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Sample records for aluminum foils interpreting

  1. Process for anodizing aluminum foil

    SciTech Connect

    Ball, J.A.; Scott, J.W.

    1984-11-06

    In an integrated process for the anodization of aluminum foil for electrolytic capacitors including the formation of a hydrous oxide layer on the foil prior to anodization and stabilization of the foil in alkaline borax baths during anodization, the foil is electrochemically anodized in an aqueous solution of boric acid and 2 to 50 ppm phosphate having a pH of 4.0 to 6.0. The anodization is interrupted for stabilization by passing the foil through a bath containing the borax solution having a pH of 8.5 to 9.5 and a temperature above 80/sup 0/ C. and then reanodizing the foil. The process is useful in anodizing foil to a voltage of up to 760 V.

  2. Chromic acid anodizing of aluminum foil

    NASA Technical Reports Server (NTRS)

    Dursch, H.

    1988-01-01

    The success of the Space Station graphite/epoxy truss structure depends on its ability to endure long-term exposure to the LEO environment, primarily the effects of atomic oxygen and the temperture cycling resulting from the 94 minute orbit. This report describes the development and evaluation of chromic acid anodized (CAA) aluminum foil as protective coatings for these composite tubes. Included are: development of solar absorptance and thermal emittance properties required of Al foil and development of CAA parameters to achieve these optical properties; developing techniques to CAA 25 ft lengths of Al foil; developing bonding processes for wrapping the Al foil to graphite/epoxy tubes; and atomic oxygen testing of the CAA Al foil. Two specifications were developed and are included in the report: Chromic Acid Anodizing of Aluminum Foil Process Specification and Bonding of Anodized Aluminum Foil to Graphite/Epoxy Tubes. Results show that CAA Al foil provides and excellent protective and thermal control coating for the Space Station truss structure.

  3. Effects of Aluminum Foil Packaging on Elemental Analysis of Bone.

    PubMed

    Lewis, Lyniece; Christensen, Angi M

    2016-03-01

    Burned skeletal material is often very fragile and at high risk for fragmentation during packaging and transportation. One method that has been suggested to protect bones in these cases is to carefully wrap them in aluminum foil. Traces of aluminum, however, are known to transfer from foil packaging materials to food products. If such transfer occurs between aluminum foil and bones, it could interfere with subsequent chemical, elemental and isotopic analyses, which are becoming more common in forensic anthropological investigations. This study examined aluminum levels in bones prior to and following the use of aluminum foil packaging and storage for a 6-week period. Results indicate no significant change in the detected levels of aluminum (p > 0.05), even when packaged in compromised foil and exposed to elevated temperatures. Aluminum foil can therefore continue to be recommended as a packaging medium without affecting subsequent chemical examinations.

  4. Recycling of waste of aluminum foil into sheet materials

    SciTech Connect

    Katashinskii, V.P.; Vishnyakov, L.R.; Boiko, P.A.

    1995-07-01

    The principal method of recycling secondary metals, in particular aluminum, is remelting. However, remelting of aluminum swarf, and in particular of foil trimmings, is marked by low effectiveness because of extensive oxidation (in the processing of thin foil loss by oxidation amounts to 80%), low productivity of the metallurgical equipment on account of low volume-weight characteristics of foil trimmings compared with lumpy scrap metal, and high power requirements of metallurgical conversion. The shortcomings of the traditional technology can be eliminated by recycling foil trimmings by methods of powder metallurgy. This eliminates completely remelting and loss of metal by oxidation, simplifies the technological cycle, and reduces power requirements. We investigated the process of recycling aluminum foil marque A6 (GOST 21631-76) 14 and 30 {mu}m thick which is widely used in the food industry. The amount of waste occurring in its production may attain 15% of the annual output. In the initial state the waste of foil for food are trimmings of thin aluminum strip crushed into fragments of arbitrary shape whose maximal size in plan is 5-8 cm. To be processed by methods of powder metallurgy, such waste has to be converted into smaller fragments that fill well the cavity of the die when pressed in closed molds or the deformation zone in rolling or other methods of compaction in open tools.

  5. Laser shock microforming of aluminum foil with fs laser

    NASA Astrophysics Data System (ADS)

    Ye, Yunxia; Feng, Yayun; Xuan, Ting; Hua, Xijun; Hua, Yinqun

    2014-12-01

    Laser shock microforming of Aluminum(Al) foil through fs laser has been researched in this paper. The influences of confining layer, clamping method and impact times on induced dent depths were investigated experimentally. Microstructure of fs laser shock forming Al foil was observed through Transmission electron microscopy (TEM). Under the condition of tightly clamping, the dent depths increase with impact times and finally tend to saturating. Another new confining layer, the main component of which is polypropylene, was applied and the confining effect of it is better because of its higher impedance. TEM results show that dislocation is one of the main deformation mechanisms of fs laser shock forming Al foil. Specially, most of dislocations exist in the form of short and discrete dislocation lines. Parallel straight dislocation slip line also were observed. We analyzed that these unique dislocation arrangements are due to fs laser-induced ultra high strain rate.

  6. 75 FR 1596 - Grant of Authority for Subzone Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-12

    ... (Aluminum Foil Liner Stock), Louisville, Kentucky Pursuant to its authority under the Foreign-Trade Zones... to the Board for authority to establish a special-purpose subzone at the aluminum foil liner stock... status for activity related to the manufacturing and distribution of aluminum foil liner stock...

  7. Using Aluminum Foil to Record Structures in Sedimentary Rock.

    ERIC Educational Resources Information Center

    Metz, Robert

    1982-01-01

    Aluminum foil can be used to make impressions of structures preserved in sedimentary rock. The impressions can be projected onto a screen, photographed, or a Plaster of Paris model can be made from them. Impressions of ripple marks, mudcracks, and raindrop impressions are provided in photographs illustrating the technique. (Author/JN)

  8. Electrospray ionization with aluminum foil: A versatile mass spectrometric technique.

    PubMed

    Hu, Bin; So, Pui-Kin; Yao, Zhong-Ping

    2014-03-19

    In this study, we developed a novel electrospray ionization (ESI) technique based on household aluminum foil (Al foil) and demonstated the desirable features and applications of this technique. Al foil can be readily cut and folded into desired configuration for effective ionization and for holding sample solution in bulk to allowing acquisition of durable ion signals. The present technique was demonstrated to be applicable in analysis of a wide variety of samples, ranging from pure chemical and biological compounds, e.g., organic compounds and proteins, to complex samples in liquid, semi-solid, and solid states, e.g., beverages, skincare cream, and herbal medicines. The inert, hydrophobic and impermeable surface of Al foil allows convenient and effective on-target extraction of solid samples and on-target sample clean-up, i.e., removal of salts and detergents from proteins and peptides, extending ESI device from usually only for sample loading and ionization to including sample processing. Moreover, Al foil is an excellent heat-conductor and highly heat-tolerant, permitting direct monitoring of thermal reactions, e.g., thermal denaturation of proteins. Overall, the present study showed that Al-foil ESI could be an economical and versatile method that allows a wide range of applications.

  9. Reduction of Viologen Bisphosphonate Dihalide with Aluminum Foil

    NASA Astrophysics Data System (ADS)

    Abeta Iyere, Peter

    1996-05-01

    An elegant undergraduate experiment similar to the popular "Iodine Clock Reaction" employs the reduction of methyl viologen by hydroxide ion. A major problem with the hydroxide reduction demonstration is that the mechanism is complicated by the existence of competing reaction pathways. It has been suggested that layered metal viologen phosphonates could be used in the design and construction of molecular materials. The active unit in the reversible photocoloration of these layered materials is the viologen bisphosphonate dihalide (VPX). During our study of these phoshponate systems, we discovered the reduction of viologen bisphosphonate dihalide by aluminum foil, mossy zinc, or magnesium turnings in dilute aqueous hydrofluoric acid solution. When we demonstrated this phenomenon with aluminum foil and VPBr in the classroom, the response of our students was enthusiastic. This demonstration can be used as prelaboratory discussion for an undergraduate kinetic experiment based on the same phenomenon.

  10. Analysis of peel strength of consisting of an aluminum sheet, anodic aluminum oxide and a copper foil laminate composite

    NASA Astrophysics Data System (ADS)

    Shin, Hyeong-Won; Lee, Hyo-Soo; Jung, Seung-Boo

    2017-01-01

    Laminate composites consisting of an aluminum sheet, anodic aluminum oxide, and copper foil have been used as heat-spreader materials for high-power light-emitting diodes (LEDs). These composites are comparable to the conventional structure comprising an aluminum sheet, epoxy adhesives, and copper foil. The peel strength between the copper foil and anodic aluminum oxide should be more than 1.0 kgf/cm in order to be applied in high-power LED products. We investigated the effect of the anodic aluminum oxide morphology and heat-treatment conditions on the peel strength of the composites. We formed an anodic aluminum oxide layer on a 99.999% pure aluminum sheet using electrochemical anodization. A Ti/Cu seed layer was formed using the sputtering direct bonding copper process in order to form a copper circuit layer on the anodic aluminum oxide layer by electroplating. The developed heat spreader, composed of an aluminum layer, anodic aluminum oxide, and a copper circuit layer, showed peel strengths ranging from 1.05 to 3.45 kgf/cm, which is very suitable for high-power LED applications.

  11. Interpretation of aluminum-alloy weld radiography

    NASA Technical Reports Server (NTRS)

    Duren, P. C.; Risch, E. R.

    1971-01-01

    Report proposes radiographic terminology standardization which allows scientific interpretation of radiographic films to replace dependence on individual judgement and experience. Report includes over 50 photographic pages where radiographs of aluminum welds with defects are compared with prepared weld sections photomacrographs.

  12. Application of aluminum and titanium foils in low-energy wide-aperture electron accelerators

    NASA Astrophysics Data System (ADS)

    Bodakin, L. V.; Gusakov, A. I.; Komarov, O. V.; Kosogorov, S. L.; Motovilov, S. A.; Uspenskii, N. A.

    2016-09-01

    We have reported on the results of theoretical and experimental investigations of characteristics of aluminum and titanium foils used in devices to extract electron beams from wide-aperture low-energy accelerators with a high current density. The mechanical properties of foils at different temperatures and the electron beam transmission and absorption coefficients have been compared. The results of analyzing the dependences of the efficiency of the electron beam extraction from accelerators on the type of the electron-optical system, material, and thickness of the foil for various sizes of extraction windows and the same type of the slot support grids have been presented. We have proposed an analytic model for calculating the temperature of the foil in the unit cell of the support grid. The electron transmittance and absorbance, as well as the temperature regimes of the foils, have been calculated using different methods.

  13. Thermally-induced stresses in graphite-epoxy tubes coated with aluminum foil

    NASA Technical Reports Server (NTRS)

    Knott, Tamara W.; Hyer, M. W.

    1989-01-01

    Thermally-induced stresses in the foil, adhesive, and graphite-epoxy layers of composite tubes with aluminum foil bonded to the inner and outer surface are computed. The thermal effects are due to a temperature decrease from the processing temperature of the material to a temperature felt to represent the space environment, the intended operating environment of the tubes. Tubes fabricated from T300/934 and P75s/934 material systems are considered. The results indicate that the presence of the foil and adhesive have no detrimental effect on the stresses in the tube.

  14. Formation and evolution of tweed structures on high-purity aluminum polycrystalline foils under cyclic tension

    SciTech Connect

    Kuznetsov, P. V.; Vlasov, I. V.; Sklyarova, E. A.; Smekalina, T. V.

    2015-10-27

    Peculiarities of formation and evolution of tweed structures on the surface of high-purity aluminum polycrystalline foils under cyclic tension were studied using an atom force microscope and a white light interferometer. Tweed structures of micron and submicron sizes were found on the foils at different number of cycles. In the range of 42,000 < N < 95,000 cycles destruction of tweed patterns is observed, which leads to their disappearance from the surface of the foils. Formation of tweed structures of various scales is discussed in terms of the Grinfeld instability.

  15. Light protection of fiber-reinforced strip using aluminum foil for the direct splinting technique.

    PubMed

    Anagnostou, M; Papazoglou, Efstratios; Mountouris, G; Gaintantzopoulou, M

    2006-01-01

    The critical point of the clinical procedure of direct splinting is the placement of the fiber-reinforced strip, which has to be well adapted to tooth surfaces. This article describes the use of aluminum foil to cover and protect the fiber-reinforced strip from light polymerization during the direct splinting technique. The advantage of using aluminum foil is to prevent premature curing of the fiber-reinforced strip, which would necessitate repetition of the procedure. With this technique, the strip is gradually exposed and adapted to the lingual/palatal surfaces of the teeth and light cured, allowing for ample working time.

  16. Roll-to-roll anodization and etching of aluminum foils for high-throughput surface nanotexturing.

    PubMed

    Lee, Min Hyung; Lim, Namsoo; Ruebusch, Daniel J; Jamshidi, Arash; Kapadia, Rehan; Lee, Rebecca; Seok, Tae Joon; Takei, Kuniharu; Cho, Kee Young; Fan, Zhiyoung; Jang, Hwanung; Wu, Ming; Cho, Gyoujin; Javey, Ali

    2011-08-10

    A high-throughput process for nanotexturing of hard and soft surfaces based on the roll-to-roll anodization and etching of low-cost aluminum foils is presented. The process enables the precise control of surface topography, feature size, and shape over large areas thereby presenting a highly versatile platform for fabricating substrates with user-defined, functional performance. Specifically, the optical and surface wetting properties of the foil substrates were systematically characterized and tuned through the modulation of the surface texture. In addition, textured aluminum foils with pore and bowl surface features were used as zeptoliter reaction vessels for the well-controlled synthesis of inorganic, organic, and plasmonic nanomaterials, demonstrating yet another powerful potential use of the presented approach.

  17. Recycling of aluminum foil from post-consumer beverage cartons

    SciTech Connect

    Charlier, P.; Sjoeberg, G.

    1995-12-31

    Recycling of aluminium contained in used aseptic beverage cartons is a difficult task which has nevertheless to be tackled by modern societies. Techniques have earlier been developed by the paper and pulp industry for the recycling of the board fibers from collected post-consumer beverage cartons. A joint technical feasibility study by Graenges and a leading beverage carton producer has dealt with different techniques for handling residues from repulsing facilities. The aluminium obtained can be used as raw material for the production of thin gauge foil, thus closing the recycling loop.

  18. TOF-SIMS Analysis of Crater Residues from Wild 2 Cometary on Stardust Aluminum Foil

    NASA Technical Reports Server (NTRS)

    Leutner, Jan; Stephan, Thomas; Kearsley, T.; Horz, Friedrich; Flynn, George J.; Sandford, Scott A.

    2006-01-01

    Impact residues of cometary particles on aluminum foils from the Stardust mission were investigated with TOF-SIMS for their elemental and organic composition. The residual matter from comet 81P/Wild 2 shows a wide compositional range, from nearly monomineralic grains to polymict aggregates. Despite the comparably small analyzed sample volume, the average element composition of the investigated residues is similar to bulk CI chondritic values. Analysis of organic components in impact residues is complicated, due to fragmentation and alteration of the compounds during the impact process and by the presence of contaminants on the aluminum foils. Nevertheless, polycyclic aromatic hydrocarbons (PAHs) that are unambiguously associated with the impact residues were observed, and thus are most likely of cometary origin.

