and dielectric liners, respectively. The thicknesses of the Ag and PVPh liners were about 144 and 830 nm, respectively. When the curing temperature of Ag film increased from 120 to 150 degrees C, the sheet resistance decreased rapidly from 2.47 to 0.72 Omega/sq and then slightly decreased to 0.6 Omega/sq with further increasing the curing temperature beyond 150 degrees C. The proposed liner formation method using solution process is a simple and cost effective process for the high capacity of deep trench capacitor.

  18. Effect of Inner Taper Angle of Acetabular Metal Shell on the Malseating and Dissociation Force of Ceramic Liner.

    PubMed

    Lee, Young-Kyun; Kim, Ki-Chul; Jo, Woo-Lam; Ha, Yong-Chan; Parvizi, Javad; Koo, Kyung-Hoi

    2017-04-01

    Malseating of ceramic liner appeared as a matter of concern in multibearing metal, although multibearing cup can be coupled with hard liners as well as polyethylene liner. In this metal shell, the inner taper angle should be 10° for the modularity, while standard metal shells for ceramic liner have an inner taper angle of 18°. However, there has been no study in the effect of taper angle to the risk of malseating. We evaluated whether the taper angle of metal shell might affect the malseating of ceramic liner, and dissociation force of ceramic liner from metal shell. Three surgeons manually inserted ceramic liners into two designs of metal shell with different tapers angles (10° and 18°). We compared malseating rates of ceramic liners and push-out strengths, which means dissociation force of the ceramic liner from the metal shell, between these two metal shell designs. The malseating rates in 10° metal shell were higher than those in 18° metal shell (23.3% vs 0%, P < .05). The mean dissociation force (1148.8 ± 46.7 N) in 10° taper cup was higher than that (389.7 ± 108.3 N) in 18° taper cup (P < .01). Our results suggest that surgeon should be cautious about malseating of ceramic liner when using multi-bearing metal shell with inner taper angle of 10°. When surgeon use multi-bearing metal shell with inner taper angle of 10°, our results suggest that surgeon should be cautious about malseating of ceramic liner. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Autofrettage to Counteract Coefficient of Thermal Expansion Mismatch in Cryogenic Pressurized Pipes with Metallic Liners

    NASA Technical Reports Server (NTRS)

    Wen, Ed; Barbero, Ever; Tygielski, Phlip; Turner, James E. (Technical Monitor)

    2001-01-01

    Composite feedlines with metal liners have the potential to reduce weight/cost while providing the same level of permeation resistance and material compatibility of all-metal feedlines carrying cryogenic propellants in spacecraft. The major technical challenges are the large difference in Coefficient of Thermal Expansion between the liner and the composite, and the manufacturing method required to make a very thin liner with the required strength and dimensional tolerance. This study investigates the use of autofrettage (compressive preload) to counteract Coefficient of Thermal Expansion when pre-pressurization procedures cannot be used to solve this problem. Promising materials (aluminum 2219, Inconel 718, nickel, nickel alloy) and manufacturing techniques (chemical milling, electroplating) are evaluated to determine the best liner candidates. Robust, autofrettaged feedlines with a low Coefficient of Thermal Expansion liner (Inconel 718 or nickel alloy) are shown to successfully counteract mismatch at LOX temperature. A new concept, autofrettage by temperature, is introduced for high Coefficient of Thermal Expansion materials (aluminum and pure nickel) where pressure cannot be used to add compressive preload.

  20. Early failure of a polyethylene acetabular liner cemented into a metal cup.

    PubMed

    Wilson, David A J; Corkum, Joseph P; Teeter, Matthew G; Holdsworth, David W; Dunbar, Michael J

    2012-05-01

    In 2002, a patient underwent revision total hip arthroplasty for polyethylene wear. The acetabular cup was well fixed, and it was decided to cement a new polyethylene liner into the existing cup. In 2006, the patient presented with inability to weight bear and easy subluxation of the hip. Revision surgery was performed, and all components were examined postoperatively. Investigation with microcomputed tomography revealed that the liner had plastically deformed at the superior pole resulting in the hip instability. The reasons for this are suspected to be related to the abducted nature of the original cup and an uneven cement mantle. This report suggests that cementation of polyethylene liners into metal cups has limitations and is not appropriate in all circumstances. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Is There a Difference in Revision Risk Between Metal and Ceramic Heads on Highly Crosslinked Polyethylene Liners?

    PubMed

    Cafri, Guy; Paxton, Elizabeth W; Love, Rebecca; Bini, Stefano A; Kurtz, Steven M

    2017-05-01

    = 0.025). For dislocation, ceramic heads increased risk relative to metal at < 32 mm only (HR = 4.39 [1.72-11.19], p = 0.002, adjusted p = 0.020). Head sizes < 32 mm were associated with increased risk of dislocation relative to 36 mm for metal (HR = 2.99 [1.40-6.39], p = 0.005, adjusted p = 0.047) and ceramic heads (HR = 15.69 [6.07-40.55], p < 0.001, adjusted p < 0.001). The results did not provide evidence for use of one femoral head material over another when used with HXLPE liners for the outcome of revision, but for dislocation, metal performed better than ceramic with < 32-mm heads. Overall, the findings suggest increased risk of revision/dislocation with head sizes < 32 mm. Level III, therapeutic study.

  2. Investigation of Spheromak Plasma Cooling through Metallic Liner Spallation during Compression

    NASA Astrophysics Data System (ADS)

    Ross, Keeton; Mossman, Alex; Young, William; Ivanov, Russ; O'Shea, Peter; Howard, Stephen

    2016-10-01

    Various magnetic-target fusion (MTF) reactor concepts involve a preliminary magnetic confinement stage, followed by a metallic liner implosion that compresses the plasma to fusion conditions. The process is repeated to produce a pulsed, net-gain energy system. General Fusion, Inc. is pursuing one scheme that involves the compression of spheromak plasmas inside a liner formed by a collapsing vortex of liquid Pb-Li. The compression is driven by focused acoustic waves launched by gas-driven piston impacts. Here we describe a project to exploring the effects of possible liner spallation during compression on the spheromaks temperature, lifetime, and stability. We employ a 1 J, 10 ns pulsed YAG laser at 532nm focused onto a thin film of Li or Al to inject a known quantity of metallic impurities into a spheromak plasma and then measure the response. Diagnostics including visible and ultraviolet spectrometers, ion Doppler, B-probes, and Thomson scattering are used for plasma characterization. We then plan to apply the trends measured under these controlled conditions to evaluate the role of wall impurities during `field shots', where spheromaks are compressed through a chemically driven implosion of an aluminum flux conserver. The hope is that with further study we could more accurately include the effect of wall impurities on the fusion yield of a reactor-scale MTF system. Experimental procedures and results are presented, along with their relation to other liner-driven, MTF schemes. -/a

  3. AN EVALUATION OF POTENTIAL LINER MATERIALS FOR ELIMINATING FCCI IN IRRADIATED METALLIC NUCLEAR FUEL ELEMENTS

    SciTech Connect

    D. D. Keiser; J. I. Cole

    2007-09-01

    Metallic nuclear fuels are being looked at as part of the Global Nuclear Energy Program for transmuting longlive transuranic actinide isotopes contained in spent nuclear fuel into shorter-lived fission products. In order to optimize the performance of these fuels, the concept of using liners to eliminate the fuel/cladding chemical interactions that can occur during irradiation of a fuel element has been investigated. The potential liner materials Zr and V have been tested using solid-solid diffusion couples, consisting of liner materials butted against fuel alloys and against cladding materials. The couples were annealed at the relatively high temperature of 700°C. This temperature would be the absolute maximum temperature present at the fuel/cladding interface for a fuel element in-reactor. Analysis was performed using a scanning electron microscope equipped with energy-dispersive and wavelengthdispersive spectrometers (SEM/EDS/WDS) to evaluate any developed diffusion structures. At 700°C, minimal interaction was observed between the metallic fuels and either Zr or V. Similarly, limited interaction was observed between the Zr and V and the cladding materials. The best performing liner material appeared to be the V, based on amounts of interaction.

  4. Transition duct system with metal liners for delivering hot-temperature gases in a combustion turbine engine

    DOEpatents

    Wiebe, David J.

    2017-04-11

    A transition duct system (10) for delivering hot-temperature gases from a plurality of combustors in a combustion turbine engine is provided. The system includes an exit piece (16) for each combustor. The exit piece may include a straight path segment (26) and an arcuate connecting segment (36). A respective straight metal liner (92) and an arcuate metal liner (94) may be each inwardly disposed onto a metal outer shell (38) along the straight path segment and the arcuate connecting segment (36) of the exit piece. Structural arrangements are provided to securely attach the respective liners in the presence of substantial flow path pressurization. Cost-effective serviceability of the transition duct systems is realizable since the liners can be readily removed and replaced as needed.

  5. Attenuation of FJ44 Turbofan Engine Noise with a Foam-Metal Liner Installed Over-the-Rotor

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.; Elliott, Dave M.; Jones, Michael G.; Hartley, Thomas C.

    2009-01-01

    A Williams International FJ44-3A 3000-lb thrust class turbofan engine was used as a demonstrator for a Foam-Metal Liner (FML) installed in close proximity to the fan. Two FML designs were tested and compared to the hardwall baseline. Traditional single degree-of-freedom liner designs were also evaluated to provide a comparison. Farfield acoustic levels and limited engine performance results are presented in this paper. The results show that the FML achieved up to 5 dB Acoustic Power Level (PWL) overall attenuation in the forward quadrant, equivalent to the traditional liner design. An earlier report presented the test set-up and conditions.

  6. Collaboration with Williams International to Demonstrate the Characteristics of a Foam-Metal-Liner Installed Over-the-Rotor of a Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel; Elliott, Dave; Jones, Mike; Hartley, Tom

    2008-01-01

    A Williams International FJ44-3A 3000-lb thrust class turbofan engine was used as a demonstrator for foam-metal liner installed in close proximity to the fan. Two foam metal liner designs were tested and compared to the hardwall. Traditional Single-Degree-of-Freedom liner designs were also evaluated to provide a comparison. Normalized information on farfield acoustics is presented in this paper. The results show that up to 5 dB PWL overall attenuation was achieved in the forward quadrant. In general, the foam-metal liners performed better when the fan tip speed was below sonic.

  7. Potential use of lateritic and marine clay soils as landfill liners to retain heavy metals.

    PubMed

    Chalermyanont, Tanit; Arrykul, Surapon; Charoenthaisong, Nanthanit

    2009-01-01

    The potential of a lateritic soil and a marine clay, typical of those found in hot and humid climatic regions, was assessed for use as a landfill liner material. A series of tests were conducted - physical and chemical, batch adsorption, column, hydraulic conductivity, etc., - to evaluate the heavy metal sorption capacity, chemical compatibility of hydraulic conductivity, and transport parameters of the soils. Experimental results showed that the marine clay had better adsorption capacity than that of the lateritic soil and that its hydraulic conductivity was an order of magnitude lower. In addition, the hydraulic conductivities of both soils when permeated with low concentration heavy metal solutions were below 1x10(-7)cm/s. When permeated with Cr, Pb, Cd, Zn, and Ni solutions, the retardation factors of the lateritic soil and the marine clay ranged from 10 to 98 and 37 to 165, respectively, while the diffusion coefficients ranged from 1.0x10(-5) to 7.5x10(-6) and 3.0 to 9.14x10(-7)cm2/s, respectively. For both soils, Cr and Pb were retained relatively well, while Cd, Zn, and Ni were more mobile. The marine clay had higher retardation factors and lower diffusion coefficients, and its hydraulic conductivity was more compatible with Cr solution, than that of the lateritic soil. In general, the properties of the marine clay indicate that it has significant advantages over the lateritic soil as landfill liner material.

  8. Enhanced highly charged ion production using a metal-dielectric liner in the KVI 14 GHz ECR ion source

    NASA Astrophysics Data System (ADS)

    Schachter, L.; Dobrescu, S.; Rodrigues, G.; Drentje, A. G.

    2002-02-01

    Forming on an aluminum surface a dielectric layer of alumina (aluminum oxide) in order to create a metal-dielectric (MD) structure increases the secondary-electron emission properties. The idea of using this material as a MD (Al-Al2O3) cylindrical liner inside an ECR ion source was previously tested in the 14 GHz ECRIS of IKF (Frankfurt/Main, Germany). The purpose of the present experiment was to observe the effect of such a MD liner on the high charge state operation of the KVI 14 GHz ECRIS, in particular in comparison to the technique of gas mixing. Measurements were made both with and without the MD liner, with pure argon and with an argon plus oxygen mixture. In the case of pure argon, the source with the MD liner is running remarkably stable. The high charge state ion beam currents are by far higher than those obtained in the situation where the source was operated with pure argon but without the MD liner. With MD liner, some low intensity oxygen peaks were clearly present in the spectra, implying that oxygen escaping or sputtered from the MD structure could give rise to an effect of "gas mixing." Therefore, the effect of mixing small amounts of oxygen into an argon plasma without the liner was studied in the same conditions of rf power and O3+ peak intensity. The conclusion was that the high charge state beam increase is not due to the oxygen gas mixing effect. The reason for the good performances of the source in the presence of the MD liner can be the increased density of cold electrons, but other effects could occur as well. This is subject of further studies.

  9. Finite-element and fracture-mechanics analyses of filament-wound pressure vessels with thin metallic liners

    SciTech Connect

    Shy, D.S.

    1987-01-01

    The theoretical background and concept are provided for analyzing the filament-wound pressure vessels with thin metallic liners. The thin metallic liner serves mainly as a permeation barrier to hold liquid or gas, while the composite is sized to carry most of the pressure loads. The bilinear material model is selected to simulate the material stress-strain curve that governs the metal linear behavior. Subjects investigated are classical lamination theory, quadratic failure criterion, bilinear material model, finite-element analysis for axisymmetric solids, and linear elastic fracture mechanics. Four sample cases are analyzed to demonstrate the capabilities of the developed finite-element program FEASY4ND in solving the axisymmetric shell problems. The cases investigated include the parametric study on Poisson's ratio, the thick-walled and thin-walled sphere analyses, and analysis of a sample filament-wound pressure vessel with a thin metallic liner. The filament-wound pressure vessel is analyzed at proof, operating, and design burst pressures. The liner cycle life is calculated based on the principle of linear elastic fracture mechanics.

  10. Conical shaped charge pressed powder, metal liner jet characterization and penetration in aluminum

    SciTech Connect

    Vigil, M.G.

    1997-05-01

    This work was conducted as part of a Near-wellbore Mechanics program at Sandia National Laboratories. An understanding of the interaction of the perforator jet from an explosive shaped charge with the fluid filled porous sandstone media is of basic importance to the completion of oil wells. Tests were conducted using the five-head Flash X-ray Test Site to measure the jet tip velocities and jet geometry for the OMNI and CAPSULE Conical Shaped Charge (CSC) oil well perforator jets fired into air. These tests were conducted to generate jet velocity and geometry information to be used in validating the CTH hydrocode modeling/simulation development of pressed powder, metal liner jets in air. Ten tests were conducted to determine the CSC jet penetration into 6061-T6 aluminum targets. Five tests were conducted with the OMNI CSC at 0.25, 6.0, and 19 inch standoffs from the target. Five tests were conducted with the CAPSULE CSC at 0.60, 5.0, 10.0, and 19 inch standoffs from the target. These tests were conducted to generate jet penetration into homogeneous target information for use in validating the CTH code modeling/simulation of pressed powder, metal liner jets penetrating aluminum targets. The Flash X-ray radiographs, jet velocities, jet diameters, and jet lengths data for jets fired into air are presented in this report. The jet penetration into aluminum and penetration hole profile data are also presented for the OMNI and CAPSULE perforators. Least Squares fits are presented for the measured jet velocity and jet penetration data.

  11. Adsorption of oils, heavy metals and dyes by recovered carbon powder from spent pot liner of aluminum smelter plant.

    PubMed

    Mazumder, B; Devi, Sasmita Rani

    2008-07-01

    Aluminum smelter plants employ Hall-Heroult electrolysis cells for electrolysis of molten cryolite to recover aluminum metal by electrolysis. These cells use carbon cathode blocks as a lining material inside. At the end of service life of the cells, pot lines are discarded and new carbon blocks are laid for fresh charging. These used carbon cathode blocks, known as spent pot liners, are heavily infested with toxic elements such as fluoride, cyanide, alkali, etc. Therefore, their disposal in open field poses great environmental risk. A simple process has been developed for decontamination of these spent pot liners and to recover its carbon value. The experiments indicated that this carbon, in the form of fine powder (around 20 micron in size) can absorb toxic elements like heavy metals, dyes, oils, etc. to a great extent and thus can be used for mitigating environmental pollution occuring due to various toxic wastes.

  12. Experimental demonstration of the stabilizing effect of dielectric coatings on magnetically accelerated imploding metallic liners

    SciTech Connect

    Awe, Thomas James; Peterson, Kyle J.; Yu, Edmund P.; McBride, Ryan D.; Sinars, Daniel B.; Gomez, Matthew R.; Jennings, Christopher Ashley; Martin, Matthew R.; Rosenthal, Stephen E.; Sefkow, Adam B.; Slutz, Stephen A.; Vesey, Roger A.; Schroen, D. G.; Tomlinson, Kurt

    2016-02-10

    Enhanced implosion stability has been experimentally demonstrated for magnetically accelerated liners that are coated with 70 μm of dielectric. The dielectric tamps liner-mass redistribution from electrothermal instabilities and also buffers coupling of the drive magnetic field to the magneto-Rayleigh-Taylor instability. A dielectric-coated and axially premagnetized beryllium liner was radiographed at a convergence ratio [CR=Rin,0/Rin(z,t)] of 20, which is the highest CR ever directly observed for a strengthless magnetically driven liner. Lastly, the inner-wall radius Rin(z,t) displayed unprecedented uniformity, varying from 95 to 130 μm over the 4.0 mm axial height captured by the radiograph.

  13. Experimental demonstration of the stabilizing effect of dielectric coatings on magnetically accelerated imploding metallic liners

    DOE PAGES

    Awe, Thomas James; Peterson, Kyle J.; Yu, Edmund P.; ...

    2016-02-10

    Enhanced implosion stability has been experimentally demonstrated for magnetically accelerated liners that are coated with 70 μm of dielectric. The dielectric tamps liner-mass redistribution from electrothermal instabilities and also buffers coupling of the drive magnetic field to the magneto-Rayleigh-Taylor instability. A dielectric-coated and axially premagnetized beryllium liner was radiographed at a convergence ratio [CR=Rin,0/Rin(z,t)] of 20, which is the highest CR ever directly observed for a strengthless magnetically driven liner. Lastly, the inner-wall radius Rin(z,t) displayed unprecedented uniformity, varying from 95 to 130 μm over the 4.0 mm axial height captured by the radiograph.

  14. Experimental Demonstration of the Stabilizing Effect of Dielectric Coatings on Magnetically Accelerated Imploding Metallic Liners

    NASA Astrophysics Data System (ADS)

    Awe, T. J.; Peterson, K. J.; Yu, E. P.; McBride, R. D.; Sinars, D. B.; Gomez, M. R.; Jennings, C. A.; Martin, M. R.; Rosenthal, S. E.; Schroen, D. G.; Sefkow, A. B.; Slutz, S. A.; Tomlinson, K.; Vesey, R. A.

    2016-02-01

    Enhanced implosion stability has been experimentally demonstrated for magnetically accelerated liners that are coated with 70 μ m of dielectric. The dielectric tamps liner-mass redistribution from electrothermal instabilities and also buffers coupling of the drive magnetic field to the magneto-Rayleigh-Taylor instability. A dielectric-coated and axially premagnetized beryllium liner was radiographed at a convergence ratio [CR =Rin,0/Rin(z ,t ) ] of 20, which is the highest CR ever directly observed for a strengthless magnetically driven liner. The inner-wall radius Rin(z ,t ) displayed unprecedented uniformity, varying from 95 to 130 μ m over the 4.0 mm axial height captured by the radiograph.

  15. Experimental Demonstration of the Stabilizing Effect of Dielectric Coatings on Magnetically Accelerated Imploding Metallic Liners.

    PubMed

    Awe, T J; Peterson, K J; Yu, E P; McBride, R D; Sinars, D B; Gomez, M R; Jennings, C A; Martin, M R; Rosenthal, S E; Schroen, D G; Sefkow, A B; Slutz, S A; Tomlinson, K; Vesey, R A

    2016-02-12

    Enhanced implosion stability has been experimentally demonstrated for magnetically accelerated liners that are coated with 70  μm of dielectric. The dielectric tamps liner-mass redistribution from electrothermal instabilities and also buffers coupling of the drive magnetic field to the magneto-Rayleigh-Taylor instability. A dielectric-coated and axially premagnetized beryllium liner was radiographed at a convergence ratio [CR=Rin,0/Rin(z,t)] of 20, which is the highest CR ever directly observed for a strengthless magnetically driven liner. The inner-wall radius Rin(z,t) displayed unprecedented uniformity, varying from 95 to 130  μm over the 4.0 mm axial height captured by the radiograph.

  16. Outcomes of polyethylene liner cementation into a fixed metal acetabular shell with minimum follow-up of 7 years.

    PubMed

    Park, Myung-Sik; Yoon, Sun-Jung; Lee, Ju Rang

    2015-01-01

    Cementation of a polyethylene liner into the well-fixed shell is a convenient option for revision total hip arthroplasty. We retrospectively reviewed 45 patients who had liner cementation to investigate the risk factors which gave rise to major complications and reoperation. Patients were observed for a minimum of 7 years (range 7.8-14 years). Relevant risk factors (age, BMI, surgical approach, previous cup size and position, types of coated surface) were assessed with Cox regression analysis. The mean Harris Hip Score was improved from 62.5 (range 57-68) preoperatively to 87.1 (range 70-97). A total of 7 hips (15.5%) had acetabular component loosening that was treated with reoperation. Prevalence of acetabular component loosening was statistically significantly higher in hydroxyapatite-coated group (5 of 13) than in the Ti-coated group (2 of 32, p = 0.015). All recurrent dislocations occurred in patients treated with a posterior approach. Diameter of the previous metal shell of below 54 mm showed a lower 10-year survival rate than those greater than 54 mm in diameter. PE liner cementation in stable metal cup is a useful alternative option for carefully selected patients. Pre-existing HA-coated cups as well as small sized cups were indicative of poor outcomes.

  17. Nucleation, wetting and agglomeration of copper and copper-alloy thin films on metal liner surfaces

    NASA Astrophysics Data System (ADS)

    LaBarbera, Stephanie Florence

    One of the key challenges in fabricating narrower and higher aspect ratio interconnects using damascene technology has been achieving an ultra-thin (˜2 nm) and continuous Cu seed coverage on trench sidewalls. The thin seed is prone to agglomeration because of poor Cu wetting on the Ta liner. Using in-situ conductance measurements, the effect of lowering the substrate temperature during Cu seed deposition has been studied on tantalum (Ta) and ruthenium (Ru) liner surfaces. On a Ta surface, it was found that lowering the deposition temperature to --65°C increases the nucleation rate of the Cu thin film, and reduces the minimum coalescing thickness for Cu on Ta liner from ˜4.5 nm (at room temperature) to ˜2 nm. On a Ru surface, Cu coalesces at < 1 nm at room temperature, and no further reduction in initial coalescing thickness was found at low temperature. For the Cu seed deposited at --65°C on a Ta liner on trench sidewalls, extensive thermal stress-induced grain growth was observed during warming up to room temperature. No grain growth was observed in the seed layer deposited at low temperatures on a Ru liner. Small feature size and high current densities make electromigration an important concern for on-chip Cu interconnects. Cu-alloy seeds or Cu-alloy interconnects are therefore needed for future technology. The wetting angle, coalescing thickness, and agglomeration resistance of thin Cu-3% Au, Cu-3% Mn, and Cu-3% Al layers on a Ta liner surface have been studied. It was found that the alloying increases the wetting angle of Cu on Ta at high temperature, as a result of either reduction in Cu alloy surface energy, solute surface segregation, or solute-liner interactions. In addition, the Cu alloys were found to be less agglomeration resistive as compared to pure Cu; their smaller grain size, interaction with the liner surface, and tendency to oxidize were found to accelerate their agglomeration. The coalescing thickness of the Cu alloys was found to be reduced

  18. Investigation of a Bulk Metallic Glass as a Shaped Charge Liner Material

    DTIC Science & Technology

    2006-08-01

    corresponding energy dispersive X-ray spectroscopic analyses for the top intermix layer...were designed to determine the free -flight jet characteristics, and the final shot was for penetration. The tests were conducted at the...second free -flight radiography test designed to examine the jet more closely now that the tip velocity was accurately known. This test used liner 25

  19. The Nature of LINERS

    NASA Astrophysics Data System (ADS)

    Alonso-Herrero, Almudena; Rieke, Marcia J.; Rieke, George H.; Shields, Joseph C.

    2000-02-01

    We present J-band (1.15-1.35 μm) spectroscopy of a sample of nine galaxies showing some degree of LINER activity (classical LINERs, weak-[O I] LINERs, and transition objects), together with H-band spectroscopy for some of them. A careful subtraction of the stellar continuum allows us to obtain reliable [Fe II] 1.2567 μm/Paβ line ratios. We conclude that different types of LINERs (i.e., photoionized by a stellar continuum or by an active galactic nucleus) cannot be easily distinguished based solely on the [Fe II] 1.2567 μm/Paβ line ratio. The emission-line properties of many LINERs can be explained in terms of an aging starburst. The optical line ratios of these LINERs are reproduced by a model with a metal-rich H II region component photoionized with a single stellar temperature T*=38,000 K, plus a supernova remnant (SNR) component. The [Fe II] line is predominantly excited by shocks produced by SNRs in starbursts and starburst-dominated LINERs, while Paβ tracks H II regions ionized by massive young stars. The contribution from SNRs to the overall emission-line spectrum is constrained by the [Fe II] 1.2567 μm/Paβ line ratio. Although our models for aging starbursts are constrained only by these infrared lines, they consistently explain the optical spectra of the galaxies also. The LINER-starburst connection is tested by predicting the time dependence of the ratio of the ionizing luminosity (Lion) to the supernova rate (SNr), Lion/(SNr). We predict the relative number of starbursts to starburst-dominated LINERs (aging starbursts) and show that it is in approximate agreement with survey findings for nearby galaxies. Observations reported in this paper were obtained with the Multiple Mirror Telescope, which is operated jointly by the Smithsonian Astrophysical Observatory and the University of Arizona.

  20. LINER FOR EXTRUSION BILLET CONTAINERS

    DTIC Science & Technology

    Shrink-fit assembly device for buildup of ceramic-coated liner and sleeve assemblies was tested and modified to develop desired temperatures and...preliminary evaluation of suitability for extrusion liner use. Procedures were developed for welding short, hollow ceramic cylinders of high-strength metal...carbides and borides to form a ceramic extrusion liner of suitable length. Disassembly tooling for rapid separation of shrink-fitted sleeves from a worn

  1. Magnesium Fluoride Reduction Vessel Liners

    DTIC Science & Technology

    1986-03-26

    Carolina Metals, the fluoride is reduced to power by means of a Mikro #2 hemmer mill (Figure 5). The material is then separated into the different...The jolter table previously referred to in the liner pro - ceasing operation, is the knockout station. As shown in Figure 36, the vessel is inverted...was much more extensive than normally performed to establish the quality of thý metal pro - duced using the MgF2 liners. There are no indications of

  2. Study of Strain Induction for Metal-Oxide-Semiconductor Field-Effect Transistors using Transparent Dummy Gates and Stress Liners

    NASA Astrophysics Data System (ADS)

    Kosemura, Daisuke; Takei, Munehisa; Nagata, Kohki; Akamatsu, Hiroaki; Kohno, Masayuki; Nishita, Tatsuo; Nakanishi, Toshio; Ogura, Atsushi

    2009-06-01

    Strain induction was studied on a sample that had a dummy gate tetraethyl orthosilicate-silicon dioxide (TEOS-SiO2) and SiN film by UV-Raman spectroscopy with high spatial and high wave-number resolution. The UV laser penetrated through the dummy gate that was transparent to UV light, which enabled us to evaluate strain in the channel of the metal-oxide-semiconductor field-effect transistor (MOSFET) model. Furthermore, we compared stress profiles obtained by finite element (FE) calculations with those obtained by UV-Raman measurements. There was a difference between the stress profiles in the line-and-space pattern sample and in the dummy-gate sample; large compressive (tensile) strains were concentrated at the channel edges in the dummy-gate sample with the compressive (tensile) stress liner, although both tensile and compressive strains existed at the channel edge in the line-and-space pattern sample. The results from UV-Raman spectroscopy were consistent with those obtained by the FE calculation.

  3. Explosively Bonded Gun Tube Liner Development

    DTIC Science & Technology

    2015-04-01

    efforts identified several promising materials that could be used for liners, primarily refractory metals such as tantalum (Ta), molybdenum (Mo...Characterization of tantalum liners applied to 25-mm and 120-mm cannon bore sections via explosive bonding. Watervliet (NY): Benét Laboratories (US...fired tantalum liners applied to 25mm gun tubes. Watervliet (NY): Benét Laboratories; 2001 Nov. Report No.: ARCCB-TR-02016. 9. Pepi M, Snoha D

  4. Blocking Metal Accretion onto Population III Stars by Stellar Wind

    NASA Astrophysics Data System (ADS)

    Tanaka, Shuta J.; Chiaki, Gen; Tominaga, Nozomu; Susa, Hajime

    2017-08-01

    Low-mass population III (PopIII) stars of ≲ 0.8 {M}⊙ could survive up until the present. The nondetection of low-mass PopIII stars in our Galaxy has already put a stringent constraint on the initial mass function (IMF) of PopIII stars, suggesting that PopIII stars have a top-heavy IMF. On the other hand, some claim that the lack of such stars stems from metal enrichment of their surfaces by the accretion of heavy elements from the interstellar medium (ISM). We investigate the effects of the stellar wind on metal accretion onto low-mass PopIII stars because accretion of the local ISM onto the Sun is prevented by the solar wind, even for neutrals. The stellar wind and radiation of low-mass PopIII stars are modeled based on knowledge of nearby low-mass stellar systems, including our Sun. We find that low-mass PopIII stars traveling across the Galaxy form a stellar magnetosphere in most of their life. Once the magnetosphere is formed, most of the neutral interstellar particles are photoionized before reaching the stellar surface and are blown away by the wind. Especially, the accretion abundance of iron will be reduced by a factor of < {10}-12 compared with Bondi-Hoyle-Lyttleton accretion. The metal accretion can enhance iron abundance [Fe/H] only up to ˜-14. This demonstrates that low-mass PopIII stars remain pristine and will be found as metal-free stars and that further searches for them are valuable in constraining the IMF of PopIII stars.

  5. Evaluating the Acoustic Effect of Over-the-Rotor Foam-Metal Liner Installed on a Low Speed Fan Using Virtual Rotating Microphone Imaging

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.; Dougherty, Robert P.; Walker, Bruce E.

    2010-01-01

    An in-duct beamforming technique for imaging rotating broadband fan sources has been used to evaluate the acoustic characteristics of a Foam-Metal Liner installed over-the-rotor of a low-speed fan. The NASA Glenn Research Center s Advanced Noise Control Fan was used as a test bed. A duct wall-mounted phased array consisting of several rings of microphones was employed. The data are mathematically resampled in the fan rotating reference frame and subsequently used in a conventional beamforming technique. The steering vectors for the beamforming technique are derived from annular duct modes, so that effects of reflections from the duct walls are reduced.

  6. Thermodynamically stable Metal/III-V compound-semiconductor interfaces

    NASA Astrophysics Data System (ADS)

    Williams, R. S.; Lince, J. R.; Tsai, C. T.; Pugh, J. H.

    1986-02-01

    Chemical reactions that occur at a metal/III-V compound-semiconductor interface should be minimized if the change in Gibbs free energy of the bulk materials with respect to any possible reaction products is positive. However, the large positive change in entropy caused by vaporization of the highly volatile group V elements is a very important contribution to the Gibbs free energy of these systems, especially at higher temperatures. Thus, a particular metal/III-V compound-semiconductor interface may be thermodynamically stable at one temperature, but unstable with respect to sublimation of elemental group V species at a higher temperature if the enthalpy change for the reaction is positive. Examination of bulk phase diagrams makes it possible to rationalize the reaction products observed and to predict which will be the most stable interface for any particular metal/III-V system.

  7. Prediction of Heavy Metal Removal by Different Liner Materials from Landfill Leachate: Modeling of Experimental Results Using Artificial Intelligence Technique

    PubMed Central

    Turan, Nurdan Gamze; Gümüşel, Emine Beril; Ozgonenel, Okan

    2013-01-01

    An intensive study has been made to see the performance of the different liner materials with bentonite on the removal efficiency of Cu(II) and Zn(II) from industrial leachate. An artificial neural network (ANN) was used to display the significant levels of the analyzed liner materials on the removal efficiency. The statistical analysis proves that the effect of natural zeolite was significant by a cubic spline model with a 99.93% removal efficiency. Optimization of liner materials was achieved by minimizing bentonite mixtures, which were costly, and maximizing Cu(II) and Zn(II) removal efficiency. The removal efficiencies were calculated as 45.07% and 48.19% for Cu(II) and Zn(II), respectively, when only bentonite was used as liner material. However, 60% of natural zeolite with 40% of bentonite combination was found to be the best for Cu(II) removal (95%), and 80% of vermiculite and pumice with 20% of bentonite combination was found to be the best for Zn(II) removal (61.24% and 65.09%). Similarly, 60% of natural zeolite with 40% of bentonite combination was found to be the best for Zn(II) removal (89.19%), and 80% of vermiculite and pumice with 20% of bentonite combination was found to be the best for Zn(II) removal (82.76% and 74.89%). PMID:23844384

  8. Prediction of heavy metal removal by different liner materials from landfill leachate: modeling of experimental results using artificial intelligence technique.

    PubMed

    Turan, Nurdan Gamze; Gümüşel, Emine Beril; Ozgonenel, Okan

    2013-01-01

    An intensive study has been made to see the performance of the different liner materials with bentonite on the removal efficiency of Cu(II) and Zn(II) from industrial leachate. An artificial neural network (ANN) was used to display the significant levels of the analyzed liner materials on the removal efficiency. The statistical analysis proves that the effect of natural zeolite was significant by a cubic spline model with a 99.93% removal efficiency. Optimization of liner materials was achieved by minimizing bentonite mixtures, which were costly, and maximizing Cu(II) and Zn(II) removal efficiency. The removal efficiencies were calculated as 45.07% and 48.19% for Cu(II) and Zn(II), respectively, when only bentonite was used as liner material. However, 60% of natural zeolite with 40% of bentonite combination was found to be the best for Cu(II) removal (95%), and 80% of vermiculite and pumice with 20% of bentonite combination was found to be the best for Zn(II) removal (61.24% and 65.09%). Similarly, 60% of natural zeolite with 40% of bentonite combination was found to be the best for Zn(II) removal (89.19%), and 80% of vermiculite and pumice with 20% of bentonite combination was found to be the best for Zn(II) removal (82.76% and 74.89%).

  9. Obtaining off-Hugoniot equation of state data on solid metals at extreme pressures via pulsed-power driven cylindrical liner implosions

    NASA Astrophysics Data System (ADS)

    Lemke, Raymond

    2015-06-01

    The focus of this talk is on magnetically driven, liner implosion experiments on the Z machine (Z) in which a solid, metal tube is shocklessly compressed to multi-megabar pressure. The goal of the experiments is to collect velocimetry data that can be used in conjunction with a new optimization based analysis technique to infer the principal isentrope of the tube material over a range of pressures. For the past decade, shock impact and ramp loading experiments on Z have used planar platforms exclusively. While producing state-of-the-art results for material science, it is difficult to produce drive pressures greater than 6 Mbar in the divergent planar geometry. In contrast, a cylindrical liner implosion is convergent; magnetic drive pressures approaching 50 Mbar are possible with the available current on Z (~ 20 MA). In our cylindrical experiments, the liner comprises an inner tube composed of the sample material (e.g., Ta) of unknown equation of state, and an outer tube composed of aluminum (Al) that serves as the current carrying cathode. Internal to the sample are fielded multiple PDV (Photonic Doppler Velocimetry) probes that measure velocity of the inner free surface of the imploding sample. External to the composite liner, at much larger radius, is an Al tube that is the return current anode. VISAR (velocity interferometry system for any reflector) probes measure free surface velocity of the exploding anode. Using the latter, MHD and optimization codes are employed to solve an inverse problem that yields the current driving the liner implosion. Then, the drive current, PDV velocity, MHD and optimization codes, are used to solve another inverse problem that yields pressure vs. density on approximately the principal isentrope of the sample material. Results for Ta, Re, and Cu compressed to ~ 10 Mbar are presented. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin

  10. Synthesis, thermal and spectroscopic behaviors of metal-drug complexes: La(III), Ce(III), Sm(III) and Y(III) amoxicillin trihydrate antibiotic drug complexes.

    PubMed

    Refat, Moamen S; Al-Maydama, Hussein M A; Al-Azab, Fathi M; Amin, Ragab R; Jamil, Yasmin M S

    2014-07-15

    The metal complexes of Amoxicillin trihydrate with La(III), Ce(III), Sm(III) and Y(III) are synthesized with 1:1 (metal:Amox) molar ratio. The suggested formula structures of the complexes are based on the results of the elemental analyses, molar conductivity, (infrared, UV-visible and fluorescence) spectra, effective magnetic moment in Bohr magnetons, as well as the thermal analysis (TG), and characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results obtained suggested that Amoxicillin reacted with metal ions as tridentate ligands, coordinating the metal ion through its amino, imino, and β-lactamic carbonyl. The kinetic thermodynamic parameters such as: Ea, ΔH(*), ΔS(*) and ΔG(*) were estimated from the DTG curves.

  11. Synthesis and in vitro microbial evaluation of La(III), Ce(III), Sm(III) and Y(III) metal complexes of vitamin B6 drug

    NASA Astrophysics Data System (ADS)

    Refat, Moamen S.; Al-Azab, Fathi M.; Al-Maydama, Hussein M. A.; Amin, Ragab R.; Jamil, Yasmin M. S.

    2014-06-01

    Metal complexes of pyridoxine mono hydrochloride (vitamin B6) are prepared using La(III), Ce(III), Sm(III) and Y(III). The resulting complexes are investigated. Some physical properties, conductivity, analytical data and the composition of the four pyridoxine complexes are discussed. The elemental analysis shows that the formed complexes of La(III), Ce(III), Sm(III) and Y(III) with pyridoxine are of 1:2 (metal:PN) molar ratio. All the synthesized complexes are brown in color and possess high melting points. These complexes are partially soluble in hot methanol, dimethylsulfoxide and dimethylformamide and insoluble in water and some other organic solvents. Elemental analysis data, spectroscopic (IR, UV-vis. and florescence), effective magnetic moment in Bohr magnetons and the proton NMR suggest the structures. However, definite particle size is determined by invoking the X-ray powder diffraction and scanning electron microscopy data. The results obtained suggested that pyridoxine reacted with metal ions as a bidentate ligand through its phenolate oxygen and the oxygen of the adjacent group at the 4‧-position. The molar conductance measurements proved that the pyridoxine complexes are electrolytic in nature. The kinetic and thermodynamic parameters such as: Ea, ΔH*, ΔS* and ΔG* were estimated from the DTG curves. The antibacterial evaluation of the pyridoxine and their complexes were also performed against some gram positive, negative bacteria as well as fungi.

  12. Gun Liner Emplacement With an Elastomeric Material

    DTIC Science & Technology

    2010-04-01

    Include area code) 410 -306-0816 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 iii Contents List of Figures iv  List of Tables v...12  Figure 9. Inner diameter measurements for Stellite liners no. 1 and 2...5  Table 2. Bond strength results for 4-in Stellite 25 liners ................................................................6  Table 3. Bond

  13. Uncemented third-generation ceramic-on-ceramic total hip arthroplasty using metal acetabular shell with direct taper locking liner.

    PubMed

    Tsukada, Sachiyuki; Wakui, Motohiro; Matsueda, Munenori

    2013-06-01

    The ceramic-on-ceramic (CoC)-bearing couple in total hip arthroplasty (THA) was developed to reduce the wear debris and osteolysis. Although the mechanical strength of third-generation ceramic has improved over previous generations, the risk of osteolysis and ceramic fracture is still an important concern. We studied 124 uncemented THAs with third-generation CoC-bearing couple implanted between 2000 and 2004. The ceramic liner and head were secured with the direct taper locking mechanism. One hundred and eleven hips were followed-up for minimum of 8 years, with an average follow-up period of 10.1 years (range 8.0-12.8 years). Patients were evaluated with a particular emphasis on the prevalence of the osteolysis and the ceramic fracture. The survivorship with the end point as implant revision for any reason was 94.9 % (95 % confidence intervals 90.0-99.3 %) at 12.8 years. Revisions were performed because of one ceramic liner fracture, three dislocations, and two deep infections. No radiographic evidence of wear or osteolysis was observed. The preoperative Merle d'Aubigne and Postel hip score increased from 11.6 to 17.1. Patients, who received third-generation CoC THA had no detectable wear and osteolysis. One ceramic fracture occurred, and the main reason for revision was dislocation.

  14. Acoustic Liner for Turbomachinery Applications

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.; Sutliff, Daniel L.; Jones, Michael G.; Hebsur, Mohan G.

    2010-01-01

    The purpose of this innovation is to reduce aircraft noise in the communities surrounding airports by significantly attenuating the noise generated by the turbomachinery, and enhancing safety by providing a containment barrier for a blade failure. Acoustic liners are used in today's turbofan engines to reduce noise. The amount of noise reduction from an acoustic liner is a function of the treatment area, the liner design, and the material properties, and limited by the constraints of the nacelle or casement design. It is desirable to increase the effective area of the acoustic treatment to increase noise suppression. Modern turbofan engines use wide-chord rotor blades, which means there is considerable treatment area available over the rotor tip. Turbofan engines require containment over the rotors for protection from blade failure. Traditional methods use a material wrap such as Kevlar integrated with rub strips and sometimes metal layers (sandwiches). It is possible to substitute the soft rub-strip material with an open-cell metallic foam that provides noise-reduction benefits and a sacrificial material in the first layer of the containment system. An open-cell foam was evaluated that behaves like a bulk acoustic liner, serves as a tip rub strip, and can be integrated with a rotor containment system. Foams can be integrated with the fan-containment system to provide sufficient safety margins and increased noise attenuation. The major innovation is the integration of the foam with the containment.

  15. Voluntary Consensus Organization Standards for Nondestructive Evaluation of Thin-Walled Metallic Liners and Composite Overwraps in Composite Overwrapped Pressure Vessels

    NASA Technical Reports Server (NTRS)

    Waller, Jess; Saulsberry, Regor

    2012-01-01

    NASA fracture control requirements outlined in NASA-STD-5009 and NASA-STD-5014 are predicated on the availability and use of sensitive nondestructive evaluation (NDE) methods that can detect and monitor defects, thereby providing data that can be used to predict failure or reduce the risk of failure in fracture critical components. However, in the case of composite materials and components, including composite overwrapped pressure vessels (COPVs), the effect of defects is poorly understood, the NDE methods used to evaluate locate and size defects are typically at lower technical readiness level than analogous NDE methods used for metals, and demonstration studies to verify the probability of detection (POD) are generally lacking or unavailable. These factors together make failure prediction of fracture critical composite materials and components based on size, quantity, or orientation of defects nearly impossible. Also, when inspecting metal liners in as-manufactured COPVs, sensitivity is lost and only the inner surface of the liner is accessible. Also, NDE of COPVs as applied during manufacturing varies significantly from manufacturer to manufacturer and has not yet been standardized. Although requirements exist to perform NDE immediately after manufacturing to establish initial integrity of the parts, procedural detail for NDE of composites is still nonexistent or under development. For example, in practice, only a visual inspection of COPVs is performed during manufacturing and service, leaving in question whether defects of concern, for example, bridging, overwrap winding anomalies, impact damage below visible threshold, out-of-family strain growth, and liner buckling have been adequately detected and monitored. To address these shortcomings, in 2005 the NASA Nondestructive Evaluation Working Group (NNWG) began funding work to develop and adopt standards for nondestructive evaluation of aerospace composites in collaboration with the American Society for Testing

  16. Progress Report on Rotating Liquid Liner Implosion Experiment, 1 June to 31 December 1975.

    DTIC Science & Technology

    A critical question in the use of imploding liner flux compression for controlled fusion has been the stability of the inner surface of the liner ...To study the problem experimentally, the existing NRL Imploding Liner Facility was modified to allow the implosion of rotating liquid metal liners ...Rotational stabilization of lthe inner surface of a decelerating liquid sodium-potassium liner has been demonstrated, with excellent circularity of the

  17. Synthesis and stability of homoleptic metal(III) tetramethylaluminates.

    PubMed

    Occhipinti, Giovanni; Meermann, Christian; Dietrich, H Martin; Litlabø, Rannveig; Auras, Florian; Törnroos, Karl W; Maichle-Mössmer, Cäcilia; Jensen, Vidar R; Anwander, Reiner

    2011-04-27

    Whereas a number of homoleptic metal(III) tetramethylaluminates M(AlMe(4))(3) of the rare earth metals have proven accessible, the stability of these compounds varies strongly among the metals, with some even escaping preparation altogether. The differences in stability may seem puzzling given that this class of metals usually is considered to be relatively uniform with respect to properties. On the basis of quantum chemically obtained relative energies and atomic and molecular descriptors of homoleptic tris(tetramethylaluminate) and related compounds of rare earth metals, transition metals, p-block metals, and actinides, multivariate modeling has identified the importance of ionic metal-methylaluminate bonding and small steric repulsion between the methylaluminate ligands for obtaining stable homoleptic compounds. Low electronegativity and a sufficiently large ionic radius are thus essential properties for the central metal atom. Whereas scandium and many transition metals are too small and too electronegative for this task, all lanthanides and actinides covered in this study are predicted to give homoleptic compounds stable toward loss of trimethylaluminum, the expected main decomposition reaction. Three of the predicted lanthanide-based compounds Ln(AlMe(4))(3) (Ln = Ce, Tm, Yb) have been prepared and fully characterized in the present work, in addition to Ln(OCH(2)tBu)(3)(AlMe(3))(3) (Ln = Sc, Nd) and [Eu(AlEt(4))(2)](n). At ambient temperature, donor-free hexane solutions of Ln(AlMe(4))(3) of the Ln(3+)/Ln(2+) redox-active metal centers display enhanced reduction to [Ln(AlMe(4))(2)](n) with decreasing negative redox potential, in the order Eu ≫ Yb ≫ Sm. Whereas Eu(AlMe(4))(3) could not be identified, Yb(AlMe(4))(3) turned out to be isolable in low yield. All attempts to prepare the putative Sc(AlMe(4))(3), featuring the smallest rare earth metal center, failed.

  18. Time of Flight Measurements of a Plasma Plume in a Glass Tube With and Without a Metal Liner

    NASA Astrophysics Data System (ADS)

    Fiedler Kawaguchi, C.; Schaffner, D. A.; Brown, M. R.; Kaur, M.; Johnson, H. K.

    2016-10-01

    Researchers have yet to attain a self-sustaining fusion reaction in which the amount of energy put in is less than that being produced. A novel approach for the compression and heating of plasma is under development at Swarthmore College with collaboration from Bryn Mawr College through the ARPA-E ALPHA program. Two acceleration modules are being designed to accelerate and compress plasma plumes using pulsed copper rings outside of a glass chamber (module one) and inside of a stainless steel chamber (module two). Measurements of plasma velocity are made using a time of flight technique using Hall probes and magnetic pickup probes (B-dot) probes to measure magnetic field at an array of spatial locations along the chamber. Results shows that the response time of the Hall probe chip used was too slow to register the fast changing fields. B-dot probes were shown to have a fast enough response. Time of flight measurements of field are made in the glass tube using cross correlation methods, with and without a stainless steel liner. Preliminary results show an average increase in the plasma plume velocity, from 38 km/s to 45 km/s, when the glass chamber is lined. Work supported by ARPA-E ALPHA program.

  19. Thin-metal lined PRD 49-III composite vessels. [evaluation of pressure vessels for burst strength and fatigue performance

    NASA Technical Reports Server (NTRS)

    Hoggatt, J. T.

    1974-01-01

    Filament wound pressure vessels of various configurations were evaluated for burst strength and fatigue performance. The dimensions and characteristics of the vessels are described. The types of tests conducted are explained. It was determined that all vessels leaked in a relatively few cycles (20 to 60 cycles) with failure occurring in all cases in the metallic liner. The thin liner would de-bond from the composite and buckling took place during depressurization. No composite failures or indications of impeding composite failures were obtained in the metal-lined vessels.

  20. Probing the Physics of Narrow-line Regions in Active Galaxies. III. Accretion and Cocoon Shocks in the LINER NGC 1052

    NASA Astrophysics Data System (ADS)

    Dopita, Michael A.; Ho, I.-Ting; Dressel, Linda L.; Sutherland, Ralph; Kewley, Lisa; Davies, Rebecca; Hampton, Elise; Shastri, Prajval; Kharb, Preeti; Jose, Jessy; Bhatt, Harish; Ramya, S.; Scharwächter, Julia; Jin, Chichuan; Banfield, Julie; Zaw, Ingyin; James, Bethan; Juneau, Stéphanie; Srivastava, Shweta

    2015-03-01

    We present Wide Field Spectrograph integral field spectroscopy and Hubble Space Telescope Faint Object Spectrograph spectroscopy for the low-ionization nuclear emission line region (LINER) galaxy NGC 1052. We infer the presence of a turbulent accretion flow forming a small-scale accretion disk. We find a large-scale outflow and ionization cone along the minor axis of the galaxy. Part of this outflow region is photoionized by the active galactic nucleus and shares properties with the extended narrow-line region of Seyfert galaxies, but the inner (R≲ 1.0″) accretion disk and the region around the radio jet appear shock excited. The emission-line properties can be modeled by a “double-shock” model in which the accretion flow first passes through an accretion shock in the presence of a hard X-ray radiation, and the accretion disk is then processed through a cocoon shock driven by the overpressure of the radio jets. This model explains the observation of two distinct densities (˜104 and ˜106 cm-3) and provides a good fit to the observed emission-line spectrum. We derive estimates for the velocities of the two shock components and their mixing fractions, the black hole mass, and the accretion rate needed to sustain the LINER emission and derive an estimate for the jet power. Our emission-line model is remarkably robust against variation of input parameters and hence offers a generic explanation for the excitation of LINER galaxies, including those of spiral type such as NGC 3031 (M81).

  1. Synthesis of Imine-Naphthol Tripodal Ligand and Study of Its Coordination Behaviour towards Fe(III), Al(III), and Cr(III) Metal Ions

    PubMed Central

    Kaur, Kirandeep

    2014-01-01

    A hexadentate Schiff base tripodal ligand is synthesized by the condensation of tris (2-aminoethyl) amine with 2-hydroxy-1-naphthaldehyde and characterized by various spectroscopic techniques like UV-VIS, IR, NMR, MASS, and elemental analysis. The solution studies by potentiometric and spectrophotometric methods are done at 25 ± 1°C, µ = 0.1 M KCl, to calculate the protonation constants of the ligand and formation constants of metal complexes formed by the ligand with Fe(III), Al(III), and Cr(III) metal ions. The affinity of the ligand towards Fe(III) is compared with deferiprone (a drug applied for iron intoxication) and transferrin (the main Fe(III) binding protein in plasma). Structural analysis of the ligand and the metal complexes was done using semiempirical PM6 method. Electronic and IR spectra are calculated by semiempirical methods and compared with experimental one. PMID:25294978

  2. Development of 1D Liner Compression Code for IDL

    NASA Astrophysics Data System (ADS)

    Shimazu, Akihisa; Slough, John; Pancotti, Anthony

    2015-11-01

    A 1D liner compression code is developed to model liner implosion dynamics in the Inductively Driven Liner Experiment (IDL) where FRC plasmoid is compressed via inductively-driven metal liners. The driver circuit, magnetic field, joule heating, and liner dynamics calculations are performed at each time step in sequence to couple these effects in the code. To obtain more realistic magnetic field results for a given drive coil geometry, 2D and 3D effects are incorporated into the 1D field calculation through use of correction factor table lookup approach. Commercial low-frequency electromagnetic fields solver, ANSYS Maxwell 3D, is used to solve the magnetic field profile for static liner condition at various liner radius in order to derive correction factors for the 1D field calculation in the code. The liner dynamics results from the code is verified to be in good agreement with the results from commercial explicit dynamics solver, ANSYS Explicit Dynamics, and previous liner experiment. The developed code is used to optimize the capacitor bank and driver coil design for better energy transfer and coupling. FRC gain calculations are also performed using the liner compression data from the code for the conceptual design of the reactor sized system for fusion energy gains.

  3. Stability of Magnetically Implode Liners for High Energy Density Experiments

    SciTech Connect

    Reinovsky, R.E.; Anderson, W.E.; Atchison, W.L.; Bartsch, R.R.; Clark, D.A.; Ekdahl, C.E.; Faehl, R.J.; Goforth, J.H.; Keinigs, R.K.; Lindemuth, I.R.; Morgan, D.; Rodriguez, G.; Tasker, D.G.; Trainor, R.J.; Shlachter, J.S.

    1998-10-18

    Magnetically imploded cylindrical metal shells (z-pinch liners) are attractive drivers for a wide variety of hydrodynamics and material properties experiments. The ultimate utility of liners depends on the acceleration of near-solid density shells to velocities exceeding 20 km/sec with good azimuthal symmetry and axial uniformity. Two pulse power systems (Ranchero and Atlas) currently operational or under development at Los Alamos provide electrical energy adequate to accelerate {approximately}50 gr. liners to 1-2 MJ/cm kinetic energy. As in all z-pinches, the outer surface of a magnetically imploded liner is unstable to magneto-Rayleigh-Taylor (RT) modes during acceleration. Large-scale distortion in the liners from RT modes growing from glide plane interactions or initial imperfections could make liners unusable for man experiments. On the other hand, material strength in the liner should, from first principles, reduce the growth rate of RT modes - and can render some combinations of wavelength and amplitude analytically stable. The growth of instabilities in both soft aluminum liners and in high strength aluminum alloy liners has been studied analytically, computationally and experimentally at liner kinetic energies up to 100 KJ/cm on the Pegasus capacitor bank using driving currents up to 12 MA.

  4. Use of natural zeolites as a landfill liner.

    PubMed

    Tuncan, Ahmet; Tuncan, Mustafa; Koyuncu, Hakan; Guney, Yucel

    2003-02-01

    The purpose of this study is to investigate certain features of a novel material proposed to serve as an impervious liner in landfills. Various ratios of bentonites and zeolites (B/Z) compacted at optimum water content were tested to determine the strength parameters, permeability, pH, heavy metals and other properties. A B/Z ratio of 0.10 was found to be an ideal landfill liner material regarding its low hydraulic conductivity and high cation exchange capacity. The use of B/Z mixtures as an alternative to clay liners would provide potential to significantly reduce the thickness of base liner for landfills.

  5. Combustor liner cooling system

    DOEpatents

    Lacy, Benjamin Paul; Berkman, Mert Enis

    2013-08-06

    A combustor liner is disclosed. The combustor liner includes an upstream portion, a downstream end portion extending from the upstream portion along a generally longitudinal axis, and a cover layer associated with an inner surface of the downstream end portion. The downstream end portion includes the inner surface and an outer surface, the inner surface defining a plurality of microchannels. The downstream end portion further defines a plurality of passages extending between the inner surface and the outer surface. The plurality of microchannels are fluidly connected to the plurality of passages, and are configured to flow a cooling medium therethrough, cooling the combustor liner.

  6. Performance of semi-transportation-cooled liner in high-temperature-rise combustors

    NASA Technical Reports Server (NTRS)

    Wear, J. D.; Trout, A. M.; Smith, J. M.

    1981-01-01

    Results from tests with the Lamilloy combustor liner are compared with results obtained from a conventionally designed, film cooled, step-louver liner. Operation of the Lamilloy liner with counterrotating swirl combustor fuel modules with mixing venturis was possible to a fuel-air ratio of 0.065 without obtaining excessive liner metal temperatures. At the 0.065 fuel-air condition the average liner metal temperature was 140 K and the maximum local temperature 280 K above the inlet air temperature. Combustion efficiency, pattern factor, and smoke data are discussed.

  7. Attenuation of landfill leachate by clay liner materials in laboratory columns: 2. Behaviour of inorganic contaminants.

    PubMed

    Thornton, S F; Lerner, D N; Tellam, J H

    2001-02-01

    The chemical attenuation of inorganic contaminants in methanogenic landfill leachate, spiked with heavy metals (Cd, Cd, Ni and Zn), by two UK clay liner materials was compared in laboratory columns over 15 months. Ammonium was attenuated by ion-exchange but this attenuation was finite and when exhausted, NH4 passed through the liners at concentrations found in the leachate. The breakthrough behaviour of NH4 could be described by a simple distribution coefficient. Heavy metals were attenuated by sorption and precipitation of metal sulphide and carbonate compounds near the top of the liner. Adequate SO4 and CaCO3 in the liner is necessary to ensure the long term retention of heavy metals, and pH buffering agents added to stabilise reactive metal fractions should be admixed with the liner. Some metals may not be chemically attenuated by clay liners due to the formation of stable complexes with organic and/or colloidal fractions in leachate. Flushing of the liners with oxygenated water after leachate caused mobilisation of attenuated contaminants. Sorbed NH4 was released by the liners but groundwater loadings were manageable. Re-oxidation of metal sulphides under these conditions resulted in the release of heavy metals from the liners when the pH buffering capacity was poor. Contaminant attenuation by the clay liners was similar and the attenuation of NH4 and heavy metals could be predicted from the geochemical properties of the liner using simple tests. A conceptual model of clay liner performance is presented. Chemical attenuation of inorganic pollutants can be included in containment liner design to produce a dual reactive-passive barrier for landfills.

  8. Combustor liner durability analysis

    NASA Technical Reports Server (NTRS)

    Moreno, V.

    1981-01-01

    An 18 month combustor liner durability analysis program was conducted to evaluate the use of advanced three dimensional transient heat transfer and nonlinear stress-strain analyses for modeling the cyclic thermomechanical response of a simulated combustor liner specimen. Cyclic life prediction technology for creep/fatigue interaction is evaluated for a variety of state-of-the-art tools for crack initiation and propagation. The sensitivity of the initiation models to a change in the operating conditions is also assessed.

  9. Combustor liner support assembly

    NASA Technical Reports Server (NTRS)

    Halila, Ely E. (Inventor)

    1994-01-01

    A support assembly for a gas turbine engine combustor includes an annular frame having a plurality of circumferentially spaced apart tenons, and an annular combustor liner disposed coaxially with the frame and including a plurality of circumferentially spaced apart tenons circumferentially adjoining respective ones of the frame tenons for radially and tangentially supporting the liner to the frame while allowing unrestrained differential thermal radial movement therebetween.

  10. The Effect of Casting Ring Liner Length and Prewetting on the Marginal Adaptation and Dimensional Accuracy of Full Crown Castings

    PubMed Central

    Haralur, Satheesh B.; Hamdi, Osama A.; Al-Shahrani, Abdulaziz A.; Alhasaniah, Sultan

    2017-01-01

    Aim: To evaluate the effect of varying cellulose casting ring liner length and its prewetting on the marginal adaptation and dimensional accuracy of full veneer metal castings. Materials and Methods: The master die was milled in stainless steel to fabricate the wax pattern. Sixty wax patterns were fabricated with a uniform thickness of 1.5 mm at an occlusal surface and 1 mm axial surface, cervical width at 13.5 mm, and 10 mm cuspal height. The samples were divided into six groups (n = 10). Groups I and II samples had the full-length cellulose prewet and dry ring liner, respectively. The groups III and IV had 2 mm short prewet and dry cellulose ring liner, respectively, whereas groups V and VI were invested in 6 mm short ring liner. The wax patterns were immediately invested in phosphate bonded investment, and casting procedure was completed with nickel-chrome alloy. The castings were cleaned and mean score of measurements at four reference points for marginal adaption, casting height, and cervical width was calculated. The marginal adaption was calculated with Imaje J software, whereas the casting height and cervical width was determined using a digital scale. The data was subjected to one-way analysis of varaince and Tukey post hoc statistical analysis with Statistical Package for the Social Sciences version 20 software. Results: The group II had the best marginal adaption with a gap of 63.786 μm followed by group I (65.185 μm), group IV (87.740 μm), and group III (101.455 μm). A large marginal gap was observed in group V at 188.871 μm. Cuspal height was more accurate with group V (10.428 mm), group VI (10.421 mm), and group II (10.488 mm). The cervical width was approximately similar in group I, group III, and group V. Statistically significant difference was observed in Tukey post hoc analysis between group V and group VI with all the other groups with regards to marginal adaptation. Conclusion: The dry cellulose ring liners provided better marginal

  11. [Polyethylene liner replacement: behavior and morbidity in 68 cases].

    PubMed

    Bidar, R; Girard, J; May, O; Pinoit, Y; Laffargue, P; Migaud, H

    2007-09-01

    Isolated acetabular polyethylene exchange is advocated as an advantage of metal-backed cups, since the acetabular bone stock can be spared and operative time is shorter. The purpose of this study was to determine whether this is true. A consecutive serie of 68 THA revisions involving replacement of the polyethylene liner was analyzed retrospectively (liner replacement alone for 37 hips and liner replacement plus femoral component revision for 31). The posterolateral approach was used for the revision in all cases. This series was compared with a control series of revisions involving the acetabular component with revision of the femoral component in patients matched for age, sex, and BMI. Operative time and hospital stay were significantly shorter when the revision involved the polyethylene liner alone. In 19 hips, a limited zone of osteolysis was observed around the liner before replacement. At last follow-up, new zones of osteolysis were noted in two hips and aggravation in five, one of which required revision because of acetabular loosening. Episodes of dislocation were observed in nine hips (2 anterior and 7 posterior) of which three underwent revision because of recurrence. These dislocations occurred after liner replacement (n=4) or combined liner and femoral component replacement (n=5). Dislocations were more frequent after multiple hip operations and when the cup inclination was less than 40 degrees . Ten revisions were required for: an unclipped liner (n=2), recurrent dislocation (n=3), acetabular loosening (n=1), infection which was cured after a one-stage procedure (n=1). At seven years, survival was comparable between liner replacement alone (82+/-10%), combined liner replacement and femoral component revision (84+/-11%), and femoral component and acetabular component revision (82+/-11%). Changing the cup liner can limit morbidity compared with a more complex revision, but liner replacement alone is insufficient in the event of acetabular osteolysis. It

  12. Turbulator for a liner cooling jacket

    NASA Technical Reports Server (NTRS)

    Hoag, Kevin L. (Inventor)

    1995-01-01

    A turbulator for a liner cooling jacket includes a metal panel which is suitable to be coiled into a generally cylindrical shape so as to be placed in a relief area between an engine cylinder block and a cylinder liner. The relief area may be machined into either the block or the cylinder liner and the metal panel is formed with a pattern of protuberances shaped like corrugations. In one embodiment, the corrugations have a shape similar to a sine wave and are arranged in a plurality of generally parallel axial segments. The corrugation wave pattern of one segment may be the same as its adjacent segment or may be staggered by one corrugation which would mean one-half of a full wave cycle. The corrugation pattern in the turbulator panel may be created by any one of various stamping or forming operations and when placed between the cylinder liner and block, increases turbulence of the cooling liquid in order to enhance heat transfer.

  13. Three LINERs Under the Hubble Spectral Microscope

    NASA Astrophysics Data System (ADS)

    Molina, Mallory; Eracleous, Michael; Barth, Aaron J.; Maoz, Dan; Walsh, Jonelle; Ho, Luis C.; Shields, Joseph C.

    2016-01-01

    The majority of low-ionization nuclear emission regions (LINERs) harbor supermassive black holes (SMBHs) with very low accretion rates. Since SMBHs spend most of their lifetimes in these low accretion-rate states, understanding LINERs is important for understanding active galactic nuclei (AGN) in the context of galaxy evolution. On scales of ~100 pc, the energy budget of LINERs appears to be deficient when the only source of power considered is the AGN. Thus, other energy sources are likely to contribute to the excitation of the emission-line gas. To probe these sources, we observed three nearby, bright, and representative LINERs with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST). We specifically looked at the 0.1-1 arcsecond scale (corresponding to ~5-50 pc) to find what these energy sources are and how far from the nucleus they take over the excitation of the gas. After subtracting both the unresolved nuclear light and the spatially-extended starlight, we measured a number of diagnostic emission line ratios. We find that within 10 pc, the observed line ratios of [O III]/[O II] vs [O IIII]/H-beta are consistent with AGN photoionization. The line ratios of [N II]/H-alpha vs [O III]/H-beta show that at larger distances, the excitation mechanism is most likely consistent with hot stars or shocks. Shocks are particularly appealing in the case of NGC 4278, which harbors a Gigahetz-Peaked radio source with small jets detected by the VLBA. If hot stars are the primary excitation mechanism, these are most likely post-AGB stars (from the old stellar population). We conclude from these representative cases that the characteristic LINER emission-line spectrum does not result from a single excitation mechanism, but rather from a combination of different mechanisms within the central 100 pc of each object that varies from object to object.

  14. Acoustic Liners for Turbine Engines

    NASA Technical Reports Server (NTRS)

    Jones, Michael G (Inventor); Grady, Joseph E (Inventor); Kiser, James D. (Inventor); Miller, Christopher (Inventor); Heidmann, James D. (Inventor)

    2016-01-01

    An improved acoustic liner for turbine engines is disclosed. The acoustic liner may include a straight cell section including a plurality of cells with straight chambers. The acoustic liner may also include a bent cell section including one or more cells that are bent to extend chamber length without increasing the overall height of the acoustic liner by the entire chamber length. In some cases, holes are placed between cell chambers in addition to bending the cells, or instead of bending the cells.

  15. REVERSIBLE METAL-TO-METAL METHYL TRANSFER IN n5-CYCLOPENTADIENYL(TRIPHENYLPHOSPHINE)DIMETHYLCOBALT(III)

    SciTech Connect

    Bryndza, Henry E.; Evitt, Eric R.; Bergman, Robert G.

    1980-05-01

    Labeling techniques have been used to demonstrate that {eta}{sup 5} cyclopentadienyl(triphenylphosphine)dimethylcobalt(III) (1) undergoes intermolecular cobalt-to-cobalt methyl group exchange. The reaction follows second order kinetics; rate constants for methyl exchange between complexes 1 and its methylcyclopentadienyl analog 4 show decreasing magnitude with increasing bulk of cyclopentadienyl substituents. Studies of the reaction with excess triphenylphosphine and complexes labeled with the non-dissociating trimethylphosphine ligand indicate the reaction requires dissociation of phosphine from one of the two partners in the exchange before scrambling can take place. Further studies with other complexes (e.g., Cp{sub 2}Zr(CH{sub 3}){sub 2}) suggest that alkyl exchange between two transition metal centers may be a more general reaction than has heretofore been suspected.

  16. Heavy metal tolerance of Fe(III)-reducing microbial communities in contaminated creek bank soils.

    PubMed

    Burkhardt, Eva-Maria; Bischoff, Sebastian; Akob, Denise M; Büchel, Georg; Küsel, Kirsten

    2011-05-01

    Fe(III)-reducing soil enrichment cultures can tolerate 100 μM Cu and Cd, 150 μM Co, 600 μM Ni, and 2,500 μM Zn. Metal-tolerant cultures were dominated by Geobacter-related Deltaproteobacteria and Gram-positive Firmicutes spp. (Clostridia and Sedimentibacter). A Cd- and Cu-tolerant Fe(III)-reducing coculture of Desulfosporosinus and Desulfitobacterium indicated the importance of the Firmicutes for Fe(III) reduction in the presence of metals.

  17. Composite heat pipe development status: Development of lightweight prototype carbon-carbon heat pipe with integral fins and metal foil liner

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Rovang, Richard D.

    1995-01-01

    This report discusses development and proof-of-concept testing of a new lightweight carbon-carbon (C-C) space radiator heat pipe, carried out under the NASA Civil Space Technology Initiative (CSTI) High Capacity Power Program. The prototype heat pipe, equipped with a niobium-zirconium foil liner, was filled with potassium working fluid and tested for 11 hours, including startup from ambient temperature with the working fluid initially in the frozen state to near 700 K condenser temperature. Steady-state heat pipe input power during testing was facility limited to about 300 watts. Post test inspection showed the heat pipe to be in excellent condition after eight thermal cycles from ambient to steady-state operating temperature. Utilization of other liner materials and working fluids would greatly extend the spectrum of service temperatures for this technology, with potential applications ranging from small spacecraft heat rejection to aircraft and terrestrial uses.

  18. Development of composite pressure vessels with nonmetallic liners

    NASA Astrophysics Data System (ADS)

    Murray, Con F.; Newhouse, Norman L.; Schimenti, John D.; Tiller, Dale B.

    1992-07-01

    Brunswick composites has developed metallic liners and composite cylinders for use in military and civilian aircraft, missiles, inflation systems and space applications. At present an all-composite pressurant tank is being developed for use in the natural gas vehicle (NGV). This tank uses a plastic liner of high density polyethylene (HDPE) as a leak-tight permeation barrier. Tank characteristics and testing are described. HDPE reduces cost, meets all space and missile pressurant tank requirements, and is readily availble. Test results indicate that an all-composite pressurant tank with an HDPE liner provides a tough, high cycle life, lightweight, environmentally stable pressurant tank with very low permeability. HDPE offers a viable, low cost alternative to conventional metal liners as well as many design advantages.

  19. Long-Term Outcomes of Liner Cementation into a Stable Retained Shell: A Concise Follow-up of a Previous Report.

    PubMed

    Tan, Timothy L; Le Duff, Michel J; Ebramzadeh, Edward; Bhaurla, Sandeep K; Amstutz, Harlan C

    2015-06-03

    Liner cementation into a preexisting stable socket may reduce the morbidity of revision hip arthroplasty and preserve acetabular bone. However, the long-term outcomes of this technique remain unknown. The purpose of this report was to analyze the long-term results of a previously reported cohort of patients. Cementation of thirty-two liners (seventeen polyethylene and fifteen metal liners) into preexisting sockets was performed during revision hip arthroplasty, and the patients were followed for a minimum of two years. A retrospective chart review was performed to investigate the complications and survivorship. The mean duration of follow-up was 12.7 years (range, 2.1 to 19.1 years), with ten hips requiring rerevision at a mean of 6.4 years (range, 1.0 to 15.5 years). Nine patients experienced posterior dislocations, and two hips required rerevision for instability. Liner dissociation from the shell occurred in two patients. Survivorship analysis, with rerevision as the end point, demonstrated ten and fifteen-year survivorship of 77.3% and 68.8%, respectively. Dissociation of the cemented liner from the acetabular shell was an infrequent cause of failure despite long-term follow-up. Given the high rate of dislocations in this study, careful patient selection and surgical technique should be considered. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

  20. Metallicity of the Intergalactic Medium Using Pixel Statistics. III. Silicon

    NASA Astrophysics Data System (ADS)

    Aguirre, Anthony; Schaye, Joop; Kim, Tae-Sun; Theuns, Tom; Rauch, Michael; Sargent, Wallace L. W.