  19. Ultrasonic effect on etching tunnel morphology and distribution of aluminum foil

    NASA Astrophysics Data System (ADS)

    Hu, Bin; Sun, Yanzi; Guan, Bing; Zhao, Jing; Zhang, Huaihao; Zhu, Deqiu; Ma, Kunsong; Cheng, Changjing

    2017-01-01

    Etching aluminum foil was prepared by electrochemical DC etching under ultrasonic superimposition. Specifically, the relationship of electrochemical behavior, interface behavior and mass transfer enhancement from ultrasound was investigated intensively by chronopotentiometry, potentiodynamic polarization, cyclic voltammetry and electrochemical impedance spectra. Meanwhile, the etching specimens were characterized by SEM, N2 adsorption and XRD patterns measurements. The results showed that ultrasonic agitation inhibited the growth of aluminum oxide film and facilitated pit initiation effectively via increasing the Cl- adsorption on electrolyte/aluminum oxide film interface, and strengthened the inward/outward migration of Cl- and AlCl3 within tunnels by thinning the thickness of diffusion layer and decreasing the electrolyte resistance. Moreover, the double layer capacitance Cdl, pit density, average pit size/tunnel length and its homogeneity are all enhanced under ultrasonic superimposition.

  20. Analysis of Cometary Dust Impact Residues in the Aluminum Foil Craters of Stardust

    NASA Technical Reports Server (NTRS)

    Graham, G. A.; Kearsley, A. T.; Vicenzi, E. P.; Teslich, N.; Dai, Z. R.; Rost, D.; Horz, F.; Bradley, J. P.

    2007-01-01

    In January 2006, the sample return capsule from NASA s Stardust spacecraft successfully returned to Earth after its seven year mission to comet Wild-2. While the principal capture medium for comet dust was low-density graded silica aerogel, the 1100 series aluminum foil (approximately 100 m thick) which wrapped around the T6064 aluminum frame of the sample tray assembly (STA) contains micro-craters that constitute an additional repository for Wild-2 dust. Previous studies of similar craters on spacecraft surfaces, e.g. the Long Duration Exposure Facility (LDEF), have shown that impactor material can be preserved for elemental and mineralogical characterization, although the quantity of impact residue in Stardust craters far exceeds previous missions. The degree of shock-induced alteration experienced by the Wild-2 particles impacting on foil will generally be greater than for those captured in the low-density aerogel. However, even some of the residues found in LDEF craters showed not only survival of crystalline silicates but even their solar flare tracks, which are extremely fragile structures and anneal at around 600 C. Laboratory hypervelocity experiments, using analogues of Wild-2 particles accelerated into flight-grade foils under conditions close to those of the actual encounter, showed retention of abundant projectile residues at the Stardust encounter velocity of 6.1 km/s. During the preliminary examination (PE) of the returned foils, using optical and electron microscopy studies, a diverse range in size and morphologies of micro-craters was identified. In this abstract we consider the state of residue preservation in a diverse range of craters with respect to their elemental composition and inferred mineralogy of the original projectiles.

  1. Investigation of various criteria for evaluation of aluminum thin foil ''smart sensors'' images

    NASA Astrophysics Data System (ADS)

    Panin, S. V.; Eremin, A. V.; Lyubutin, P. S.; Burkov, M. V.

    2014-10-01

    Various criteria for processing of aluminum foil ''smart sensors'' images for fatigue evaluation of carbon fiber reinforced polymer (CFRP) were analyzed. There are informative parameters used to assess image quality and surface relief and accordingly to characterize the fatigue damage state of CFRP. The sensitivity of all criteria to distortion influences, particularly, to Gaussian noise, blurring and JPEG compression was investigated. The main purpose of the research is related to the search of informative parameters for fatigue evaluation, which are the least sensitive to different distortions.

  2. Numerical modeling of large-area beta sources constructed from anodized-aluminum foils.

    PubMed

    Stanga, D

    2012-09-01

    The numerical modeling of large-area beta sources constructed from anodized-aluminum foils is described in this paper. Based on a realistic model for the activity depth distribution, theoretical lower and upper bounds for the efficiency and the transmission coefficient were calculated and used to analyze the comparison method recommended by ISO 8769 for measuring the surface emission rate. The analysis shows that this method can provide measurement results with relative standard uncertainties smaller than 3% for high energy beta emitters such as (90)Sr-(90)Y, (36)Cl and (204)Tl.

  3. The Use of SYMLOG as an Interpretive Foil for Participant Observer Research in Organizations.

    ERIC Educational Resources Information Center

    Savage, Grant T.

    In addition to assessing observed communication behaviors, this paper suggests that SYMLOG--a System for the Multiple Level Observation of Groups--can be used by participant-observers as a foil for interpreting how their own value orientations affect their data collecting and theorizing. The first section of the paper examines the research role…

  4. Preparation of titanium dioxide films on etched aluminum foil by vacuum infiltration and anodizing

    NASA Astrophysics Data System (ADS)

    Xiang, Lian; Park, Sang-Shik

    2016-12-01

    Al2O3-TiO2 (Al-Ti) composite oxide films are a promising dielectric material for future use in capacitors. In this study, TiO2 films were prepared on etched Al foils by vacuum infiltration. TiO2 films prepared using a sol-gel process were annealed at various temperatures (450, 500, and 550 °C) for different time durations (10, 30, and 60 min) for 4 cycles, and then anodized at 100 V. The specimens were characterized using X-ray diffraction, field emission scanning electron microscopy, and field emission transmission electron microscopy. The results show that the tunnels of the specimens feature a multi-layer structure consisting of an Al2O3 outer layer, an Al-Ti composite oxide middle layer, and an aluminum hydrate inner layer. The electrical properties of the specimens, such as the withstanding voltage and specific capacitance, were also measured. Compared to specimens without TiO2 coating, the specific capacitances of the TiO2-coated specimens are increased. The specific capacitance of the anode Al foil with TiO2 coating increased by 42% compared to that of a specimen without TiO2 coating when annealed at 550 °C for 10 min. These composite oxide films could enhance the specific capacitance of anode Al foils used in dielectric materials.

  5. Initiation of a discharge channel in water by means of electrical explosion of aluminum foil

    NASA Astrophysics Data System (ADS)

    Sil'nikov, M. V.; Krivosheev, S. I.; Kulakov, K. S.; Kulakov, S. L.

    2013-12-01

    This paper reports the results of an experimental investigation into initiation of the electric discharge in service water by means of explosion of aluminum foil having various mass and dimensions. The electric discharge was formed in a chamber with a movable wall (the piston). As an electric energy storage, the capacitor bank having the capacity C = 200-600 μF with charging voltage U 0 = 2-5 kV (stored energy Q 0 = 0.4-7.5 kJ) and the rate of rise of the discharging current dI/ dt = (3-4) × 109 A/s. The results of experiments showed that destruction (loss of conductivity) of foil occurs at the value of the integral of the current density h j = (0.3-0.65) × 109 (A2/cm4)/s. The stage of the repeated breakdown in the electric discharge occurs when the value of the intensity of the electric field along the discharge channel is of E rb ≥ 50 V/mm. Geometric dimensions and mass of the initiating conductor that provide the maximum efficiency of conversion of the value of Q 0 into kinetic energy of the piston have been determined.

  6. Application of aluminum foil for ``strain sensing'' at fatigue damage evaluation of carbon fiber composite

    NASA Astrophysics Data System (ADS)

    Panin, Sergey; Burkov, Mikhail; Lyubutin, Pavel; Altukhov, Yurii

    2014-01-01

    Surface layer of a loaded solid is an individual structural level of deformation that was shown numerously within concept of physical mesomechanics. This gives rise to advance in its deformation development under loading as well as allows using this phenomenon to sense the strain induced structure changes. It is of specific importance for composite materials since they are highly heterogeneous while estimating their mechanical state is a topical applied problem. Fatigue tests of carbon fiber composite specimens were carried out for cyclic deformation estimation with the use of strain sensors made of thin (80 μm) aluminum foil glued to the specimen's surface. The surface images were captured by DSLR camera mounted onto an optical microscope. Strain relief to form during cyclic loading was numerically estimated using different parameters: dispersion, mean square error, universal image quality index, fractal dimension and energy of Fourier spectrum. The results are discussed in view of deformation mismatch in thin foil and bulk specimen and are offered to be applied for the development of Structural Health Monitoring (SHM) approach.

  7. Classroom Foils

    ERIC Educational Resources Information Center

    Pafford, William N.

    1970-01-01

    Aluminum foil, because of its characteristics, can be used for many elementary science activities: demonstrating Archimedes Principle, how to reduce cohesion, reflection and mirror effect, fuse action, condensation, friction, and as containers and barriers. (BR)

  8. Fabrication and icing property of superhydrophilic and superhydrophobic aluminum surfaces derived from anodizing aluminum foil in a sodium chloride aqueous solution

    NASA Astrophysics Data System (ADS)

    Song, Meirong; Liu, Yuru; Cui, Shumin; Liu, Long; Yang, Min

    2013-10-01

    An aluminum foil with a rough surface was first prepared by anodic treatment in a neutral aqueous solution with the help of pitting corrosion of chlorides. First, the hydrophobic Al surface (contact angle around 79°) became superhydrophilic (contact angle smaller than 5°) after the anodizing process. Secondly, the superhydrophilic Al surface became superhydrophobic (contact angle larger than 150°) after being modified by oleic acid. Finally, the icing property of superhydrophilic, untreated, and superhydrophobic Al foils were investigated in a refrigerated cabinet at -12 °C. The mean total times to freeze a water droplet (6 μL) on the three foils were 17 s, 158 s and 1604 s, respectively. Thus, the superhydrophilic surface accelerates the icing process, while the superhydrophobic surface delays the process. The main reason for this transition might mainly result from the difference of the contact area of the water droplet with Al substrate: the increase in contact area with Al substrate will accelerate the heat conduct process, as well as the icing process; the decrease in contact area with Al substrate will delay the heat conduct process, as well as the icing process. Compared to the untreated Al foil, the contact area of the water droplet with the Al substrate was higher on superhydrophilic surface and smaller on the superhydrophobic surface, which led to the difference of the heat transfer time as well as the icing time.

  9. On-line measurements of proton beam current from a PET cyclotron using a thin aluminum foil

    NASA Astrophysics Data System (ADS)

    Ghithan, S.; do Carmo, S. J. C.; Ferreira Marques, R.; Fraga, F. A. F.; Simões, H.; Alves, F.; Crespo, P.

    2013-07-01

    The number of cyclotrons capable of accelerating protons to about 20 MeV is increasing throughout the world. Originally aiming at the production of positron emission tomography (PET) radionuclides, some of these facilities are equipped with several beam lines suitable for scientific research. Radiobiology, radiophysiology, and other dosimetric studies can be performed using these beam lines. In this work, we measured the Bragg peak of the protons from a PET cyclotron using a stacked target consisting of several aluminum foils interleaved with polyethylene sheets, readout by in-house made transimpedance electronics. The measured Bragg peak is consistent with simulations performed using the SRIM/TRIM simulation toolkit. Furthermore, we report on experimental results aiming at measuring proton beam currents down to 10 pA using a thin aluminum foil (20-μm-thick). The aluminum was chosen for this task because it is radiation hard, it has low density and low radiation activity, and finally because it is easily available at negligible cost. This method allows for calculating the dose delivered to a target during an irradiation with high efficiency, and with minimal proton energy loss and scattering.

  10. Investigation of the crater-like microdefects induced by laser shock processing with aluminum foil as absorbent layer

    NASA Astrophysics Data System (ADS)

    Ye, Y. X.; Xuan, T.; Lian, Z. C.; Feng, Y. Y.; Hua, X. J.

    2015-06-01

    This paper reports that 3D crater-like microdefects form on the metal surface when laser shock processing (LSP) is applied. LSP was conducted on pure copper block using the aluminum foil as the absorbent material and water as the confining layer. There existed the bonding material to attach the aluminum foil on the metal target closely. The surface morphologies and metallographs of copper surfaces were characterized with 3D profiler, the optical microscopy (OM) or the scanning electron microscopy (SEM). Temperature increases of metal surface due to LSP were evaluated theoretically. It was found that, when aluminum foil was used as the absorbent material, and if there existed air bubbles in the bonding material, the air temperatures within the bubbles rose rapidly because of the adiabatic compression. So at the locations of the air bubbles, the metal materials melted and micromelting pool formed. Then under the subsequent expanding of the air bubbles, a secondary shock wave was launched against the micromelting pool and produced the crater-like microdefects on the metal surface. The temperature increases due to shock heat and high-speed deformation were not enough to melt the metal target. The temperature increase induced by the adiabatic compression of the air bubbles may also cause the gasification of the metal target. This will also help form the crater-like microdefects. The results of this paper can help to improve the surface quality of a metal target during the application of LSP. In addition, the results provide another method to fabricate 3D crater-like dents on metal surface. This has a potential application in mechanical engineering.

  11. SIMS Studies of Allende Projectiles Fired into Stardust-type Aluminum Foils at 6 km/s

    NASA Technical Reports Server (NTRS)

    Hoppe, Peter; Stadermann, Frank J.; Stephan, Thomas; Floss, Christine; Leitner, Jan; Marhas, Kuljeet; Horz, Friedrich

    2006-01-01

    We have explored the feasibility of C-, N-, and O-isotopic measurements by NanoSIMS and of elemental abundance determinations by TOF-SIMS on residues of Allende projectiles that impacted Stardust-type aluminum foils in the laboratory at 6 km/s. These investigations are part of a consortium study aimed at providing the foundation for the characterization of matter associated with micro-craters that were produced during the encounter of the Stardust space probe with comet 81P/Wild 2. Eleven experimental impact craters were studied by NanoSIMS and eighteen by TOF-SIMS. Crater sizes were between 3 and 190 microns. The NanoSIMS measurements have shown that the crater morphology has only a minor effect on spatial resolution and on instrumental mass fractionation. The achievable spatial resolution is always better than 200 nm, and C- and O-isotopic ratios can be measured with a precision of several percent at a scale of several 100 nm, the typical size of presolar grains. This clearly demonstrates that presolar matter, provided it survives the impact into the aluminum foil partly intact, is recognizable even if embedded in material of Solar System origin. TOF-SIMS studies are restricted to materials from the crater rim. The element ratios of the major rockforming elements in the Allende projectiles are well characterized by the TOF-SIMS measurements, indicating that fractionation of those elements during impact can be expected to be negligible. This permits information on the type of impactor material to be obtained. For any more detailed assignments to specific chondrite groups, however, information on the abundances of the light elements, especially C, is crucial.

  12. Improvement of Transverse Strength in Graphite-Aluminum Composites by High-Strength Surface Foils.

    DTIC Science & Technology

    1982-02-01

    purchased from Material Concepts Incorporated. The precursor wire had Union Carbide’s VSB-32 or VS0054 pitch mesophase graphite fibers in a matrix of...probably valid. The reason for the low strength of these plates, particularly G4407, is not known. Pitch fiber graphite-aluminum composites usually have

  13. Prediction and characterization of heat-affected zone formation due to neighboring nickel-aluminum multilayer foil reaction

    SciTech Connect

    Adams, David P.; Hirschfeld, Deidre A.; Hooper, Ryan J.; Manuel, Michelle V.

    2015-09-01

    Reactive multilayer foils have the potential to be used as local high intensity heat sources for a variety of applications. Much of the past research effort concerning these materials have focused on understanding the structure-property relationships of the foils that govern the energy released during a reaction. To enhance the ability of researchers to more rapidly develop technologies based on reactive multilayer foils, a deeper and more predictive understanding of the relationship between the heat released from the foil and microstructural evolution in the neighboring materials is needed. This work describes the development of a numerical model for the purpose of evaluating new foil-substrate combinations for screening and optimization. The model is experimentally validated using a commercially available Ni-Al multilayer foils and different alloys.

  14. Nano-alumina powders/ceramics derived from aluminum foil waste at low temperature for various industrial applications.

    PubMed

    El-Amir, Ahmed A M; Ewais, Emad M M; Abdel-Aziem, Ahmed R; Ahmed, Adel; El-Anadouli, Bahgat E H

    2016-12-01

    In this work, nanoscale single crystalline γ- and α-alumina powders have been successfully prepared from aluminum foil waste precursor via co-precipitation method using NH4OH as a precipitant. The obtained gel after co-precipitation treatment, was calcined at different temperatures (500,700, 900, 1050, 1100, 1300 and 1500 °C) and the products were characterized by XRD, FTIR and HRTEM. The results revealed that nano-γ-Al2O3 was fully transformed to nanometer-sized α-Al2O3 (36-200 nm) after annealing at temperatures as low as 1100 °C.The thermally preheated powder at 500 °C was further pressed under 95 MPa by the uniaxial press and the obtained bodies were found to have98.82% of the theoretical density, 1.18% porosity and 708 MPa compressive strength, when sintered at temperatures as low as 1600 °C without using any sintering aid. These excellent results proved that this work will contribute to finding a commercial source for preparing sub 100 nm α-alumina through the secondary resources management and even more so to synthesizing strong α-Al2O3 bodies which are promising in terms of their structure and compression. The α-Al2O3 bodies synthesized by the present work could be used as a feedstock for fabrication of various kinds of functional and structural materials that are extensively used in high tech.

  15. Analytical Scanning and Transmission Electron Microscopy of Laboratory Impacts on Stardust Aluminium Foils: Interpreting Impact Crater Morphology and the Composition of Impact Residues.

    SciTech Connect

    Kearsley, A T; Graham, G A; Burchell, M J; Cole, M J; Dai, Z R; Teslich, N; Chater, R; Wozniakiewicz, P A; Spratt, J; Jones, G

    2006-10-19

    The known encounter velocity (6.1kms{sup -1}) between the Stardust spacecraft and the dust emanating from the nucleus of comet Wild 2 has allowed realistic simulation of dust collection in laboratory experiments designed to validate analytical methods for the interpretation of dust impacts on the aluminium foil components of the Stardust collector. In this report we present information on crater gross morphology, the pre-existing major and trace element composition of the foil, geometrical issues for energy dispersive X-ray analysis of the impact residues in scanning electron microscopes, and the modification of dust chemical composition during creation of impact craters as revealed by analytical transmission electron microscopy. Together, these observations help to underpin the interpretation of size, density and composition for particles impacted upon the Stardust aluminium foils.

  16. SEM-EDS Analyses of Small Craters in Stardust Aluminum Foils: Implications for the Wild-2 Dust Distribution

    NASA Technical Reports Server (NTRS)

    Borg, J.; Horz, F.; Bridges, J. C.; Burchell, M. J.; Djouadi, Z.; Floss, C.; Graham, G. A.; Green, S. F.; Heck, P. R.; Hoppe, P.; Huth, J.; Kearsley, A; Leroux, H.; Marhas, K.; Stadermann, F. J.; Teslich, N.

    2007-01-01

    Aluminium foils were used on Stardust to stabilize the aerogel specimens in the modular collector tray. Part of these foils were fully exposed to the flux of cometary grains emanating from Wild 2. Because the exposed part of these foils had to be harvested before extraction of the aerogel, numerous foil strips some 1.7 mm wide and 13 or 33 mm long were generated during Stardusts's Preliminary Examination (PE). These strips are readily accommodated in their entirety in the sample chambers of modern SEMs, thus providing the opportunity to characterize in situ the size distribution and residue composition - employing EDS methods - of statistically more significant numbers of cometary dust particles compared to aerogel, the latter mandating extensive sample preparation. We describe here the analysis of nearly 300 impact craters and their implications for Wild 2 dust.

  17. Impact Welding of Aluminum to Copper and Stainless Steel by Vaporizing Foil Actuator: Effect of Heat Treatment Cycles on Mechanical Properties and Microstructure

    NASA Astrophysics Data System (ADS)

    Vivek, Anupam; Hansen, Steven; Benzing, Jake; He, Mei; Daehn, Glenn

    2015-10-01

    This work studies the mechanical property effect of microstructure on impact welds of aluminum alloy AA6061 with both copper alloy Cu 110 and stainless steel AISI 304. AA6061-T6 and T4 temper aluminum sheets of 1 mm thickness were launched toward copper and stainless steel targets using the vaporizing foil actuator technique. Flyer plate velocities, measured via photonic Doppler velocimetry, were observed to be approximately 800 m/s. The welded aluminum-copper samples were subjected to instrumented peel testing, microhardness testing, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The welded joints exhibited cracks through their continuous intermetallic layers. The cracks were impeded upon encountering a ductile metallic wave. The welds created with T6 temper flyer sheets were found to have smaller intermetallic-free and wavy interface regions as compared to those created with T4 temper flyer sheets. Peel strength tests of the two weld combinations resulted in failure along the interface in the case of the T6 flyer welds, while the failure generally occurred in the parent aluminum for the T4 temper flyer welds. Half of the T4 flyer welds were subjected to aging for 18 h at 433 K (160 °C) to convert the aluminum sheet to the T6 condition. Although the aged flyer material did not attain the hardness of the as-received T6 material, it was found to be significantly stronger than the T4 material. These welds retained their strength after the aging process, and diffusion across the interface was minimal. The welded aluminum-stainless steel samples were analyzed on a more basic level than aluminum-copper samples, but were found to exhibit similar results.

  18. Aluminum Foils of the Stardust Interstellar Collector: The Challenge of Recognizing Micrometer-sized Impact Craters made by Interstellar Grains

    NASA Technical Reports Server (NTRS)

    Kearsley, A. T.; Westphal, A. J.; Burchell, M. J.; Zolensky, Michael E.

    2008-01-01

    Preliminary Examination (PE) of the Stardust cometary collector revealed material embedded in aerogel and on aluminium (Al) foil. Large numbers of sub-micrometer impact craters gave size, structural and compositional information. With experience of finding and analyzing the picogram to nanogram mass remains of cometary particles, are we now ready for PE of the Interstellar (IS) collector? Possible interstellar particle (ISP) tracks in the aerogel are being identified by the stardust@home team. We are now assessing challenges facing PE of Al foils from the interstellar collector.

  19. Vacuum brazing of electroless Ni-P alloy-coated SiCp/Al composites using aluminum-based filler metal foil

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Xu, Dongxia; Niu, Jitai

    2016-12-01

    Using rapidly cooled (Al-10Si-20Cu-0.05Ce)-1Ti (wt%) foil as filler metal, the research obtained high-performance joints of electroless Ni-P alloy-coated aluminum matrix composites with high SiC particle content (60 vol%, SiCp/Al-MMCs). The effect of brazing process on joint properties and the formation of Al-Ni and Al-Cu-Ni intermetallic compounds were investigated, respectively. Due to the presence of Ni-P alloy coating, the wettability of liquid filler metal on the composites was improved obviously and its contact angle was only 21°. The formation of Al3Ni2 and Al3(CuNi)2 intermetallic compounds indicated that well metallurgical bonding occurred along the 6063Al matrix alloy/Ni-P alloy layer/filler metal foil interfaces by mutual diffusion and dissolution. And the joint shear strength increased with increasing the brazing temperature from 838 to 843 K or prolonging the soaking time from 15 to 35 min, while it decreased a lot because of corrosion occurring in the 6063Al matrix at high brazing temperature of 848 K. Sound joints with maximum shear strength of 112.5 MPa were obtained at 843 K for soaking time of 35 min. In this research, the beneficial effect of surface metallization by Ni-P alloy deposits on improving wettability on SiCp/Al-MMCs was demonstrated, and capable welding parameters were broadened as well.

  20. Foil Artists

    ERIC Educational Resources Information Center

    Szekely, George

    2010-01-01

    Foil can be shaped into almost anything--it is the all-purpose material for children's art. Foil is a unique drawing surface. It reflects, distorts and plays with light and imagery as young artists draw over it. Foil permits quick impressions of a model or object to be sketched. Foil allows artists to track their drawing moves, seeing the action…

  1. Laboratory Simulation of Impacts upon Aluminum Foils of the Stardust Spacecraft: Calibration of Dust Particle Size from Comet Wild 2

    NASA Technical Reports Server (NTRS)

    Kearsley, A. T.; Burchell, M. J.; Horz, F.; Cole, M. J.; Schwandt, C. S.

    2006-01-01

    Metallic aluminium alloy foils exposed on the forward, comet-facing surface of the aerogel tray on the Stardust spacecraft are likely to have been impacted by the same cometary particle population as the dedicated impact sensors and the aerogel collector. The ability of soft aluminium alloy to record hypervelocity impacts as bowl-shaped craters offers an opportunistic substrate for recognition of impacts by particles of a wide potential size range. In contrast to impact surveys conducted on samples from low Earth orbit, the simple encounter geometry for Stardust and Wild 2, with a known and constant spacecraft-particle relative velocity and effective surface-perpendicular impact trajectories, permits closely comparable simulation in laboratory experiments. For a detailed calibration programme we have selected a suite of spherical glass projectiles of uniform density and hardness characteristics, with well-documented particle size range from 10 microns to nearly 100 microns. Light gas gun buckshot firings of these particles at approximately 6km s)exp -1) onto samples of the same foil as employed on Stardust have yielded large numbers of craters. Scanning electron microscopy of both projectiles and impact features has allowed construction of a calibration plot, showing a linear relationship between impacting particle size and impact crater diameter. The close match between our experimental conditions and the Stardust mission encounter parameters should provide another opportunity to measure particle size distributions and fluxes close to the nucleus of Wild 2, independent of the active impact detector instruments aboard the Stardust spacecraft.

  2. In-target electron thermalization by the Weibel instability during intense irradiation of a thin aluminum foil

    NASA Astrophysics Data System (ADS)

    Fuchs, J.; Ruyer, C.; Albertazzi, B.; Lancia, L.; Dervieux, V.; Antici, P.; Bocker, J.; Chen, S. N.; Nakatsutsumi, M.; Romagnani, L.; Shepherd, R.; Swantusch, M.; Borghesi, M.; Willi, O.; Pepin, H.; Grech, M.; Riconda, C.; Gremillet, L.

    2015-11-01

    Proton-radiography of the electromagnetic fields developing after irradiation of a 3 μm-thick Al foil by a high-intensity laser (5 ×1019 W.cm-2, 700fs, 8 μm focal spot) was performed at the Titan facility. The obtained radiographs evidence filamentary structures which develop inside the dense target, 300 μ m away from the focal spot, a few picoseconds after the laser drive. We will demonstrate that the radiographs' structures are due to magnetic fields triggered by the so-called Weibel instability, inside the dense target. For this purpose, large scale particle-in-cell simulations of hot electrons thermalization in a dense, cold and collisional target have been performed. They demonstrate the ability of the laser-heated electrons to sustain a strong temperature anisotropy during their relaxation in the thin foil. This hot electron anisotropy results in a Weibel instability, thus triggering magnetic fluctuations of spectrum consistent with the experiment over 10 picoseconds.

  3. A review of computer aided interpretation technology for the evaluation of radiographs of aluminum welds

    NASA Technical Reports Server (NTRS)

    Lloyd, J. F., Sr.

    1987-01-01

    Industrial radiography is a well established, reliable means of providing nondestructive structural integrity information. The majority of industrial radiographs are interpreted by trained human eyes using transmitted light and various visual aids. Hundreds of miles of radiographic information are evaluated, documented and archived annually. In many instances, there are serious considerations in terms of interpreter fatigue, subjectivity and limited archival space. Quite often it is difficult to quickly retrieve radiographic information for further analysis or investigation. Methods of improving the quality and efficiency of the radiographic process are being explored, developed and incorporated whenever feasible. High resolution cameras, digital image processing, and mass digital data storage offer interesting possibilities for improving the industrial radiographic process. A review is presented of computer aided radiographic interpretation technology in terms of how it could be used to enhance the radiographic interpretation process in evaluating radiographs of aluminum welds.

  4. Synthesis of VACNFs on Aluminum Foil and Their Transfer to PDMS while Maintaining Alignment and Impalefection Functionality

    SciTech Connect

    Railsback, Justin; Pearce, Ryan; Sarac, Mehmet; ANDERSON, BRYAN; McKnight, Timothy E; Tracy, Joseph B; Melechko, Anatoli

    2013-01-01

    Vertically aligned carbon nanofibers (VACNFs) are synthesized on 3003 aluminum substrates by direct current plasma enhanced chemical vapor deposition. Chemically synthesized nickel nanoparticles were used as the catalyst for growth. The silicon containing coating (SiNx) typically produced when VACNFs are grown on silicon was produced by adding silicon microparticles prior to growth. The fiber array was transferred to PDMS by spin casting a layer on the grown substrates, curing the PDMS, and etching away the aluminum in KOH. Energy dispersive x-ray spectroscopy, scanning electron microscopy, and fluorescence microscopy data are provided. The free standing array in PDMS was then loaded with pVENUS-C1 plasmid and human brain microcapillary endothelial cells (HCMECHBMEC)/d3 cells were successfully impalefected with the plasmid.

  5. Aluminum and Young Artists.

    ERIC Educational Resources Information Center

    Anderson, Thomas

    1980-01-01

    The author suggests a variety of ways in which aluminum and aluminum foil can be used in elementary and junior high art classes: relief drawing and rubbing; printing; repousse; sculpture; mobiles; foil sculpture; and three dimensional design. Sources of aluminum supplies are suggested. (SJL)

  6. Prediction and characterization of heat-affected zone formation in tin-bismuth alloys due to nickel-aluminum multilayer foil reaction

    SciTech Connect

    Hooper, R. J.; Davis, C. G.; Johns, P. M.; Adams, D. P.; Hirschfeld, D.; Nino, J. C.; Manuel, M. V.

    2015-06-26

    Reactive multilayer foils have the potential to be used as local high intensity heat sources for a variety of applications. In this study, most of the past research effort concerning these materials have focused on understanding the structure-property relationships of the foils that govern the energy released during a reaction. To improve the ability of researchers to more rapidly develop technologies based on reactive multilayer foils, a deeper and more predictive understanding of the relationship between the heat released from the foil and microstructural evolution in the neighboring materials is needed. This work describes the development of a numerical model for the purpose of predicting heat affected zone size in substrate materials. The model is experimentally validated using a commercially available Ni-Al multilayer foils and alloys from the Sn-Bi binary system. To accomplish this, phenomenological models for predicting the variation of physical properties (i.e., thermal conductivity, density, and heat capacity) with temperature and composition in the Sn-Bi system were utilized using literature data.