    2004-02-01

    We study the abundance of silicon in the intergalactic medium by analyzing the statistics of Si IV, C IV, and H I pixel optical depths in a sample of 19 high-quality quasar absorption spectra, which we compare with realistic spectra drawn from a hydrodynamical simulation. Simulations with a constant and uniform Si/C ratio, a C distribution as derived in Paper II of this series, and a UV background (UVB) model from Haardt & Madau reproduce the observed trends in the ratio of Si IV and C IV optical depths, τSiIV/τCIV. The ratio τSiIV/τCIV depends strongly on τCIV, but it is nearly independent of redshift for fixed τCIV and is inconsistent with a sharp change in the hardness of the UVB at z~3. Scaling the simulated optical depth ratios gives a measurement of the global Si/C ratio (using our fiducial UVB, which includes both galaxy and quasar contributions) of [Si/C]=0.77+/-0.05, with a possible systematic error of ~0.1 dex. The inferred [Si/C] depends on the shape of the UVB (harder backgrounds leading to higher [Si/C]), ranging from [Si/C]~=1.5 for a quasar-only UVB to [Si/C]~=0.25 for a UVB including both galaxies and artificial softening; this provides the dominant uncertainty in the overall [Si/C]. Examination of the full τSiIV/τCIV distribution yields no evidence for inhomogeneity in [Si/C] and constrains the width of a lognormal probability distribution in [Si/C] to be much smaller than that of [C/H]; this implies a common origin for Si and C. Since the inferred [Si/C] depends on the UVB shape, this also suggests that inhomogeneities in the hardness of the UVB are small. There is no evidence for evolution in [Si/C]. Variation in the inferred [Si/C] with density depends on the UVB and rules out the quasar-only model unless [Si/C] increases sharply at low density. Comparisons with low-metallicity halo stars and nucleosynthetic yields suggest either that our fiducial UVB is too hard or that supermassive Population III stars might have to be included. The

  1. One-Liners

    ERIC Educational Resources Information Center

    Hathaway, Nan

    2008-01-01

    This article describes an exercise appropriate for all grade levels. This exercise is based on a book of Picasso's contour drawings called "Picasso's One-Liners," which combines a delightful assortment of one-line drawings with accompanying one-line quotes. Students are given a stack of copy paper and a black fine-tip marker. Students then take…

  2. One-Liners

    ERIC Educational Resources Information Center

    Hathaway, Nan

    2008-01-01

    This article describes an exercise appropriate for all grade levels. This exercise is based on a book of Picasso's contour drawings called "Picasso's One-Liners," which combines a delightful assortment of one-line drawings with accompanying one-line quotes. Students are given a stack of copy paper and a black fine-tip marker. Students then take…

  3. On the metallicity of open clusters. III. Homogenised sample

    NASA Astrophysics Data System (ADS)

    Netopil, M.; Paunzen, E.; Heiter, U.; Soubiran, C.

    2016-01-01

    Context. Open clusters are known as excellent tools for various topics in Galactic research. For example, they allow accurately tracing the chemical structure of the Galactic disc. However, the metallicity is known only for a rather low percentage of the open cluster population, and these values are based on a variety of methods and data. Therefore, a large and homogeneous sample is highly desirable. Aims: In the third part of our series we compile a large sample of homogenised open cluster metallicities using a wide variety of different sources. These data and a sample of Cepheids are used to investigate the radial metallicity gradient, age effects, and to test current models. Methods: We used photometric and spectroscopic data to derive cluster metallicities. The different sources were checked and tested for possible offsets and correlations. Results: In total, metallicities for 172 open cluster were derived. We used the spectroscopic data of 100 objects for a study of the radial metallicity distribution and the age-metallicity relation. We found a possible increase of metallicity with age, which, if confirmed, would provide observational evidence for radial migration. Although a statistical significance is given, more studies are certainly needed to exclude selection effects, for example. The comparison of open clusters and Cepheids with recent Galactic models agrees well in general. However, the models do not reproduce the flat gradient of the open clusters in the outer disc. Thus, the effect of radial migration is either underestimated in the models, or an additional mechanism is at work. Conclusions: Apart from the Cepheids, open clusters are the best tracers for metallicity over large Galactocentric distances in the Milky Way. For a sound statistical analysis, a sufficiently large and homogeneous sample of cluster metallicities is needed. Our compilation is currently by far the largest and provides the basis for several basic studies such as the statistical

  4. Solubilization of Fe(III) oxide-bound trace metals by a dissimilatory Fe(III) reducing bacterium

    NASA Astrophysics Data System (ADS)

    Zachara, John M.; Fredrickson, Jim K.; Smith, Steven C.; Gassman, Paul L.

    2001-01-01

    Trace metals associate with Fe(III) oxides as adsorbed or coprecipitated species, and consequently, the biogeochemical cycles of iron and the trace metals are closely linked. This communication investigated the solubilization of coprecipitated Co(III) and Ni(II) from goethite (α-FeOOH) during dissimilatory bacterial iron reduction to provide insights on biogeochemical factors controlling trace-element fluxes in anoxic environments. Suspensions of homogeneously substituted Co-FeOOH (50 mmol/L as Co 0.01Fe 0.99OOH; 57Co-labeled) in eight different buffer/media solutions were inoculated with a facultative, metal-reducing bacteria isolated from groundwater ( Shewanella putrefacians CN32), and incubated under strictly anaerobic conditions for periods up to 32 days. Lactate (30 mmol/L) was provided as an electron donor. Growth and non-growth promoting conditions were established by adding or withholding PO 4 and/or trace metals ( 60Co-labeled) from the incubation media. Anthraquinone disulfonate (AQDS; 100 μmol/L) was added to most suspensions as an electron shuttle to enhance bacterial reduction. Solutions were buffered at circumneutral pH with either PIPES or bicarbonate buffers. Solid and liquid samples were analyzed at intermediate and final time points for aqueous and sorbed/precipitated (by HCl extraction) Fe(II) and Co(II). The bioreduced solids were analyzed by X-ray diffraction and field-emission electron microscopy at experiment termination. Ni-FeOOH (Ni 0.01Fe 0.99OOH) was used for comparison in select experiments. Up to 45% of the metal containing FeOOH was bioreduced; growth-supporting conditions did not enhance reduction. The biogenic Fe(II) strongly associated with the residual Fe(III) oxide as an undefined sorbed phase at low fractional reduction in PIPES buffer, and as siderite (FeCO 3) in bicarbonate buffer or as vivianite [Fe 3(PO 4) 2 · 8H 2O] when P was present. Cobalt(III) was reduced to Co(II) in proportion to its mole ratio in the solid. The

  5. Configuration Effects on Liner Performance

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Brown, Martha C.; Jones, Michael G.; Howerton, Brian M.

    2012-01-01

    The acoustic performance of a duct liner depends not only on the intrinsic properties of the liner but also on the configuration of the duct in which it is used. A series of experiments is performed in the NASA Langley Research Center Curved Duct Test Rig (at Mach 0.275) to evaluate the effect of duct configuration on the acoustic performance of single degree of freedom perforate-over-honeycomb liners. The liners form the sidewalls of the duct's test section. Variations of duct configuration include: asymmetric (liner on one side and hard wall opposite) and symmetric (liner on both sides) wall treatment; inlet and exhaust orientation, in which the sound propagates either against or with the flow; and straight and curved flow path. The effect that duct configuration has on the overall acoustic performance, particularly the shift in frequency and magnitude of peak attenuation, is quantified. The redistribution of incident mode content is shown. The liners constitute the side walls of the liner test section and the scatter of incident horizontal order 1 mode by the asymmetric treatment and order 2 mode by the symmetric treatment into order 0 mode is shown. Scatter of order 0 incident modes into higher order modes is also shown. This redistribution of mode content is significant because it indicates that the liner design can be manipulated such that energy is scattered into more highly attenuated modes, thus enhancing liner performance.

  6. Well liner running shoe

    SciTech Connect

    Bell, J.F.

    1994-01-11

    Wellbore liners are set with a running shoe comprising a cylindrical body, end cap, check valve and receiver member in assembly. The receiver member includes threads for receiving the coupling sleeve of a running tool, and retaining wickers for engagement with a cement plug or dart to retain the same permanently engaged with and blocking the flow of fluid through the running shoe. A running tool for use with the shoe includes a coupling sleeve which is retained on a support mandrel by a collar which is secured to the mandrel with a shear pin so that pressuring up the workstring, in the event of a stuck coupling sleeve, will permit retrieval of the main part of the running tool and the workstring. The interior parts of the running shoe are made of aluminum or plastic for easy drill-out to extend the wellbore beyond the end of the liner. 3 figs.

  7. Microsecond ramp compression of a metallic liner driven by a 5 MA current on the SPHINX machine using a dynamic load current multiplier pulse shaping

    SciTech Connect

    D'Almeida, T.; Lassalle, F.; Morell, A.; Grunenwald, J.; Zucchini, F.; Loyen, A.; Maysonnave, T.; Chuvatin, A. S.

    2013-09-15

    SPHINX is a 6 MA, 1-μs Linear Transformer Driver (LTD) operated by the CEA Gramat (France) and primarily used for imploding Z-pinch loads for radiation effects studies. Among the options that are currently being evaluated to improve the generator performances are an upgrade to a 20 MA, 1-μs LTD machine and various power amplification schemes, including a compact Dynamic Load Current Multiplier (DLCM). A method for performing magnetic ramp compression experiments, without modifying the generator operation scheme, was developed using the DLCM to shape the initial current pulse in order to obtain the desired load current profile. In this paper, we discuss the overall configuration that was selected for these experiments, including the choice of a coaxial cylindrical geometry for the load and its return current electrode. We present both 3-D Magneto-hydrodynamic and 1D Lagrangian hydrodynamic simulations which helped guide the design of the experimental configuration. Initial results obtained over a set of experiments on an aluminium cylindrical liner, ramp-compressed to a peak pressure of 23 GPa, are presented and analyzed. Details of the electrical and laser Doppler interferometer setups used to monitor and diagnose the ramp compression experiments are provided. In particular, the configuration used to field both homodyne and heterodyne velocimetry diagnostics in the reduced access available within the liner's interior is described. Current profiles measured at various critical locations across the system, particularly the load current, enabled a comprehensive tracking of the current circulation and demonstrate adequate pulse shaping by the DLCM. The liner inner free surface velocity measurements obtained from the heterodyne velocimeter agree with the hydrocode results obtained using the measured load current as the input. An extensive hydrodynamic analysis is carried out to examine information such as pressure and particle velocity history profiles or magnetic

  8. Microsecond ramp compression of a metallic liner driven by a 5 MA current on the SPHINX machine using a dynamic load current multiplier pulse shaping

    NASA Astrophysics Data System (ADS)

    d'Almeida, T.; Lassalle, F.; Morell, A.; Grunenwald, J.; Zucchini, F.; Loyen, A.; Maysonnave, T.; Chuvatin, A. S.

    2013-09-01

    SPHINX is a 6 MA, 1-μs Linear Transformer Driver (LTD) operated by the CEA Gramat (France) and primarily used for imploding Z-pinch loads for radiation effects studies. Among the options that are currently being evaluated to improve the generator performances are an upgrade to a 20 MA, 1-μs LTD machine and various power amplification schemes, including a compact Dynamic Load Current Multiplier (DLCM). A method for performing magnetic ramp compression experiments, without modifying the generator operation scheme, was developed using the DLCM to shape the initial current pulse in order to obtain the desired load current profile. In this paper, we discuss the overall configuration that was selected for these experiments, including the choice of a coaxial cylindrical geometry for the load and its return current electrode. We present both 3-D Magneto-hydrodynamic and 1D Lagrangian hydrodynamic simulations which helped guide the design of the experimental configuration. Initial results obtained over a set of experiments on an aluminium cylindrical liner, ramp-compressed to a peak pressure of 23 GPa, are presented and analyzed. Details of the electrical and laser Doppler interferometer setups used to monitor and diagnose the ramp compression experiments are provided. In particular, the configuration used to field both homodyne and heterodyne velocimetry diagnostics in the reduced access available within the liner's interior is described. Current profiles measured at various critical locations across the system, particularly the load current, enabled a comprehensive tracking of the current circulation and demonstrate adequate pulse shaping by the DLCM. The liner inner free surface velocity measurements obtained from the heterodyne velocimeter agree with the hydrocode results obtained using the measured load current as the input. An extensive hydrodynamic analysis is carried out to examine information such as pressure and particle velocity history profiles or magnetic

  9. Highly Efficient Cooperative Catalysis by Co(III) (Porphyrin) Pairs in Interpenetrating Metal-Organic Frameworks.

    PubMed

    Lin, Zekai; Zhang, Zhi-Ming; Chen, Yu-Sheng; Lin, Wenbin

    2016-10-24

    A series of porous twofold interpenetrated In-Co(III) (porphyrin) metal-organic frameworks (MOFs) were constructed by in situ metalation of porphyrin bridging ligands and used as efficient cooperative catalysts for the hydration of terminal alkynes. The twofold interpenetrating structure brings adjacent Co(III) (porphyrins) in the two networks parallel to each other with a distance of about 8.8 Å, an ideal distance for the simultaneous activation of both substrates in alkyne hydration reactions. As a result, the In-Co(III) (porphyrin) MOFs exhibit much higher (up to 38 times) catalytic activity than either homogeneous catalysts or MOF controls with isolated Co(III) (porphyrin) centers, thus highlighting the potential application of MOFs in cooperative catalysis. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Double shell liner implosions

    SciTech Connect

    Sorokin, S. A.; Chaikovsky, S. A.

    1997-05-05

    Experiments on the double shell liner (DSL) implosions with and without an initial axial magnetic were performed on the SNOP-3 pulse generator (1.1 MA, 100 ns). In implosions of a DSL without an initial axial magnetic field, high radial compressions of the inner shell were observed, as in previous experiments with an initial axial magnetic field. Possible mechanisms for the formation of the initial azimuthal magnetic field are discussed.

  11. Study of Liner Collapse, Jet Formation and Characteristics from Implosive Shaped Charge Systems

    DTIC Science & Technology

    1977-11-01

    later. Figure 14 shows a plot of the velocity versus time for ten different tracer particles placed on the inside surface of the hemispherical liner...while figures 15 through 17 show plots of velocities versus time of four particles placed across the liner thickness at three different locations, one on...experimental data. Figure 18 shows a plot of the average velocity components of the metallic liner as a function of time, while Figure 19 shows the different

  12. Liner protected carbon-carbon heat pipe concept

    NASA Astrophysics Data System (ADS)

    Rovang, Richard D.; Hunt, Maribeth E.

    1992-01-01

    A lightweight, high performance radiator concept using carbon-carbon heat pipes is being developed to support space nuclear power applications, specifically the SP-100 system. Carbon-carbon has been selected as an outer structural tube member because of its high temperature and strength characteristics; however, this material must be protected from the potassium heat pipe working fluid. A metallic liner approach is being taken to provide this fluid barrier. Feasibility issues associated with this approach include materials compatibility, fabricastion of the thin-walled liner, bonding the liner to the carbon-carbon tube, mismatch of coefficient of thermal expansion (CTE), carbon diffusion, and end cap closures. To resolve these issues, a series of test coupons have been fabricated and tested, assessing various liner materials, braze alloys, and substrate precursors. These tests will lead to a final heat pipe architecture, material selection, and component assembly.

  13. The evolution of galaxies. III - Metal-enhanced star formation

    NASA Technical Reports Server (NTRS)

    Talbot, R. J., Jr.; Arnett, W. D.

    1973-01-01

    The problem of the paucity of low-metal-abundance low-mass stars is discussed. One alternative to the variable-initial-mass-function (VIMF) solution is proposed. It is shown that this solution - metal-enhanced star formation - satisfies the classical test which prompted the VIMF hypothesis. Furthermore, with no additional parameters it provides improved fits to other tests - e.g., inhomogeneities in the abundances in young stars, concordance of all nucleo-cosmochronologies, and a required yield of heavy-element production which is consistent with current stellar evolution theory. In this model the age of the Galaxy is 18.6 plus or minus 5.7 b.y.

  14. The evolution of galaxies. III - Metal-enhanced star formation

    NASA Technical Reports Server (NTRS)

    Talbot, R. J., Jr.; Arnett, W. D.

    1973-01-01

    The problem of the paucity of low-metal-abundance low-mass stars is discussed. One alternative to the variable-initial-mass-function (VIMF) solution is proposed. It is shown that this solution - metal-enhanced star formation - satisfies the classical test which prompted the VIMF hypothesis. Furthermore, with no additional parameters it provides improved fits to other tests - e.g., inhomogeneities in the abundances in young stars, concordance of all nucleo-cosmochronologies, and a required yield of heavy-element production which is consistent with current stellar evolution theory. In this model the age of the Galaxy is 18.6 plus or minus 5.7 b.y.

  15. X-ray sources such as metallic liner inside plastic cavities are used to test atomic physics models for LMJ simulations

    NASA Astrophysics Data System (ADS)

    Girard, Frederic; Jacquet, L.; Primout, M.; Babonneau, D.; Villette, B.; Stemmler, Ph.

    2009-11-01

    Bright multi-keV K-shell emission sources [1-3] are necessary for ICF studies such as radiography of dense materials. Our recent works with titanium (Heα at 4.7 keV) and germanium (Heα at 10.3 keV) lined cavities showed very high multi-keV x-ray conversion efficiencies up to 14.0% and 0.8% (respectively) [3]. Cavities with a titanium, copper or germanium liner have been used on the OMEGA laser facility in Rochester to test specifically atomic physics models coupled to hydrodynamic codes. Simulation results differ significantly from experimental conversion efficiencies for titanium liner but they are close together for germanium one. Atomic physics models do have great impact on X-ray output. The need for accurate predictive simulation is important in order to set up relevant radiography sources for experiments on the path to ignition. Multi-keV emission is diagnosed by a full set of diagnostics giving conversion efficiencies, time dependant x-ray power and imaging, time integrated imaging and high resolution spectra of titanium. [4pt] [1] D. Babonneau et al., Phys. Plasmas, 15, 092702, 2008 [0pt] [2] K. B. Fournier et al., Phys. Plasmas, 16 052703, 2009 [0pt] [3] F. Girard et al., Phys. Plasmas, 16, 052704, 2009

  16. Infrared spectra of group III A metal oxides

    NASA Technical Reports Server (NTRS)

    Lynch, D. A., Jr.

    1972-01-01

    The measurement of infrared frequencies of metal-oxygen species which could be formed in the matrix and to investigate with an oxygen-18 enrichment study the controversy on the vibrational assignments for the suboxide. Several new molecules, Al3O2, Ga3O, In3O, In4O2, IntaO, IntaO2, and In2WO4, were found by mass spectrometric sampling to exist in extremely minor concentrations in the vapor phase. The latter three species were formed by reaction with the crucible materials and were unimportant for an infrared analysis. The infrared spectroscopic measurements were obtained by the matrix isolation technique of molecular beam sampling. The MO2 species were formed by direct reaction between metal and O2 in the matrix. A C2v structure and an O-M-O bond angle near 40 deg was favored for these molecules by analogy with a similar investigation of the alkali metals. The vibrational frequencies which were determined are given.

  17. Preparations to ship EPICOR liners

    SciTech Connect

    Queen, S P

    1983-06-01

    The sampling and analysis of the hydrogen rich atmosphere of the 49 EPICOR II ion-exchange prefilter liners generated in the decontamination of radioactive water at TMI-2 will provide data to ensure safe storage and shipment of highly loaded ion-exchange media. This report discusses the prototype gas sampling tool used to breech the containment of the liners, the tool support equipment for sampling and inerting the liners, and the characterization program used for determining the radiolytic hydrogen generation rates in the liners.

  18. Metallosis after Exchange of the Femoral Head and Liner following Ceramic Acetabular Liner Dissociation in Total Hip Arthroplasty with a Modular Layered Acetabular Component

    PubMed Central

    Hamada, Daisuke; Iwame, Toshiyuki; Sairyo, Koichi

    2016-01-01

    The type of bearing material that should be used in revision surgery after the failure of ceramic-on-ceramic total hip arthroplasty (THA) remains controversial. In the case of ceramic fracture, the residual ceramic particles can cause consequent metallosis when metal implants are used for revision THA. On the other hand, in the case of THA failure without ceramic fracture, revision THA with a metal femoral head provides satisfactory results. We report an unusual case of progressive osteolysis due to metallosis that developed after revision THA for ceramic liner dissociation without a liner fracture performed using a metal femoral head and polyethylene liner. The residual metal debris and abnormal pumping motion of the polyethylene liner due to the breakage of the locking system or the aspherical metal shell being abraded by the ceramic head seemed to be the cause of the progressive osteolysis. PMID:27648325

  19. Dissolution of iron(III)(HYDR)oxides by metal-EDTA-complexes

    SciTech Connect

    Nowack, B.; Sigg, L.

    1996-10-01

    The dissolution of Fe(III)(hydroxides) (goethite and hydrous ferric oxide) by metal-EDTA complexes occurs by ligand-promoted dissolution. The process is initiated by adsorption of the metal-EDTA to the surface, dissociation of the complex at the surface and release of Fe(III)EDTA into solution. The dissolution rate is decreased to a great extent if EDTA is complexed by metals in comparison to uncomplexed EDTA. The rate decreases in the order EDTA >> CaEDTA > PbEDTA > ZnEDTA > CuEDTA > Co(II)EDTA > NiEDTA. Two different rate-limiting steps determine the system: (1) detachment of Fe(III) from the oxide-structure and (2) dissociation of the metal-EDTA complexes. In the case of goethite, step (1) is more important than (2) and the difference in the dissolution rate for several metals is small. In the case of hydrous ferric oxide, step (2) is rate-limiting and the effect of the complexed metal is very pronounced.

  20. Dissolution of Fe(III)(hydr) oxides by metal-EDTA complexes

    SciTech Connect

    Nowack, B.; Sigg, L. |

    1997-03-01

    The dissolution of Fe(III)(hydr)oxides (goethite and hydrous ferric oxide) by metal-EDTA complexes occurs by ligand-promoted dissolution. The process is initiated by the adsorption of metal-EDTA complexes to the surface and is followed by the dissociation of the complex at the surface and the release of Fe(III)EDTA into solution. The dissolution rate is decreased to a great extent if EDTA is complexed by metals in comparison to the uncomplexed EDTA. The rate decreases in the order EDTA > CaEDTA > PbEDTA > ZnEDTA > CuEDTA > Co(II)EDTA > NiEDTA. Two different rate-limiting steps determine the dissolution process: (1) detachment of Fe(III) from the oxide-structure and (2) dissociation of the metal-EDTA complexes. In the case of goethite, step 1 is slower than step 2 and the dissolution rates by various metals are similar. In the case of hydrous ferric oxide, step 2 is rate-limiting and the effect of the complexed metal is very pronounced. 35 refs., 11 figs., 4 tabs.

  1. Energy transfer between terbium (III) and cobalt (II) in thermolysin: a new class of metal--metal distance probes.

    PubMed Central

    Horrocks, W D; Holmquist, B; Vallee, B L

    1975-01-01

    The visible fluorescence of terbium(III) when bound to a calcium binding site of thermolysin is greatly enhanced with an excitation maximum at 280 nm but substitution of cobalt(II) for zinc at the active site decreases the intensity by 89.5%. Treatment with N-bromosuccinimide quenches enzyme tryptophan and Tb(III) fluorescence to a similar extent and suggests the operation of tryptophan vector Tb(III) vector Co(II) energy relay system in the enzyme. Dipoledipole radiationless energy transfer between the Tb(III) donor and the Co(II) acceptor can account for this quenching. The inherent characteristics of the metal pair limits the value of the orientation factor, K2, of the Förster equation, thereby reducing uncertainties in distance measurements by energy transfer compared with other systems. A quantum yield of 0.51 yields a value of R0, the distance for 50% energy transfer, of 19.6 A, and a distance, R, between Tb(III) and Co(II) of 13.7 A, a value identical to that measured for the distance between the active site zinc atom and calcium atom number 1 by x-ray analysis in native thermolysin crystals. The limits of confidence of this measurement are discussed. Energy transfer between two different metal atom sites of a protein provides a new class of probes to measure intramolecular distances of biological macromolecules in solution. PMID:1061067

  2. Does cation dehydration drive the binding of metal ions to polyelectrolytes in water? What we can learn from the behaviour of aluminium(III) and chromium(III).

    PubMed

    Burrows, Hugh D; Costa, Diana; Ramos, M Luísa; Miguel, M da Graça; Teixeira, M Helena; Pais, Alberto A C C; Valente, Artur J M; Bastos, Margarida; Bai, Guangyue

    2012-06-14

    Much stronger binding is seen in aqueous solutions between the anionic polyelectrolyte potassium poly(vinyl sulfate) and the substitution labile aluminium(III) than with the kinetically inert chromium(III). This strongly supports the idea that entropy driven water loss from the hydration sphere of the metal ion plays a major role in driving binding of the trivalent metal ion to the polyelectrolyte.

  3. Unveiling the liner nature of NGC1052

    NASA Astrophysics Data System (ADS)

    Diniz, S. I. F.; Pastoriza, M. G.; Riffel, R.; Riffel, R. A.; Diniz, M. R.; Storchi-Bergmann, T.

    2014-10-01

    NGC 1052 is an E4 galaxy and classified as a typical LINER harboring a stellar rotating disk. However, the central region is spectroscopically unusual with broad optical emission lines, the nature of its emission line gas remains unclear. According to recent studies NGC 1052 exhibit Hα luminosities an order of magnitude above that estimated for an evolved population of extreme horizontal branch stars. Their Hα equivalent widths and optical-to-near infrared (NIR) spectral energy distributions are consistent with them being young stellar clusters aged < 7 Myr, and according to previous works, NGC 1052 may have experienced a merger event about 1 Gyr ago. There are mainly three possibilities to explain LINER's spectra: i) post asymptotic giant branch stars (post-AGB) that ionize their rapidly expanding shells, (ii) active galactic nuclei (AGNs) powered by the in fall of matter into an accretion disk, and (iii) shocks. The stellar population (SP) of AGNs shows an excess of intermediate age stars. Besides, NIR stellar population studies have revealed that the continuum of active galaxies is dominated by the contribution of intermediate age stellar populations. Hot dust emission unresolved is also commonly detected in NIR nuclear spectra of galaxies Seyfert and LINERs. Aimed to discriminate the dominant ionizing source of NGC 1052 we present preliminary results of high spatial resolution integral field spectroscopy, taken with gemini NIFS to map the dominant stellar population, as well as disentangling the featureless and hot dust components.

  4. Energy efficient engine pin fin and ceramic composite segmented liner combustor sector rig test report

    NASA Technical Reports Server (NTRS)

    Dubiel, D. J.; Lohmann, R. P.; Tanrikut, S.; Morris, P. M.

    1986-01-01

    Under the NASA-sponsored Energy Efficient Engine program, Pratt and Whitney has successfully completed a comprehensive test program using a 90-degree sector combustor rig that featured an advanced two-stage combustor with a succession of advanced segmented liners. Building on the successful characteristics of the first generation counter-parallel Finwall cooled segmented liner, design features of an improved performance metallic segmented liner were substantiated through representative high pressure and temperature testing in a combustor atmosphere. This second generation liner was substantially lighter and lower in cost than the predecessor configuration. The final test in this series provided an evaluation of ceramic composite liner segments in a representative combustor environment. It was demonstrated that the unique properties of ceramic composites, low density, high fracture toughness, and thermal fatigue resistance can be advantageously exploited in high temperature components. Overall, this Combustor Section Rig Test program has provided a firm basis for the design of advanced combustor liners.

  5. LINER FOR EXTRUSION BILLET CONTAINERS

    DTIC Science & Technology

    Rokide-process alumina and zirconia coatings and a Udimet 700 superalloy liner were evaluated by extrusion of 3 1/2-in. billets of Inconel 713C...One coating did with stand extrusion at 3450 F without apparent wear. The Udimet 700 liner did not show wear at 2000 F, but did react with the TZM

  6. How to select an effective waste pit liner

    SciTech Connect

    Hinds, A.A.; Legget, L.H.; Liao, A.

    1987-01-01

    This article reports that the use of earthen pits is widespread in the oil and gas industry. These pits are used to contain produced water as well as waste fluids and solids from drilling activities. The pits contain a myriad of metals, salts, minerals and organic compounds. Sometimes, a pit liner may be needed to ensure the integrity of the earthen pit. The pit liner should act as an impervious barrier between the contained fluids and soil or ground water outside the pit. It is imperative to construct the pit and liner to prevent leakage of pit contents and consequent potential contamination of the surrounding environment. In the United States, the construction of oilfield pits and the need for pit liners is typically governed by state oil and gas regulatory requirements. Standards for the construction and composition of pit liners vary considerably from state to state. Thus, when choosing a pit liner or constructing an oilfield waste pit, it is important to determine the legal requirements applicable in the state where the pit is located.

  7. Optimizing liner implosions for high energy density physics experiments

    SciTech Connect

    Ekdahl, C.; Humphries, S. Jr.

    1996-12-31

    Cylindrical metal shells imploded by magnetic fields - liners - are used as kinetic energy drivers for high energy density physics experiments in hydrodynamics and dynamic material property measurements. There are at least three ways in which liners have been, or are expected to be, used to produce high energy density, i.e., high pressure, in target materials. A common approach uses the liner as a convergent flyer plate, which impacts a material target cylinder after having been shocklessly accelerated across an intervening gap. The resultant shock and piston hydrodynamic flow in the target are used in exploration of a wide variety of phenomena and material properties. Another common method is to slowly compress a liner containing a material sample in a such fashion that little heating occurs. This technique is most useful for investigated physical properties at low temperature and extreme density. Finally, one can use a hybrid approach to shock heat with an impacting liner followed by slower adiabatic, if not isentropic, compression to explore material properties in extrema. The magnetic fields for driving these liners may be produced by either high explosive pulsed power generators or by capacitor banks. Here we will consider only capacitor banks.

  8. Space sail liner

    NASA Astrophysics Data System (ADS)

    Lukyanov, A. V.

    1983-09-01

    Space vehicles, fit to ply between space objects and to transport hundreds of tons, will be necessary for research expeditions to planets and for asteroids materials supply to future space settlements, factories and satellite solar power stations. The means of creating such sail "liners" are discussed in the paper. The liner's solar sail area is dozens to hundreds of km 2. The sail is produced by combining in line small standard controlled units assembled or deployed in space. The equations of motion and sail control are considered. It is shown how superlight rotating reflectors, investigated by the author before, could be used to construct a sail. Another construction may be obtained by means of connecting stiff framework square reflectors and can be easily realized. Using deployable tubes made of composite straps will essentially lighten the square unit framework. Commercially available 4-μm thick aluminized mylar film and considerably thinner film may be used, and its mass will be most of the sail mass. Assembling of such a sail may be carried out on the orbiting assembling station.

  9. Elution behavior of metal ions with mixed glycine-nitric acid eluents in Dowex 50W-X8 column: separation of Th(IV), Ce(IV), Bi(III), Fe(III), and Al(III)

    SciTech Connect

    Eusebius, L.; Ghose, A.; Dey, A.

    1982-01-01

    Distribution coefficients (K) determined by the batch technique in acidic glycine media using Dowex 50W-X8 cation exchanger (H/sup +/-form, 100-200 mesh size) revealed that this medium can effectively be employed to separate a number of tetravalent and trivalent metal ions from bivalent metal ions. In fixed glycine (0.40 M) and varying concentration of nitric acid (0.10 to 1.0 M), a number of mixtures containing two or three metal ions were resolved on columns using about 8 g of exchanger. In 0.40 M glycine-1.0 M HNO/sub 3/ medium, Th(IV)/Ce(IV) were separated from Al(III)/Fe(III)/Bi(III)/Co(II)/Ni(II)/Cu(II)/Zn(II)/Cd(II)/Hg(II)/Pb(II)/Ag(I) and also Al(III)/Bi(III) from a number of divalent metal ions. In 0.40 M glycine-0.50 M HNO/sub 3/ medium, the resolution of following ternary mixtures were also achieved: Th(IV)/Ce(IV)-Al(III)/Bi(III)-Fe(III)/Co(II)/Ni(II)/Cu(II)/Zn(II)/Cd(II)/Hg(II)/Pb(II)/Ag(I). Th(IV)/Al(III)/Fe(III)/Bi(III) were also separated from other divalent metal ions in 1.60 M glycine-0.50 M HNO/sub 3/ medium. The values of K, elution characteristics of metal ions, elution curves, and the results of the resolution of a number of mixtures of metal ions along with standard deviations are reported.

  10. Intercalation of Coordinatively Unsaturated Fe(III) Ion within Interpenetrated Metal-Organic Framework MOF-5.

    PubMed

    Holmberg, Rebecca J; Burns, Thomas; Greer, Samuel M; Kobera, Libor; Stoian, Sebastian A; Korobkov, Ilia; Hill, Stephen; Bryce, David L; Woo, Tom K; Murugesu, Muralee

    2016-06-01

    Coordinatively unsaturated Fe(III) metal sites were successfully incorporated into the iconic MOF-5 framework. This new structure, Fe(III) -iMOF-5, is the first example of an interpenetrated MOF linked through intercalated metal ions. Structural characterization was performed with single-crystal and powder XRD, followed by extensive analysis by spectroscopic methods and solid-state NMR, which reveals the paramagnetic ion through its interaction with the framework. EPR and Mössbauer spectroscopy confirmed that the intercalated ions were indeed Fe(III) , whereas DFT calculations were employed to ascertain the unique pentacoordinate architecture around the Fe(III) ion. Interestingly, this is also the first crystallographic evidence of pentacoordinate Zn(II) within the MOF-5 SBU. This new MOF structure displays the potential for metal-site addition as a framework connector, thus creating further opportunity for the innovative development of new MOF materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Gadolinium(III)-sensitized fluorescence of europium in its mixed-metal compounds with trifluroacetate

    NASA Astrophysics Data System (ADS)

    Kalinovskaya, I. V.; Zadorozhnaya, A. N.

    2017-04-01

    The fluorescence properties of mixed-metal compounds of Eu(III) and Gd(III) with trifluoroacetic acid, Eu1-xGdx(C2F3O2)3·yD·zH2O, where D - 1,10-phenanthroline, 2,2-dipyridil, diphenylguanidine, x = 0, 0.25, 0.5, or 0.7, were studied. Luminescence spectroscopic evidence and the examination of excitation spectra indicate the occurrence of efficient energy transfer from the gadolinium to the europium ion. The greatest promotion of Eu3+ photoluminescence at 615 nm is observed when Eu:Gd = 1:1.

  12. Methods of estimating liner compression.

    PubMed

    Leonardi, S; Penry, J F; Tangorra, F M; Thompson, P D; Reinemann, D J

    2015-10-01

    The aim of this study was to compare 2 methods of measuring overpressure (OP) using a new test device designed to make OP measurements more quickly and accurately. Overpressure was measured with no pulsation (OP np) and with limited pulsation (OP lp) repeatedly on the same cow during a single milking. Each of the 6 liners (3 round liners and 3 triangular liners) used in this study were tested on the same 6 experimental cows. Both OP np and OP lp were measured on all 4 teats of each experimental cow twice for each liner. The order of OP np and OP lp alternated sequentially for each cow test. The OP results for the 6 liners were also compared with liner compression estimated on the same liners with a novel artificial teat sensor (ATS). The OP lp method showed small but significantly higher values than the OP np method (13.9 vs. 13.4 kPa). The OP lp method is recommended as the preferred method as it more closely approximates normal milking condition. Overpressure values decreased significantly between the first and the following measurements, (from 15.0 to 12.4 kPa). We recommend performing the OP test at a consistent time, 1 min after attaching the teatcup to a well-stimulated teat, to reduce the variability produced by OP changing during the peak flow period. The new test device had several advantages over previously published methods of measuring OP. A high correlation between OP and liner compression estimated by the ATS was found, but difficulties were noted when using the ATS with triangular liners. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  13. Megabar liner experiments on Pegasus II

    SciTech Connect

    Lee, H.; Bartsch, R.R.; Bowers, R.L.

    1997-09-01

    Using pulsed power to implode a liner onto a target can produce high shock pressures for many interesting application experiments. With a Pegasus II facility in Los Alamos, a detailed theoretical analysis has indicated that the highest attainable pressure is around 2 Mbar for a best designed aluminum liner. Recently, an interesting composite liner design has been proposed which can boost the shock pressure performance by a factor 4 over the aluminum liner. This liner design was adopted in the first megabar (Megabar-1) liner experiment carried out on Pegasus last year to verify the design concept and to compare the effect of Rayleigh-Taylor instabilities on liner integrity with the code simulations. We present briefly the physical considerations to explain why the composite liner provides the best shock pressure performance. The theoretical modeling and performance of Megabar-1 liner are discussed. Also presented are the first experimental results and the liner design modification for our next experiment.

  14. Metal-seeded growth of III-V semiconductor nanowires: towards gold-free synthesis

    NASA Astrophysics Data System (ADS)

    Dick, Kimberly A.; Caroff, Philippe

    2014-02-01

    Semiconductor nanowires composed of III-V materials have enormous potential to add new functionality to electronics and optical applications. However, integration of these promising structures into applications is severely limited by the current near-universal reliance on gold nanoparticles as seeds for nanowire fabrication. Although highly controlled fabrication is achieved, this metal is entirely incompatible with the Si-based electronics industry. In this Feature we review the progress towards developing gold-free bottom-up synthesis techniques for III-V semiconductor nanowires. Three main categories of nanowire synthesis are discussed: selective-area epitaxy, self-seeding and foreign metal seeding, with main focus on the metal-seeded techniques. For comparison, we also review the development of foreign metal seeded synthesis of silicon and germanium nanowires. Finally, directions for future development and anticipated important trends are discussed. We anticipate significant development in the use of foreign metal seeding in particular. In addition, we speculate that multiple different techniques must be developed in order to replace gold and to provide a variety of nanowire structures and properties suited to a diverse range of applications.

  15. Machine Gun Liner Bond Strength

    DTIC Science & Technology

    2007-08-01

    investigation does not constitute a complete analysis of liner failures in the M2 machine gun. The fact that two different liner-failure modes were...An order-of-magnitude estimate can be made of the bond strength in this case using a standard elastic analysis and some reasonable assumptions... analysis of the forces on the machine gun bullet, it was found that the measured bond strength was adequate to resist the reaction forces produced when

  16. Evaluation of tungsten shaped-charge liners spray-formed using the low-pressure plasma spray process

    SciTech Connect

    Buchanan, E.R.; Sickinger, A.

    1994-12-31

    This paper documents the results of a DARPA Phase 1 SBIR program which was awarded following a solicitation to develop new technologies for the forming of refractory metal shaped-charge liners. Holtgren had proposed to manufacture liners by spraying refractory metal powder onto a rapidly-rotating mandrel inside the chamber of a low-pressure plasma spray system. A total of nine tungsten shaped-charge liners were sprayed during the course of the program. Metallographic evaluation of the liners revealed that the as-sprayed microstructure was dense, averaging 98.5% density. The grain structure is equiaxed and fine, averaging five microns in diameter. The sprayed shapes were then processed to the final liner configuration by cylindrical grinding. The liners were ductile enough to withstand the strains of grinding and normal handling.

  17. Cementing constrained acetabular liners in revision hip replacement: clinical and laboratory observations.

    PubMed

    Mountney, John; Garbuz, Donald S; Greidanus, Nelson V; Masri, Bassam A; Duncan, Clive P

    2004-01-01

    During revision hip arthroplasty, removal of a well-fixed, ingrown metal acetabular component may not be possible. Therefore, a new polyethylene liner can be cemented into the existing shell via the cement locking mechanism. This technique is well recognized, and the cement locking mechanism has proved to be sufficiently strong and durable for clinical use. A constrained polyethylene liner is designed to reduce the risk of hip dislocation by capturing the femoral head. However, there are increased shear forces created at the liner interface as the dislocation is resisted. If a constrained liner is cemented into an ingrown acetabular component, then there is the theoretical risk that these increased shear forces will damage the cement locking mechanism, thus leading to failure of the construct. There are a few clinical series in which a constrained liner has been used with the cement locking mechanism. Overall, the failure rate of the cement locking mechanism is no greater if a constrained liner instead of a standard liner is used. The cement locking mechanism can be strengthened by roughening the backside of a smooth polyethylene liner to improve the cement-polyethylene interface, or by using an all-polyethylene acetabular component that is designed to be used with cement. Whether a smooth metal shell needs to be roughened as well is a matter of debate.

  18. FGD liner experiments with wetlands

    SciTech Connect

    Mitsch, W.J.; Ahn, C.; Wolfe, W.E.

    1999-07-01

    The construction of artificial wetlands for wastewater treatment often requires impermeable liners not only to protect groundwater resources but also to ensure that there is adequate water in the wetland to support appropriate aquatic life, particularly wetland vegetation. Liners or relatively impervious site soils are very important to the success of constructed treatment wetlands in areas where ground water levels are typically close to the ground surface. This study, carried out at the Olentangy River Wetland Research Park, investigated the use of FGD material from sulfur scrubbers as a possible liner material for constructed wetlands. While several studies have investigated the use of FGD material to line ponds, no studies have investigated the use of this material as a liner for constructed wetlands. They used experimental mesocosms to see the effect of FGD liner materials in constructed wetlands on water quality and on wetland plant growth. This paper presents the results of nutrient analyses and physicochemical investigation of leachate and surface outflow water samples collected from the mesocosms. Plant growth and biomass of wetland vegetation are also included in this paper. First two year results are reported by Ahn et al. (1998, 1999). The overall goal of this study is the identification of advantages and disadvantages of using FGD by-product as an artificial liner in constructed wetlands.

  19. Filament wound pressure vessels with load sharing liners for Space Shuttle Orbiter applications

    NASA Technical Reports Server (NTRS)

    Ecord, G. M.

    1976-01-01

    It is recognized that the use of overwrapped pressure vessels with load sharing liners may provide significant weight savings for high pressure gas containment in Space Shuttle Orbiter systems. The technology readiness to produce Kevlar wound vessels with load sharing liners of titanium 6Al-4V, Inconel 718 or cryoformed 301 steel has been demonstrated. It has been estimated that about 400 lbs can be saved in the Orbiter by using overwrapped vessels with load sharing liners instead of monolithic metal designs. Total weight of the composite vessels would be about 1350 lbs as opposed to about 1750 lbs for all-metal vessels.

  20. Abundance anomalies in metal-poor stars from Population III supernova ejecta hydrodynamics

    NASA Astrophysics Data System (ADS)

    Sluder, Alan; Ritter, Jeremy S.; Safranek-Shrader, Chalence; Milosavljević, Miloš; Bromm, Volker

    2016-02-01

    We present a simulation of the long-term evolution of a Population III supernova remnant in a cosmological minihalo. Employing passive Lagrangian tracer particles, we investigate how chemical stratification and anisotropy in the explosion can affect the abundances of the first low-mass, metal-enriched stars. We find that reverse shock heating can leave the inner mass shells at entropies too high to cool, leading to carbon enhancement in the recollapsing gas. This hydrodynamic selection effect could explain the observed incidence of carbon-enhanced metal-poor stars at low metallicity. We further explore how anisotropic ejecta distributions, recently seen in direct numerical simulations of core-collapse explosions, may translate to abundances in metal-poor stars. We find that some of the observed scatter in the Population II abundance ratios can be explained by an incomplete mixing of supernova ejecta, even in the case of only one contributing enrichment event. We demonstrate that the customary hypothesis of fully mixed ejecta clearly fails if post-explosion hydrodynamics prefers the recycling of some nucleosynthetic products over others. Furthermore, to fully exploit the stellar-archaeological programme of constraining the Pop III initial mass function from the observed Pop II abundances, considering these hydrodynamical transport effects is crucial. We discuss applications to the rich chemical structure of ultrafaint dwarf satellite galaxies, to be probed in unprecedented detail with upcoming spectroscopic surveys.

  1. Liner cooling research at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Acosta, Waldo A.

    1987-01-01

    Described are recently completed and current advanced liner research applicable to advanced small gas turbine engines. Research relating to the evolution of fuel efficient small gas turbine engines capable of meeting future commercial and military aviation needs is currently under way at NASA Lewis Research Center. As part of this research, a reverse-flow combustor geometry was maintained while different advanced liner wall cooling techniques were investigated and compared to a baseline combustor. The performance of the combustors featuring counterflow film-cooled (CFFC) panels, transpiration cooled liner walls (TRANS), and compliant metal/ceramic (CMC) walls was obtained over a range of simulated flight conditions of a 16:1 pressure ratio gas turbine engine and fuel/air ratios up to 0.034. All the combustors featured an identical fuel injection system, identical geometric configuration outline, and similar designed internal aerothermodynamics.

  2. Long-term behavior of water content and density in an earthen liner

    USGS Publications Warehouse

    Frank, T.E.; Krapac, I.G.; Stark, T.D.; Strack, G.D.

    2005-01-01

    An extensively instrumented compacted earthen liner was constructed at the Illinois State Geological Survey facility in Champaign, III. in 1987. A pond of water 0.31 m deep was maintained on top of the 7.3 m ?? 14.6 m ?? 0.9 m thick liner for 14 years. One of the goals of the project was to evaluate the long-term performance of a compacted earthen liner by monitoring the long-term changes in water content and density. The water content of the earthen liner showed no trend with depth or time. The liner density remained essentially constant from construction through excavation in 2002. The liner did not become fully saturated. Upon excavation of the liner, the degree of saturation was 80.0??6.3% after 14 years of ponding under a hydraulic head of 0.31 m. The results imply that properly designed and constructed earthen liners may reduce the possibility of pollutants leaching from municipal solid waste containment facilities by remaining partially saturated for years and maintaining the placement density. Journal of Geotechnical and Geoenvironmental Engineering ?? ASCE.

  3. Cyclometalated iridium(III) complexes for phosphorescence sensing of biological metal ions.

    PubMed

    You, Youngmin; Cho, Somin; Nam, Wonwoo

    2014-02-17

    Phosphorescence signaling provides a valuable alternative to conventional bioimaging based on fluorescence. The benefits of using phosphorescent molecules include improved sensitivity and capabilities for effective elimination of background signals by time-gated acquisition. Cyclometalated Ir(III) complexes are promising candidates for facilitating phosphorescent bioimaging because they provide synthetic versatility and excellent phosphorescence properties. In this Forum Article, we present our recent studies on the development of phosphorescence sensors for the detection of metal ions based on cyclometalated iridium(III) complexes. The constructs contained cyclometalating (C^N) ligands with the electron densities and band-gap energies of the C^N ligand structures systematically varied. Receptors that chelated zinc, cupric, and chromium ions were tethered to the ligands to create phosphorescence sensors. The alterations in the C^N ligand structures had a profound influence on the phosphorescence responses to metal ions. Mechanistic studies suggested that the phosphorescence responses could be explained on the basis of the modulation of photoinduced electron transfer (PeT) from the receptor to the photoexcited iridium species. The PeT behaviors strictly adhered to the Rehm-Weller principle, and the occurrence of PeT was located in the Marcus-normal region. It is thus anticipated that improved responses will be obtainable by increasing the excited-state reduction potential of the iridium(III) complexes. Femtosecond transient absorption experiments provided evidence for the presence of an additional photophysical mechanism that involved metal-ion-induced alteration of the intraligand charge-transfer (ILCT) transition state. Utility of the mechanism by PeT and ILCT has been demonstrated for the phosphorescence sensing of biologically important transition-metal ions. In particular, the phosphorescence zinc sensor could report the presence of intracellular zinc pools by

  4. Crystal structure of class III chitinase from pomegranate provides the insight into its metal storage capacity.

    PubMed

    Masuda, Taro; Zhao, Guanghua; Mikami, Bunzo

    2015-01-01

    Chitinase hydrolyzes the β-1,4-glycosidic bond in chitin. In higher plants, this enzyme has been regarded as a pathogenesis-related protein. Recently, we identified a class III chitinase, which functions as a calcium storage protein in pomegranate (Punica granatum) seed (PSC, pomegranate seed chitinase). Here, we solved a crystal structure of PSC at 1.6 Å resolution. Although its overall structure, including the structure of catalytic site and non-proline cis-peptides, was closely similar to those of other class III chitinases, PSC had some unique structural characteristics. First, there were some metal-binding sites with coordinated water molecules on the surface of PSC. Second, many unconserved aspartate residues were present in the PSC sequence which rendered the surface of PSC negatively charged. This acidic electrostatic property is in contrast to that of hevamine, well-characterized plant class III chitinase, which has rather a positively charged surface. Thus, the crystal structure provides a clue for metal association property of PSC.

  5. Review of laser produced multi-keV X-ray sources from metallic foils, cylinders with liner, and low density aerogels

    SciTech Connect

    Girard, Frédéric

    2016-04-15

    Experimental results obtained within the last fifteen years on multi-keV X-ray sources irradiated with nanosecond scale pulse duration 3ω laser light at TW power levels by CEA and collaborators are discussed in this review paper. Experiments were carried out on OMEGA and GEKKO XII laser facilities where emitting materials in the 5–10 keV multi-keV energy range are intermediate Z value metals from titanium to germanium. Results focused on conversion efficiency improvement by a factor of 2 when an underdense plasma is created using a laser pre-pulse on a metallic foil, which is then heated by a second laser pulse delayed in time. Metal coated inner surface walls of plastic cylindrical tube ablated by laser beam impacts showed that plasma confinement doubles X-ray emission duration as it gives adequate plasma conditions (electron temperature and density) over a long period of time. Low-density aerogels (doped with metal atoms uniformly distributed throughout their volume or metal oxides) contained in a plastic cylinder have been developed and their results are comparable to gas targets. A hybrid target concept consisting of a thin metal foil placed at the end of a cylinder filled with low density aerogel has emerged as it could collect benefits from pre-exploded thin foils, efficient laser absorption in aerogel, and confinement by cylinder walls. All target geometry performances are relatively close together at a given photon energy and mainly depend on laser irradiation condition optimizations. Results are compared with gas target performances from recent NIF experiments allowing high electron temperatures over large dimension low density plasmas, which are the principal parameters for efficient multi-keV X-ray production.

  6. Review of laser produced multi-keV X-ray sources from metallic foils, cylinders with liner, and low density aerogels

    NASA Astrophysics Data System (ADS)

    Girard, Frédéric

    2016-04-01

    Experimental results obtained within the last fifteen years on multi-keV X-ray sources irradiated with nanosecond scale pulse duration 3ω laser light at TW power levels by CEA and collaborators are discussed in this review paper. Experiments were carried out on OMEGA and GEKKO XII laser facilities where emitting materials in the 5-10 keV multi-keV energy range are intermediate Z value metals from titanium to germanium. Results focused on conversion efficiency improvement by a factor of 2 when an underdense plasma is created using a laser pre-pulse on a metallic foil, which is then heated by a second laser pulse delayed in time. Metal coated inner surface walls of plastic cylindrical tube ablated by laser beam impacts showed that plasma confinement doubles X-ray emission duration as it gives adequate plasma conditions (electron temperature and density) over a long period of time. Low-density aerogels (doped with metal atoms uniformly distributed throughout their volume or metal oxides) contained in a plastic cylinder have been developed and their results are comparable to gas targets. A hybrid target concept consisting of a thin metal foil placed at the end of a cylinder filled with low density aerogel has emerged as it could collect benefits from pre-exploded thin foils, efficient laser absorption in aerogel, and confinement by cylinder walls. All target geometry performances are relatively close together at a given photon energy and mainly depend on laser irradiation condition optimizations. Results are compared with gas target performances from recent NIF experiments allowing high electron temperatures over large dimension low density plasmas, which are the principal parameters for efficient multi-keV X-ray production.

  7. Extent of fungal growth on fiberglass duct liners with and without biocides under challenging environmental conditions.

    PubMed

    Samimi, Behzad S; Ross, Kristen

    2003-03-01

    Eight brands of fiberglass duct liners, including three that contained biocides, were exposed to challenging environmental conditions that would promote fungal growth. Twenty-four rectangular sheet metal ducts in three groups of eight ducts per group were lined with the eight selected liners. Each group of ducts was exposed to one of the three test conditions within an environmental chamber for a period of 15 days. These conditions were a) 75 percent RH, b) 75 percent RH plus water spray, c) 75 percent RH plus dry nutrient, and d) 75 percent RH plus water plus nutrient. Viable spores of Aspergillus niger were aerosolized into each duct as seed. On the 16th day, air and surface samples for fungal spores were collected from inside ducts. The results of air sampling using N6 sampler and visual inspection indicated that two out of three biocide-containing liners, Permacote and Toughgard, inhibited fungal growth but only under condition A. The third biocide-containing liner, Aeroflex Plus, was effective even when it was wet (conditions A and B). All three biocide-containing liners failed to inhibit fungal growth under conditions C and D. Among the five other types of liners that did not contain biocides, ATCO Flex with a smooth Mylar coating was more preferable, exhibiting lower fungal activity during conditions A, B, and C. All liners failed under condition D when nutrient and water were added together. Surface sampling using adhesive tape failed to produce representative results, apparently due to rough/porous surface of duct liners. It was concluded that duct liners with biocide treatment could be less promoting to microbial growth under high humidity as long as their surfaces remain clean and water-free. A liner with an impermeable and smooth surface seems to be less subject to microbial growth under most conditions than biocide-containing liners having porous and/or rough surfaces.

  8. A review of aqueous-phase VOC transport in modern landfill liners.

    PubMed

    Edil, Tuncer B

    2003-01-01

    Leachates from municipal solid waste (MSW) and hazardous waste landfills contain a wide range of volatile organic compounds (VOCs) in addition to inorganic compounds. VOCs have been shown to migrate and contaminate the surrounding environment and impair the use of groundwater. Therefore, the effectiveness of modern landfill liner systems to minimize migration of VOCs is of concern. Most modern landfills employ a composite liner consisting of a geomembrane overlying a compacted clay liner or a geosynthetic clay liner. The geomembrane is often believed to be the primary barrier to contaminant transport. However, for VOCs, the clay component usually controls the rate of transport since VOCs are shown to diffuse through geomembrane at appreciable rates. Additionally, analyses have shown that transport of volatile organic compounds (VOCs) generally is more critical than transport of inorganic compounds (e.g., toxic heavy metals), even though VOCs are often found at lower concentrations in leachates. Therefore, the effectiveness of modern landfill liner systems to minimize migration of VOCs and transport of VOCs through clay liners and modeling of transport through composite liners merit scrutiny. This paper presents a review of recent research by the author and others on these topics. A systematic and comprehensive approach to determine mass transport parameters for transport of VOCs in liquid phase through compacted clay liners, geosynthetic clay liners (GCLs), and geomembranes has enabled to develop realistic models to predict mass flux of VOCs through modern composite liners and provide a quantitative basis to evaluate potential for transport of dissolved VOCs and the equivalency of different composite liners.

  9. Reduction of Fe(III), Mn(IV), and toxic metals at 100 degrees C by Pyrobaculum islandicum.

    PubMed

    Kashefi, K; Lovley, D R

    2000-03-01

    It has recently been noted that a diversity of hyperthermophilic microorganisms have the ability to reduce Fe(III) with hydrogen as the electron donor, but the reduction of Fe(III) or other metals by these organisms has not been previously examined in detail. When Pyrobaculum islandicum was grown at 100 degrees C in a medium with hydrogen as the electron donor and Fe(III)-citrate as the electron acceptor, the increase in cell numbers of P. islandicum per mole of Fe(III) reduced was found to be ca. 10-fold higher than previously reported. Poorly crystalline Fe(III) oxide could also serve as the electron acceptor for growth on hydrogen. The stoichiometry of hydrogen uptake and Fe(III) oxide reduction was consistent with the oxidation of 1 mol of hydrogen resulting in the reduction of 2 mol of Fe(III). The poorly crystalline Fe(III) oxide was reduced to extracellular magnetite. P. islandicum could not effectively reduce the crystalline Fe(III) oxide minerals goethite and hematite. In addition to using hydrogen as an electron donor for Fe(III) reduction, P. islandicum grew via Fe(III) reduction in media in which peptone and yeast extract served as potential electron donors. The closely related species P. aerophilum grew via Fe(III) reduction in a similar complex medium. Cell suspensions of P. islandicum reduced the following metals with hydrogen as the electron donor: U(VI), Tc(VII), Cr(VI), Co(III), and Mn(IV). The reduction of these metals was dependent upon the presence of cells and hydrogen. The metalloids arsenate and selenate were not reduced. U(VI) was reduced to the insoluble U(IV) mineral uraninite, which was extracellular. Tc(VII) was reduced to insoluble Tc(IV) or Tc(V). Cr(VI) was reduced to the less toxic, less soluble Cr(III). Co(III) was reduced to Co(II). Mn(IV) was reduced to Mn(II) with the formation of manganese carbonate. These results demonstrate that biological reduction may contribute to the speciation of metals in hydrothermal environments and

  10. Reduction of Fe(III), Mn(IV), and Toxic Metals at 100°C by Pyrobaculum islandicum

    PubMed Central

    Kashefi, Kazem; Lovley, Derek R.

    2000-01-01

    It has recently been noted that a diversity of hyperthermophilic microorganisms have the ability to reduce Fe(III) with hydrogen as the electron donor, but the reduction of Fe(III) or other metals by these organisms has not been previously examined in detail. When Pyrobaculum islandicum was grown at 100°C in a medium with hydrogen as the electron donor and Fe(III)-citrate as the electron acceptor, the increase in cell numbers of P. islandicum per mole of Fe(III) reduced was found to be ca. 10-fold higher than previously reported. Poorly crystalline Fe(III) oxide could also serve as the electron acceptor for growth on hydrogen. The stoichiometry of hydrogen uptake and Fe(III) oxide reduction was consistent with the oxidation of 1 mol of hydrogen resulting in the reduction of 2 mol of Fe(III). The poorly crystalline Fe(III) oxide was reduced to extracellular magnetite. P. islandicum could not effectively reduce the crystalline Fe(III) oxide minerals goethite and hematite. In addition to using hydrogen as an electron donor for Fe(III) reduction, P. islandicum grew via Fe(III) reduction in media in which peptone and yeast extract served as potential electron donors. The closely related species P. aerophilum grew via Fe(III) reduction in a similar complex medium. Cell suspensions of P. islandicum reduced the following metals with hydrogen as the electron donor: U(VI), Tc(VII), Cr(VI), Co(III), and Mn(IV). The reduction of these metals was dependent upon the presence of cells and hydrogen. The metalloids arsenate and selenate were not reduced. U(VI) was reduced to the insoluble U(IV) mineral uraninite, which was extracellular. Tc(VII) was reduced to insoluble Tc(IV) or Tc(V). Cr(VI) was reduced to the less toxic, less soluble Cr(III). Co(III) was reduced to Co(II). Mn(IV) was reduced to Mn(II) with the formation of manganese carbonate. These results demonstrate that biological reduction may contribute to the speciation of metals in hydrothermal environments and could

  11. X-ray standing wave investigations of Group III and V metal adsorption on Si(001)

    SciTech Connect

    Qian, Y.; Bedzyk, M.J. |; Lyman, P.F.

    1997-05-01

    Investigations of atomic bonding, surface reconstruction, surface dynamics, and growth kinetics of group III and V metals on Si(001) are important for understanding the initial growth stage of III-V semiconductors on Si(001). Such studies can also provide valuable information for other important issues such as surfactant-mediated epitaxy, surface passivation and delta-doping layers. X-ray standing waves generated by dynamical Bragg diffraction were used as an element-specific structural probe for investigating Ga and Sb adsorption on Si(001). These high-resolution measurements reveal important quantitative structural information regarding the dimerized surface structures, and provide a stringent test for structural models proposed by various theoretical calculations. An overview of the X-ray standing wave technique and its application to surface structure and dynamics is presented.

  12. Biosorption and desorption of lanthanum(III) and neodymium(III) in fixed-bed columns with Sargassum sp.: perspectives for separation of rare earth metals.

    PubMed

    Oliveira, Robson C; Guibal, Eric; Garcia, Oswaldo

    2012-01-01

    Rare earth (RE) metals are essentials for the manufacturing of high-technology products. The separation of RE is complex and expensive; biosorption is an alternative to conventional processes. This work focuses on the biosorption of monocomponent and bicomponent solutions of lanthanum(III) and neodymium(III) in fixed-bed columns using Sargassum sp. biomass. The desorption of metals with HCl 0.10 mol L(-1) from loaded biomass is also carried out with the objective of increasing the efficiency of metal separation. Simple models have been successfully used to model breakthrough curves (i.e., Thomas, Bohart-Adams, and Yoon-Nelson equations) for the biosorption of monocomponent solutions. From biosorption and desorption experiments in both monocomponent and bicomponent solutions, a slight selectivity of the biomass for Nd(III) over La(III) is observed. The experiments did not find an effective separation of the RE studied, but their results indicate a possible partition between the metals, which is the fundamental condition for separation perspectives.

  13. Heavy Metal Tolerance of Fe(III)-Reducing Microbial Communities in Contaminated Creek Bank Soils▿†

    PubMed Central

    Burkhardt, Eva-Maria; Bischoff, Sebastian; Akob, Denise M.; Büchel, Georg; Küsel, Kirsten

    2011-01-01

    Fe(III)-reducing soil enrichment cultures can tolerate 100 μM Cu and Cd, 150 μM Co, 600 μM Ni, and 2,500 μM Zn. Metal-tolerant cultures were dominated by Geobacter-related Deltaproteobacteria and Gram-positive Firmicutes spp. (Clostridia and Sedimentibacter). A Cd- and Cu-tolerant Fe(III)-reducing coculture of Desulfosporosinus and Desulfitobacterium indicated the importance of the Firmicutes for Fe(III) reduction in the presence of metals. PMID:21378042

  14. Characterization of Co(III) EDTA-Reducing Bacteria in Metal- and Radionuclide-Contaminated Groundwater

    SciTech Connect

    Gao, Weimin; Gentry, Terry J; Mehlhorn, Tonia L; Carroll, Sue L; Jardine, Philip M; Zhou, Jizhong

    2010-01-01

    The Waste Area Grouping 5 (WAG5) site at Oak Ridge National Laboratory has a potential to be a field site for evaluating the effectiveness of various bioremediation approaches and strategies. The site has been well studied in terms of its geological and geochemical properties over the past decade. However, despite the importance of microorganisms in bioremediation processes, the microbiological populations at the WAG5 site and their potential in bioremediation have not been similarly evaluated. In this study, we initiated research to characterize the microbial populations in WAG5 groundwater. Approximately 100 isolates from WAG5 groundwater were isolated and selected based on colony morphology. Fifty-five unique isolates were identified by BOX-PCR and subjected to further characterization. 16S rRNA sequences indicated that these isolates belong to seventeen bacterial genera including Alcaligenes (1 isolate), Aquamonas (1), Aquaspirillum (1), Bacillus (10), Brevundimonas (5), Caulobacter (7), Dechloromonas (2), Janibacter (1), Janthinobacterium (2), Lactobacillus (1), Paenibacillus (4), Pseudomonas (9), Rhodoferax (1), Sphingomonas (1), Stenotrophomonas (6), Variovorax (2), and Zoogloea (1). Metal respiration assays identified several isolates, which phylogenically belong or are close to Caulobacter, Stenotrophomonas, Bacillus, Paenibacillus and Pseudomonas, capable of reducing Co(III)EDTA- to Co(II)EDTA{sup 2-} using the defined M1 medium under anaerobic conditions. In addition, using WAG5 groundwater directly as the inoculants, we found that organisms associated with WAG5 groundwater can reduce both Fe(III) and Co(III) under anaerobic conditions. Further assays were then performed to determine the optimal conditions for Co(III) reduction. These assays indicated that addition of various electron donors including ethanol, lactate, methanol, pyruvate, and acetate resulted in metal reduction. These experiments will provide useful background information for future

  15. Military Curricula for Vocational & Technical Education. Metals Processing Specialist, Blocks III and IV, Classroom Course 13-6.

    ERIC Educational Resources Information Center

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

    These curriculum materials are the second section of a four-part, secondary-postsecondary-level course in metals processing. The course is one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. Block III, Introduction to Metallic Arc Welding,…

  16. Evaluation of Comfort Liners for Pilot Helmets.

    DTIC Science & Technology

    1994-09-01

    coated open-cell foam system called a Thermoformed Liner (TFL) by Kaiser Electronics. Coefficient of friction, compression and creep data are generated on each of the II helmet comfort liner materials.

  17. A Versatile Al(III) -Based Metal-Organic Framework with High Physicochemical Stability.

    PubMed

    Wang, Zhuo-Wei; Chen, Min; Liu, Chun-Sen; Wang, Xi; Zhao, Hui; Du, Miao

    2015-11-23

    A unique Al(III) -based metal-organic framework (467-MOF) with two types of square channels has been designed and synthesized by using a flexible tricarboxylate ligand under solvothermal conditions. 467-MOF exhibits superior thermal and chemical stability and, moreover, shows high CO2 sorption selectivity over H2 , with a selectivity, based on the ideal adsorbed solution theory (IAST) of approximately 45 at 273 or 293 K. Furthermore, its solvent-dependent photoluminescence makes it an applicable sensor in the detection of nitrobenzene explosives through fluorescence quenching. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Porous, rigid metal(III)-carboxylate metal-organic frameworks for the delivery of nitric oxide

    NASA Astrophysics Data System (ADS)

    Eubank, Jarrod F.; Wheatley, Paul S.; Lebars, Gaëlle; McKinlay, Alistair C.; Leclerc, Hervé; Horcajada, Patricia; Daturi, Marco; Vimont, Alexandre; Morris, Russell E.; Serre, Christian

    2014-12-01

    The room temperature sorption properties of the biological gas nitric oxide (NO) have been investigated on the highly porous and rigid iron or chromium carboxylate based metal-organic frameworks Material Institut Lavoisier (MIL)-100(Fe or Cr) and MIL-127(Fe). In all cases, a significant amount of NO is chemisorbed at 298 K with a loading capacity that depends both on the nature of the metal cation, the structure and the presence of additional iron(II) Lewis acid sites. In a second step, the release of NO triggered by wet nitrogen gas has been studied by chemiluminescence and indicates that only a partial release of NO occurs as well as a prolonged delivery at the biological level. Finally, an in situ infrared spectroscopy study confirms not only the coordination of NO over the Lewis acid sites and the stronger binding of NO on the additional iron(II) sites, providing further insights over the partial release of NO only in the presence of water at room temperature.

  19. Design and preliminary results of a semitranspiration cooled (Lamilloy) liner for a high-pressure high-temperature combustor

    NASA Technical Reports Server (NTRS)

    Wear, J. D.; Trout, A. M.; Smith, J. M.; Jones, R. E.

    1978-01-01

    A Lamilloy combustor liner was designed, fabricated and tested in a combustor at pressures up to 8 atmospheres. The liner was fabricated of a three layer Lamilloy structure and designed to replace a conventional step louver liner. The liner is to be used in a combustor that provides hot gases to a turbine cooling test facility at pressures up to 40 atmospheres. The Lamilloy liner was tested extensively at lower pressures and demonstrated lower metal temperatures than the conventional liner, while at the same time requiring about 40 percent less cooling air flow. Tests conducted at combustor exit temperatures in excess of 2200 K have not indicated any cooling or durability problems with the Lamilloy linear.

  20. Cost Estimate for Gun Liner Emplacement

    DTIC Science & Technology

    2011-08-01

    NOTES 14. ABSTRACT Recent firing success of an explosively-bonded tantalum alloy gun liner has prompted an examination of other gun liner...usage (1). Soon after this memorandum was written, the Army demonstrated that a medium-caliber barrel with a tantalum -10% tungsten (Ta-10W) liner had...attributed to two main factors: first, a liner was used, rather than a coating; and second, a tantalum alloy with much higher melting point than chromium

  1. Advanced Turbofan Duct Liner Concepts

    NASA Technical Reports Server (NTRS)

    Bielak, Gerald W.; Premo, John W.; Hersh, Alan S.

    1999-01-01

    The Advanced Subsonic Technology Noise Reduction Program goal is to reduce aircraft noise by 10 EPNdB by the year 2000 relative, to 1992 technology. The improvement goal for nacelle attenuation is 25% relative to 1992 technology by 1997 and 50% by 2000. The Advanced Turbofan Duct Liner Concepts Task work by Boeing presented in this document was in support of these goals. The basis for the technical approach was a Boeing study conducted in 1993-94 under NASA/FAA contract NAS1-19349, Task 6, investigating broadband acoustic liner concepts. As a result of this work, it was recommended that linear double layer, linear and perforate triple layer, parallel element, and bulk absorber liners be further investigated to improve nacelle attenuations. NASA LaRC also suggested that "adaptive" liner concepts that would allow "in-situ" acoustic impedance control also be considered. As a result, bias flow and high-temperature liner concepts were also added to the investigation. The major conclusion from the above studies is that improvements in nacelle liner average acoustic impedance characteristics alone will not result in 25% increased nacelle noise reduction relative to 1992 technology. Nacelle design advancements currently being developed by Boeing are expected to add 20-40% more acoustic lining to hardwall regions in current inlets, which is predicted to result in and additional 40-80% attenuation improvement. Similar advancements are expected to allow 10-30% more acoustic lining in current fan ducts with 10-30% more attenuation expected. In addition, Boeing is currently developing a scarf inlet concept which is expected to give an additional 40-80% attenuation improvement for equivalent lining areas.

  2. High Temperature Acoustic Liner Technology

    NASA Technical Reports Server (NTRS)

    Parrott, Tony L.; Jones, Michael G.; Posey, Joe W.

    1999-01-01

    This paper describes work currently in progress at Langley on liner concepts that employ structures that may be suitable for broadband exhaust noise attenuation in high speed flow environments and at elevated temperatures characteristic of HSCT applications. Because such liners will need to provide about 10 dB suppression over a 2 to 3 octave frequency range, conventional single-degree-of-freedom resonant structures will not suffice. Bulk absorbers have the needed broadband absorption characteristic; however, at lower frequencies they tend to be inefficient.

  3. Beryllium liner implosion experiments on the Z accelerator in preparation for Magnetized Liner Inertial Fusion (MagLIF)*

    NASA Astrophysics Data System (ADS)

    McBride, Ryan D.

    2012-10-01

    Magnetized Liner Inertial Fusion (MagLIF) [1] is a concept that involves using a pulsed electrical current to implode an initially-solid, cylindrical metal tube (liner) filled with preheated and magnetized fusion fuel. One- and two-dimensional simulations predict that if sufficient liner integrity can be maintained throughout the implosion, then significant fusion yield (>100 kJ) is possible on the 25-MA, 100-ns Z accelerator. The greatest threat to the liner integrity is the Magneto-Rayleigh-Taylor (MRT) instability, which first develops on the outer liner surface, and then works its way inward toward the inner surface throughout the implosion. Two-dimensional simulations predict that a thick liner, with Router/δR=6, should be robust enough to keep the MRT instability from overly disrupting the fusion burn at stagnation. This talk will present the first experiments designed to study a thick, MagLIF-relevant liner implosion through to stagnation on Z [2]. The use of beryllium for the liner material enabled us to obtain penetrating monochromatic (6151±0.5 eV) radiographs that reveal information about the entire volume of the imploding liner. This talk will also discuss experiments that investigated Z's pulse-shaping capabilities to either shock- or shocklessly-compress the imploding liners [3], as well as our most recent experiments that used 2-micron-thick aluminum sleeves to provide high-contrast tracers for the positions and states of the inner surfaces of the imploding beryllium liners. The radiography data to be presented provide stringent constraints on the simulation tools used by the broader high energy density physics and inertial confinement fusion communities, where quantitative areal density measurements, particularly of convergent fusion targets, are relatively scarce. We will also present power-flow tests of the MagLIF load hardware as well as new micro-B-dot measurements of the azimuthal drive magnetic field that penetrates the initially vacuum

  4. Synthesis, spectroscopic, thermal and anticancer studies of metal-antibiotic chelations: Ca(II), Fe(III), Pd(II) and Au(III) chloramphenicol complexes

    NASA Astrophysics Data System (ADS)

    Al-Khodir, Fatima A. I.; Refat, Moamen S.

    2016-09-01

    Four Ca(II), Fe(III), Pd(II) and Au(III) complexes of chloramphenicol drug have been synthesized and well characterized using elemental analyses, (infrared, electronic, and 1H-NMR) spectra, magnetic susceptibility measurement, and thermal analyses. Infrared spectral data show that the chloramphenicol drug coordinated to Ca(II), Pd(II) and Au(III) metal ions through two hydroxyl groups with 1:1 or 1:2 M ratios, but Fe(III) ions chelated towards chloramphenicol drug via the oxygen and nitrogen atoms of amide group with 1:2 ratio based on presence of keto↔enol form. The X-ray powder diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) techniques were used to identify the nano-size particles of both iron(III) and gold(III) chloramphenicol complexes. The antimicrobial assessments of the chloramphenicol complexes were scanned and collected the results against of some kind of bacteria and fungi. The cytotoxic activity of the gold(III) complex was tested against the human colon carcinoma (HCT-116) and human hepatocellular carcinoma (HepG-2) tumor cell lines.

  5. Early time studies of cylindrical liner implosions at 1 MA on COBRA

    NASA Astrophysics Data System (ADS)

    Atoyan, L.; Byvank, T.; Cahill, A. D.; Hoyt, C. L.; de Grouchy, P. W. L.; Potter, W. M.; Kusse, B. R.; Hammer, D. A.

    2014-12-01

    Tests of the magnetized liner inertial fusion (MagLIF) concept will make use of the 27 MA Z machine at Sandia National Laboratories, Albuquerque, to implode a cylindrical metal liner to compress and heat preheated, magnetized plasma contained within it. While most pulsed power machines produce much lower currents than the Z-machine, there are issues that can still be addressed on smaller scale facilities. Recent work on the Cornell Beam Research Accelerator (COBRA) has made use of 10 mm long and 4 mm diameter metal liners having different wall thicknesses to study the initiation of plasma on the liner's surface as well as axial magnetic field compression [P.-A. Gourdain et al., Nucl. Fusion 53, 083006 (2013)]. This report presents experimental results with non-imploding liners, investigating the impact the liner's surface structure has on initiation and ablation. Extreme ultraviolet (XUV) imaging and optical 12 frame camera imaging were used to observe and assess emission non-uniformities as they developed. Axial and side-on interferometry was used to determine the distribution of plasma near the liner surface, including the impact of non-uniformities during the plasma initiation and ablation phases of the experiments.

  6. Thermodynamic considerations of the vapor phase reactions in III-nitride metal organic vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Sekiguchi, Kazuki; Shirakawa, Hiroki; Chokawa, Kenta; Araidai, Masaaki; Kangawa, Yoshihiro; Kakimoto, Koichi; Shiraishi, Kenji

    2017-04-01

    We analyzed the metal organic vapor phase epitaxial growth mechanism of the III-nitride semiconductors GaN, AlN, and InN by first-principles calculations and thermodynamic analyses. In these analyses, we investigated the decomposition processes of the group III source gases X(CH3)3 (X = Ga, Al, In) at finite temperatures and determined whether the (CH3)2GaNH2 adduct can be formed or not. The results of our calculations show that the (CH3)2GaNH2 adduct cannot be formed in the gas phase in GaN metal organic vapor phase epitaxy (MOVPE), whereas, in AlN MOVPE, the formation of the (CH3)2AlNH2 adduct in the gas phase is exclusive. In the case of GaN MOVPE, trimethylgallium (TMG, [Ga(CH3)3]) decomposition into Ga gas on the growth surface with the assistance of H2 carrier gas, instead of the formation of the (CH3)2GaNH2 adduct, occurs almost exclusively. Moreover, in the case of InN MOVPE, the formation of the (CH3)2InNH2 adduct does not occur and it is relatively easy to produce In gas even without H2 in the carrier gas.

  7. Measured rates of fluoride/metal association correlate with rates of superoxide/metal reactions for Fe(III)EDTA(H2O)- and related complexes.

    PubMed

    Summers, Jack S; Baker, Joseph B; Meyerstein, Dan; Mizrahi, Amir; Zilbermann, Israel; Cohen, Haim; Wilson, Christopher M; Jones, Jamie R

    2008-02-06

    The effects of 10 paramagnetic metal complexes (Fe(III)EDTA(H2O)-, Fe(III)EDTA(OH)2-, Fe(III)PDTA-, Fe(III)DTPA2-, Fe(III)2O(TTHA)2-, Fe(III)(CN)6(3-), Mn(II)EDTA(H2O)2-, Mn(II)PDTA2-, Mn(II)beta-EDDADP2-, and Mn(II)PO4(-)) on F- ion 19F NMR transverse relaxation rates (R2 = 1/T2) were studied in aqueous solutions as a function of temperature. Consistent with efficient relaxation requiring formation of a metal/F- bond, only the substitution inert complexes Fe(III)(CN)6(3-) and Fe(III)EDTA(OH)2- had no measured effect on T2 relaxation of the F- 19F resonance. For the remaining eight complexes, kinetic parameters (apparent second-order rate constants and activation enthalpies) for metal/F- association were determined from the dependence of the observed relaxation enhancements on complex concentration and temperature. Apparent metal/F- association rate constants for these complexes (k(app,F-)) spanned 5 orders of magnitude. In addition, we measured the rates at which O2*- reacts with Fe(III)PDTA-, Mn(II)EDTA(H2O)2-, Mn(II)PDTA2-, and Mn(II)beta-EDDADP2- by pulse radiolysis. Although no intermediate is observed during the reduction of Fe(III)PDTA- by O2*-, each of the Mn(II) complexes reacts with formation of a transient intermediate presumed to form via ligand exchange. These reactivity patterns are consistent with literature precedents for similar complexes. With these data, both k(app,O2-) and k(app,F-) are available for each of the eight reactive complexes. A plot of log(k(app,O2-)) versus log(k(app,F-)) for these eight showed a linear correlation with a slope approximately 1. This correlation suggests that rapid metal/O2*- reactions of these complexes occur via an inner-sphere mechanism whereas formation of an intermediate coordination complex limits the overall rate. This hypothesis is also supported by the very low rates at which the substitution inert complexes (Fe(III)(CN)6(3-) and Fe(III)EDTA(OH)2-) are reduced by O2*-. These results suggest that F- 19F NMR

  8. Biotic generation of arsenic(III) in metal(loid)-contaminated freshwater lake sediments

    SciTech Connect

    Harrington, J.M.; Fendorf, S.E.; Rosenzweig, R.F.

    1998-08-15

    Sediments of Coeur d`Alene Lake, ID, are heavily contaminated with mine tailings that contain high levels of arsenic, iron, lead, and other trace elements. Maximal abundance of redox-active elements such as As and Fe is generally found close to the sediment-water interface, whereas peak abundance of less redox-active elements such as Pb is found at > 25 cm. The suggestion that As is mobile within reduced sediments led the authors to characterize the sediment microbiota with regard to organisms whose activities favor As mobilization. Most probable number (MPN) estimates reveal that the densities of cultivable sulfate-, iron-, and arsenate-reducing bacteria approach 10{sup 6}, 10{sup 5}, and 10{sup 4} cells g{sup {minus}1} wet weight sediment, respectively. Because As is considered more mobile in environments that produce As(III), the authors measured aqueous As(III) generation within As(V)-amended sediment microcosms. In organic acid-stimulated microcosms, > 50% of a 10mM As(V) amendment is transformed to As(III), compared to 30% and 5% in unstimulated microcosms and abiotic controls, respectively. In microcosms amended with an inhibitor of SRB metabolism (molybdate), As(V) reduction was in some cases diminished, suggesting that SRB may contribute to As(V) reduction. The capacity for biotic As(V) reduction clearly exists in CDAL sediments, and the profile of As abundance may be partly attributed to metal(loid)-transforming bacteria.

  9. Segmented ceramic liner for induction furnaces

    DOEpatents

    Gorin, A.H.; Holcombe, C.E.

    1994-07-26

    A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace. 5 figs.

  10. Segmented ceramic liner for induction furnaces

    DOEpatents

    Gorin, Andrew H.; Holcombe, Cressie E.

    1994-01-01

    A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace.

  11. Characterization of EPICOR II Prefilter Liner 16

    SciTech Connect

    Yesso, J D; Pasupathi, V; Lowry, L

    1982-08-01

    As part of the overall TMI-2 Information and Examination Program, EPICOR II Prefilter Liner 16 was examined to provide information to aid in the development of technology for safely processing highly loaded ion-exchange media. The characterization program included sampling and analyses of the liner contents, including ion-exchange media, liquids and gases, as well as examinations of the liner interior and exterior. This report details the handling of the liner, sampling and analysis of the contents, and the examinations of the liner.

  12. A waterproof cast liner earns high marks.

    PubMed

    Selesnick, H; Griffiths, G

    1997-09-01

    Nondisplaced and stable fractures or severe sprains may be casted using fiberglass and a waterproof liner. Application of the liner is illustrated and described here. Allergic reactions, liner bulkiness, cast application and removal, and cost of materials have not proven to be problems. Among 337 patients fitted with this liner, odor, itching, and difficulties with drying were minimal, even though patients swam, bathed, or received hydrotherapy. Minor skin complications occurred in 5.9% of patients. Physician and patient satisfaction with the liner was high.

  13. Ceramic composite liner material for gas turbine combustors

    NASA Technical Reports Server (NTRS)

    Ercegovic, D. B.; Walker, C. L.; Norgren, C. T.

    1984-01-01

    Advanced commercial and military gas turbine engines may operate at combustor outlet temperatures in excess of 1920 K (3000 F). At these temperatures combustors liners experience extreme convective and radiative heat fluxes. The ability of a plasma sprayed ceramic coating to reduce liner metal temperature has been recognized. However, the brittleness of the ceramic layer and the difference in thermal expansion with the metal substrate has caused cracking, spalling and some separation of the ceramic coating. Research directed at turbine tip seals (or shrouds) has shown the advantage of applying the ceramic to a compliant metal pad. This paper discusses recent studies of applying ceramics to combustor liners in which yttria stabilized zirconia plasma sprayed on compliant metal substrates which were exposed to near stoichiometric combustion, presents performance and durability results, and describes a conceptual design for an advanced, small gas turbine combustor. Test specimens were convectively cooled or convective-transpiration cooled and were evaluated in a 10 cm square flame tube combustor at inlet air temperatures of 533 K (500 F) and at a pressure of 0.5 MPa (75 psia). The ceramics were exposed to flame temperatures in excess of 2000 K (3320 F). Results appear very promising with all 30 specimens surviving a screening test and one of two specimens surviving a cyclic durability test.

  14. Novel Materials for Prosthetic Liners

    NASA Technical Reports Server (NTRS)

    Ragolta, Carolina I.; Morford, Megan

    2011-01-01

    Existing materials for prosthetic liners tend to be thick and airtight, causing perspiration to accumulate inside the liner and potentially causing infection and injury that reduce quality of life. The purpose of this project was to examine the suitability of aerogel for prosthetic liner applications. Three tests were performed on several types of aerogel to assess the properties of each material. Moisture vapor permeability was tested by incubating four aerogel varieties with an artificial sweat solution at 37.0 C and less than 20% relative humidity for 24 hours. Two aerogel varieties were eliminated from the study due to difficulties in handling the material, and further testing proceeded with Pyrogel in 2.0 and 6.0 mm thicknesses. Force distribution was tested by compressing samples under a load of 4448 N at a rate of 2.5 mm/min. Biofilm formation was tested in a high-shear CDC Biofilm Reactor. Results showed that 2.0 mm Pyrogel blanket allowed 55.7 plus or minus 28.7% of an artificial sweat solution to transpire, and 35.5 plus or minus 27.8% transpired through 6.0 mm Pyrogel blanket. Samples also outperformed the load-bearing capabilities of existing liner materials. No statistically significant difference was found between the two Pyrogel thicknesses for either moisture vapor permeability or force distribution. In addition, biofilm formation results showed no change between the two Pyrogel thicknesses. The breathability and load bearing properties of aerogel make it a suitable material for application to prosthetic liners.

  15. Canted seating of the Stryker Modular Dual Mobility liner within a Trident hemispherical acetabular shell.

    PubMed

    Eskildsen, Scott M; Olsson, Erik C; Del Gaizo, Daniel J

    2016-03-01

    A 75-year-old woman who suffered a left femoral neck fracture underwent a left total hip arthroplasty using a Stryker Trident (Kalamazoo, MI) hemispherical acetabular shell and Modular Dual Mobility (MDM) metal liner. Post-operative radiographs demonstrated canted seating of the liner. The patient was taken immediately back to the operating room where the acetabular liner appeared well seated superiorly but was in a canted position inferiorly. Removal and replacement was performed and post-operative radiographs demonstrated complete seating. Subsequent follow up at 6 months demonstrated good clinical function with no adverse radiographic findings. Canted seating is a potential complication of the MDM metal liner. Providers should be aware of potential incomplete seating inferiorly despite the superior portion of the liner being well seated.

  16. Novel Iron(III)-Based Metal-Organic Gels with Superior Catalytic Performance toward Luminol Chemiluminescence.

    PubMed

    He, Li; Peng, Zhe Wei; Jiang, Zhong Wei; Tang, Xue Qian; Huang, Cheng Zhi; Li, Yuan Fang

    2017-09-20

    Novel metal-organic gels (MOGs) consisting of iron (Fe(3+)) as the central ion and 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) as the ligand were synthesized by a mild facile strategy. The Fe(III)-containing metal-organic xerogels (Fe-MOXs), obtained after removing the solvents in MOGs, were found to exhibit outstanding performance in the catalysis of luminol chemiluminescence (CL) for the first time even in the absence of extra oxidants such as hydrogen peroxide. The possible CL mechanism was discussed according to the electro/optical measurements, including electron paramagnetic resonance (EPR), UV-vis absorption, and CL spectra, as well as the effects of radical scavengers on Fe-MOXs-catalyzed luminol CL system, suggesting that the CL emission of luminol might originate from the intrinsic oxidase-like catalytic activity of Fe-MOXs on the decomposition of dissolved oxygen. Additionally, the potential practical application of the resulting luminol-Fe-MOXs system was evaluated by the quantitative analysis of dopamine. Good linearity over the range from 0.05 to 0.6 μM was obtained with the limit of detection (LOD, 3σ) of 20.4 nM and acceptable recoveries ranging from 98.6 to 105.4% in human urine. These results may open up the promising application of novel metal-organic gels as highly effective catalysts in the field of chemiluminescence.

  17. Liners for ion transport membrane systems

    DOEpatents

    Carolan, Michael Francis; Miller, Christopher Francis

    2010-08-10

    Ion transport membrane system comprising (a) a pressure vessel comprising an interior, an exterior, an inlet, an inlet conduit, an outlet, and an outlet conduit; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein the inlet and the outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; (c) a gas manifold having an interior surface wherein the gas manifold is in flow communication with the interior region of each of the planar ion transport membrane modules and with the exterior of the pressure vessel; and (d) a liner disposed within any of the inlet conduit, the outlet conduit, and the interior surface of the gas manifold.

  18. Metal-Assisted Oxo Atom Addition to an Fe(III) Thiolate.

    PubMed

    Villar-Acevedo, Gloria; Lugo-Mas, Priscilla; Blakely, Maike N; Rees, Julian A; Ganas, Abbie S; Hanada, Erin M; Kaminsky, Werner; Kovacs, Julie A

    2017-01-11

    Cysteinate oxygenation is intimately tied to the function of both cysteine dioxygenases (CDOs) and nitrile hydratases (NHases), and yet the mechanisms by which sulfurs are oxidized by these enzymes are unknown, in part because intermediates have yet to be observed. Herein, we report a five-coordinate bis-thiolate ligated Fe(III) complex, [Fe(III)(S2(Me2)N3(Pr,Pr))](+) (2), that reacts with oxo atom donors (PhIO, IBX-ester, and H2O2) to afford a rare example of a singly oxygenated sulfenate, [Fe(III)(η(2)-S(Me2)O)(S(Me2))N3(Pr,Pr)](+) (5), resembling both a proposed intermediate in the CDO catalytic cycle and the essential NHase Fe-S(O)(Cys114) proposed to be intimately involved in nitrile hydrolysis. Comparison of the reactivity of 2 with that of a more electron-rich, crystallographically characterized derivative, [Fe(III)S2(Me2)N(Me)N2(amide)(Pr,Pr)](-) (8), shows that oxo atom donor reactivity correlates with the metal ion's ability to bind exogenous ligands. Density functional theory calculations suggest that the mechanism of S-oxygenation does not proceed via direct attack at the thiolate sulfurs; the average spin-density on the thiolate sulfurs is approximately the same for 2 and 8, and Mulliken charges on the sulfurs of 8 are roughly twice those of 2, implying that 8 should be more susceptible to sulfur oxidation. Carboxamide-ligated 8 is shown to be unreactive towards oxo atom donors, in contrast to imine-ligated 2. Azide (N3(-)) is shown to inhibit sulfur oxidation with 2, and a green intermediate is observed, which then slowly converts to sulfenate-ligated 5. This suggests that the mechanism of sulfur oxidation involves initial coordination of the oxo atom donor to the metal ion. Whether the green intermediate is an oxo atom donor adduct, Fe-O═I-Ph, or an Fe(V)═O remains to be determined.

  19. THE MOST METAL-POOR STARS. III. THE METALLICITY DISTRIBUTION FUNCTION AND CARBON-ENHANCED METAL-POOR FRACTION , ,

    SciTech Connect

    Yong, David; Norris, John E.; Bessell, M. S.; Asplund, M.; Christlieb, N.; Beers, Timothy C.; Barklem, P. S.; Frebel, Anna; Ryan, S. G. E-mail: jen@mso.anu.edu.au E-mail: martin@mso.anu.edu.au E-mail: beers@pa.msu.edu E-mail: afrebel@mit.edu

    2013-01-01

    We examine the metallicity distribution function (MDF) and fraction of carbon-enhanced metal-poor (CEMP) stars in a sample that includes 86 stars with [Fe/H] {<=} -3.0, based on high-resolution, high signal-to-noise spectroscopy, of which some 32 objects lie below [Fe/H] = -3.5. After accounting for the completeness function, the 'corrected' MDF does not exhibit the sudden drop at [Fe/H] = -3.6 that was found in recent samples of dwarfs and giants from the Hamburg/ESO survey. Rather, the MDF decreases smoothly down to [Fe/H] = -4.1. Similar results are obtained from the 'raw' MDF. We find that the fraction of CEMP objects below [Fe/H] = -3.0 is 23% {+-} 6% and 32% {+-} 8% when adopting the Beers and Christlieb and Aoki et al. CEMP definitions, respectively. The former value is in fair agreement with some previous measurements, which adopt the Beers and Christlieb criterion.

  20. New Powder Technologies for Molybdenum Alloy Gun Barrel Liners

    DTIC Science & Technology

    1985-06-01

    bored from swaged rods (refs 1,2). Such liners failed after only a few rounds; transverse and longitudinal cracks were observed. A helical twisted 0.50...used by Nuclear Metals, Inc., Concord, MA (refs 7,8). For the REP, a water-cooled tungsten -tipped cathode is used to strike an electric arc to the... tungsten -tipped cathode, which has been found to introduce tungsten contamination. Both versions of the process have essentially the same constraint on

  1. The Fusion Gain Analysis of the Inductively Driven Liner Compression Based Fusion

    NASA Astrophysics Data System (ADS)

    Shimazu, Akihisa; Slough, John

    2016-10-01

    An analytical analysis of the fusion gain expected in the inductively driven liner compression (IDLC) based fusion is conducted to identify the fusion gain scaling at various operating conditions. The fusion based on the IDLC is a magneto-inertial fusion concept, where a Field-Reversed Configuration (FRC) plasmoid is compressed via the inductively-driven metal liner to drive the FRC to fusion conditions. In the past, an approximate scaling law for the expected fusion gain for the IDLC based fusion was obtained under the key assumptions of (1) D-T fuel at 5-40 keV, (2) adiabatic scaling laws for the FRC dynamics, (3) FRC energy dominated by the pressure balance with the edge magnetic field at the peak compression, and (4) the liner dwell time being liner final diameter divided by the peak liner velocity. In this study, various assumptions made in the previous derivation is relaxed to study the change in the fusion gain scaling from the previous result of G ml1 / 2 El11 / 8 , where ml is the liner mass and El is the peak liner kinetic energy. The implication from the modified fusion gain scaling on the performance of the IDLC fusion reactor system is also explored.

  2. A Finite Element Theory for Predicting the Attenuation of Extended-Reacting Liners

    NASA Technical Reports Server (NTRS)

    Watson, W. R.; Jones, M. G.

    2009-01-01

    A non-modal finite element theory for predicting the attenuation of an extended-reacting liner containing a porous facesheet and located in a no-flow duct is presented. The mathematical approach is to solve separate wave equations in the liner and duct airway and to couple these two solutions by invoking kinematic constraints at the facesheet that are consistent with a continuum theory of fluid motion. Given the liner intrinsic properties, a weak Galerkin finite element formulation with cubic polynomial basis functions is used as the basis for generating a discrete system of acoustic equations that are solved to obtain the coupled acoustic field. A state-of-the-art, asymmetric, parallel, sparse equation solver is implemented that allows tens of thousands of grid points to be analyzed. A grid refinement study is presented to show that the predicted attenuation converges. Excellent comparison of the numerically predicted attenuation to that of a mode theory (using a Haynes 25 metal foam liner) is used to validate the computational approach. Simulations are also presented for fifteen porous plate, extended-reacting liners. The construction of some of the porous plate liners suggest that they should behave as resonant liners while the construction of others suggest that they should behave as broadband attenuators. In each case the finite element theory is observed to predict the proper attenuation trend.

  3. Energy transfer through a multi-layer liner for shaped charges

    DOEpatents

    Skolnick, Saul; Goodman, Albert

    1985-01-01

    This invention relates to the determination of parameters for selecting materials for use as liners in shaped charges to transfer the greatest amount of energy to the explosive jet. Multi-layer liners constructed of metal in shaped charges for oil well perforators or other applications are selected in accordance with the invention to maximize the penetrating effect of the explosive jet by reference to four parameters: (1) Adjusting the explosive charge to liner mass ratio to achieve a balance between the amount of explosive used in a shaped charge and the areal density of the liner material; (2) Adjusting the ductility of each layer of a multi-layer liner to enhance the formation of a longer energy jet; (3) Buffering the intermediate layers of a multi-layer liner by varying the properties of each layer, e.g., composition, thickness, ductility, acoustic impedance and areal density, to protect the final inside layer of high density material from shattering upon impact of the explosive force and, instead, flow smoothly into a jet; and (4) Adjusting the impedance of the layers in a liner to enhance the transmission and reduce the reflection of explosive energy across the interface between layers.

  4. Enhanced anti-cancer activities of a gold(III) pyrrolidinedithiocarbamato complex incorporated in a biodegradable metal-organic framework.

    PubMed

    Sun, Raymond Wai-Yin; Zhang, Ming; Li, Dan; Li, Mian; Wong, Alice Sze-Tsai

    2016-10-01

    An anti-cancer active gold(III) pyrrolidinedithiocarbamato complex [(PDTC)Au(III)Cl2] (1) has been synthesized and characterized by means of X-ray crystallography. Compared to the pyrrolidinedithiocarbamate ligand itself, this gold(III) complex displays an up to 33-fold higher anti-cancer potency towards a panel of cancer cell lines including the cisplatin-resistant ovarian carcinoma cell line (A2780cis). As demonstrated by a set of Transwell® assay-based cytotoxicity experiments, incorporating this gold(III) complex in a zinc-based biodegradable metal-organic framework (MOF) displays a significant enhancement in anti-cancer activity towards A2780cis than the gold(III) complex alone. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Elastic Plastic Fracture Analysis of an Aluminum COPV Liner

    NASA Technical Reports Server (NTRS)

    Forth, Scott; Gregg, Bradley; Bailey, Nathaniel

    2012-01-01

    Onboard any space-launch vehicle, composite over-wrapped pressure vessels (COPVs) may be utilized by propulsion or environmental control systems. The failure of a COPV has the potential to be catastrophic, resulting in the loss of vehicle, crew or mission. The latest COPV designs have reduced the wall-thickness of the metallic liner to the point where the material strains plastically during operation. At this time, the only method to determine the damage tolerance lifetime (safe-life) of a plastically responding metallic liner is through full-scale COPV testing. Conducting tests costs substantially more and can be far more time consuming than performing an analysis. As a result of this cost, there is a need to establish a qualifying process through the use of a crack growth analysis tool. This paper will discuss fracture analyses of plastically responding metallic liners in COPVs. Uni-axial strain tests have been completed on laboratory specimens to collect elastic-plastic crack growth data. This data has been modeled with the crack growth analysis tool, NASGRO 6.20 to predict the response of laboratory specimens and subsequently the complexity of a COPV.

  6. Gas Generation from K East Basin Sludges and Irradiated Metallic Uranium Fuel Particles Series III Testing

    SciTech Connect

    Schmidt, Andrew J.; Delegard, Calvin H.; Bryan, Samuel A.; Elmore, Monte R.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.

    2003-08-01

    The path forward for managing of Hanford K Basin sludge calls for it to be packaged, shipped, and stored at T Plant until final processing at a future date. An important consideration for the design and cost of retrieval, transportation, and storage systems is the potential for heat and gas generation through oxidation reactions between uranium metal and water. This report, the third in a series (Series III), describes work performed at the Pacific Northwest National Laboratory (PNNL) to assess corrosion and gas generation from irradiated metallic uranium particles (fuel particles) with and without K Basin sludge addition. The testing described in this report consisted of 12 tests. In 10 of the tests, 4.3 to 26.4 g of fuel particles of selected size distribution were placed into 60- or 800-ml reaction vessels with 0 to 100 g settled sludge. In another test, a single 3.72-g fuel fragment (i.e., 7150-mm particle) was placed in a 60 ml reaction vessel with no added sludge. The twelfth test contained only sludge. The fuel particles were prepared by crushing archived coupons (samples) from an irradiated metallic uranium fuel element. After loading the sludge materials (whether fuel particles, mixtures of fuel particles and sludge, or sludge-only) into reaction vessels, the solids were covered with an excess of K Basin water, the vessels closed and connected to a gas measurement manifold, and the vessels back-flushed with inert neon cover gas. The vessels were then heated to a constant temperature. The gas pressures and temperatures were monitored continuously from the times the vessels were purged. Gas samples were collected at various times during the tests, and the samples analyzed by mass spectrometry. Data on the reaction rates of uranium metal fuel particles with water as a function of temperature and particle size were generated. The data were compared with published studies on metallic uranium corrosion kinetics. The effects of an intimate overlying sludge layer

  7. Low-energy Population III supernovae and the origin of extremely metal-poor stars

    NASA Astrophysics Data System (ADS)

    Chen, Ke-Jung; Heger, Alexander; Whalen, Daniel J.; Moriya, Takashi J.; Bromm, Volker; Woosley, S. E.

    2017-06-01

    Some ancient, dim, metal-poor stars may have formed in the ashes of the first supernovae (SNe). If their chemical abundances can be reconciled with the elemental yields of specific Population III (Pop III) explosions, they could reveal the properties of primordial stars. But multidimensional simulations of such explosions are required to predict their yields because dynamical instabilities can dredge material up from deep in the ejecta that would otherwise be predicted to fall back on to the central remnant and be lost in one-dimensional (1D) models. We have performed two-dimensional (2D) numerical simulations of two low-energy Pop III SNe, a 12.4 M⊙ explosion and a 60 M⊙ explosion, and find that they produce elemental yields that are a good fit to those measured in the most iron-poor star discovered to date, SMSS J031300.36-670839.3 (J031300). Fallback on to the compact remnant in these weak explosions accounts for the lack of measurable iron in J031300 and its low iron-group abundances in general. Our 2D explosions produce higher abundances of heavy elements (atomic number Z > 20) than their 1D counterparts due to dredge-up by fluid instabilities. Since almost no 56Ni is ejected by these weak SNe, their low luminosities will prevent their detection in the near-infrared with the James Webb Space Telescope and future 30-m telescopes on the ground. The only evidence that they ever occurred will be in the fossil abundance record.

  8. III-V nanocrystals capped with molecular metal chalcogenide ligands: high electron mobility and ambipolar photoresponse.

    PubMed

    Liu, Wenyong; Lee, Jong-Soo; Talapin, Dmitri V

    2013-01-30

    In this work, we synthesized InP and InAs nanocrystals (NCs) capped with different inorganic ligands, including various molecular metal chalcogenide complexes (MCCs) and chalcogenide ions. We found that MCCs and chalcogenide ions can quantitatively displace organic ligands from the surface of III-V NCs and serve as the inorganic capping groups for III-V NC surfaces. These inorganic ligands stabilize colloidal solutions of InP and InAs NCs in polar solvents and greatly facilitate charge transport between individual NCs. Charge transport studies revealed high electron mobility in the films of MCC-capped InP and InAs NCs. For example, we found that bridging InAs NCs with Cu(7)S(4)(-) MCC ligands can lead to very high electron mobility exceeding 15 cm(2)/(V s). In addition, we observed unprecedented ambipolar (positive/negative) photoresponse of MCC-capped InAs NC solids that changed sign depending on the ligand chemistry, illumination wavelength, and doping of the NC solid. For example, the sign of photoconductance of InAs NCs capped with Cu(7)S(4)(-) or Sn(2)S(6)(4-) ions converted from positive at 0.80 and 0.95 eV to negative at 1.27 and 1.91 eV. We propose an explanation of this unusually complex photoconductivity of InAs NC solids.

  9. Segmented Liner to Control Mode Scattering

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Jones, Michael G.; Brown, Martha C.

    2013-01-01

    The acoustic performance of duct liners can be improved by segmenting the treatment. In a segmented liner treatment, one stage of liner reduces the target sound and scatters energy into other acoustic modes, which are attenuated by a subsequent stage. The Curved Duct Test Rig is an experimental facility in which sound incident on the liner can be generated in a specific mode and the scatter of energy into other modes can be quantified. A series of experiments is performed in which the baseline configuration is asymmetric, that is, a liner is on one side wall of the test duct and the wall opposite is acoustically hard. Segmented liner treatment is achieved by progressively replacing sections of the hard wall opposite with liner in the axial direction, from 25% of the wall surface to 100%. It is found that the energy scatter from the (0,0) to the (0,1) mode reduces as the percentage of opposite wall treatment increases, and the frequency of peak attenuation shifts toward higher frequency. Similar results are found when the incident mode is of order (0,1) and scatter is into the (0,0) mode. The propagation code CDUCT-LaRC is used to predict the effect of liner segmenting on liner performance. The computational results show energy scatter and the effect of liner segmentation that agrees with the experimental results. The experiments and computations both show that segmenting the liner treatment is effective to control the scatter of incident mode energy into other modes. CDUCT-LaRC is shown to be a valuable tool to predict trends of liner performance with liner configuration.

  10. Magnetized Target Fusion Driven by Plasma Liners

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Eskridge, Richard; Smith, James; Lee, Michael; Richeson, Jeff; Schmidt, George; Knapp, Charles E.; Kirkpatrick, Ronald C.; Turchi, Peter J.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    Magnetized target fusion (MTF) attempts to combine the favorable attributes of magnetic confinement fusion (MCF) for energy confinement with the attributes of inertial confinement fusion (ICF) for efficient compression heating and wall-free containment of the fusing plasma. It uses a material liner to compress and contain a magnetized plasma. For practical applications, standoff drivers to deliver the imploding momentum flux to the target plasma remotely are required. Spherically converging plasma jets have been proposed as standoff drivers for this purpose. The concept involves the dynamic formation of a spherical plasma liner by the merging of plasma jets, and the use of the liner so formed to compress a spheromak or a field reversed configuration (FRC). For the successful implementation of the scheme, plasma jets of the requisite momentum flux density need to be produced. Their transport over sufficiently large distances (a few meters) needs to be assured. When they collide and merge into a liner, relative differences in velocity, density and temperature of the jets could give rise to instabilities in the development of the liner. Variation in the jet properties must be controlled to ensure that the growth rate of the instabilities are not significant over the time scale of the liner formation before engaging with the target plasma. On impact with the target plasma, some plasma interpenetration might occur between the liner and the target. The operating parameter space needs to be identified to ensure that a reasonably robust and conducting contact surface is formed between the liner and the target. A mismatch in the "impedance" between the liner and the target plasma could give rise to undesirable shock heating of the liner leading to increased entropy (thermal losses) in the liner. Any irregularities in the liner will accentuate the Rayleigh-Taylor instabilities during the compression of the target plasma by the liner.

  11. Metal interferences and their removal prior to the determination of As(T) and As(III) in acid mine waters by hydride generation atomic absorption spectrometry

    USGS Publications Warehouse

    McCleskey, R. Blaine; Nordstrom, D. Kirk; Ball, James W.

    2003-01-01

    Hydride generation atomic absorption spectrometry (HGAAS) is a sensitive and selective method for the determination of total arsenic (arsenic(III) plus arsenic(V)) and arsenic(III); however, it is subject to metal interferences for acid mine waters. Sodium borohydride is used to produce arsine gas, but high metal concentrations can suppress arsine production. This report investigates interferences of sixteen metal species including aluminum, antimony(III), antimony(V), cadmium, chromium(III), chromium(IV), cobalt, copper(II), iron(III), iron(II), lead, manganese, nickel, selenium(IV), selenium(VI), and zinc ranging in concentration from 0 to 1,000 milligrams per liter and offers a method for removing interfering metal cations with cation exchange resin. The degree of interference for each metal without cation-exchange on the determination of total arsenic and arsenic(III) was evaluated by spiking synthetic samples containing arsenic(III) and arsenic(V) with the potential interfering metal. Total arsenic recoveries ranged from 92 to 102 percent for all metals tested except antimony(III) and antimony(V) which suppressed arsine formation when the antimony(III)/total arsenic molar ratio exceeded 4 or the antimony(V)/total arsenic molar ratio exceeded 2. Arsenic(III) recoveries for samples spiked with aluminum, chromium(III), cobalt, iron(II), lead, manganese, nickel, selenium(VI), and zinc ranged from 84 to 107 percent over the entire concentration range tested. Low arsenic(III) recoveries occurred when the molar ratios of metals to arsenic(III) were copper greater than 120, iron(III) greater than 70, chromium(VI) greater than 2, cadmium greater than 800, antimony(III) greater than 3, antimony(V) greater than 12, or selenium(IV) greater than 1. Low recoveries result when interfering metals compete for available sodium borohydride, causing incomplete arsine production, or when the interfering metal oxidizes arsenic(III). Separation of interfering metal cations using

  12. Trace elements and heavy metals in hair of stage III breast cancer patients.

    PubMed

    Benderli Cihan, Yasemin; Sözen, Selim; Oztürk Yıldırım, Sema

    2011-12-01

    This prospective study was designed to compare the hair levels of 36 elements in 52 patients with stage III breast cancer to those of an equal number of healthy individuals. Principal component and cluster analysis were used for source of identification and apportionment of heavy metals and trace elements in these two groups. A higher average level of iron was found in samples from patients while controls had higher levels of calcium. Both patients and controls had elevated levels of tin, magnesium, zinc, and sodium. Almost all element values in cancer patients showed higher dispersion and asymmetry than in healthy controls. Between the two groups, there were statistically significant differences in the concentrations of silver, arsenic, gold, boron, barium, beryllium, calcium, cadmium, cerium, cobalt, cesium, gadolinium, manganese, nickel, lead, antimony, scandium, selenium, and zinc (p < 0.05). Strong positive correlations were found between lead and gold (r = 0.785) in the cancer group and between palladium and cobalt (r = 0.945) in the healthy individuals. Our results show that there are distinct patterns of heavy metals and trace elements in the hair of breast cancer patients in comparison to healthy controls. These results could be of significance in the diagnosis of breast cancer.

  13. IRIDIUM LINER FOR NASA 5 LBF CLASS MATERIAL TEST CHAMBER IRIDIUM LINER FOR ATLANTIC RESEARCH CORPORA

    NASA Technical Reports Server (NTRS)

    1995-01-01

    IRIDIUM LINER FOR NASA 5 LBF CLASS MATERIAL TEST CHAMBER IRIDIUM LINER FOR ATLANTIC RESEARCH CORPORATION 5 LBF CLASS ROCKET CHAMBER 25 LBF CLASS 75 HFC 25 TAC CERAMIC COMPOSITE ROCKET CHAMBER FROM REFRACTURY COMPOSITES INC. PURCHASE ORDER C-551941-

  14. Wear materials; 2: Optimizing liner alloy choice

    SciTech Connect

    Stefanovic, T. )

    1993-12-01

    This paper describes a new liner designed for a copper ore crusher in Yugoslavia. The experience gained over the past ten years of operation at the Bor copper mines has shown that correct selection of wear material for crusher liners is critical to successful plant performance. With the new wear resistant liners, the crusher development program has increased the concentrator throughput from 8.0 to 9.6 million tons/year. The ultimate goal of the project is to identify the proper liner material that will extend liner life, reduce cyclic stress on major crusher components, and simplify crusher control and adjustment. This paper describes the various liners materials and the mechanisms of wear.

  15. Magnetized Target Fusion Driven by Plasma Liners

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Cassibry, Jason; Eskridge, Richard; Kirkpatrick, Ronald C.; Knapp, Charles E.; Lee, Michael; Martin, Adam; Smith, James; Wu, S. T.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    For practical applications of magnetized target fusion, standoff drivers to deliver the imploding momentum flux to the target plasma remotely are required. Quasi-spherically converging plasma jets have been proposed as standoff drivers for this purpose. The concept involves the dynamic formation of a quasi-spherical plasma liner by the merging of plasma jets, and the use of the liner so formed to compress a spheromak or a field reversed configuration (FRC). Theoretical analysis and computer modeling of the concept are presented. It is shown that, with the appropriate choice of the flow parameters in the liner and the target, the impact between the liner and the target plasma can be made to be shockless in the liner or to generate at most a very weak shock in the liner. Additional information is contained in the original extended abstract.

  16. Calcium hydroxide liners: a literature review

    PubMed Central

    Arandi, Naji Ziad

    2017-01-01

    Objective This review integrates the literature on cavity liners and current concepts of pulp protection with the aim of establishing a better understanding of the role of calcium hydroxide as a cavity liner. Materials and methods A search was conducted through PubMed, MEDLINE, and Ovid for articles with the criteria for the following terms: cavity liners and bases, pulp protection, and calcium hydroxide liners. No specific inclusion or exclusion criteria were applied as to what articles would be included in this review. It was hoped that the extent of the literature reviewed would be as comprehensive as possible. Conclusion This review underlines the fact that calcium hydroxide liners should only be used in the deepest spots in the cavity where the remaining dentine thickness is ≤0.5 mm. A protective layer of resin-modified glass ionomer should always follow the application of calcium hydroxide liners. PMID:28761378

  17. Magnetized Target Fusion Driven by Plasma Liners

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Cassibry, Jason; Eskridge, Richard; Kirkpatrick, Ronald C.; Knapp, Charles E.; Lee, Michael; Martin, Adam; Smith, James; Wu, S. T.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    For practical applications of magnetized target fusion, standoff drivers to deliver the imploding momentum flux to the target plasma remotely are required. Quasi-spherically converging plasma jets have been proposed as standoff drivers for this purpose. The concept involves the dynamic formation of a quasi-spherical plasma liner by the merging of plasma jets, and the use of the liner so formed to compress a spheromak or a field reversed configuration (FRC). Theoretical analysis and computer modeling of the concept are presented. It is shown that, with the appropriate choice of the flow parameters in the liner and the target, the impact between the liner and the target plasma can be made to be shockless in the liner or to generate at most a very weak shock in the liner. Additional information is contained in the original extended abstract.

  18. The Circum-Galactic Environment of LINERs

    NASA Astrophysics Data System (ADS)

    Krongold, Y.; Dultzin-Hacyan, D.; Marziani, P.; de Diego, J. A.

    In this paper, we study the circumgalactic environment of LINER host galaxies, in a sample of 166 objects drawn from a Multifrequency Catalogue of LINERs by Carrillo et.1999). The aim of our work is to compare the environment of different types of LINERs, therefore we subdivided our sample in three groups: LINERs type, type, and transition objects (TL). The search has been carried out on the Digitized Sky Survey (DSS) up to a projected linear distance of 300using methods applied in several previous studies. We found that type LINERs and TLs seem to possess a richer environment than those of type. In addition, type LINERs and TLs show large companions with frequency similar to that of bright IRAS galaxies and Seyfert 2 host galaxies. We suggest that an evolutionary sequence from starbursting systems, to type and eventually to type-1 AGN, may be appropriate for most AGN and may be independent of luminosity.

  19. Helical plasma striations in liners in the presence of an external axial magnetic field

    NASA Astrophysics Data System (ADS)

    Atoyan, L.; Hammer, D. A.; Kusse, B. R.; Byvank, T.; Cahill, A. D.; Greenly, J. B.; Pikuz, S. A.; Shelkovenko, T. A.

    2016-02-01

    Awe et al. found on the 20 MA Z machine [Acta Phys. Pol. A 115, 956 (2009)] that applying an externally generated axial magnetic field to an imploding liner leads to a helical pattern in the liner when viewed with soft x-ray radiography ([Phys. Rev. Lett. 111, 235005 (2013)] and [Phys. Plasmas 21, 056303 (2014)]). Here, we show that this phenomenon is also observed in extreme ultraviolet self-emission images of 10 mm long cylindrical metal liners having varying diameters and varying wall thicknesses on a 1 MA, 100-200 ns pulsed power generator. The magnetic field in these experiments is created using either twisted return current wires positioned close to the liner, generating a time-varying Bz, or a Helmholtz coil, generating a steady-state Bz.

  20. Long Term Results of Liner Polyethylene Cementation Technique in Revision for Peri-acetabular Osteolysis.

    PubMed

    Rivkin, Gurion; Kandel, Leonid; Qutteineh, Bilal; Liebergall, Meir; Mattan, Yoav

    2015-06-01

    Patients with peri-acetabular osteolysis around a well fixed cementless acetabular component may be treated with liner exchange. When the locking mechanism is unreliable or unavailable, cementing the liner into the fixed acetabular component is a feasible option. The purpose of this study was to evaluate the clinical and radiographic long term results of this technique. Forty hip revisions with liner cementation in 37 patients were performed. The minimum follow up was 10 years. Modified Harris Hip Score and recent x rays were reviewed. Four hips were re-revised. Two patients were diagnosed with exacerbation of osteolysis but refused revision. Dislocation rate was relatively high (16%). Liner cementation technique in revision hip surgery is useful in patients with a well fixed metal backed acetabular component.

  1. Graphical Acoustic Liner Design and Analysis Tool

    NASA Technical Reports Server (NTRS)

    Howerton, Brian M. (Inventor); Jones, Michael G. (Inventor)

    2016-01-01

    An interactive liner design and impedance modeling tool comprises software utilized to design acoustic liners for use in constrained spaces, both regularly and irregularly shaped. A graphical user interface allows the acoustic channel geometry to be drawn in a liner volume while the surface impedance calculations are updated and displayed in real-time. A one-dimensional transmission line model may be used as the basis for the impedance calculations.

  2. Duct Liner Optimization for Turbomachinery Noise Sources

    DTIC Science & Technology

    1975-11-01

    AD-A279 441lIIIflhIh* NASA TECHNICAL NASA TMA X-72789 MEMORANDUM oo £ 00 r-:. DUCT LINER OPTIMIZATION FOR TURBOMACHINERY w NOISE SOURCES By Harold C...Recipient’s r.atalog No. NASA TM X-72789! 4 Title diid Subtitle 5. Rewrt Date Duct Liner Optimization for Turbomachinery Noise Sources November 1975...profiles is combined wit., a numerical minimization algorithm to predict optimal liner configurations having one, two, and three sections. Source models

  3. Chiroptical spectra of a series of tetrakis((+)–3–heptafluorobutylyrylcamphorato)lanthanide(III) with an encapsulated alkali metal ion: circularly polarized luminescence and absolute chiral structures for the Eu(III) and Sm(III) complexes

    PubMed Central

    Lunkley, Jamie L.; Shirotani, Dai; Yamanari, Kazuaki; Kaizaki, Sumio; Muller, Gilles

    2011-01-01

    The luminescence and circularly polarized luminescence (CPL) spectra of MI[Eu((+)–hfbc)4] show a similar behavior to the exciton CD in the intraligand π–π* transitions when the alkali metal ions and solvents are manipulated. There is a difference in susceptibility in solvation toward the alkali metal ions but not toward the Eu(III) ion, as in the case of axially symmetric DOTA–type compounds. The remarkable CPL in the 4f–4f transitions provide much more information on stereospecific formation of chiral Eu(III) complexes, since CPL spectroscopy is limited to luminescent species and reflects selectively toward helicity of the local structural environment around the lanthanide(III). While in comparison, exciton CD reveals the chiral structural information from the helical arrangement of the four bladed chelates. Of special importance, the observation of the highest CPL activities measured to date for lanthanide(III)–containing compounds (i.e. Eu and Sm) in solution supports that the chirality of Lanthanide(III) in the excited state corresponds to that in the ground state, which was derived from the exciton CD. PMID:22074461

  4. Testing and Characterization of CMC Combustor Liners

    NASA Technical Reports Server (NTRS)

    Robinson, R. Craig; Verrilli, Michael J.

    2003-01-01

    Multiple combustor liner applications, both segmented and fully annular designs, have been configured for exposure in NASA's High Pressure Burner Rig (HPBR). The segmented liners were attached to the rig structure with SiC/SiC fasteners and exposed to simulated gas turbine conditions for nearly 200 hours. Test conditions included pressures of 6 atm., gas velocity of 42 m/s, and gas temperatures near 1450 C. The temperatures of both the cooled and combustion flow sides of the liners were measured using optical and contact measurement techniques. Minor weight loss was observed, but the liners remained structural sound, although damage was noted in some fasteners.

  5. Effects of Liner Geometry on Acoustic Impedance

    NASA Technical Reports Server (NTRS)

    Jones, Michael G.; Tracy, Maureen B.; Watson, Willie R.; Parrott, Tony L.

    2002-01-01

    Current aircraft engine nacelles typically contain acoustic liners consisting of perforated sheets bonded onto honeycomb cavities. Numerous models have been developed to predict the acoustic impedance of these liners in the presence of grazing flow, and to use that information with aeroacoustic propagation codes to assess nacelle liner noise suppression. Recent efforts have provided advances in impedance education methodologies that offer more accurate determinations of acoustic liner properties in the presence of grazing flow. The current report provides the results of a parametric study, in which a finite element method was used to assess the effects of variations of the following geometric parameters on liner impedance, with and without the presence of grazing flow: percent open area, sheet thickness, sheet thickness-to-hole diameter ratio and cavity depth. Normal incidence acoustic impedances were determined for eight acoustic liners, consisting of punched aluminum facesheets bonded to hexcell honeycomb cavities. Similar liners were tested in the NASA Langley Research Center grazing incidence tube to determine their response in the presence of grazing flow. The resultant data provide a quantitative assessment of the effects of these perforate, single-layer liner parameters on the acoustic impedance of the liner.

  6. Internal combustion engine cylinder liner coatings

    SciTech Connect

    Yoshimitsu, T.

    1987-11-17

    In an internal combustion engine having a cylinder liner mounted in a cylinder block, the improvement is described comprising a first coating of a wear and seizure resistance material applied to the inside surface of a prescribed upper portion of the cylinder liner, and a second coating of a surface treating agent composed principally of manganous phosphate applied to the remaining inside surface of the cylinder liner. The first coating is more wear and seizure resistant than the second coating at higher temperatures to which the upper portion of the cylinder liner is subjected during engine operation than is the other portion.

  7. Polymer-cobalt(III) complexes: structural analysis of metal chelates on DNA interaction and comparative cytotoxic activity.

    PubMed

    Nehru, Selvan; Arunachalam, Sankaralingam; Arun, Renganathan; Premkumar, Kumpati

    2014-01-01

    A new series of pendant-type polymer-cobalt(III) complexes, [Co(LL)2(BPEI)Cl](2+), (where BPEI = branched polyethyleneimine, LL = dipyrido[3,2-a:2',3'-c](6,7,8,9-tetrahydro)phenazine (dpqc), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq) and imidazo[4,5-f]1,10-phenanthroline (ip)) each with three different degrees of coordination have been synthesized and characterized. Studies to know the mode and strength of interaction between these polymer-metal complexes and calf thymus DNA have been performed by UV-Visible absorption and emission techniques. Among these series, each polymer metal complex having higher binding strength with DNA has been selected to test against human cancer/normal cell lines. On the basis of these spectral studies, it is proposed that our polymer-metal complexes bind with DNA mainly through intercalation along with some electrostatic binding. The order of binding strength for the complexes with ligand, dpqc > dpq > ip. The analysis of the results suggests that polymer-cobalt(III) complexes with higher degree of coordination effectively binds with DNA due to the presence of large number of positively charged cobalt(III) chelates in the polymer chain which cooperatively act to increase the overall binding strength. These polymer-cobalt(III) complexes with hydrophobic ligands around the cobalt(III) metal centre favour the base stacking interactions via intercalation. All the complexes show very good anticancer activities and increasing of binding strength results in higher inhibition value. The polymer-cobalt(III) complex with dpqc ligand possess two fold increased anticancer activity when compared to complexes with other ligands against MCF-7 cells. Besides, the complexes were insensitive towards the growth of normal cells (HEK-293) at the IC50 concentration.

  8. Thermal Hazard Evaluation of Cumene Hydroperoxide-Metal Ion Mixture Using DSC, TAM III, and GC/MS.

    PubMed

    You, Mei-Li

    2016-04-28

    Cumene hydroperoxide (CHP) is widely used in chemical processes, mainly as an initiator for the polymerization of acrylonitrile-butadiene-styrene. It is a typical organic peroxide and an explosive substance. It is susceptible to thermal decomposition and is readily affected by contamination; moreover, it has high thermal sensitivity. The reactor tank, transit storage vessel, and pipeline used for manufacturing and transporting this substance are made of metal. Metal containers used in chemical processes can be damaged through aging, wear, erosion, and corrosion; furthermore, the containers might release metal ions. In a metal pipeline, CHP may cause incompatibility reactions because of catalyzed exothermic reactions. This paper discusses and elucidates the potential thermal hazard of a mixture of CHP and an incompatible material's metal ions. Differential scanning calorimetry (DSC) and thermal activity monitor III (TAM III) were employed to preliminarily explore and narrate the thermal hazard at the constant temperature environment. The substance was diluted and analyzed by using a gas chromatography spectrometer (GC) and gas chromatography/mass spectrometer (GC/MS) to determine the effect of thermal cracking and metal ions of CHP. The thermokinetic parameter values obtained from the experiments are discussed; the results can be used for designing an inherently safer process. As a result, the paper finds that the most hazards are in the reaction of CHP with Fe(2+). When the metal release is exothermic in advance, the system temperature increases, even leading to uncontrollable levels, and the process may slip out of control.

  9. Technique for fabrication of ultrathin foils in cylindrical geometry for liner-plasma implosion experiments with sub-megaampere currents

    DOE PAGES

    Yager-Elorriaga, D. A.; Steiner, A. M.; Patel, S. G.; ...

    2015-11-19

    In this study, we describe a technique for fabricating ultrathin foils in cylindrical geometry for liner-plasma implosion experiments using sub-MA currents. Liners are formed by wrapping a 400 nm, rectangular strip of aluminum foil around a dumbbell-shaped support structure with a non-conducting center rod, so that the liner dimensions are 1 cm in height, 6.55 mm in diameter, and 400 nm in thickness. The liner-plasmas are imploded by discharging ~600 kA with ~200 ns rise time using a 1 MA linear transformer driver, and the resulting implosions are imaged four times per shot using laser-shadowgraphy at 532 nm. As amore » result, this technique enables the study of plasma implosion physics, including the magneto Rayleigh-Taylor, sausage, and kink instabilities on initially solid, imploding metallic liners with university-scale pulsed power machines.« less

  10. Technique for fabrication of ultrathin foils in cylindrical geometry for liner-plasma implosion experiments with sub-megaampere currents

    SciTech Connect

    Yager-Elorriaga, D. A.; Steiner, A. M.; Patel, S. G.; Jordan, N. M.; Lau, Y. Y.; Gilgenbach, R. M.

    2015-11-19

    In this study, we describe a technique for fabricating ultrathin foils in cylindrical geometry for liner-plasma implosion experiments using sub-MA currents. Liners are formed by wrapping a 400 nm, rectangular strip of aluminum foil around a dumbbell-shaped support structure with a non-conducting center rod, so that the liner dimensions are 1 cm in height, 6.55 mm in diameter, and 400 nm in thickness. The liner-plasmas are imploded by discharging ~600 kA with ~200 ns rise time using a 1 MA linear transformer driver, and the resulting implosions are imaged four times per shot using laser-shadowgraphy at 532 nm. As a result, this technique enables the study of plasma implosion physics, including the magneto Rayleigh-Taylor, sausage, and kink instabilities on initially solid, imploding metallic liners with university-scale pulsed power machines.

  11. Technique for fabrication of ultrathin foils in cylindrical geometry for liner-plasma implosion experiments with sub-megaampere currents

    NASA Astrophysics Data System (ADS)

    Yager-Elorriaga, D. A.; Steiner, A. M.; Patel, S. G.; Jordan, N. M.; Lau, Y. Y.; Gilgenbach, R. M.

    2015-11-01

    In this work, we describe a technique for fabricating ultrathin foils in cylindrical geometry for liner-plasma implosion experiments using sub-MA currents. Liners are formed by wrapping a 400 nm, rectangular strip of aluminum foil around a dumbbell-shaped support structure with a non-conducting center rod, so that the liner dimensions are 1 cm in height, 6.55 mm in diameter, and 400 nm in thickness. The liner-plasmas are imploded by discharging ˜600 kA with ˜200 ns rise time using a 1 MA linear transformer driver, and the resulting implosions are imaged four times per shot using laser-shadowgraphy at 532 nm. This technique enables the study of plasma implosion physics, including the magneto Rayleigh-Taylor, sausage, and kink instabilities on initially solid, imploding metallic liners with university-scale pulsed power machines.

  12. Explosive Bonding of Refractory Metal Liners

    DTIC Science & Technology

    2004-08-01

    hardened. Mulligan et al. (2002) point out that “… commercially pure electron beam melted tantalum has an elongation of ~30 to 40% and a yield...not result in melt -induced defects destroying the bond strength. This maximum velocity, Vmax, can be calculated from the following equation: Vmax...the melting point in °C; • CB, the bulk sound speed; • K, the thermal conductivity; • C, the specific heat; • h, the flyer plate thickness; and

  13. Elastomer liners for geothermal tubulars Y267 EPDM Liner Program:

    SciTech Connect

    Hirasuna, A.R.; Davis, D.L.; Flickinger, J.E.; Stephens, C.A.

    1987-12-01

    The elastomer, Y267 EPDM, has been identified as a hydrothermally stable material which can operate at temperatures in excess of 320/sup 0/C. The goal of the Y267 Liner Program was to demonstrate the feasibility of using this material as a liner for mild steel tubulars to prevent or mitigate corrosion. If successful, the usage of EPDM lined pipe by the geothermal community may have a significant impact on operating costs and serve as a viable alternative to the use of alloyed tubulars. Tooling procedures were developed under this program to mold a 0.64 cm (0.25'') thick Y267 EPDM liner into a tubular test section 61 cm (2') in length and 19.1 cm (7.5'') in diameter (ID). A successful effort was made to identify a potential coupling agent to be used to bond the elastomer to the steel tubular wall. This agent was found to withstand the processing conditions associated with curing the elastomer at 288/sup 0/C and to retain a significant level of adhesive strength following hydrothermal testing in a synthetic brine at 260/sup 0/C for a period of 166 hours. Bonding tests were conducted on specimens of mild carbon steel and several alloys including Hastelloy C-276. An objective of the program was to field test the lined section of pipe mentioned above at a geothermal facility in the Imperial Valley. Though a test was conducted, problems encountered during the lining operation precluded an encouraging outcome. The results of the field demonstration were inconclusive. 6 refs., 13 figs., 13 tabs

  14. Progress in the Design of the Stabilized Liner Compressor for MTF/MIF Plasma Target Development

    NASA Astrophysics Data System (ADS)

    Frese, Sherry; Frese, Michael; Turchi, Peter; Gale, Don

    2016-10-01

    The Stabilized Liner Compressor (SLC) seeks to extend concepts for repetitive, rotationally stabilized, liquid-metal liners driven by free-pistons to much higher drive pressures (25 vs 5 kpsi) and faster implosion speeds (2000 vs 100 m/s) than previously demonstrated. Such extension is needed to enable experiments with magnetized-plasma targets presently offering sizes and lifetimes of 10's cm diam and 10's microsec. SLC represents the confluence of several difficult technologies, including pulsed high pressures, high-speed rotating machinery and alkali-metal (Na, NaK) handling. Solution of the two-dimensional, unsteady, compressible flow of a rotating liquid-metal liner requires advanced numerical techniques. We report the use of the 2-1/2 dimensional MHD code MACH2 to explore flow options, including magnetic flux compression, and to provide pulsed pressure distributions for mechanical design. Supported by ARPA-E ALPHA Program.

  15. From antiferromagnetic to ferromagnetic interaction in cyanido-bridged Fe(III)-Ru(II)-Fe(III) complexes by change of the central diamagnetic cyanido-metal geometry.

    PubMed

    Ma, Xiao; Hu, Sheng-Min; Tan, Chun-Hong; Zhang, Yong-Fan; Zhang, Xu-Dong; Sheng, Tian-Lu; Wu, Xin-Tao

    2013-10-07

    Cis- and trans-isomeric heterotrinuclear-metallic complexes and their two-electron-oxidation products, cis-/trans-[Cp(dppe)Fe(μ-CN)Ru(bpy)2(μ-CN)Fe(dppe)Cp][PF6]2 (cis-/trans-1[PF6]2) and cis-/trans-[Cp(dppe)Fe(μ-CN)Ru(bpy)2(μ-CN)Fe(dppe)Cp][PF6]4 (cis-/trans-1[PF6]4), have been synthesized and structurally characterized. To the best of our knowledge, the complexes are the first example of a cis-/trans-isomer with multistates. Although separated by the diamagnetic cyanido-metal bridge, the two distant paramagnetic metal centers in both the oxidized complexes exhibit quite strong magnetic couplings. As a unique example, cis-1[PF6]4 is antiferromagnetic, and trans-1[PF6]4 is ferromagnetic. Density functional theory (DFT) calculations suggest that the spin-delocalization mechanism should be responsible for the magnetic interactions between the two distant paramagnetic Fe(III) centers across the diamagnetic cyanido-metal in both cis- and trans-1(4+). Most importantly, the DFT calculations revealed that the type (antiferromagnetic or ferromagnetic) and strength (J) of the magnetic interactions in such compounds can be controlled by the variation (cis or trans) of the diamagnetic central metal configurations.

  16. Highly Efficient Cooperative Catalysis by Co III (Porphyrin) Pairs in Interpenetrating Metal-Organic Frameworks

    SciTech Connect

    Lin, Zekai; Zhang, Zhi-Ming; Chen, Yu-Sheng; Lin, Wenbin

    2016-12-02

    A series of porous twofold interpenetrated In-CoIII(porphyrin) metal–organic frameworks (MOFs) were constructed by in situ metalation of porphyrin bridging ligands and used as efficient cooperative catalysts for the hydration of terminal alkynes. The twofold interpenetrating structure brings adjacent CoIII(porphyrins) in the two networks parallel to each other with a distance of about 8.8 Å, an ideal distance for the simultaneous activation of both substrates in alkyne hydration reactions. As a result, the In-CoIII(porphyrin) MOFs exhibit much higher (up to 38 times) catalytic activity than either homogeneous catalysts or MOF controls with isolated CoIII(porphyrin) centers, thus highlighting the potential application of MOFs in cooperative catalysis.

  17. An extreme [O III] emitter at z = 3.2: a low metallicity Lyman continuum source

    NASA Astrophysics Data System (ADS)

    de Barros, S.; Vanzella, E.; Amorín, R.; Castellano, M.; Siana, B.; Grazian, A.; Suh, H.; Balestra, I.; Vignali, C.; Verhamme, A.; Zamorani, G.; Mignoli, M.; Hasinger, G.; Comastri, A.; Pentericci, L.; Pérez-Montero, E.; Fontana, A.; Giavalisco, M.; Gilli, R.

    2016-01-01

    Aims: Cosmic reionization is an important process occurring in the early epochs of the Universe. However, because of observational limitations due to the opacity of the intergalactic medium to Lyman continuum photons, the nature of ionizing sources is still not well constrained. While high-redshift star-forming galaxies are thought to be the main contributors to the ionizing background at z> 6, it is impossible to directly detect their ionizing emission. Therefore, looking at intermediate redshift analogues (z ~ 2-4) can provide useful hints about cosmic reionization. Methods: We investigate the physical properties of one of the best Lyman continuum emitter candidate at z = 3.212 found in the GOODS-S/CANDELS field with photometric coverage from the U to the MIPS 24 μm band and VIMOS/VLT and MOSFIRE/Keck spectroscopy. These observations allow us to derive physical properties such as stellar mass, star formation rate, age of the stellar population, dust attenuation, metallicity, and ionization parameter, and to determine how these parameters are related to the Lyman continuum emission. Results: Investigation of the UV spectrum confirms a direct spectroscopic detection of the Lyman continuum emission with S/N> 5. Non-zero Lyα flux at the systemic redshift and high Lyman-α escape fraction (fesc(Lyα) ≥ 0.78) suggest a low H i column density. The weak C and Si low-ionization absorption lines are also consistent with a low covering fraction along the line of sight. The subsolar abundances are consistent with a young and extreme starburst. The [O iii]λλ4959,5007+Hβ equivalent width (EW) is one of the largest reported for a galaxy at z> 3 (EW( [ O iii ] λλ4959,5007 + Hβ) ≃ 1600 Å, rest-frame; 6700 Å observed-frame) and the near-infrared spectrum shows that this is mainly due to an extremely strong [O iii] emission. The large observed [O iii]/[O ii] ratio (>10) and high ionization parameter are consistent with prediction from photoionization models in the

  18. Mechanistic aspects of metal valence change in SalenCo(III)OAc-catalyzed hydrolytic kinetic resolution of racemic epoxides.

    PubMed

    Ren, Wei-Min; Wang, Yi-Ming; Zhang, Rong; Jiang, Jing-Yang; Lu, Xiao-Bing

    2013-05-17

    The chiral SalenCo(III)OAc-catalyzed hydrolytic kinetic resolution (HKR) of racemic terminal epoxides to afford both enantioenriched epoxides and diols presents one of the most important achievements in asymmetric synthesis chemistry. Previous studies mainly focused on the development of highly efficient catalysts, while rare reports concerned the mechanistic understanding of metal valence change, associated with the formation of inactive Co(II)-Salen complex. Herein, we report the mechanistic aspects of catalyst deactivation regarding the transformation of Co(III) to Co(II) derivative in the HKR of racemic epoxides catalyzed by SalenCo(III)OAc complexes with an appended 1,5,7-triazabicyclo[4.4.0]dec-5-ene on the ligand framework by means of electrospray ionization mass spectrometry (ESI-MS). Continuous determination of transient cationic species in ESI-MS positive mode in conjunction with UV-vis spectroscopic studies at various time points provides evidence that a certain amount of SalenCo(III)OAc molecules were reduced to the corresponding Co(II) derivatives in the HKR of racemic propylene oxide or styrene oxide. To be accompanied by the reduction of Co(III) to Co(II), the resultant diols were oxidized to α-hydroxy ketones. These analyses along with some control experiments gave a mechanistic understanding of catalyst deactivation of SalenCo(III)OAc-catalyzed HKR of racemic epoxides regarding an unveiled redox reaction between Co(III)-Salen and diol, the hydrolyzed product.

  19. Three new europium(III) methanetriacetate metal-organic frameworks: the influence of synthesis on the product topology.

    PubMed

    Cañadillas-Delgado, Laura; Fabelo, Oscar; Pasán, Jorge; Déniz, Mariadel; Martínez-Benito, Carla; Díaz-Gallifa, Pau; Martín, Tomás; Ruiz-Pérez, Catalina

    2014-02-01

    Three new metal-organic framework structures containing Eu(III) and the little explored methanetriacetate (C7H7O6(3-), mta(3-)) ligand have been synthesized. Gel synthesis yields a two-dimensional framework with the formula [Eu(mta)(H2O)3]n·2nH2O, (I), while two polymorphs of the three-dimensional framework material [Eu(mta)(H2O)]n·nH2O, (II) and (III), are obtained through hydrothermal synthesis at either 423 or 443 K. Compounds (I) and (II) are isomorphous with previously reported Gd(III) compounds, but compound (III) constitutes a new phase. Compound (I) can be described in terms of dinuclear [Eu2(H2O)4](6+) units bonded through mta(3-) ligands to form a two-dimensional framework with topology corresponding to a (6,3)-connected binodal (4(3))(4(6)6(6)8(3))-kgd net, where the dinuclear [Eu2(H2O)4](6+) units are considered as a single node. Compounds (II) and (III) have distinct three-dimensional topologies, namely a (4(12)6(3))(4(9)6(6))-nia net for (II) and a (4(10)6(5))(4(11)6(4))-K2O2; 36641 net for (III). The crystal density of (III) is greater than that of (II), consistent with the increase of temperature, and thereby autogeneous pressure, in the hydrothermal synthesis.

  20. Liner Compression of a MAGO / Inverse-Pinch Configuration

    SciTech Connect

    Siemon, R E; Atchison, W L; Awe, T; Bauer, B S; Buyko, A M; Chernyshev, V K; Cowan, T E; Degnan, J H; Faehl, R J; Fuelling, S; Garanin, S F; Goodrich, T; Ivanovsky, A V; Lindemuth, I R; Makhin, V; Mokhov, V N; Reinovsky, R E; Ryutov, D D; Scudder, D W; Taylor, T; Yakubov, V B

    2005-05-18

    In the ''metal liner'' approach to Magnetized Target Fusion (MTF), a preheated magnetized plasma target is compressed to thermonuclear temperature and high density by externally driving the implosion of a flux conserving metal enclosure, or liner, which contains the plasma target. As in inertial confinement fusion, the principle fusion fuel heating mechanism is pdV work by the imploding enclosure, called a pusher in ICF. One possible MTF target, the hard-core diffuse z pinch, has been studied in MAGO experiments at VNIIEF, and is one possible target being considered for experiments on the Atlas pulsed power facility. Numerical MHD simulations show two intriguing and helpful features of the diffuse z pinch with respect to compressional heating. First, in two-dimensional simulations the m=0 interchange modes, arising from an unstable pressure profile, result in turbulent motions and self-organization into a stable pressure profile. The turbulence also gives rise to convective thermal transport, but the level of turbulence saturates at a finite level, and simulations show substantial heating during liner compression despite the turbulence. The second helpful feature is that pressure profile evolution during compression tends towards improved stability rather than instability when analyzed according to the Kadomtsev criteria. A liner experiment is planned for Atlas to study compression of magnetic flux without plasma as a first step. The Atlas geometry is compatible with a diffuse z pinch, and simulations of possible future experiments show that keV temperatures and useful neutron production for diagnostic purposes should be possible if a suitable plasma injector is added to the Atlas facility.

  1. Determination of Chromium(III), Chromium(VI), and Chromium(III) acetylacetonate in water by ion-exchange disk extraction/metal furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Kamakura, Nao; Inui, Tetsuo; Kitano, Masaru; Nakamura, Toshihiro

    A new method for the separate determination of Chromium(III) (Cr(III)), Chromium(VI) (Cr(VI)), and Cr(III) acetylacetonate (Cr(acac)3) in water was developed using a cation-exchange extraction disk (CED) and an anion-exchange extraction disk (AED) combined with metal furnace atomic absorption spectrometry (MFAAS). A 100-mL water sample was adjusted to pH 5.6 and passed through the CED placed on the AED. Cr(acac)3 and Cr(III) were adsorbed on the CED, and Cr(VI) was adsorbed on the AED. The adsorbed Cr(acac)3 was eluted with 50 mL of carbon tetrachloride, followed by the elution of Cr(III) with 50 mL of 3 mol L- 1 nitric acid. Cr(VI) was eluted with 50 mL of 3 mol L- 1 nitric acid. The chemical species of Cr eluted from the CED with carbon tetrachloride was identified as Cr(acac)3 using infrared spectroscopy. The eluate of Cr(acac)3 was diluted to 100 mL with carbon tetrachloride, and those of Cr(III) and Cr(VI) were diluted to 100 mL with deionized water. All of the solutions were subsequently analyzed by MFAAS. The calibration curve for the Cr(acac)3 aqueous solutions exhibited good linearity in the range of 0.1 to 1 ng. The detection limit of Cr, which corresponded to three times the standard deviation (n = 10) of the blank values, was 20 pg. The recovery test for Cr(III), Cr(VI), and Cr(acac)3 exhibited desirable results (96.0%-107%) when 5 μg of each species (50 μg L- 1) was added to 100 mL water samples (i.e., tap water, rainwater, and bottled drinking water). In a humic acid solution, Cr(acac)3 was quantitatively recovered (103%), but Cr(III) and Cr(VI) exhibited poor recoveries (i.e., 84.8% and 78.4%, respectively).

  2. Do Changes in the Production Process Affect the Outcome of Ceramic Liners: A 3-Year Follow-Up Study.

    PubMed

    Schmidt-Braekling, Tom; Renner, Lisa; Mintz, Douglas N; Waldstein, Wenzel; Endo, Yoshimi; Boettner, Friedrich

    2017-04-01

    In 2011, the current liner was withdrawn from the market because of the potential risk for liner fracture secondary to increased pressures used to assemble the metal locking ring. The present study provides a short-term follow-up of patients with this implant. We retrospectively evaluated 63 consecutive hips in 53 patients operated by a single surgeon using a recalled ceramic-on-ceramic bearing. There were 30 women and 23 men with an average age of 50.6 years (range 20.3-63.5 years). The mean follow-up was 36.8 months. Six hips in 6 patients were revised (9.5%) because of a liner-fracture during the follow-up period. All liner fractures were identified on computer tomography imaging. Nine patients had self-reported episodes of squeaking (14.3%). All 6 patients that underwent revision surgery for liner fracture described squeaking before revision. There were no revisions for other causes. Two of the revised patients had a subsequent dislocation (33%). The recalled ceramic liner lots have an increased liner fracture rate. Patients with mechanical symptoms or squeaking should undergo computer tomography to rule out liner facture. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Effect of metal ion Fe(III) on the performance of chlorophyll as photosensitizers on dye sensitized solar cell

    NASA Astrophysics Data System (ADS)

    Setyawati, Harsasi; Darmokoesoemo, Handoko; Ningtyas, Anggy Tamara Ayu; Kadmi, Yassine; Elmsellem, Hicham; Kusuma, Heri Septya

    The energy crisis is a major problem facing the world today and will need a renewable energy source that is environmentally friendly; one of these is the dye sensitized solar cell (DSSC). DSSC is photochemical electric cell that can convert solar energy into electrical energy. This research aims to study the characteristics of chlorophyll compounds with the addition of metal ions Fe(III) and to determine the effect of Fe(III) on the performance of chlorophyll as a photosensitizer in the DSSC. The formation of complex compounds of Fe(III)-chlorophyll is shown by the phenomenon of metal ligand charge transfer (MLCT) at a wavelength of 263.00 nm and absorption transition d-d at 745.00 nm. Fourier transform infrared characterization of the binding of Fe-O complex compounds appears at 486.06 cm-1. The complex compound of Fe(III)-chlorophyll has a magnetic moment value of 9.62 Bohr Magneton (BM). The existence of ion Fe(III) in chlorophyll can improve the performance of chlorophyll as a dye sensitizer with a maximum current of 4.00 mA/cm2, maximum voltage of 0.18 volts and efficiency values of 1.35%.

  4. Mechanical downsizing of a gadolinium(III)-based metal-organic framework for anticancer drug delivery.

    PubMed

    Kundu, Tanay; Mitra, Shouvik; Patra, Prasun; Goswami, Arunava; Díaz Díaz, David; Banerjee, Rahul

    2014-08-11

    A Gd(III) -based porous metal-organic framework (MOF), Gd-pDBI, has been synthesized using fluorescent linker pDBI (pDBI=(1,4-bis(5-carboxy-1H-benzimidazole-2-yl)benzene)), resulting in a three-dimensional interpenetrated structure with a one-dimensional open channel (1.9×1.2 nm) filled with hydrogen-bonded water assemblies. Gd-pDBI exhibits high thermal stability, porosity, excellent water stability, along with organic-solvent and mild acid and base stability with retention of crystallinity. Gd-pDBI was transformed to the nanoscale regime (ca. 140 nm) by mechanical grinding to yield MG-Gd-pDBI with excellent water dispersibility (>90 min), maintaining its porosity and crystallinity. In vitro and in vivo studies on MG-Gd-pDBI revealed its low blood toxicity and highest drug loading (12 wt %) of anticancer drug doxorubicin in MOFs reported to date with pH-responsive cancer-cell-specific drug release.

  5. Large Engine Technology Program. Task 21: Rich Burn Liner for Near Term Experimental Evaluations

    NASA Technical Reports Server (NTRS)

    Hautman, D. J.; Padget, F. C.; Kwoka, D.; Siskind, K. S.; Lohmann, R. P.

    2005-01-01

    The objective of the task reported herein, which was conducted as part of the NASA sponsored Large Engine Technology program, was to define and evaluate a near-term rich-zone liner construction based on currently available materials and fabrication processes for a Rich-Quench-Lean combustor. This liner must be capable of operation at the temperatures and pressures of simulated HSCT flight conditions but only needs sufficient durability for limited duration testing in combustor rigs and demonstrator engines in the near future. This must be achieved at realistic cooling airflow rates since the approach must not compromise the emissions, performance, and operability of the test combustors, relative to the product engine goals. The effort was initiated with an analytical screening of three different liner construction concepts. These included a full cylinder metallic liner and one with multiple segments of monolithic ceramic, both of which incorporated convective cooling on the external surface using combustor airflow that bypassed the rich zone. The third approach was a metallic platelet construction with internal convective cooling. These three metal liner/jacket combinations were tested in a modified version of an existing Rich-Quench-Lean combustor rig to obtain data for heat transfer model refinement and durability verification.