  7. Prediction and characterization of heat-affected zone formation in tin-bismuth alloys due to nickel-aluminum multilayer foil reaction

    DOE PAGES

    Hooper, R. J.; Davis, C. G.; Johns, P. M.; ...

    2015-06-26

    Reactive multilayer foils have the potential to be used as local high intensity heat sources for a variety of applications. In this study, most of the past research effort concerning these materials have focused on understanding the structure-property relationships of the foils that govern the energy released during a reaction. To improve the ability of researchers to more rapidly develop technologies based on reactive multilayer foils, a deeper and more predictive understanding of the relationship between the heat released from the foil and microstructural evolution in the neighboring materials is needed. This work describes the development of a numerical modelmore » for the purpose of predicting heat affected zone size in substrate materials. The model is experimentally validated using a commercially available Ni-Al multilayer foils and alloys from the Sn-Bi binary system. To accomplish this, phenomenological models for predicting the variation of physical properties (i.e., thermal conductivity, density, and heat capacity) with temperature and composition in the Sn-Bi system were utilized using literature data.« less

  8. The Eroding Foil Switch (EFS) model

    NASA Astrophysics Data System (ADS)

    Brandenburg, John E.; Terry, Robert E.

    1986-01-01

    An analysis of the results of two experiments, the Los Alamos Foil Switch Experiment and the Magnetic Gate Experiment, reveals evidence of mass loss and unexpectedly high temperatures in strongly accelerated aluminum foils. Nonlinear magnetic diffusion theory is analyzed both analytically and numerically and found to give strong concentrations of current density, in a propagating front, for foils thicker than a classical skin depth. This concentrated current front is found to lead to mass erosion and high temperatures in foils undergoing strong acceleration. These results are used to formulate a new model of foil kinematics called the EFS model that features both a rocket (or mass loss) phase, and a snowplow (shock wave) phase after foil disassembly. This model is shown to give good agreement with experimental results.

  9. Foil bearings

    NASA Technical Reports Server (NTRS)

    Elrod, David A.

    1993-01-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

  10. Foil bearings

    NASA Astrophysics Data System (ADS)

    Elrod, David A.

    1993-11-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

  11. Carbon-Coated Porous Aluminum Foil Anode for High-Rate, Long-Term Cycling Stability, and High Energy Density Dual-Ion Batteries.

    PubMed

    Tong, Xuefeng; Zhang, Fan; Ji, Bifa; Sheng, Maohua; Tang, Yongbing

    2016-12-01

    A 3D porous Al foil coated with a uniform carbon layer (pAl/C) is prepared and used as the anode and current collector in a dual-ion battery (DIB). The pAl/C-graphite DIB demonstrates superior cycling stability and high rate performance, achieving a highly reversible capacity of 93 mAh g(-1) after 1000 cycles at 2 C over the voltage range of 3.0-4.95 V. In addition, the DIB could achieve an energy density of ≈204 Wh kg(-1) at a high power density of 3084 W kg(-1) .

  12. Foil Electron Multiplier

    DOEpatents

    Funsten, Herbert O.; Baldonado, Juan R.; Dors, Eric E.; Harper, Ronnie W.; Skoug, Ruth M.

    2006-03-28

    An apparatus for electron multiplication by transmission that is designed with at least one foil having a front side for receiving incident particles and a back side for transmitting secondary electrons that are produced from the incident particles transiting through the foil. The foil thickness enables the incident particles to travel through the foil and continue on to an anode or to a next foil in series with the first foil. The foil, or foils, and anode are contained within a supporting structure that is attached within an evacuated enclosure. An electrical power supply is connected to the foil, or foils, and the anode to provide an electrical field gradient effective to accelerate negatively charged incident particles and the generated secondary electrons through the foil, or foils, to the anode for collection.

  13. Foil changing apparatus

    DOEpatents

    Crist, Charles E.; Ives, Harry C.; Leifeste, Gordon T.; Miller, Robert B.

    1988-01-01

    A self-contained hermetically sealed foil changer for advancing a portion of foil web into a position normal to the path of a high energy particle beam. The path of the beam is defined generally by an aperture plate and cooperating axially movable barrel such that the barrel can be advanced toward the plate thereby positioning a portion of the foil across the beam path and sealing the foil between the barrel and the plate to form a membrane across said beam path. A spooling apparatus contained in the foil changer permits selectively advancing a fresh supply of foil across the beam path without breaking the foil changer seal.

  14. [Sunrise gold foil jacket crown].

    PubMed

    Lecardonnel, A

    1989-09-01

    This technique permits the preparation of ceramic jacket crowns made on Sunrise laminated precious metal alloy. The Sunrise foil is gold-colored, made of 99% of precious metals and is 50 microns thick. The die is prepared in order to display a moderate and regular undercut beyond the cervical limit. The margin will be underlined with a red pencil. The Sunrise foil is cut according to predetermined templates. Then the foil is applied without burnishing, according to the technique of jacket crowns on platinum foil only by finger pressure. The double folding on closure is preferably done distally or mesially. Then, the metal base is disinserted, sandblasted with 100 microns aluminum oxide, replaced on its die, and placed in a rubber casing before being placed in the isostatic press, to be subjected to a pressure of 2,000 TSI (14 kg par cm2). Sunrise's orange color reinforces rather subtetly the overall color, making these reconstructions particularly esthetic. The color of the Sunrise metal does not require, therefore a too thick opaque. Any ceramic intended to be fired on a metal base, may be used in respecting its firing protocol. Sunrise, as any other technique of this type, require a careful preparation with a shoulder that has a rounded gingivoaxial line angle. Bridges may be built on the "thimbles" crowns, fitted on Sunrise cores, the pontics being made as a ceramo-metal framework.

  15. Foil Panel Mirrors for Nonimaging Applications

    NASA Technical Reports Server (NTRS)

    Kuyper, D. J.; Castillo, A. A.

    1984-01-01

    Large durable, lightweight mirrors made by bonding thick aluminum foil to honeycomb panels or other rigid, flat backings. Mirrors suitable for use as infrared shields, telescope doors, solar-furnance doors, advertising displays, or other reflectors that require low thermal emissivity and high specularity but do not require precise surface figure necessary for imaging.

  16. Bonded Invar Clip Removal Using Foil Heaters

    NASA Technical Reports Server (NTRS)

    Pontius, James T.; Tuttle, James G.

    2009-01-01

    A new process uses local heating and temperature monitoring to soften the adhesive under Invar clips enough that they can be removed without damaging the composite underneath or other nearby bonds. Two 1x1 in. (approx.2.5x2.5 cm), 10-W/sq in. (approx.1.6-W/sq cm), 80-ohm resistive foil Kapton foil heaters, with pressure-sensitive acrylic adhesive backing, are wired in parallel to a 50-V, 1-A limited power supply. At 1 A, 40 W are applied to the heater pair. The temperature is monitored in the clip radius and inside the tube, using a dual thermocouple readout. Several layers of aluminum foil are used to speed the heat up, allowing clips to be removed in less than five minutes. The very local heating via the foil heaters allows good access for clip removal and protects all underlying and adjacent materials.

  17. 78 FR 34649 - Aluminum Extrusions From the People's Republic of China: Preliminary Results of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ... International Trade Administration Aluminum Extrusions From the People's Republic of China: Preliminary Results...) is conducting an administrative review of the countervailing duty (CVD) order on aluminum extrusions... Aluminum Co., Ltd. (Alnan Aluminum), Alnan Aluminum Foil Co., Ltd. (Alnan Foil), Alnan (Shanglin)...

  18. A MODERN INTERPRETATION OF THE BARNEY DIAGRAM FOR ALUMINUM SOLUBILITY IN TANK WASTE

    SciTech Connect

    REYNOLDS JG; REYNOLDS DA

    2009-12-16

    Experimental and modeling studies of aluminum solubility in Hanford tank waste have been developed and refined for many years in efforts to resolve new issues or develop waste treatment flowsheets. The earliest of these studies was conducted by G. Scott Barney, who performed solubility studies in highly concentrated electrolyte solutions to support evaporator campaign flowsheets in the 1970's. The 'Barney Diagram', a term still widely used at Hanford today, suggested gibbsite ({gamma}-Al(OH){sub 3}) was much more soluble in tank waste than in simple sodium hydroxide solutions. These results, which were highly surprising at the time, continue to be applied to new situations where aluminum solubility in tank waste is of interest. Here, we review the history and provide a modern explanation for the large gibbsite solubility observed by Barney, an explanation based on basic research that has been performed and published in the last 30 years. This explanation has both thermodynamic and kinetic aspects. Thermodynamically, saturated salt solutions stabilize soluble aluminate species that are minor components in simple sodium hydroxide solutions. These species are the aluminate dimer and the sodium-aluminate ion-pair. Ion-pairs must be present in the Barney simulants because calculations showed that there was insufficient space between the highly concentrated ions for a water molecule. Thus, most of the ions in the simulants have to be ion-paired. Kinetics likely played a role as well. The simulants were incubated for four to seven days, and more recent data indicate that this was unlikely sufficient time to achieve equilibrium from supersaturation. These results allow us to evaluate applications of the Barney results to current and future tank waste issues or flowsheets.

  19. Efficient laser-proton acceleration from an insulating foil with an attached small metal disk

    SciTech Connect

    Otani, Kazuto; Tokita, Shigeki; Nishoji, Toshihiko; Inoue, Shunsuke; Hashida, Masaki; Sakabe, Shuji

    2011-10-17

    Efficient proton acceleration by the interaction of an intense femtosecond laser pulse with a solid foil has been demonstrated. An aluminum coating (thickness: 0.2 {mu}m) on a polyethylene (PE) foil was irradiated at 2 x 10{sup 18} W/cm{sup 2} intensity. The protons from the aluminum-disk (diameter: 150 {mu}m to 15 mm) foil were accelerated to much higher energy in comparison with conventional targets such as PE and aluminum-coated PE foils. The fast electron signal along the foil surface was significantly higher from the aluminum-coated PE foil. The laser-proton acceleration appeared to be affected to the size of surrounding conductive material.

  20. Apparatus and process for ultrasonic seam welding stainless steel foils

    DOEpatents

    Leigh, Richard W.

    1992-01-01

    An ultrasonic seam welding apparatus having a head which is rotated to form contact, preferably rolling contact, between a metallurgically inert coated surface of the head and an outside foil of a plurality of layered foils or work materials. The head is vibrated at an ultrasonic frequency, preferably along a longitudinal axis of the head. The head is constructed to transmit vibration through a contacting surface of the head into each of the layered foils. The contacting surface of the head is preferably coated with aluminum oxide to prevent the head from becoming welded to layered stainless steel foils.

  1. Thin layer chromatography-spray mass spectrometry: a method for easy identification of synthesis products and UV filters from TLC aluminum foils.

    PubMed

    Himmelsbach, Markus; Waser, Mario; Klampfl, Christian W

    2014-06-01

    A straightforward procedure for direct mass spectrometric (MS) analysis of spots from thin layer chromatography (TLC) plates, without the need of an external ion source, was developed using the aluminum plate backing as spray tip. The spots were cut out shaped as a tip with a 60° angle, mounted in front of the MS orifice, and after addition of a spray solvent spectra were obtained immediately. A high-resolution time-of-flight MS was used since the method is of particular interest for rapid identification or confirmation of spots from TLC plates. The practical benefits of this technique were demonstrated by detection of by-products of organic reactions, by identification of degradation products, and by accurate confirmation of spots when UV filters in sunscreens were analyzed by TLC. Employing the described method TLC spots can be evaluated fast without the need of an external ion source or devices for analyte transfer from TLC to MS, only a basic MS instrument and a high-voltage power supply is required.

  2. Method of forming a thin unbacked metal foil

    DOEpatents

    Duchane, David V.; Barthell, Barry L.

    1984-01-01

    In a method of forming a thin (<2 .mu.m) unbacked metal foil having a desired curviplanar shape, a soluble polymeric film, preferably comprising polyvinyl alcohol, is formed on a supporting structure having a shape that defines the desired shape of the foil product. A layer of metal foil is deposited onto one side of the soluble film, preferably by vacuum vapor deposition. The metallized film is then immersed in a suitable solvent to dissolve the film and thereby leave the metal foil as an unbacked metal foil element mounted on the supporting structure. Aluminum foils less than 0.2 .mu.m (2,000 .ANG.) thick and having an areal density of less than 54 .mu.g/cm.sup.2 have been obtained.

  3. Carbon stripper foils used in the Los Alamos PSR

    SciTech Connect

    Borden, M.J.; Plum, M.A.; Sugai, I.

    1997-12-01

    Carbon stripper foils produced by the modified controlled ACDC arc discharge method (mCADAD) at the Institute for Nuclear Study have been tested and used for high current 800-MeV beam production in the Proton Storage Ring (PSR) since 1993. Two foils approximately 110 {mu}g/cm{sup 2} each are sandwiched together to produce an equivalent 220 {mu}g/cm{sup 2} foil. The foil sandwitch is supported by 4-5 {mu}m diameter carbon filters attached to an aluminum frame. These foils have survived as long as five months during PSR normal beam production of near 70 {mu}A average current on target. Typical life-times of other foils vary from seven to fourteen days with lower on-target average current. Beam loss data also indicate that these foils have slower shrinkage rates than standard foils. Equipment has been assembled and used to produce foils by the mCADAD method at Los Alamos. These foils will be tested during 1997 operation.

  4. Foil optimization for low energy neutral atom imaging

    SciTech Connect

    Funsten, H.O.; McComas, D.J.; Barraclough, B.L.

    1992-01-01

    Magnetospheric imaging has been proposed using remote detection of low energy neutral atoms (LENAs) of magnetospheric origin. In the detector, LENAs can be removed from the immense ambient EUV by charge modification (ionization) using a carbon stripping foil and can be subsequently deflected into an E/q analysis section. The detector sensitivity efficiency of LENAs is highly dependent on the ionization probability of neutrals as they transit the carbon foil. In this study, we present equilibrium charge state distributions and scatter distributions for 1-30 keV atomic hydrogen and oxygen transiting 0.5 {mu}g cm{sup {minus}2} carbon foils. The fraction of hydrogen exiting a foil as H{sup +} ranges from approximately 5% at 1 keV to 41% at 30 keV. The fraction of oxygen exiting the foil as O{sup +} ranges from 2% at 10 keV to 8% at 30 keV. Results obtained after coating the exit surface of foils with either aluminum (which forms aluminum oxide when exposed to air) or gold suggests that the exit surface chemistry has no effect on the charge state distributions due to foil contamination from exposure to air. Scattering resulting from the atom-foil interaction is shown to be independent of the charge state distribution, suggesting that the interaction mechanisms resulting in charge exchange and scattering are distinctly different.

  5. Interpretations

    NASA Astrophysics Data System (ADS)

    Bellac, Michel Le

    2014-11-01

    Although nobody can question the practical efficiency of quantum mechanics, there remains the serious question of its interpretation. As Valerio Scarani puts it, "We do not feel at ease with the indistinguishability principle (that is, the superposition principle) and some of its consequences." Indeed, this principle which pervades the quantum world is in stark contradiction with our everyday experience. From the very beginning of quantum mechanics, a number of physicists--but not the majority of them!--have asked the question of its "interpretation". One may simply deny that there is a problem: according to proponents of the minimalist interpretation, quantum mechanics is self-sufficient and needs no interpretation. The point of view held by a majority of physicists, that of the Copenhagen interpretation, will be examined in Section 10.1. The crux of the problem lies in the status of the state vector introduced in the preceding chapter to describe a quantum system, which is no more than a symbolic representation for the Copenhagen school of thought. Conversely, one may try to attribute some "external reality" to this state vector, that is, a correspondence between the mathematical description and the physical reality. In this latter case, it is the measurement problem which is brought to the fore. In 1932, von Neumann was first to propose a global approach, in an attempt to build a purely quantum theory of measurement examined in Section 10.2. This theory still underlies modern approaches, among them those grounded on decoherence theory, or on the macroscopic character of the measuring apparatus: see Section 10.3. Finally, there are non-standard interpretations such as Everett's many worlds theory or the hidden variables theory of de Broglie and Bohm (Section 10.4). Note, however, that this variety of interpretations has no bearing whatsoever on the practical use of quantum mechanics. There is no controversy on the way we should use quantum mechanics!

  6. Interpretation of Wild 2 Dust Fine Structure: Comparison of Stardust Aluminium Foil Craters to the Three-Dimensional Shape of Experimental Impacts by Artificial Aggregate Particles and Meteorite Powders

    SciTech Connect

    Kearsley, A T; Burchell, M J; Price, M C; Graham, G A; Wozniakiewicz, P J; Cole, M J; Foster, N J; Teslich, N

    2009-12-10

    New experimental results show that Stardust crater morphology is consistent with interpretation of many larger Wild 2 dust grains being aggregates, albeit most of low porosity and therefore relatively high density. The majority of large Stardust grains (i.e. those carrying most of the cometary dust mass) probably had density of 2.4 g cm{sup -3} (similar to soda-lime glass used in earlier calibration experiments) or greater, and porosity of 25% or less, akin to consolidated carbonaceous chondrite meteorites, and much lower than the 80% suggested for fractal dust aggregates. Although better size calibration is required for interpretation of the very smallest impacting grains, we suggest that aggregates could have dense components dominated by {micro}m-scale and smaller sub-grains. If porosity of the Wild 2 nucleus is high, with similar bulk density to other comets, much of the pore-space may be at a scale of tens of micrometers, between coarser, denser grains. Successful demonstration of aggregate projectile impacts in the laboratory now opens the possibility of experiments to further constrain the conditions for creation of bulbous (Type C) tracks in aerogel, which we have observed in recent shots. We are also using mixed mineral aggregates to document differential survival of pristine composition and crystalline structure in diverse fine-grained components of aggregate cometary dust analogues, impacted onto both foil and aerogel under Stardust encounter conditions.

  7. Cryogenic foil bearing turbopumps

    NASA Technical Reports Server (NTRS)

    Gu, Alston L.

    1993-01-01

    Cryogenic foil bearing turbopumps offer high reliability and low cost. The fundamental cryogenic foil bearing technology has been validated in both liquid hydrogen and liquid oxygen. High load capacity, excellent rotor dynamics, and negligible bearing wear after over 100 starts and stops, and over many hours of testing, were observed in both fluids. An experimental liquid hydrogen foil bearing turbopump was also successfully demonstrated. The results indicate excellent stability, high reliability, wide throttle-ability, low bearing cooling flow, and two-phase bearing operability. A liquid oxygen foil bearing turbopump has been built and is being tested at NASA MSFC.

  8. Degrader foils for the CARIBU project

    NASA Astrophysics Data System (ADS)

    Greene, John P.; Savard, Guy; Pardo, Richard C.; Baker, Samuel I.; Levand, Anthony F.; Zabransky, Bruce J.

    2011-11-01

    The Californium Rare Ion Breeder Upgrade (CARIBU) project was conceived to provide neutron rich beams originating from the 3% fission decay branch of a 252Cf source to be accelerated by the Argonne Tandem Linear Accelerator System (ATLAS). This 1Ci 252Cf source will be housed in a movable shielded cask, from which it can be directly transferred into a large helium gas stopper cell. Within the gas stopper, the CARIBU 252Cf source is positioned behind an aluminum degrader foil where the radioactive recoils of interest lose most of their energy before being stopped in the helium gas. To stop recoils over the full fission mass range effectively, three degraders of increasing thickness are required, one to cover the light fission peak and two for the isotopes in the heavy fission peak. The geometry of the source within the gas cell would ideally require a hemispherically shaped degrader foil for uniform energy loss of the fission products. The fabrication of a thin foil of such a shape proved to be exceedingly difficult and, therefore, a compromise "top hat" arrangement was designed. In addition, the ultra-high vacuum (UHV) environment necessary for the gas cell to function properly prevented the use of any epoxy due to vacuum outgassing. Handling, assembling of the foils and mounting must be done under clean room conditions. Details of early attempts at producing these foils as well as handling and mounting will be discussed.

  9. Foil Face Seal Testing

    NASA Technical Reports Server (NTRS)

    Munson, John

    2009-01-01

    In the seal literature you can find many attempts by various researchers to adapt film riding seals to the gas turbine engine. None have been successful, potential distortion of the sealing faces is the primary reason. There is a film riding device that does accommodate distortion and is in service in aircraft applications, namely the foil bearing. More specifically a foil thrust bearing. These are not intended to be seals, and they do not accommodate large axial movement between shaft & static structure. By combining the 2 a unique type of face seal has been created. It functions like a normal face seal. The foil thrust bearing replaces the normal primary sealing surface. The compliance of the foil bearing allows the foils to track distortion of the mating seal ring. The foil seal has several perceived advantages over existing hydrodynamic designs, enumerated in the chart. Materials and design methodology needed for this application already exist. Also the load capacity requirements for the foil bearing are low since it only needs to support itself and overcome friction forces at the antirotation keys.

  10. 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.

  11. Beam-foil spectroscopy

    SciTech Connect

    Berry, H.G.; Hass, M.

    1982-01-01

    A brief survey of some applications of beam-foil spectroscopy is presented. Among the topics covered are lifetime and magnetic moment measurements, nuclear alignment, and polarized light production. (AIP)

  12. Direct observation of spin-like reaction fronts in planar energetic multilayer foils.

    SciTech Connect

    Adams, David Price; Hodges, V. Carter; Jones, Eric D., Jr.; McDonald, Joel Patrick

    2008-10-01

    Propagating reactions in initially planar cobalt/aluminum exothermic multilayer foils have been investigated using high-speed digital photography. Real-time observations of reactions indicate that unsteady (spinlike) reaction propagation leads to the formation of highly periodic surface morphologies with length scales ranging from 1 {micro}m to 1 mm. The characteristics of propagating spinlike reactions and corresponding reacted foil morphologies depend on the bilayer thickness of multilayer foils.

  13. SNS Injection Foil Experience

    SciTech Connect

    Cousineau, Sarah M; Galambos, John D; Kim, Sang-Ho; Ladd, Peter; Luck, Chris; Peters, Charles C; Polsky, Yarom; Shaw, Robert W; Macek, Robert James; Raparia, Deepak; Plum, Michael A

    2010-01-01

    The Spallation Neutron Source comprises a 1 GeV, 1.4 MW linear accelerator followed by an accumulator ring and a liquid mercury target. To manage the beam loss caused by the H0 excited states created during the H charge exchange injection into the accumulator ring, the stripper foil is located inside one of the chicane dipoles. This has some interesting consequences that were not fully appreciated until the beam power reached about 840 kW. One consequence was sudden failure of the stripper foil system due to convoy electrons stripped from the incoming H beam, which circled around to strike the foil bracket and cause bracket failure. Another consequence is that convoy electrons can reflect back up from the electron catcher and strike the foil and bracket. An additional contributor to foil system failure is vacuum breakdown due to the charge developed on the foil by secondary electron emission. In this paper we will detail these and other interesting failure mechanisms, and describe the improvements we have made to mitigate them.

  14. A Novel and Generalized Lithium-Ion-Battery Configuration utilizing Al Foil as Both Anode and Current Collector for Enhanced Energy Density.

    PubMed

    Ji, Bifa; Zhang, Fan; Sheng, Maohua; Tong, Xuefeng; Tang, Yongbing

    2017-02-01

    A novel battery configuration based on an aluminum foil anode and a conventional cathode is developed. The aluminum foil plays a dual role as both the active anode material and the current collector, which enhances the energy density of the packaged battery, and reduces the production cost. This generalized battery configuration has high potential for application in next-generation lithium-ion batteries.

  15. Monolithic exploding foil initiator

    SciTech Connect

    Welle, Eric J; Vianco, Paul T; Headley, Paul S; Jarrell, Jason A; Garrity, J. Emmett; Shelton, Keegan P; Marley, Stephen K

    2012-10-23

    A monolithic exploding foil initiator (EFI) or slapper detonator and the method for making the monolithic EFI wherein the exploding bridge and the dielectric from which the flyer will be generated are integrated directly onto the header. In some embodiments, the barrel is directly integrated directly onto the header.

  16. Infrared particle detection for battery electrode foils

    NASA Astrophysics Data System (ADS)

    Just, P.; Ebert, L.; Echelmeyer, T.; Roscher, M. A.

    2013-11-01

    Failures of electrochemical cells caused by internal shorts still are an important issue to be faced by the cell manufacturers and their customers. A major cause for internal shorts are contaminated electrode foils. These contaminations have to be detected securely via a non-destructive inspection technique integrated into the electrode manufacturing process. While optical detection already is state of the art, infrared detection of particles finds a new field of application in the battery electrode manufacturing process. This work presents two approaches focusing on electrode inspection by electromagnetic radiation (visible and infrared). Copper foils with a carbon based coating were intentionally contaminated by slivers of aluminum and copper as well as by abraded coating particles. Optical excitation by a flash and a luminescent lamp was applied at different angles in order to detect the reflected visible radiation. A laser impulse was used to heat up the specimen for infrared inspection. Both approaches resulted in setups providing a high contrast between contaminations and the coated electrode foil. It is shown that infrared detection offers a higher security thanks to its reliance on absorbance and emissivity instead of reflectivity as it is used for optical detection. Infrared Detection offers a potential since it is hardly influenced by the particle's shape and orientation and the electrode's waviness.

  17. Interpretation of observations made using local electrochemical impedance mapping (LEIM) on organic coated aluminum alloy 2024-T3

    NASA Astrophysics Data System (ADS)

    Mierisch, Amber Menemsha

    2001-08-01

    Local Electrochemical Impedance Mapping (LED4) was used to investigate local underfilm corrosion of organic coated (epoxy, polyurethane, vinyl) aluminum alloy 2024- T3 substrates immersed in chloride solutions. Several interesting features in LEIM were observed that would provide insight into the local breakdown processes of coated metals if they reflected actual electrochemical phenomena. Contribution to measurements from' artifact or quantities unrelated to breakdown, and the general effect of the dielectric layer on LEIM, were evaluated by comparison of analytical and numerical modeling to LEIM of fabricated electrodes. An equipotential disk was used to model underfilm corrosion. The fields calculated for these models were correlated with LEIM of both bare and coated fabricated electrodes (Au, Pt, Al, Cu). Numerical modeling predicted that a dielectric layer would dull edge effects and severely dampen the magnitude of the field emanating from the substrate surface. A salt film beneath the coating was predicted to have no significant effect on the field. LEIM of coated disk electrodes showed no evidence of the underfilm electrode with two exceptions: (1)underfilm corrosion occurring on pure aluminum, and (2)a copper electrode, which has a very active surface. The discrepancy between modeling and experimental results of coated systems prompted further experimental investigation to isolate the roles of current density and coating defects. Blisters were created on coated gold samples by placing NaCl and AlCl3 salt islands beneath the coating for various coating and substrate configurations. LEIM recorded a peak in admittance only over an acidic blister in polyurethane where local hydrolysis had occurred. It was determined that one of two criteria is required to measure electrochemical activity through a film: (1)the substrate must be actively corroding to produce a current density sufficient to generate a measurable field, or (2)a low resistivity defect must exist

  18. Summary of recent experiments on focusing of target-normal-sheath-accelerated proton beam with a stack of conducting foils

    SciTech Connect

    Ni, P. A.; Alexander, N.; Barnard, J. J.; Lund, S. M.

    2014-05-15

    We present a summary of recent experiments on focusing of laser target-normal-sheath-accelerated (TNSA) proton beam with a stack of thin conducting foils. The experiments were performed using the Phelix laser (GSI-Darmstadt) and the Titan laser, Lawrence Livermore National Laboratory. The phenomena consistent with self-collimation (or weak self-focusing) of TNSA protons were experimentally observed for the first time at the Phelix laser user facility, in a specially engineered structure ('lens') consisting of a stack of 300 thin aluminum foils separated by 50 μm vacuum gaps. Follow up experiments using the Titan laser obtained results consistent with the collimation/focusing observed in the initial experiments using the Phelix. The Titan experiments employed improved, 25 μm- and 50 μm-gap targets and the new fine mesh diagnostic. All the experiments were carried out in a “passive environment,” i.e., no external fields were applied, and no neutralization plasma or injection of secondary charged particles was imposed. A plausible interpretation of the observed phenomena is that the combination of magnetic self-pinch forces generated by the beam current together with the simultaneous reduction of the repulsive electrostatic forces due to the conducting foils inhibits radial expansion of the beam.

  19. Compliant Foil Seal Investigations

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret; Delgado, Irebert

    2004-01-01

    Room temperature testing of an 8.5 inch diameter foil seal was conducted in the High Speed, High Temperature Turbine Seal Test Rig at the NASA Glenn Research Center. The seal was operated at speeds up to 30,000 rpm and pressure differentials up to 75 psid. Seal leakage and power loss data will be presented and compared to brush seal performance. The failure of the seal and rotor coating at 30,000 rpm and 15 psid will be presented and future development needs discussed.

  20. Oxidation resistance of aluminum-coated Fe-20Cr alloys containing rare earths or yttrium

    SciTech Connect

    Sigler, D.R. )

    1993-10-01

    Aluminum-coated Fe-20Cr (rare earth or yttrium) alloy foils were developed with oxidation resistance equivalent or superior to Fe-20Cr-5Al (rare earth or yttrium) alloy foils. The coated foils were made by dipping Fe-20Cr sheet into a salt-covered aluminum bath and then rolling the sheet to foil. Oxidation resistance of the coated foil was enhanced by adding rare earths or yttrium to the Fe-20Cr substrate alloys to insure oxide adherence. Test results indicate that only sufficient addition to tie up sulfur as a stable sulfide is needed in the Fe-20Cr alloy. Aluminum-coated foils show lower oxide growth rates than similar Fe-Cr-Al alloys, most likely the result of fewer impurities (particularly Fe) is the coated foils' growing oxide scale. 31 refs., 18 figs., 2 tabs.

  1. Instabilities in foil implosions and the effect of radiation output

    SciTech Connect

    Oona, H.; Peterson, D.L.; Goforth, J.H.