  6. Fabrication of a Kevlar liner assembly

    SciTech Connect

    Schloman, A.H.

    1980-07-01

    Several liner assemblies were fabricated with Kevlar 49 and epoxy using various wet layup and prepreg processes. A production process, using prepreg material, was developed for fabricating the liner and a wet layup molding process was used to fabricate the Kevlar hat-shaped tunnels. Fabrication of the tunnels using Kevlar prepreg with an autoclave curving process was evaluated.

  7. HYDRAULIC CONDUCTIVITY OF THREE GEOSYNTHETIC CLAY LINERS

    EPA Science Inventory

    The hydraulic conductivity of three 2.9 m2 (32 sq ft) geosynthetic clay liners (GCLs) was measured. Tests were performed on individual sheets of the GCLs, on overlapped pieces of GCLs, and on composite liners consisting of a punctured geomembrane overlying a GCL. Hyd...

  8. Liquid-cooled liner for helmets

    NASA Technical Reports Server (NTRS)

    Williams, B. A.; Elkins, W.

    1974-01-01

    Liner acts as coolant tubing, manifold, and supporting structures. Fabric of waffle-design is made of several integrated channels (or capillaries) through which coolant liquid can flow. Thin and light-weight liner can be incorporated into any type of helmet or head gear.

  9. HYDRAULIC CONDUCTIVITY OF THREE GEOSYNTHETIC CLAY LINERS

    EPA Science Inventory

    The hydraulic conductivity of three 2.9 m2 (32 sq ft) geosynthetic clay liners (GCLs) was measured. Tests were performed on individual sheets of the GCLs, on overlapped pieces of GCLs, and on composite liners consisting of a punctured geomembrane overlying a GCL. Hyd...

  10. Shock wave absorber having a deformable liner

    DOEpatents

    Youngdahl, C.K.; Wiedermann, A.H.; Shin, Y.W.; Kot, C.A.; Ockert, C.E.

    1983-08-26

    This invention discloses a shock wave absorber for a piping system carrying liquid. The absorber has a plastically deformable liner defining the normal flow boundary for an axial segment of the piping system, and a nondeformable housing is spaced outwardly from the liner so as to define a gas-tight space therebetween. The flow capacity of the liner generally corresponds to the flow capacity of the piping system line, but the liner has a noncircular cross section and extends axially of the piping system line a distance between one and twenty times the diameter thereof. Gas pressurizes the gas-tight space equal to the normal liquid pressure in the piping system. The liner has sufficient structural capacity to withstand between one and one-half and two times this normal liquid pressures; but at greater pressures it begins to plastically deform initially with respect to shape to a more circular cross section, and then with respect to material extension by circumferentially stretching the wall of the liner. A high energy shock wave passing through the liner thus plastically deforms the liner radially into the gas space and progressively also as needed in the axial direction of the shock wave to minimize transmission of the shock wave beyond the absorber.

  11. Sorption Kinetics Of Selected Heavy Metals Adsorption To Natural And Fe(III) Modified Zeolite Tuff Containing Clinoptilolite Mineral

    NASA Astrophysics Data System (ADS)

    Sirotiak, Maroš; Lipovský, Marek; Bartošová, Alica

    2015-06-01

    In the research described in this paper, studied was sorption capacity of natural and ferric modification of zeolite tuff containing mineral clinoptilolite from the Nižný Hrabovec deposit to remove potentially toxic metals (ionic forms of chromium, nickel, copper and aluminium) from their water solutions. We reported that the Fe (III) zeolite has an enhanced ability to sorption of Cu (II), and a slight improvement occurs in the case of Cr (VI) and Ni (II). On the other hand, the deterioration was observed in the case of Al (III) adsorption.

  12. On the formation of aliphatic polycarbonates from epoxides with chromium(III) and aluminum(III) metal-salen complexes.

    PubMed

    Luinstra, Gerrit A; Haas, Gerhard R; Molnar, Ferenc; Bernhart, Volker; Eberhardt, Robert; Rieger, Bernhard

    2005-10-21

    A DFT-based description is given of the CO2/epoxide copolymerization with a catalyst system consisting of metal (chromium, iron, titanium, aluminum)-salen complexes (salen = N,N'-bis(3,5-di-tert-butylsalicyliden-1,6-diaminophenyl) in combination with either chloride, acetate, or dimethylamino pyridine (DMAP) as external nucleophile. Calculations indicate that initiation proceeds through nucleophilic attack at a metal-coordinated epoxide, and the most likely propagation reaction is a bimolecular process in which a metal-bound nucleophile attacks a metal-bound epoxide. Carbon dioxide insertion occurs at a single metal center and is most likely the rate-determining step at low pressure. The prevalent chain terminating/degradation-the so-called backbiting, a reaction leading to formation of cyclic carbonate from the polymer chain-would involve attack of a carbonate nucleophile rather than an alkoxide at the last unit of the growing chain. The backbiting of a free carbonato chain end is particularly efficient. Anion dissociation from six-coordinate aluminum is appreciably easier than from chromium-salen complexes, indicating the reason why in the former case cyclic carbonate is the sole product. Experimental data were gathered for a series of chromium-, aluminum-, iron-, and zinc-salen complexes, which were used in combination with external nucleophiles like DMAP and mainly (tetraalkyl ammonium) chloride/acetate. Aluminum complexes transform PO (propylene oxide) and CO2 to give exclusively propylene carbonate. This is explained by rapid carbonate anion dissociation from a six-coordinate complex and cyclic formation. CO2 insertion or nucleophilic attack of an external nucleophile at a coordinated epoxide (at higher CO2 pressure) are the rate-determining steps. Catalysis with [Cr(salen)(acetate/chloride)] complexes leads to the formation of both cyclic carbonate and polypropylene carbonate with various quantities of ether linkages. The dependence of the activity and

  13. Late failure of annealed highly cross-linked polyethylene acetabular liner.

    PubMed

    Hara, Daisuke; Nakashima, Yasuharu; Yamamoto, Takuaki; Higashihara, Shinshichiro; Todo, Mitsugu; Hirata, Masanobu; Akiyama, Mio; Iwamoto, Yukihide

    2013-12-01

    Highly cross-linked polyethylene (HXPE) in total hip arthroplasty (THA) has been shown to significantly decrease wear rates compared with conventional polyethylene (CPE). However, crosslinking, thermal treatment and oxidation can decrease the mechanical properties of PE, and several cases of fracture of remelted HXPE liners were reported. We present, for the first time, unexpected failures of THA with the use of annealed HXPE liners in two patients occurring at 7 and 8 years after operation. Operative findings revealed dislocated liners from the metal shell and a fracture of the superior rim at the rim-dome junction in both liners. Scanning electron microscopy showed that the cracks initiated at the rim and propagated toward the articular surface. Both liners showed generally a low amount of oxidation (less than 1.00) at the articular surface and low wear rates; however, oxidation at the rim was relatively higher (mean 1.55). These findings suggested that decreased mechanical properties at the rim-dome junction due to cross-linking, annealing and oxidation might have been caused breakage of the HXPE liners after a long implantation time, although the annealed HXPE achieved low degree of wear.

  14. Utilization of sepiolite materials as a bottom liner material in solid waste landfills.

    PubMed

    Guney, Yucel; Cetin, Bora; Aydilek, Ahmet H; Tanyu, Burak F; Koparal, Savas

    2014-01-01

    Landfill bottom liners are generally constructed with natural clay soils due to their high strength and low hydraulic conductivity characteristics. However, in recent years it is increasingly difficult to find locally available clay soils that satisfy the required engineering properties. Fine grained soils such as sepiolite and zeolite may be used as alternative materials in the constructions of landfill bottom liners. A study was conducted to investigate the feasibility of using natural clay rich in kaolinite, sepiolite, zeolite, and their mixtures as a bottom liner material. Unconfined compression tests, swell tests, hydraulic conductivity tests, batch and column adsorption tests were performed on each type of soil and sepiolite-zeolite mixtures. The results of the current study indicate that sepiolite is the dominant material that affects both the geomechanical and geoenvironmental properties of these alternative liners. An increase in sepiolite content in the sepiolite-zeolite mixtures increased the strength, swelling potential and metal adsorption capacities of the soil mixtures. Moreover, hydraulic conductivity of the mixtures decreased significantly with the addition of sepiolite. The utilization of sepiolite-zeolite materials as a bottom liner material allowed for thinner liners with some reduction in construction costs compared to use of a kaolinite-rich clay. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Stabilized Liner Compressor: The Return of Linus

    NASA Astrophysics Data System (ADS)

    Turchi, Peter; Frese, Sherry; Frese, Michael; Mielke, Charles; Hinrichs, Mark; Nguyen, Doan

    2015-11-01

    To access the lower cost regime of magneto-inertial fusion at megagauss magnetic field-levels requires the use of dynamic conductors in the form of imploding cylindrical shells, aka, liners. Such liner implosions can compress magnetic flux and plasma to attain fusion conditions, but are subject to Rayleigh-Taylor instabilities, both in the launch and recovery of the liner material and in the final few diameters of implosion. These instabilities were overcome in the Linus program at the Naval Research Laboratory, c. 1979, providing the experimentally-demonstrated basis for repetitive operation and leading to an economical reactor concept at low fusion gain. The recent ARPA-E program for low-cost fusion technology has revived interest in this approach. We shall discuss progress in modeling and design of a Stabilized Liner Compressor (SLC) that extends the earlier work to higher pressures and liner speeds appropriate to potential plasma targets. Sponsored by ARPA-E ALPHA Program.

  16. Water movement through an experimental soil liner

    USGS Publications Warehouse

    Krapac, I.G.; Cartwright, K.; Panno, S.V.; Hensel, B.R.; Rehfeldt, K.R.; Herzog, B.L.

    1991-01-01

    A field-scale soil liner was constructed to test whether compacted soil barriers in cover and liner systems could be built to meet the U.S. EPA saturated hydraulic conductivity requirement (???1 x 10-7 cm s-1). The 8 x 15 x 0.9m liner was constructed in 15 cm compacted lifts using a 20,037 kg pad-foot compactor and standard engineering practices. Water infiltration into the liner has been monitored for one year. Monitoring will continue until water break through at the base of the liner occurs. Estimated saturated hydraulic conductivities were 2.5 x 10-9, 4.0 x 10-8, and 5.0 x 10-8 cm s-1 based on measurements of water infiltration into the liner by large- and small-ring infiltrometers and a water balance analysis, respectively. Also investigated in this research was the variability of the liner's hydraulic properties and estimates of the transit times for water and tracers. Small variances exhibited by small-ring flux data suggested that the liner was homogeneous with respect to infiltration fluxes. The predictions of water and tracer breakthrough at the base of the liner ranged from 2.4-12.6 y, depending on the method of calculation and assumptions made. The liner appeared to be saturated to a depth between 18 and 33 cm at the end of the first year of monitoring. Transit time calculations cannot be verified yet, since breakthrough has not occurred. The work conducted so far indicates that compacted soil barriers can be constructed to meet the saturated hydraulic conductivity requirement established by the U.S. EPA.A field-scale soil liner was constructed to test whether compacted soil barriers in cover and liner systems could be built to meet the U.S. EPA saturated hydraulic conductivity requirement (??? 1 ?? 10-7 cm s-1). The 8 ?? 15 ?? 0.9 m liner was constructed in 15 cm compacted lifts using a 20.037 kg pad-foot compactor and standard engineering practices. Water infiltration into the liner has been monitored for one year. Monitoring will continue until water

  17. Solution structure of a metal-binding site in the major groove of RNA complexed with cobalt (III) hexammine.

    PubMed

    Kieft, J S; Tinoco, I

    1997-05-15

    Solvated metal ions are critical for the proper folding and function of RNA. Despite the importance of these ions, the details of specific metal ion-RNA interactions are poorly understood. The crystal structure of a group I intron ribozyme domain characterized several metal-binding sites in the RNA with osmium (III) hexammine bound in the major groove. A corresponding method for locating and characterizing metal-binding sites of RNA in solution is of obvious interest. NMR should be ideal for localizing metal hexammine ions bound to the RNA because of the large concentration of protons around the metal center. We have solved the solution structure of the P5b stem loop from a group I intron ribozyme bound to a cobalt (III) hexammine ion. The location of the ion is precisely determined by intermolecular nuclear Overhausser effect cross-peaks between the cobalt (III) hexammine protons and both exchangeable and non-exchangeable RNA protons in the major groove. The binding site consists of tandem G-U base pairs in a sequence of four consecutive G residues ending in a GAAA tetraloop, as originally identified in the crystal structure. The edges of the bases in the major groove present an electrostatically negative face and a variety of hydrogen-bond acceptors for the cobalt (III) hexammine ion. The metal ion ligand is bound near the guanosine nucleotides of the adjacent G-U base pairs, where it makes hydrogen bonds with the N7 and carbonyl groups of both guanines. The carbonyl groups of the uracil residues add to the negative surface of the binding pocket, but do not form hydrogen bonds with the hexammine. Additional hydrogen bonds form with other guanine residues of the GGGG sequence. The structure of the binding site does not change significantly on binding the cobalt (III) hexammine. The structure of the complex in solution is very similar to the structure in the crystal. The structure presents a picture of how tandem G-U base pairs bind and position metal ions within

  18. NGC 5252 - a Liner undercover

    NASA Astrophysics Data System (ADS)

    Goncalves, A. C.; Veron, P.; Veron-Cetty, M.-P.

    1998-05-01

    Ground based long slit spectroscopic observations of the nuclear region of NGC 5252, and Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) spectra of the nucleus and two bright knots located 0.36'' NE and 0.31'' SW from it, show that the nuclear region exhibits the characteristics of a Liner with exceptionally strong [O i] emission, all lines being broad (FWHM ~ 1100kms(-1) ), while the gas outside the nucleus has a typical Seyfert 2 spectrum with relatively narrow lines ( ~ 200-300kms(-1) ). We suggest that all the emitting gas is photoionized by the hidden non-thermal nuclear source detected through near-infrared (Kotilainen & Prieto 1995) and X-ray (Cappi et al. 1996) observations, the ionizing continuum, in the case of the central Liner, being ``filtered'' by a matter-bounded highly ionized cloud, hidden from our view by the same material obscuring the central continuum source. Based on observations collected at the Observatoire de Haute-Provence (CNRS, France) and Hubble Space Telescope data obtained from the Space Telescope European Coordinating Facility (ST-ECF) Archive.

  19. Reduction of Cr(VI) to Cr(III) by wetland plants: Potential for in situ heavy metal detoxification

    SciTech Connect

    Lytle, C.M.; Qian, J.H.; Hansen, D.; Zayed, A.; Terry, N.; Lytle, F.W.; Yang, N.

    1998-10-15

    Reduction of heavy metals in situ by plants may be a useful detoxification mechanism for phytoremediation. Using X-ray spectroscopy, the authors show that Eichhornia crassipes (water hyacinth), supplied with Cr(VI) in nutrient culture, accumulated nontoxic Cr(III) in root and shoot tissues. The reduction of Cr(VI) to Cr(III) appeared to occur in the fine lateral roots. The Cr(III) was subsequently translocated to leaf tissues. Extended X-ray absorption fine structure of Cr in leaf and petiole differed when compared to Cr in roots. In roots, Cr(III) was hydrated by water, but in petiole and more so in leaf, a portion of the Cr(III) may be bound to oxalate ligands. This suggests that E. crassipes detoxified Cr(VI) upon root uptake and transported a portion of the detoxified Cr to leaf tissues. Cr-rich crystalline structures were observed on the leaf surface. The chemical species of Cr in other plants, collected from wetlands that contained Cr(VI)-contaminated wastewater, was also found to be Cr(III). The authors propose that this plant-based reduction of Cr(VI) by E. crassipes has the potential to be used for the in situ detoxification of Cr(VI)-contaminated wastestreams.

  20. Liners of natural porous materials to minimize pollutant migration. Final report, Oct. 1975 - Sep. 1977

    SciTech Connect

    Fuller, W.H.

    1981-07-01

    The use of natural low-cost materials as barriers for minimizing pollution migration out of landfills by retaining contaminants from liquids was investigated. The relative effectiveness of natural low-cost liners of crushed limestone, clayey soil, hydrous oxides of iron, and crushed pecan hulls for minimizing the migration of Be, Cd, Cr, Fe, Ni, Zn, and total organic carbon constituents of municipal solid waste landfill leachates was evaluated. Several leachate variables such as aqueous dilution, aeration, pH, and flux were also studied for their effect on movement of metals through 11 representative U.S. soils. Laboratory investigations using soil columns as a first step in screening for potential liners and manipulation practices are described. Limestone and hydrous iron oxide were found to be potentially useful as porous liners for retention of metallic leachate constituents. The amounts of these materials in natural soil were also found to be useful predictors of contaminant removal.

  1. Bis-Tridentate Ir(III) Metal Phosphors for Efficient Deep-Blue Organic Light-Emitting Diodes.

    PubMed

    Kuo, Hsin-Hung; Chen, Yi-Ting; Devereux, Leon R; Wu, Chung-Chih; Fox, Mark A; Kuei, Chu-Yun; Chi, Yun; Lee, Gene-Hsiang

    2017-09-01

    Emissive Ir(III) metal complexes possessing two tridentate chelates (bis-tridentate) are known to be more robust compared to those with three bidentate chelates (tris-bidentate). Here, the deep-blue-emitting, bis-tridentate Ir(III) metal phosphors bearing both the dicarbene pincer ancillary such as 2,6-diimidazolylidene benzene and the 6-pyrazolyl-2-phenoxylpyridine chromophoric chelate are synthesized. A deep-blue organic light-emitting diode from one phosphor exhibits Commission Internationale de l'Eclairage (CIE(x,y) ) coordinates of (0.15, 0.17) with maximum external quantum efficiency (max. EQE) of 20.7% and EQE = 14.6% at the practical brightness of 100 cd m(-2) . © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Filament wound pressure vessels - Effects of using liner tooling of low pressure vessels for high pressure vessels development

    NASA Astrophysics Data System (ADS)

    Lal, Krishna M.

    High performance pressure vessels have been recently demanded for aerospace and defense applications. Filament wound pressure vessels consist of a metallic thin liner, which also acts as a mandrel, and composite/epoxy overwrap. Graphite/epoxy overwrapped vessels have been developed to obtain the performance ratio, PV/W, as high as one million inches. Under very high pressure the isotropic metallic liner deforms elasto-plastically, and orthotropic composite fibers deform elastically. Sometimes, for the development of ultra high pressure vessels, composite pressure vessels industry uses the existing liner tooling developed for low burst pressure capacity composite vessels. This work presents the effects of various design variables including the low pressure liner tooling for the development of the high burst pressure capacity Brilliant Pebbles helium tanks. Advance stress analysis and development of an ultra high pressure helium tank.

  3. Assessing bioavailability levels of metals in effluent-affected rivers: effect of Fe(III) and chelating agents on the distribution of metal speciation.

    PubMed

    Han, Shuping; Naito, Wataru; Masunaga, Shigeki

    To assess the effects of Fe(III) and anthropogenic ligands on the bioavailability of Ni, Cu, Zn, and Pb, concentrations of bioavailable metals were measured by the DGT (diffusive gradients in thin films) method in some urban rivers, and were compared with concentrations calculated by a chemical equilibrium model (WHAM 7.0). Assuming that dissolved Fe(III) (<0.45 μm membrane filtered) was in equilibrium with colloidal iron oxide, the WHAM 7.0 model estimated that bioavailable concentrations of Ni, Cu, and Zn were slightly higher than the corresponding values estimated assuming that dissolved Fe(III) was absent. In contrast, lower levels of free Pb were predicted by the WHAM 7.0 model when dissolved Fe(III) was included. Estimates showed that most of the dissolved Pb was present as colloidal iron-Pb complex. Ethylene-diamine-tetra-acetic acid (EDTA) concentrations at sampling sites were predicted from the relationship between EDTA and the calculated bioavailable concentration of Zn. When both colloidal iron and predicted EDTA concentrations were included in the WHAM 7.0 calculations, dissolved metals showed a strong tendency to form EDTA complexes, in the order Ni > Cu > Zn > Pb. With the inclusion of EDTA, bioavailable concentrations of Ni, Cu, and Zn predicted by WHAM 7.0 were different from those predicted considering only humic substances and colloidal iron.

  4. Dipolar Excitations at the L{sub III} X-Ray Absorption Edges of the Heavy Rare-Earth Metals

    SciTech Connect

    Brown, S. D.; Bouchenoire, L.; Thompson, P. B. J.; Mannix, D.; Strange, P.; Zarychta, B.; Stockton, S. J.; Horne, M.; Arola, E.; Ebert, H.; Fort, D.

    2007-12-14

    We report measured dipolar asymmetry ratios at the L{sub III} edges of the heavy rare-earth metals. The results are compared with a first-principles calculation and excellent agreement is found. A simple model of the scattering is developed, enabling us to reinterpret the resonant x-ray scattering in these materials and to identify the peaks in the asymmetry ratios with features in the spin and orbital moment densities.

  5. [Short-term effects on reconstruction of Paprosky type III severe acetabulum bone defect with tantalum metal block].

    PubMed

    Tang, Zhong-yao; Li, Peng; Cha, Xiao-feng

    2015-12-01

    To investigate methods and short-term effects on tantalum metal block for reconstruction of Paprosky type III severe acetabulum bone defect. Twelve patients (12 hips) with Paprosky type III severe acetabulum bone defect,treated with tantalum metal block in revision of total hip arthroplasty, were retrospectively analyzed from March 2009 to December 2012. Among the patients, there were 5 males and 7 females aged from 45 to 78 years old with an average of 64 years old; the courses of disease ranged from 3 to 32 months with an average of 16 months. According to classification of Paprosky, all patients were Paprosky type III acetabulum bone defect. All patients were used tantalum metal block in revision of total hip arthroplasty, and large diameter biological acetabulum cups were used in combination. Operative time,blood loss and postoperative complications were recorded and compared, Harris score were used to evaluate clinical effects. Eleven patients ( 11 hips) were followed up from 9 to 36 months with an average of 25 months, 1 case was lost to follow-up for dying in car accident. The incisions were healed at stage I . Operative time ranged from 2 to 6 h with an average of 3 h; blood loss was 300 to 1 600 ml with an average of 900 ml. No deep venous thrombosis, periprosthetic femoral fracture and infection, sciatic nerve injury occurred after operation. Harris score were improved from (46.25 ± 8.99) before operation to (83.75 ± 6.76) after operation. There was significant difference in Harris score before and after operation (t = 3.14, P = 0.00 < 0.05), and 7 cases got excellent results, 2 good and 2 moderate. CONCLUCSION: Tantalum metal block is suitable for revision of Paprosky III acetabulum bone defect, could repair different kinds of acetabulum cup defect, could fill up inclusive defect of inner wall combined with particulate bone graft, induce bone growth pressured between metal block and metal cup, provide a new further choose for the treatment of Paprosky

  6. Group III alcohol dehydrogenase from Pectobacterium atrosepticum: insights into enzymatic activity and organization of the metal ion-containing region.

    PubMed

    Elleuche, Skander; Fodor, Krisztian; von der Heyde, Amélie; Klippel, Barbara; Wilmanns, Matthias; Antranikian, Garabed

    2014-05-01

    NAD(P)(+)-dependent alcohol dehydrogenases (ADH) are widely distributed in all phyla. These proteins can be assigned to three nonhomologous groups of isozymes, with group III being highly diverse with regards to catalytic activity and primary structure. Members of group III ADHs share a conserved stretch of amino acid residues important for cofactor binding and metal ion coordination, while sequence identities for complete proteins are highly diverse (<20 to >90 %). A putative group III ADH PaYqhD has been identified in BLAST analysis from the plant pathogenic enterobacterium Pectobacterium atrosepticum. The PaYqhD gene was expressed in the heterologous host Escherichia coli, and the recombinant protein was purified in a two-step purification procedure to homogeneity indicating an obligate dimerization of monomers. Four conserved amino acid residues involved in metal ion coordination were substituted with alanine, and their importance for catalytic activity was confirmed by circular dichroism spectrum determination, in vitro, and growth experiments. PaYqhD exhibits optimal activity at 40 °C with short carbon chain aldehyde compounds and NADPH as cofactor indicating the enzyme to be an aldehyde reductase. No oxidative activities towards alcoholic compounds were detectable. EDTA completely inhibited catalytic activity and was fully restored by the addition of Co(2+). Activity measurements together with sequence alignments and structure analysis confirmed that PaYqhD belongs to the butanol dehydrogenase-like enzymes within group III of ADHs.

  7. Metal Reduction and Iron Biomineralization by a Psychrotolerant Fe(III)-Reducing Bacterium, Shewanella sp. Strain PV-4

    SciTech Connect

    Roh, Yul; Gao, Haichun; Vali, Hojatollah; Kennedy, David W.; Yang, Zamin; Gao, Weimin; Dohnalkova, Alice; Stapleton, Raymond D.; Moon, Ji-Won; Phelps, Tommy J.; Fredrickson, Jim K.; Zhou, Jizhong

    2006-09-01

    A marine psychrotolerant, dissimilatory Fe(III)-reducing bacterium, Shewanella sp. strain PV-4, from the microbial mat at a hydrothermal vent of Loihi Seamount in the Pacific Ocean has been further characterized, with emphases on metal reduction and iron biomineralization. The strain is able to reduce metals such as Fe(III), Co(III), Cr(VI), Mn(IV), and U(VI) as electron acceptors while using lactate, formate, pyruvate, or hydrogen as an electron donor. Growth during iron reduction occurred over the pH range of 7.0 to 8.9, a sodium chloride range of 0.05 to 5%, and a temperature range of 0 to 37 C, with an optimum growth temperature of 18 C. Unlike mesophilic dissimilatory Fe(III)-reducing bacteria, which produce mostly superparamagnetic magnetite (<35 nm), this psychrotolerant bacterium produces well-formed single-domain magnetite (>35 nm) at temperatures from 18 to 37 C. The genome size of this strain is about 4.5 Mb. Strain PV-4 is sensitive to a variety of commonly used antibiotics except ampicillin and can acquire exogenous DNA (plasmid pCM157) through conjugation.

  8. Metal Reduction and Iron Biomineralization by a Psychrotolerant Fe(III)-Reducing Bacterium, Shewanella sp. Strain PV-4

    SciTech Connect

    Roh, Yul; Gao, Haichun; Vali, Hojatollah; Kennedy, David W.; Yang, Zamin; Gao, Weimin; Dohnalkova, Alice; Stapleton, Raymond D.; Moon, Ji-Won; Phelps, T. J.; Fredrickson, Jim K.; Zhou, Jizhong

    2006-05-01

    A marine psychrotolerant, dissimilatory Fe(III)-reducing bacterium, Shewanella sp. strain PV-4, from the microbial mat at a hydrothermal vent of Loihi Seamount in the Pacific Ocean has been further characterized, with emphases on metal reduction and iron biomineralization. The strain is able to reduce metals such as Fe(III), Co(III), Cr(VI), Mn(IV), and U(VI) as electron acceptors while using lactate, formate, pyruvate, or hydrogen as an electron donor. Growth during iron reduction occurred over the pH range of 7.0 to 8.9, a sodium chloride range of 0.05 to 5%, and a temperature range of 0 to 37°C, with an optimum growth temperature of 18°C. Unlike mesophilic dissimilatory Fe(III)-reducing bacteria, which produce mostly superparamagnetic magnetite (<35 nm), this psychrotolerant bacterium produces well-formed single-domain magnetite (>35 nm) at temperatures from 18 to 37°C. The genome size of this strain is about 4.5 Mb. Strain PV-4 is sensitive to a variety of commonly used antibiotics except ampicillin and can acquire exogenous DNA (plasmid pCM157) through conjugation.

  9. Variable volume combustor with a conical liner support

    DOEpatents

    Johnson, Thomas Edward; McConnaughhay, Johnie Franklin; Keener, Chrisophter Paul; Ostebee, Heath Michael

    2017-06-27

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a conical liner support supporting the liner.

  10. Fe(III) hydroxide nucleation and growth on quartz in the presence of Cu(II), Pb(II), and Cr(III): metal hydrolysis and adsorption.

    PubMed

    Dai, Chong; Hu, Yandi

    2015-01-06

    Fe(III) hydroxide nanoparticles are an essential carrier for aqueous heavy metals. Particularly, iron hydroxide precipitation on mineral surfaces can immobilize aqueous heavy metals. Here, we used grazing-incidence small-angle X-ray scattering (GISAXS) to quantify nucleation and growth of iron hydroxide on quartz in 0.1 mM Fe(NO3)3 solution in the presence of Na(+), Cu(2+), Pb(2+), or Cr(3+) at pH = 3.7 ± 0.1. In 30 min, the average radii of gyration (R(g)) of particles on quartz grew from around 2 to 6 nm in the presence of Na(+) and Cu(2+). Interestingly, the particle sizes remained 3.3 ± 0.3 nm in the presence of Pb(2+), and few particles formed in the presence of Cr(3+). Quartz crystal microbalance dissipation (QCM-D) measurements showed that only Cr(3+) adsorbed onto quartz, while Cu(2+) and Pb(2+) did not. Cr(3+) adsorption changed the surface charge of quartz from negative to positive, thus inhibiting the precipitation of positively charged iron hydroxide on quartz. Masses and compositions of the precipitates were also quantified. This study provided new insights on interactions among quartz, iron hydroxide, and metal ions. Such information is helpful not only for environmental remediation but also for the doping design of iron oxide catalysts.

  11. Wear versus Thickness and Other Features of 5-Mrad Crosslinked UHMWPE Acetabular Liners

    PubMed Central

    Shen, Fu-Wen; Lu, Zhen

    2010-01-01

    Background The low wear rates of crosslinked polyethylenes provide the potential to use larger diameters to resist dislocation. However, this requires the use of thinner liners in the acetabular component, with concern that higher contact stresses will increase wear, offsetting the benefits of the crosslinking. Questions/purposes We asked the following questions: Is the wear of conventional and crosslinked polyethylene liners affected by ball diameter, rigidity of backing, and liner thickness? Are the stresses in the liner affected by thickness? Methods Wear rates were measured in a hip simulator and stresses were calculated using finite element modeling. Results Without crosslinking, the wear rate was 4% to 10% greater with a 36-mm diameter than a 28-mm diameter. With crosslinking, wear was 9% lower with a 36-mm diameter without metal backing and 4% greater with metal backing. Reducing the thickness from 6 mm to 3 mm increased the contact stress by 46%, but the wear rate decreased by 19%. Conclusions The reduction in wear with 5 Mrad of crosslinking was not offset by increasing the diameter from 28 mm to 36 mm or by using a liner as thin as 3 mm. Clinical Relevance The results indicate, for a properly positioned 5-Mrad crosslinked acetabular component and within the range of dimensions evaluated, neither wear nor stresses in the polyethylene are limiting factors in the use of larger-diameter, thinner cups to resist dislocation. PMID:20848244

  12. VPS GRCop-84 Liner Development Efforts

    NASA Technical Reports Server (NTRS)

    Elam, Sandra K.; Holmes, Richard; McKechnie, Tim; Hickman, Robert; Pickens, Tim

    2003-01-01

    For the past several years, NASA's Marshall Space Flight Center (MSFC) has been working with Plasma Processes, Inc. (PPI) to fabricate combustion chamber liners using the Vacuum Plasma Spray (VPS) process. Multiple liners of a variety of shapes and sizes have been created. Each liner has been fabricated with GRCop-84 (a copper alloy with chromium and niobium) and a functional gradient coating (FGC) on the hot wall. While the VPS process offers versatility and a reduced fabrication schedule, the material system created with VPS allows the liners to operate at higher temperatures, with maximum blanch resistance and improved cycle life. A subscal unit (5K lbf thrust class) is being cycle tested in a LOX/Hydrogen thrust chamber assembly at MSFC. To date, over 75 hot-fire tests have been accumulated on this article. Tests include conditions normally detrimental to conventional materials, yet the VPS GRCop-84 liner has yet to show any signs of degradation. A larger chamber (15K lbf thrust class) has also been fabricated and is being prepared for hot-fire testing at MSFC near the end of 2003. Linear liners have been successfully created to further demonstrate the versatility of the process. Finally, scale up issues for the VPS process are being tackled with efforts to fabricate a full size, engine class liner. Specifically, a liner for the SSME's Main Combustion Chamber (MCC) has recently been attempted. The SSME size was chosen for convenience, since its design was readily available and its size was sufficient to tackle specific issues. Efforts to fabricate these large liners have already provided valuable lessons for using this process for engine programs. The material quality for these large units is being evaluated with destructive analysis and these results will be available by the end of 2003.

  13. Ultraviolet spectrophotometry of three LINERs

    NASA Technical Reports Server (NTRS)

    Goodrich, R. W.; Keel, W. C.

    1986-01-01

    Three galaxies known to be LINERs were observed spectroscopically in the ultraviolet in an attempt to detect the presumed nonthermal continuum source thought to be the source of photoionization in the nuclei. NGC 4501 was found to be too faint for study with the IUE spectrographs, while NGC 5005 had an extended ultraviolet light profile. Comparison with the optical light profile of NGC 5005 indicates that the ultraviolet source is distributed spatially in the same manner as the optical starlight, probably indicating that the ultraviolet excess is due to a component of hot stars in the nucleus. These stars contribute detectable absorption features longward of 2500 A; together with optical data, the IUE spectra suggest a burst of star formation about 1 billion yr ago, with a lower rate continuing to produce a few OB stars. In NGC 4579, a point source contributing most of the ultraviolet excess is found that is much different than the optical light distribution. Furthermore, the ultraviolet to X-ray spectral index in NGC 4579 is 1.4, compatible with the UV to X-ray indices found for samples of Seyfert galaxies. This provides compelling evidence for the detection of the photoionizing continuum in NGC 4579 and draws the research fields of normal galaxies and active galactic nuclei closer together. The emission-line spectrum of NGC 4579 is compared with calculations from a photoionization code, CLOUDY, and several shock models. The photoionization code is found to give superior results, adding to the increasing weight of evidence that the LINER phenomenon is essentially a scaled-down version of the Seyfert phenomenon.

  14. Halogen-bonding in a new family of tris(haloanilato)metallate(III) magnetic molecular building blocks.

    PubMed

    Atzori, Matteo; Artizzu, Flavia; Sessini, Elisa; Marchiò, Luciano; Loche, Danilo; Serpe, Angela; Deplano, Paola; Concas, Giorgio; Pop, Flavia; Avarvari, Narcis; Mercuri, Maria Laura

    2014-05-21

    Here we report on new tris(haloanilato)metallate(III) complexes with general formula [A]3[M(X2An)3] (A = (n-Bu)4N(+), (Ph)4P(+); M = Cr(III), Fe(III); X2An = 3,6-dihalo derivatives of 2,5-dihydroxybenzoquinone (H4C6O4), chloranilate (Cl2An(2-)), bromanilate (Br2An(2-)) and iodanilate (I2An(2-))), obtained by a general synthetic strategy, and their full characterization. The crystal structures of these Fe(III) and Cr(III) haloanilate complexes consist of anions formed by homoleptic complexes formulated as [M(X2An)3](3-) and (Et)3NH(+), (n-Bu)4N(+), or (Ph4)P(+) cations. All complexes exhibit octahedral coordination geometry with metal ions surrounded by six oxygen atoms from three chelate ligands. These complexes are chiral according to the metal coordination of three bidentate ligands, and both Λ and Δ enantiomers are present in their crystal lattice. The packing of [(n-Bu)4N]3[Cr(I2An)3] (5a) shows that the complexes form supramolecular dimers that are held together by two symmetry related I···O interactions (3.092(8) Å), considerably shorter than the sum of iodine and oxygen van der Waals radii (3.50 Å). The I···O interaction can be regarded as a halogen bond (XB), where the iodine behaves as the XB donor and the oxygen atom as the XB acceptor. This is in agreement with the properties of the electrostatic potential for [Cr(I2An)3](3-) that predicts a negative charge accumulation on the peripheral oxygen atoms and a positive charge accumulation on the iodine. The magnetic behaviour of all complexes, except 5a, may be explained by considering a set of paramagnetic non-interacting Fe(III) or Cr(III) ions, taking into account the zero-field splitting effect. The presence of strong XB interactions in 5a are able, instead, to promote antiferromagnetic interactions among paramagnetic centers at low temperature, as shown by the fit with the Curie-Weiss law, in agreement with the formation of halogen-bonded supramolecular dimers.

  15. Beryllium liner implosion experiments on the Z accelerator in preparation for magnetized liner inertial fusion

    SciTech Connect

    McBride, R. D.; Martin, M. R.; Lemke, R. W.; Jennings, C. A.; Rovang, D. C.; Sinars, D. B.; Cuneo, M. E.; Herrmann, M. C.; Slutz, S. A.; Nakhleh, C. W.; Davis, J.-P.; Flicker, D. G.; Rogers, T. J.; Robertson, G. K.; Kamm, R. J.; Smith, I. C.; Savage, M.; Stygar, W. A.; Rochau, G. A.; Jones, M.; and others

    2013-05-15

    Multiple experimental campaigns have been executed to study the implosions of initially solid beryllium (Be) liners (tubes) on the Z pulsed-power accelerator. The implosions were driven by current pulses that rose from 0 to 20 MA in either 100 or 200 ns (200 ns for pulse shaping experiments). These studies were conducted in support of the recently proposed Magnetized Liner Inertial Fusion concept [Slutz et al., Phys. Plasmas 17, 056303 (2010)], as well as for exploring novel equation-of-state measurement techniques. The experiments used thick-walled liners that had an aspect ratio (initial outer radius divided by initial wall thickness) of either 3.2, 4, or 6. From these studies, we present three new primary results. First, we present radiographic images of imploding Be liners, where each liner contained a thin aluminum sleeve for enhancing the contrast and visibility of the liner's inner surface in the images. These images allow us to assess the stability of the liner's inner surface more accurately and more directly than was previously possible. Second, we present radiographic images taken early in the implosion (prior to any motion of the liner's inner surface) of a shockwave propagating radially inward through the liner wall. Radial mass density profiles from these shock compression experiments are contrasted with profiles from experiments where the Z accelerator's pulse shaping capabilities were used to achieve shockless (“quasi-isentropic”) liner compression. Third, we present “micro-B-dot ” measurements of azimuthal magnetic field penetration into the initially vacuum-filled interior of a shocked liner. Our measurements and simulations reveal that the penetration commences shortly after the shockwave breaks out from the liner's inner surface. The field then accelerates this low-density “precursor” plasma to the axis of symmetry.

  16. How to prevent deep-well liner failure

    SciTech Connect

    Durham, K.S.

    1987-11-01

    This article discusses three liner design rules to prevent deep-well liner failure. They are: 1) Always select heavier weight casing, all other things being equal. 2) Always suspect that liner tops and casing shoes will leak. Design accordingly. 3) Liner tension designs should always include ballooning and temperature effects of stimulation. The article also gives some guidelines that will lead to better deep-well liner designs and reduce mechanical risk, according to the author.

  17. PopIII-star siblings in IZw18 and metal-poor WR galaxies unveiled from integral field spectroscopy

    NASA Astrophysics Data System (ADS)

    Kehrig, C.; Vílchez, J. M.; Pérez-Montero, E.; Iglesias-Páramo, J.; Brinchmann, J.; Crowther, P. A.; Durret, F.; Kunth, D.

    Here, we highlight our recent results from the IFS study of Mrk178, the closest metal-poor WR galaxy, and of IZw18, the most metal-poor star-forming galaxy known in the local Universe. The IFS data of Mrk178 show the importance of aperture effects on the search for WR features, and the extent to which physical variations in the ISM properties can be detected. Our IFS data of IZw18 reveal its entire nebular HeIIλ4686-emitting region, and indicate for the very first time that peculiar, hot (nearly) metal-free ionizing stars (called here PopIII-star siblings) might hold the key to the HeII-ionization in IZw18.

  18. Backside nonconformity and locking restraints affect liner/shell load transfer mechanisms and relative motion in modular acetabular components for total hip replacement.

    PubMed

    Kurtz, S M; Ochoa, J A; White, C V; Srivastav, S; Cournoyer, J

    1998-05-01

    Nonconformity between the polyethylene liner and the metal shell may exist in modular acetabular components by design, due to manufacturing tolerances, or from locking mechanisms that attach the polyethylene liner to the metal shell. Relative motion at the liner/shell interface has been associated with backside wear, which may contribute to osteolysis which has been clinically observed near screw holes. The purpose of this study was to investigate the effect of nonconformity and locking restraints on the liner/shell relative motion and load transfer mechanisms in a commercially available, metal-backed acetabular component with a polar fenestration. The finite element method was used to explore the hypothesis that backside nonconformity and locking restraints play important roles in long-term surface damage mechanisms that are unique to modular components, such as backside wear and liner extrusion through screw holes. The three-body quasi-static contact problem was solved using a commercially available explicit finite element code, which modeled contact between the femoral head, polyethylene liner, and the metal shell. Four sets of liner boundary conditions were investigated: no restraints, rim restraints, equatorial restraints, and both rim and equatorial restraints. The finite element model with a conforming shell predicted between 8.5 and 12.8 microm of incremental extrusion of the polyethylene through the polar fenestration, consistent with in vitro experiments of the same design under identical loading conditions. Furthermore, idealized rim and/or equatorial liner restraints were found to share up to 71% of the load across the liner/shell interface. Consequently, the results of this study demonstrate that backside nonconformity and locking restraints substantially influence backside relative motion as well as load transfer at the liner/shell interface.

  19. Half-metallicity and electronic structures for carbon-doped group III-nitrides: Calculated with a modified Becke-Johnson potential

    NASA Astrophysics Data System (ADS)

    Fan, Shuai-wei; Wang, Ri-gao; Xu, Pemg

    2016-09-01

    The electronic structures and magnetism for carbon-doped group III-nitrides are investigated by utilizing the first principle method with the modified Becke-Johnson potential. Calculations show that carbon substituting cations (anions) would induce the group III-nitrides to be paramagnetic metals (half-metallic ferromagnets). Single carbon substituting nitrogen could produce 1.00μB magnetic moment. Electronic structures indicate that the carriers-mediated double-exchange interaction plays a crucial role in forming the ferromagnetism. Based on the mean-field theory, the Curie temperature for carbon-doped group III-nitrides would be above the room temperature. Negative chemical pair interactions imply that carbon dopants tend to form clustering distribution in group III-nitrides. The nitrogen vacancy would make the carbon-doped group III-nitrides lose the half-metallic ferromagnetism.

  20. A synthetic route to ultralight hierarchically micro/mesoporous Al(III)-carboxylate metal-organic aerogels

    PubMed Central

    Li, Lei; Xiang, Shenglin; Cao, Shuqi; Zhang, Jianyong; Ouyang, Gangfeng; Chen, Liuping; Su, Cheng-Yong

    2013-01-01

    Developing a synthetic methodology for the fabrication of hierarchically porous metal-organic monoliths that feature high surface area, low density and tunable porosity is imperative for mass transfer applications, including bulky molecule capture, heterogeneous catalysis and drug delivery. Here we report a versatile and facile synthetic route towards ultralight micro/mesoporous metal-organic aerogels based on the two-step gelation of metal-organic framework nanoparticles. Heating represents a key factor in the control of gelation versus crystallization of Al(III)-multicarboxylate systems. The porosity of the resulting metal-organic aerogels can be readily tuned, leading to the formation of well-ordered intraparticle micropores and aerogel-specific interparticle mesopores, thereby integrating the merits of both crystalline metal-organic frameworks and light aerogels. The hierarchical micro/mesoporosity of the Al-metal-organic aerogels is thoroughly evaluated by N2 sorption. The good accessibility of the micro/mesopores is verified by vapour/dye uptake, and their potential for utilization as effective fibre-coating absorbents is tested in solid-phase microextraction analyses. PMID:23653186

  1. Time Dependent Effect of a Denture Cleanser on the Sorption and Solubility of Four Soft Liners-An Invitro Study

    PubMed Central

    Sudhapalli, Sruthikeerthi

    2016-01-01

    Introduction Soft liner materials, when used with ill fitting dentures, are constantly kept in a wet environment of either saliva or denture cleanser that affects their sorption and solubility. These inturn have detrimental effect on other properties. Aim To evaluate the influence of different exposure times of a commonly used denture cleanser on sorption and solubility of four soft liners. Materials and Methods Metal disc was fabricated to make the mould space for soft liner samples. Four materials were used, long term and short term acrylic liners; long term and short term silicone liners. Each of these were divided into four groups: first control group– all liners were kept in artificial saliva for entire period of study. Second group- liners were immersed daily in cleanser for 1 hour and then transferred to artificial saliva for rest of the day. Similarly samples of third and fourth groups were immersed in cleanser for 4 and 8 hours respectively and transferred to artificial saliva. Sorption and solubility tests were conducted and statistical analysis done. Statistical Analysis One-way ANOVA followed by Post-hoc Tukey’s test for pair wise comparisons was done. Significance was set at the probability level of p < 0.05. Results Solubility values of all groups were higher than the quoted ADA specifications. Conclusion Overall, silicones performed better than acrylics. Long term silicone was most stable. Short term acrylic was most unstable. The 8 hour immersion in denture cleanser caused significantly high sorption and solubility. PMID:27190940

  2. Use of coal mining waste for the removal of acidity and metal ions Al (III), Fe (III) and Mn (II) in acid mine drainage.

    PubMed

    Geremias, R; Laus, R; Macan, J M; Pedrosa, R C; Laranjeira, M C M; Silvano, J; Fávere, F V

    2008-08-01

    The coal industry may generate acid mine drainage (AMD) and mining wastes, which may adversely affect the quality of the environment. In this study we propose the use of this waste in the removal of acidity and metal ions, as well as in the reduction of the toxicity of AMD. A physico-chemical analysis of the waste shows the presence of mainly SiO2, Al2O3 and Fe2O3 and a superficial area of 4.316 m2 g(-1). The treatment of AMD with the waste resulted in an increase in pH from 2.6 to 7.8 and removed 100% of the Al (III), 100% of the Fe (III) and 89% of the Mn (II). We also observed that the high toxicity of the AMD towards Daphnia magna (LC50 = 3.68%) and Artemia sp. (LC50 = 4.97%) was completely eliminated after treatment with the waste. The data obtained allow us to propose that the waste can be used in the treatment of AMD, providing an economic use for the waste.

  3. Drapery assembly including insulated drapery liner

    DOEpatents

    Cukierski, Gwendolyn

    1983-01-01

    A drapery assembly is disclosed for covering a framed wall opening, the assembly including drapery panels hung on a horizontal traverse rod, the rod having a pair of master slides and means for displacing the master slides between open and closed positions. A pair of insulating liner panels are positioned behind the drapery, the remote side edges of the liner panels being connected with the side portions of the opening frame, and the adjacent side edges of the liner panels being connected with a pair of vertically arranged center support members adapted for sliding movement longitudinally of a horizontal track member secured to the upper horizontal portion of the opening frame. Pivotally arranged brackets connect the center support members with the master slides of the traverse rod whereby movement of the master slides to effect opening and closing of the drapery panels effects simultaneous opening and closing of the liner panels.

  4. HEL-1: A DEMG Based Demonstration of Solid Liner Implosions at 100 MA

    SciTech Connect

    Reinovsky, R.E.; Anderson, B.G.; Clark, D.A.

    1997-12-31

    In August 1997, the Los Alamos National Laboratory (LANL) and the All-Russian Scientific Research Institute of Experimental Physics (VNIIEF) conducted a joint experiment in Sarov, Russia to demonstrate the feasibility of applying explosive pulsed power technology to implode large scale, high velocity cylindrical liners. Kilogram mass metal liners imploding at velocities of 5-25 km/sec are useful scientific tools for producing high energy density environments, ultra high pressure shocks, and for the rapid compression of plasmas. To explore the issues associated with the design, operation and diagnosis of such implosions, VNIIEF and LANL designed and executed an practical demonstration in which a liner of approximately 1 kilogram mass was accelerated to 510 km/sec while undergoing a convergence of about 4:1. The scientific objectives of the experiment were threefold. First to explore the limits of very large, explosive, pulse power system delivering about 100 MA as drivers for accelerating solid density imploding liners to kinetic energies of 25 MJ or greater. Second to evaluate the behavior of single material (aluminum) liners imploding at 510 km/sec velocities by comparing experimental data with 1-D and 2-D numerical simulations. Third, to evaluate the condition of the selected liner at radial convergence of 4 and a final radius of 6 cm. A liner of such parameters could be used as a driver for equation of state measurements at megabar pressures or as a driver for a future experiment in which a magnetized fusion plasma would be compressed to approach ignition conditions.

  5. Prospects for x-ray polarimetry measurements of magnetic fields in magnetized liner inertial fusion plasmas

    SciTech Connect

    Lynn, Alan G. Gilmore, Mark

    2014-11-15

    Magnetized Liner Inertial Fusion (MagLIF) experiments, where a metal liner is imploded to compress a magnetized seed plasma may generate peak magnetic fields ∼10{sup 4} T (100 Megagauss) over small volumes (∼10{sup −10}m{sup 3}) at high plasma densities (∼10{sup 28}m{sup −3}) on 100 ns time scales. Such conditions are extremely challenging to diagnose. We discuss the possibility of, and issues involved in, using polarimetry techniques at x-ray wavelengths to measure magnetic fields under these extreme conditions.

  6. Prospects for x-ray polarimetry measurements of magnetic fields in magnetized liner inertial fusion plasmas.

    PubMed

    Lynn, Alan G; Gilmore, Mark

    2014-11-01

    Magnetized Liner Inertial Fusion (MagLIF) experiments, where a metal liner is imploded to compress a magnetized seed plasma may generate peak magnetic fields ∼10(4) T (100 Megagauss) over small volumes (∼10(-10)m(3)) at high plasma densities (∼10(28)m(-3)) on 100 ns time scales. Such conditions are extremely challenging to diagnose. We discuss the possibility of, and issues involved in, using polarimetry techniques at x-ray wavelengths to measure magnetic fields under these extreme conditions.

  7. Elucidation of metal-ion accumulation induced by hydrogen bonds on protein surfaces by using porous lysozyme crystals containing Rh(III) ions as the model surfaces.

    PubMed

    Ueno, Takafumi; Abe, Satoshi; Koshiyama, Tomomi; Ohki, Takahiro; Hikage, Tatsuo; Watanabe, Yoshihito

    2010-03-01

    Metal-ion accumulation on protein surfaces is a crucial step in the initiation of small-metal clusters and the formation of inorganic materials in nature. This event is expected to control the nucleation, growth, and position of the materials. There remain many unknowns, as to how proteins affect the initial process at the atomic level, although multistep assembly processes of the materials formation by both native and model systems have been clarified at the macroscopic level. Herein the cooperative effects of amino acids and hydrogen bonds promoting metal accumulation reactions are clarified by using porous hen egg white lysozyme (HEWL) crystals containing Rh(III) ions, as model protein surfaces for the reactions. The experimental results reveal noteworthy implications for initiation of metal accumulation, which involve highly cooperative dynamics of amino acids and hydrogen bonds: i) Disruption of hydrogen bonds can induce conformational changes of amino-acid residues to capture Rh(III) ions. ii) Water molecules pre-organized by hydrogen bonds can stabilize Rh(III) coordination as aqua ligands. iii) Water molecules participating in hydrogen bonds with amino-acid residues can be replaced by Rh(III) ions to form polynuclear structures with the residues. iv) Rh(III) aqua complexes are retained on amino-acid residues through stabilizing hydrogen bonds even at low pH (approximately 2). These metal-protein interactions including hydrogen bonds may promote native metal accumulation reactions and also may be useful in the preparation of new inorganic materials that incorporate proteins.

  8. Liner target interaction experiments on Pegasus II

    SciTech Connect

    Hockaday, M.P.; Chrien, R.E.; Bartsch, R.

    1995-09-01

    The Los Alamos High Energy Density Physics program uses capacitively driven low voltage, inductive-storage pulse power to implode cylindrical targets for hydrodynamics experiments. Once a precision driver liner was characterized an experimental series characterizing the aluminum target dynamics was performed. The target was developed for shock-induced quasi-particle ejecta experiments including holography. The concept for the Liner shock experiment is that the driver liner is used to impact the target liner which then accelerates toward a collimator with a slit in it. A shock wave is set up in the target liner and as the shock emerges from the back side of the target liner, ejecta are generated. By taking a laser hologram the particle distribution of the ejecta are hoped to be determined. The goal for the second experimental series was to characterize the target dynamics and not to measure and generate the ejecta. Only the results from the third shot, Pegasus II-26 fired April 26th, 1994, from the series is discussed in detail. The second experimental series successfully characterized the target dynamics necessary to move forward towards the planned quasi-ejecta experiments.

  9. Thin Foil Copper Liner Initiation Experiments

    NASA Astrophysics Data System (ADS)

    Blesener, Isaac; Kusse, Bruce; Greenly, John; Blesener, Kate; Hammer, David; Blue, Brent

    2011-10-01

    Solid liners are an increasingly attractive load design for pulsed power drivers, with applications in both Z pinches and alternative fusion concepts. Next generation pulsed power drivers will need increasingly massive loads to match the implosion time of the Z pinch with the current pulse. Solid liners present a relatively simple load design that could replace wire arrays for fast Z pinch studies. Additionally, fusion concepts such as MAGnetized Liner Intertial Fusion (MAGLIF) are designed to use solid liners to compress the fusion fuel. One problem that has hindered the performance of solid liners in the past is non-uniform initiation, or current filamentation. A series of experiments on the 1 MA, 100 ns COBRA generator show that at high enough current density rise times (dJ/dt), copper liners initiated nearly instaneously and uniformly along the azimuth. The threshold for these experiments for uniform initiation was found to be dJ/dt >= 3 . 5 ×1016A/cm2 s . This research is supported by the NNSA SSAA program under DOE Cooperative Agreement DE-FC03-02NA00057.

  10. CANMET Gasifier Liner Coupon Material Test Report

    SciTech Connect

    Mark Fitzsimmons; Dave Grimmett; Bryan McEnerney

    2007-01-31

    This report provides detailed test results consisting of test data and post-test inspections from Task 1 ''Cooled Liner Coupon Development and Test'' of the project titled ''Development of Technologies and Capabilities for Coal Energy Resources--Advanced Gasification Systems Development (AGSD)''. The primary objective of this development and test program is to verify that ceramic matrix composite (CMC) liner materials planned for use in an advanced gasifier pilot plant will successfully withstand the environments in a commercial gasifier. Pratt & Whitney Rocketdyne (PWR) designed and fabricated the cooled liner test assembly article that was tested in a slagging gasifier at CANMET Energy Technology Center (CETC-O) in Ottawa, Ontario, Canada. The test program conducted in 2006 met the objective of operating the cooled liner test article at slagging conditions in a small scale coal gasifier at CETC-O for over the planned 100 hours. The test hardware was exposed to at least 30 high temperature excursions (including start-up and shut-down cycles) during the test program. The results of the testing has provided valuable information on gasifier startup and required cooling controls in steady state operation of future advanced gasifiers using similar liners. The test program also provided a significant amount of information in the areas of CMC materials and processing for improved capability in a gasifier environment and insight into CMC liner fabrication that will be essential for near-term advanced gasifier projects.

  11. Fe(III)-based metal-organic framework-derived core-shell nanostructure: Sensitive electrochemical platform for high trace determination of heavy metal ions.

    PubMed

    Zhang, Zhihong; Ji, Hongfei; Song, Yingpan; Zhang, Shuai; Wang, Minghua; Jia, Changchang; Tian, Jia-Yue; He, Linghao; Zhang, Xiaojing; Liu, Chun-Sen

    2017-03-07

    A new core-shell nanostructured composite composed of Fe(III)-based metal-organic framework (Fe-MOF) and mesoporous Fe3O4@C nanocapsules (denoted as Fe-MOF@mFe3O4@mC) was synthesized and developed as a platform for determining trace heavy metal ions in aqueous solution. Herein, the mFe3O4@mC nanocapsules were prepared by calcining the hollow Fe3O4@C that was obtained using the SiO2 nanoparticles as the template, followed by composing the Fe-MOF. The Fe-MOF@mFe3O4@mC nanocomposite demonstrated excellent electrochemical activity, water stability and high specific surface area, consequently resulting in the strong biobinding with heavy-metal-ion-targeted aptamer strands. Furthermore, by combining the conformational transition interaction, which is caused by the formation of the G-quadruplex between a single-stranded aptamer and high adsorbed amounts of heavy metal ions, the developed aptasensor exhibited a good linear relationship with the logarithm of heavy metal ion (Pb(2+) and As(3+)) concentration over the broad range from 0.01 to 10.0nM. The detection limits were estimated to be 2.27 and 6.73 pM toward detecting Pb(2+) and As(3+), respectively. The proposed aptasensor showed good regenerability, excellent selectivity, and acceptable reproducibility, suggesting promising applications in environment monitoring and biomedical fields.

  12. Is there material loss at the backside taper in modular CoCr acetabular liners?

    PubMed

    Agne, Matthias T; Underwood, Richard J; Kocagoz, Sevi B; MacDonald, Daniel W; Day, Judd S; Parvizi, Javad; Kraay, Matthew J; Mont, Michael A; Klein, Gregg R; Cates, Harold E; Kurtz, Steven M

    2015-01-01

    Metal wear and corrosion products generated by hip replacements have been linked to adverse local tissue reactions. Recent investigations of the stem/head taper junction have identified this modular interface as another possible source of metal debris; however, little is known regarding other modular metallic interfaces, their ability to produce metal debris, and possibly to provide insight in the mechanisms that produce metal debris. We asked three questions: (1) can we develop a reliable method to estimate volumetric material loss from the backside taper of modular metal-on-metal liners, (2) do backside tapers of modular metal-on-metal liners show a quantifiable volumetric material loss, and, if so, (3) how do regions of quantitatively identified material loss correspond to visual and microscopic investigations of surface damage? Twenty-one cobalt-chromium (CoCr) liners of one design and manufacturer were collected through an institutional review board-approved retrieval program. All liners were collected during revision surgeries, where the primary revision reason was loosening (n=11). A roundness machine measured 144 axial profiles equally spaced about the circumference of the taper region near the rim to estimate volume and depth of material loss. Sensitivity and repeatability analyses were performed. Additionally, visual and scanning electron microscopy investigations were done for three liners. Our measurement method was found to be reproducible. The sensitivity (how dependent measurement results are on experimental parameters) and repeatability (how consistent results are between measurements) analyses confirmed that component alignment had no apparent effect (weak correlation, R2=0.04) on estimated volumetric material loss calculations. Liners were shown to have a quantifiable material loss (maximum=1.7 mm3). Visual investigations of the liner surface could identify pristine surfaces as as-manufactured regions, but could misidentify discoloration as a

  13. Tokamak with liquid metal toroidal field coil

    DOEpatents

    Ohkawa, Tihiro; Schaffer, Michael J.

    1981-01-01

    Tokamak apparatus includes a pressure vessel for defining a reservoir and confining liquid therein. A toroidal liner disposed within the pressure vessel defines a toroidal space within the liner. Liquid metal fills the reservoir outside said liner. Electric current is passed through the liquid metal over a conductive path linking the toroidal space to produce a toroidal magnetic field within the toroidal space about the major axis thereof. Toroidal plasma is developed within the toroidal space about the major axis thereof.

  14. DFT modeling and spectroscopic study of metal ligand bonding in La(III) complex of coumarin-3-carboxylic acid

    NASA Astrophysics Data System (ADS)

    Mihaylov, Tz.; Trendafilova, N.; Kostova, I.; Georgieva, I.; Bauer, G.

    2006-09-01

    The binding mode of coumarin-3-carboxylic acid (HCCA) to La(III) is elucidated at experimental and theoretical level. The complexation ability of the deprotonated ligand (CCA -) to La(III) is studied using elemental analysis, DTA and TGA data as well as FTIR, 1H NMR and 13C NMR spectra. The experimental data suggest the complex formula La(CCA) 2(NO 3)(H 2O) 2. B3LYP, BHLYP, B3P86, B3PW91, PW91P86 and MPW1PW91 functionals are tested for geometry and frequency calculations of the neutral ligand and all of them show bond length deviations bellow 1%. B3LYP/6-31G(d) level combined with large quasi-relativistic effective core potential for lanthanum is selected to describe the molecular, electronic and vibrational structures as well as the conformational behavior of HCCA, CCA - and La-CCA complex. The metal-ligand binding mode is predicted through molecular modeling and energy estimation of different La-CCA structures. The calculated atomic charges and the bonding orbital polarizations point to strong ionic metal-ligand bonding in La-CCA complex and insignificant donor acceptor interaction. Detailed vibrational analysis of HCCA, CCA - and La(CCA) 2(NO 3)(H 2O) 2 systems based on both calculated and experimental frequencies confirms the suggested metal-ligand binding mode.

  15. Combined mode I-mode III fracture toughness of a particulate reinforced metal-matrix composite

    NASA Technical Reports Server (NTRS)

    Manoharan, M.; Lewandowski, J. J.

    1991-01-01

    The aim of this investigation was to determine the fracture behavior of a particulate reinfored aluminum alloy composite under combined mode I-mode III loading conditions. A modified three-point bend specimen was used to carry out these tests. It was found that the mode I loading condition was energetically most favorable. Addition of mode III components to the system seems to increase the amount of redundant work during fracture without affecting the critical fracture criterion.

  16. Combined mode I-mode III fracture toughness of a particulate reinforced metal-matrix composite

    NASA Technical Reports Server (NTRS)

    Manoharan, M.; Lewandowski, J. J.

    1991-01-01

    The aim of this investigation was to determine the fracture behavior of a particulate reinfored aluminum alloy composite under combined mode I-mode III loading conditions. A modified three-point bend specimen was used to carry out these tests. It was found that the mode I loading condition was energetically most favorable. Addition of mode III components to the system seems to increase the amount of redundant work during fracture without affecting the critical fracture criterion.

  17. Development of a fracture control method for composite tanks with load sharing liners

    NASA Technical Reports Server (NTRS)

    Bixler, W. D.

    1973-01-01

    This experimental program was undertaken to establish a fracture control method for composite tanks with load sharing liners. Uniaxial specimens containing surface flaws were loaded to failure (static fractured) and cycled to failure and the results were compared with burst tests and cyclic life tests of composite tanks having surface flaws present in the load sharing metal liners. The liner materials investigated were Inconel X750 STA, 2219-T62 aluminum and cryostretched 301 stainless steel at room temperature and at 78 K (-320 F) in liquid nitrogen. Differences were observed in comparing the uniaxial and tank test results. These differences should be resolved if an adequate fracture control method is to be developed.

  18. Synthesis, structural characterization, luminescent properties and theoretical study of three novel lanthanide metal-organic frameworks of Ho(III), Gd(III) and Eu(III) with 2,5-thiophenedicarboxylate anion

    SciTech Connect

    Marques, Lippy F.; Correa, Charlane C.; Ribeiro, Sidney J.L.; Santos, Molíria V. dos; Dutra, José Diogo L.; Freire, Ricardo O.; Machado, Flávia C.

    2015-07-15

    In this paper, the synthesis of three new metal-organic frameworks of lanthanides (LnMOFs) ([Ln{sub 2}(2,5-tdc){sub 3}(dmso){sub 2}]·H{sub 2}O){sub n} (Ln=Ho (1); Gd (2); Eu (3); 2,5-tdc=2,5-thiophenedicarboxylate anion; dmso=dimethylsulfoxide), and their complete characterization, including single crystal X-ray diffraction, FTIR spectroscopy and thermogravimetric analysis are reported. In especial, photophysical properties of Eu(III) complex have been studied in detail via both theoretical and experimental approaches. Crystal structure of (1) reveals that each lanthanide ion is seven-coordinated by oxygen atoms in an overall distorted capped trigonal – prismatic geometry. The 2,5-tdc{sup 2−} ligands connect four Ln(III) centers, adopting (κ{sup 1}–κ{sup 1})–(κ{sup 1}–κ{sup 1})–μ{sub 4} coordination mode, generating an 8-connected uninodal 3D network. In addition, theoretical studies for Eu(III) complex were performed using the Sparkle model for lanthanide complexes. - Graphical abstract: Three new metal-organic frameworks of lanthanides (LnMOFs) ([Ln{sub 2}(2,5-tdc){sub 3}(dmso){sub 2}]·H{sub 2}O){sub n} (Ln=Ho (1); Gd (2); Eu (3); 2,5-tdc=2,5-thiophenedicarboxylate anion; dmso=dimethylsulfoxide), were synthesized and their complete characterization, including single crystal X-ray diffraction, FTIR spectroscopy and thermogravimetric analysis are reported. In especial, photophysical properties of Eu(III) complex have been studied in detail via both theoretical and experimental approaches. - Highlights: • Three new LnMOFs were synthesized and fully characterized. • Ho{sup 3+}, Gd{sup 3+} and Eu{sup 3+} complexes photoluminescence properties were investigated. • Theoretical approaches for Eu{sup 3+} complex luminescence has been performed. • An energy level diagram is used to establish the ligand-to-metal energy transfer. • These metal−organic frameworks can act as light conversion molecular devices.

  19. Galvanic reduction of uranium(III) chloride from LiCl-KCl eutectic salt using gadolinium metal

    NASA Astrophysics Data System (ADS)

    Bagri, Prashant; Zhang, Chao; Simpson, Michael F.

    2017-09-01

    The drawdown of actinides is an important unit operation to enable the recycling of electrorefiner salt and minimization of waste. A new method for the drawdown of actinide chlorides from LiCl-KCl molten salt has been demonstrated here. Using the galvanic interaction between the Gd/Gd(III) and U/U(III) redox reactions, it is shown that UCl3 concentration in eutectic LiCl-KCl can be reduced from 8.06 wt.% (1.39 mol %) to 0.72 wt.% (0.12 mol %) in about an hour via plating U metal onto a steel basket. This is a simple process for returning actinides to the electrorefiner and minimizing their loss to the salt waste stream.

  20. Accumulation capacitance frequency dispersion of III-V metal-insulator-semiconductor devices due to disorder induced gap states

    SciTech Connect

    Galatage, R. V.; Zhernokletov, D. M.; Dong, H.; Brennan, B.; Hinkle, C. L.; Wallace, R. M.; Vogel, E. M.

    2014-07-07

    The origin of the anomalous frequency dispersion in accumulation capacitance of metal-insulator-semiconductor devices on InGaAs and InP substrates is investigated using modeling, electrical characterization, and chemical characterization. A comparison of the border trap model and the disorder induced gap state model for frequency dispersion is performed. The fitting of both models to experimental data indicate that the defects responsible for the measured dispersion are within approximately 0.8 nm of the surface of the crystalline semiconductor. The correlation between the spectroscopically detected bonding states at the dielectric/III-V interface, the interfacial defect density determined using capacitance-voltage, and modeled capacitance-voltage response strongly suggests that these defects are associated with the disruption of the III-V atomic bonding and not border traps associated with bonding defects within the high-k dielectric.

  1. Validation of structural analysis methods using burner liner cyclic rig test data

    NASA Technical Reports Server (NTRS)

    Thompson, R.

    1983-01-01

    The objectives of the hot section technology (HOST) burner liner cyclic rig test program are basically threefold: (1) to assist in developing predictive tools needed to improve design analyses and procedures for the efficient and accurate prediction of burner liner structural response; (2) to calibrate, evaluate and validate these predictive tools by comparing the predicted results with the experimental data generated in the tests; and (3) to evaluate existing as well as advanced temperature and strain measurement instrumentation, both contact and noncontact, in a simulated engine cycle environment. The data generated will include measurements of the thermal environment (metal surface temperatures) as well as structural (strain) and life (fatigue) responses of simulated burner liners and specimens under controlled boundary and operating conditions. These data will be used to calibrate, compare and validate analytical theories, methodologies and design procedures, as well as improvements in them, for predicting liner temperatures, stress-strain responses and cycles to failure. Comparison of predicted results with experimental data will be used to show where the predictive theories, etc. need improvements. In addition, as the predictive tools, as well as the tests, test methods, and data acquisition and reduction techniques, are developed and validated, a proven, integrated analysis/experiment method will be developed to determine the cyclic life of a simulated burner liner.

  2. Liner-less Tanks for Space Application - Design and Manufacturing Considerations

    NASA Technical Reports Server (NTRS)

    Jones, Brian H.; Li, Min-Chung

    2003-01-01

    Composite pressure vessels, used extensively for gas and fuel containment in space vehicles, are generally constructed with a metallic liner, while the fiber reinforcement carries the major portion of the pressure-induced load. The design is dominated by the liner s low strain at yield since the reinforcing fibers cannot operate at their potential load-bearing capability without resorting to pre-stressing (or autofrettaging). An ultra high-efficiency pressure vessel, which operates at the optimum strain capability of the fibers, can be potentially achieved with a liner-less construction. This paper discusses the design and manufacturing challenges to be overcome in the development of such a pressure vessel. These include: (1) gas/liquid containment and permeation, (2) design and structural analysis, and (3) manufacturing process development. The paper also presents the development and validation tests on a liner-less pressure vessel developed by Kaiser Compositek Inc. (KCI). It should be noted that KCI s liner-less tank exhibits a highly controlled leak-before-burst mode. This feature results in a structure having the highest level of safety.

  3. Performance of a Checkerboard Liner With Uncertain Impedances

    NASA Technical Reports Server (NTRS)

    Robinson, J. H.; Watson, W. R.

    2005-01-01

    The current fleet of large commercial aircraft has successfully achieved FAA noise certifications because of, in part, the successful application of uniform passive duct liner treatments to control engine system noise. One goal of NASA's engine system noise reduction program is to develop technologies to improve the sound absorbing properties of duct liner treatments so that they remain effective in modern turbo fan engines. One such technology being studied is checkerboard or periodic axially and circumferentially segmented liners. A preliminary assessment of the potential of this technology was conducted by applying uncertainties associated with manufacturing, installation, source structure, and tonal frequency to a liner developed using deterministic design methods and generating a measure of improvement with respect to a uniform liner subjected to the same uncertainties. Deterministic design and analysis of the candidate checkerboard liner showed that it obtains a 1.5 dB per duct aspect ratio improvement in liner attenuation over a similarly designed uniform liner. When uncertainties in liner impedances, source structure, and frequency are considered, the performance of the checkerboard liner drops off dramatically. The final results of this paper show that the candidate checkerboard liner has a less than 25 percent chance of outperforming the uniform liner when moderate levels of uncertainty are considered. It is important to note that this study did not include the effects of mean flow on liner performance and, more important to note, that as a gradient based optimization process was used to design the checkerboard liner, it is almost certain that a global optimal design was not found for the candidate checkerboard liner. Had it been possible to find a better deterministically performing checkerboard liner, the probability that this candidate liner would outperform the uniform liner would certainly have been higher.

  4. Mixed metal hydroxycarboxylic acid complexes. Spectrophotometric study of complexes of U(VI) with In(III), Cu(II), Zn(II) and Cd(II)

    SciTech Connect

    Manzurola, E.; Apelblat, A.; Markovits, G.; Levy, O. )

    1988-01-01

    The formation of mixed metal complexes between uranium (VI), as the central metal ion, and aluminum (III), indium (III), copper (II), zinc (II) and cadmium (II), as the additional metal ions, with a hydroxycarboxylic acid chosen between citric, tartaric or malic, has been studied using spectrophotometric methods. The effect of pH has been examined, and the results show that at pH = 4 stable complexes are formed for most of the systems. At this pH the method of mole ratio and Job's method of continuous variations, were employed to determine the stoichiometry of the mixed metal complexes. Al(III), In(III) and Cu(II) showed a high tendency to form mixed metal complexes with U(VI), while the formation of complexes is uncertain for Cd(II) and Zn(II). The ratio of the ligand to the total metal ion has been found to be 2:1 and metal:metal ratios of 1:1 and 1:2 have been observed.

  5. Changes in near-surface microstructure of metallic limiters following one year of service in doublet III

    NASA Astrophysics Data System (ADS)

    Trester, P. W.; Sevier, D. L.; Sabado, M. M.