    1995-08-01

    One of the aims of the Athena program at the Los Alamos National Laboratory is the generation of a high fluence of soft x-rays from the thermalization of an radially imploding foil. In the experiments in Athena program, a large axial current is passed through a cylindrical aluminum foil. Under the action of the Lorentz force, the resulting plasma accelerates toward the axis, thermalizes, and produces a fast soft x-ray pulse with a blackbody temperature up to several hundred electron volts. In order that there be the maximum power compression and the highest x-ray fluence and temperature, the plasma stagnation on axis must occur very promptly. This requires that the imploding plasma be as thin and symmetric as possible. A serious problem in the thermalization process is the formation of instabilities in the plasma due to the self-magnetic field that governs the implosion of foil. A large diagnostic effort was developed to capture the details of the implosion and instability growth in several foil implosion experiments. In this report, we will present visible light images and x-ray data designed to study the effects of foil mass, current, and initial perturbations on the instability growth during foil implosion. Representative data is presented from several experiments using the Pegasus capacitor bank system and the explosively driven Procyon system. These experiments are labeled Peg 25 and Peg 33 for the Pegasus experiments and PDD1, PDD2 and PRF0 for the Procyon experiments. In these experiments, all foils had radii of 5 centimeters but varied in mass and initial conditions. Experimental data from several shots were compared with each other and to a radiation magnetohydrodynamic (RMHD) computation and described in a separate paper.

  2. FOIL ELEMENT FOR NUCLEAR REACTOR

    DOEpatents

    Noland, R.A.; Walker, D.E.; Spinrad, B.I.

    1963-07-16

    A method of making a foil-type fuel element is described. A foil of fuel metal is perforated in; regular design and sheets of cladding metal are placed on both sides. The cladding metal sheets are then spot-welded to each other through the perforations, and the edges sealed. (AEC)

  3. Consequences of FOIL for Undergraduates

    ERIC Educational Resources Information Center

    Koban, Lori; Sisneros-Thiry, Simone

    2015-01-01

    FOIL is a well-known mnemonic that is used to find the product of two binomials. We conduct a large sample (n = 252) observational study of first-year college students and show that while the FOIL procedure leads to the accurate expansion of the product of two binomials for most students who apply it, only half of these students exhibit conceptual…

  4. Rhenium-Foil Witness Cylinders

    NASA Technical Reports Server (NTRS)

    Knight, B. L.

    1992-01-01

    Cylindrical portion of wall of combustion chamber replaced with rhenium foil mounted on holder. Rhenium oxidizes without melting, indicating regions of excess oxidizer in combustion-chamber flow. Rhenium witness foils also useful in detecting excess oxygen and other oxidizers at temperatures between 2,000 and 3,600 degrees F in burner cores of advanced gas-turbine engines.

  5. FULL SIZE U-10MO MONOLITHIC FUEL FOIL AND FUEL PLATE FABRICATION-TECHNOLOGY DEVELOPMENT

    SciTech Connect

    G. A. Moore; J-F Jue; B. H. Rabin; M. J. Nilles

    2010-03-01

    Full-size U10Mo foils are being developed for use in high density LEU monolithic fuel plates. The application of a zirconium barrier layer too the foil is applied using a hot co-rolling process. Aluminum clad fuel plates are fabricated using Hot Isostatic Pressing (HIP) or a Friction Bonding (FB) process. An overview is provided of ongoing technology development activities, including: the co-rolling process, foil shearing/slitting and polishing, cladding bonding processes, plate forming, plate-assembly swaging, and fuel plate characterization. Characterization techniques being employed include, Ultrasonic Testing (UT), radiography, and microscopy.

  6. Boron foils for RDDS experiment

    NASA Astrophysics Data System (ADS)

    Lipski, A. R.; Rainovski, G.; Pietralla, N.; Dewald, A.

    2008-06-01

    Application of the deposition method based on the vibrational motion of micro particles in an electrostatic field [I. Sugai, Nucl. Instr. and Meth. A 397 (1997) 81] is described for the production of isotopic 11B foils. The method proved suitable for target production of this typically brittle material when a very flat target surface was required. The goal to produce 11B targets of 160-350 μg/cm 2 was achieved by depositing the boron on a thin foil substrate, such as Nb and Sn. The coated foil was stretched flat before it was mounted on a frame.

  7. Drag on swimming flexible foils

    NASA Astrophysics Data System (ADS)

    Raspa, Veronica; Ramananarivo, Sophie; Thiria, Benjamin; Godoy-Diana, Ramiro

    2013-11-01

    We study experimentally the swimming dynamics of thin flexible foils in a self-propelled configuration. Measurements of swimming speed and propulsive force are performed, together with full recordings of the elastic wave kinematics and particle image velocimetry around the swimming foils. We discuss the general problem of drag in undulatory swimming using a bluff-body type model. Our results suggest that a major contribution to the total drag is due to the trailing longitudinal vortices that roll-up on the lateral edges of the foil. Additionally, changing the aspect ratio of the foils allows us to discuss quantitatively the role of the added mass term in Lighthill's elongated-body theory for thrust production in undulatory swimming. We acknowledge support by EADS Foundation through project ``Fluids and elasticity in biomimetic propulsion.''

  8. Proactive interference and cuing effects in short-term cued recall: does foil context matter?

    PubMed

    Goh, Winston D; Tan, Huiqin

    2006-07-01

    Tehan and Humphreys's (1995, 1996) short-term cued recall paradigm showed that recall in short-term memory is cue driven. In critical trials, the participants studied two blocks of four words each and were required to forget the first block while remembering the second block. A foil in the first block (e.g., orange) was related to a target (e.g., carrot) in the second block. Proactive interference (PI) was evident when a retrieval cue was used that subsumed the foil and the target (e.g., type of juice), but not when a cue was used that subsumed only the target (e.g., type of vegetable). Four experiments were performed to examine the extent to which contextual organization in the foil block would enhance or diminish the foil's efficacy in creating PI. A novel condition was included in which the words in the foil block were studied in a phonologically related context but the target was cued semantically, and vice versa with a semantic context and phonological cue. There were no differences in recall accuracy between conditions with and without contextual organization, but reliable increases in foil intrusions were observed when contextual organization was present. Contextual organization enhanced the foil, rather than diminished it, but the strengthened foil generated PI only when the cue subsumed the foil and the target and had no effect when the cue subsumed only the target. The results are consistent with a cue-driven retrieval interpretation of short-term recall.

  9. Direct drive foil implosion experiments on Pegasus II

    SciTech Connect

    Cochrane, J.C.; Bartsch, R.R.; Benage, J.F.; Forman, P.R.; Gribble, R.F.; Hockaday, M.Y.P.; Hockaday, R.G.; Ladish, J.S.; Oona, H.; Parker, J.V.; Shlachter, J.S.; Wysocki, F.J.

    1993-05-01

    Pegasus II is the upgraded version of Pegasus, a pulsed power machine used in the Los Alamos Above Ground Experiments (AGEX) program. The goal of the program is to produce an intense (>100 TW) source of soft x-rays from the thermalization of the KE of a 1 to 10 MJ collapsing plasma source. The radiation pulse should have a maximum duration of several tens of nanoseconds and will be used in the study of fusion conditions and material properties. This paper addresses z-pinch experiments done on a capacitor bank where the radiating plasma source is formed by an imploding annular aluminum foil driven by the J {times} B forces generated by the current flowing through the foil.

  10. Method for fabricating uranium foils and uranium alloy foils

    DOEpatents

    Hofman, Gerard L.; Meyer, Mitchell K.; Knighton, Gaven C.; Clark, Curtis R.

    2006-09-05

    A method of producing thin foils of uranium or an alloy. The uranium or alloy is cast as a plate or sheet having a thickness less than about 5 mm and thereafter cold rolled in one or more passes at substantially ambient temperatures until the uranium or alloy thereof is in the shape of a foil having a thickness less than about 1.0 mm. The uranium alloy includes one or more of Zr, Nb, Mo, Cr, Fe, Si, Ni, Cu or Al.

  11. Radiative heating of thin Al foils by intense extreme ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    Grabovski, E. V.; Sasorov, P. V.; Shevelko, A. P.; Aleksandrov, V. V.; Andreev, S. N.; Basko, M. M.; Branitski, A. V.; Gritsuk, A. N.; Volkov, G. S.; Laukhin, Ya. N.; Mitrofanov, K. N.; Novikov, V. G.; Oleinik, G. M.; Samokhin, A. A.; Smirnov, V. P.; Tolstikhina, I. Yu.; Frolov, I. N.; Yakushev, O. F.

    2016-03-01

    The effect of induced transparency of thin Al foils radiatively heated by intense extreme ultraviolet (EVU) radiation has been observed. The radiation of the plasma of Z-pinches appearing under the compression of tungsten liners at the Angara-5-1 facility has been used as the radiation that heats the Al foil (peak illumination on the foil ~0.55 TW/cm2) and is transmitted through it. The photoabsorption has been studied in the formed aluminum plasma at temperatures of ~10-30 eV in the density range of ~1-20 mg/cm3 in the wavelength range of ~5-24 nm. Absorption lines of Al4+...7+ ions have been identified in the experimental spectrum. In addition, radiative gas-dynamic simulations of the foil heating and expansion have been performed taking into account radiation transfer processes.

  12. Flexible pulse-wave sensors from oriented aluminum nitride nanocolumns

    NASA Astrophysics Data System (ADS)

    Akiyama, Morito; Ueno, Naohiro; Nonaka, Kazuhiro; Tateyama, Hiroshi

    2003-03-01

    Flexible pulse-wave sensors were fabricated from density-packed oriented aluminum nitride nanocolumns prepared on aluminum foils. The nanocolumns were prepared by the rf magnetron sputtering method and were perpendicularly oriented to the aluminum foil surfaces. The sensor structure is laminated, and the structure contributes to avoiding unexpected leakage of an electric charge. The resulting sensor thickness is 50 μm. The sensor is flexible like aluminum foil and can respond to frequencies from 0.1 to over 100 Hz. The sensitivity of the sensor to pressure is proportional to the surface area. The sensor sensitively causes reversible charge signals that correlate with the pulse wave form, which contains significant information on arteriosclerosis and cardiopathy of a man sitting on it.

  13. Low absorptance porcelain-on-aluminum coating

    NASA Technical Reports Server (NTRS)

    Leggett, H.

    1979-01-01

    Porcelain thermal-control coating for aluminum sheet and foil has solar absorptance of 0.22. Specially formulated coating absorptance is highly stable, changing only 0.03 after 1,000 hours of exposure to simulated sunlight and can be applied by standard commercial methods.

  14. Reactive multilayer synthesis of hard ceramic foils and films

    DOEpatents

    Makowiecki, D.M.; Holt, J.B.

    1996-02-13

    A method is disclosed for synthesizing hard ceramic materials such as carbides, borides and aluminides, particularly in the form of coatings provided on another material so as to improve the wear and abrasion performance of machine tools, for example. The method involves the sputter deposition of alternating layers of reactive metals with layers of carbon, boron, or aluminum and the subsequent reaction of the multilayered structure to produce a dense crystalline ceramic. The material can be coated on a substrate or formed as a foil which can be coiled as a tape for later use.

  15. Reactive multilayer synthesis of hard ceramic foils and films

    DOEpatents

    Makowiecki, Daniel M.; Holt, Joseph B.

    1996-01-01

    A method for synthesizing hard ceramic materials such as carbides, borides nd aluminides, particularly in the form of coatings provided on another material so as to improve the wear and abrasion performance of machine tools, for example. The method involves the sputter deposition of alternating layers of reactive metals with layers of carbon, boron, or aluminum and the subsequent reaction of the multilayered structure to produce a dense crystalline ceramic. The material can be coated on a substrate or formed as a foil which can be coild as a tape for later use.

  16. Carbon foils for space plasma instrumentation

    NASA Astrophysics Data System (ADS)

    Allegrini, F.; Ebert, R. W.; Funsten, H. O.

    2016-05-01

    Carbon foils have been successfully used for several decades in space plasma instruments to detect ions and neutral atoms. These instruments take advantage of two properties of the particle-foil interaction: charge conversion of neutral atoms and/or secondary electron emission. This interaction also creates several adverse effects for the projectile exiting the foil, such as angular scattering and energy straggling, which usually act to reduce the sensitivity and overall performance of an instrument. The magnitude of these effects mainly varies with the incident angle, energy, and mass of the incoming projectile and the foil thickness. In this paper, we describe these effects and the properties of the interaction. We also summarize results from recent studies with graphene foils, which can be made thinner than carbon foils due to their superior strength. Graphene foils may soon replace carbon foils in space plasma instruments and open new opportunities for space research in the future.

  17. Force Generation by Flapping Foils

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, P. R.; Donnelly, M.

    1996-11-01

    Aquatic animals like fish use flapping caudal fins to produce axial and cross-stream forces. During WW2, German scientists had built and tested an underwater vehicle powered by similar flapping foils. We have examined the forces produced by a pair of flapping foils. We have examined the forced produced by a pair of flapping foils attached to the tail end of a small axisymmetric cylinder. The foils operate in-phase (called waving), or in anti-phase (called clapping). In a low-speed water tunnel, we have undertaken time-dependent measurements of axial and cross-stream forces and moments that are exerted by the vortex shedding process over the entire body. Phase-matched LDV measurements of vorticity-velocity vectors, as well as limited flow visualization of the periodic vortex shedding process have also been carried out. The direction of the induced velocity within a pair of shed vortices determines the nature of the forces produced, viz., thrust or drag or cross-stream forces. The clapping mode produces a widely dispersed symmetric array of vortices which results in axial forces only (thrust and rag). On the other hand, the vortex array is staggered in the waving mode and cross-stream (maneuvering) forces are then generated.

  18. Foil Patches Seal Small Vacuum Leaks

    NASA Technical Reports Server (NTRS)

    Spiegel, Kirk W.; Reed, David W.

    1995-01-01

    Report discloses technique to patch holes in nickel-alloy rocket-engine nozzle parts prior to vacuum brazing. Technique involves lightly spot-welding nickel foil 0.002 in. thick over hole patched, then spot-welding corrosion-resistant steel foil of same thickness over nickel foil. Once patches subject to pressure and temperature of vacuum brazing, nickel foil diffuses to bond with nickel-alloy nozzle, making vacuum-tight seal.

  19. Passive Thermal Management of Foil Bearings

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert J. (Inventor)

    2015-01-01

    Systems and methods for passive thermal management of foil bearing systems are disclosed herein. The flow of the hydrodynamic film across the surface of bearing compliant foils may be disrupted to provide passive cooling and to improve the performance and reliability of the foil bearing system.

  20. Extended foil capacitor with radially spoked electrodes

    DOEpatents

    Foster, James C.

    1990-01-01

    An extended foil capacitor has a conductive disk electrically connected in oncrushing contact to the extended foil. A conductive paste is placed through spaces between radial spokes on the disk to electrically and mechanically connect the extended foil to the disk.

  1. Experimental Investigation of the Electrothermal Instability on Planar Foil Ablation Experiments

    NASA Astrophysics Data System (ADS)

    Steiner, Adam; Patel, Sonal; Yager-Elorriaga, David; Jordan, Nicholas; Gilgenbach, Ronald; Lau, Y. Y.