    The structural alloys Ta-10W, Mo, and Inconel X-750 were used for plasma limiters during the 3-MW ohmic heating experiments of the Doublet III (DIII) tokamak. Post-service examinations of these limiters are reviewed. Near-surface melting, cracking, and microstructural changes are shown and discussed. During DIII service, elements from other metallic components were transported by the plasma and deposited on the limiter surface; significantly, high concentrations of Ni, Fe, Mo and C were detected in the regions found to be microcracked in the Ta-10W. Observations and analyses are made that are relevant to the design of limiter and armor components for larger tokamaks.

  6. Impact of two iron(III) chelators on the iron, cadmium, lead and nickel accumulation in poplar grown under heavy metal stress in hydroponics.

    PubMed

    Mihucz, Victor G; Csog, Árpád; Fodor, Ferenc; Tatár, Enikő; Szoboszlai, Norbert; Silaghi-Dumitrescu, Luminiţa; Záray, Gyula

    2012-04-15

    Poplar (Populus jacquemontiana var. glauca cv. Kopeczkii) was grown in hydroponics containing 10 μM Cd(II), Ni(II) or Pb(II), and Fe as Fe(III) EDTA or Fe(III) citrate in identical concentrations. The present study was designed to compare the accumulation and distribution of Fe, Cd, Ni and Pb within the different plant compartments. Generally, Fe and heavy-metal accumulation were higher by factor 2-7 and 1.6-3.3, respectively, when Fe(III) citrate was used. Iron transport towards the shoot depended on the Fe(III) chelate and, generally, on the heavy metal used. Lead was accumulated only in the root. The amounts of Fe and heavy metals accumulated by poplar were very similar to those of cucumber grown in an identical way, indicating strong Fe uptake regulation of these two Strategy I plants: a cultivar and a woody plant. The Strategy I Fe uptake mechanism (i.e. reducing Fe(III) followed by Fe(II) uptake), together with the Fe(III) chelate form in the nutrient solution had significant effects on Fe and heavy metal uptake. Poplar appears to show phytoremediation potential for Cd and Ni, as their transport towards the shoot was characterized by 51-54% and 26-48% depending on the Fe(III) supply in the nutrient solution.

  7. Crystal structure of hydrazine iron(III) phosphate, the first transition metal phosphate containing hydrazine.

    PubMed

    David, Renald

    2015-12-01

    The title compound, poly[(μ2-hydrazine)(μ4-phosphato)iron(III)], [Fe(PO4)(N2H4)] n , was prepared under hydro-thermal conditions. Its asymmetric unit contains one Fe(III) atom located on an inversion centre, one P atom located on a twofold rotation axis, and two O, one N and two H atoms located on general positions. The Fe(III) atom is bound to four O atoms of symmetry-related PO4 tetra-hedra and to two N atoms of two symmetry-related hydrazine ligands, resulting in a slightly distorted FeO4N2 octa-hedron. The crystal structure consists of a three-dimensional hydrazine/iron phoshate framework whereby each PO4 tetra-hedron bridges four Fe(III) atoms and each hydrazine ligand bridges two Fe(III) atoms. The H atoms of the hydrazine ligands are also involved in moderate N-H⋯O hydrogen bonding with phosphate O atoms. The crystal structure is isotypic with the sulfates [Co(SO4)(N2H4)] and [Mn(SO4)(N2H4)].

  8. Crystal structure of hydrazine iron(III) phosphate, the first transition metal phosphate containing hydrazine

    PubMed Central

    David, Renald

    2015-01-01

    The title compound, poly[(μ2-hydrazine)(μ4-phosphato)iron(III)], [Fe(PO4)(N2H4)]n, was prepared under hydro­thermal conditions. Its asymmetric unit contains one FeIII atom located on an inversion centre, one P atom located on a twofold rotation axis, and two O, one N and two H atoms located on general positions. The FeIII atom is bound to four O atoms of symmetry-related PO4 tetra­hedra and to two N atoms of two symmetry-related hydrazine ligands, resulting in a slightly distorted FeO4N2 octa­hedron. The crystal structure consists of a three-dimensional hydrazine/iron phoshate framework whereby each PO4 tetra­hedron bridges four FeIII atoms and each hydrazine ligand bridges two FeIII atoms. The H atoms of the hydrazine ligands are also involved in moderate N—H⋯O hydrogen bonding with phosphate O atoms. The crystal structure is isotypic with the sulfates [Co(SO4)(N2H4)] and [Mn(SO4)(N2H4)]. PMID:26870399

  9. Metal-Ion-Triggered Exonuclease III Activity for the Construction of DNA Colorimetric Logic Gates.

    PubMed

    Gao, Wan; Zhang, Li; Liang, Ru-Ping; Qiu, Jian-Ding

    2015-10-19

    The logic system is obtained by using a series of double-stranded (ds) DNA templates with mismatched base pairs (T-T or C-C) and ion-modulated exonuclease III (Exo III) activity, in which the Exo III cofactors, Hg(2+) and Ag(+) ions, are used as inputs for the activation of the respective scission of Exo III based on the formation of T-Hg(2+) -T or C-Ag(+) -C base pairs. Additionally, two kinds of signal probes are utilized to transduce the logic operations. One is the two split G-rich DNA strands that are used to design the OR, AND, INHIBIT, and XOR gates, whereas the other is the self-assembled split G-quadruplex structure to construct NOR, NAND, IMPLICATION, and XNOR operations based on DNA hybridization and strand displacement. In the presence of hemin, the split G-quadruplex biocatalyzes the formation of a colored product, which is an output signal for the different logic gates. Thus, we have constructed a complete set of colorimetric DNA logic gates based on the Exo III and split G-quadruplex for the first time. In addition, we are able to effortlessly recognize the logic output signals by the naked eye and their simplicity and cost-effective design is the most apparent feature for the logic gates developed in this work. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Diiron(III)-μ-Fluoro Bisporphyrins: Effect of Bridging Ligand on the Metal Spin State.

    PubMed

    Sil, Debangsu; Kumar, Amit; Rath, Sankar Prasad

    2016-08-01

    A hitherto unknown family of diiron(III)-μ-fluoro bisporphyrins has been synthesized and structurally characterized. Fluoride abstraction from SbF6 (-) and BF4 (-) resulted in the synthesis of the μ-fluoro complexes of ethane- and ethene-bridged diiron(III) bisporphyrins. Two such complexes were structurally characterized, which revealed a single fluoro bridge between two iron centers with a remarkably bent Fe-F-Fe unit. Although isoelectronic with the μ-hydroxo complexes, the μ-fluoro species are quite divergent in terms of the electronic structure and properties. UV/Vis spectroscopy of the μ-fluoro complex exhibits a large redshift (ca. 18 nm) of the Soret band in comparison to their μ-hydroxo analog. Combined analysis by single crystal X-ray structure determination and Mössbauer and (1) H NMR spectroscopy revealed the presence of two equivalent iron(III) centers in the μ-fluoro complexes in both solid and solution phases. In contrast, the iron(III) centers of the μ-hydroxo complexes are known to be inequivalent. Variable-temperature magnetic studies show a weak antiferromagnetic interaction between the iron(III) centers of the μ-fluoro complexes with coupling constants (J) ranging from -33 to -40 cm(-1) . The experimental results were further supported by DFT calculations.

  11. The GIRAFFE Inner Bulge Survey (GIBS). III. Metallicity distributions and kinematics of 26 Galactic bulge fields

    NASA Astrophysics Data System (ADS)

    Zoccali, M.; Vasquez, S.; Gonzalez, O. A.; Valenti, E.; Rojas-Arriagada, A.; Minniti, J.; Rejkuba, M.; Minniti, D.; McWilliam, A.; Babusiaux, C.; Hill, V.; Renzini, A.

    2017-02-01

    Context. Several recent studies have demonstrated that the Galactic bulge hosts two components with different mean metallicities, and possibly different spatial distribution and kinematics. As a consequence, both the metallicity distribution and the radial velocity of bulge stars vary across different lines of sight. Aims: We present here the metallicity distribution function of red clump stars in 26 fields spread across a wide area of the bulge, with special emphasis on fields close to Galactic plane, at latitudes b = -2° and b = -1°, that have not been explored before. Methods: This paper includes new metallicities from a sample of approximately 5000 K giant stars, observed at spectral resolution R 6500, in the Calcium II Triplet region. These represent the main dataset from the GIRAFFE Inner Bulge Survey. As part of the same survey we have previously published results for a sample of approximately 600 K giant stars, at latitude b -4°, derived from higher resolution spectra (R = 22 500). Results: The combined sample allows us to trace and characterize the metal poor and metal rich bulge populations down to the inner bulge. We present a density map for each of the two components. Contrary to expectations from previous works, we found the metal poor population to be more centrally concentrated than the metal rich one, and with a more axisymmetric spatial distribution. The metal rich population, on the other hand, is arranged in a boxy distribution, consistent with an edge-on bar. By coupling metallicities and radial velocities we show that the metal poor population has a velocity dispersion that varies rather mildly with latitude. On the contrary, the metal rich population has a low velocity dispersion far from the plane (b = -8.5°), yet has a steeper gradient with latitude, becoming higher than the metal poor one in the innermost field (b = -1°). Conclusions: This work provides new observational constraints on the actual chemodynamical properties of the

  12. Plasma-Jet-Driven Magneto-Inertial Fusion (PJMIF): Physics and Design for a Plasma Liner Formation Experiment

    NASA Astrophysics Data System (ADS)

    Hsu, Scott; Cassibry, Jason; Witherspoon, F. Douglas

    2014-10-01

    Spherically imploding plasma liners are a potential standoff compression driver for magneto-inertial fusion, which is a hybrid of and operates in an intermediate density between those of magnetic and inertial fusion. We propose to use an array of merging supersonic plasma jets to form a spherically imploding plasma liner. The jets are to be formed by pulsed coaxial guns with contoured electrodes that are placed sufficiently far from the location of target compression such that no hardware is repetitively destroyed. As such, the repetition rate can be higher (e.g., 1 Hz) and ultimately the power-plant economics can be more attractive than most other MIF approaches. During the R&D phase, a high experimental shot rate at reasonably low cost (e.g., < 1 k/shot) may be achieved with excellent diagnostic access, thus enabling a rapid learning rate. After some background on PJMIF and its prospects for reactor-relevant energy gain, this poster describes the physics objectives and design of a proposed 60-gun plasma-liner-formation experiment, which will provide experimental data on: (i) scaling of peak liner ram pressure versus initial jet parameters, (ii) liner non-uniformity characterization and control, and (iii) control of liner profiles for eventual gain optimization.

  13. TEM Observation of Martensite Layer at the Weld Interface of an A508III to Inconel 82 Dissimilar Metal Weld Joint

    NASA Astrophysics Data System (ADS)

    Chen, Z. R.; Lu, Y. H.

    2015-12-01

    A lenticular martensite layer at the weld interface in an A508III/Inconel 82 dissimilar metal weld (DMW) joint was studied by TEM. The martensite/weld metal boundary was observed as the fusion boundary. There was a K-S orientation relationship between martensite and weld metal. The formation of the martensite was mainly determined by the distribution of alloy elements. The martensite was responsible for the hardness peak in the DMW.

  14. Metal-organic porous frameworks designed from zinc(II), terbium(III), europium(III), and organic carboxylate building blocks

    NASA Astrophysics Data System (ADS)

    Reineke, Theresa Marie

    The body of this thesis focuses on constructing novel, metal-organic open framework (MOF) materials by the copolymerization in solution of Zn(II), Tb(III) Eu(III) metal ions with the organic building blocks: acetylenedicarboxylic acid (ADC), 4,4'-bipyridine (BPY), 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), 2,6-naphthalenedicarboxylic acid (NDC), 4,4'-azodibenzoic acid (ADC), 1,3,5,7-adamantanetetracarboxylic acid (ATC), and 1,4-benzenedicarboxylic acid (BDC). Several new open structures with the formulas Th(BDC)(NO 3)·[HCON(CH3)2]2 (MOF6 ), Th2(BDC)Y(H2O)4 (MOF-7), Tb 2(ADC)3·(CH3OH)2[(CH3) 2SO]2 (MOF-8), Tb2(ADB)3·[(CH 3)2SO]20 (MOF-9), Zn(ADC)2·[BN(CH 2CH3)3]2 (MOF-10), Zn 2(ATC)·(H2O)2(CH3Ch2OH) 2 (MOF-12), and Zn(NDC)·(H2O)[HCON(CH3) 2](C6H5Cl)0.5 (INSOFAR) have been characterized through single crystal x-ray diffraction. Other non porous crystal structures have also been characterized: Zn(ADC)(H2O)[HCON(CH3) 2], Eu(NO3)4 (BPY)(HBPY), and Tb(HEDP)2(C 5H5N), and the preparation of these structures have been compared to the synthesis of the porous structures. In addition, the properties, porosity, and inclusion chemistry of the MOFs have been explored by gas and liquid sorption, thermal gravimetric analysis, elemental analysis, Fourier transform infrared spectroscopy, and x-ray powder diffraction techniques. Several challenges in the area of MOF materials have been addressed in this work. By using solvo-thermal and room temperature vapor diffusion techniques, effective methods of synthesis and crystallization have been developed for these systems. By using the large amount of data available on Zn(II) chemistry, as well as the work of previous researchers in our group, many novel Zn(II) - carboxylate open frameworks can now be designed for certain structural attributes. This is accomplished through using known atom clusters or secondary building units (SBUs) of the metal ion employed in constructing the framework. Furthermore, by implementing this

  15. Polymer-Supported Optically Active fac(S)-Tris(thiotato)rhodium(III) Complex for Sulfur-Bridging Reaction With Precious Metal Ions.

    PubMed

    Aizawa, Sen-Ichi; Tsubosaka, Soshi

    2016-01-01

    The optically active mixed-ligand fac(S)-tris(thiolato)rhodium(III) complexes, ΔL -fac(S)-[Rh(aet)2 (L-cys-N,S)](-) (aet = 2-aminoethanethiolate, L-cys = L-cysteinate) () and ΔLL -fac(S)-[Rh(aet)(L-cys-N,S)2 ](2-) were newly prepared by the equatorial preference of the carboxyl group in the coordinated L-cys ligand. The amide formation reaction of with 1,10-diaminodecane and polyallylamine gave the diamine-bridged dinuclear Rh(III) complex and the single-chain polymer-supported Rh(III) complex with retention of the ΔL configuration of , respectively. These Rh(III) complexes reacted with Co(III) or Co(II) to give the linear-type trinuclear structure with the S-bridged Co(III) center and the two Δ-Rh(III) terminal moieties. The polymer-supported Rh(III) complex was applied not only to the CD spectropolarimetric detection and determination of a trace of precious metal ions such as Au(III), Pt(II), and Pd(II) but also to concentration and extraction of these metal ions into the solid polymer phase. Chirality 28:85-91, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  16. Use of FGD as an impervious liner

    SciTech Connect

    Wolfe, W.E.; Butalia, T.S.

    1998-07-01

    Increasing generation of coal combustion products (CCPs), particularly flue gas desulfurization (FGD) material, has led utilities to look for beneficial uses of these products. This paper presents one such utilization application of CCPs, i.e., the use of FGD material as an impervious liner for ponds and lagoons. The construction of a full scale lagoon using compacted FGD as a liner is presented. The project was undertaken primarily to address two critical questions, (1) what is the quality of water that permeates through an FGD liner and (2) what is the quantity of water permeating through a field compacted FGD fill of known thickness? The effects of construction processes on the behavior of compacted FGD are evaluated. The monitoring of the performance of the lagoon liner is discussed. Preliminary results indicate that the permeability of the field compacted FGD liner is reducing with time and is approaching the EPA recommended value of 1 x 10{sup {minus}7} cm/sec for waste containment facilities.

  17. Use of FGD as an impervious liner

    SciTech Connect

    Wolfe, W.E.; Butalia, T.S.

    1998-04-01

    Increasing generation of coal combustion products (CCPs), particularly flue gas desulfurization (FGD) material, has led utilities to look for beneficial uses of these products. This paper presents one such utilization application of CCPs, i.e., the use of FGD material as an impervious liner for ponds and lagoons. The construction of a full scale lagoon using compacted FGD as a liner is presented. The project was undertaken primarily to address two critical questions, (1) what is the quality of water that permeates through an FGD liner and (2) what is the quantity of water permeating through a field compacted FGD fill of known thickness? The effects of construction processes on the behavior of compacted FGD are evaluated. The monitoring of the performance of the lagoon liner is discussed. Preliminary results indicate that the permeability of the field compacted FGD liner is reducing with time and is approaching the EPA recommended value of 1x10{sup -7} cm/sec for waste containment facilities.

  18. Effect of liner thickness on electromigration lifetime

    NASA Astrophysics Data System (ADS)

    Liniger, E. G.; Hu, C.-K.; Gignac, L. M.; Simon, A.

    2003-06-01

    Electromigration lifetime was measured as a function of liner thickness for Cu/SiO2 interconnect structures. A significant increase in mean lifetime was observed for structures in which the liner thickness at the base of the test via was less than approximately 6 nm, with a current density <5 mA/μm2 in the power line connected to the test via. This is attributed to the continuous flow of Cu across the thin and possibly discontinuous liner at the base of the via. For extremely thin liner coverage, <1.4 nm at the base of the via and 2.5 at the bottom of the test line, the mean lifetime was observed to decrease as a rapid diffusion path was created which partially offset the beneficial effects of continuous flow. Failure distributions appeared to be trimodal and this was confirmed through failure analysis. In the case of thin liner coverage (<6 nm), early fails, which are typically characterized by slitlike voids at the via/line interface, were not observed.

  19. The FIR Emission and [CII] in LINERs

    NASA Astrophysics Data System (ADS)

    Masegosa, J.; Márquez, I.; Sempere, M. J.; Cernicharo, J.

    2001-07-01

    LINERs galaxies have been considered as the low level end of the family of Active Galactic Nuclei (AGNs). But a lack of consensus does still exist on the nature of these galaxies. Some of them show clear evidences for an AGN nature whereas data at different frequencies seem to support an Starburst origin as the responsible of their observed properties. The general properties at FIR of LINERs have not been properly studied. Among the LINERs reported in the multifrequency catalogue by Carrillo, Masegosa et al. (1999) 335 have been observed with IRAS. In this paper we present a preliminary analysis of these data. The most relevant result obtained so far is that the 12 microns emission is associated with the cold disk dust emission. The ISO database have been used to search for all the LINERs observed with the Long Wavelength Spectrograph looking for C+ detections. In 27 galaxies out of the 69 LINERs observed with ISO the [CII]λ 158 microns has been measured. The main conclussion from this analysis is that C+ is not related to the recent star formation events but instead it seems to be associated to the PDRs in giant molecular clouds.

  20. The Halo Stars in NGC 5128. III. An Inner Halo Field and the Metallicity Distribution

    NASA Astrophysics Data System (ADS)

    Harris, William E.; Harris, Gretchen L. H.

    2002-06-01

    We present new Hubble Space Telescope WFPC2 (V,I) photometry for field stars in NGC 5128 at a projected distance of 8 kpc from the galaxy center, which probes a mixture of its inner halo and outer bulge. The color-magnitude diagram shows an old red giant branch that is even broader in color than our two previously studied outer halo fields (at 21 and 31 kpc), with significant numbers of stars extending to solar metallicity and higher. The peak frequency of the metallicity distribution function (MDF) is at [m/H]~=-0.4, with even fewer metal-poor stars than in the outer halo fields. If we use the 21 and 31 kpc fields to define template ``halo'' MDFs and subtract these from the 8 kpc field, the residual ``bulge'' population has a mean [m/H]~=-0.2, similar to the bulges of other large spiral and elliptical galaxies. We find that the main features of the halo MDF can be reproduced by a simple chemical evolution model in which early star formation goes on simultaneously with an initial stage of rapid infall of very metal-poor gas, after which the infall dies away exponentially. Finally, by comparison with the MDFs for the NGC 5128 globular clusters, we find that in all the halo fields we have studied there is a clear decrease of specific frequency SN (number of clusters per unit halo light) with increasing metallicity. At the lowest-metallicity range ([Fe/H]<-1.6) SN is ~4-8, while at metallicities [Fe/H]>-1 it has dropped to ~=1.5. This trend may indicate that globular cluster formation efficiency is a strong function of the metallicity of the protocluster gas. However, we suggest an alternate possibility, which is that globular clusters form preferentially sooner than field stars. If most of the cluster formation within a host giant molecular cloud takes place sooner than most of the distributed field-star formation and if the earliest most metal-poor star-forming clouds are prematurely disrupted by their own first bursts of star formation, then they would leave

  1. Heterogeneous catalytic oxidation of As(III) on nonferrous metal oxides in the presence of H2O2.

    PubMed

    Kim, Dong-hyo; Bokare, Alok D; Koo, Min suk; Choi, Wonyong

    2015-03-17

    The oxidation of As(III) (arsenite) to As(V) (arsenate), a critical pretreatment process for total arsenic removal, is easily achieved using chemical oxidation methods. Hydrogen peroxide (H2O2) is widely used as an environmentally benign oxidant but its practical use for the arsenite oxidation is limited by the strong pH dependence and slow oxidation kinetics. This study demonstrated that H2O2-induced oxidation of As(III) can be markedly enhanced in the presence of nonferrous metal oxides (e.g., WO3, TiO2, ZrO2) as a heterogeneous catalyst working over a wide pH range in ambient reaction conditions. In particular, TiO2 is an ideal catalyst because it is not only active and stable but also easily available and inexpensive. Although the photocatalytic oxidation of As(III) on TiO2 was intensively studied, the thermal catalytic activities of TiO2 and other nonferrous metal oxides for the arsenic oxidation have been little investigated. The heterogeneous oxidation rate increased with increasing the TiO2 surface area and [H2O2] and weakly depended on pH whereas the homogeneous oxidation by H2O2 alone was favored only at alkaline condition. The oxidation rate in the TiO2/H2O2 system was not reduced at all in the absence of dioxygen. It was not retarded at all by OH radical scavengers but markedly inhibited by hydroperoxyl radical scavengers. It is proposed that the surface complexation of H2O2 on TiO2 induces the generation of the surface hydroperoxyl radical through an inner-sphere electron transfer, which subsequently reacts with As(III). The catalytic activity of TiO2 was maintained without showing any sign of deactivation. The heterogeneous catalytic oxidation is proposed as a viable method for the preoxidation treatment of As(III)-contaminated water under ambient conditions.

  2. Drag Measurements of Porous Plate Acoustic Liners

    NASA Technical Reports Server (NTRS)

    Wolter, John D.

    2005-01-01

    This paper presents the results of direct drag measurements on a variety of porous plate acoustic liners. The existing literature describes numerous studies of drag on porous walls with injection or suction, but relatively few of drag on porous plates with neither injection nor suction. Furthermore, the porosity of the porous plate in existing studies is much lower than typically used in acoustic liners. In the present work, the acoustic liners consisted of a perforated face sheet covering a bulk acoustic absorber material. Factors that were varied in the experiment were hole diameter, hole pattern, face sheet thickness, bulk material type, and size of the gap (if any) between the face sheet and the absorber material.

  3. FOAM-IN-PLACE FORM FITTING HELMET LINERS

    DTIC Science & Technology

    A urethane foam formulation has been developed to produce foamed-in-place helmet liners for Air Force crash or flying helmets. High density urethane...foam helmet liners has been foamed-in-place directly on the flying crew member’s head, producing a perfectly fitting helmet liner with a minimum of...time, labor and inconvenience. These liners were produced at an extremely modest cost. Design and fabrication of a suitable mold in which the helmet

  4. Assessing liner performance using on-farm milk meters.

    PubMed

    Penry, J F; Leonardi, S; Upton, J; Thompson, P D; Reinemann, D J

    2016-08-01

    The primary objective of this study was to quantify and compare the interactive effects of liner compression, milking vacuum level, and pulsation settings on average milk flow rates for liners representing the range of liner compression of commercial liners. A secondary objective was to evaluate a methodology for assessing liner performance that can be applied on commercial dairy farms. Eight different liner types were assessed using 9 different combinations of milking system vacuum and pulsation settings applied to a herd of 80 cows with vacuum and pulsation conditions changed daily for 36d using a central composite experimental design. Liner response surfaces were created for explanatory variables milking system vacuum (Vsystem) and pulsator ratio (PR) and response variable average milk flow rate (AMF=total yield/total cups-on time) expressed as a fraction of the within-cow average flow rate for all treatments (average milk flow rate fraction, AMFf). Response surfaces were also created for between-liner comparisons for standardized conditions of claw vacuum and milk ratio (fraction of pulsation cycle during which milk is flowing). The highest AMFf was observed at the highest levels of Vsystem, PR, and overpressure. All liners showed an increase in AMF as milking conditions were changed from low to high standardized conditions of claw vacuum and milk ratio. Differences in AMF between liners were smallest at the most gentle milking conditions (low Vsystem and low milk ratio), and these between-liner differences in AMF increased as liner overpressure increased. Differences were noted with vacuum drop between Vsystem and claw vacuum depending on the liner venting system, with short milk tube vented liners having the greater vacuum drop than mouthpiece chamber vented liners. The accuracy of liner performance assessment in commercial parlors fitted with milk meters can be improved by using a central composite experimental design with a repeated center point treatment

  5. Advanced liner-cooling techniques for gas turbine combustors

    NASA Technical Reports Server (NTRS)

    Norgren, C. T.; Riddlebaugh, S. M.

    1985-01-01

    Component research for advanced small gas turbine engines is currently underway at the NASA Lewis Research Center. As part of this program, a basic reverse-flow combustor geometry was being maintained while different advanced liner wall cooling techniques were investigated. Performance and liner cooling effectiveness of the experimental combustor configuration featuring counter-flow film-cooled panels is presented and compared with two previously reported combustors featuring: splash film-cooled liner walls; and transpiration cooled liner walls (Lamilloy).

  6. SDU6 Interior Liner Testing & Evaluation

    SciTech Connect

    Skidmore, T. E.

    2016-10-14

    Two liner materials (Marseal® M-3500 and REMA Chemoline® 4CN) proposed for use as a liner inside the Saltstone Disposal Unit 6 (SDU6) were subjected to specific ASTM tests (tensile and lap-shear) after immersion in 50% and 100% simulant solutions for 1000 hours at the Savannah River Ecology Laboratory. Both liner materials exhibited good resistance to the simulant chemistry, at least based on the tests performed and the test duration/conditions imposed. In lap-shear tests, both materials failed in the base material rather than peeling apart, confirming good adhesion. The REMA 4CN bromobutyl elastomer showed superior bonding characteristics and absence of warping or delamination at the conditions tested. The Marseal M-3500 material (PVC/EVA blend with polyester reinforcement) exhibited deformation and debonding in some locations. The cause of the deformation and delamination observed in the Marseal M-3500 material is not fully known, but possibly attributed to thermomechanical stress at immersion temperatures, and the thermoplastic nature of the material. The immersion temperature (68 °C) is slightly greater than the maximum use temperature limit quoted for the Marseal M- 3500 liner (65 °C), though the basis for the service limit is unknown. The testing performed was limited in scope and only for these two liner materials. These tests were primarily performed to screen for severe incompatibility or short-term degradation in Saltstone bleedwater simulants at bounding solution temperatures. Additional testing is recommended to assess long-term performance and the overall service life of the liner.

  7. Lifecycle Verification of Tank Liner Polymers

    SciTech Connect

    Anovitz, Lawrence {Larry} M; Smith, Barton

    2014-03-01

    This report describes a method that was developed for the purpose of assessing the durability of thermoplastic liners used in a Type IV hydrogen storage tank during the tank s expected service life. In the method, a thermoplastic liner specimen is cycled between the maximum and minimum expected working temperatures while it is differentially pressurized with high-pressure hydrogen gas. The number of thermal cycling intervals corresponds to those expected within the tank s design lifetime. At prescribed intervals, hydrogen permeation measurements are done in situ to assess the ability of the liner specimen to maintain its hydrogen barrier properties and to model its permeability over the tank lifetime. Finally, the model is used to assess whether the steady-state leakage rate in the tank could potentially exceed the leakage specification for hydrogen fuel cell passenger vehicles. A durability assessment was performed on a specimen of high-density polyethylene (HDPE) that is in current use as a tank liner. Hydrogen permeation measurements were performed on several additional tank liner polymers as well as novel polymers proposed for use as storage tank liners and hydrogen barrier materials. The following technical barriers from the Fuel Cell Technologies Program MYRDD were addressed by the project: D. Durability of on-board storage systems lifetime of at least 1500 cycles G. Materials of construction vessel containment that is resistant to hydrogen permeation M. Lack of Tank Performance Data and Understanding of Failure Mechanisms And the following technical targets1 for on-board hydrogen storage systems R&D were likewise addressed: Operational cycle life (1/4 tank to full) FY 2017: 1500 cycles; Ultimate: 1500 cycles Environmental health & safety Permeation and leakage: Meets or exceeds applicable standards Loss of useable H2: FY 2017: 0.05 g/h/kg H2; Ultimate: 0.05 g/h/kg H2

  8. Acoustic Panel Liner for an Engine Nacelle

    NASA Technical Reports Server (NTRS)

    Jones, Michael G. (Inventor); Nark, Douglas M. (Inventor); Ayle, Earl (Inventor); Ichihashi, Fumitaka (Inventor)

    2016-01-01

    An acoustic panel liner includes a face sheet, back plate, and liner core positioned there-between, which may be used in an engine nacelle. Elongated chambers contain variable amounts of septa at a calibrated depth or depths. The septa may have varying DC flow resistance. The chambers may have a hexagonal or other polygonal cross sections. The septa, such as mesh caps, may be bonded to an inner wall of a corresponding chamber. The insertion depths may be the same or different. If different, the pattern of distribution of the depths may be randomized.

  9. Tank 241-AY-102 Secondary Liner Corrosion Evaluation - 14191

    SciTech Connect

    Boomer, Kayle D.; Washenfelder, Dennis J.; Johnson, Jeremy M.

    2014-01-07

    In October 2012, Washington River Protection Solutions, LLC (WRPS) determined that the primary tank of 241-AY-102 (AY-102) was leaking. A number of evaluations were performed after discovery of the leak which identified corrosion from storage of waste at the high waste temperatures as one of the major contributing factors in the failure of the tank. The propensity for corrosion of the waste on the annulus floor will be investigated to determine if it is corrosive and must be promptly removed or if it is benign and may remain in the annulus. The chemical composition of waste, the temperature and the character of the steel are important factors in assessing the propensity for corrosion. Unfortunately, the temperatures of the wastes in contact with the secondary steel liner are not known; they are estimated to range from 45 deg C to 60 deg C. It is also notable that most corrosion tests have been carried out with un-welded, stress-relieved steels, but the secondary liner in tank AY-102 was not stress-relieved. In addition, the cold weather fabrication and welding led to many problems, which required repeated softening of the metal to flatten secondary bottom during its construction. This flame treatment may have altered the microstructure of the steel.

  10. Stress-Corrosion Cracking of Metallic Materials. Part III. Hydrogen Entry and Embrittlement in Steel

    DTIC Science & Technology

    1975-04-01

    Memorial Lecture), Trans. ASM, 52 (1960), 54. 3. Bastein, P., and Azou , P., "Effect of Hydrogen on the Deformation and Fracture of Iron and Steel in Simple...Embrittlemnent in Iron and Steels," Fydrogen in Metals, International Conference in Paris, (May-June, 1972), 144h 1C5. Bastein, 11., and Azou , P., Rev

  11. Low-metallicity Star Formation and Pop III-II Transition

    NASA Astrophysics Data System (ADS)

    Omukai, Kazuyuki

    2010-10-01

    The first stars in the universe were typically very massive, but those near us are not. The metallicity in the star-forming gas is thought to have played a key role in this transition of characteristic stellar mass scale. By studying the evolution of low-metallicity star-forming clouds up to the formation of protostars by way of radiation hydrodynamics with spherical symmetry, we discuss their fragmentation mass scales. The critical metallicity for low-mass fragmentation is in the range of Zcr = 10-6-10-5Zsolar. Although the exact value is still unknown due to uncertain dust nature in the early universe, the small value of Zcr means that low-mass star formation begun just after the first episode of metal enrichment. We also evaluate the upper limit on the stellar mass by the stellar feedback. Owing to the higher density in the envelope and thus higher protostellar accretion rate, the upper limit of stellar mass increases toward lower matallicity.

  12. Inductively Driven, 3D Liner Compression of a Magnetized Plasma to Megabar Energy Densities

    SciTech Connect

    Slough, John

    2015-02-01

    To take advantage of the smaller scale, higher density regime of fusion an efficient method for achieving the compressional heating required to reach fusion gain conditions must be found. What is proposed is a more flexible metallic liner compression scheme that minimizes the kinetic energy required to reach fusion. It is believed that it is possible to accomplish this at sub-megajoule energies. This however will require operation at very small scale. To have a realistic hope of inexpensive, repetitive operation, it is essential to have the liner kinetic energy under a megajoule which allows for the survivability of the vacuum and power systems. At small scale the implosion speed must be reasonably fast to maintain the magnetized plasma (FRC) equilibrium during compression. For limited liner kinetic energy, it becomes clear that the thinnest liner imploded to the smallest radius consistent with the requirements for FRC equilibrium lifetime is desired. The proposed work is directed toward accomplishing this goal. Typically an axial (Z) current is employed for liner compression. There are however several advantages to using a θ-pinch coil. With the θ-pinch the liner currents are inductively driven which greatly simplifies the apparatus and vacuum system, and avoids difficulties with the post implosion vacuum integrity. With fractional flux leakage, the foil liner automatically provides for the seed axial compression field. To achieve it with optimal switching techniques, and at an accelerated pace however will require additional funding. This extra expense is well justified as the compression technique that will be enabled by this funding is unique in the ability to implode individual segments of the liner at different times. This is highly advantageous as the liner can be imploded in a manner that maximizes the energy transfer to the FRC. Production of shaped liner implosions for additional axial compression can thus be readily accomplished with the modified power

  13. Dynamic Response and Residual Helmet Liner Crush Using Cadaver Heads and Standard Headforms.

    PubMed

    Bonin, S J; Luck, J F; Bass, C R; Gardiner, J C; Onar-Thomas, A; Asfour, S S; Siegmund, G P

    2017-03-01

    Biomechanical headforms are used for helmet certification testing and reconstructing helmeted head impacts; however, their biofidelity and direct applicability to human head and helmet responses remain unclear. Dynamic responses of cadaver heads and three headforms and residual foam liner deformations were compared during motorcycle helmet impacts. Instrumented, helmeted heads/headforms were dropped onto the forehead region against an instrumented flat anvil at 75, 150, and 195 J. Helmets were CT scanned to quantify maximum liner crush depth and crush volume. General linear models were used to quantify the effect of head type and impact energy on linear acceleration, head injury criterion (HIC), force, maximum liner crush depth, and liner crush volume and regression models were used to quantify the relationship between acceleration and both maximum crush depth and crush volume. The cadaver heads generated larger peak accelerations than all three headforms, larger HICs than the International Organization for Standardization (ISO), larger forces than the Hybrid III and ISO, larger maximum crush depth than the ISO, and larger crush volumes than the DOT. These significant differences between the cadaver heads and headforms need to be accounted for when attempting to estimate an impact exposure using a helmet's residual crush depth or volume.

  14. Observations of altered instability structure for imploding z-pinch liners that are premagnetized with a uniform axial field

    NASA Astrophysics Data System (ADS)

    Awe, Thomas

    2013-10-01

    Magnetically driven implosions provide an energy-rich platform for inertial confinement fusion. The magnetized liner inertial fusion concept (MagLIF, Slutz et al., Phys. Plasmas 17, 056303 (2010)) uses a pulsed-power-driven metallic liner to compress and inertially confine preheated and premagnetized fusion fuel. The fuel is premagnetized with a uniform axial seed field Bz , 0 of 10 to 30 T, which is then compressed by the liner to nearly 1000 T. In the fuel, the ultra-high field reduces thermal conduction and enhances alpha-particle heating. Preheating the fuel to 100-300 eV eases requirements on liner-convergence; nonetheless, convergence ratios at stagnation of 20 or more may be necessary. The ability to maintain liner stability and uniformity through stagnation may ultimately determine the success of the MagLIF concept. The integrity of magnetically imploded liners is compromised both by electrode instabilities and by the magneto-Rayleigh Taylor (MRT) instability. Electrode instabilities form local perturbations that can mix liner material into the fuel prior to bulk compression. Recent experiments on the Z facility have shown that this instability is mitigated when the liner's ends implode onto a nylon ``cushion,'' which impedes local perturbation growth. Other recent experiments have, for the first time, studied the implosion dynamics of premagnetized (Bz , 0 > 0) MagLIF-type liners. When seeded with a 7 or 10 T axial field, these liners developed 3D-helix-like surface instabilities; such instabilities starkly contrast with the azimuthally-correlated MRT instabilities that have been consistently observed in many earlier unmagnetized (Bz , 0 = 0 T) experiments. Quite unexpectedly, the helical structure persisted throughout the implosion, even though the azimuthal drive field greatly exceeded the expected axial field at the liner surface for all but the earliest stages of the experiment. Thus far, no self-consistent model has reproduced this fundamentally 3D

  15. Ligand dependence of metal-metal bonding in the d(3)d(3) dimers M(2)X(9)(n-) (M(III) = Cr, Mo, W; M(IV) = Mn, Tc, Re; X = F, Cl, Br, I).

    PubMed

    Stranger, R; Turner, A; Delfs, C D

    2001-08-13

    The ligand dependence of metal-metal bonding in the d(3)d(3) face-shared M(2)X(9)(n-) (M(III) = Cr, Mo, W; M(IV) = Mn, Tc, Re; X = F, Cl, Br, I) dimers has been investigated using density functional theory. In general, significant differences in metal-metal bonding are observed between the fluoride and chloride complexes involving the same metal ion, whereas less dramatic changes occur between the bromide and iodide complexes and minimal differences between the chloride and bromide complexes. For M = Mo, Tc, and Re, change in the halide from F to I results in weaker metal-metal bonding corresponding to a shift from either the triple metal-metal bonded to single bonded case or from the latter to a nonbonded structure. A fragment analysis performed on M(2)X(9)(3-) (M = Mo, W) allowed determination of the metal-metal and metal-bridge contributions to the total bonding energy in the dimer. As the halide changes from F to I, there is a systematic reduction in the total interaction energy of the fragments which can be traced to a progressive destabilization of the metal-bridge interaction because of weaker M-X(bridge) bonding as fluoride is replaced by its heavier congeners. In contrast, the metal-metal interaction remains essentially constant with change in the halide.

  16. Oxidation behavior of Cr(III) during thermal treatment of chromium hydroxide in the presence of alkali and alkaline earth metal chlorides.

    PubMed

    Mao, Linqiang; Gao, Bingying; Deng, Ning; Liu, Lu; Cui, Hao

    2016-02-01

    The oxidation behavior of Cr(III) during the thermal treatment of chromium hydroxide in the presence of alkali and alkaline earth metal chlorides (NaCl, KCl, MgCl2, and CaCl2) was investigated. The amounts of Cr(III) oxidized at various temperatures and heating times were determined, and the Cr-containing species in the residues were characterized. During the transformation of chromium hydroxide to Cr2O3 at 300 °C approximately 5% of the Cr(III) was oxidized to form intermediate compounds containing Cr(VI) (i.e., CrO3), but these intermediates were reduced to Cr2O3 when the temperature was above 400 °C. Alkali and alkaline earth metals significantly promoted the oxidation of Cr(III) during the thermal drying process. Two pathways were involved in the influences the alkali and alkaline earth metals had on the formation of Cr(VI). In pathway I, the alkali and alkaline earth metals were found to act as electron transfer agents and to interfere with the dehydration process, causing more intermediate Cr(VI)-containing compounds (which were identified as being CrO3 and Cr5O12) to be formed. The reduction of intermediate compounds to Cr2O3 was also found to be hindered in pathway I. In pathway II, the alkali and alkaline earth metals were found to contribute to the oxidation of Cr(III) to form chromates. The results showed that the presence of alkali and alkaline earth metals significantly increases the degree to which Cr(III) is oxidized during the thermal drying of chromium-containing sludge.

  17. Medium-term results of cementation of a highly cross-linked polyethylene liner into a well-fixed acetabular shell in revision hip arthroplasty.

    PubMed

    Lim, Seung-Jae; Lee, Keun-Ho; Park, Shin-Hyung; Park, Youn-Soo

    2014-03-01

    The present study was undertaken to document outcomes of cementation of a highly cross-linked polyethylene (PE) liner into a well-fixed acetabular metal shell in 36 hips. All operations were performed by a single surgeon using only one type of liner. Patients were followed for a mean of 6.1 years (range, 3-8 years). Mean Harris hip score improved from 58 points preoperatively to 91 points postoperatively. There were no cases of PE liner dislodgement or progressive osteolysis. 1 hip (2.8%) required revision surgery for acetabular cup loosening with greater trochanteric fracture. Complications included 1 peroneal nerve palsy and 1 dislocation. The results of this study and previous reports demonstrated that cementation of highly cross-linked PE liner into well-fixed metal shell could provide good midterm durability.

  18. SERS and DFT investigation of 1-(2-pyridylazo)-2-naphthol and its metal complexes with Al(III), Mn(II), Fe(III), Cu(II), Zn(II) and Pb(II)

    NASA Astrophysics Data System (ADS)

    Szabó, László; Herman, Krisztian; Mircescu, Nicoleta E.; Fălămaş, Alexandra; Leopold, Loredana F.; Leopold, Nicolae; Buzumurgă, Claudia; Chiş, Vasile

    The development of surface-enhanced Raman scattering (SERS) as a prospective analytical methodology for detection of metal ions was shown in recent years by several studies on metal complexes. In this work, 1-(2-pyridylazo)-2-naphthol (PAN) and its Al(III), Mn(II), Fe(III), Cu(II), Zn(II) and Pb(II) complexes were studied by FTIR, FT-Raman and surface enhanced Raman spectroscopies. Molecular geometry optimization, molecular electrostatic potential (MEP) distribution and vibrational frequencies calculations were performed using the hybrid B3LYP exchange-correlation functional for the PAN molecule and its bidentate complexes. The calculated MEP distributions indicated the atoms with highest electronegativity, the adsorption to the silver surface occurring through these atoms. Based on experimental and theoretical data we were able to identify unique and representative features, useful for the identification of each PAN-metal complex.

  19. SERS and DFT investigation of 1-(2-pyridylazo)-2-naphthol and its metal complexes with Al(III), Mn(II), Fe(III), Cu(II), Zn(II) and Pb(II).

    PubMed

    Szabó, László; Herman, Krisztian; Mircescu, Nicoleta E; Fălămaş, Alexandra; Leopold, Loredana F; Leopold, Nicolae; Buzumurgă, Claudia; Chiş, Vasile

    2012-07-01

    The development of surface-enhanced Raman scattering (SERS) as a prospective analytical methodology for detection of metal ions was shown in recent years by several studies on metal complexes. In this work, 1-(2-pyridylazo)-2-naphthol (PAN) and its Al(III), Mn(II), Fe(III), Cu(II), Zn(II) and Pb(II) complexes were studied by FTIR, FT-Raman and surface enhanced Raman spectroscopies. Molecular geometry optimization, molecular electrostatic potential (MEP) distribution and vibrational frequencies calculations were performed using the hybrid B3LYP exchange-correlation functional for the PAN molecule and its bidentate complexes. The calculated MEP distributions indicated the atoms with highest electronegativity, the adsorption to the silver surface occurring through these atoms. Based on experimental and theoretical data we were able to identify unique and representative features, useful for the identification of each PAN-metal complex.

  20. Effects of heavy metals on the expression of a zinc-inducible metallothionein-III gene and antioxidant enzyme activities in Crassostrea gigas.

    PubMed

    Cong, Ming; Wu, Huifeng; Liu, Xiaoli; Zhao, Jianmin; Wang, Xuan; Lv, Jiasen; Hou, Lin

    2012-10-01

    Sequestration by metallothioneins and antioxidant defense are two kinds of important defense mechanisms employed by mollusks to minimize adverse effects caused by heavy metal contaminants in marine environment. In the present study, a novel metallothionein gene, CgMT-III, was cloned from Crassostrea gigas, consisting of eighteen conserved cysteine residues and encoding a MT III-like protein with two tandem β domains. The expression level of CgMT-III transcript induced by zinc was much higher than that induced by cadmium exposure. It suggested that CgMT-III was perhaps mainly involved in homeostatic control of zinc metabolism, which was distinct from previously identified MTs in C. gigas. Among the tested antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), SOD and GPx showed varying up-regulations in a tissue-specific manner, while CAT activities were inhibited in both gill and hepatopancreas from C. gigas exposed to heavy metals. It can be inferred that CgMT-III was mainly involved in zinc homeostasis, and CgMT-III gene together with CAT enzyme could be potential biomarkers to indicate heavy metal, especially zinc pollution in marine organisms.

  1. Highly efficient removal of heavy metals by polymer-supported nanosized hydrated Fe(III) oxides: behavior and XPS study.

    PubMed

    Pan, Bingjun; Qiu, Hui; Pan, Bingcai; Nie, Guangze; Xiao, Lili; Lv, Lu; Zhang, Weiming; Zhang, Quanxing; Zheng, Shourong

    2010-02-01

    The present study developed a polymer-based hybrid sorbent (HFO-001) for highly efficient removal of heavy metals [e.g., Pb(II), Cd(II), and Cu(II)] by irreversibly impregnating hydrated Fe(III) oxide (HFO) nanoparticles within a cation-exchange resin D-001 (R-SO(3)Na), and revealed the underlying mechanism based on X-ray photoelectron spectroscopy (XPS) study. HFO-001 combines the excellent handling, flow characteristics, and attrition resistance of conventional cation-exchange resins with the specific affinity of HFOs toward heavy metal cations. As compared to D-001, sorption selectivity of HFO-001 toward Pb(II), Cu(II), and Cd(II) was greatly improved from the Ca(II) competition at greater concentration. Column sorption results indicated that the working capacity of HFO-001 was about 4-6 times more than D-001 with respect to removal of three heavy metals from simulated electroplating water (pH approximately 4.0). Also, HFO-001 is particularly effective in removing trace Pb(II) and Cd(II) from simulated natural waters to meet the drinking water standard, with treatment volume orders of magnitude higher than D-001. The superior performance of HFO-001 was attributed to the Donnan membrane effect exerted by the host D-001 as well as to the impregnated HFO nanoparticles of specific interaction toward heavy metal cations, as further confirmed by XPS study on lead sorption. More attractively, the exhausted HFO-001 beads can be effectively regenerated by HCl-NaCl solution (pH 3) for repeated use without any significant capacity loss.

  2. Diagnostics for the plasma liner experiment.

    PubMed

    Lynn, A G; Merritt, E; Gilmore, M; Hsu, S C; Witherspoon, F D; Cassibry, J T

    2010-10-01

    The goal of the Plasma Liner Experiment (PLX) is to explore and demonstrate the feasibility of forming imploding spherical "plasma liners" via merging high Mach number plasma jets to reach peak liner pressures of ∼0.1 Mbar using ∼1.5 MJ of initial stored energy. Such a system would provide HED plasmas for a variety of fundamental HEDLP, laboratory astrophysics, and materials science studies, as well as a platform for experimental validation of rad-hydro and rad-MHD simulations. It could also prove attractive as a potential standoff driver for magnetoinertial fusion. Predicted parameters from jet formation to liner stagnation cover a large range of plasma density and temperature, varying from n(i)∼10(16) cm(-3), T(e)≈T(i)∼1 eV at the plasma gun mouth to n(i)>10(19) cm(-3), T(e)≈T(i)∼0.5 keV at stagnation. This presents a challenging problem for the plasma diagnostics suite which will be discussed.

  3. Precision solid liner experiments on Pegasus II

    SciTech Connect

    Bowers, R.L.; Brownell, J.H.; Lee, H.

    1995-09-01

    Pulsed power systems have been used in the past to drive solid liner implosions for a variety of applications. In combination with a variety of target configurations, solid liner drivers can be used to compress working fluids, produce shock waves, and study material properties in convergent geometry. The utility of such a driver depends in part on how well-characterized the drive conditions are. This, in part, requires a pulsed power system with a well-characterized current wave form and well understood electrical parameters. At Los Alamos, the authors have developed a capacitively driven, inductive store pulsed power machine, Pegasus, which meets these needs. They have also developed an extensive suite of diagnostics which are capable of characterizing the performance of the system and of the imploding liners. Pegasus consists of a 4.3 MJ capacitor bank, with a capacitance of 850 {micro}f fired with a typical initial bank voltage of 90 kV or less. The bank resistance is about 0.5 m{Omega}, and bank plus power flow channel has a total inductance of about 24 nH. In this paper the authors consider the theory and modeling of the first precision solid liner driver fielded on the LANL Pegasus pulsed power facility.

  4. Membrane behavior of clay liner materials

    NASA Astrophysics Data System (ADS)

    Kang, Jong Beom

    Membrane behavior represents the ability of porous media to restrict the migration of solutes, leading to the existence of chemico-osmosis, or the flow of liquid in response to a chemical concentration gradient. Membrane behavior is an important consideration with respect to clay soils with small pores and interactive electric diffuse double layers associated with individual particles, such as bentonite. The results of recent studies indicate the existence of membrane behavior in bentonite-based hydraulic barriers used in waste containment applications. Thus, measurement of the existence and magnitude of membrane behavior in such clay soils is becoming increasingly important. Accordingly, this research focused on evaluating the existence and magnitude of membrane behavior for three clay-based materials that typically are considered for use as liners for waste containment applications, such as landfills. The three clay-based liner materials included a commercially available geosynthetic clay liner (GCL) consisting of sodium bentonite sandwiched between two geotextiles, a compacted natural clay known locally as Nelson Farm Clay, and compacted NFC amended with 5% (dry wt.) of a sodium bentonite. The study also included the development and evaluation of a new flexible-wall cell for clay membrane testing that was used subsequently to measure the membrane behaviors of the three clay liner materials. The consolidation behavior of the GCL under isotropic states of stress also was evaluated as a preliminary step in the determination of the membrane behavior of the GCL under different effective consolidation stresses.

  5. Conversion of acoustic energy by lossless liners

    NASA Technical Reports Server (NTRS)

    Moehring, W.; Eversman, W.

    1982-01-01

    The Blokhintzev acoustic energy equation is applied to a two-dimensional duct containing a uniform flow with a finite length lining. It is shown that the difference of the incident and outgoing acoustic energy differs in general from the energy dissipated in the liner, the difference being related to the displacements at the liner's edges. It is shown that in the case of a locally reacting lossless liner for frequencies below the first cut-off frequency and for low Mach number acoustic energy is generated if the flow and the incident sound wave are in the same direction and is absorbed if these two directions are opposite unless special edge conditions are met. Furthermore it is shown under the same conditions that the ratio of the reflection coefficient at finite flow velocity to the reflection coefficient at vanishing velocity is to first order in Mach number independent of the liner characteristics. A numerical calculation confirms these predictions at least for mass-like linear admittance.

  6. Welded polypropylene liners for large descaling tanks

    NASA Technical Reports Server (NTRS)

    Abel, H. P.

    1971-01-01

    Liners for nitric and hydrofluoric acid tanks show no sign of deterioration after 18 months of continuous use. Each side of each edge of the polypropylene sheets is chamfered, and sheets are welded from both sides with polypropylene filler rod and a special hot-air welding torch.

  7. GRCop-84 Development for Combustion Chamber Liners

    NASA Technical Reports Server (NTRS)

    Ellis, David; Nathal, Michael; Yun, Hee Man; Lerch, Bradley; Greenbauer-Seng, Leslie; Thomas-Ogbuji, Linus; Holmes, Richard

    2000-01-01

    The development, test, and thermophysical & mechanical properties of a GRCop-84 alloy for combustion chamber liners is discussed. Topics discussed include: History of GRCop-84 development, GRCop-84 thermal expansion, thermal conductivity of GRCop-84, yield strength of GRCop-84, GRCop-84 creep lives, GrCop-84 low cycle fatigue (LCF) lives, and hot fire testing of GRCop-84 spool pieces.

  8. Diagnostics for the Plasma Liner Experiment

    SciTech Connect

    Lynn, A. G.; Merritt, E.; Gilmore, M.; Hsu, S. C.; Witherspoon, F. D.; Cassibry, J. T.

    2010-10-15

    The goal of the Plasma Liner Experiment (PLX) is to explore and demonstrate the feasibility of forming imploding spherical ''plasma liners'' via merging high Mach number plasma jets to reach peak liner pressures of {approx}0.1 Mbar using {approx}1.5 MJ of initial stored energy. Such a system would provide HED plasmas for a variety of fundamental HEDLP, laboratory astrophysics, and materials science studies, as well as a platform for experimental validation of rad-hydro and rad-MHD simulations. It could also prove attractive as a potential standoff driver for magnetoinertial fusion. Predicted parameters from jet formation to liner stagnation cover a large range of plasma density and temperature, varying from n{sub i}{approx}10{sup 16} cm{sup -3}, T{sub e}{approx_equal}T{sub i}{approx}1 eV at the plasma gun mouth to n{sub i}>10{sup 19} cm{sup -3}, T{sub e}{approx_equal}T{sub i}{approx}0.5 keV at stagnation. This presents a challenging problem for the plasma diagnostics suite which will be discussed.

  9. A liner timeline at Grand Central Sanitation

    SciTech Connect

    Woods, R.

    1994-08-01

    Since the promulgation of the minimum landfill liner requirements under RCRA's Subtitle D in September 1991, nearly every operating landfill in the US that has expanded horizontally has been brought up to speed with basic environmental protection measures, i.e., liners, leachate collection groundwater monitoring, etc. For most landfills, however, these changes did not happen overnight. For more than a decade, most of the states and countless private landfills have been anticipating the advent of Subtitle D and have been upgrading outdated landfills long before the federal regulations were enforced. Grand Central Sanitation, Inc. (GCS, Pen Argyl, Pa.), for example, is a case in point. The family-run company's sanitary landfill began operation as a 52-acre, natural renovation, or earthen barrier, fill in the early 1950s and its first two fill areas, now closed, had only natural soils as a liner. Today, GCS's facility has more than doubled its permitted capacity. Its 10th disposal cell, now under construction, is triple-lined with the latest synthetic geomembranes, including high-density polyethylene (HDPE) liners, geotextiles, geonets, and leachate collection systems.

  10. Statistically Based Approach to Broadband Liner Design and Assessment

    NASA Technical Reports Server (NTRS)

    Nark, Douglas M. (Inventor); Jones, Michael G. (Inventor)

    2016-01-01

    A broadband liner design optimization includes utilizing in-duct attenuation predictions with a statistical fan source model to obtain optimum impedance spectra over a number of flow conditions for one or more liner locations in a bypass duct. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners having impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increasing weighting to specific frequencies and/or operating conditions. One or more broadband design approaches are utilized to produce a broadband liner that targets a full range of frequencies and operating conditions.

  11. Heavy metals and human spermatozoa. III. The toxicity of copper ions for spermatozoa.

    PubMed

    Holland, M K; White, I G

    1988-12-01

    The dissolution of copper ions from copper metal into a saline medium in vitro was quantified using a colourimetric assay. The presence of spermatozoa enhanced this dissolution and increasing the protein content of the medium further increased the rate of dissolution. Approximately 17% of the copper released was either tightly bound to the spermatozoa or was within the cell and could not be removed by repeated washing. Once spermatozoa were immobilized, they could not be revived by washing and repeated changes of medium, by addition of copper specific-chelating agent or by extensive dialysis. When the toxicity to spermatozoa of cuprous and cupric ions was compared with copper metal, it could be shown that the quantity of cupric ions required (0.2-0.4 mg/ml) was in excess of the total quantity of copper released into solution. The quantity of cuprous ion required (0.08-0.16 mg/ml) to exert similar toxic effects to copper, was within the range of copper released from the metal. Under the conditions of this study, it is possible that cuprous ion would be oxidised to the cupric form generating free radicals in the process. It is not known whether the toxic effect is due to the cuprous ion, per se, or to radicals generated in its oxidation. Increasing the protein content of the medium to levels similar to low (8 mg/ml) and high (64 mg/ml) values reported in human uterine fluid increased the dissolution rate of copper but also offered some protection against the toxic effects of copper metal and cuprous and cupric ions.

  12. Understanding the microcrystal tests of three related phenethylamines: the ortho-metallated (±)-amphetamine formed with gold(III) chloride, and the tetrachloridoaurate(III) salts of (+)-methamphetamine and (±)-ephedrine.

    PubMed

    Wood, Matthew R; Lalancette, Roger A

    2013-04-01

    The ortho-metallation product of the reaction of (±)-amphetamine with gold(III) chloride, [D,L-2-(2-aminopropyl)phenyl-κ(2)N,C(1)]dichloridogold(III), [Au(C9H12N)Cl2], and the two salts resulting from crystallization of (+)-methamphetamine with gold(III) chloride, D-methyl(1-phenylpropan-2-yl)azanium tetrachloridoaurate(III), (C10H16N)[AuCl4], and of (±)-ephedrine with gold(III) chloride, D,L-(1-hydroxy-1-phenylpropan-2-yl)(methyl)azanium tetrachloridoaurate(III), (C10H16NO)[AuCl4], have different structures. The first makes a bidentate complex directly with a dichloridogold(III) group, forming a six-membered ring structure; the second and third each form a salt with [AuCl4](-) (each has two formula units in the asymmetric unit). The organic components are all members of the same class of stimulants that are prevalent in illicit drug use. These structures are important contributions to the understanding of the microcrystal tests for these drugs that have been employed for well over 100 years.

  13. Nanosheets of Two-Dimensional Magnetic and Conducting Fe(II)/Fe(III) Mixed-Valence Metal-Organic Frameworks.

    PubMed

    Benmansour, Samia; Abhervé, Alexandre; Gómez-Claramunt, Patricia; Vallés-García, Cristina; Gómez-García, Carlos J

    2017-08-09

    We report the synthesis, magnetic properties, electrical conductivity, and delamination into thin nanosheets of two anilato-based Fe(II)/Fe(III) mixed-valence two-dimensional metal-organic frameworks (MOFs). Compounds [(H3O)(H2O)(phenazine)3][Fe(II)Fe(III)(C6O4X2)3]·12H2O [X = Cl (1) and Br (2)] present a honeycomb layered structure with an eclipsed packing that generates hexagonal channels containing the water molecules. Both compounds show ferrimagnetic ordering at ca. 2 K coexisting with electrical conductivity (with room temperature conductivities of 0.03 and 0.003 S/cm). Changing the X group from Cl to Br leads to a decrease in the ordering temperature and room temperature conductivity that is correlated with the decrease of the electronegativity of X. Despite the ionic charge of the anilato-based layers, these MOFs can be easily delaminated in thin nanosheets with the thickness of a few monolayers.

  14. Influence of atomic processes on the implosion of plasma liners

    SciTech Connect

    Kim, Hyoungkeun; Zhang Lina; Samulyak, Roman; Parks, Paul

    2012-08-15

    The influence of atomic physics processes on the implosion of plasma liners for magneto-inertial nuclear fusion has been investigated numerically by using the method of front tracking in spherically symmetric geometry and equation of state models accounting for dissociation and ionization. Simulation studies of the self-collapse of argon liners to be used in the Los Alamos Plasma Liner Experiment (PLX) program have been performed as well as studies of implosion of deuterium and argon liners on plasma targets. Results show that atomic processes in converging liners reduce the temperature of liners and increase the Mach number that results in the increase of the stagnation pressure and the fusion energy gain. For deuterium and argon liners imploding on plasma targets, dissociation and ionization increased the stagnation pressure and the fusion energy gain by the factor of 1.5 (deuterium) and 2 (argon) correspondingly. Similarly, ionization during the self-collapse of argon liners leads to approximately doubling of the Mach number and the stagnation pressure. The influence of the longitudinal density spread of the liner has also been investigated. The self-collapse stagnation pressure decreased by the factor of 8.7 when the initial position of the liner was shifted from the merging radius (33 cm) to the PLX chamber edge (137.2 cm). Simulations with and without the heat conduction demonstrated that the heat conduction has negligible effect on the self-collapse pressure of argon liners.

  15. Geosynthetic clay liners shrinkage under simulated daily thermal cycles.

    PubMed

    Sarabadani, Hamid; Rayhani, Mohammad T

    2014-06-01

    Geosynthetic clay liners are used as part of composite liner systems in municipal solid waste landfills and other applications to restrict the escape of contaminants into the surrounding environment. This is attainable provided that the geosynthetic clay liner panels continuously cover the subsoil. Previous case histories, however, have shown that some geosynthetic clay liner panels are prone to significant shrinkage and separation when an overlying geomembrane is exposed to solar radiation. Experimental models were initiated to evaluate the potential shrinkage of different geosynthetic clay liner products placed over sand and clay subsoils, subjected to simulated daily thermal cycles (60°C for 8 hours and 22°C for 16 hours) modelling field conditions in which the liner is exposed to solar radiation. The variation of geosynthetic clay liner shrinkage was evaluated at specified times by a photogrammetry technique. The manufacturing techniques, the initial moisture content, and the aspect ratio (ratio of length to width) of the geosynthetic clay liner were found to considerably affect the shrinkage of geosynthetic clay liners. The particle size distribution of the subsoil and the associated suction at the geosynthetic clay liner-subsoil interface was also found to have significant effects on the shrinkage of the geosynthetic clay liner.

  16. Liner Stability Experiments at Pegasus: Diagnostics and Experimental Results

    SciTech Connect

    Clark, D.A.; Morgan, D.V.; Rodriguez, G.

    1998-10-18

    A series of experiments to compare imploding liner performance with magneto-hydrodynamic (MHD) modeling has been performed at the Los Alamos National Laboratory Pegasus II pulse power machine. Liner instability growth originating from initial perturbations machined into the liner has been observed with high resolution. Three major diagnostics were used: radiography, Velocity Interferometer for a Surface of Any Reflector (VISAR), and fiber optic impact pins. For radiography, three flash x-ray units were mounted radially to observe liner shape at three different times during the implosion. Liner velocity was measured continuously with the VISAR for the entire distance traveled in two experiments. Optical impact pins provide a high-resolution measure of liner symmetry and shape near the end of travel. Liner performance has compared well with predictions.

  17. First Stars. III. A detailed elemental abundance study of four extremely metal-poor giant stars

    NASA Astrophysics Data System (ADS)

    François, P.; Depagne, E.; Hill, V.; Spite, M.; Spite, F.; Plez, B.; Beers, T. C.; Barbuy, B.; Cayrel, R.; Andersen, J.; Bonifacio, P.; Molaro, P.; Nordström, B.; Primas, F.

    2003-06-01

    This paper reports detailed abundance analyses for four extremely metal-poor (XMP) giant stars with [Fe/H]<-3.8, based on high-resolution, high-S/N spectra from the ESO VLT (Kueyen/UVES) and LTE model atmosphere calculations. The derived [alpha /Fe] ratios in our sample exhibit a small dispersion, confirming previous findings in the literature, i.e. a constant overabundance of the alpha -elements with a very small (if any) dependence on [Fe/H]. In particular, the very small scatter we determine for [Si/Fe] suggests that this element shows a constant overabundance at very low metallicity, a conclusion which could not have been derived from the widely scattered [Si/Fe] values reported in the literature for less metal-poor stars. For the iron-peak elements, our precise abundances for the four XMP stars in our sample confirm the decreasing trend of Cr and Mn with decreasing [Fe/H], as well as the increasing trend for Co and the absence of any trend for Sc and Ni. In contrast to the significant spread of the ratios [Sr/Fe] and [Ba/Fe], we find [Sr/Ba] in our sample to be roughly solar, with a much lower dispersion than previously found for stars in the range -3.5 < [Fe/H] < -2.5. Based on observations made with the ESO Very Large Telescope at Paranal Observatory, Chile (Large Programme ID 165.N-0276(A)). The complete version of Table 5 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or via http:/ /cdsweb.u-strasbg.fr/cgi-bin/qcat?J /A+A/403/1105

  18. Protection of open-metal V(III) sites and their associated CO₂/CH₄/N₂/O₂/H₂O adsorption properties in mesoporous V-MOFs.

    PubMed

    Yang, Jiangfeng; Wang, Yong; Li, Libo; Zhang, Zhuoming; Li, Jinping

    2015-10-15

    Metal-organic frameworks with open metal site are potential sorbents for the separation of gas mixtures; however, low valence metal will bind to oxygen in the open air causing a decrease in adsorption ability. We now report open-metal sites V(III) on both MIL-100V(III/IV) and MIL-101V(III/IV) that can be protected with water molecules, and which associated CO2/CH4/N2/O2 adsorption properties on these two mesoporous V-MOFs were investigated. The protective properties of water were investigated and evaluated using density functional theory simulations. The binding energy of single O2 on open-metal V(III) site was 93.278 kJ/mol, which decreased to 26.5 kJ/mol when H2O occupies the site. When the water coating is removed, the X-ray photoelectron spectroscopy pattern of V2p showed that the V-MOF changes to MIL-100V(IV) and MIL-101V(IV) at 298 K because of the action of O2. Under these conditions, O2 binds strongly on the open V site significantly reducing the BET (Brunauer-Emmett-Teller) surface and CH4 adsorption volume of the V-MOFs. From the ideal adsorbed solution theory calculated, the adsorption selectivity of CH4/N2 is higher before than after binding of O2 (with V(III) site). In contrast, the adsorption selectivity of CO2/CH4 is higher after than before O2 binding (with no more V(III) sites). Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Helical Striation Pattern Generation and Axial Field Compression in Aluminum Liner Experiments at 1 MA

    NASA Astrophysics Data System (ADS)

    Atoyan, Levon; Byvank, Tom; Greenly, John; Kusse, Bruce; Pikuz, Sergei; Potter, William; Shelkovenko, Tania; Hammer, David

    2015-11-01

    Awe et al. [Phys. Plasmas 21, 235005, 2014] found on the 20 MA Z machine that applying an externally generated axial magnetic field to an imploding liner produces a helical plasma pattern near the surface of the liner. Here we show that this phenomenon is also observed using 10 mm long cylindrical metal liners having 16 mm diameter and 3 to 6 μm wall thickness on the 1 MA, 100-200 ns COBRA pulsed power generator [T. A. Shelkovenko et al., Rev. Sci. Instrum. 77, 10F521, 2006]. The magnetic field in these experiments is created using a 150 μs rise time Helmholtz coil, and the pattern is observed using extreme ultraviolet imaging. Moreover, using B-dot probes we show that there is a 4-8% axial magnetic field compression relative to the initially applied Bz. Using a visible light framing camera, we show that this compression begins before the outside surface of the liner has become a visible light emitting plasma. This research was sponsored by the NNSA SSAP under DOE Coop Agreement DE-NA0001836 and DOE grant DE-NA0001847 as well as by NSF grant PHY-1102471.

  20. Friction Stir Welding of GR-Cop 84 for Combustion Chamber Liners

    NASA Technical Reports Server (NTRS)

    Russell, Carolyn K.; Carter, Robert; Ellis, David L.; Goudy, Richard

    2004-01-01

    GRCop-84 is a copper-chromium-niobium alloy developed by the Glenn Research Center for liquid rocket engine combustion chamber liners. GRCop-84 exhibits superior properties over conventional copper-base alloys in a liquid hydrogen-oxygen operating environment. The Next Generation Launch Technology program has funded a program to demonstrate scale-up production capabilities of GR-Cop 84 to levels suitable for main combustion chamber production for the prototype rocket engine. This paper describes a novel method of manufacturing the main combustion chamber liner. The process consists of several steps: extrude the GR-Cop 84 powder into billets, roll the billets into plates, bump form the plates into cylinder halves and friction stir weld the halves into a cylinder. The cylinder is then metal spun formed to near net liner dimensions followed by finish machining to the final configuration. This paper describes the friction stir weld process development including tooling and non-destructive inspection techniques, culminating in the successful production of a liner preform completed through spin forming.

  1. Surface chemistry of the atomic layer deposition of metals and group III oxides

    NASA Astrophysics Data System (ADS)

    Goldstein, David Nathan

    Atomic Layer Deposition (ALD) is a thin-film growth technique offering precise control of film thickness and the ability to coat high-aspect-ratio features such as trenches and nanopowders. Unlike other film growth techniques, ALD does not require harsh processing conditions and is not limited by line-of-sight deposition. Emerging applications for ALD materials include semiconductor devices, gas sensors, and water-diffusion barriers. The chemistry behind ALD involves understanding how the precursors interact with surfaces to deposit the desired material. All ALD precursors need to be stable on the substrate to ensure self-limiting behavior yet reactive enough to be easily removed with the second reagent. Recent precursor development has provided many volatile organometallic compounds for most of the periodic table. As the number of precursors increases, proper precursor choice becomes crucial. This is because the film properties, growth rates, and growth temperature vary widely between the precursors. Many of the above traits can be predicted with knowledge of the precursor reaction mechanisms. This thesis aims to link surface reaction mechanisms to observed growth and nucleation trends in metal and oxide ALD systems. The first portion of this thesis explores the mechanisms of two ALD oxide systems. First, I examine the mechanism of ALD alumina with ozone. Ozone is used as an oxidant in the semiconductor industry because the deposited Al 2O3 films possess better insulating properties and ozone is easier to purge from a vacuum system. FT-IR analysis reveals a complicated array of surface intermediates such as formate, carbonate, and methoxy groups that form during Al2O3 growth with ozone. Next, a new method to deposit thin films of Ga2O3 is introduced. Gallium oxide is a transparent conducting oxide that needs expensive solid precursors to be deposited by ALD. I show that trimethylgallium is a good high-temperature ALD precursor that deposits films of Ga2O 3 with

  2. Minuteman Stage III Operational Surveillance Program Seven-Year Testing Bondline Aging Study,

    DTIC Science & Technology

    1985-12-01

    Liner Gel Fraction at Various Motor Locations ......... . . 25 14 Liner Moisture at Various Motor Locations ............. ... 26 6 15 Motor TC 30005 ...PageI ,,. 18 Shore A Hardness Gradient of ANB-3066 Propellant at the Forward Equator ........ ...................... .. 30 19 Motor TC 30005 ...75 I 2 Matrix for Minuteman Stage III Bondline Aging Program ........ 76 3 Motor TC 30005 Material Properties Data, Forward

  3. An investigation of cadmium selenide photoluminescence as a chemical sensing method for group V hydrides and group III metal trialkyls

    NASA Astrophysics Data System (ADS)

    Winder, Edmund Jacques

    1997-10-01

    Chapter 1: Introduction. The origin of photoluminescence in semiconductors and the possible use of photoluminescence (PL) as a chemical sensing method are discussed. The process of adsorption and the CdSe surface are described. Chapter 2: Group V hydrides. The binding of three Group V hydrides (ammonia, phosphine, and arsine) to an etched CdSe surface is explored. They all act as Lewis bases toward the surface, producing reversible concentration-dependent PL enhancements. The PL changes are too slow for practical applications, but a moderate temperature increase was shown to substantially increase the analyte adsorption and desorption rates. A compact "hybrid" sensor device was constructed. Chapter 3: Group III trialkyls. The binding of four Group III metal trialkyls, trimethyl aluminum (TMAl), trimethyl gallium (TMGa), triethyl gallium (TEGa), and trimethyl indium (TMIn), to an etched CdSe surface is investigated. They all produce large and irreversible PL enhancements. This irreversibility is countered with three approaches. First, the use of sulfur-containing coatings can produce a CdSe surface which yields reversible PL enhancements when exposed to the trialkyls. Second, exposing an etched CdSe surface to amines subsequent to metal trialkyl exposure temporarily suppresses the large PL enhancement caused by the trialkyl; this is likely due to the amines forming neutral adducts with the trialkyls. Studies with a family of amines indicate the degree of suppression provided by an amine is dependent on steric factors. Third, pre-formed adducts of metal trialkyls with trimethylamine show reversible binding to etched CdSe. Chapter 4: Thermoelectric devices. Thermoelectric devices can be used as heat engines to generate electricity from a temperature difference or as heat pumps to transport heat when supplied with electricity. Because they are solid-state devices, they are compact, quiet, and rugged. Currently limited to niche applications due to their relatively low

  4. ALFALFA DISCOVERY OF THE NEARBY GAS-RICH DWARF GALAXY LEO P. III. AN EXTREMELY METAL DEFICIENT GALAXY

    SciTech Connect

    Skillman, Evan D.; Berg, Danielle A.; Olive, Keith A.; McQuinn, Kristen B. W. E-mail: berg@astro.umn.edu E-mail: kmcquinn@astro.umn.edu; and others

    2013-07-01

    We present KPNO 4 m and LBT/MODS spectroscopic observations of an H II region in the nearby dwarf irregular galaxy Leo P discovered recently in the Arecibo ALFALFA survey. In both observations, we are able to accurately measure the temperature sensitive [O III] {lambda}4363 line and determine a ''direct'' oxygen abundance of 12 + log(O/H) = 7.17 {+-} 0.04. Thus, Leo P is an extremely metal deficient (XMD) galaxy, and, indeed, one of the most metal deficient star-forming galaxies ever observed. For its estimated luminosity, Leo P is consistent with the relationship between luminosity and oxygen abundance seen in nearby dwarf galaxies. Leo P shows normal {alpha} element abundance ratios (Ne/O, S/O, and Ar/O) when compared to other XMD galaxies, but elevated N/O, consistent with the ''delayed release'' hypothesis for N/O abundances. We derive a helium mass fraction of 0.2509{sup +0.0184}{sub -0.0123}, which compares well with the WMAP + BBN prediction of 0.2483 {+-} 0.0002 for the primordial helium abundance. We suggest that surveys of very low mass galaxies compete well with emission line galaxy surveys for finding XMD galaxies. It is possible that XMD galaxies may be divided into two classes: the relatively rare XMD emission line galaxies which are associated with starbursts triggered by infall of low-metallicity gas and the more common, relatively quiescent XMD galaxies like Leo P, with very low chemical abundances due to their intrinsically small masses.