    2014-10-01

    The electrothermal instability (ETI) is an important early-time physical effect on pulsed power foil ablation experiments due to its ability to seed the destructive magneto-Rayleigh-Taylor (MRT) instability. ETI occurs whenever electrical resistivity has temperature dependence; when resistivity increases with temperature, as with solid metal liners or foils, ETI forms striation structures perpendicular to current flow. These striations provide an initial perturbation for the MRT instability, which is the dominant late-time instability in planar foil ablations. The MAIZE linear transformer driver was used to drive current pulses of approximately 600 kA into 400 nm-thick aluminum foils in order to study ETI in planar geometry. Shadowgraph images of the aluminum plasmas were taken for multiple shots at various times within approximately 50 ns of current start. Fourier analysis extracted the approximate wavelengths of the instability structures on the plasma-vacuum interface. Surface metrology of pre-shot foils was performed to provide a comparison between surface roughness features and resulting plasma structure. This work was supported by US DoE. S.G. Patel and A.M. Steiner supported by NPSC funded by Sandia. D.A. Yager supported by NSF fellowship Grant # DGE 1256260.

  2. How Thin Is Foil? Applying Density to Find the Thickness of Aluminum Foil

    ERIC Educational Resources Information Center

    Concannon, James P.

    2011-01-01

    In this activity, I show how high school students apply their knowledge of density to solve an unknown variable, such as thickness. Students leave this activity with a better understanding of density, the knowledge that density is a characteristic property of a given substance, and the ways density can be measured. (Contains 4 figures and 1 table.)

  3. Sputtering of sub-micrometer aluminum layers as compact, high-performance, light-weight current collector for supercapacitors

    NASA Astrophysics Data System (ADS)

    Busom, J.; Schreiber, A.; Tolosa, A.; Jäckel, N.; Grobelsek, I.; Peter, N. J.; Presser, V.

    2016-10-01

    Supercapacitors are devices for rapid and efficient electrochemical energy storage and commonly employ carbon coated aluminum foil as the current collector. However, the thickness of the metallic foil and the corresponding added mass lower the specific and volumetric performance on a device level. A promising approach to drastically reduce the mass and volume of the current collector is to directly sputter aluminum on the freestanding electrode instead of adding a metal foil. Our work explores the limitations and performance perspectives of direct sputter coating of aluminum onto carbon film electrodes. The tight and interdigitated interface between the metallic film and the carbon electrode enables high power handling, exceeding the performance and stability of a state-of-the-art carbon coated aluminum foil current collector. In particular, we find an enhancement of 300% in specific power and 186% in specific energy when comparing aluminum sputter coated electrodes with conventional electrodes with Al current collectors.

  4. Zika Vaccine Development: Flavivirus Foils

    DTIC Science & Technology

    2016-09-01

    Martins, Bavari, Zika Vaccine Development 1 Zika Vaccine Development: Flavivirus Foils Martins KAO, Bavari S. The current Zika virus...contrast, work had been underway for decades on the development of an Ebola virus vaccine , laying the groundwork for a rapid response in 2014. The...broader community’s extensive experience with Dengue virus vaccine development and with the pros and cons of different vaccine platforms has led to

  5. Foil X-ray Mirrors

    NASA Astrophysics Data System (ADS)

    Serlemitsos, Peter J.; Soong, Yang

    1996-09-01

    Nested thin foil reflectors have made possible light weight, inexpensive and fast grazing incidence X-ray mirrors for astronomical spectroscopy over a broad band. These mirrors were developed at Goddard for the US Shuttle program and were flown on NASA's shuttleborne Astro-l mission in December 1990. Presently, the Japan/US collaborative spectroscopic mission ASCA, nearing its third year of successful operation in earth orbit, carries, four such mirrors, weighing less than 40 kg and giving total effective areas of ˜ 1200 and 420 cm2 at l and 8 keV respectively. The ˜ 420 kg observatory is the best possible example of how conical foil mirrors opened areas of research that could not have been otherwise addressed with available resources. In this paper, we will briefly review the development and performance of our first generation foil mirrors. We will also describe progress toward improving their imaging capability to prime them for use in future instruments. Such a goal is highly desirable, if not necessary for this mirror technology to remain competitive for future applications.

  6. Shock compression response of highly reactive Ni + Al multilayered thin foils

    NASA Astrophysics Data System (ADS)

    Kelly, Sean C.; Thadhani, Naresh N.

    2016-03-01

    The shock-compression response of Ni + Al multilayered thin foils is investigated using laser-accelerated thin-foil plate-impact experiments over the pressure range of 2 to 11 GPa. The foils contain alternating Ni and Al layers (parallel but not flat) of nominally 50 nm bilayer spacing. The goal is to determine the equation of state and shock-induced reactivity of these highly reactive fully dense thin-foil materials. The laser-accelerated thin-foil impact set-up involved combined use of photon-doppler-velocimetry to monitor the acceleration and impact velocity of an aluminum flyer, and VISAR interferometry was used to monitor the back free-surface velocity of the impacted Ni + Al multilayered target. The shock-compression response of the Ni + Al target foils was determined using experimentally measured parameters and impedance matching approach, with error bars identified considering systematic and experimental errors. Meso-scale CTH shock simulations were performed using real imported microstructures of the cross-sections of the multilayered Ni + Al foils to compute the Hugoniot response (assuming no reaction) for correlation with their experimentally determined equation of state. It was observed that at particle velocities below ˜150 m/s, the experimentally determined equation of state trend matches the CTH-predicted inert response and is consistent with the observed unreacted state of the recovered Ni + Al target foils from this velocity regime. At higher particle velocities, the experimentally determined equation of state deviates from the CTH-predicted inert response. A complete and self-sustained reaction is also seen in targets recovered from experiments performed at these higher particle velocities. The deviation in the measured equation of state, to higher shock speeds and expanded volumes, combined with the observation of complete reaction in the recovered multilayered foils, confirmed via microstructure characterization, is indicative of the occurrence

  7. Aluminum Hydroxide

    MedlinePlus

    Aluminum hydroxide is used for the relief of heartburn, sour stomach, and peptic ulcer pain and to ... Aluminum hydroxide comes as a capsule, a tablet, and an oral liquid and suspension. The dose and ...

  8. Revisiting the Corrosion of the Aluminum Current Collector in Lithium-Ion Batteries.

    PubMed

    Ma, Tianyuan; Xu, Gui-Liang; Li, Yan; Wang, Li; He, Xiangming; Zheng, Jianming; Liu, Jun; Engelhard, Mark H; Zapol, Peter; Curtiss, Larry A; Jorne, Jacob; Amine, Khalil; Chen, Zonghai

    2017-03-02

    The corrosion of aluminum current collectors and the oxidation of solvents at a relatively high potential have been widely investigated with an aim to stabilize the electrochemical performance of lithium-ion batteries using such components. The corrosion behavior of aluminum current collectors was revisited using a home-build high-precision electrochemical measurement system, and the impact of electrolyte components and the surface protection layer on aluminum foil was systematically studied. The electrochemical results showed that the corrosion of aluminum foil was triggered by the electrochemical oxidation of solvent molecules, like ethylene carbonate, at a relative high potential. The organic radical cations generated from the electrochemical oxidation are energetically unstable and readily undergo a deprotonation reaction that generates protons and promotes the dissolution of Al(3+) from the aluminum foil. This new reaction mechanism can also shed light on the dissolution of transitional metal at high potentials.

  9. Foil support structure for large electron guns

    SciTech Connect

    Brucker, J.P.; Rose, E.A.

    1993-08-01

    This paper describes a novel support structure for a vacuum diode used to pump a gaseous laser with an electron beam. Conventional support structures are designed to hold a foil flat and rigid. This new structure takes advantage of the significantly greater strength of metals in pure tension, utilizing curved shapes for both foil and support structure. The shape of the foil is comparable to the skin of a balloon, and the shape of the support structures is comparable to the cables of a suspension bridge. This design allows a significant reduction in foil thickness and support structure mass, resulting in a lower electron-beam loss between diode and laser gas. In addition, the foil is pre-formed in the support structure at pressures higher than operating pressure. Therefore, the foil is operated far from the yield point. Increased reliability is anticipated.

  10. Foil bearing research at Penn State

    NASA Technical Reports Server (NTRS)

    Carpino, Marc

    1993-01-01

    Foil journal bearings consist of a compliant metal shell or foil which supports a rigid journal by means of a fluid film. Foil bearings are considered to be a potential alternative to rolling element or traditional rigid surface bearings in cryogenic turbomachinery applications. The prediction of foil bearing performance requires the coupled solution of the foil deflection and the fluid flow in the bearing clearance between the rotor and the foil. The investigations being conducted in the Department of Mechanical Engineering at Penn State are focused in three areas: theoretical prediction of steady state bearing performance, modeling of the dynamic bearing characteristics to determine performance in rotor systems, and experimental verification of analysis codes. The current status and results from these efforts will be discussed.

  11. Efficiency and lifetime of carbon foils

    SciTech Connect

    Chou, W.; Kostin, M.; Tang, Z.; /Fermilab

    2006-11-01

    Charge-exchange injection by means of carbon foils is a widely used method in accelerators. This paper discusses two critical issues concerning the use of carbon foils: efficiency and lifetime. An energy scaling of stripping efficiency was suggested and compared with measurements. Several factors that determine the foil lifetime--energy deposition, heating, stress and buckling--were studied by using the simulation codes MARS and ANSYS.

  12. CHARACTERIZATION OF MONOLITHIC FUEL FOIL PROPERTIES AND BOND STRENGTH

    SciTech Connect

    D E Burkes; D D Keiser; D M Wachs; J S Larson; M D Chapple

    2007-03-01

    Understanding fuel foil mechanical properties, and fuel / cladding bond quality and strength in monolithic plates is an important area of investigation and quantification. Specifically, what constitutes an acceptable monolithic fuel – cladding bond, how are the properties of the bond measured and determined, and what is the impact of fabrication process or change in parameters on the level of bonding? Currently, non-bond areas are quantified employing ultrasonic determinations that are challenging to interpret and understand in terms of irradiation impact. Thus, determining mechanical properties of the fuel foil and what constitutes fuel / cladding non-bonds is essential to successful qualification of monolithic fuel plates. Capabilities and tests related to determination of these properties have been implemented at the INL and are discussed, along with preliminary results.

  13. Gas Foil Bearing Development Program.

    DTIC Science & Technology

    1981-09-01

    curve For the 12 -Foil Bearing. 58 8 1 0 MEASURED DATA - ~- w 3 0 CALCULATED DATA S2 0 0 10 20 30 40 50 60 70 s0 90 100 LOAD, LB Figure 29. Comparison...Government drawings, specifications, or other data are used for any purpose other than in connection with a definitely related Government procurement...formulated, furnished, or in any way supplied the said drawings, specifications, or other data , is not to be regarded by implication or otherwise as in any

  14. Technical Development Path for Gas Foil Bearings

    NASA Technical Reports Server (NTRS)

    Dellacorte, Christopher

    2016-01-01

    Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

  15. Free Surface and Flapping Foil Interactions

    NASA Astrophysics Data System (ADS)

    Ananthakrishnan, Palaniswamy

    2014-11-01

    Flapping foils for station-keeping of a near-surface body in a current is analyzed using a finite-difference method based on boundary-fitted coordinates. The foils are hinge-connected to the aft of the body and subject to pitch oscillation. Results are obtained for a range of Strouhal number, Froude number, unsteady frequency parameter τ, Reynolds number and the depth of foil submergence. Results show that at low Strouhal number (St < 0 . 1) and sub-critical unsteady parameter τ < 0 . 25 , the flapping generates drag instead of thrust. At high Strouhal number and super-critical value of the unsteady parameter (τ > 0 . 25) flapping generates high thrust with low efficiency. Thrust and efficiency are found to decrease with decreasing submergence depth of the foil. At the critical τ = 0 . 25 and shallow submergence of the foil, the standing wave generated above the foil continues to grow until breaking; both the thrust and efficiency of the foil are reduced at the critical τ. The necessary conditions for optimal thrust generation by a flapping foil underneath the free surface are found to be (i) Strouhal number in the range from 0.25 to 0.35, (ii) unsteady parameter τ > 0 . 25 and (iii) the maximum angle of attack less than 15° for the flat-plate foil. Supported by the US Office of Naval Research through the Naval Engineering Education Center (NEEC) Consortium of the University of Michigan, Ann Arbor.

  16. Technical Development Path for Foil Gas Bearings

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher

    2008-01-01

    Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

  17. Low-aluminum content iron-aluminum alloys

    SciTech Connect

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J.

    1995-06-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10 and iron = 83.71. The ignots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot-worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  18. Barrier Foil Heating Simulations Using LASNEX

    SciTech Connect

    Ho, D D

    2002-03-12

    It is necessary to place a barrier foil in front of the X-ray converter target to prevent the backstreaming ions. This research note presents the simulations of foil heating using the latest EOS tables. LASNEX simulations are carried out using both DARHT-II and ETA-II beam parameters. Results for all the foils studied here, using the DARHT-II beam parameters, show that the integrated line density along the axis at the end of the 4th pulse remains essentially unchanged even if the foils are heated by beams with relatively small beam spot sizes. The temperature can reach up to 3000 C on graphite foil but can only reach several hundred degree Celsius on Mylar foil. Simulations also show that ETA-II beam can create a ''burn-through'' hole on all the foils except graphite and diamond foils, which may require pre-heat. The threshold beam spot size required for hole formation will be compared with LASNEX simulation for the purpose of code verification.

  19. [Guided bone regeneration beneath titanium foils].

    PubMed

    Otto, Katharina; Schopper, Christian; Ewers, Rolf; Lambrecht, J Thomas

    2004-01-01

    The aim of this study was to examine the clinical and histological bony healing process beneath titanium foils used for guided tissue regeneration as well as of the Frios Algipore graft which was applied with autologous bone. 66 sinus floor elevations were carried out and examined over a period of three years and eight months. A success rate of 64% was recorded with foil incorporation. Complications occurred in form of primary and secondary disturbances in the healing process caused by exposure of the foil. 12 of the 66 foils had to be removed early. In all but one case, the augmented bone material was macroscopically well integrated despite the loss of the foil. Primary stability of the inserted dental implants into the ossified augmented site after operations of the sinus maxillaris was reached in all cases with absence of post-operative complications, and in 94% when there was postoperative exposure of the membrane. Histologically, a thin layer of connective tissue poor in cells but rich in collagen fibers appeared underneath the titanium foil. This was followed by newly-formed bony tissue transforming into osseous lamella parallel to the membrane underneath the new periost. In 65 out of 66 cases a sufficient amount of stable bone was built up locally suggesting good bio-compatibility and barrier function. Further, the foil also provided mechanical rest and supporting function for the space underneath. However, the occurrence of healing complications in 36% of the cases showed a need to improve on the titanium foils.

  20. Initial experimental evidence of self-collimation of TNSA proton beam in a stack of conducting foils

    NASA Astrophysics Data System (ADS)

    Ni, Pavel

    2013-10-01

    Phenomena consistent with self-collimation (or weak self-focusing) of laser target-normal-sheath-accelerated (TNSA) protons was experimentally observed for the first time, in a specially engineered structure (``lens'') consisting of a stack of 300 thin aluminum foils separated by 50 μm vacuum gaps. The experiments were carried out in a ``passive environment,'' i.e. no external fields applied, neutralization plasma or injection of secondary charged particles was imposed. Experiments were performed at the petawatt ``PHELIX'' laser user facility (E = 100 J, Δt = 400 fs, λ = 1062 nm) at the ``Helmholtzzentrum für Schwerionenforschung-GSI'' in Darmstadt, Germany. The observed rms beam spot reduction depends inversely on energy, with a focusing degree decreasing monotonically from 2 at 5.4 MeV to 1.5 MeV at 18.7 MeV. The physics inside the lens is complex, resulting in a number of different mechanisms that can potentially affect the particle dynamics within the structure. We present a plausible simple interpretation of the experiment in which the combination of magnetic self-pinch forces generated by the beam current together with the simultaneous reduction of the repulsive electrostatic forces due to the foils are the dominant mechanisms responsible for the observed focusing/collimation. This focusing technique could be applied to a wide variety of space-charge dominated proton and heavy ion beams and impact fields and applications, such as HEDP science, inertial confinement fusion in both fast ignition and heavy ion fusion approaches, compact laser-driven injectors for a LINAC or synchrotron, medical therapy, materials processing, etc.