  5. Homoleptic rare-earth metal(III) tetramethylaluminates: structural chemistry, reactivity, and performance in isoprene polymerization.

    PubMed

    Zimmermann, Melanie; Frøystein, Nils Age; Fischbach, Andreas; Sirsch, Peter; Dietrich, H Martin; Törnroos, Karl W; Herdtweck, Eberhardt; Anwander, Reiner

    2007-01-01

    The complexes [Ln(AlMe4)3] (Ln=Y, La, Ce, Pr, Nd, Sm, Ho, Lu) have been synthesized by an amide elimination route and the structures of [Lu{(micro-Me)2AlMe2}3], [Sm{(micro-Me)2AlMe2}3], [Pr{(micro-Me)2AlMe2}3], and [La{(micro-Me)2AlMe2}2{(micro-Me)3AlMe}] determined by X-ray crystallography. These structures reveal a distinct Ln3+ cation size-dependency. A comprehensive insight into the intrinsic properties and solution coordination phenomena of [Ln(AlMe4)3] complexes has been gained from extended dynamic 1H and 13C NMR spectroscopic studies, as well as 1D 89Y, 2D 1H/89Y, and 27Al NMR spectroscopic investigations. [Ce(AlMe4)3] and [Pr(AlMe4)3] have been used as alkyl precursors for the synthesis of heterobimetallic alkylated rare-earth metal complexes. Both carboxylate and siloxide ligands can be introduced by methane elimination reactions that give the heterobimetallic complexes [Ln{(O2CAriPr)2(micro-AlMe2)}2(AlMe4)(C6H14)n] and [Ln{OSi(OtBu)3}(AlMe3)(AlMe4)2], respectively. [Pr{OSi(OtBu)3}(AlMe3)(AlMe4)2] has been characterized by X-ray structure analysis. All of the cerium and praseodymium complexes are used as precatalysts in the stereospecific polymerization of isoprene (1-3 equivalents of Et2AlCl as co-catalyst) and compared to the corresponding neodymium-based initiators reported previously. The superior catalytic performance of the homoleptic complexes leads to quantitative yields of high-cis-1,4-polyisoprene (>98%) in almost all of the polymerization experiments. In the case of the binary catalyst mixtures derived from carboxylate or siloxide precatalysts quantitative formation of polyisoprene is only observed for nLn:nCl=1:2. The influence of the metal size is illustrated for the heterobimetallic lanthanum, cerium, praseodymium, neodymium, and gadolinium carboxylate complexes, and the highest activities are observed for praseodymium as a metal center in the presence of one equivalent of Et2AlCl.

  6. Dissimilatory reduction of FeIII (EDTA) with microorganisms in the system of nitric oxide removal from the flue gas by metal chelate absorption.

    PubMed

    Ma, Bi-yao; Li, Wei; Jing, Guo-hua; Shi, Yao

    2004-01-01

    In the system of nitric oxide removal from the flue gas by metal chelate absorption, it is an obstacle that ferrous absorbents are easily oxidized by oxygen in the flue gas to ferric counterparts, which are not capable of binding NO. By adding iron metal or electrochemical method, FeIII(EDTA) can be reduced to FeII(EDTA). However, there are various drawbacks associated with these techniques. The dissimilatory reduction of FeIII(EDTA) with microorganisms in the system of nitric oxide removal by metal chelate absorption was investigated. Ammonium salt instead of nitrate was used as the nitrogen source, as nitrates inhibited the reduction of FeIII due to the competition between the two electron acceptors. Supplemental glucose and lactate stimulated the formation of FeII more than ethanol as the carbon sources. The microorganisms cultured at 50 degrees C were not very sensitive to the other experimental temperature, the reduction percentage of FeIII varied little with the temperature range of 30-50 degrees C. Concentrated Na2CO3 solution was added to adjust the solution pH to an optimal pH range of 6-7. The overall results revealed that the dissimilatory ferric reducing microorganisms present in the mix-culture are probably neutrophilic, moderately thermophilic FeIII reducers.

  7. Acetabular screw head-induced ceramic acetabular liner fracture in cementless ceramic-on-ceramic total hip arthroplasty.

    PubMed

    Lee, Su Chan; Jung, Kwang Am; Nam, Chang Hyun; Kim, Tea Ho; Ahn, Nong Kyoum; Hwang, Seung Hyun

    2010-05-12

    Ceramic liner fractures are rare after ceramic-on-ceramic THA. This article describes a case of an early ceramic liner fracture caused by impingement with a tilted acetabular screw head 2 months after cementless ceramic-on-ceramic THA. A 59-year-old man underwent primary THA for avascular necrosis of his right femoral head. The implant used was an Osteonics Secur-Fit HA ceramic-on-ceramic bearing system. The metal shell was fixed with 1 cancellous bone screw. During the index procedure, the acetabular screw seemed tilted in the metal shell hole, but the liner was fully seated in the metal shell without difficulty. However, 2 months later he re-presented due to pain and crepitation in the right hip. Radiographs showed that the ceramic acetabular insert had fractured. At revision, ceramic insert had fractured into large and numerous comminuted fragments, and the acetabular screw head was slightly tilted and protruded over the inner surface of the metal shell, which had worn eccentrically. The ceramic inner head and metal shell were visibly intact. Because the metal shell-bone fixation was firm, a new identical design ceramic liner and head were fitted, and no adverse event has occurred since. This case suggests that a complete check of the inside of the shell should be made when using an acetabular screw and ceramic liner. In particular, the screw head must not be tilted or left proud of the inside surface of the shell. Correct acetabular screw direction and seating are essential to avoid detrimental clinical consequences. Copyright 2010, SLACK Incorporated.

  8. Abundance analyses of metal-poor stars. III - Red spectra of nine dwarfs

    NASA Astrophysics Data System (ADS)

    Peterson, R. C.

    1980-01-01

    Logarithmic iron abundances with respect to the sun are presented for nine cool, metal-poor dwarfs, and rederived for 15 hotter dwarfs and subgiants. Equivalent widths of lines as weak as 10 mA are used in this analysis, by invoking the goodness of the wavelength coincidence between observed and theoretical line positions to discriminate against noise features and line blends. For the stars discussed by Peterson (1978), the use of furnace gf-values and an independently determined value (-4.50) for the logarithm of the solar iron-to-hydrogen ratio produces abundances which are lower by 0.2 dex than those derived from a solar/stellar line-by-line comparison with vt = 1 km/sec.

  9. III-nitride quantum cascade detector grown by metal organic chemical vapor deposition

    SciTech Connect

    Song, Yu Huang, Tzu-Yung; Badami, Pranav; Gmachl, Claire; Bhat, Rajaram; Zah, Chung-En

    2014-11-03

    Quantum cascade (QC) detectors in the GaN/Al{sub x}Ga{sub 1−x}N material system grown by metal organic chemical vapor deposition are designed, fabricated, and characterized. Only two material compositions, i.e., GaN as wells and Al{sub 0.5}Ga{sub 0.5}N as barriers are used in the active layers. The QC detectors operates around 4 μm, with a peak responsivity of up to ∼100 μA/W and a detectivity of up to 10{sup 8} Jones at the background limited infrared performance temperature around 140 K.

  10. An extreme O III emitter at z=3.2: a low metallicity Lyman continuum source

    NASA Astrophysics Data System (ADS)

    de Barros, S.; Vanzella, E.

    2015-12-01

    We investigate the physical properties of a Lyman continuum emitter candidate at z=3.212 with photometric coverage from U to MIPS 24μm band and VIMOS/VLT and MOSFIRE/Keck spectroscopy. Investigation of the UV spectrum confirms a direct spectroscopic detection of the Lyman continuum emission with S/N>5. Non-zero Lyα flux at the systemic redshift and high Lyman-α escape fraction suggest a low HI column density. The weak C and Si low-ionization absorption lines are also consistent with a low covering fraction along the line of sight. The O IIIdoub+Hβ equivalent width is one of the largest reported for a galaxy at z>3 (EW(O IIIdoub+Hβ)} ≃q 1600Å, rest-frame; 6700Å observed-frame) and the NIR spectrum shows that this is mainly due to an extremely strong [OIII] emission. The large observed O III/O II ratio (>10) and high ionization parameter are consistent with prediction from photoionization models in case of a density-bounded nebula scenario. This source is currently the first high-z example of a Lyman continuum emitter exhibiting indirect and direct evidences of a Lyman continuum leakage and having physical properties consistent with theoretical expectation from Lyman continuum emission from a density-bounded nebula.

  11. Broadband Liner Optimization for the Source Diagnostic Test Fan

    NASA Technical Reports Server (NTRS)

    Nark, Douglas M.; Jones, Michael G.

    2012-01-01

    The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more appealing. This paper describes a broadband acoustic liner optimization study for the scale model Source Diagnostic Test fan. Specifically, in-duct attenuation predictions with a statistical fan source model are used to obtain optimum impedance spectra over a number of flow conditions for three liner locations in the bypass duct. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Typical tonal liner designs targeting single frequencies at one operating condition are first produced to provide baseline performance information. These are followed by multiple broadband design approaches culminating in a broadband liner targeting the full range of frequencies and operating conditions. The broadband liner is found to satisfy the optimum impedance objectives much better than the tonal liner designs. In addition, the broadband liner is found to provide better attenuation than the tonal designs over the full range of frequencies and operating conditions considered. Thus, the current study successfully establishes a process for the initial design and evaluation of novel broadband liner concepts for complex engine configurations.

  12. Kiloparsec-scale radio emission in Seyfert and LINER galaxies

    NASA Astrophysics Data System (ADS)

    Singh, Veeresh; Ishwara-Chandra, C. H.; Wadadekar, Yogesh; Beelen, Alexandre; Kharb, Preeti

    2015-01-01

    Seyfert and LINER galaxies are known to exhibit compact radio emission on ˜10-100 pc scales, but larger Kiloparsec-Scale Radio structures (KSRs) often remain undetected in sub-arcsec high-resolution observations. We investigate the prevalence and nature of KSRs in Seyfert and LINER galaxies using the 1.4 GHz VLA FIRST and NVSS observations. Our sample consists of 2651 sources detected in FIRST and of these 1737 sources also have NVSS counterparts. Considering the ratio of total to peak flux density (θ = (Sint/Speak)1/2) as a parameter to infer the presence of extended radio emission we show that ≥30 per cent of FIRST-detected sources possess extended radio structures on scales larger than 1.0 kpc. The use of low-resolution NVSS observations help us to recover faint extended KSRs that are resolved out in FIRST observations and results in ≥42.5 per cent KSR sources in FIRST-NVSS sub-sample. This fraction is only a lower limit owing to the combination of projection, resolution and sensitivity effects. Our study demonstrates that KSRs may be more common than previously thought and are found across all redshifts, luminosities and radio loudness. The extranuclear radio luminosity of KSR sources is found to be positively correlated with the core radio luminosity as well as the [O III] λ5007 Å line luminosity and this can be interpreted as KSRs being powered by AGN rather than star formation. The distributions of the FIR-to-radio ratios and mid-IR colours of KSR sources are also consistent with their AGN origin. However, contribution from star formation cannot be ruled out particularly in sources with low radio luminosities.

  13. Proteomic analysis in Daphnia magna exposed to As(III), As(V) and Cd heavy metals and their binary mixtures for screening potential biomarkers.

    PubMed

    Le, Thai-Hoang; Lim, Eun-Suk; Hong, Nam-Hui; Lee, Sung-Kyu; Shim, Yon Sik; Hwang, Jin Rae; Kim, Yang-Hoon; Min, Jiho

    2013-11-01

    In this study, the effects of three widespread heavy metals, As(III), As(V) and Cd, and their binary mixtures on the proteomic profile in D. magna were examined to screen novel protein biomarkers using the two-dimensional gel electrophoresis method (2DE). Ten 20d daphnia were exposed to the LC20 concentrations for each of a total of 8 treatments, including the control, As(III), As(V), Cd, [As(III)+As(V)], [As(III)+Cd], [As(V)+Cd], and [As(III), As(V), Cd], for 24h before protein isolation. Three replicates were performed for each treatment. These protein samples were employed for 2DE experiments with a pH gradient gel strip from pH 3 to pH 10. The protein spots were detected by a silver staining process and their intensities were analyzed by Progenesis software to discover the differentially expressed proteins (DEPs) in response to each heavy metal. A total of 117 differentially expressed proteins (DEPs) were found in daphnia responding to the 8 treatments and mapped onto a 2D proteome map, which provides some information of the molecular weight (MW) and pI value for each protein. All of these DEPs are considered as potential candidates for protein biomarkers in D. magna for detecting heavy metals in the aquatic ecosystem. Comparing the proteomic results among these treatments suggested that exposing D. magna to binary mixtures of heavy metals may result in some complex interactive molecular responses within them, rather than just the simple sum of the proteomic profiles of the individual chemicals, (As(III), As(V), and Cd).

  14. Effect of denture cleansers on surface hardness of resilient denture liners at various time intervals- an in vitro study.

    PubMed

    Pahuja, Rasleen Kaur; Garg, Sandeep; Bansal, Sanjay; Dang, Rajat Harvinder

    2013-08-01

    This study was aimed to determine the effect of two chemically distinct denture cleansers and water on the surface hardness of acrylic and silicone based soft denture liners at various time intervals. Two commonly used commercial resilient liner material were selected based on their chemical composition (silicone- and acrylic-based soft liners) for this investigation. 120 cylindrical specimens were made of 15 mm × 10 mm dimensions (according to ASTM: D-2240-64T) in a custom made metal mold. All specimens were stored in artificial saliva throughout the study. Forty specimens were cleansed daily in 0.5% sodium hypochlorite solution; forty were cleansed in sodium perborate and remaining forty specimens were daily rinsed in water. Testing was done at 1 week, 1 month, 3 months and 6 months for surface hardness using a Shore A Durometer. A mean of 3 reading for each sample was subjected to one-way ANOVA, Post Hoc test and pair-t test for statistical analysis. P values of less than 0.05 were taken as statistically significant. Surface hardness of all the samples was significantly higher after a period of 6 months irrespective of the cleansing treatment. Minor changes were observed between control, sodium hypochlorite and sodium perborate groups with time. Greater change was observed in surface hardness of acrylic-based soft denture liners as compared to silicone-based soft liners for all groups, as time progressed. Silicone-based soft denture liners performed significantly better in all cleansing treatments than acrylic-based soft denture liners.

  15. Effect of denture cleansers on surface hardness of resilient denture liners at various time intervals- an in vitro study

    PubMed Central

    Pahuja, Rasleen Kaur; Bansal, Sanjay

    2013-01-01

    PURPOSE This study was aimed to determine the effect of two chemically distinct denture cleansers and water on the surface hardness of acrylic and silicone based soft denture liners at various time intervals. MATERIALS AND METHODS Two commonly used commercial resilient liner material were selected based on their chemical composition (silicone- and acrylic-based soft liners) for this investigation. 120 cylindrical specimens were made of 15 mm × 10 mm dimensions (according to ASTM: D-2240-64T) in a custom made metal mold. All specimens were stored in artificial saliva throughout the study. Forty specimens were cleansed daily in 0.5% sodium hypochlorite solution; forty were cleansed in sodium perborate and remaining forty specimens were daily rinsed in water. Testing was done at 1 week, 1 month, 3 months and 6 months for surface hardness using a Shore A Durometer. A mean of 3 reading for each sample was subjected to one-way ANOVA, Post Hoc test and pair-t test for statistical analysis. P values of less than 0.05 were taken as statistically significant. RESULTS Surface hardness of all the samples was significantly higher after a period of 6 months irrespective of the cleansing treatment. Minor changes were observed between control, sodium hypochlorite and sodium perborate groups with time. Greater change was observed in surface hardness of acrylic-based soft denture liners as compared to silicone-based soft liners for all groups, as time progressed. CONCLUSION Silicone-based soft denture liners performed significantly better in all cleansing treatments than acrylic-based soft denture liners. PMID:24049568

  16. Electrochemical detection of arsenic(III) completely free from noble metal: Fe3O4 microspheres-room temperature ionic liquid composite showing better performance than gold.

    PubMed

    Gao, Chao; Yu, Xin-Yao; Xiong, Shi-Quan; Liu, Jin-Huai; Huang, Xing-Jiu

    2013-03-05

    In recent decades, electrochemical detection of arsenic(III) has been undergoing revolutionary developments with higher sensitivity and lower detection limit. Despite great success, electrochemical detection of As(III) still depends heavily on noble metals (predominantly Au) in a strong acid condition, thus increasing the cost and hampering the widespread application. Here, we report a disposable platform completely free from noble metals for electrochemical detection of As(III) in drinking water under nearly neutral condition by square wave anodic stripping voltammetry. By combining the high adsorptivity of Fe3O4 microspheres toward As(III) and the advantages of room temperature ionic liquid (RTIL), the Fe3O4-RTIL composite modified screen-printed carbon electrode (SPCE) showed even better electrochemical performance than commonly used noble metals. Several ionic liquids with different viscosities and surface tensions were found to have a different effect on the voltammetric behavior toward As(III). Under the optimized conditions, the Fe3O4-RTIL composites offered direct detection of As(III) within the desirable range (10 ppb) in drinking water as specified by the World Health Organization (WHO), with a detection limit (3σ method) of 8 × 10(-4) ppb. The obtained sensitivity was 4.91 μA ppb(-1), which is the highest as far as we know. In addition, a possible mechanism for As(III) preconcentration based on adsorption has been proposed and supported by designed experiments. Finally, this platform was successfully applied to analyzing a real sample collected from Inner Mongolia, China.

  17. Correlating shaped charge performance with processing conditions and microstructure of an aluminum alloy 1100 liner enabled by a new method to arrest nascent jet formation

    NASA Astrophysics Data System (ADS)

    Scheid, James Eric

    Aluminum-lined shaped charges are used in special applications where jet and / or slug residue in the target is undesired. The three different microstructures of the aluminum liners studied herein resulted from three different manufacturing interpretations of the same design. One interpretation was completely machining the liners from best available annealed round stock. The second was to cold-forge the liners from annealed round-stock in an open-die forge to near-final dimensions, and then machine the liners to the final dimensions. The third variant in this study was to use the above forged liner, but with annealing after the machining. These three manufacturing choices resulted in significant variations in shaped charge performance. The goal of this research was to clarify the relationships between the liner metal microstructure and properties, and the corresponding shaped charge dynamic flow behavior. What began as an investigation into user-reported performance problems associated inherently with liner manufacturing processes and resultant microstructure, resolved into new understandings of the relationships between aluminum liner microstructure and shaped charge collapse kinetics. This understanding was achieved through an extensive literature review and the comprehensive characterization of the material properties of three variants of an 1100 aluminum shaped charge liner with a focus on collapse and nascent jet formation. The machined liner had a microstructure with large millimeter-sized grains and fine particles aligned in bands parallel to the charge axis. The forged liner microstructure consisted of very small one micrometer-sized (1 mum) subgrains and fine particles aligned largely in bands elongated parallel to the liner contour. The annealed liner was characterized by ten micrometer (10 mum) sized equiaxed grains with residual fine particles in the forged alignment. This characterization was enabled by the development, execution and validation of a

  18. The utilization of sepiolite in landfill liners.

    PubMed

    Güney, Y; Ozdemir, H V

    2005-05-01

    In this study, sepiolite and natural soil-added sepiolite mixtures were studied to find out whether they can be used as compacted landfill liner, as they are an economic alternative to the other compacted day liners or not. Geotechnical and physico-chemical properties of sepiolite and sepiolite mixtures, containing 25% and 50% natural soil by weight, and compacted at water contents ranging from 35% to 60%, were determined by hydraulic conductivity, leachate analysis, unconfined compression strength, consolidation, volumetric shrinkage and swelling tests. The test results showed that the compacted natural soil-added sepiolite mixtures exhibit lower permeability and swelling properties, and higher compressive strength than pure sepiolite. The overall evaluation of the results has revealed that the natural soil-added sepiolite showed good promise and it can be used as a landfill barrier due to its high capacity of contaminant adsorption.

  19. Real-space electron transfer in III-nitride metal-oxide-semiconductor-heterojunction structures

    NASA Astrophysics Data System (ADS)

    Saygi, S.; Koudymov, A.; Adivarahan, V.; Yang, J.; Simin, G.; Khan, M. Asif; Deng, J.; Gaska, R.; Shur, M. S.

    2005-07-01

    The real-space transfer effect in a SiO2/AlGaN /GaN metal-oxide-semiconductor heterostructure (MOSH) from the two-dimensional (2D) electron gas at the heterointerface to the oxide-semiconductor interface has been demonstrated and explained. The effect occurs at high positive gate bias and manifests itself as an additional step in the capacitance-voltage (C-V) characteristic. The real-space transfer effect limits the achievable maximum 2D electron gas density in the device channel. We show that in MOSH structures the maximum electron gas density exceeds up to two times that at the equilibrium (zero bias) condition. Correspondingly, a significant increase in the maximum channel current (up to two times compared to conventional Schottky-gate structures) can be achieved. The real-space charge transfer effect in MOSH structures also opens up a way to design novel devices such as variable capacitors, multistate switches, memory cells, etc.

  20. Marine molluscs in environmental monitoring. III. Trace metals and organic pollutants in animal tissue and sediments

    NASA Astrophysics Data System (ADS)

    Feldstein, Tamar; Kashman, Yoel; Abelson, Avigdor; Fishelson, Lev; Mokady, Ofer; Bresler, Vladimir; Erel, Yigal

    2003-10-01

    Concentrations of trace elements and organic pollutants were determined in marine sediments and molluscs from the Mediterranean and Red Sea coasts of Israel. Two bivalve species (Donax trunculus, Pteria aegyptia), two gastropod species (Patella caerulea, Cellana rota) and sediments were sampled at polluted and relatively clean, reference, sites. Along the Mediterranean coast of Israel, sediments and molluscs from Haifa Bay stations were enriched with both organic and trace element contaminants. In the Red Sea, differences between the polluted and reference sites were less pronounced. Bio-concentration factors indicate a significant concentration of Zn, As, Cd, Sn and Pb in animal tissue relative to the concentrations of these elements in the sediments. In contrast, Ce, La and U were not concentrated in molluscs. The trace element results indicate a saturation of the detoxification mechanisms in molluscs from polluted sites. The concentrations of organic pollutants at the same sites are at the lower range of values recorded in other studies. However, synergistic effects between these compounds and between them and metals can lead to acute toxicity.

  1. III-V-on-nothing metal-oxide-semiconductor field-effect transistors enabled by top-down nanowire release process: Experiment and simulation

    NASA Astrophysics Data System (ADS)

    Gu, J. J.; Koybasi, O.; Wu, Y. Q.; Ye, P. D.

    2011-09-01

    III-V-on-nothing (III-VON) metal-oxide-semiconductor field-effect transistors (MOSFETs) are experimentally demonstrated with In0.53Ga0.47As as channel and atomic layer deposited Al2O3 as gate dielectric. A hydrochloric acid based release process has been developed to create an air gap beneath the InGaAs channel layer, forming the nanowire channel with width down to 40 nm. III-VON MOSFETs with channel lengths down to 50 nm are fabricated and show promising improvement in drain-induced barrier lowering, due to suppressed short-channel effects. The top-down processing technique provides a viable pathway towards fully gate-all-around III-V MOSFETs.

  2. Coprecipitation of arsenate with metal oxides. 2. Nature, mineralogy, and reactivity of iron(III) precipitates.

    PubMed

    Violante, Antonio; Del Gaudio, Stefania; Pigna, Massimo; Ricciardella, Mariarosaria; Banerjee, Dipanjan

    2007-12-15

    Coprecipitation of arsenic with iron or aluminum occurs in natural environments and is a remediation technology used to remove this toxic metalloid from drinking water and hydrometallurgical solutions. In this work, we studied the nature, mineralogy, and reactivity toward phosphate of iron-arsenate coprecipitates formed at As(V)/Fe(III) molar ratios (R) of 0, 0.01, or 0.1 and at pH 4.0, 7.0, and 10.0 aged for 30 or 210 days at 50 degrees C and studied the desorption of arsenate. At R = 0, goethite and hematite (with ferrihydrite at pH 4.0 and 7.0) crystallized, whereas at R = 0.01, the formation of ferrihydrite increased and hematite crystallization was favored over goethite. In some samples, the morphology of hematite changed from rounded platy crystals to ellipsoids. At R = 0.1, ferrihydrite formed in all the coprecipitates and remained unchanged even after 210 days of aging. The surface area and chemical composition of the precipitates were affected by pH, R, and aging. Chemical dissolution of the samples showed that arsenate was present mainly in ferrihydrite, but at R = 0.01, it was partially incorporated into the structures of crystalline Fe oxides. The sorption of phosphate on to the coprecipitates was affected not only by the mineralogy and surface area of the samples but also by the amounts of arsenate present in the oxides. The samples formed at pH 4.0 and 7.0 and at R = 0.1 sorbed lower amounts of phosphate than the precipitates obtained at R = 0 or 0.01, despite the former having a larger surface area and showing only a presence of short-range ordered materials. This is mainly due to the fact that in the coprecipitates at R = 0.1 arsenate occupied many sorption sites, thus preventing phosphate sorption. Less than 20% of the arsenate present in the coprecipitates formed at R = 0.1 was removed by phosphate and more from the samples synthesized at pH 7.0 or 10.0 than at pH 4.0. Moreover, we found that more arsenate was desorbed by phosphate from a

  3. Cavitation modeling and diesel engine cylinder liners

    NASA Astrophysics Data System (ADS)

    Chandekar, Gautam; Pardue, Sally

    2003-10-01

    A common occurrence of cavitation damage is the waterside pitting of a wet sleeve liner in a diesel engine. The automotive industry utilizes an ultrasonic test of 20 kHz according to ASTM standards to quantify the effectiveness of engine coolant additives to prevent damage. However, recent tests indicate a mismatch between the ultrasonic test results and actual engine test runs. The focus of this study is to generate numerical models of bubble dynamics using already published literature. In most of the published papers higher-range frequencies (ultrasonic >15 kHz) are used. It is useful to explore the results of lower excitation frequencies as the vibrating frequencies of a diesel engine liner are between 500-9000 Hz. A Rayleigh-Plesset equation, nonlinear in nature, is used to plot the relation between bubble radius and time. Plots of the numerical solution from MATLAB are compared with plots published in the literature. Results from when the frequency of excitation is changed to the liner wall frequency and the fluid properties are changed to approximate engine conditions will be presented. Future work will examine the energy released by the bubble collapse and its correlation with erosion measured as mass change in a standard test button.

  4. Adverse local tissue reaction after 2 revision hip replacements for ceramic liner fracture

    PubMed Central

    Antoniac, Iulian; Negrusoiu, Mihai; Mardare, Mihai; Socoliuc, Claudiu; Zazgyva, Ancuţa; Niculescu, Marius

    2017-01-01

    Abstract Introduction: In younger patients, ceramic-on-ceramic (CoC) bearing surfaces are usually recommended for total hip replacement (THR) because of their low wear rate and longer expected functional life. Although technical advancements have reduced the risk of ceramic bearings fracture, this complication remains a major concern. Case description: We present the case of a 56-year-old patient undergoing 3 revision hip arthroplasties of the right hip due to ceramic liner fractures. Initial THR (2008) was performed with a CoC bearing, followed by liner fracture due to trauma a year later. The acetabular component and liner were replaced, with a minor incongruence between the old head and new insert. The 2nd ceramic insert fractured 3.5 years later, following minor trauma. Upon revision, the bearing surface was changed to metal-on-polyethylene (MoP). The performed retrieval analysis demonstrated stripe and rim wear, and evidence of adhesive wear. The patient was referred to us a month later, with a fistula on the lateral side of the hip, discharging black, petroleum-like liquid. Radiology showed well-fixed implants, no dislocation and no apparent polyethylene wear. Microbiological assessment of the discharge showed no infection. Intraoperatively massive metallosis was noticed, with stable acetabular and femoral components. The metal femoral head was heavily abraded, with almost 1% volumetric wear. Hematoxylin and eosin stained frozen tissue samples showed muscular and adipose tissue necrosis, while polarized light microscopy highlighted metal, polyethylene, and ceramic particles. Conclusion: The present case is yet another report showing the adverse outcomes of using MoP bearings for revision after ceramic liner fracture in THR. PMID:28489745

  5. A modeling approach for the purification of group III metals (Ga and In) by zone refining

    SciTech Connect

    Ghosh, K.; Dhar, S.; Mani, V. N.

    2008-07-15

    An 'experimental friendly' model for zone refining process is proposed which predicts effective zone length in each refining passes that would lead to maximal solute removal, thereby leading to ultrapurification of the material for use in high-end electronic applications. The effectiveness of the model is experimentally tested and validated by purifying gallium from 4N (99.99%) to 6N5 (99.99995%) purity level at 30% yield and {approx}6 N at 70% yield with respect to targeted metallic impurities such as, Zn, Cu, Al, Ca, Bi, Si, Pb, Ni, Mn, and Fe, as analyzed by inductively coupled plasma optical emission spectrometry, graphite furnace atomic absorption spectrometry, and high resolution inductively coupled plasma mass spectrometry techniques. The distribution coefficient (k) of all the targeted impurities, detected in the purified gallium, was found to be less than 1. By comparing the experimentally obtained axial concentration profiles with the theoretical calculations, the k values of some detected impurities, such as Ca and Al, are determined to be {approx}0.8, Pb and Bi to be 0.7, Cu to be 0.65, and Fe to be 0.68, which prove the efficiency of the proposed model in reducing the concentration of these vulnerable impurities significantly. Following the model and as evidenced from the theoretical predictions, degradation of material purification containing a mixture of impurities having k less than as well as greater than 1 was elucidated experimentally by zone refining of 4N6 indium. Only a 40% yield of 5N6 indium was obtained, thereby highlighting the intricacies and problem areas in ultrapurification of these types of material.

  6. Structural, magnetic and phonon properties of Cr(III)-doped perovskite metal formate framework [(CH3)2NH2][Mn(HCOO)3

    NASA Astrophysics Data System (ADS)

    Mączka, Mirosław; Gągor, Anna; Hermanowicz, Krzysztof; Sieradzki, Adam; Macalik, Lucyna; Pikul, Adam

    2016-05-01

    We have incorporated Cr(III) into [(CH3)2NH2][Mn(HCOO)3] (DMMn) multiferroic metal organic framework (MOF). The highest concentration of Cr(III) in the synthesized samples reached 15.9 mol%. The obtained samples were characterized by powder and single-crystal X-ray diffraction, DSC, magnetic susceptibility, dielectric, EPR, Raman and IR methods. These methods and the performed chemical analysis revealed that electrical charge neutrality after substitution of Cr(III) for Mn(II) is maintained by partial replacement of dimethylammonium (DMA+) cations by neutral HCOOH molecules. These changes in the chemical composition are responsible for weakening of the hydrogen bonds and decreased flexibility of the framework. This in turn leads to lowering of the ferroelectric phase transition temperature, observed around 185 K for undoped DMMn and around 155 K for the sample containing 3.1 mol% of Cr(III), and lack of macroscopic phase transition for the samples with Cr(III) content of 8.2 and 15.9 mol %. Another interesting effect observed for the studied samples is pronounced strengthening of the weak ferromagnetism of in Cr(III)-doped samples, associated with slight decrease of the ferromagnetic ordering temperature from 8.5 K for DMMn to 7.0 K for the sample with 15.9 mol % Cr(III) content.

  7. Stability of combustors with partial length acoustic liners

    NASA Technical Reports Server (NTRS)

    Mitchell, C. E.; Espander, W. R.; Baer, M. R.

    1972-01-01

    An analytical technique for the evaluation of combustion stability in rocket motors with partial length acoustic absorbers is presented. The combustors considered have concentrated combustion zones at the injector, finite mean flows, cylindrical cross sections, and acoustic liners of arbitrary length and impedance. Linear three dimensional oscillations in such combustion chambers are analyzed using an integral equation-iteration technique. Stability limits in terms of a combustion response factor are calculated for several values of Mach number, length to radius ratio, liner impedance, liner length, liner location, and nozzle admittance. Results indicate that increasing liner length increases combustor stability substantially at low Mach numbers but has a substantially smaller effect for larger Mach numbers. Increasing Mach numbers or length to radius ratio have destabilizing effects while liner location has only a minor effect on stability.

  8. Method for selectively controlling flow across slotted liners

    SciTech Connect

    Peavy, M.A.; Dees, J.M.

    1993-08-31

    A process is described for decreasing flow rate across the radial boundary of a selected interval in a well bore containing a slotted liner comprising: placing an explosive and an internally catalyzed resin solution inside an elongated container; locating the elongated container opposite the selected interval in the well bore where flow rate through the slotted liner is to be decreased; firing the explosive; and allowing the resin to cure on the slotted liner before initiating flow through the well. A method is described for decreasing production of unwanted fluids from a horizontal well containing a slotted liner comprising: placing an explosive and an internally catalyzed resin inside an elongated container; placing the elongated container opposite an interval in the horizontal well where unwanted fluid is entering the well bore through the slotted liner; firing the explosive; and permitting the resin to cure on the slotted liner before initiating flow in the well.

  9. Accelerated aging tests of liners for uranium mill tailings disposal

    SciTech Connect

    Barnes, S.M.; Buelt, J.L.; Hale, V.Q.

    1981-11-01

    This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing.

  10. The effect of electro-thermal and electro-choric instabilities and material strength on MagLIF liner stability

    NASA Astrophysics Data System (ADS)

    Pecover, James; Chittenden, Jeremy

    2015-11-01

    Magnetized liner inertial fusion (MagLIF) is a promising route to controlled thermonuclear fusion. The concept involves magnetically imploding a metal liner containing fuel with an azimuthal magnetic field (Bz) ; a key limitation of such systems is the magneto-Rayleigh-Taylor (MRT) instability. MagLIF relevant liner implosions with Bz = 0 carried out at SNL showed high amplitude MRT growth; we present a quantitative comparison between experimental results and 3D results from our MHD code Gorgon, demonstrating closer agreement for the MRT properties with the inclusion of electro-thermal and electro-choric instabilities (ETI and ECI) and material strength. The ETI and ECI result in early time azimuthally correlated structures which provide a seed for the MRT. Material strength increases the ETI amplitude due to positive feedback during the solid phase of the liner. Similar liner implosions with Bz exhibited a re-orientation of the MRT into helical structures, which are yet to be reproduced by simulations without an artificial helical initialisation. Our 3D Gorgon results with Bz show helices prior to vapourisation; these occur at initially positive angles before changing sign, tending to zero later in time. This angle does not follow the relative magnitudes of Bz and Bθ as would be expected for the MRT. The angle instead follows the ratio of axial and azimuthal currents (induced by compression or rarefaction of the initial Bz) , indicating an electro-thermal origin.

  11. Explorations of a series of second order nonlinear optical materials based on monovalent metal gold(III) iodates.

    PubMed

    Huang, Chao; Hu, Chun-Li; Xu, Xiang; Yang, Bing-Ping; Mao, Jiang-Gao

    2013-10-07

    The syntheses, crystal structures, and characterizations of a series of monovalent metal gold(III) iodates, namely, α-NaAu(IO3)4, β-NaAu(IO3)4, RbAu(IO3)4, α-CsAu(IO3)4, β-CsAu(IO3)4, and AgAu(IO3)4 are reported. Their structures feature Au(IO3)4(-) anions that are separated by alkali metal ions or silver(I) ions. The Au(IO3)4(-) anions in the polar α-NaAu(IO3)4, RbAu(IO3)4, and α-CsAu(IO3)4 are polar with all four iodate groups being located only above (or below) the AuO4 square plane (cis- configuration). α-NaAu(IO3)4, RbAu(IO3)4, and α-CsAu(IO3)4 display moderate strong Second-Hamonic Generation (SHG) responses of 1.17 ×, 1.33 ×, and 1.17 × KTP (KTiOPO4), respectively, and all three materials are type-I phase-matchable. The Au(IO3)4(-) anions in centrysymmetric β-NaAu(IO3)4, β-CsAu(IO3)4, and AgAu(IO3)4 are nonpolar with the four iodate groups of the Au(IO3)4(-) anion being located both above and below the AuO4 square plane (trans- configuration). IR and UV spectra, luminescent and ferroelectric properties have also been measured. Theoretical calculations of their optical properties based on density functional theory (DFT) methods were performed by using the CASTEP total-energy code.

  12. Measurement of the solar neutrino capture rate with gallium metal, part III

    SciTech Connect

    Elliott, Steven Ray

    2008-01-01

    The Russian-American experiment SAGE began to measure the solar neutrino capture rate with a target of gallium metal in December 1989. Measurements have continued with only a few brief interruptions since that time. In this article we present the experimental improvements in SAGE since its last published data summary in December 2001. Assuming the solar neutrino production rate was constant during the period of data collection, combined analysis of 168 extractions through December 2007 gives a capture rate of solar neutrinos with energy more than 233 keY of 65.4{sup +3.1}{sub 3.0} (stat) {sup +2.6}{sub -2.8} (syst) SNU. The weighted average of the results of all three Ga solar neUlrino experiments, SAGE, Gallex, and GNO, is now 66.1 {+-} 3.1 SNU, where statistical and systematic uncertainties have been combined in quadrature. During the recent period of data collection a new test of SAGE was made with a reactor-produced {sup 37}Ar neutrino source. The ratio of observed to calculated rates in this experiment, combined with the measured rates in the three prior {sup 51}Cr neutrino-source experiments with Ga, is 0.88 {+-} 0.05. A probable explanation for this low result is that the cross section for neutrino capture by the two lowest-lying excited states in {sup 71}Ge has been overestimated. If we assume these cross sections are zero, then the standard solar model including neutrino oscillations predicts a total capture rate in Ga in the range of 63--67 SNU with an uncertainly of about 5%, in good agreement with experiment. We derive the current value of the pp neutrino flux produced in the Sun to be {phi}{sup {circle_dot}}{sub pp} = (6.1 {+-} 0.8) x 10{sup 10}/(cm{sup 2} s), which agrees well with the flux predicted by the standard solar model. Finally, we make several tests and show that the data are consistent with the assumption that the solar neutrino production rate is constant in time.

  13. Shaped Charge Liner Materials: Resources, Processes, Properties, Costs, and Applications

    DTIC Science & Technology

    1991-02-01

    SUBTITLE 5. FUNDING NUMBERS Shaped Charge Liner Materials: Resources, Processes, Properties, Costs, and Applications 2 6. AUTHOC Steven M. Buc 7...summaries of the mineral availability, Cq prmarymetal refinement processeb, material costs in raw form and as finished shaped charge liners , relevant... liner materials. 94-11479 gI 14, SUBJECT TERMS iSt NUMBER OF PAGIS 13chrg wrhad :xplosively formed penetrators material R. PRCE COEV" processing

  14. Composite liner, multi-megabar shock driver development

    SciTech Connect

    Bartsch, R.R.; Clark, D.A.; Morgan, D.V.

    1998-12-31

    A magnetically imploded, cylindrical, multi-layer liner is under development for use as an equation of state shock driver using energetic, pulsed-power sources. The stability and uniformity of the imploding liner has been investigated on the Pegasus pulsed-power facility at liner velocities of >7 mm/usec. Using a thick aluminum driver layer to carry the current and a platinum impactor layer to generate the shock on impact with a target, the expected platinum-on-platinum shock level is 6 to 8 Mbar for operation of the Pegasus capacitor bank at the maximum charge voltage of 90 kV. The initial liner design utilized 8 grams of aluminum with a 1 gram (12-micron thick) layer of platinum on the inside. The inner surface was observed with flash radiography oriented transversely to the axis of the collapsing liner, and with fiber-optic time-of-arrival detectors on the target. Short wavelength perturbations of the inner surface along the axial direction were observed with amplitudes between 200 to 400 microns. A second liner was evaluated with increased aluminum mass and thickness to avoid drive current penetration and the resulting melting and susceptibility to Rayleigh Taylor instabilities. With 10 grams of aluminum at an initial radius of 2.5 cm, the initial liner thickness was almost 50% greater than for the first liner. This liner was observed to be more uniform at impact than the initial design, with perturbed amplitudes less than 100 to 200 microns at wavelengths of a few millimeters. Based on these results a third experiment is being prepared with the 10 gram aluminum liner of the second design and with a 1 gram, 15 micron platinum impactor layer. Liner stability measurements will be presented, application of this liner system to EOS measurement will be discussed, and the evolution to higher energy experiments on ATLAS will be presented.

  15. LIQUID BUTANE FILLED LOAD FOR A LINER DRIVEN PEGASUS EXPERIMENT

    SciTech Connect

    M.A. SALAZAR; W. ANDERSON; ET AL

    2001-06-01

    A hydrogen rich, low density liquid, contained within the internal volume of a cylindrical liner, was requested of the Polymers and Coatings Group (MST-7) of the Los Alamos Materials Science Division for one of the last liner driven experiments conducted on the Los Alamos Pegasus facility. The experiment was a continuation of the Raleigh-Taylor hydrodynamics series of experiments and associated liners that have been described previously [1,2].

  16. Liquid butane filled load for a liner driven Pegasus experiment.

    SciTech Connect

    Salazar, M. A.; Armijo, E. V.; Anderson, W. E.; Atchison, W. L.; Bartos, J. J.; Garcia, F.; Randolph, B.; Sheppard, M. G.; Stokes, J. L.

    2001-01-01

    A hydrogen rich, low density liquid, contained within the internal volume of a cylindrical liner, was requested of the Polymers and Coatings Group (MST-7) of the Los Alamos Materials Science Division for one of the last liner driven experiments conducted on the Los Alamos Pegasus facility. The experiment (Fig.1) was a continuation of the Raleigh-Taylor hydrodynamics series of experiments and associated liners that have been described previously.

  17. Probing off-Hugoniot states in Ta, Cu, and Al to 1000 GPa compression with magnetically driven liner implosions

    NASA Astrophysics Data System (ADS)

    Lemke, R. W.; Dolan, D. H.; Dalton, D. G.; Brown, J. L.; Tomlinson, K.; Robertson, G. R.; Knudson, M. D.; Harding, E.; Mattsson, A. E.; Carpenter, J. H.; Drake, R. R.; Cochrane, K.; Blue, B. E.; Robinson, A. C.; Mattsson, T. R.

    2016-01-01

    We report on a new technique for obtaining off-Hugoniot pressure vs. density data for solid metals compressed to extreme pressure by a magnetically driven liner implosion on the Z-machine (Z) at Sandia National Laboratories. In our experiments, the liner comprises inner and outer metal tubes. The inner tube is composed of a sample material (e.g., Ta and Cu) whose compressed state is to be inferred. The outer tube is composed of Al and serves as the current carrying cathode. Another aluminum liner at much larger radius serves as the anode. A shaped current pulse quasi-isentropically compresses the sample as it implodes. The iterative method used to infer pressure vs. density requires two velocity measurements. Photonic Doppler velocimetry probes measure the implosion velocity of the free (inner) surface of the sample material and the explosion velocity of the anode free (outer) surface. These two velocities are used in conjunction with magnetohydrodynamic simulation and mathematical optimization to obtain the current driving the liner implosion, and to infer pressure and density in the sample through maximum compression. This new equation of state calibration technique is illustrated using a simulated experiment with a Cu sample. Monte Carlo uncertainty quantification of synthetic data establishes convergence criteria for experiments. Results are presented from experiments with Al/Ta, Al/Cu, and Al liners. Symmetric liner implosion with quasi-isentropic compression to peak pressure ˜1000 GPa is achieved in all cases. These experiments exhibit unexpectedly softer behavior above 200 GPa, which we conjecture is related to differences in the actual and modeled properties of aluminum.

  18. Probing off-Hugoniot states in Ta, Cu, and Al to 1000 GPa compression with magnetically driven liner implosions

    DOE PAGES

    Lemke, R. W.; Dolan, D. H.; Dalton, D. G.; ...

    2016-01-07

    We report on a new technique for obtaining off-Hugoniot pressure vs. density data for solid metals compressed to extreme pressure by a magnetically driven liner implosion on the Z-machine (Z) at Sandia National Laboratories. In our experiments, the liner comprises inner and outer metal tubes. The inner tube is composed of a sample material (e.g., Ta and Cu) whose compressed state is to be inferred. The outer tube is composed of Al and serves as the current carrying cathode. Another aluminum liner at much larger radius serves as the anode. A shaped current pulse quasi-isentropically compresses the sample as itmore » implodes. The iterative method used to infer pressure vs. density requires two velocity measurements. Photonic Doppler velocimetry probes measure the implosion velocity of the free (inner) surface of the sample material and the explosion velocity of the anode free (outer) surface. These two velocities are used in conjunction with magnetohydrodynamic simulation and mathematical optimization to obtain the current driving the liner implosion, and to infer pressure and density in the sample through maximum compression. This new equation of state calibration technique is illustrated using a simulated experiment with a Cu sample. Monte Carlo uncertainty quantification of synthetic data establishes convergence criteria for experiments. Results are presented from experiments with Al/Ta, Al/Cu, and Al liners. Symmetric liner implosion with quasi-isentropic compression to peak pressure ~1000 GPa is achieved in all cases. Lastly, these experiments exhibit unexpectedly softer behavior above 200 GPa, which we conjecture is related to differences in the actual and modeled properties of aluminum.« less

  19. Probing off-Hugoniot states in Ta, Cu, and Al to 1000 GPa compression with magnetically driven liner implosions

    SciTech Connect

    Lemke, R. W.; Dolan, D. H.; Dalton, D. G.; Brown, J. L.; Tomlinson, K.; Robertson, G. R.; Knudson, M. D.; Harding, E.; Mattsson, A. E.; Carpenter, J. H.; Drake, R. R.; Cochrane, K.; Blue, B. E.; Robinson, A. C.; Mattsson, T. R.

    2016-01-07

    We report on a new technique for obtaining off-Hugoniot pressure vs. density data for solid metals compressed to extreme pressure by a magnetically driven liner implosion on the Z-machine (Z) at Sandia National Laboratories. In our experiments, the liner comprises inner and outer metal tubes. The inner tube is composed of a sample material (e.g., Ta and Cu) whose compressed state is to be inferred. The outer tube is composed of Al and serves as the current carrying cathode. Another aluminum liner at much larger radius serves as the anode. A shaped current pulse quasi-isentropically compresses the sample as it implodes. The iterative method used to infer pressure vs. density requires two velocity measurements. Photonic Doppler velocimetry probes measure the implosion velocity of the free (inner) surface of the sample material and the explosion velocity of the anode free (outer) surface. These two velocities are used in conjunction with magnetohydrodynamic simulation and mathematical optimization to obtain the current driving the liner implosion, and to infer pressure and density in the sample through maximum compression. This new equation of state calibration technique is illustrated using a simulated experiment with a Cu sample. Monte Carlo uncertainty quantification of synthetic data establishes convergence criteria for experiments. Results are presented from experiments with Al/Ta, Al/Cu, and Al liners. Symmetric liner implosion with quasi-isentropic compression to peak pressure ~1000 GPa is achieved in all cases. Lastly, these experiments exhibit unexpectedly softer behavior above 200 GPa, which we conjecture is related to differences in the actual and modeled properties of aluminum.

  20. Durability of organobentonite-amended liner for decelerating chloroform transport.

    PubMed

    He, Shichong; Zhu, Lizhong

    2016-04-01

    Chloroform is added to landfill for suppressing methane generation, which however may transport through landfill liners and lead to contamination of groundwater. To decelerate chloroform transport, the enhanced sorption ability of clay liners following organobentonite addition was tested. In this study, we used batch sorption to evaluate sorption capacity of chloroform to organobentonite, followed by column tests and model simulations for assessing durability of different liners. Results show that adding 10% CTMAB-bentonite (organobentonite synthesized using cetyltrimethylammonium bromide) increased the duration of a bentonite liner by 88.5%. CTMAB-bentonite consistently showed the highest sorption capacity (Qm) among six typical organobentonites under various environmental conditions. The removal rate of chloroform by CTMAB-bentonite was 3.6-23 times higher than that by natural soils. According to the results derived by model simulation, a 70-cm 10% CTMAB-bentonite liner exhibited much better durability than a 100-cm compact clay liner (CCL) and natural bentonite liner evidenced by the delayed and lower peak of eluent concentration. A minimum thickness of 65.8 cm of the 10% CTMAB-bentonite liner could completely sorb the chloroform in a 100-m-high landfill. The 10% CTMAB-bentonite liner exhibiting much better durability has the promise for reducing environmental risk of chloroform in landfill.

  1. Variable-Depth Liner Evaluation Using Two NASA Flow Ducts

    NASA Technical Reports Server (NTRS)

    Jones, M. G.; Nark, D. M.; Watson, W. R.; Howerton, B. M.

    2017-01-01

    Four liners are investigated experimentally via tests in the NASA Langley Grazing Flow Impedance Tube. These include an axially-segmented liner and three liners that use reordering of the chambers. Chamber reordering is shown to have a strong effect on the axial sound pressure level profiles, but a limited effect on the overall attenuation. It is also shown that bent chambers can be used to reduce the liner depth with minimal effects on the attenuation. A numerical study is also conducted to explore the effects of a planar and three higher-order mode sources based on the NASA Langley Curved Duct Test Rig geometry. A four-segment liner is designed using the NASA Langley CDL code with a Python-based optimizer. Five additional liner designs, four with rearrangements of the first liner segments and one with a redistribution of the individual chambers, are evaluated for each of the four sources. The liner configuration affects the sound pressure level profile much more than the attenuation spectra for the planar and first two higher-order mode sources, but has a much larger effect on the SPL profiles and attenuation spectra for the last higher-order mode source. Overall, axially variable-depth liners offer the potential to provide improved fan noise reduction, regardless of whether the axially variable depths are achieved via a distributed array of chambers (depths vary from chamber to chamber) or a group of zones (groups of chambers for which the depth is constant).

  2. Optimization and Control of Acoustic Liner Impedance with Bias Flow

    NASA Technical Reports Server (NTRS)

    Wood, Houston; Follet, Jesse

    2000-01-01

    Because communities are impacted by steady increases in aircraft traffic, aircraft noise continues to be a growing problem for the growth of commercial aviation. Research has focused on improving the design of specific high noise source areas of aircraft and on noise control measures to alleviate noise radiated from aircraft to the surrounding environment. Engine duct liners have long been a principal means of attenuating engine noise. The ability to control in-situ the acoustic impedance of a liner would provide a valuable tool to improve the performance of liners. The acoustic impedance of a liner is directly related to the sound absorption qualities of that liner. Increased attenuation rates, the ability to change liner acoustic impedance to match various operating conditions, or the ability to tune a liner to more precisely match design impedance represent some ways that in-situ impedance control could be useful. With this in mind, the research to be investigated will focus on improvements in the ability to control liner impedance using a mean flow through the liner which is referred to as bias flow.

  3. Stress Distribution under Commercial Denture Liners- A Finite Element and Clinical Analysis

    PubMed Central

    Chaturvedi, Saurabh; Verma, Ashok Kumar; Ali, Mariyum; Nagendra, Amrita; Chaturvedi, Mudita

    2016-01-01

    Introduction Previous studies have shown that 20-30% of denture users have been dissatisfied with their dentures. Aim To evaluate the stress pattern under elastic and viscoelastic denture liners using 3-Dimensional Finite Element Analysis (FEA) and its clinical correlation using a questionnaire. Materials and Methods The study had both in-vitro and in-vivo phases. In in-vitro phase fabrication of a virtual parametric model of edentulous maxilla and dentures with overlying mucosa was made. A virtual load of 166N was analyzed at three points (Point A=anterior ridge, Point B=right posterior ridge and Point C=left posterior ridge). For the in-vivo phase, 20 edentulous patients were provided conventional complete dentures (Group-I). The dentures were lined with silicone (elastic) liners (Group-II) and acrylic resins (viscoelastic) liners (Group-III) at regular (2 months) intervals. After each reline, the patients were evaluated using food eating ability and denture assessment questionnaires. The results were statistically analyzed. The statistical analysis was done using SPSS (Statistical Package for Social Sciences) version 15.0 statistical analysis software. Other than standard statistical test Analysis of Variance (ANOVA) and Post-Hoc tests (Tukey-HSD) were used. Results At loading, the in-vitro result for Groups–II and III revealed pressures of 0.074231N and 0.0678364N at Point A, 0.098764N and 0.093642N at Point B, and 0.099876N and 0.093746N at Point C respectively. The in-vivo study revealed that the mean quality of life score for different groups ranged from 23.65±4.00 (Group I) to 33.10±6.15 (Group III). The mean quality of life score for Group II was 29.50±5.08. Conclusion The viscoelastic liner provided the most uniform stress distribution and performed better than an elastic liner with hard, firm and soft foods. PMID:28208996

  4. Third-Order Nonlinear Optic and Optical Limiting Properties of a Mn(iii) Transition Metal Complex

    NASA Astrophysics Data System (ADS)

    Karakas, Asli; Elmali, Ayhan; Yahsi, Yasemin; Kara, Hulya

    N,N‧-bis(5-bromosalicylidene)propane-1,2-diamine-O,O‧,N,N‧)-manganese(III) chloride transition metal complex has been synthesized and characterized by elemental analysis and UV-vis spectroscopy. Its crystal structure has been determined using X-ray diffraction analysis. To provide an insight into the optical limiting (OL) behavior of the title compound, the third-order nonlinear optical (NLO) properties, one-photon absorption (OPA) and two-photon absorption (TPA) characterizations have been theoretically investigated by means of the time-dependent Hartree-Fock (TDHF), AM1 and configuration interaction (CI) methods, respectively. According to ab initio calculation results, the examined molecule exhibits second hyperpolarizabilities (γ) with non-zero values at the positions of TPA peaks, implying microscopic third-order optical nonlinearity. The maximum OPA wavelengths recorded by linear optical experiment and quantum mechanical computations are estimated in the UV region to be shorter than 400 nm, showing good optical transparency to the visible light. The TPA cross-sections (δ(ω)) at λ max(2) values indicate that the synthesized compound might possess OL phenomena, which are in accord with the experimental observations on the manganese complexes in the literature.

  5. A novel method for study of the aggregation of protein induced by metal ion aluminum(III) using resonance Rayleigh scattering technique

    NASA Astrophysics Data System (ADS)

    Long, Xiufen; Zhang, Caihua; Cheng, Jiongjia; Bi, Shuping

    2008-01-01

    We present a novel method for the study of the aggregation of protein induced by metal ion aluminum(III) using resonance Rayleigh scattering (RRS) technique. In neutral Tris-HCl medium, the effect of this aggregation of protein results in the enhancement of RRS intensity and the relationship between the enhancement of the RRS signal and the Al concentration is nonlinear. On this basis, we established a new method for the determination of the critical induced-aggregation concentrations ( CCIAC) of metal ion Al(III) inducing the protein aggregation. Our results show that many factors, such as, pH value, anions, salts, temperature and solvents have obvious effects. We also studied the extent of aggregation and structural changes using ultra-violet spectrometry, protein intrinsic fluorescence and circular dichroism to further understand the exact mechanisms of the aggregation characteristics of proteins induced by metal ion Al(III) at the molecular level, to help us to develop effective methods to investigate the toxicity of metal ion Al, and to provide theoretical and quantitative evidences for the development of appropriate treatments for neurodementia such as Parkinson's disease, Alzheimer's disease and dementia related to dialysis.

  6. 30 CFR 250.425 - What are the requirements for pressure testing liners?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... shoe, or subsequent liner shoes if set. The District Manager may approve or require other liner test... formation fracture pressure at the casing shoe into which the liner is lapped. (c) You may not resume...

  7. Chiral-at-Metal Rh(III) Complex-Catalyzed Decarboxylative Michael Addition of β-Keto Acids with α,β-Unsaturated 2-Acyl Imidazoles or Pyridine.

    PubMed

    Li, Shi-Wu; Gong, Jun; Kang, Qiang

    2017-03-17

    A newly prepared chiral-at-metal Rh(III) complex-catalyzed, highly efficient enantioselective decarboxylative Michael addition of β-keto acids with α,β-unsaturated 2-acyl imidazoles or pyridine has been developed, affording the corresponding adducts in 94-98% yield with up to 96% enantioselectivity. This protocol exhibits remarkable reactivity, as the complex with a Rh(III) loading as low as 0.05 mol % can catalyze the decarboxylative Michael addition on a gram scale without loss of enantioselectivity.

  8. Ligational behavior of clioquinol antifungal drug towards Ag(I), Hg(II), Cr(III) and Fe(III) metal ions: Synthesis, spectroscopic, thermal, morphological and antimicrobial studies

    NASA Astrophysics Data System (ADS)

    El-Megharbel, Samy M.; Refat, Moamen S.

    2015-04-01

    This article presents a synthesis, characterization, theoretical and biological (anti-bacterial, and anti-fugal) evaluation studies of Ag(I), Hg(II), Cr(III) and Fe(III) complexes of clioquinol (CQ) drug ligand. Structures of the titled complexes cited herein were discussed using elemental analyses and spectral measurements e.g., IR, 1H NMR, and electronic studies. The results confirmed the formation of the clioquinol complexes by three molar ratios (1:1) for Ag(I), (1:2) for Hg(II) and (1:3) for both Cr(III) and Fe(III) metal ions. The clioquinol reacts as a bidentate chelate bound to all respected metal ions through the oxygen and nitrogen of quinoline-8-ol. The metal(II) ions coordinated to clioquinol ligand through deprotonation of sbnd OH terminal group. Infrared and 1H NMR spectral data confirm that coordination is via the oxygen of phenolic group and nitrogen atom of quinoline moiety. The molar conductance measurements of the CQ complexes in DMSO correspond to be non-electrolyte nature. Thus, these complexes may be formulated as [Ag(CQ)(H2O)2] H2O, [Hg(CQ)2]ṡ2H2O, [Cr(CQ)3] and [Fe(CQ)3]H2O. The Coats-Redfern method, the kinetic thermodynamic parameters like activation energies (E∗), entropies (ΔS∗), enthalpies (ΔH∗), and Gibbs free energies (ΔG∗) of the thermal decomposition reactions have been deduced from thermogravimetric curves (TG) with helpful of differential thermo gravimetric (DTG) curves. The narrow size distribution in nano-scale range for the clioquinol complexes have been discussed using X-ray powder diffraction (XRD), scanning electron microscope (SEM), and X-ray energy dispersive spectrometer (EDX) analyzer.

  9. Neutron Diffraction Characterization of Residual Strain in Welded Inconel 718 for NASA Space Shuttle Flow Liners

    SciTech Connect

    Rathod, C.R.; Vaidyanathan, R.; Livescu, V.; Clausen, B.; Bourke, M. A. M.; Notardonato, W.U.; Femminineo, M.

    2004-06-28

    This work quantitatively assesses residual strains and stresses associated with the weld repair process used to repair cracks on NASA's space shuttle flow liners. The coupons used in this investigation were made of the same INCONEL 718 alloy used for the flow liners. They were subjected to identical welding and certification procedures that were carried out on the space shuttle. Neutron diffraction measurements at Los Alamos National Laboratory determined residual strains at selected locations in a welded coupon at 293 K and 135 K. The weld repair process introduced Mises effective residual stresses of up to 555 MPa. On comparing the measurements at 293 K and 135 K, no significant change to the residual strain profile was noted at the low temperature. This indicated minimal mismatch in the coefficients of thermal expansion between the base metal and the weld.

  10. Full-Scale GRCop-84 Combustion Chamber Liner Preform Fabricated Successfully

    NASA Technical Reports Server (NTRS)

    Ellis, David L.; Russell, Carolyn K.; Goudy, Rick

    2005-01-01

    GRCop-84 (Cu-8 at.% Cr-4 at.% Nb) has been under development at the NASA Glenn Research Center for several years. The alloy possesses a unique combination of good thermal conductivity, high elevated temperature strength, long creep life, and long low-cycle- fatigue. The alloy is also more oxidation resistant than pure copper and most competitive alloys. The combination of properties has attracted attention from major rocket engine manufacturers who are interested in the alloy for the combustion chamber liner in their next generation of regeneratively cooled engines. Before GRCop-84 can be used in a main combustion chamber application, it must be demonstrated that the alloy can be made successfully to the large sizes and proper shape needed and that it retain useful properties. Recent efforts have successfully demonstrated the ability to fabricate a liner preform via metal spinning that retains the alloy s strength even in the welded sections.

  11. Evaluation of Skin Friction Drag for Liner Applications in Aircraft

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Brown, Martha C.; Jasinski, Christopher M.

    2016-01-01

    A parameter that is gaining significance in the evaluation of acoustic liner performance is the skin friction drag induced by air flow over the liner surface. Estimates vary widely regarding the amount of drag the liner induces relative to a smooth wall, from less than a 20% increase to nearly 100%, and parameters such as face sheet perforate hole diameter, percent open area, and sheet thickness are expected to figure prominently in the skin friction drag. Even a small increase in liner drag can impose an economic penalty, and current research is focused on developing 'low drag' liner concepts, with the goal being to approach the skin friction drag of a smooth wall. The issue of skin friction drag takes on greater significance as airframe designers investigate the feasibility of putting sound absorbing liners on the non-lifting surfaces of the wings and fuselage, for the purpose of reducing engine noise reflected and scattered toward observers on the ground. Researchers at the NASA Langley Research Center have embarked on investigations of liner skin friction drag with the aims of: developing a systematic drag measurement capability, establishing the drag of current liners, and developing liners that produce reduced drag without compromising acoustic performance. This paper discusses the experimental procedures that have been developed to calculate the drag coefficient based on the change in momentum thickness and the companion research program being carried out to measure the drag directly using a force balance. Liner samples that are evaluated include a solid wall with known roughness and conventional liners with perforated facesheets of varying hole diameter and percent open area.

  12. General synthetic approach to heterostructured nanocrystals based on noble metals and I-VI, II-VI, and I-III-VI metal chalcogenides.

    PubMed

    Liu, Minghui; Zeng, Hua Chun

    2014-08-19

    Solid metal precursors (alloys or monometals) can serve both as a starting template and as a source material for chemical transformation to metal chalcogenides. Herein, we develop a simple solution-based strategy to obtain highly monodisperse noble-metal-based heterostructured nanocrystals from such precursor seeds. By utilizing chemical and structural inhomogeneity of these metal seeds, in this work, we have synthesized a total of five I-VI (Ag2S, Ag2Se, Ag3AuS2, Ag3AuSe2, and Cu9S5), three II-VI (CdS, CdSe, and CuSe), and four I-III-VI (AgInS2, AgInSe2, CuInS2, and CuInSe2) chalcogenides, together with their fifteen associated heterodimers (Au-Ag2S, Au-Ag2Se, Au-Ag3AuS2, Au-Ag3AuSe2, Au-AgInS2, Au-AgInSe2, Au-CdS, Au-CdSe, Ag-Ag2S, Ag-AgInS2, Au-Cu9S5, Au-CuInS2, Au-CuSe, Au-CuInSe2, and Pt-AgInS2) to affirm the process generality. Briefly, by adding elemental sulfur or selenium to AuAg alloy seeds and tuning the reaction conditions, we can readily obtain phase-pure Au-Ag2S, Au-Ag2Se, Au-Ag3AuS2, and Au-Ag3AuSe2 heterostructures. Similarly, we can also fabricate Au-AgInS2 and Au-AgInSe2 heterostructures from the AuAg seeds by adding sulfur/selenium and indium precursors. Furthermore, by partial or full conversion of Ag seeds, we can prepare both single-phase Ag chalcogenide nanocrystals and Ag-based heterostructures. To demonstrate wide applicability of this strategy, we have also synthesized Au-based binary and ternary Cu chalcogenide (Au-Cu9S5, Au-CuSe, Au-CuInS2, and Au-CuInSe2) heterostructures from alloy seeds of AuCu and Pt chalcogenides (e.g., Pt-AgInS2) from alloy seeds of PtAg. The structure and composition of the above products have been confirmed with X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and energy-dispersive X-ray spectroscopy methods. A kinetic investigation of the formation mechanism of these heterostructures is brought forward using Au-AgInS2 and Ag-CuInS2 as model examples.

  13. Tunable electronic and magnetic properties in germanene by alkali, alkaline-earth, group III and 3d transition metal atom adsorption.

    PubMed

    Li, Sheng-shi; Zhang, Chang-wen; Ji, Wei-xiao; Li, Feng; Wang, Pei-ji; Hu, Shu-jun; Yan, Shi-shen; Liu, Yu-shen

    2014-08-14

    We performed first-principles calculations to study the adsorption characteristics of alkali, alkali-earth, group III, and 3d transition-metal (TM) adatoms on germanene. We find that the adsorption of alkali or alkali-earth adatoms on germanene has minimal effects on geometry of germanene. The significant charge transfer from alkali adatoms to germanene leads to metallization of germanene, whereas alkali-earth adatom adsorption, whose interaction is a mixture of ionic and covalent, results in semiconducting behavior with an energy gap of 17-29 meV. For group III adatoms, they also bind germanene with mixed covalent and ionic bonding character. Adsorption characteristics of the transition metals (TMs) are rather complicated, though all TM adsorptions on germanene exhibit strong covalent bonding with germanene. The main contributions to the strong bonding are from the hybridization between the TM 3d and Ge pz orbitals. Depending on the induced-TM type, the adsorbed systems can exhibit metallic, half-metallic, or semiconducting behavior. Also, the variation trends of the dipole moment and work function with the adsorption energy across the different adatoms are discussed. These findings may provide a potential avenue to design new germanene-based devices in nanoelectronics.

  14. A heterotrimetallic Ir(III), Au(III) and Pt(II) complex incorporating cyclometallating bi- and tridentate ligands: simultaneous emission from different luminescent metal centres leads to broad-band light emission.

    PubMed

    Muñoz-Rodríguez, Rebeca; Buñuel, Elena; Fuentes, Noelia; Williams, J A Gareth; Cárdenas, Diego J

    2015-05-14

    Di- and tri-nuclear metal complexes incorporating gold(III), iridium(III) and platinum(II) units linked via a 1,3,5-triethynylbenzene core are reported, together with the corresponding mononuclear complexes as models. The gold(III) and platinum(II) units comprise tridentate, cyclometallating, C^N^C and N^N^C-coordinating ligands, respectively, with the Ar-C≡C- directly bound to the metal at the fourth coordination site. The iridium moiety is an Ir(ppy)2(acac) unit bound to the triethynylbenzene through a phenyl substituent at the 3-position of the acac ligand. The multinuclear compounds are prepared, using a modular synthetic strategy, from the monometallic complexes. All of the compounds are luminescent in solution at room temperature, and their photophysical properties were studied. The triplet excited state energies of the mononuclear complexes lie in the order Au > Ir > Pt. Consistent with this order, energy transfer from Au to Ir and from Au to Pt is observed, leading to quenching of the Au emission in the gold-containing multinuclear complexes. Energy transfer from Ir to Pt occurs at a rate that only partially quenches the Ir-based emission. As a result, the dinuclear Ir-Pt and trinuclear Au-Ir-Pt complexes display broad emission across most of the visible region of the spectrum.

  15. Liner hanger assembly with setting tool

    SciTech Connect

    Dockins, R.R. Jr.; Lindsey, H.E. Jr.

    1987-12-15

    A setting tool and liner hanger for setting a liner in a well bore traversing earth formations is described including: a tubular outer hanger member adapted for coupling to a depending liner, the outer hanger member having circumferentially disposed elongated slip openings, elongated slip members disposed in the slip openings for movement of the slip members from a first retracted position within the outer hanger member to an extended position in engagement with the wall of a well casing, a setting tool having a tubular inner member adapted for coupling to a drill string; hydraulic slip setting means for response to hydraulic pressure for producing a slip setting force and mechanical slip setting means for producing a slip setting force, the hydraulic slip setting means and the mechanical slip setting means being carried by the tubular inner member; coupling means for releasably coupling the tubular inner member to the outer hanger member. The slip setting means include an upper dog member and a lower dog member which are respectively connected to the hydraulic slip setting means and to the mechanical slip setting means wherein the dog members are movable longitudinally relative to the tubular member in response to a slip setting force for moving the slip members from the first retracted position to the extended position. The hydraulic slip setting means and the mechanical slip setting means for moving the upper and lower dog members respectively include selectively operable actuator means for selectively moving one of the dog members longitudinally relative to the tubular inner member and the outer hanger member.

  16. Paradigm shift from alkaline (earth) metals to early transition metals in fluoroorganometal chemistry: perfluoroalkyl titanocene(III) reagents prepared via not titanocene(II) but titanocene(III) species.

    PubMed

    Fujiu, Motohiro; Hashimoto, Ryota; Nakamura, Yuzo; Aikawa, Kohsuke; Ito, Shigekazu; Mikami, Koichi

    2014-02-17

    Perfluoroalkyl (RF) titanocene reagents [Cp2Ti(III)RF] synthesized via [Cp2Ti(III)Cl] rather than [Cp2Ti(II)] show new types of perfluoroalkylation reactions. The [Cp2Ti(III)RF] reagents exhibit a wide variety of reactivity with carbonyl compounds including esters and nitriles, and selectivities far higher than those reported for conventional RFLi and RFMgX reagents.

  17. Novel transition metal complexes of 4-hydroxy-coumarin-3-thiocarbohydrazone: Pharmacodynamic of Co(III) on rats and antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Mosa, A. I.; Emara, Adel A. A.; Yousef, J. M.; Saddiq, A. A.

    2011-10-01

    A new series of stable transition metal complexes of the formula M(L)X·S, where M = Cu(II), Ni(II), Co(III), Cr(III) and Fe(III) and L is the deprotonated ligand of 4-hydroxy-coumarin-3-thiocarbohydrazone, X = Cl -, NO 3- or CH 3COO - and S = H 2O and/or EtOH. The HL ligand was prepared by the reaction of 3-formyl-4-hydroxy-coumarine with thiocarbohydrazide in the molar ratio 1:1. The HL ligand and its metal complexes were characterized by elemental analysis, 1H NMR, IR and electronic spectra, and molar conductance and magnetic measurements and thermal gravimetric analysis (TGA). The HL ligand acts as a monobasic tridentate ONS donor in all metal complexes, and coordinated through the phenolic OH, azomethine nitrogen and thione sulfur. Electronic spectra with magnetic moments suggested varieties of geometries around the central metal atoms. Thermal gravimetric analysis indicates that the complexes are stable up to 300 °C, and release the uncoordinated and/or coordinated H 2O/solvent molecules, which is accompanied by a color change. The formed complexes after releasing the solvent were investigated and their structures are suggested to have square planar or octahedral arrangement. Pharmacodynamic of cobalt(III) complex on some biochemical parameters and histological studies in serum and heart tissue in rats have been studied. Although the complexes demonstrated a significant effect at low dose than the high dose, the ligand showed significant good effects in both high and low doses on the biochemical analysis in serum and heart tissue. Cobalt complex was screened in order to evaluate its antifungal activity against the filamentous fungi Aspergillus niger, Aspergillus fumigatus, and Aspergillus flavus, and antibacterial activity against the Candida albicans, Escherichia coli, Klebseilla pneumoniae and Pseudomonas aeruginosa.

  18. Position-controlled III-V compound semiconductor nanowire solar cells by selective-area metal-organic vapor phase epitaxy.

    PubMed

    Fukui, Takashi; Yoshimura, Masatoshi; Nakai, Eiji; Tomioka, Katsuhiro

    2012-01-01

    We demonstrate position-controlled III-V semiconductor nanowires (NWs) by using selective-area metal-organic vapor phase epitaxy and their application to solar cells. Efficiency of 4.23% is achieved for InP core-shell NW solar cells. We form a 'flexible NW array' without a substrate, which has the advantage of saving natural resources over conventional thin film photovoltaic devices. Four junction NW solar cells with over 50% efficiency are proposed and discussed.

  19. Cotton liners to mediate glove comfort for greenhouse applicators.

    PubMed

    Stone, J; Coffman, C; Imerman, P M; Song, K; Shelley, M

    2005-10-01

    Greenhouse applicators' acceptance of cotton knit gloves worn as liners under nitrile chemical-resistant gloves (CRG) for pesticide application was investigated through a wear study in Iowa and New York. Comfort was assessed by questionnaires and interviews with 10 applicators. Contamination levels of four pesticides on CRG and liners at thumb, forefinger, palm, and cuff locations were determined by chemical analysis using high-performance liquid chromatography or gas chromatography. Applicators reported feeling more comfortable with cotton liners under their CRG than without and that cotton liners were easy to manage. Contamination was significantly greater on nitrile CRG than on cotton liners underneath, but a few liner specimens had measurable contamination. No significant contamination differences were found between right- and left-hand gloves. Contamination varied significantly by hand location, with cuffs least, and by pesticide, with chlorpyrifos most. These results support the Environmental Protection Agency's recommendation that liners should be disposable, but further work on liners and their laundering feasibility seems indicated.

  20. Development of Standardized Material Testing Protocols for Prosthetic Liners.

    PubMed

    Cagle, John C; Reinhall, Per G; Hafner, Brian J; Sanders, Joan E

    2017-04-01

    A set of protocols was created to characterize prosthetic liners across six clinically relevant material properties. Properties included compressive elasticity, shear elasticity, tensile elasticity, volumetric elasticity, coefficient of friction (CoF), and thermal conductivity. Eighteen prosthetic liners representing the diverse range of commercial products were evaluated to create test procedures that maximized repeatability, minimized error, and provided clinically meaningful results. Shear and tensile elasticity test designs were augmented with finite element analysis (FEA) to optimize specimen geometries. Results showed that because of the wide range of available liner products, the compressive elasticity and tensile elasticity tests required two test maxima; samples were tested until they met either a strain-based or a stress-based maximum, whichever was reached first. The shear and tensile elasticity tests required that no cyclic conditioning be conducted because of limited endurance of the mounting adhesive with some liner materials. The coefficient of friction test was based on dynamic coefficient of friction, as it proved to be a more reliable measurement than static coefficient of friction. The volumetric elasticity test required that air be released beneath samples in the test chamber before testing. The thermal conductivity test best reflected the clinical environment when thermal grease was omitted and when liner samples were placed under pressure consistent with load bearing conditions. The developed procedures provide a standardized approach for evaluating liner products in the prosthetics industry. Test results can be used to improve clinical selection of liners for individual patients and guide development of new liner products.

  1. 49 CFR 193.2187 - Nonmetallic membrane liner.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Design Lng Storage Tanks § 193.2187 Nonmetallic membrane liner. A flammable nonmetallic membrane liner may not be used as an inner container in a storage tank....

  2. 49 CFR 193.2187 - Nonmetallic membrane liner.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Design Lng Storage Tanks § 193.2187 Nonmetallic membrane liner. A flammable nonmetallic membrane liner may not be used as an inner container in a storage...

  3. 49 CFR 193.2187 - Nonmetallic membrane liner.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Design Lng Storage Tanks § 193.2187 Nonmetallic membrane liner. A flammable nonmetallic membrane liner may not be used as an inner container in a storage tank....

  4. 49 CFR 193.2187 - Nonmetallic membrane liner.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Design Lng Storage Tanks § 193.2187 Nonmetallic membrane liner. A flammable nonmetallic membrane liner may not be used as an inner container in a storage tank....

  5. 49 CFR 193.2187 - Nonmetallic membrane liner.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Design Lng Storage Tanks § 193.2187 Nonmetallic membrane liner. A flammable nonmetallic membrane liner may not be used as an inner container in a storage tank....

  6. Verification of a variable rate sprayer for nursery liner applications

    USDA-ARS?s Scientific Manuscript database

    An experimental variable-rate sprayer designed for liner applications was tested by comparing its spray deposit and coverage, and droplet density inside canopies of six nursery liner varieties with constant-rate applications. Spray samplers, including water sensitive papers (WSP) and nylon screens, ...

  7. Optimal Spray Application Rates for Ornamental Nursery Liner Production

    USDA-ARS?s Scientific Manuscript database

    Spray deposition and coverage at different application rates for nursery liners of different sizes were investigated to determine the optimal spray application rates. Experiments were conducted on two and three-year old red maple liners. A traditional hydraulic sprayer with vertical booms was used t...

  8. CONSTRUCTION, MONITORING, AND PERFORMANCE OF TWO SOIL LINERS

    EPA Science Inventory

    A prototype soil liner and a field-scale soil liner were constructed to test whether compacted soil barrier systems could be built to meet the standard set by the U.S. Environmental Protection Agency (EPA) for saturated hydraulic conductivity (< 1 x 10'7 cm/s). In situ ponded inf...

  9. 21 CFR 872.3250 - Calcium hydroxide cavity liner.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a) Identification. A calcium hydroxide cavity liner is a device material intended to be applied to the interior of a prepared cavity before insertion of restorative material, such as amalgam, to protect the pulp of a tooth...

  10. Conceptual design for high mass imploding liner experiments

    SciTech Connect

    Reinovsky, R.E.; Clark, D.A.; Ekdahl, C.A.

    1996-12-31

    We have summarized some of the motivation behind high energy liner experiments. We have identified the 100-cm-diameter Disk Explosive-Magnetic Gene promising candidate for powering such experiments and described a phenomenological modeling approach used to understand the limits of DEMG operation. We have explored the liner implosion parameter space that can be addressed by such systems and have selected a design point from which to develop a conceptual experiment. We have applied the phenomenological model to the point design parameters and used 1 D MHD tools to assess the behavior of the liner for parameters at the design point. We have not to optimized the choice of pulse power or liner parameters. We conclude that operating in the velocity range of 10-20 km/s, kinetic energies around 100 MJ are practical with currents approaching 200 MA in the liner. Higher velocities (up to almost 40 km/s) are achieved on the inner surface of a thick liner when the liner collapses to I -cm radius. At 6-cm radius the non- optimized liners explored here are attractive drivers for experiments exploring the compression of magnetized plasmas and at 1 cm they are equally attractive drivers for shock wave experiments in the pressure range of 30-100 Mbar. An experiment based on this design concept is scheduled to be conducted in VNIIEF in August 1996.

  11. ONERA-NASA Cooperative Effort on Liner Impedance Eduction

    NASA Technical Reports Server (NTRS)

    Primus, Julien; Piot, Estelle; Simon, Frank; Jones, Michael G.; Watson, Willie R

    2013-01-01

    As part of a cooperation between ONERA and NASA, the liner impedance eduction methods developed by the two research centers are compared. The NASA technique relies on an objective function built on acoustic pressure measurements located on the wall opposite the test liner, and the propagation code solves the convected Helmholtz equation in uniform ow using a finite element method that implements a continuous Galerkin discretization. The ONERA method uses an objective function based either on wall acoustic pressure or on acoustic velocity acquired above the liner by Laser Doppler Anemometry, and the propagation code solves the linearized Euler equations by a discontinuous Galerkin discretization. Two acoustic liners are tested in both ONERA and NASA ow ducts and the measured data are treated with the corresponding impedance eduction method. The first liner is a wire mesh facesheet mounted onto a honeycomb core, designed to be linear with respect to incident sound pressure level and to grazing ow velocity. The second one is a conventional, nonlinear, perforate-over-honeycomb single layer liner. Configurations without and with ow are considered. For the nonlinear liner, the comparison of liner impedance educed by NASA and ONERA shows a sensitivity to the experimental conditions, namely to the nature of the source and to the sample width.

  12. CONSTRUCTION, MONITORING, AND PERFORMANCE OF TWO SOIL LINERS

    EPA Science Inventory

    A prototype soil liner and a field-scale soil liner were constructed to test whether compacted soil barrier systems could be built to meet the standard set by the U.S. Environmental Protection Agency (EPA) for saturated hydraulic conductivity (< 1 x 10'7 cm/s). In situ ponded inf...

  13. Development of a Multifidelity Approach to Acoustic Liner Impedance Eduction

    NASA Technical Reports Server (NTRS)

    Nark, Douglas M.; Jones, Michael G.

    2017-01-01

    The use of acoustic liners has proven to be extremely effective in reducing aircraft engine fan noise transmission/radiation. However, the introduction of advanced fan designs and shorter engine nacelles has highlighted a need for novel acoustic liner designs that provide increased fan noise reduction over a broader frequency range. To achieve aggressive noise reduction goals, advanced broadband liner designs, such as zone liners and variable impedance liners, will likely depart from conventional uniform impedance configurations. Therefore, educing the impedance of these axial- and/or spanwise-variable impedance liners will require models that account for three-dimensional effects, thereby increasing computational expense. Thus, it would seem advantageous to investigate the use of multifidelity modeling approaches to impedance eduction for these advanced designs. This paper describes an extension of the use of the CDUCT-LaRC code to acoustic liner impedance eduction. The proposed approach is applied to a hardwall insert and conventional liner using simulated data. Educed values compare well with those educed using two extensively tested and validated approaches. The results are very promising and provide justification to further pursue the complementary use of CDUCT-LaRC with the currently used finite element codes to increase the efficiency of the eduction process for configurations involving three-dimensional effects.

  14. Energetics and Dynamics of Electron Transfer and Proton Transfer in Dissociation of Metal III (salen)-Peptide Complexes in the Gas Phase

    SciTech Connect

    Laskin, Julia; Yang, Zhibo; Chu, Ivan K.

    2008-03-12

    Time- and collision energy-resolved surface-induced dissociation (SID) of ternary complexes of CoIII(salen)+, FeIII(salen)+, and MnIII(salen)+ with several angiotensin peptide analogs was studied using a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) specially equipped to perform SID experiments. Time-resolved fragmentation efficiency curves (TFECs) were modeled using an RRKM-based approach developed in our laboratory. The approach utilizes a very flexible analytical expression for the internal energy deposition function that is capable of reproducing both single-collision and multiple-collision activation in the gas phase and excitation by collisions with a surface. The energetics and dynamics of competing dissociation pathways obtained from the modeling provides important insight on the competition between proton transfer, electron transfer, loss of neutral peptide ligand, and other processes that determine gas-phase fragmentation of these model systems. Similar fragmentation behavior was obtained for various CoIII(salen)-peptide systems of different angiotensin analogs. In contrast, dissociation pathways and relative stabilities of the complexes changed dramatically when cobalt was replaced with trivalent iron or manganese. We demonstrate that the electron transfer efficiency is correlated with redox properties of the metalIII(salen) complexes (Co > Fe > Mn), while differences in the types of fragments formed from the complexes reflect differences in the modes of binding between the metal-salen complex and the peptide ligand. RRKM modeling of time- and collision energy-resolved SID data suggests that the competition between proton transfer and electron transfer during dissociation of CoIII(salen)-peptide complexes is mainly determined by differences in entropy effects while the energetics of these two pathways are very similar.

  15. Chiroptical Spectra of Tetrakis (+)-3-Heptafluorobutylrylcamphorate Ln(III) Complexes with an Encapsulated Alkali Metal Ion: Solution Structures as Revealed by Chiroptical Spectra

    PubMed Central

    Shirotani, Dai; Yamanari, Kazuaki; Kuroda, Reiko; Harada, Takunori; Lunkley, Jamie L.; Muller, Gilles; Sato, Hisako; Kaizaki, Sumio

    2012-01-01

    The preparation of tetrakis((+)-hfbc) lanthanide(III) complexes with an encapsulated alkali metal and ammonium ions M[Ln((+)-hfbc)4] (hereafter abbreviated as M-Ln : (+)-hfbc, (+)-heptafluorobutyrylcamphorate; M, ammonium or benzyl ammonium ions as well as alkali metal ions) was reported and discussed. The electronic circular dichroism (CD) spectra in the intraligand π–π* transition of M–Ln were examined in view of the solvent effect. Here, the concentration, alkali metal, and ammonium ion dependences are compared with the solid CD, 5D0 ← 7F0(Eu(III)) excitation spectra, circularly polarized luminescence, and vibrational circular dichroism. It has been revealed that the dodecahedral eight coordinate DD-8-M-Ln complexes in crystals are equilibrated between the diastereoselectively formed square antiprism eight coordinate SAPR-8-M-Ln and [Ln((+)-hfbc)3] in EtOH and CH3CN solutions or between the SAPR-8-M-Ln and DD-D2d(mmmm)-8-M-Ln complexes in CHCl3 solution. The observed CD couplets are found to reflect the exciton CD couplets which are useful to determine the four-bladed SAPR-(llll) absolute configuration around the lanthanide(III) ion. PMID:22945448

  16. Metal Reduction and Mineral formation by a Psychrotolerant Fe(III)-Reducing Bacterium Isolated from an Iron-Rich Waters near a Hydrothermal Vent

    NASA Astrophysics Data System (ADS)

    Roh, Y.; Vali, H.; Stapleton, R. D.; Fields, M. M.; Phelps, T. J.; Zhou, J.

    2002-12-01

    Although dissimilatory metal reduction and mineral formation under mesophilic and thermophilic conditions are extensively examined, they are poorly understood under low temperature. The objective of this study was to examine metal reduction and mineral formation using a psychrotolerant iron-reducing bacterium (Shewanella alga, PV-4) isolated from iron-rich waters associated with the Naha vents off the Hawaiian coast. The psychrotolerant iron-reducing bacterium was able to use lactate, formate, and hydrogen as an electron donor while reducing Fe(III)-citrate, Fe(III)-EDTA, Co(III)-EDTA, Cr(VI), Mn(IV), and iron oxyhydroxide (FeOOH) at temperatures between 0 and 37°C. The psychrotolerant bacterium exhibited diverse mineral precipitation capabilities including the formation of magnetite (Fe3O4), siderite (FeCO3), and rhodochrosite (MnCO3). Transmission electron microscopic data showed that PV-4 formed mainly superparamagnetic magnetite at temperatures ranging from 0 to 14°C and formed mainly single-domain magnetite at temperatures ranging from 18 to 37°C. This study indicats that iron-reducing bacteria may contribute to the biogeochemical cycling of metals and carbon at low temperatures and may contribute to the natural remnant magnetism of marine sediments.

  17. Chiroptical spectra of tetrakis (+)-3-heptafluorobutylrylcamphorate Ln(III) complexes with an encapsulated alkali metal ion: solution structures as revealed by chiroptical spectra.

    PubMed

    Shirotani, Dai; Yamanari, Kazuaki; Kuroda, Reiko; Harada, Takunori; Lunkley, Jamie L; Muller, Gilles; Sato, Hisako; Kaizaki, Sumio

    2012-12-01

    The preparation of tetrakis((+)-hfbc) lanthanide(III) complexes with an encapsulated alkali metal and ammonium ions M[Ln((+)-hfbc)(4)] (hereafter abbreviated as M-Ln : (+)-hfbc, (+)-heptafluorobutyrylcamphorate; M, ammonium or benzyl ammonium ions as well as alkali metal ions) was reported and discussed. The electronic circular dichroism (CD) spectra in the intraligand π-π* transition of M-Ln were examined in view of the solvent effect. Here, the concentration, alkali metal, and ammonium ion dependences are compared with the solid CD, (5)D(0)←(7)F(0) (Eu(III)) excitation spectra, circularly polarized luminescence, and vibrational circular dichroism. It has been revealed that the dodecahedral eight coordinate DD-8-M-Ln complexes in crystals are equilibrated between the diastereoselectively formed square antiprism eight coordinate SAPR-8-M-Ln and [Ln((+)-hfbc)(3)] in EtOH and CH(3) CN solutions or between the SAPR-8-M-Ln and DD-D(2d) (mmmm)-8-M-Ln complexes in CHCl(3) solution. The observed CD couplets are found to reflect the exciton CD couplets which are useful to determine the four-bladed SAPR-(llll) absolute configuration around the lanthanide(III) ion. Copyright © 2012 Wiley Periodicals, Inc.

  18. Method of melting metals to reduce contamination from crucibles

    DOEpatents

    Banker, John G.; Wigginton, Hubert L.

    1977-01-01

    Contamination of metals from crucible materials during melting operations is reduced by coating the interior surface of the crucible with a ceramic non-reactive with the metallic charge and disposing a metal liner formed from a portion of the metallic charge within the coated crucible. The liner protects the ceramic coating during loading of the remainder of the charge and expands against the ceramic coating during heat-up to aid in sintering the coating.

  19. Frequency and Time Domain Modeling of Acoustic Liner Boundary Conditions

    NASA Technical Reports Server (NTRS)

    Bliss, Donald B.

    1982-01-01

    As part of a research program directed at the acoustics of advanced subsonic propulsion systems undertaken at NASA Langley, Duke University was funded to develop a boundary condition model for bulk-reacting nacelle liners. The overall objective of the Langley program was to understand and predict noise from advanced subsonic transport engines and to develop related noise control technology. The overall technical areas included: fan and propeller source noise, acoustics of ducts and duct liners, interior noise, subjective acoustics, and systems noise prediction. The Duke effort was directed toward duct liner acoustics for the development of analytical methods to characterize liner behavior in both frequency domain and time domain. A review of duct acoustics and liner technology can be found in Reference [1]. At that time, NASA Langley was investigating the propulsion concept of an advanced ducted fan, with a large diameter housed inside a relatively short duct. Fan diameters in excess of ten feet were proposed. The lengths of both the inlet and exhaust portions of the duct were to be short, probably less than half the fan diameter. The nacelle itself would be relatively thin-walled for reasons of aerodynamic efficiency. The blade-passage frequency was expected to be less than I kHz, and very likely in the 200 to 300 Hz range. Because of the design constraints of a short duct, a thin nacelle, and long acoustic wavelengths, the application of effective liner technology would be especially challenging. One of the needs of the NASA Langley program was the capability to accurately and efficiently predict the behavior of the acoustic liner. The traditional point impedance method was not an adequate model for proposed liner designs. The method was too restrictive to represent bulk reacting liners and to allow for the characterization of many possible innovative liner concepts. In the research effort at Duke, an alternative method, initially developed to handle bulk

  20. Copper adsorption with Pb and Cd in sand-bentonite liners under various pHs. Part II. Effect on adsorption sites.

    PubMed

    Kaoser, Saleh; Barrington, Suzelle; Elektorowicz, Maria; Wang, Li

    2004-01-01

    The project examined the effect of Pb and Cd on Cu adsorption using sand liners containing 0, 5, and 10% sodium bentonite and exposed to metal solutions at three pH levels (3.7, 5.5, and 7.5). Aliquots of 2 g of liner material were exposed in duplicate, for 14 days, to solutions containing Cu alone or Cu with either Pb or Cd. Selective sequential extraction (SSE) was used to quantity the Cu adsorbed by each liner particle adsorption site (exchangeable, carbonate and hydroxide, oxides and residual). The results indicated that two main factors affected liner material behavior in adsorbing Cu, besides Cd and Pb competition: pH either above or below 6.5; liner cation exchange capacity (CEC) greater or equal and greater than the solution cation equivalence. In general, the liner carbonate and hydroxide fractions precipitated the greatest amount of Cu, under all environmental conditions while the exchangeable, oxide and residual adsorbed more or less the same amount. Lead, and to a lesser extent Cd, significantly increase the mobility of Cu, by competing especially for the exchangeable sites. While Cd also competed against Cu for oxide adsorption, Pb competes for calcium and hydroxide precipitation. Lead, and to a lesser extent Cd, competed especially for the exchangeable site where the adsorption is more dynamic, and less for the more permanent adsorption sites, involving precipitation, and electrostatic bonding.

  1. Theoretical study of metal-ligand interaction in Sm(III), Eu(III), and Tb(III) complexes of coumarin-3-carboxylic acid in the gas phase and solution.

    PubMed

    Georgieva, Ivelina; Trendafilova, Natasha; Aquino, Adélia J A; Lischka, Hans

    2007-12-10

    The interaction of lanthanide(III) cations (Ln(III) = Sm(III), Eu(III), and Tb(III)) with the deprotonated form of the coumarin-3-carboxylic acid (cca-) has been investigated by density functional theory (DFT/B3LYP) and confirmed by reference MP2 and CCSD(T) computations. Solvent effects on the geometries and stabilities of the Ln(III) complexes were computed using a combination of water clusters and a continuum solvation model. The following two series of systems were considered: (i) Ln(cca)2+, Ln(cca)2+, Ln(cca)3 and (ii) Ln(cca)(H2O)2Cl2, Ln(cca)2(H2O)2Cl, Ln(cca)3. The strength and character of the Ln(III)-cca- bidentate bonding were characterized by calculated Ln-O bond lengths, binding energies, ligand deformation energies, energy partitioning analysis, sigma-donation contributions, and natural population analyses. The energy decomposition calculations predicted predominant electrostatic interaction terms to the Ln-cca bonding (ionic character) and showed variations of the orbital interaction term (covalent contributions) for the Ln-cca complexes studied. Electron distribution analysis suggested that the covalent contribution comes mainly from the interaction with the carboxylate moiety of cca-.

  2. Modular liquid-cooled helmet liner for thermal comfort

    NASA Technical Reports Server (NTRS)

    Williams, B. A.; Shitzer, A.

    1974-01-01

    A modular liquid-cooled helmet liner made of eight form-fitting neoprene patches was constructed. The liner was integrated into the sweatband of an Army SPH-4 helicopter aircrew helmet. This assembly was tested on four subjects seated in a hot (47 C), humid (40%) environment. Results indicate a marked reduction in the rate of increase of physiological body functions. Rectal temperature, weight loss, heart rate, and strain indices are all reduced to approximately 50% of uncooled levels. The cooling liner removed from 10% to 30% of total metabolic heat produced. This study also demonstrated the technical feasilibity of using a cooling liner in conjunction with a standard hard helmet. Potential applications of the cooling liner in thermally stressful environments are numerous, notably for helicopter and other aircrews.

  3. Nondestructive evaluation of environmental barrier coatings in CFCC combustor liners.

    SciTech Connect

    Sun, J. G.; Benz, J.; Ellingson, W. A.; Kimmel, J. B.; Price, J. R.; Energy Technology; Solar Turbines, Inc

    2007-01-01

    Advanced combustor liners fabricated of SiC/SiC continuous fiber-reinforced ceramic composite (CFCC) and covered with environmental barrier coatings (EBCs) have been successfully tested in Solar Turbines Inc. field engines. The primary goal for the CFCC/EBC liners is to reach a 30,000-h lifetime. Because the EBCs, when applied on the hot surfaces of liners, protect the underlying CFCC from oxidation damage, their performance is critical in achieving the lifetime goal. To determine CFCC/EBC liner condition and assess operating damage, the liners were subjected to nondestructive evaluation (NDE) during various processing stages, as well as before and after the engine test. The NDE techniques included pulsed infrared thermal imaging, air-coupled ultrasonic scanning, and X-ray computerized tomography. It was found that EBC damage and spallation depend on the condition of the CFCC material. The NDE results and correlations with destructive examination are discussed.

  4. Modular liquid-cooled helmet liner for thermal comfort

    NASA Technical Reports Server (NTRS)

    Williams, B. A.; Shitzer, A.

    1974-01-01

    A modular liquid-cooled helmet liner made of eight form-fitting neoprene patches was constructed. The liner was integrated into the sweatband of an Army SPH-4 helicopter aircrew helmet. This assembly was tested on four subjects seated in a hot (47 C), humid (40%) environment. Results indicate a marked reduction in the rate of increase of physiological body functions. Rectal temperature, weight loss, heart rate, and strain indices are all reduced to approximately 50% of uncooled levels. The cooling liner removed from 10% to 30% of total metabolic heat produced. This study also demonstrated the technical feasilibity of using a cooling liner in conjunction with a standard hard helmet. Potential applications of the cooling liner in thermally stressful environments are numerous, notably for helicopter and other aircrews.

  5. Evaluating the accuracy of wear formulae for acetabular cup liners.

    PubMed

    Wu, James Shih-Shyn; Hsu, Shu-Ling; Chen, Jian-Horng

    2010-02-01

    This study proposes two methods for exploring the wear volume of a worn liner. The first method is a numerical method, in which SolidWorks software is used to create models of the worn out regions of liners at various wear directions and depths. The second method is an experimental one, in which a machining center is used to mill polyoxymethylene to manufacture worn and unworn liner models, then the volumes of the models are measured. The results show that the SolidWorks software is a good tool for presenting the wear pattern and volume of a worn liner. The formula provided by Ilchmann is the most suitable for computing liner volume loss, but is not accurate enough. This study suggests that a more accurate wear formula is required. This is crucial for accurate evaluation of the performance of hip components implanted in patients, as well as for designing new hip components.

  6. IUE and Einstein observations of the LINER galaxy NGC 4579

    NASA Technical Reports Server (NTRS)

    Reichert, G. A.; Puchnarewicz, E. M.; Mason, K. O.

    1990-01-01

    Results of International Ultraviolet Explorer (IUE) and Einstein observations of the LINER galaxy NGC 4579 are reported. Spatial profiles of the long wavelength IUE emission show a two component structure, with an unresolved core superimposed on broader underlying emission. The core spectrum shows strong C II lambda 2326 and broad Mg II lambda 2800 emission, and perhaps emission due to blends of Fe II multiplets (2300 to 23600 angstrom). The short wavelength emission is spatially unresolved, and shows C II lambda 1335, C III lambda 1909 broad C IV lambda 1550 emission, and a broad feature at approximately 1360 angstrom which may be due to 0.1 lambda 1356. Contrary to previous reports no evidence for He II lambda 1640 is found in the spectrum. An unresolved x ray source is detected at the location of the nucleus; its spectrum is well fitted by a power law of energy slope alpha approximately -0.5. These results further support the idea that NGC 4579 may contain a dwarf Seyfert nucleus.

  7. High energy imploding liner experiment HEL-1: Experimental results

    SciTech Connect

    Clark, D.A.; Anderson, B.G.; Ekdahl, C.A.

    1997-09-01

    Magnetically driven imploding liner systems can be used as a source of shock energy for materials equation of state studies, implosion driven magnetized plasma fusion experiments, and other similar applications. The imploding liner is a cylinder of conducting material through which a current is passed in the longitudinal direction. Interaction of the current with its own magnetic field causes the liner to implode. Sources of electrical energy for imploding liner systems are capacitor banks or explosive pulse power systems seeded by capacitor banks. In August, 1996, a high energy liner experiment (HEL-1) was conducted at the All-Russia Scientific Research Institute (VNIIEF) in Sarov, Russia. A 5 tier 1 meter diameter explosive disk generator provided electrical energy to drive a 48 cm outside diameter, 4 mm thick, aluminum alloy liner having a mass of about 11kg onto an 11 cm diameter diagnostic package. The purpose of the experiment was to measure performance of the explosive pulse power generator and the heavy imploding liner. Electrical performance diagnostics included inductive (B-dot) probes, Faraday Rotation current measurement, Rogowski total current measurement, and voltage probes. Flux loss and conductor motion diagnostics included current-joint voltage measurements and motion sensing contact pins. Optical and electrical impact pins, inductive (B-dot) probes, manganin pressure probes, and continuously recording resistance probes in the Central Measuring Unit (CMU) and Piezo and manganin pressure probes, optical beam breakers, and inductive probes located in the glide planes were used as liner symmetry and velocity diagnostics. Preliminary analysis of the data indicate that a peak current of more than 100 MA was attained and the liner velocity was between 6.7 km/sec and 7.5 km/sec. Liner kinetic energy was between 22 MJ and 35 MJ. 4 refs., 6 figs., 1 tab.

  8. User experience of transtibial prosthetic liners: A systematic review.

    PubMed

    Richardson, Amy; Dillon, Michael P

    2017-02-01

    The liner is an integral part of a transtibial prosthesis designed to protect the residual limb, enhance comfort and provide suspension. Literature is difficult to interpret and use given the variety of interventions, outcome measures and method designs. Critical appraisal and synthesis of the evidence is needed to help inform decisions about liner prescription based on the user experience. To critically appraise and synthesise research describing the user experience of transtibial prosthetic liners. Systematic review. A comprehensive suite of databases were searched using terms related to amputation level, liner type and user experience. Included studies were in English and measured the first-person experience of using a transtibial liner. Studies were appraised using the McMaster University Critical Review Forms. A total of 18 articles met the inclusion criteria. While the quality of the evidence has improved over time, a number of common issues (e.g. sampling bias, validity of outcome measures, incorrect inferential analysis) reduce our ability to differentiate between the user experience of different transtibial liners. There is insufficient research to differentiate between the user experience of different transtibial liners. High-quality research is needed to inform decisions about liner prescription based on the user experience. Clinical relevance The available evidence suggests that the user experience of commonly reported problems (e.g. sweating) may be very similar between different liners. Aspects of the user experience that differ most between liners (e.g. unwanted noises, rotation within the socket) can help focus attention on what matters most when discussing prescription.

  9. Laboratory measurements of contaminant attenuation of uranium mill tailings leachates by sediments and clay liners

    SciTech Connect

    Serne, R.J.; Peterson, S.R.; Gee, G.W.

    1983-04-01

    We discuss FY82 progress on the development of laboratory tools to aid in the prediction of migration potential of contaminants present in acidic uranium mill tailings leachate. Further, empirical data on trace metal and radionuclide migration through a clay liner are presented. Acidic uranium mill tailings solution from a Wyoming mill was percolated through a composite sediment called Morton Ranch Clay liner. These laboratory columns and subsequent sediment extraction data show: (1) As, Cr, Pb, Ag, Th and V migrate very slowly; (2) U, Cd, Ni, Zn, Fe, Mn and similar transition metals are initially immobilized during acid neutralization but later are remobilized as the tailings solution exhausts the clay liner's acid buffering capacity. Such metals remain immobilized as long as the effluent pH remains above a pH value of 4 to 4.5, but they become mobile once the effluent pH drops below this range; and (3) fractions of the Se and Mo present in the influent tailings solution are very mobile. Possible controlling mechanisms for the pH-dependent immobilization-mobilization of the trace metals are discussed. More study is required to understand the controlling mechanisms for Se and Mo and Ra for which data were not successfully collected. Using several column lengths (from 4.5 to 65 cm) and pore volume residence times (from 0.8 to 40 days) we found no significant differences in contaminant migration rates or types and extent of controlling processes. Thus, we conclude that the laboratory results may be capable of extrapolation to actual disposal site conditions.

  10. Collaborative Research and Development (CR&D) III Task Order 0077: Fundamental Studies of Plasticity, Interfacial Boundaries and Liquid Metals

    DTIC Science & Technology

    2013-06-01

    2 2.1 Thermally-Activated Slip in HCP and BCC Metals ......................................................2 2.2 Lattice Green Function...4 3.1 Thermally-Activated Slip in HCP and BCC Metals ......................................................4 3.2 Lattice...5 4.1 Thermally-activated Slip in HCP and BCC Metals

  11. Sorption characteristics and chromatographic separation of gold (I and III) from silver and base metal ions using polyurethane foams.

    PubMed

    Farag, A B; Soliman, M H; Abdel-Rasoul, O S; el-Shahawi, M S

    2007-10-10

    tap- and industrial wastewater samples at <10 microg Au mL(-1) after reduction to gold (I). The IEPUFs packed column was applied satisfactorily for complete retention and recovery (98.5+/-2.7) of total inorganic gold (I) and/or gold (III) species spiked to tap- and industrial wastewater samples at <10 microg mL(-1) gold. Chromatographic separation of gold (I) from silver (I) and base metal ions (Fe, Ni, Cu and Zn) using IEPUFS packed columns was satisfactorily achieved. The proposed method was applied successfully for the pre-concentration and separation from anodic slime and subsequent FAAS determination of analyte with satisfactory results (recoveries >95%, relative standard deviations <4.0%).

  12. Feasibility study of III-nitride-based transistors grown by ammonia-based metal-organic molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Billingsley, Daniel D.

    Although commercially available high-electron mobility transistors (HEMTs) based on the III-Nitride material system are available, there still remains areas for further optimization. These transistor devices are currently limited because of current leakage when the devices are operated at increased operating voltages. To reach the full potential of these devices, these leakage mechanisms need to be addressed. The objective of this work is to utilize the highly resistive properties of carbon-doped gallium nitride (GaN) as a low-leakage buffer layer for HEMTs. By increasing the resistivity of the underlying GaN layer, the source-drain current flow will be limited to electrons in the two-dimensional electron gas (2DEG) confined to the interface, reducing leakage paths through the GaN buffer layer, ultimately increasing the power density of the device. These films are deposited via a novel ammonia-based metal-organic molecular beam epitaxy (NH3-MOMBE) system capable of producing unintentionally carbon-doped GaN films with carbon concentrations ([C]) in excess of 10 21 atoms/cm3. These high levels of carbon incorporation lead to highly-resistive GaN buffer layers with a resistivity estimated at ˜10 12 O-cm. In addition, the deposition of aluminum gallium nitride (AlGaN) has been accomplished for the first time in an NH3-MOMBE environment. The AlGaN alloy is necessary for the production of a 2DEG, which is the source of electrons for the operation of the transistor. While providing the ability to produce highly-resistive buffer layers, the carbon which is unintentionally incorporated during the deposition of the films may also become a source of channel depletion if the incorporation levels cannot be controlled. The results of this work demonstrate that carbon-doped NH3-MOMBE thin films are extremely resistive, yet further optimization is necessary for the realization of transistor devices because of the trap states that are produced from the excessive carbon

  13. Thermographic inspection of pipes, tanks, and containment liners

    SciTech Connect

    Renshaw, Jeremy B. Muthu, Nathan; Lhota, James R.; Shepard, Steven M.

    2015-03-31

    Nuclear power plants are required to operate at a high level of safety. Recent industry and license renewal commitments aim to further increase safety by requiring the inspection of components that have not traditionally undergone detailed inspected in the past, such as tanks and liners. NEI 09-14 requires the inspection of buried pipes and tanks while containment liner inspections are required as a part of license renewal commitments. Containment liner inspections must inspect the carbon steel liner for defects - such as corrosion - that could threaten the pressure boundary and ideally, should be able to inspect the surrounding concrete for foreign material that could be in contact with the steel liner and potentially initiate corrosion. Such an inspection requires a simultaneous evaluation of two materials with very different material properties. Rapid, yet detailed, inspection results are required due to the massive size of the tanks and containment liners to be inspected. For this reason, thermal NDE methods were evaluated to inspect tank and containment liner mockups with simulated defects. Thermographic Signal Reconstruction (TSR) was utilized to enhance the images and provide detailed information on the sizes and shapes of the observed defects. The results show that thermographic inspection is highly sensitive to the defects of interest and is capable of rapidly inspecting large areas.

  14. Wear of a sequentially annealed polyethylene acetabular liner

    PubMed Central

    Gascoyne, Trevor C; Petrak, Martin J; Turgeon, Thomas R; Bohm, Eric R

    2014-01-01

    Background and purpose We previously reported on a randomized controlled trial (RCT) that examined the effect of adding tobramycin to bone cement after femoral stem migration. The present study examined femoral head penetration into both conventional and highly crosslinked polyethylene acetabular liners in the same group of RCT patients, with a minimum of 5 years of postoperative follow-up. Patients and methods Linear penetration of the femoral head into an X3 (Stryker) crosslinked polyethylene (XLPE) liner was measured in 18 patients (19 hips) using radiostereometric analysis (RSA). Femoral head penetration was also measured in 6 patients (6 hips) with a conventional polyethylene liner (CPE), which served as a control group. Results The median proximal femoral head penetration in the XLPE group after 5.5 years was 0.025 mm with a steady-state penetration rate of 0.001 mm/year between year 1 and year 5. The CPE liner showed a median proximal head penetration of 0.274 mm after 7.2 years, at a rate of 0.037 mm/year. Interpretation The Trident X3 sequentially annealed XLPE liner shows excellent in vivo wear resistance compared to non-crosslinked CPE liners at medium-term implantation. The rate of linear head penetration in the XLPE liners after > 5 years of follow-up was 0.001 mm/year, which is in close agreement with the results of previous studies. PMID:25140986

  15. Two-dimensional modeling of magnetically imploded liners

    SciTech Connect

    Atchison, W.L.; Bowers, R.L.; Brownell, J.H.; Lee, H.

    1996-11-01

    Magnetically imploded massive cylindrical liner drivers have been studied in two-dimensions for low, intermediate and high energy pulsed power systems. The simulations have been carried out using a resistive Eulerian magnetohydrodynamics computational model which includes material strength, and models the interactions between the imploding liner and the electrode walls. The computations simulate the generation of perturbations and their subsequent growth during the implosion. At low energies a solid liner remains in the plastic regime, reaching an inner cylindrical target with velocities of a few mm per {mu}s. At higher energies (where one-dimensional models predict implosion velocities of order 1 cm/{mu}s or more) resistive heating of the liner results in melting, and the effects of magnetically driven instabilities become important. We discuss the two-dimensional issues which arise in these systems. These include: the onset of perturbations associated with the motion of the liner along the electrodes; the growth of instabilities in liquid layers; and the suppression of instability growth during the implosion by maintaining a solid inner layer. Studies have been made of liners designed for the Pegasus capacitor bank facility (currents in the 5 - 12 MA regime), and for the Procyon high explosive system (currents in the 20 MA regime). This work focus on the design and performance of the first Pegasus composite megabar liner experiment.

  16. Further Development and Assessment of a Broadband Liner Optimization Process

    NASA Technical Reports Server (NTRS)

    Nark, Douglas M.; Jones, Michael G.; Sutliff, Daniel L.

    2016-01-01

    The utilization of advanced fan designs (including higher bypass ratios) and shorter engine nacelles has highlighted a need for increased fan noise reduction over a broader frequency range. Thus, improved broadband liner designs must account for these constraints and, where applicable, take advantage of advanced manufacturing techniques that have opened new possibilities for novel configurations. This work focuses on the use of an established broadband acoustic liner optimization process to design a variable-depth, multi-degree of freedom liner for a high speed fan. Specifically, in-duct attenuation predictions with a statistical source model are used to obtain optimum impedance spectra over the conditions of interest. The predicted optimum impedance information is then used with acoustic liner modeling tools to design a liner aimed at producing impedance spectra that most closely match the predicted optimum values. The multi-degree of freedom design is carried through design, fabrication, and testing. In-duct attenuation predictions compare well with measured data and the multi-degree of freedom liner is shown to outperform a more conventional liner over a range of flow conditions. These promising results provide further confidence in the design tool, as well as the enhancements made to the overall design process.

  17. Thermographic inspection of pipes, tanks, and containment liners

    NASA Astrophysics Data System (ADS)

    Renshaw, Jeremy B.; Lhota, James R.; Muthu, Nathan; Shepard, Steven M.

    2015-03-01

    Nuclear power plants are required to operate at a high level of safety. Recent industry and license renewal commitments aim to further increase safety by requiring the inspection of components that have not traditionally undergone detailed inspected in the past, such as tanks and liners. NEI 09-14 requires the inspection of buried pipes and tanks while containment liner inspections are required as a part of license renewal commitments. Containment liner inspections must inspect the carbon steel liner for defects - such as corrosion - that could threaten the pressure boundary and ideally, should be able to inspect the surrounding concrete for foreign material that could be in contact with the steel liner and potentially initiate corrosion. Such an inspection requires a simultaneous evaluation of two materials with very different material properties. Rapid, yet detailed, inspection results are required due to the massive size of the tanks and containment liners to be inspected. For this reason, thermal NDE methods were evaluated to inspect tank and containment liner mockups with simulated defects. Thermographic Signal Reconstruction (TSR) was utilized to enhance the images and provide detailed information on the sizes and shapes of the observed defects. The results show that thermographic inspection is highly sensitive to the defects of interest and is capable of rapidly inspecting large areas.

  18. Nondestructive test to track pollutant transport into landfill liners

    NASA Astrophysics Data System (ADS)

    Bezzar, A.; Ghomari, F.

    2009-03-01

    Over the last decade, waste disposal has become a particularly sensitive issue in Algeria. New legislation concerning landfill liner design has been adopted. Traditional methods of landfill liner characterization involve soil sampling and chemical analysis, which are costly, destructive and time-consuming. New techniques are currently being investigated that aim to provide nondestructive liner characterisation. This paper details technical aspects associated with electrical conductivity measurements within landfill liners and presents experimental work to show the direct application of electrical techniques to track ionic movement through a sand bentonite liner under chemically induced flow. Samples of sand bentonite were mixed and compacted with NaCl electrolytes at different concentrations. The electrical conductivities of compacted specimens were measured with a two-electrode cell. The effects of frequency and electrolyte concentration on the conductivity measurement were explored. The relationship between the soil electrical conductivity and the NaCl electrolyte concentration in interstitial pore fluid was determined. The conductivity measurements were used to quantify the pore fluid concentration and effective diffusion coefficient of sand bentonite liners. It is concluded here that the electrical conductivity of compacted specimens depends mainly on the salt concentration in the pore fluid, and that this approach could therefore be used to track ionic movement through liners during diffusion.

  19. Retrieved highly crosslinked UHMWPE acetabular liners have similar wear damage as conventional UHMWPE.

    PubMed

    Schroder, David T; Kelly, Natalie H; Wright, Timothy M; Parks, Michael L

    2011-02-01

    Highly crosslinked UHMWPE is associated with increased wear resistance in hip simulator and clinical studies. Laboratory and case studies, however, have described rim fracture in crosslinked acetabular liners. Controversy exists, therefore, on the relative merits of crosslinked liners over conventional liners in terms of wear performance versus resistance to fatigue cracking. We asked whether crosslinked liners would show less surface damage than conventional liners but would be more susceptible to fatigue damage. We examined 36 conventional UHMWPE and 39 crosslinked UHMWPE retrieved implants with similar patient demographics and identical design for evidence of wear damage, including articular surface damage, impingement, screw-hole creep, and rim cracks. We observed no difference in wear damage scores for the two liners. Conventional liners more frequently impinged but were more often elevated with smaller head sizes. We observed creep in approximately 70% of both types of liners. Incipient rim cracks were found in five crosslinked liners, and one liner had a rim fracture. Only one conventional liner had an incipient rim crack. Contrary to our expectation, damage was similar between crosslinked and conventional UHMWPE liners. Moreover, the 15% occurrence (six of 39) of incipient or complete fractures in crosslinked liners as compared with a 3% occurrence (one of 36) in conventional liners may have implications for the long-term performance of crosslinked liners. Longer-term studies will be necessary to establish the fate of rim cracks and thus the overall clinical fatigue performance of crosslinked liners.

  20. Formed platelet combustor liner construction feasibility, phase A

    NASA Astrophysics Data System (ADS)

    Hayes, W. A.; Janke, D. E.

    1992-09-01

    Environments generated in high pressure liquid rocket engines impose severe requirements on regeneratively cooled combustor liners. Liners fabricated for use in high chamber pressures using conventional processes suffer from limitations that can impair operational cycle life and can adversely affect wall compatibility. Chamber liners fabricated using formed platelet technology provide an alternative to conventional regeneratively cooled liners (an alternative that has many attractive benefits). A formed platelet liner is made from a stacked assembly of platelets with channel features. The assembly is diffusion bonded into a flat panel and then three-dimensionally formed into a section of a chamber. Platelet technology permits the liner to have very precisely controlled and thin hot gas walls and therefore increased heat transfer efficiency. Further cooling efficiencies can be obtained through enhanced design flexibility. These advantages translate into increased cycle life and enhanced wall compatibility. The increased heat transfer efficiency can alternately be used to increase engine performance or turbopump life as a result of pressure drop reductions within the regeneratively cooled liner. Other benefits can be obtained by varying the materials of construction within the platelet liner to enhance material compatibility with operating environment or with adjoining components. Manufacturing cost savings are an additional benefit of a formed platelet liner. This is because of reduced touch labor and reduced schedule when compared to conventional methods of manufacture. The formed platelet technology is not only compatible with current state-of-the art combustion chamber structural support and manifolding schemes, it is also an enabling technology that allows the use of other high performance and potentially low cost methods of construction for the entire combustion chamber assembly. The contract under which this report is submitted contains three phases: (1) phase

  1. Formed platelet combustor liner construction feasibility, phase A

    NASA Technical Reports Server (NTRS)

    Hayes, W. A.; Janke, D. E.

    1992-01-01

    Environments generated in high pressure liquid rocket engines impose severe requirements on regeneratively cooled combustor liners. Liners fabricated for use in high chamber pressures using conventional processes suffer from limitations that can impair operational cycle life and can adversely affect wall compatibility. Chamber liners fabricated using formed platelet technology provide an alternative to conventional regeneratively cooled liners (an alternative that has many attractive benefits). A formed platelet liner is made from a stacked assembly of platelets with channel features. The assembly is diffusion bonded into a flat panel and then three-dimensionally formed into a section of a chamber. Platelet technology permits the liner to have very precisely controlled and thin hot gas walls and therefore increased heat transfer efficiency. Further cooling efficiencies can be obtained through enhanced design flexibility. These advantages translate into increased cycle life and enhanced wall compatibility. The increased heat transfer efficiency can alternately be used to increase engine performance or turbopump life as a result of pressure drop reductions within the regeneratively cooled liner. Other benefits can be obtained by varying the materials of construction within the platelet liner to enhance material compatibility with operating environment or with adjoining components. Manufacturing cost savings are an additional benefit of a formed platelet liner. This is because of reduced touch labor and reduced schedule when compared to conventional methods of manufacture. The formed platelet technology is not only compatible with current state-of-the art combustion chamber structural support and manifolding schemes, it is also an enabling technology that allows the use of other high performance and potentially low cost methods of construction for the entire combustion chamber assembly. The contract under which this report is submitted contains three phases: (1) phase

  2. A sensate liner for personnel monitoring applications

    NASA Astrophysics Data System (ADS)

    Lind, Eric J.; Jayaraman, Sundaresan; Park, Ms. Sungmee; Rajamanickam, Rangaswamy; Eisler, Robert, , Dr.; Burghart, Mr. George; McKee, Mr. Tony

    This program develops and demonstrates technologies useful for implementing a manageable cost effective systems approach to monitoring the medical condition of personnel by way of an instrumented uniform hereafter referred to as a Sensate Liner (SL). The SL consists of a form fitting garment which contains and interconnects sensing elements and devices to an electronics pack containing a processor and transmitter. The SL prototype requires fiber, textile, garment and sensor development. The SL textile consists of a mesh of electrically and optically conductive fibers integrated into the normal structure (woven or knitted) of fibers and yarns selected for comfort and durability. A suite of SL garment compatible embedded biological and physical sensors are then integrated into the SL. The initial SL sensor suite is selected to improve triage for combat casualties. Additional SL sensor concepts for medical monitoring will be discussed.

  3. A Sensate Liner for personnel monitoring applications.

    PubMed

    Lind, E J; Jayaraman, S; Park, S; Rajamanickam, R; Eisler, R; Burghart, G; McKee, T

    1998-01-01

    This program develops and demonstrates technologies useful for implementing a manageable cost effective systems approach to monitoring the medical condition of personnel by way of an instrumented uniform hereafter referred to as a Sensate Liner (SL). The SL consists of a form fitting garment which contains and interconnects sensing elements and devices to an electronics pack containing a processor and transmitter. The SL prototype requires fiber, textile, garment and sensor development. The SL textile consists of a mesh of electrically and optically conductive fibers integrated into the normal structure (woven or knitted) of fibers and yarns selected for comfort and durability. A suite of SL garment compatible embedded biological and physical sensors are then integrated into the SL. The initial SL sensor suite is selected to improve triage for combat casualties. Additional SL sensor concepts for medical monitoring will be discussed.

  4. A sensate liner for biomedical monitoring applications.

    PubMed

    Lind, E J; Jayaraman, S; Park, S; Rajamanickam, R; Eisler, R; Burghart, G; McKee, T

    1998-01-01

    This program develops and demonstrates technologies useful for implementing a manageable cost effective systems approach to monitoring the medical condition of personnel by way of an instrumented uniform hereafter referred to as a Sensate Liner (SL). The SL consists of a form fitting garment which contains and interconnects sensing elements and devices to an electronics pack containing a processor and transmitter. The SL prototype requires fiber, textile, garment and sensor development. The SL textile consists of a mesh of electrically and optically conductive fibers integrated into the normal structure (woven or knitted) of fibers and yarns selected for comfort and durability. A suite of SL garment compatible embedded biological and physical sensors are then integrated into the SL. The initial SL sensor suite is selected to improve triage for combat casualties. Additional SL sensor concepts for medical monitoring will be discussed.

  5. CANMET Gasifier Liner Coupon Material Test Plan

    SciTech Connect

    Mark Fitzsimmons; Alan Darby; Fred Widman

    2005-10-30

    The test plan detailed in this topical report supports Task 1 of the project titled ''Development of Technologies and Capabilities for Coal Energy Resources - Advanced Gasification Systems Development (AGSD)''. The purpose of these tests is to verify that materials planned for use in an advanced gasifier pilot plant will withstand the environments in a commercial gasifier. Pratt & Whitney Rocketdyne (PWR) has developed and designed the cooled liner test assembly article that will be tested at CANMET Energy Technology Centre (CETC-O) in Ottawa, Ontario, Canada (CETC-O). The Test Plan TP-00364 is duplicated in its entirety, with formatting changes to comply with the format required for this Topical Report. The table of contents has been modified to include the additional material required by this topical report. Test Request example and drawings of non-proprietary nature are also included as appendices.

  6. Pegasus liner stability experiments: Diagnostics and experimental results

    SciTech Connect

    Clark, D.A.; Morgan, D.V.; Rodriguez, G.

    1998-12-31

    A series of experiments to compare imploding cylindrical liner performance with Magneto-HydroDynamic (MHD) modeling has been performed at the Los Alamos National Laboratory Pegasus capacitor bank. Several configurations of aluminum liners have been used; some with initial perturbations and some smooth. Instability growth resulting from the perturbations has been observed with high resolution. Load diagnostics included radial x-rays, fiber optic impact pins, and VISAR (Velocity Interferometer for a Surface of Any Reflector). Diagnostic results and comparisons for several liner stability (LS) experiments are presented.

  7. Prediction of the acoustic impedance of duct liners

    NASA Technical Reports Server (NTRS)

    Zorumski, W. E.; Tester, B. J.

    1976-01-01

    Recent research which contributes to the prediction of the acoustic impedance of duct liners is reviewed. This review includes the linear and nonlinear properties of sheet and bulk type materials and methods for the measurement of these properties. It also includes the effect of grazing flow on the acoustic properties of materials. Methods for predicting the properties of single or multilayered, point reacting or extended reaction, and flat or curved liners are discussed. Based on this review, methods for predicting the properties of the duct liners which are typically used in aircraft engines are recommended. Some areas of needed research are discussed briefly.

  8. Complexation of metal ions, including alkali-earth and lanthanide(III) ions, in aqueous solution by the ligand 2,2',6',2''-terpyridyl.

    PubMed

    Hamilton, Joanna M; Anhorn, Michael J; Oscarson, Karen A; Reibenspies, Joseph H; Hancock, Robert D

    2011-04-04

    Some metal-ion-complexing properties of the ligand 2,2',6',2''-terpyridyl (terpy) in aqueous solution are determined by following the π-π* transitions of 2 × 10(-5) M terpy by UV-visible spectroscopy. It is found that terpy forms precipitates when present as the neutral ligand above pH ∼5, in the presence of electrolytes such as NaClO(4) or NaCl added to control the ionic strength, as evidenced by large light-scattering peaks. The protonation constants of terpy are thus determined at the ionic strength (μ) = 0 to avoid precipitation and found to be 4.32(3) and 3.27(3). The log K(1) values were determined for terpy with alkali-earth metal ions Mg(II), Ca(II), Sr(II), and Ba(II) and Ln(III) (Ln = lanthanide) ions La(III), Gd(III), and Lu(III) by titration of 2 × 10(-5) M free terpy at pH >5.0 with solutions of the metal ion. Log K(1)(terpy) was determined for Zn(II), Cd(II), and Pb(II) by following the competition between the metal ions and protons as a function of the pH. Complex formation for all of these metal ions was accompanied by marked sharpening of the broad π-π* transitions of free terpy, which was attributed to complex formation affecting ligand vibrations, which in the free ligand are coupled to the π-π* transitions and thus broaden them. It is shown that log K(1)(terpy) for a wide variety of metal ions correlates well with log K(1)(NH(3)) values for the metal ions. The latter include both experimental log K(1)(NH(3)) values and log K(1)(NH(3)) values predicted previously by density functional theory calculation. The structure of [Ni(terpy)(2)][Ni(CN)(4)]·CH(3)CH(2)OH·H(2)O (1) is reported as follows: triclinic, P1, a = 8.644(3) Å, b = 9.840(3) Å, c = 20.162(6) Å, α = 97.355(5)°, β = 97.100(5)°, γ = 98.606(5)°, V = 1663.8(9) Å(3), Z = 4, and final R = 0.0319. The two Ni-N bonds to the central N donors of the terpy ligands in 1 average 1.990(2) Å, while the four peripheral Ni-N bonds average 2.107(10) Å. This difference in the M

  9. Application of the Ta liner technique to produce Ca beams at INFN-Legnaro National Laboratories (INFN-LNL)

    SciTech Connect

    Galatà, A. Sattin, M.; Manzolaro, M.; Martini, D.; Facco, A.; Tinschert, K.; Spaedtke, P.; Lang, R.; Kulevoy, T.

    2014-02-15

    The ECR ion sources are able to produce a wide variety of highly charged metallic ion beams thanks to the development of different techniques (ovens, sputtering, direct insertion, metal ions from volatile compounds (MIVOC)). In the case of the ovens, the sticking of the hot vapors on the surface of the plasma chamber leads to high material consumption rates. For elements like Ca, a tantalum liner inserted inside the chamber can be used to limit this phenomenon. The modeling of temperature distribution inside the chamber with and without the liner was carried out with COMSOL-multiphysics code. Results of simulation and the comparison with experiments performed at INFN-Legnaro National Laboratories with Ca beams are discussed.

  10. Application of the Ta liner technique to produce Ca beams at INFN-Legnaro National Laboratories (INFN-LNL).

    PubMed

    Galatà, A; Sattin, M; Manzolaro, M; Martini, D; Facco, A; Tinschert, K; Spaedtke, P; Lang, R; Kulevoy, T

    2014-02-01

    The ECR ion sources are able to produce a wide variety of highly charged metallic ion beams thanks to the development of different techniques (ovens, sputtering, direct insertion, metal ions from volatile compounds (MIVOC)). In the case of the ovens, the sticking of the hot vapors on the surface of the plasma chamber leads to high material consumption rates. For elements like Ca, a tantalum liner inserted inside the chamber can be used to limit this phenomenon. The modeling of temperature distribution inside the chamber with and without the liner was carried out with COMSOL-multiphysics code. Results of simulation and the comparison with experiments performed at INFN-Legnaro National Laboratories with Ca beams are discussed.

  11. Magnetized Target Fusion Driven by Plasma Liners

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Kirkpatrick, Ronald C.; Knapp, Charles E.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Magnetized target fusion is an emerging, relatively unexplored approach to fusion for electrical power and propulsion application. The physical principles of the concept are founded upon both inertial confinement fusion (ICF) and magnetic confinement fusion (MCF). It attempts to combine the favorable attributes of both these orthogonal approaches to fusion, but at the same time, avoiding the extreme technical challenges of both by exploiting a fusion regime intermediate between them. It uses a material liner to compress, heat and contain the fusion reacting plasma (the target plasma) mentally. By doing so, the fusion burn could be made to occur at plasma densities as high as six orders of magnitude higher than conventional MCF such as tokamak, thus leading to an approximately three orders of magnitude reduction in the plasma energy required for ignition. It also uses a transient magnetic field, compressed to extremely high intensity (100's T to 1000T) in the target plasma, to slow down the heat transport to the liner and to increase the energy deposition of charged-particle fusion products. This has several compounding beneficial effects. It leads to longer energy confinement time compared with conventional ICF without magnetized target, and thus permits the use of much lower plasma density to produce reasonable burn-up fraction. The compounding effects of lower plasma density and the magneto-insulation of the target lead to greatly reduced compressional heating power on the target. The increased energy deposition rate of charged-particle fusion products also helps to lower the energy threshold required for ignition and increasing the burn-up fraction. The reduction in ignition energy and the compressional power compound to lead to reduced system size, mass and R&D cost. It is a fusion approach that has an affordable R&D pathway, and appears attractive for propulsion application in the nearer term.

  12. Evidence for the AGN nature of LINERs

    NASA Astrophysics Data System (ADS)

    González-Martín, O.; Masegosa, J.; Márquez, I.; Jiménez-Bailón, E.

    2007-04-01

    Low-luminosity AGNs (LLAGNs), which make up the vast majority of the AGN population, may yield important clues into the origin and evolution of nuclear activity, constituting a perfect laboratory to investigate the connection between galaxies in which the central black holes are active and those in which they are quiescent. The precence of a compact X-ray nucleus may provide evidences about their AGN nature. Chandra's excellent resolution allows an investigation of the X-ray nuclear properties of these galaxies. Low Ionization Nuclear-Emission Ragions (LINERs) have been selected from the catalogue by Carrillo et al. (1999). Data on 51 out of the initial 495 optical LINERs are found with the required signal-to-noise. The X-ray morphology has been classified attending to their nuclear compactness in the hard band (4.5-8 keV) into 2 categories: AGN-like nuclei (those with a clearly identified unresolved nuclear source) and Starburst-like nuclei (the ones without a clear nuclear source). 59% of the total sample are classified as AGNs with a median luminosity of 2.5x 1040 erg/s, which is an order of magnitude greather than for SB-like nuclei. The spectral fitting implies that most of the objects need a non-negligible contribution from a non-thermal component. Color-Color diagrams are defined which allow us to compute physical parameters to analyze the origin of the X-ray emission. This method is specially useful for galaxies with low S/N for which no spectral fitting can be performed. The presence of an AGN seems to be the most natural explanation for the origin of the power-law component. A comparative sample of Seyfert 2 objects has been compiled from Chandra archive, to look for common properties or eventual differences between both AGN populations.

  13. Magnetized Target Fusion Driven by Plasma Liners

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Kirkpatrick, Ronald C.; Knapp, Charles E.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Magnetized target fusion is an emerging, relatively unexplored approach to fusion for electrical power and propulsion application. The physical principles of the concept are founded upon both inertial confinement fusion (ICF) and magnetic confinement fusion (MCF). It attempts to combine the favorable attributes of both these orthogonal approaches to fusion, but at the same time, avoiding the extreme technical challenges of both by exploiting a fusion regime intermediate between them. It uses a material liner to compress, heat and contain the fusion reacting plasma (the target plasma) mentally. By doing so, the fusion burn could be made to occur at plasma densities as high as six orders of magnitude higher than conventional MCF such as tokamak, thus leading to an approximately three orders of magnitude reduction in the plasma energy required for ignition. It also uses a transient magnetic field, compressed to extremely high intensity (100's T to 1000T) in the target plasma, to slow down the heat transport to the liner and to increase the energy deposition of charged-particle fusion products. This has several compounding beneficial effects. It leads to longer energy confinement time compared with conventional ICF without magnetized target, and thus permits the use of much lower plasma density to produce reasonable burn-up fraction. The compounding effects of lower plasma density and the magneto-insulation of the target lead to greatly reduced compressional heating power on the target. The increased energy deposition rate of charged-particle fusion products also helps to lower the energy threshold required for ignition and increasing the burn-up fraction. The reduction in ignition energy and the compressional power compound to lead to reduced system size, mass and R&D cost. It is a fusion approach that has an affordable R&D pathway, and appears attractive for propulsion application in the nearer term.

  14. Striation Formation in Cylindrical Liners Made of Various Materials Driven by a 1 MA Pulsed Power Generator

    NASA Astrophysics Data System (ADS)

    Atoyan, Levon; Byvank, Tom; Engelbrecht, Joseph; Greenly, John; Pikuz, Sergei; Potter, William; Shelkovenko, Tania; Kusse, Bruce; Hammer, David

    2016-10-01

    Peterson et al. found on the 20 MA Z machine that, without any applied external axial magnetic field, horizontal striations appear in radiographic images of a metal liner [Phys. Plasmas 19, 092701, 2012], a result that has been reproduced on other pulsed power machines since. In this work we present experimental results of horizontal striations on the 1 MA, 100-200 ns COBRA pulsed power generator [T. A. Shelkovenko et al., Rev. Sci. Instrum. 77, 10F521, 2006]. The pattern is observed in our experiments using extreme ultraviolet imaging, laser imaging, and X-ray backlighting. Using this combination of diagnostics, we were able to view simultaneously the pattern near the liner surface as well as in the higher density portion of the liner, displaying features with different wavelengths. Furthermore, materials such as Al, Cu, and Ti will be used for the liner to determine if the striation formation is affected by the nature of the material. This research is supported by the NNSA Stewardship Sciences Academic Programs under Department of Energy Cooperative Agreement DE-NA0001836 and DOE account DE-NA0002952.

  15. Redox-inactive metal ions modulate the reactivity and oxygen release of mononuclear non-haem iron(III)-peroxo complexes

    NASA Astrophysics Data System (ADS)

    Bang, Suhee; Lee, Yong-Min; Hong, Seungwoo; Cho, Kyung-Bin; Nishida, Yusuke; Seo, Mi Sook; Sarangi, Ritimukta; Fukuzumi, Shunichi; Nam, Wonwoo

    2014-10-01

    Redox-inactive metal ions that function as Lewis acids play pivotal roles in modulating the reactivity of oxygen-containing metal complexes and metalloenzymes, such as the oxygen-evolving complex in photosystem II and its small-molecule mimics. Here we report the synthesis and characterization of non-haem iron(III)-peroxo complexes that bind redox-inactive metal ions, (TMC)FeIII-(μ,η2:η2-O2)-Mn+ (Mn+ = Sr2+, Ca2+, Zn2+, Lu3+, Y3+ and Sc3+; TMC, 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane). We demonstrate that the Ca2+ and Sr2+ complexes showed similar electrochemical properties and reactivities in one-electron oxidation or reduction reactions. However, the properties and reactivities of complexes formed with stronger Lewis acidities were found to be markedly different. Complexes that contain Ca2+ or Sr2+ ions were oxidized by an electron acceptor to release O2, whereas the release of O2 did not occur for complexes that bind stronger Lewis acids. We discuss these results in the light of the functional role of the Ca2+ ion in the oxidation of water to dioxygen by the oxygen-evolving complex.

  16. Interaction of Uranium Mill Tailings Leachate with Soils and Clay Liners

    SciTech Connect

    Gee, G. W.; Campbell, A. C.; Sherwood, D. R.; Strickert, R. G.; Phillips, S. J.

    1980-06-01

    This study evaluates leachate-soil interactions that will take place at the Morton Ranch for certain disposal alternatives. Laboratory tests were conducted to evaluate the following: 1) physical and chemical characteristics of geologic materials from the Morton Ranch. 2) physical and chemical characteristics of acid leach tailings and tallings solution, 3) leaching tests with selected tailings materials and leach solutions to evaluate the leachability of contaminants with time under specific disposal alternatives, 4) adsorption studies measuring the sorption characteristics of heavy metals and radionuclides on the geologic materials at Morton Ranch, 5) clay liner stability tests to evaluate effects of acid leachate on clay mineralogy and clay permeability.

  17. 2-[(8-Hydroxyquinolinyl)methylene]hydrazinecarboxamide: expanding the coordination sphere of 8-hydroxyquinoline for coordination of rare-earth metal(III) ions.

    PubMed

    Albrecht, Markus; Osetska, Olga; Fröhlich, Roland

    2005-12-07

    The semicarbazone of 8-hydroxyquinoline-2-carbaldehyde can be easily synthesized and is an effective tetradentate ligand for the coordination of rare-earth(III) ions. Investigations with yttrium(III) and lanthanum(III) in solution and in the solid state show, that the small yttrium ion can form 2 : 2 (1 : 1 stoichiometry) and 2 : 1 ligand to metal complexes (X-ray structures: [LY(NO3)(DMF)2]2Cl2 x 2DMF and [LL'Y] x 3MeOH x Et2O). With the larger lanthanum(III) ion only a well defined 1 : 1 complex (X-ray structure: [LLa(NO3)(MeOH)2]2(NO3)2) can be observed but probably 2 : 1 complexes are also formed. The X-ray structure analyses of [(L-H)MCl3] x MeOH (M = Er, Ho) and Na[(micro-NO3){LEu(NO3)2}2] x 2DMF show different coordination modes of the ligand. It can coordinate in its deprotonated but also in the protonated form.

  18. Cu(II) and Zn(II) adsorption capacity of three different clay liner materials.

    PubMed

    Musso, T B; Parolo, M E; Pettinari, G; Francisca, F M

    2014-12-15

    Sorption of Cu(II) and Zn(II) on three natural clays meeting the international requirements for use as liners was evaluated by means of batch tests. The purpose of this research was to determine the retention capacities of the clays for metal cations commonly present in urban solid waste leachates. The pH and ionic strength conditions were set at values frequently found in real leachates. The changes observed in the XRD patterns and FTIR spectra upon adsorption can be considered an evidence of clay-metal electrostatic interaction. The Langmuir model was found to best describe the sorption processes, offering maximum sorption capacities from 8.16 to 56.89 mg/g for Cu(II) and from 49.59 to 103.83 mg/g for Zn(II). All samples remove more Zn(II) than Cu(II), which may be related to the different geometry of the hydrated Cu(II) cation. The total amount of metal sorption was strongly influenced by the total specific surface area, the presence of carbonates and the smectite content of the clays. In addition to their known quality as physical barriers, the adsorbed amounts obtained indicate the suitability of the tested clays to contribute to the retardation of Cu(II) and Zn(II) transport through clay liners.

  19. Removal of divalent heavy metals (Cd, Cu, Pb, and Zn) and arsenic(III) from aqueous solutions using scoria: kinetics and equilibria of sorption.

    PubMed

    Kwon, Jang-Soon; Yun, Seong-Taek; Lee, Jong-Hwa; Kim, Soon-Oh; Jo, Ho Young

    2010-02-15

    Kinetic and equilibrium sorption experiments were conducted on removal of divalent heavy metals (Pb(II), Cu(II), Zn(II), Cd(II)) and trivalent arsenic (As(III)) from aqueous solutions by scoria (a vesicular pyroclastic rock with basaltic composition) from Jeju Island, Korea, in order to examine its potential use as an efficient sorbent. The removal efficiencies of Pb, Cu, Zn, Cd, and As by the scoria (size=0.1-0.2mm, dose=60gL(-1)) were 94, 70, 63, 59, and 14%, respectively, after a reaction time of 24h under a sorbate concentration of 1mM and the solution pH of 5.0. A careful examination on ionic concentrations in sorption batches suggested that sorption behaviors of heavy metals onto scoria are mainly controlled by cation exchange. On the other hand, arsenic appeared to be sensitive to specific sorption onto hematite (a minor constituent of scoria). Equilibrium sorption tests indicated that the removal efficiency for heavy metals increases with increasing pH of aqueous solutions, which is resulted from precipitation as hydroxides. Similarly, multi-component systems containing heavy metals and arsenic showed that the arsenic removal increases with increasing pH of aqueous solutions, which can be attributed to coprecipitation with metal hydroxides. The empirically determined sorption kinetics were well fitted to a pseudo-second order model, while equilibrium sorption data for heavy metals and arsenic onto scoria were consistent with the Langmuir and Freundlich isotherms, respectively. Natural scoria studied in this work is an efficient sorbent for concurrent removal of divalent heavy metals and arsenic.

  20. Efficient biodegradation of acephate by Pseudomonas pseudoalcaligenes PS-5 in the presence and absence of heavy metal ions [Cu(II) and Fe(III)], and humic acid.

    PubMed

    Singh, Simranjeet; Kumar, Vijay; Upadhyay, Niraj; Singh, Joginder; Singla, Sourav; Datta, Shivika

    2017-08-01

    The present study was intended to investigate the biodegradation of acephate in aqueous media in the presence and in the absence of metal ions [Fe(III) and Cu(II)], and humic acid (HA). Biodegradations were performed using Pseudomonas pseudoalcaligenes PS-5 (PS-5) isolated from the heavy metal polluted site. Biodegradations were monitored by UV-Visible, FTIR, and electron spray ionization-mass spectrometry (ESI-MS) analyses. ESI-MS analysis revealed that PS-5 degraded acephate to two metabolites showing intense ions at mass-to-charge ratios (m/z) 62 and 97. The observed kinetic was the pseudo-first order, and half-life periods (t1/2) were 2.79 d(-1) (of PS-5 + acephate), 3.45 d(-1) [of PS-5 + acephate + Fe(III)], 3.16 d(-1) [of PS-5 + acephate + Cu(II)], and 5.54 d(-1) (of PS-5 + acephate + HA). A significant decrease in degradation rate of acephate was noticed in the presence of HA, and the same was confirmed by UV-Visible and TGA analyses. Strong aggregation behavior of acephate with humic acid in aqueous media was the major cause behind the slow degradation rate of acephate . New results on acephate metabolism by strain PS-5 in the presence and in the absence of metal ions [Fe(III) and Cu(II)] and humic acid were obtained. Results confirmed that Pseudomonas pseudoalcaligenes strain PS-5 was capable of mineralization of the acephate without formation of toxic metabolite methamidophos. More significantly, the Pseudomonas pseudoalcaligenes strain PS-5 could be useful as potential biological agents in effective bioremediation campaign for multi-polluted environments.

  1. Metal migration processes in homo- and heterobimetallic bismuth(III)-lead(II) porphyrin complexes: emergence of allosteric Newton's cradle-like devices.

    PubMed

    Najjari, Btissam; Le Gac, Stéphane; Roisnel, Thierry; Dorcet, Vincent; Boitrel, Bernard

    2012-09-26

    Metal ion migration in a bis-strapped porphyrin ligand with overhanging carboxylate groups has been investigated in solution. Two types of homobimetallic complexes are generated with Pb(II) and Bi(III) cations, which stand on both sides of the macrocycle: (i) a dissymmetric complex with one cation bound to the porphyrin N core and the other cation hung over the N core through bonding with a carboxylate of a strap; (ii) a C(2)-symmetric complex with both cations coordinated to the N core and to the carboxylate groups of the straps. Variable-temperature NMR studies and 2D rotational Overhauser effect spectroscopy NMR experiments have shown that in the former dissymmetric complexes, the two cations undergo a coupled intramolecular migration resulting in exchange of their coordination modes. Such complexes constitute active states of Newton's cradle-like devices (NCDs), with the ion migration rate depending on the lability of the metal-ligand interactions [Pb(II) faster than Bi(III) NCDs]. On the other hand, the C(2)-symmetric complexes constitute either an inactive state [with Pb(II)] or a resting state [with Bi(III)] of an NCD, since they correspond respectively to a precursor or an intermediate in the motion of the cations. The NCDs are under both allosteric and acid-base control: (i) with Pb(II), the addition of an allosteric effector such as an acetate anion to the medium allows the conversion of the symmetric form to the dissymmetric one, thus triggering the Newton's cradle-like motion of the cations; (ii) with Bi(III), a lifted state was converted to a resting one by the addition of protons and then restored by the addition of a base. As an extension to nondegenerate systems, a heterobimetallic Bi(III)-Pb(II) complex was selectively obtained, and it constitutes a frozen lifted state of a dissymmetric NCD. All of these homo- and hetero-NCDs could be successively formed by selective metal ion exchange. These unique findings open the way to novel tristable devices.

  2. Tokamak with liquid metal for inducing toroidal electrical field

    DOEpatents

    Ohkawa, Tihiro

    1981-01-01

    A tokamak apparatus includes a vessel for defining a reservoir and confining liquid therein. A toroidal liner disposed within said vessel defines a toroidal space within the liner confines gas therein. Liquid metal fills the reservoir outside the liner. A magnetic field is established in the liquid metal to develop magnetic flux linking the toroidal space. The gas is ionized. The liquid metal and the toroidal space are moved relative to one another transversely of the space to generate electric current in the ionized gas in the toroidal space about its major axis and thereby heat plasma developed in the toroidal space.

  3. High-speed velocimetry inside imploding cylindrical liners

    NASA Astrophysics Data System (ADS)

    Dolan, Daniel; Lemke, Ray; Dalton, Devon; Harding, Eric; McBride, Ryan; Martin, Matthew; Blue, Brent; Walker, Scott

    2014-03-01

    Dynamic planar compression is conceptually simple but difficult to maintain at extreme pressure (>5 Mbar). Higher pressures are attainable with imploding cylindrical liners, using Photonic Doppler velocimetry (PDV) to track the liner interior. PDV measures Doppler shift directly--1 GHz of beat frequency for every 1 km/s of velocity--requiring a special ``leapfrog'' approach for liners traveling in excess of 20 km/s. Single-point and multi-point PDV measurements have been performed in aluminum, beryllium, and tantalum liners under ramp compression, and the technique can readily applied to other implosion experiments. Combined with electrical current diagnostics, these measurements test thermodynamic equations of state at pressures up to 10 MBar and beyond. Sandia National Laboratories is a multi-program laboratory 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-AC04-94AL85.

  4. Design of crusher liner based on time - varying uncertainty theory

    NASA Astrophysics Data System (ADS)

    Tang, J. C.; Shi, B. Q.; Yu, H. J.; Wang, R. J.; Zhang, W. Y.

    2017-09-01

    This article puts forward the time-dependent design method considering the load fluctuation factors for the liner based on the time-varying uncertainty theory. In this method, the time-varying uncertainty design model of liner is constructed by introducing the parameters that affect the wear rate, the volatility and the drift rate. Based on the design example, the timevarying design outline of the moving cone liner is obtained. Based on the theory of minimum wear, the gap curve of wear resistant cavity is designed, and the optimized cavity is obtained by the combination of the thickness of the cone and the cavity gap. Taking the PYGB1821 multi cylinder hydraulic cone crusher as an example, it is proved that the service life of the new liner is improved by more than 14.3%.

  5. X-ray emission from LINERs observed with ASCA

    NASA Astrophysics Data System (ADS)

    Terashima, Y.

    We searched for evidence of the presence of AGN in LINERs using X-ray images and spectra up to 10 keV obtained with ASCA. We detected hard point-like nuclear sources with X-ray luminosities of 1040 - 1041 ergs s-1 from LINER 1s. Their Hα luminosities are positively correlated with the X-ray luminosities. These facts strongly support that these LINER 1s are ionized by low luminosity AGN. LINER 2s in the present sample have systematically lower X-ray to Hα luminosity ratio (LXLHα) suggesting that there exist other ionizing source or that the AGN is heavily obscured even at energies above 2 keV. X-ray properties of low luminosity AGNs are also discussed.

  6. Method of repairing a wellbore liner for sand control

    SciTech Connect

    Dees, J.M.

    1992-10-13

    This patent describes a method of repairing a damaged wellbore liner for controlling sand and other fine materials. It comprises: positioning a quantity of fluid resin material in alignment with the portion of the wellbore liner to be repaired; positioning a gas generator in proximity with the fluid resin material; actuating the gas generator to increase wellbore pressure in a substantially instantaneous manner to a pressure substantially in excess of well pressure to force the fluid resin material from the wellbore into the damaged area of the wellbore liner; and subsequently polymerizing the resin material to form a consolidated, porous permeable matrix that allows the flow of production fluid into the well while preventing the flow of sand, or other fine materials into the well through the previously damaged area of the wellbore liner.

  7. Experimental Impedance of Single Liner Elements with Bias Flow

    NASA Technical Reports Server (NTRS)

    Follet, J. I.; Betts, J. F.; Kelly, Jeffrey J.; Thomas, Russell H.

    2000-01-01

    An experimental investigation was conducted to generate a high quality database, from which the effects of a mean bias flow on the acoustic impedance of lumped-element single-degree-of-freedom liners was determined. Acoustic impedance measurements were made using the standard two-microphone method in the NASA Langley Normal Incidence Tube. Each liner consisted of a perforated sheet with a constant-area cavity. Liner resistance was shown to increase and to become less frequency and sound pressure level dependent as the bias flow was increased. The resistance was also consistently lower for a negative bias flow (suction) than for a positive bias flow (blowing) of equal magnitude. The slope of the liner reactance decreased with increased flow.

  8. Survey of Technologies for Monitoring Containment Liners and Covers

    EPA Pesticide Factsheets

    The report provides information on innovative long-term monitoring technologies to detect contaminant releases beneath a liner containment system and identify potential problems with the integrity of final containment covers.

  9. Acoustic Liner Drag: A Parametric Study of Conventional Configurations

    NASA Technical Reports Server (NTRS)

    Howerton, Brian M.; Jones, Michael G.

    2015-01-01

    Interest in the characterization of the aerodynamic drag performance of acoustic liners has increased in the past several years. This paper details experiments in NASA Langley's Grazing Flow Impedance Tube to quantify the relative drag of several conventional perforate-over-honeycomb liner configurations. For a fixed porosity, facesheet hole diameter and cavity depth are varied to study the effect of each. These configurations are selected to span the range of conventional liner geometries used in commercial aircraft engines. Detailed static pressure and acoustic measurements are made for grazing flows up to M=0.5 at 140 dB SPL for tones between 400 and 2800 Hz. These measurements are used to calculate a resistance factor (?) for each configuration. Analysis shows a correlation between perforate hole size and the resistance factor but cavity depth seems to have little influence. Acoustic effects on liner drag are observed to be limited to the lower Mach numbers included in this investigation.

  10. Mechanistic insights on iodine(III) promoted metal-free dual C-H activation involved in the formation of a spirocyclic bis-oxindole.

    PubMed

    Sreenithya, A; Sunoj, Raghavan B

    2014-12-05

    The mechanism of a metal-free, phenyliodine(III) bis(trifluoroacetate) promoted, dual aryl C-H activation of an anilide to a spirocyclic bis-oxindole is examined using density functional theory (M06-2X). The most preferred pathway proceeds through the involvement of a novel iodonium ion intermediate and a pivotal trifluoroacetate counterion. The two sequential aryl C-H activations, assisted by trifluoroacetate as well as the superior leaving group ability of PhI, facilitate the formation of spirocyclic bis-oxindole.

  11. Configuration Effects on Acoustic Performance of a Duct Liner

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Brown, Martha C.; Jones, Michael G.; Nark, Douglas; Howerton, Brian M.

    2008-01-01

    Continued success in aircraft engine noise reduction necessitates ever more complete understanding of the effect that flow path geometry has on sound propagation in the engine. The Curved Duct Test Rig (CDTR) has been developed at NASA Langley Research Center to investigate sound propagation through a duct of comparable size (approximately the gap of GE90) and physical characteristics to the aft bypass duct of typical aircraft engines. The liner test section is designed to mimic the outer/inner walls of an engine exhaust bypass duct that has been unrolled circumferentially. Experiments to investigate the effect of curvature along the flow path on the acoustic performance of a test liner are performed in the CDTR and reported in this paper. Flow paths investigated include both straight and curved with offsets from the inlet to the discharge plane of and 1 duct width, respectively. The test liners are installed on the side walls of the liner test section. The liner samples are perforate over honeycomb core, which design is typical of liners installed in aircraft nacelles. In addition to fully treated side walls, combinations of treated and acoustically rigid walls are investigated. While curvature in the hard wall duct is found not to reduce the incident sound significantly, it does cause mode scattering. It is found that asymmetry of liner treatment causes scattering of the incident mode into less attenuated modes, which degrades the overall liner attenuation. It is also found that symmetry of liner treatment enhances liner performance by eliminating scattering into less attenuated modes. Comparisons of measured liner attenuation with numerical results predicted by an analytic model based on the parabolic approximation (CDUCT-LaRC) have also been made and are reported in this paper. The effect of curvature in the rigid wall configuration estimated by CDUCT-LaRC is similar to the observed results, and the mode scattering seen in the measurements also occurs in the

  12. Refractory Metal Liner Processing for M242 Medium Caliber Barrels

    DTIC Science & Technology

    2013-01-01

    used in these experiments was Dow Corning Silastic1 RTV (room temperature vulcanization). A 5-in steel load rod was then used to transfer the load...in) Bond Strength (psi) 1 742.7 0.199 1.095 1085 2 702 0.194 1.094 1053 3 664 0.197 1.091 983 4 790.3 0.198 1.091 1165 5 834.9 0.198 1.095 1226...internal pressure in a gun tube required to cause plastic deformation RTV room temperature vulcanization σy yield strength 26 NO. OF

  13. Modeling Explosive Cladding of Metallic Liners to Gun Tubes

    DTIC Science & Technology

    2010-01-01

    velocity of the explosive. Using the experimental Dfor the Chapman - Jouguet state and assuming the empirical v2£ is valid at seven volume expansions...process. EQUATION OF STATE The explosives used in this cladding effort have very low energy levels compared to traditional military explosives. A...impact for all the steps modeled. This indicates that a traditional Gurney assumption for final tube velocity is not accurate, as a final asymptotic

  14. Synthesis, characterization and investigation of the photophysical and photochemical properties of highly soluble novel metal-free, zinc(II), and indium(III) phthalocyanines substituted with 2,3,6-trimethylphenoxy moieties.

    PubMed

    Gürel, Ekrem; Pişkin, Mehmet; Altun, Selçuk; Odabaş, Zafer; Durmuş, Mahmut

    2015-04-07

    This work presents the synthesis and characterization of metal-free, zinc(II), and indium(III)acetate phthalocyanines substituted with 2,3,6-trimethylphenoxy groups at the peripheral and non-peripheral positions. The photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen generation and photodegradation under light irradiation) properties of these novel phthalocyanines and unsubstituted zinc(II) and indium(III)acetate phthalocyanines were investigated in dimethylformamide solution. The effects of the types of substituents and their positions and the variety of central metal ions on the phthalocyanine core on their spectroscopic, photophysical and photochemical properties were also determined. The studied 2,3,6-trimethylphenoxy substituted metal-free, zinc(II) and indium(III)acetate phthalocyanines especially indium(III)acetate derivatives exhibited appropriate photophysical and photochemical properties such as high singlet oxygen generation and these phthalocyanines can be potential Type II photosensitizers for photodynamic therapy in cancer applications.

  15. Small gas turbine combustor study - Combustor liner evaluation

    NASA Technical Reports Server (NTRS)

    Norgren, C. T.; Riddlebaugh, S. M.

    1983-01-01

    A reverse flow combustor liner constructed of Lamilloy (a multilaminate transpiration type material) is compared both analytically and experimentally with a conventional splash film-cooled design with the same combustor configuration. Comparison of selected critical combustor panels indicated that it was possible to maintain the liner temperature similar between the two configurations using 50 percent less coolant for the Lamilloy as compared with the reference film-cooled combustor. Additional benefits indicated improvement in outlet temperature distribution and NOx emission level.

  16. Landing Gear Door Liners for Airframe Noise Reduction

    NASA Technical Reports Server (NTRS)

    Jones, Michael G. (Inventor); Howerton, Brian M. (Inventor); Van De Ven, Thomas (Inventor)

    2014-01-01

    A landing gear door for retractable landing gear of aircraft includes an acoustic liner. The acoustic liner includes one or more internal cavities or chambers having one or more openings that inhibit the generation of sound at the surface and/or absorb sound generated during operation of the aircraft. The landing gear door may include a plurality of internal chambers having different geometries to thereby absorb broadband noise.

  17. Flap Side Edge Liners for Airframe Noise Reduction

    NASA Technical Reports Server (NTRS)

    Jones, Michael G. (Inventor); Khorrami, Mehdi R. (Inventor); Choudhari, Meelan M. (Inventor); Howerton, Brian M. (Inventor)

    2014-01-01

    One or more acoustic liners comprising internal chambers or passageways that absorb energy from a noise source on the aircraft are disclosed. The acoustic liners may be positioned at the ends of flaps of an aircraft wing to provide broadband noise absorption and/or dampen the noise producing unsteady flow features, and to reduce the amount of noise generated due to unsteady flow at the inboard and/or outboard end edges of a flap.

  18. The Internalization of Iron and Manganese as Discrete Particles During the Bioreduction of Fe(III) and Mn(IV) by a Dissimilatory Metal-Reducing Bacterium

    NASA Astrophysics Data System (ADS)

    Glasauer, S. M.; Langley, S.; Beveridge, T. J.; Fakra, S.; Tyliszczak, T.; Shuh, D.; Boyanov, M.; Kemner, K.

    2006-12-01

    Shewanella putrefaciens CN32 is a dissimilatory iron-reducing, facultative anaerobe that substitutes Fe3+ as well as other metal and organic substrates for O2 as the terminal electron acceptor of the electron transport chain to gain energy for growth and metabolism (1). During the dissimilatory reduction (DR) of hydrous ferric oxide (HFO), the bacteria produce Fe2+ at the cell surface which results in the precipitation of FeII mineral phases external to the cell. We have shown previously that, at the same time the extracellular minerals are produced, intracellular granules of mineral Fe precipitate as well. These granules form clusters that are located at the poles of the cells (2). We have recently characterized the intracellular particles using X-ray microspectroscopy, which reveals that the particles contain FeII and FeIII in a 1:1 ratio (3). In order to determine if the internal Fe particles represent a general phenomenon of dissimilatory metal reduction, we have extended our investigations on the formation of internal mineral phases to Mn(IV) as well as V(V) (4, 5). Both metals are relatively non-toxic to bacteria, exist in several oxidation states in earth surface environments, and are respired by CN32. Culture experiments were combined with electron microscopy (EM) and scanning transmission X-ray microspectroscopy (STXM) studies of CN32 during respiration of Mn(IV) and V(V). The use of EM and STXM techniques in concert allowed us to detail cell wall ultrastructure and resolve metal chemical states at the nanometer scale. The final extracellular products of Mn(IV) and V(V) respiration were Mn(II) and V(III)/V(IV). Intracellular particles were only observed during the dissimilatory reduction of Mn(IV); however, the particles were not as abundant as those appearing during the bioreduction of HFO. This indicates that the uptake mechanism has specificity for divalent cations, although it is likely that differences in the rate of reduced metal accumulation at the

  19. Electric Plasma Arc-Lamp Combustor Liner Durability Test System Developed

    NASA Technical Reports Server (NTRS)

    Goldsby, Jon C.; Halbig, Michael C.

    2000-01-01

    current. One of the special features of this configuration is the creation of hoop stress states within the cylinder, which up this point have not been obtainable in planar coupon tests. This facility will allow various operational modes, including accelerated tests of thermal transients simulating the effects of repeated engine ignition as well as prescribed thermal and mechanical histories to simulate various duty cycle profiles. Tests can now be performed on thermal-barrier-coated metallic liners and ceramic composite liners that require a combination of high heat flux and controlled mechanical stresses.

  20. Theoretical study of one-electron-oxidized salen complexes of group 7 (Mn(iii), Tc(iii), and Re(iii)) and group 10 metals (Ni(ii), Pd(ii), and Pt(ii)) with the 3D-RISM-GMC-QDPT method: localized vs. delocalized ground and excited states in solution.

    PubMed

    Aono, Shinji; Nakagaki, Masayuki; Sakaki, Shigeyoshi

    2017-06-28

    One-electron oxidized salen complexes of Mn(iii) and Ni(ii) were recently reported to be unique mixed-valence compounds. Their electronic structures are sensitive to the salen ligand and solvation. We systematically investigated a series of one-electron oxidized salen complexes of group 7 metals (Mn(iii), Tc(iii), and Re(iii)) and their group 10 analogues (Ni(ii), Pd(ii), and Pt(ii)) using the general multi-configuration reference quasi-degenerate perturbation theory (GMC-QDPT) which was combined with the three-dimensional reference interaction site model self-consistent field theory (3D-RISM-SCF) to incorporate the solvation effect. The calculated absorption spectra and electronic structures agree with the experimental observation. The one-electron oxidized salen complexes of group 10 metals with a symmetrical salen ligand have a delocalized electronic structure belonging to class III (Robin-Day classification) in weakly polar solvents. The tendency for taking a delocalized electronic structure increases in the order Pd(ii) < Ni(ii) < Pt(ii). When the salen ligand is asymmetrical, the one-electron oxidized complexes have a localized electronic structure belonging to class II. The group 7 analogues of Mn(iii) and Tc(iii) have a localized electronic structure belonging to class II even in weakly polar solvents and even with a symmetrical salen ligand. However, the one-electron oxidized Re(iii) complex has no mixed-valence nature because one-electron oxidation occurs on the Re center. Theoretical study shows that the solvation effect plays a crucial role in determining the mixed-valence character, class II or III, and thereby its incorporation in the calculation is indispensable for correctly describing geometries, electronic structures, and the inter-valence absorption spectra of these complexes. The d orbital energy is one of the most important factors for determining the localization/delocalization electronic structures in these complexes. Detailed discussion of

  1. Synthesis of, characterization of, and photoinduced processes in polymetallic triad complexes containing Fe(II), Ru(II), and Rh(III) metal centers

    SciTech Connect

    Ronco, S.E. |; Thompson, D.W.; Gahan, S.L.; Petersen, J.D. |

    1998-04-20

    A series of new trimetallic mixed complexes containing Fe(II), Ru(II), and Rh(III) metal centers have been prepared and characterized, and their excited-state properties in a nanosecond time domain have been investigated. These new compounds were synthesized by following a building block strategy from monomeric Rh(III) and Ru(II) polyazines and tetracyanoferrate(II) ions. The products generated in each synthetic step were fully characterized and their excited-state properties investigated. These new trimetallic complexes, [(CN){sub 4}Fe{sup II}(BL(1))Ru{sup II}(bpy)-(BL(2))Rh{sup III}(tpy)(MQ{sup +})](PF{sub 6}){sub 4} (tpy = 2,2{prime}:6{prime}:2{double_prime}-terpyridine; BL(1) = 2,3-bis(2-pyridyl)pyrazine (dpp) or 2,2{prime}-bipyrimidine (bpm); BL(2) = dpp or bpm; MQ{sup +} = N-methyl-4,4{prime}-bipyridinium (monoquat)), consist of three fundamental parts linked by bridging ligands (1) an electron donor group, the tetracyanoferrate(II) unit; (2) an antenna fragment, the Ru(II) polypyridyl moiety; and (3) an electron acceptor group. The electron acceptor group is a Rh(III) polypyridyl that contains the ligands tpy and MQ{sup +}. No emission was observed in any of the reported complexes either in fluid solutions at room temperature or in glassy solutions at 77 K. Time-resolved experiments conducted on these triads showed formation of a transient intermediate within the laser pulse. Redox properties and transient absorption observations helped the authors to identify the nature of this intermediate as an Fe(III)/Ru(II) mixed-valence species that decays exponentially by following a first-order law with a lifetime of {tau} {le} 70 ns in fluid solution at room temperature.

  2. Composite Liner, Multi-Megabar Shock Driver Development

    SciTech Connect

    Cochrane, J.C. Jr.; Bartsch, R.R.; Clark, D.A.; Morgan, D.V.; Anderson, W.E.; Lee, H.; Bowers, R.L.; Atchison, W.L.; Oona, H.; Stokes, J.L.; Veeser, L.R.; Broste, W.B.

    1998-10-18

    The multi-megabar shock driver development is a series of experiments in support of the Los Alamos High Energy Density Physics Experimental Program. Its purpose is to develop techniques to impact a uniform, stable, composite liner upon a high Z target to produce a multi-megabar shock for EOS studies. To date, experiments have been done on the Pegasus II capacitor bank with a current of {approximately}12MA driving the impactor liner. The driving field is {approximately}200 T at the target radius of 1cm. Data will be presented on the impactor liner. The driving field is {approximately}200 T at the target radius of 1 cm. Data will be presented on the stability and uniformity of the impactor liner when it impacts the target cylinder. Three experiments have been done with emphasis on liner development. Shock pressures greater than a megabar have been done with emphasis on liner development. Shock pressures greater than a megabar have been produced with an Al target cylinder. A Pt target cylinder should produce shock pressures in th e 5-megabar range.

  3. A Conventional Liner Acoustic/Drag Interaction Benchmark Database

    NASA Technical Reports Server (NTRS)

    Howerton, Brian M.; Jones, Michael G.

    2017-01-01

    The aerodynamic drag of acoustic liners has become a significant topic in the design of such for aircraft noise applications. In order to evaluate the benefits of concepts designed to reduce liner drag, it is necessary to establish the baseline performance of liners employing the typical design features of conventional configurations. This paper details a set of experiments in the NASA Langley Grazing Flow Impedance Tube to quantify the relative drag of a number of perforate-over-honeycomb liner configurations at flow speeds of M=0.3 and 0.5. These conventional liners are investigated to determine their resistance factors using a static pressure drop approach. Comparison of the resistance factors gives a relative measurement of liner drag. For these same flow conditions, acoustic measurements are performed with tonal excitation from 400 to 3000 Hz at source sound pressure levels of 140 and 150 dB. Educed impedance and attenuation spectra are used to determine the interaction between acoustic performance and drag.

  4. Effects of Flow Profile on Educed Acoustic Liner Impedance

    NASA Technical Reports Server (NTRS)

    Jones, Michael G.; Watson, Willie r.; Nark, Douglas M.

    2010-01-01

    This paper presents results of an investigation of the effects of shear flow profile on impedance eduction processes employed at NASA Langley. Uniform and 1-D shear-flow propagation models are used to educe the acoustic impedance of three test liners based on aeroacoustic data acquired in the Langley Grazing Flow Impedance Tube, at source levels of 130, 140 and 150 dB, and at centerline Mach numbers of 0.0, 0.3 and 0.5. A ceramic tubular, calibration liner is used to evaluate the propagation models, as this liner is expected to be insensitive to SPL, grazing flow Mach number, and flow profile effects. The propagation models are then used to investigate the effects of shear flow profile on acoustic impedances educed for two conventional perforate-over-honeycomb liners. Results achieved with the uniform-flow models follow expected trends, but those educed with the 1-D shear-flow model do not, even for the calibration liner. However, when the flow profile used with the shear-flow model is varied to increase the Mach number gradient near the wall, results computed with the shear-flow model are well matched to those achieved with the uniform-flow model. This indicates the effects of flow profile on educed acoustic liner impedance are small, but more detailed investigations of the flow field throughout the duct are needed to better understand these effects.

  5. Spherically symmetric simulation of plasma liner driven magnetoinertial fusion

    SciTech Connect

    Samulyak, Roman; Parks, Paul; Wu Lingling

    2010-09-15

    Spherically symmetric simulations of the implosion of plasma liners and compression of plasma targets in the concept of the plasma jet driven magnetoinertial fusion have been performed using the method of front tracking. The cases of single deuterium and xenon liners and double layer deuterium-xenon liners compressing various deuterium-tritium targets have been investigated, optimized for maximum fusion energy gains, and compared with theoretical predictions and scaling laws of [P. Parks, Phys. Plasmas 15, 062506 (2008)]. In agreement with the theory, the fusion gain was significantly below unity for deuterium-tritium targets compressed by Mach 60 deuterium liners. The most optimal setup for a given chamber size contained a target with the initial radius of 20 cm compressed by a 10 cm thick, Mach 60 xenon liner, achieving a fusion energy gain of 10 with 10 GJ fusion yield. Simulations also showed that composite deuterium-xenon liners reduce the energy gain due to lower target compression rates. The effect of heating of targets by alpha particles on the fusion energy gain has also been investigated.

  6. Floating junk bonnet protects liner top from debris

    SciTech Connect

    Telfer, G. ); Sweeney, D. )

    1994-09-12

    A new design of debris protection system, the floating junk bonnet, for liner tops prevents well debris from entering the liner top polished bore receptacle (PBR) and sticking the setting tools. The floating junk bonnet improves the recovery of liner setting tools from the well no matter how severe the debris problem is. Well debris (formation cuttings, fines, mud solids, cement solids, foreign bodies, etc) entering the linear top PBR during cementing operations has been a serious problem for many operators. In some cases, this problem has led to liner hanger setting tools sticking in the liner top PBR. The setting tool could then become cemented in place, resulting in an expensive fishing job or sidetrack. A prototype debris protection system was developed and tested prior to offshore application. The liner protection tool was subsequently successfully used on Nelson project development wells in the U.K. North Sea. The paper discusses debris accumulation, the junket basket, the floating junk bonnet design, test procedures, and field test results.

  7. Suppression of Helmholtz resonance using inside acoustic liner

    NASA Astrophysics Data System (ADS)

    Hong, Zhiliang; Dai, Xiwen; Zhou, Nianfa; Sun, Xiaofeng; Jing, Xiaodong

    2014-08-01

    When a Helmholtz resonator is exposed to grazing flow, an unstable shear layer at the opening can cause the occurrence of acoustic resonance under appropriate conditions. In this paper, in order to suppress the flow-induced resonance, the effects of inside acoustic liners placed on the side wall or the bottom of a Helmholtz resonator are investigated. Based on the one-dimensional sound propagation theory, the time domain impedance model of a Helmholtz resonator with inside acoustic liner is derived, and then combined with a discrete vortex model the resonant behavior of the resonator under grazing flow is simulated. Besides, an experiment is conducted to validate the present model, showing significant reduction of the peak sound pressure level achieved by the use of the side-wall liners. And the simulation results match reasonably well with the experimental data. The present results reveal that the inside acoustic liner can not only absorb the resonant sound pressure, but also suppress the fluctuation motion of the shear layer over the opening of the resonator. In all, the impact of the acoustic liners is to dampen the instability of the flow-acoustic coupled system. This demonstrates that it is a convenient and effective method for suppressing Helmholtz resonance by using inside acoustic liner.

  8. Computer method for design of acoustic liners for turbofan engines

    NASA Technical Reports Server (NTRS)

    Minner, G. L.; Rice, E. J.

    1976-01-01

    A design package is presented for the specification of acoustic liners for turbofans. An estimate of the noise generation was made based on modifications of existing noise correlations, for which the inputs are basic fan aerodynamic design variables. The method does not predict multiple pure tones. A target attenuation spectrum was calculated which was the difference between the estimated generation spectrum and a flat annoyance-weighted goal attenuated spectrum. The target spectrum was combined with a knowledge of acoustic liner performance as a function of the liner design variables to specify the acoustic design. The liner design method at present is limited to annular duct configurations. The detailed structure of the liner was specified by combining the required impedance (which is a result of the previous step) with a mathematical model relating impedance to the detailed structure. The design procedure was developed for a liner constructed of perforated sheet placed over honeycomb backing cavities. A sample calculation was carried through in order to demonstrate the design procedure, and experimental results presented show good agreement with the calculated results of the method.

  9. Microstructural examination of service exposed coal mill liner material

    SciTech Connect

    Venkateswarlu, K.; Chowdhury, S.G.; Pathak, L.C.; Ray, A.K.

    2007-10-15

    This study mainly focuses the microstructural characterisation of the service exposed coal liner. These liners are generally referred to as bull ring segments in the bowl mill of coal pulveriser systems. The failed bull ring segment was collected from a coal-fired power plant of Kolaghat thermal plant, West Bengal, India. The crack that has been observed in the middle of the liner was observed under SEM and detailed microstructural studies are made for the liner material. The hardness measurements are made and XRD is carried out to identify the phases present in the sample. The results suggest that the material confirms to high chromium cast iron and microstructural studies reveal that the cracks are mainly due to the heavy service exposed conditions where lumps of coal and silica sand falling on these liners causing severe impact and abrasion conditions. High abrasive studies on the liner material are carried out and it showed that increasing the abrasive size as well as load is responsible for higher wear loss. The results suggest that prolonged exposure to abrasion conditions results in the progressive removal of the matrix material and due to various phase transformations from austenite to martensite introduces surface volume changes and causes the generation of cracks and further lead to failure of the component.

  10. The Nature of the Energy Source in LINER's

    NASA Technical Reports Server (NTRS)

    Colina, L.; Koratkar, Anuradha

    1996-01-01

    LINER's (low-ionization nuclear emission-line regions) are found in about 30% of all bright galaxies, including luminous infrared galaxies. They form a heterogeneous class powered by a variety of ionizing mechanisms such as low-luminosity AGNs (active galactic nuclei), starbursts, shocks, or any combination of these. In early-type spirals, LINER's are powered by a low-luminosity AGN, or by an AGN surrounded by circumnuclear star-forming regions. In luminous infrared galaxies, LINER's are powered by starbursts with associated wind-related extended shocks, and an AGN may play a minor role, if any. LINER's in some FR I radio galaxies show strong evidence for the presence of a massive central black hole, and there are indications for the existence of shocks in the nuclear disks of these galaxies. Yet, the dominant ionizing mechanism for LINER's in radio-quiet ellipticals and FR I host galaxies is still unclear. Multifrequency high spatial resolution imaging and spectroscopy are essential to discriminate among the different ionizing mechanisms present in LINER's.

  11. A New Use for a Familiar Fold: the X-Ray Crystal Structure of GTP-Bound GTP Cyclohydrolase III From Methanocaldococcus Jannaschii Reveals a Two Metal Ion Catalytic Mechanism

    SciTech Connect

    Morrison, S.D.; Roberts, S.A.; Zegeer, A.M.; Montfort, W.R.; Bandarian, V.

    2009-05-26

    GTP cyclohydrolase (GCH) III from Methanocaldococcus jannaschii, which catalyzes the conversion of GTP to 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate (FAPy), has been shown to require Mg{sup 2+} for catalytic activity and is activated by monovalent cations such as K{sup +} and ammonium [Graham, D. E., Xu, H., and White, R. H. (2002) Biochemistry 41, 15074-15084]. The reaction is formally identical to that catalyzed by a GCH II ortholog (SCO 6655) from Streptomyces coelicolor; however, SCO 6655, like other GCH II proteins, is a zinc-containing protein. The structure of GCH III complexed with GTP solved at 2 {angstrom} resolution clearly shows that GCH III adopts a distinct fold that is closely related to the palm domains of phosphodiesterases, such as DNA polymerase I. GCH III is a tetramer of identical subunits; each monomer is composed of an N- and a C-terminal domain that adopt nearly superimposible structures, suggesting that the protein has arisen by gene duplication. Three metal ions were located in the active site, two of which occupy positions that are analogous to those occupied by divalent metal ions in the structures of a number of palm domain containing proteins, such as DNA polymerase I. Two conserved Asp residues that coordinate the metal ions, which are also found in palm domain containing proteins, are observed in GCH III. Site-directed variants (Asp{yields}Asn) of these residues in GCH III are less active than wild-type. The third metal ion, most likely a potassium ion, is involved in substrate recognition through coordination of O6 of GTP. The arrangement of the metal ions in the active site suggests that GCH III utilizes two metal ion catalysis. The structure of GCH III extends the repertoire of possible reactions with a palm fold to include cyclohydrolase chemistry.

  12. Interactions of tailings leachate with local liner materials found at Canonsburg, Pennsylvania.

    SciTech Connect

    Dodson, M.E.; Gee, G.W.; Serne, R.J.

    1984-04-01

    The mill tailings site at Canonsburg, Pennsylvania is the first mill site to receive remedial action under the Department of Energy's Uranium Mill Tailings Remedial Action Program. Part of this remedial action will require excavating the 53,500 m/sup 3/ (70,000 yd/sup 3/) of tailings on the site having a specific activity exceeding 100 pCi/g, and encapsulating these contaminated tailings in a clay-lined cell. As part of the remedial action effort, Pacific Northwest Laboratory has been studying the interactions of tailings and tailings leachate with locally occurring clays proposed for liner materials. These studies include physical and chemical characterization of amended and unamended local clays, chemical characterization of the tailings, column studies of tailings leached with deionized water, and column studies of clays contacted with tailings solutions to determine the attenuation properties of the proposed liner materials. Column studies of tailings leached with deionized water indicated that the Canonsburg tailings could represent a source of soluble radium-226 and uranium-238, several trace metals, cations, and the anions SO/sub 4/, NO/sub 3/, and Cl. Of these soluble contaminants, uranium-238, radium-226, the trace metals As and Mo, and the anions F and SO/sub 4/ were present at levels exceeding maximum concentration levels in the tailings leaching column effluents. However, local clays, both in amended and unamended form were effective in attenuating contaminant migration. The soil amendments tested failed to increase radium attenuation. The tailings leaching studies indicated that the tailings will produce leachates of neutral pH and relatively low contaminant levels for at least 200 years. We believe that compacting the tailings within the encapsulation cell will help to reduce leaching of contaminants from the liner system, since very low permeabilities (<10/sup -8/ cm/s) were observed for even slightly compacted tailings materials.

  13. Lanthanide Metal-Organic Frameworks with Six-Coordinated Ln(III) Ions and Free Functional Organic Sites for Adsorptions and Extensive Catalytic Activities

    NASA Astrophysics Data System (ADS)

    Zhu, Yu; Zhu, Min; Xia, Li; Wu, Yunlong; Hua, Hui; Xie, Jimin

    2016-07-01

    Three chelating-amino-functionalized lanthanide metal-organic frameworks, Y-DDQ, Dy-DDQ and Eu-DDQ, were synthesized with a flexible dicarboxylate ligand based on quinoxaline (H2DDQ = N, N‧-dibenzoic acid-2,3-diaminoquinoxaline). The three-dimensional framework is constructed by the H2DDQ linkers connecting the zigzag ladders, showing a net of sra topology. In the structures, one kind of Ln(III) ions metal centers are six-coordinated and thus can potentially behave as open metal sites (OMSs), while the free chelating amino groups can act as free functional organic sites (FOSs). The N2 and Ar adsorption behaviors indicate that these Ln-DDQ exhibits stable microporous frameworks with high surface area after remove of the solvents. Owing to presence of OMSs and FOSs, these MOFs show good ability of CO2, dyes captures and Lewis acid catalyst for cyanosilylation reaction. In view of the existing FOSs in the framework, Pd NPs were immobilized onto the MOFs through graft interactions between free chelating amino groups and metal ions precursor using postsynthetic modification. The well dispersed Pd@Ln-DDQs exhibit efficient and recyclable catalytic reduction of 4-nitrophenol to 4-aminophenol, and they can also act as an excellent catalyst for Suzuki-Miyaura cross-coupling reactions with the exposed Pd NPs.

  14. Lanthanide Metal-Organic Frameworks with Six-Coordinated Ln(III) Ions and Free Functional Organic Sites for Adsorptions and Extensive Catalytic Activities

    PubMed Central

    Zhu, Yu; Zhu, Min; Xia, Li; Wu, Yunlong; Hua, Hui; Xie, Jimin

    2016-01-01

    Three chelating-amino-functionalized lanthanide metal-organic frameworks, Y-DDQ, Dy-DDQ and Eu-DDQ, were synthesized with a flexible dicarboxylate ligand based on quinoxaline (H2DDQ = N, N′-dibenzoic acid-2,3-diaminoquinoxaline). The three-dimensional framework is constructed by the H2DDQ linkers connecting the zigzag ladders, showing a net of sra topology. In the structures, one kind of Ln(III) ions metal centers are six-coordinated and thus can potentially behave as open metal sites (OMSs), while the free chelating amino groups can act as free functional organic sites (FOSs). The N2 and Ar adsorption behaviors indicate that these Ln-DDQ exhibits stable microporous frameworks with high surface area after remove of the solvents. Owing to presence of OMSs and FOSs, these MOFs show good ability of CO2, dyes captures and Lewis acid catalyst for cyanosilylation reaction. In view of the existing FOSs in the framework, Pd NPs were immobilized onto the MOFs through graft interactions between free chelating amino groups and metal ions precursor using postsynthetic modification. The well dispersed Pd@Ln-DDQs exhibit efficient and recyclable catalytic reduction of 4-nitrophenol to 4-aminophenol, and they can also act as an excellent catalyst for Suzuki-Miyaura cross-coupling reactions with the exposed Pd NPs. PMID:27431731

  15. Forward and reverse (retro) iron(III) or gallium(III) desferrioxamine E and ring-expanded analogues prepared using metal-templated synthesis from endo-hydroxamic acid monomers.

    PubMed

    Lifa, Tulip; Tieu, William; Hocking, Rosalie K; Codd, Rachel

    2015-04-06

    A metal-templated synthesis (MTS) approach was used to preorganize the forward endo-hydroxamic acid monomer 4-[(5-aminopentyl)(hydroxy)amino]-4-oxobutanoic acid (for-PBH) about iron(III) in a 1:3 metal/ligand ratio to furnish the iron(III) siderophore for-[Fe(DFOE)] (ferrioxamine E) following peptide coupling. Substitution of for-PBH with the reverse (retro) hydroxamic acid analogue 3-(6-amino-N-hydroxyhexanamido)propanoic acid (ret-PBH) furnished ret-[Fe(DFOE)] (ret-ferrioxamine E). As isomers, for-[Fe(DFOE)] and ret-[Fe(DFOE)] gave identical mass spectrometry signals ([M + H(+)](+), m/zcalc 654.3, m/zobs 654.3), yet for-[Fe(DFOE)] eluted in a more polar window (tR = 23.44 min) than ret-[Fe(DFOE)] (tR = 28.13 min) on a C18 reverse-phase high-performance liquid chromatography (RP-HPLC) column. for-[Ga(DFOE)] (tR = 22.99 min) and ret-[Ga(DFOE)] (tR = 28.11 min) were prepared using gallium(III) as the metal-ion template and showed the same trend for the retention time. Ring-expanded analogues of for-[Fe(DFOE)] and ret-[Fe(DFOE)] were prepared from endo-hydroxamic acid monomers with one additional methylene unit in the amine-containing region, 4-[(6-aminohexyl)(hydroxy)amino]-4-oxobutanoic acid (for-HBH) or 3-(7-amino-N-hydroxyheptanamido)propanoic acid (ret-HBH), to give the corresponding tris(homoferrioxamine E) macrocycles, for-[Fe(HHDFOE)] or ret-[Fe(HHDFOE)] ([M + H(+)](+), m/zcalc 696.3, m/zobs 696.4). The MTS reaction using a constitutional isomer of for-HBH that transposed the methylene unit to the carboxylic acid containing region, 5-[(5-aminopentyl)(hydroxy)amino]-5-oxopentanoic acid (for-PPH), gave the macrocycle for-[Fe(HPDFOE)] in a yield significantly less than that for for-[Fe(HHDFOE)], with the gallium(III) analogue for-[Ga(HPDFOE)] unable to be detected. The work demonstrates the utility and limits of MTS for the assembly of macrocyclic siderophores from endo-hydroxamic acid monomers. Indirect measures (RP-HPLC order of elution, c log P values

  16. The Subaru FMOS Galaxy Redshift Survey (FastSound). III. The mass-metallicity relation and the fundamental metallicity relation at z ˜ 1.4*

    NASA Astrophysics Data System (ADS)

    Yabe, Kiyoto; Ohta, Kouji; Akiyama, Masayuki; Bunker, Andrew; Dalton, Gavin; Ellis, Richard; Glazebrook, Karl; Goto, Tomotsugu; Imanishi, Masatoshi; Iwamuro, Fumihide; Okada, Hiroyuki; Shimizu, Ikkoh; Takato, Naruhisa; Tamura, Naoyuki; Tonegawa, Motonari; Totani, Tomonori

    2015-12-01

    We present the results from a large near-infrared spectroscopic survey made with Subaru/FMOS (FastSound) consisting of ˜ 4000 galaxies at z ˜ 1.4 with significant Hα detection. We measure the gas-phase metallicity from the [N II]λ6583/Hα emission line ratio of the composite spectra in various stellar mass and star-formation rate bins. The resulting mass-metallicity relation generally agrees with previous studies obtained in a similar redshift range to that of our sample. No clear dependence of the mass-metallicity relation on star-formation rate is found. Our result at z ˜ 1.4 is roughly in agreement with the fundamental metallicity relation at z ˜ 0.1 with a fiber aperture corrected star-formation rate. We detect significant [S II]λλ6716,6731 emission lines from the composite spectra. The electron density estimated from the [S II]λλ6716,6731 line ratio ranges from 10-500 cm-3, which generally agrees with that of local galaxies. On the other hand, the distribution of our sample on [N II]λ6583/Hα vs. [S II]λλ6716,6731/Hα is different to that found locally. We estimate the nitrogen-to-oxygen abundance ratio (N/O) from the N2S2 index, and find that the N/O in galaxies at z ˜ 1.4 is significantly higher than the local values at a fixed metallicity and stellar mass. The metallicity at z ˜ 1.4 recalculated with this N/O enhancement taken into account decreases by 0.1-0.2 dex. The resulting metallicity is lower than the local fundamental metallicity relation.

  17. Super and massive AGB stars - III. Nucleosynthesis in metal-poor and very metal-poor stars - Z = 0.001 and 0.0001

    NASA Astrophysics Data System (ADS)

    Doherty, Carolyn L.; Gil-Pons, Pilar; Lau, Herbert H. B.; Lattanzio, John C.; Siess, Lionel; Campbell, Simon W.

    2014-06-01

    We present a new grid of stellar models and nucleosynthetic yields for super-AGB stars with metallicities Z = 0.001 and 0.0001, applicable for use within galactic chemical evolution models. Contrary to more metal-rich stars where hot bottom burning is the main driver of the surface composition, in these lower metallicity models the effect of third dredge-up and corrosive second dredge-up also have a strong impact on the yields. These metal-poor and very metal-poor super-AGB stars create large amounts of 4He, 13C, 14N and 27Al as well as the heavy magnesium isotopes 25Mg and 26Mg. There is a transition in yield trends at metallicity Z ≈ 0.001, below which we find positive yields of 12C, 16O, 15N and 28Si, which is not the case for higher metallicities. We explore the large uncertainties derived from wind prescriptions in super-AGB stars, finding ≈2 orders of magnitude difference in yields of 22Ne, 23Na, 24, 25, 26Mg, 27Al and our s-process proxy isotope g. We find inclusion of variable composition low-temperature molecular opacities is only critical for super-AGB stars of metallicities below Z ≈ 0.001. We analyse our results, and those in the literature, to address the question: Are super-AGB stars the polluters responsible for extreme population in the globular cluster NGC 2808? Our results, as well as those from previous studies, seem unable to satisfactorily match the extreme population in this globular cluster.

  18. A novel near monochromatic red emissive europium(III) metal-organic framework based on 1,2,4,5-benzenetetracarboxylate: From synthesis to photoluminescence studies

    NASA Astrophysics Data System (ADS)

    Lahoud, Marcelo G.; Frem, Regina C. G.; Marques, Lippy F.; Arroyos, Guilherme; Brandão, Paula; Ferreira, Rute A. S.; Carlos, Luís D.

    2017-09-01

    This work presents the synthesis, solid state characterization (infrared spectroscopy, thermal analysis (TGA/DTA), powder and single crystal X-ray diffraction) and photoluminescence studies of a new europium metal-organic framework (MOF), [Eu2(Btec)1,5(H2O)]n (Btec4-=1,2,4,5-benzenetetracarboxylate anion). Single crystal X-ray diffraction analysis reveals that the material has a three-dimensional network, with two crystallographically independent Eu(III) ions adopting different coordination geometries. This structure presents one of the Btec4- anions acting as a μ8-bridging linker, with the carboxylate groups in distinct connection to Eu(III) ions, culminating into an unknown coordination mode for the linker. The results of thermogravimetric analyses indicate that the MOF has high thermal stability, with this characteristic being of great interest for the application of these compounds in several fields such as catalysis and photonics. The luminescent properties showed that the Eu(III) ions are a local-spectroscopic probe, with the compound presenting a red emission when excited in the UV spectral region with absolute emission quantum yield values of 0.48 ± 0.05. The thermal dependence on the intensity of the transitions originating from the 7F1 level, especially the 7F1 → 5D1 transition, was studied. These results opens the possibility to test this MOF [Eu2(Btec)1.5(H2O)]n in the field of molecular thermometry.

  19. Geosynthetic clay liners - slope stability field study

    SciTech Connect

    Carson, D.A.; Daniel, D.E.; Koerner, R.M.; Bonaparte, R.

    1997-12-31

    A field research project was developed to examine the internal shear performance of geosynthetic clay liners (GCLs). Several combinations of cross sections were assembled using GCL materials that were available at the time of project initiation. The cross sections utilized were intended to simulate landfill cover applications. Thirteen (13) resulting test plots were constructed on two different slope angles, and each plot is instrumented for physical displacement and soil moisture characteristics. Test plots were constructed in a manner that dictated the shear plane in the clay portion of the GCL product. The project purpose is to assess field performance and to verify design parameters associated with the application of GCLs in waste containment applications. Interim research data shows that test slopes on 2H:1V show global deformation, but little internal shear evidence, and the 3H:1V slopes show little deformation at approximately 650 days. The research is ongoing, and this paper presents the most recent information available from the project.

  20. Laser-driven magnetized liner inertial fusion

    DOE PAGES

    Davies, J. R.; Barnak, D. H.; Betti, R.; ...

    2017-06-05

    A laser-driven, magnetized liner inertial fusion (MagLIF) experiment is designed in this paper for the OMEGA Laser System by scaling down the Z point design to provide the first experimental data on MagLIF scaling. OMEGA delivers roughly 1000× less energy than Z, so target linear dimensions are reduced by factors of ~10. Magneto-inertial fusion electrical discharge system could provide an axial magnetic field of 10 T. Two-dimensional hydrocode modeling indicates that a single OMEGA beam can preheat the fuel to a mean temperature of ~200 eV, limited by mix caused by heat flow into the wall. One-dimensional magnetohydrodynamic (MHD) modelingmore » is used to determine the pulse duration and fuel density that optimize neutron yield at a fuel convergence ratio of roughly 25 or less, matching the Z point design, for a range of shell thicknesses. A relatively thinner shell, giving a higher implosion velocity, is required to give adequate fuel heating on OMEGA compared to Z because of the increase in thermal losses in smaller targets. Two-dimensional MHD modeling of the point design gives roughly a 50% reduction in compressed density, temperature, and magnetic field from 1-D because of end losses. Finally, scaling up the OMEGA point design to the MJ laser energy available on the National Ignition Facility gives a 500-fold increase in neutron yield in 1-D modeling.« less

  1. Laser-driven magnetized liner inertial fusion

    NASA Astrophysics Data System (ADS)

    Davies, J. R.; Barnak, D. H.; Betti, R.; Campbell, E. M.; Chang, P.-Y.; Sefkow, A. B.; Peterson, K. J.; Sinars, D. B.; Weis, M. R.

    2017-06-01

    A laser-driven, magnetized liner inertial fusion (MagLIF) experiment is designed for the OMEGA Laser System by scaling down the Z point design to provide the first experimental data on MagLIF scaling. OMEGA delivers roughly 1000× less energy than Z, so target linear dimensions are reduced by factors of ˜10. Magneto-inertial fusion electrical discharge system could provide an axial magnetic field of 10 T. Two-dimensional hydrocode modeling indicates that a single OMEGA beam can preheat the fuel to a mean temperature of ˜200 eV, limited by mix caused by heat flow into the wall. One-dimensional magnetohydrodynamic (MHD) modeling is used to determine the pulse duration and fuel density that optimize neutron yield at a fuel convergence ratio of roughly 25 or less, matching the Z point design, for a range of shell thicknesses. A relatively thinner shell, giving a higher implosion velocity, is required to give adequate fuel heating on OMEGA compared to Z because of the increase in thermal losses in smaller targets. Two-dimensional MHD modeling of the point design gives roughly a 50% reduction in compressed density, temperature, and magnetic field from 1-D because of end losses. Scaling up the OMEGA point design to the MJ laser energy available on the National Ignition Facility gives a 500-fold increase in neutron yield in 1-D modeling.

  2. Clinical effects of acrylic resilient denture liners applied to mandibular complete dentures on the alveolar ridge.

    PubMed

    Kimoto, S; Kimoto, K; Gunji, A; Kawai, Y; Murakami, H; Tanaka, K; Syu, K; Aoki, H; Toyoda, M; Kobayashi, K

    2007-11-01

    The purpose of this study was to investigate whether resilient denture liners has the potential to decrease problems affecting the alveolar ridge mucosa during the first adjustment session following the initial fitting of the denture. Interventions were complete denture treatment with permanent acrylic resilient denture liner dentures (RLD) in mandibles and conventional heat-activated acrylic resin dentures (ARD) in mandibles. Maxillary dentures were fabricated with conventional heat-activated ARD. Seventy-four subjects were randomly allocated to the RLD and ARD groups by random permuted blocks within the strata method after obtaining written informed consent. A randomized controlled parallel clinical trial with two hospital centres was conducted from April 2004 to July 2006. The problems were comprehensively evaluated by three outcomes with subjective and objective factors as follows: (i) numbers of sore spots, (ii) duration of wearing dentures and (iii) pain perception with 100 mm Visual Analog Scale. The numbers of sore spots in the mandibular support and border areas for the RLD group were significantly less than those for the ARD groups (P < 0.05). The RLD wearers were able to wear their dentures an additional day longer than the ARD wearers (P < 0.05). The maxillary and mandibular pain ratings for the RLD group were significantly lower than those for the ARD group (P < 0.05). Application of resilient denture liners to mandibular complete dentures provided edentulous patients with fewer problems affecting the alveolar during the first adjustment session following the initial fitting of the denture when compared with conventional denture treatments.

  3. Probing off-Hugoniot states in Ta, Cu, and Al to 1000 GPa compression with magnetically driven liner implosions

    SciTech Connect

    Lemke, R. W. Dolan, D. H.; Dalton, D. G.; Brown, J. L.; Robertson, G. R.; Harding, E.; Mattsson, A. E.; Carpenter, J. H.; Drake, R. R.; Cochrane, K.; Robinson, A. C.; Mattsson, T. R.; Tomlinson, K.; Blue, B. E.; Knudson, M. D.

    2016-01-07

    We report on a new technique for obtaining off-Hugoniot pressure vs. density data for solid metals compressed to extreme pressure by a magnetically driven liner implosion on the Z-machine (Z) at Sandia National Laboratories. In our experiments, the liner comprises inner and outer metal tubes. The inner tube is composed of a sample material (e.g., Ta and Cu) whose compressed state is to be inferred. The outer tube is composed of Al and serves as the current carrying cathode. Another aluminum liner at much larger radius serves as the anode. A shaped current pulse quasi-isentropically compresses the sample as it implodes. The iterative method used to infer pressure vs. density requires two velocity measurements. Photonic Doppler velocimetry probes measure the implosion velocity of the free (inner) surface of the sample material and the explosion velocity of the anode free (outer) surface. These two velocities are used in conjunction with magnetohydrodynamic simulation and mathematical optimization to obtain the current driving the liner implosion, and to infer pressure and density in the sample through maximum compression. This new equation of state calibration technique is illustrated using a simulated experiment with a Cu sample. Monte Carlo uncertainty quantification of synthetic data establishes convergence criteria for experiments. Results are presented from experiments with Al/Ta, Al/Cu, and Al liners. Symmetric liner implosion with quasi-isentropic compression to peak pressure ∼1000 GPa is achieved in all cases. These experiments exhibit unexpectedly softer behavior above 200 GPa, which we conjecture is related to differences in the actual and modeled properties of aluminum.

  4. Making a Metal-Lined Composite-Overwrapped Pressure Vessel

    NASA Technical Reports Server (NTRS)

    DeLay, Tom

    2005-01-01

    process has been devised for the fabrication of a pressure vessel that comprises a composite-material (matrix/fiber) shell with a metal liner on its inner surface. The use of the composite material makes it possible for the tank to be strong enough to withstand the anticipated operating pressure and yet weigh less than does an equivalent all-metal tank. The metal liner is used as a barrier against permeation: In the absence of such a barrier, the pressurized gas in the tank could leak by diffusing through the composite-material shell. The figure depicts workpieces at four key stages in the process, which consists of the following steps: 1. A mandrel that defines the size and shape of the pressure vessel is made by either molding or machining a piece of tooling wax. 2. Silver paint is applied to the surface of the mandrel to make it electrically conductive. 3. The ends of the mandrel are fitted with metal bosses. 4. The mandrel is put into a plating bath, wherein the metal liner is electrodeposited. Depending on the applications, the liner metal could be copper, nickel, gold, or an alloy. Typical liner thicknesses range from 1 to 10 mils (0.025 to 0.25 mm). 5. The wax is melted from within, leaving the thin metal liner. 6. A hollow shaft that includes holes and fittings through which the liner can be pressurized is sealed to both ends of the liner. The liner is pressurized to stiffen (and hence stabilize) it for the next step. 7. The pressurized liner is placed in a filament-winding machine, which is then operated to cover the liner with multiple layers of an uncured graphite-fiber/epoxy-matrix or other suitable composite material. 8. The composite-overwrapped liner is cured in an oven. 9. The pressure is relieved and the shaft is removed. The tank is then ready for use. The process as described above accommodates variations: a) The mandrel could be made of a wax that melts at a higher temperature and not removed until the tank is cured in the oven. b) The tank need

  5. GuideLiner Balloon Assisted Tracking (GBAT): A New Addition to the Interventional Toolbox

    PubMed Central

    Elbarouni, Basem; Moussa, Motaz; Kass, Malek; Toleva, Olga; Vo, Minh

    2016-01-01

    The use of guide extension catheters, such as GuideLiner, allows for increased guide support and facilitates device delivery in tortuous vessels. In cases which the GuideLiner catheter cannot be advanced even with balloon anchoring technique, we inflate a noncompliant balloon protruding from the GuideLiner catheter at nominal pressure and both the GuideLiner and the balloon are advanced over the coronary guidewire through the tortuous segments. This technique can be applied to 5.5 Fr., 6 Fr., and 7 Fr. GuideLiner catheters. This technique is termed GuideLiner Balloon Assisted Tracking (GBAT). PMID:28116176

  6. Detection of compact ultraviolet nuclear emission in liner galaxies

    NASA Technical Reports Server (NTRS)

    Maoz, Dan; Filippenko, Alexei V.; Ho, Luis C.; Rix, Hans-Walter; Bahcall, John N.; Schneider, Donald P.; Macchetto, F. Duccio

    1995-01-01

    Low-ionization nuclear emission-line regions (LINERs), which exist in a large fraction of galaxies, may be the least luminous manifestation of quasar activity. As such, they may make possible the study of the active galactic nucleus (AGN) phenomenon in the nearest galaxies. The nature of LINERs has, however, remained controversial because an AGN-like nonstellar continuum source has not been directly observed in them. We report the detection of bright (greater than or approximately = 2 x 10(exp -16) ergs/s/sq cm/A), unresolved (full width at half maximum (FWHM) less than or approximately = 0.1 sec) point sources of UV (approximately 2300 A) emission in the nuclei of nine nearby galaxies. The galaxies were imaged using the Faint Object Camera (FOC) on the Hubble Space Telescope (HST), and seven of them are from a complete sample of 110 nearby galaxies that was observed with HST. Ground-based optical spectroscopy reveals that five of the nuclei are LINERs, three are starburst nuclei, and one is a Seyfert nucleus. The observed UV flux in each of the five LINERs implies an ionizing flux that is sufficient to account to the observed emission lines through photoionization. The detection of a strong UV continuum in the LINERs argues against shock excitation as the source of the observed emission lines, and supports the idea that photoionization excites the lines in at least some objects of this class. We have analyzed ground-based spectra for most of the northern-hemisphere galaxies in the HST sample and find that 26 of them are LINERs, among which only the above five LINERs have a detected nuclear UV source.

  7. Self-assembly of Terbium(III)-based metal-organic complexes with two-photon absorbing active.

    PubMed

    Li, Dandan; Shao, Nanqi; Sun, Xianshun; Zhang, Guocui; Li, Shengli; Zhou, Hongping; Wu, Jieying; Tian, Yupeng

    2014-12-10

    Hybrid complexes based on D-π-A type dyes p-aminostyryl-pyridinum and Terbium(III) complex anion (1, 2) have been synthesized by ionic exchange reaction. Meanwhile two different alkyl-substituted amino groups were used as electron donors in organic dyes cations. The synthesized complexes were characterized by element analysis. In addition, the structural features of them were systematic studied by single crystal X-ray diffraction analysis. Their linear properties have been systematically investigated by absorption spectra and fluorescence, the results show that the energy transfer takes place from the trans-4-[4'-(N,N-diethylamino)styryl]-N-methyl pyridinium (2') cation to Tb(III). In addition, complex 2 exhibit a large two-photon absorption coefficient β: 0.044cm/GW at 710nm. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Flow of the current along metallic shunts in ohmic contacts to wide-gap III-V semiconductors

    SciTech Connect

    Blank, T. V. Goldberg, Yu. A.; Posse, E. A.

    2009-09-15

    It is established experimentally that the contact metal-wide-gap semiconductor (GaAs, GaP, GaN) with the Schottky barrier transforms into the ohmic contact either in the process of continuous heating or in the process of holding at an elevated temperature before the formation of any recrystallized layers. In this case, resistance of the contact reduced to the unit area increases as the temperature increases for semiconductors with a high dislocation density (GaP, GaN). It is assumed that in such contacts, the current flows along the metallic shunts, which shorten the layer of space charge and are formed by metal atoms diffused along the dislocation lines or other imperfections of the semiconductor. In semiconductors with a low dislocation density (GaAs), resistance of the ohmic contact per unit area decreases with increasing the temperature as it was expected for the thermionic mechanism of current flowing.

  9. Cementation of an acetabular liner into a well-fixed acetabular shell during revision total hip arthroplasty.

    PubMed

    Springer, Bryan D; Hanssen, Arlen D; Lewallen, David G

    2003-10-01

    Cementing a polyethylene liner into a well-fixed acetabular shell during revision hip arthroplasty may be appropriate in select patients. The purpose of this study was to review our early results with this technique. Sixteen patients with >2-year follow-up or who had any complications at <2 years from surgery were identified. Indications for this technique included: failure of the previous locking mechanism, significant polyethylene wear, malposition of the well-fixed metal shell, and previous removal of the liner with a retained acetabular shell. One acetabular shell has been revised at 13 months for multiple dislocations. Hip scores improved an average of 24.2 points. Radiographs revealed no polyethylene dissociation or acetabular loosening. Complications occurred in 7 patients. Initial results appear successful at providing secure fixation, while preventing the bone loss that might occur with removal of a well-fixed component.

  10. Mixed chloride/phosphine complexes of the dirhenium core. 10. Redox reactions of an edge-sharing dirhenium(III) non-metal-metal-bonded complex, Re(2)(mu-Cl)(2)Cl(4)(PMe(3))(4).

    PubMed

    Cotton, F A; Dikarev, E V; Petrukhina, M A

    2001-12-17

    Reduction and oxidation reactions of the dirhenium(III) non-metal-metal-bonded edge-sharing complex, Re(2)(mu-Cl)(2)Cl(4)(PMe(3))(4) (1), have been studied. Several new mono- and dinuclear rhenium compounds have been isolated and structurally characterized in the course of this study. Reductions of 1 with 1 and 2 equiv of KC(8) result in an unusual face-sharing complex having an Re(2)(5+) core, Re(2)(mu-Cl)(3)Cl(2)(PMe(3))(4) (2), and a triply bonded Re(II) compound, 1,2,7,8-Re(2)Cl(4)(PMe(3))(4) (3), respectively. Two-electron reduction of 1 in the presence of tetrabutylammonium chloride affords a new triply bonded complex of the Re(2)(4+) core, [Bu(n)()(4)N][1,2,7-Re(2)Cl(5)(PMe(3))(3)] (4). Oxidation of 1 with NOBF(4) yields a Re(IV) mononuclear compound, trans-ReCl(4)(PMe(3))(2) (5). Two isomers of the monomeric Re(III) anion, [ReCl(4)(PMe(3))(2)](-) (6, 7), have been isolated as side products. The crystal structures of compounds 2 and 4-7 have been determined by X-ray crystallography. The Re-Re distance in the face-sharing complex 2 of 2.686(1) A is relatively short. The metal-metal bond length in anion 4 of 2.2354(7) A is consistent with the usual values for the triply bonded Re(2)(4+) core compounds. In addition, a cis arrangement of trimethylphosphine ligands in the starting material 1 is retained upon reduction in the dinuclear products 2-4.

  11. An updated survey of globular clusters in M 31. III. A spectroscopic metallicity scale for the Revised Bologna Catalog

    NASA Astrophysics Data System (ADS)

    Galleti, S.; Bellazzini, M.; Buzzoni, A.; Federici, L.; Fusi Pecci, F.

    2009-12-01

    Aims. We present a new homogeneous set of metallicity estimates based on Lick indices for the old globular clusters of the M 31 galaxy. The final aim is to add homogeneous spectroscopic metallicities to as many entries as possible of the Revised Bologna Catalog of M 31 clusters, by reporting Lick index measurements from any source (literature, new observations, etc.) on the same scale. Methods: New empirical relations of [Fe/H] as a function of [MgFe] and Mg2 indices are based on the well-studied galactic globular clusters, complemented with theoretical model predictions for -0.2≤ [Fe/H]≤ +0.5. Lick indices for M 31 clusters from various literature sources (225 clusters) and from new observations by our team (71 clusters) have been transformed into the Trager et al. system, yielding new metallicity estimates for 245 globular clusters of M 31. Results: Our values are in good agreement with recent estimates based on detailed spectral fitting and with those obtained from color magnitude diagrams of clusters imaged with the Hubble Space Telescope. The typical uncertainty on individual estimates is ≃±0.25 dex, as resulted from the comparison with metallicities derived from color magnitude diagrams of individual clusters. Conclusions: The metallicity distribution of M 31 globular cluster is briefly discussed and compared with that of the Milky Way. Simple parametric statistical tests suggest that the distribution is probably not unimodal. The strong correlation between metallicity and kinematics found in previous studies is confirmed. The most metal-rich GCs tend to be packed into the center of the system and to cluster tightly around the galactic rotation curve defined by the HI disk, while the velocity dispersion about the curve increases with decreasing metallicity. However, also the clusters with [Fe/H]<-1.0 display a clear rotation pattern, at odds with their Milky Way counterparts. Based on observations made at La Palma, at the Spanish Observatorio del Roque

  12. Redox-inactive metal ions modulate the reactivity and oxygen release of mononuclear non-haem iron(III)–peroxo complexes

    DOE PAGES

    Bang, Suhee; Lee, Yong -Min; Hong, Seungwoo; ...

    2014-09-14

    Redox-inactive metal ions that function as Lewis acids play pivotal roles in modulating the reactivity of oxygen-containing metal complexes and metalloenzymes, such as the oxygen-evolving complex in photosystem II and its small-molecule mimics. Here we report the synthesis and characterization of non-haem iron(III)–peroxo complexes that bind redox-inactive metal ions, (TMC)FeIII–(μ,η2:η2-O2)–Mn+ (Mn+ = Sr2+, Ca2+, Zn2+, Lu3+, Y3+ and Sc3+; TMC, 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane). We demonstrate that the Ca2+ and Sr2+ complexes showed similar electrochemical properties and reactivities in one-electron oxidation or reduction reactions. However, the properties and reactivities of complexes formed with stronger Lewis acidities were found to be markedly different. Inmore » conclusion, complexes that contain Ca2+ or Sr2+ ions were oxidized by an electron acceptor to release O2, whereas the release of O2 did not occur for complexes that bind stronger Lewis acids. Furthermore, we discuss these results in the light of the functional role of the Ca2+ ion in the oxidation of water to dioxygen by the oxygen-evolving complex.« less

  13. X-Ray Emission Spectra and Electronic Structures of Red Phosphorus, 3d Transition-Metal Phosphides and III V Compounds

    NASA Astrophysics Data System (ADS)

    Sugiura, Chikara

    1995-07-01

    The P Kβ emission spectra in fluorescence from red amorphous phosphorus, 3d transition-metal phosphides TiP, CrP, FeP, Fe2P, Fe3P, CoP, Co2P, Ni5P4, Ni2P, Ni3P, Cu3P, ZnP2 (black) and Zn3P2, and the semiconducting phosphides of the III-V type, BP, AlP, GaP and InP are measured with a high-resolution two-crystal vacuum spectrometer equipped with Ge(111) crystals. The influence of the metal atoms appears distinctly on the P Kβ fluorescence emission spectra. The measured spectra are compared with available X-ray emission and XPS valence-band spectra and theoretical energy-band calculations on a common energy scale. It is shown that considerable p-d, s mixing occurs in the valence bands of the 3d transition-metal phosphides and the P 3p states mix fairly with the P 3s states in the valence bands of red phosphorus, Gap and InP

  14. Advanced Computational and Experimental Techniques for Nacelle Liner Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Jones, Michael G.; Brown, Martha C.; Nark, Douglas

    2009-01-01

    The Curved Duct Test Rig (CDTR) has been developed to investigate sound propagation through a duct of size comparable to the aft bypass duct of typical aircraft engines. The axial dimension of the bypass duct is often curved and this geometric characteristic is captured in the CDTR. The semiannular bypass duct is simulated by a rectangular test section in which the height corresponds to the circumferential dimension and the width corresponds to the radial dimension. The liner samples are perforate over honeycomb core and are installed on the side walls of the test section. The top and bottom surfaces of the test section are acoustically rigid to simulate a hard wall bifurcation or pylon. A unique feature of the CDTR is the control system that generates sound incident on the liner test section in specific modes. Uniform air flow, at ambient temperature and flow speed Mach 0.275, is introduced through the duct. Experiments to investigate configuration effects such as curvature along the flow path on the acoustic performance of a sample liner are performed in the CDTR and reported in this paper. Combinations of treated and acoustically rigid side walls are investigated. The scattering of modes of the incident wave, both by the curvature and by the asymmetry of wall treatment, is demonstrated in the experimental results. The effect that mode scattering has on total acoustic effectiveness of the liner treatment is also shown. Comparisons of measured liner attenuation with numerical results predicted by an analytic model based on the parabolic approximation to the convected Helmholtz equation are reported. The spectra of attenuation produced by the analytic model are similar to experimental results for both walls treated, straight and curved flow path, with plane wave and higher order modes incident. The numerical model is used to define the optimized resistance and reactance of a liner that significantly improves liner attenuation in the frequency range 1900-2400 Hz. A

  15. Boundary layer effects on liners for aircraft engines

    NASA Astrophysics Data System (ADS)

    Gabard, Gwénaël

    2016-10-01

    The performance of acoustic treatments installed on aircraft engines is strongly influenced by the boundary layer of the grazing flow on the surface of the liner. The parametric study presented in this paper illustrates the extent of this effect and identifies when it is significant. The acoustic modes of a circular duct with flow are calculated using a finite difference method. The parameters are representative of the flow conditions, liners and sound fields found in current turbofan engines. Both the intake and bypass ducts are considered. Results show that there is a complex interplay between the boundary layer thickness, the direction of propagation and the liner impedance and that the boundary layer can have a strong impact on liner performance for typical configurations (including changes of the order of 30 dB on the attenuation of modes associated with tonal fan noise). A modified impedance condition including the effect of a small but finite boundary layer thickness is considered and compared to the standard Myers condition based on an infinitely thin boundary layer. We show how this impedance condition can be implemented in a mode calculation method by introducing auxiliary variables. This condition is able to capture the trends associated with the boundary layer effects and in most cases provides improved predictions of liner performance.

  16. Scattering of acoustic duct modes by axial liner splices

    NASA Astrophysics Data System (ADS)

    Tam, Christopher K. W.; Ju, Hongbin; Chien, Eugene W.

    2008-03-01

    Recent engine test data and results of computational analysis show that the engine inlet acoustic liner splices have a significant impact on aircraft flight noise certification and cabin noise levels. The phenomenon of scattering of acoustic duct modes by axial liner splices is investigated. Previous studies, invariably, follow the frequency-domain approach. The present study, however, uses the time-domain approach. It is demonstrated that time-domain computation yields results that are in close agreement with frequency-domain results. The scattering phenomenon under consideration is very complex. This study concentrates on the effects of four parameters. They are the width of the splices, the frequency of the incident duct mode, the number of splices and the length of splices. Based on the computed results, the conditions under which scattered wave modes would significantly increase the intensity of transmitted waves are identified. It is also found that surface scattering by liner splices has the tendency to distribute energy equally to all the cut-on scattered azimuthal modes. On the other hand, for each scattered azimuthal mode, the high-order cut-on radial mode, generally, has the highest intensity. Moreover, scattering by liner splices is a local phenomenon. It is confined primarily to an area of the duct adjacent to the junction between the hard wall near the fan face and the spliced liner.

  17. Modeling of Passive Acoustic Liners from High Fidelity Numerical Simulations

    NASA Astrophysics Data System (ADS)

    Ferrari, Marcello do Areal Souto

    Noise reduction in aviation has been an important focus of study in the last few decades. One common solution is setting up acoustic liners in the internal walls of the engines. However, measurements in the laboratory with liners are expensive and time consuming. The present work proposes a nonlinear physics-based time domain model to predict the acoustic behavior of a given liner in a defined flow condition. The parameters of the model are defined by analysis of accurate numerical solutions of the flow obtained from a high-fidelity numerical code. The length of the cavity is taken into account by using an analytical procedure to account for internal reflections in the interior of the cavity. Vortices and jets originated from internal flow separations are confirmed to be important mechanisms of sound absorption, which defines the overall efficiency of the liner. Numerical simulations at different frequency, geometry and sound pressure level are studied in detail to define the model parameters. Comparisons with high-fidelity numerical simulations show that the proposed model is accurate, robust, and can be used to define a boundary condition simulating a liner in a high-fidelity code.

  18. Demonstration of a wireless, self-powered, electroacoustic liner system.

    PubMed

    Phipps, Alex; Liu, Fei; Cattafesta, Louis; Sheplak, Mark; Nishida, Toshikazu

    2009-02-01

    This paper demonstrates the system operation of a self-powered active liner for the suppression of aircraft engine noise. The fundamental element of the active liner system is an electromechanical Helmholtz resonator (EMHR), which consists of a Helmholtz resonator with one of its rigid walls replaced with a circular piezoceramic composite plate. For this system demonstration, two EMHR elements are used, one for acoustic impedance tuning and one for energy harvesting. The EMHR used for acoustic impedance tuning is shunted with a variable resistive load, while the EMHR used for energy harvesting is shunted to a flyback power converter and storage element. The desired acoustic impedance conditions are determined externally, and wirelessly transmitted to the liner system. The power for the receiver and the impedance tuning circuitry in the liner are supplied by the harvested energy. Tuning of the active liner is demonstrated at three different sound pressure levels (148, 151, and 153 dB) in order to show the robustness of the energy harvesting and storage system. An acoustic tuning range of approximately 200 Hz is demonstrated for each of the three available power levels.

  19. Analyses of a Reinforced Concrete Containment with Liner Corrosion Damage

    SciTech Connect

    Cherry, J.L.; Smith, J.A.

    1998-11-19

    Incidents of liner corrosion in nuclear power containment structures have been recorded. These incidents and concerns of other possible liner corrosion in containment have prompted an interest in determining g the capacity of a degraded containment. Finite element analyses of a typical pressurized water reactor (PWR) reinforced concrete containment with liner corrosion were conducted using the A13AQUS finite element code with the ANACAP-U nonlinear concrete constitutive model. The effect of liner corrosion on containment capacity was investigated. A loss of coolant accident was simulated by applying pressure and temperature changes to the structure without corrosion to determine baseline failure limits, followed by multiple analyses of the containment with corrosion at different locations and varying degrees of liner degradation. The corrosion locations were chosen at the base of the containment wall, near the equipment hatch, and at the midheight of the containment wall. Using a strain-based failure criterion the different scenarios were evaluated to prioritize their effect on containment capacity

  20. Metal Accretion onto White Dwarfs. III. A Still Better Approach Based on the Coupling of Diffusion with Evolution

    NASA Astrophysics Data System (ADS)

    Brassard, Pierre; Fontaine, Gilles

    2015-06-01

    The accretion-diffusion picture is the model par excellence for describing the presence of planetary debris polluting the atmospheres of relatively cool white dwarfs. In the time-dependent approach used in Paper II of this series (Fontaine et al. 2014), the basic assumption is that the accreted metals are trace elements and do not influence the background structure, which may be considered static in time. Furthermore, the usual assumption of instantaneous mixing in the convection zone is made. As part of the continuing development of our local evolutionary code, diffusion in presence of stellar winds or accretion is now fully coupled to evolution. Convection is treated as a diffusion process, i.e., the assumption of instantaneous mixing is relaxed, and, furthermore, overshooting is included. This allows feedback on the evolving structure from the accreting metals. For instance, depending of its abundance, a given metal may contribute enough to the overall opacity (especially in a He background) to change the size of the convection zone as a function of time. Our better approach also allows to include in a natural way the mechanism of thermohaline convection, which we discuss at some length. Also, it is easy to consider sophisticated time-dependent models of accretion from circumstellar disks, such as those developed by Roman Rafikov at Princeton for instance. The current limitations of our approach are 1) the calculations are extremely computer-intensive, and 2) we have not yet developed detailed EOS megatables for metals beyond oxygen.