  1. Damage areas due to impact craters on LDEF aluminum panels

    NASA Technical Reports Server (NTRS)

    Coombs, Cassandra R.; Atkinson, Dale R.; Allbrooks, Martha; Wagner, J. D.

    1992-01-01

    Because of its exposure time and total exposed surface area, the LDEF provides a unique opportunity to analyze the effects of the natural and man-made particle populations in low earth orbit (LEO). This study concentrated on collecting and analyzing measurements of impact craters from seven painted aluminum surfaces at different locations on the satellite. These data are being used to: (1) update the current theoretical micrometeoroid and debris models for LEO; (2) characterize the effects of the LEO micrometeoroid and debris environment of satellite components and designs; (3) help assess the probability of collision between spacecraft in LEO and already resident debris and the survivability of those spacecraft that must travel through, or reside in, LEO; and (4) help define and evaluate future debris mitigation and disposal methods. Measurements were collected from one aluminum experiment tray cover (Bay C-12), two aluminum grapple plates (Bays C-01, C-10), and four aluminum experiment sun-shields (Bay E-09), all of which were coated with thermal paint. These measurements were taken at the Facility for Optical Interpretation of Large Surfaces (FOILS) Lab at JSC. Virtually all features greater than 0.2 mm in diameter possessed a spall zone in which all of the paint was removed from the aluminum surface, and which varied in size from 2-5 crater diameters. The actual craters vary from central pits without raised rims to morphologies more typical of craters formed in aluminum under hypervelocity impact conditions for larger features. Most craters exhibit a shock zone that varies in size from approximately 1-20 crater diameters. In general, only the outermost layer of paint was affected by this impact-related phenomenon, with several impacts possessing ridge-like structures encircling the area in which this outer-most paint layer was removed. Overall, there were no noticeable penetrations or bulges on the underside of the trays. One tray from the E-09 bay exhibited a

  2. A Preliminary Foil Gas Bearing Performance Map

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Radil, Kevin C.; Bruckner, Robert J.; Howard, S. Adam

    2006-01-01

    Recent breakthrough improvements in foil gas bearing load capacity, high temperature tribological coatings and computer based modeling have enabled the development of increasingly larger and more advanced Oil-Free Turbomachinery systems. Successful integration of foil gas bearings into turbomachinery requires a step wise approach that includes conceptual design and feasibility studies, bearing testing, and rotor testing prior to full scale system level demonstrations. Unfortunately, the current level of understanding of foil gas bearings and especially their tribological behavior is often insufficient to avoid developmental problems thereby hampering commercialization of new applications. In this paper, a new approach loosely based upon accepted hydrodynamic theory, is developed which results in a "Foil Gas Bearing Performance Map" to guide the integration process. This performance map, which resembles a Stribeck curve for bearing friction, is useful in describing bearing operating regimes, performance safety margins, the effects of load on performance and limiting factors for foil gas bearings.

  3. Tilted foil polarization of radioactive beam nuclei

    NASA Astrophysics Data System (ADS)

    Goldring, Gvirol

    1992-11-01

    Tilted foil polarization has up to now been mostly applied to nuclear reaction products recoiling out of a target traversed by a primary particle beam. Being a universal phenomenon it can be applied equally well to beams of particles, primary or secondary, radioactive or other. There are however some technical considerations arising from the nature of the beam particles. Radioactive beams are associated with ground state nuclei. They usually have low nuclear spin and as a consequence-as will be shown later-low polarization. Secondary beams are usually low in intensity and do not impose any constraints on the foils they traverse; unlike intense primary heavy ion beams which, if they traverse the foils, essentially limit the foil material to carbon. We review here briefly the tilted foil polarization process and then discuss an experiment with an isomer beam. Finally we review experiments with radioactive beams, past, present and planned for the future.

  4. Recovery and distribution of incinerated aluminum packaging waste.

    PubMed

    Hu, Y; Bakker, M C M; de Heij, P G

    2011-12-01

    A study was performed into relations between physical properties of aluminum packaging waste and the corresponding aluminum scraps in bottom ash from three typical incineration processes. First, Dutch municipal solid waste incineration (MSWI) bottom ash was analyzed for the identifiable beverage can alloy scraps in the +2mm size ranges using chemical detection and X-ray fluorescence. Second, laboratory-scale pot furnace tests were conducted to investigate the relations between aluminum packaging in base household waste and the corresponding metal recovery rates. The representative packaging wastes include beverage cans, foil containers and thin foils. Third, small samples of aluminum packaging waste were incinerated in a high-temperature oven to determine leading factors influencing metal recovery rates. Packaging properties, combustion conditions, presence of magnesium and some specific contaminants commonly found in household waste were investigated independently in the high-temperature oven. In 2007, the bottom ash (+2mm fraction) from the AEB MSWI plant was estimated to be enriched by 0.1 wt.% of aluminum beverage cans scrap. Extrapolating from this number, the recovery potential of all eleven MSWI plants in the Netherlands is estimated at 720 ton of aluminum cans scrap. More than 85 wt.% of this estimate would end up in +6mm size fractions and were amenable for efficient recycling. The pot furnace tests showed that the average recovery rate of metallic aluminum typically decreases from beverage cans (93 wt.%) to foil containers (85 wt.%) to thin foils (77 wt.%). The oven tests showed that in order of decreasing impact the main factors promoting metallic aluminum losses are the packaging type, combustion temperature, residence time and salt contamination. To a lesser degree magnesium as alloying element, smaller packaging size and basic contaminations may also promote losses.

  5. Effects of the foil flatness on the stress-strain characteristics of U10Mo alloy based monolithic mini-plates

    SciTech Connect

    Hakan Ozaltun; Pavel Medvedev

    2014-11-01

    The effects of the foil flatness on stress-strain behavior of monolithic fuel mini-plates during fabrication and irradiation were studied. Monolithic plate-type fuels are a new fuel form being developed for research and test reactors to achieve higher uranium densities. This concept facilitates the use of low-enriched uranium fuel in the reactor. These fuel elements are comprised of a high density, low enrichment, U–Mo alloy based fuel foil encapsulated in a cladding material made of Aluminum. To evaluate the effects of the foil flatness on the stress-strain behavior of the plates during fabrication, irradiation and shutdown stages, a representative plate from RERTR-12 experiments (Plate L1P756) was considered. Both fabrication and irradiation processes of the plate were simulated by using actual irradiation parameters. The simulations were repeated for various foil curvatures to observe the effects of the foil flatness on the peak stress and strain magnitudes of the fuel elements. Results of fabrication simulations revealed that the flatness of the foil does not have a considerable impact on the post fabrication stress-strain fields. Furthermore, the irradiation simulations indicated that any post-fabrication stresses in the foil would be relieved relatively fast in the reactor. While, the perfectly flat foil provided the slightly better mechanical performance, overall difference between the flat-foil case and curved-foil case was not significant. Even though the peak stresses are less affected, the foil curvature has several implications on the strain magnitudes in the cladding. It was observed that with an increasing foil curvature, there is a slight increase in the cladding strains.

  6. Experimental Observations of the Electrothermal Instability on Thin Foils

    NASA Astrophysics Data System (ADS)

    Steiner, Adam; Campbell, Paul; Yager-Elorriaga, David; Jordan, Nicholas; Lau, Y. Y.; Gilgenbach, Ronald

    2016-10-01

    The electrothermal instability (ETI) arises whenever a current-carrying material has a resistivity that depends on temperature. When resistivity increases with increasing temperature, ETI causes striations to form perpendicular to the direction of current. On pulsed-power-driven, ablating metallic loads, this process can cause sections of the target to ablate earlier than the bulk material, creating a macroscopic surface perturbation on the plasma surface that can seed hydrodynamic instabilities, such as the magneto Rayleigh-Taylor (MRT) instability. Experiments have been performed to observe the self-emission of ablating planar aluminum and tantalum foils using a 12-frame ultrafast ICCD camera with 2 μm spatial resolution and 5 ns time resolution. Other diagnostics include voltage, current, and optical spectroscopy. Ablations of foils ranging from 0.4 to 2 μm in thickness are driven with a 4 kA, 600 ns risetime pulse generator. Striations of hotter, brighter material forming perpendicular to current are consistently observed. These measurements provide experimental evidence of the growth of ETI as a temperature perturbation on initially solid metal loads. This research was supported by the Department of Energy through Award DE-SC0012328, AFOSR Grant #FA9550-15-1-0419, and Sandia National Laboratories.

  7. The effects of passive foil flexibility on the energy extraction performance of an oscillating foil operating at low reduced frequencies

    NASA Astrophysics Data System (ADS)

    Totpal, Alexander D.; Siala, Firas F.; Liburdy, James A.

    2016-11-01

    With a goal to improve energy extraction efficiency from an oscillating foil, direct aerodynamic force measurements are used to study the effect of surface flexibility of an oscillating foil operating in the energy harvesting regime. The experiments are conducted in a closed-loop wind tunnel at a low reduced frequencies range of 0.04-0.06. The pitching amplitude was varied from 45 to 90 degrees and the phase shift between pitching and heaving motions was varied from 30 to 120 degrees. Three different airfoil configurations were tested: fully rigid, flexible leading edge and flexible trailing edge. In addition, phase-locked particle image velocimetry (PIV) measurements were taken at the higher efficiency cases, and are used to help interpret trends seen in the force measurement data. The timing and position of the leading edge vortex along the foil, which has been shown to be crucial to energy extraction, is investigated in order to help explain why certain operating conditions yield larger efficiencies.

  8. Benign joining of ultrafine grained aerospace aluminum alloys using nanotechnology.

    PubMed

    Longtin, Rémi; Hack, Erwin; Neuenschwander, Jürg; Janczak-Rusch, Jolanta

    2011-12-22

    Ultrafine grained aluminum alloys have restricted applicability due to their limited thermal stability. Metalized 7475 alloys can be soldered and brazed at room temperature using nanotechnology. Reactive foils are used to release heat for milliseconds directly at the interface between two components leading to a metallurgical joint without significantly heating the bulk alloy, thus preserving its mechanical properties.

  9. Magnetic shape memory effect in thin foils

    NASA Astrophysics Data System (ADS)

    Heczko, Oleg; Soroka, Aleksandr; Hannula, Simo-Pekka

    2008-07-01

    The magnetic shape memory (MSM) effect was observed in Ni-Mn-Ga freestanding thin foils down to 90μm in thickness using top-down approach. The foils were prepared by thinning the bulk crystals exhibiting MSM effect. The effect was evaluated from the magnetization curves. The significant decrease in magnetic field needed to initiate the MSM effect (magnetic field induced strain or martensite structure reorientation) was observed for the studied foils down to μ0H=0.088T or H =70kA/m. Observation suggests that the pinning of twin boundaries on the internal obstacles rather than pinning on surface lowers twin boundaries' mobility.

  10. Effects of the shape of the foil corners on the irradiation performance of U10Mo alloy based monolithic mini-plates

    SciTech Connect

    Ozaltun, Hakan; Medvedev, Pavel G

    2015-06-01

    Monolithic plate-type fuel is a fuel form being developed for high performance research and test reactors to minimize the use of enriched material. These fuel elements are comprised of a high density, low enrichment, U-Mo alloy based fuel foil, sandwiched between Zirconium liners and encapsulated in Aluminum cladding. The use of a high density fuel in a foil form presents a number of fabrication and operational concerns, such as: foil centering, flatness of the foil, fuel thickness variation, geometrical tilting, foil corner shape etc. To benchmark this new design, effects of various geometrical and operational variables on irradiation performance have been evaluated. As a part of these series of sensitivity studies, the shape of the foil corners were studied. To understand the effects of the corner shapes of the foil on thermo-mechanical performance of the plates, a behavioral model was developed for a selected plate from RERTR-12 experiments (Plate L1P785). Both fabrication and irradiation processes were simulated. Once the thermo-mechanical behavior the plate is understood for the nominal case, the simulations were repeated for two additional corner shapes to observe the changes in temperature, displacement and stress-strain fields. The results from the fabrication simulations indicated that the foil corners do not alter the post-fabrication stress-strain magnitudes. Furthermore, the irradiation simulations revealed that post-fabrication stresses of the foil would be relieved very quickly in operation. While, foils with chamfered and filleted corners yielded stresses with comparable magnitudes, they are slightly lower in magnitudes, and provided a more favorable mechanical response compared with the foil with sharp corners.

  11. Aluminum foils: the contrasting characters of hyperconjugation and steric repulsion in aluminum dimetallocenes.

    PubMed

    Compaan, Katherine R; Wilke, Jeremiah J; Schaefer, Henry F

    2011-08-31

    The novel sandwich complex Cp2*Al2I2, which was recently synthesized by Minasian and Arnold, has been characterized using ab initio and density functional methods. A large family of related compounds was also investigated. Although a few Al(II)–Al(II) bonds are known, this is the first such bond to be supported by Cp-type ligands. In addition, in the remarkable Cp4*Al4 synthesis by Roesky, Cp2*Al2I2 is the Al(II) intermediate; Cp4*Al4 is important as a precursor to novel organoaluminum species. Halogen and ligand effects on the Al–Al bond in Cp2*Al2I2 were systematically explored by studying a series of 20 Cp2*Al2I2 derivatives using density functional theory with relativistic basis sets for the halogens. Comparison was made with the focal point treatment, which uses extrapolation to estimate the full configuration interaction and complete basis set limit energy. Torsional potential energy curves, natural population analyses, and enthalpies of hydrogenation were computed. Using the focal point approach, torsional barriers were computed with 0.05 kcal mol(–1) uncertainty. The interplay of steric and electronic effects on the torsional potential energy curves, enthalpies of dehydrogenation reactions, and geometries is discussed. In species with small ligands (R = H, Me), hyperconjugative effects determine the torsional landscape, whereas steric repulsions dominate in species with Cp* alkyl ligands. Species with Cp ligands represent an intermediate case, thus providing insight into how ligands modulate the structures and properties of small metal clusters.

  12. The flow around a flapping foil

    NASA Astrophysics Data System (ADS)

    Mandujano, Francisco; Malaga, Carlos

    2016-11-01

    The flow around a two-dimensional flapping foil immersed in a uniform stream is studied numerically using a Lattice-Boltzmann model, for Reynolds numbers between 100 and 250, and flapping Strouhal numbers between 0 . 01 and 0 . 6 . The computation of the hydrodynamic force on the foil is related to the wake structure. When the foil's is fixed in space, numerical results suggest a relation between drag coefficient behaviour and the flapping frequency which determines the transition from the von Kármán to the inverted von Kármán wake. When the foil is free of translational motion up-stream swimming at constant speed is observed at certain values of the flapping Strouhal. This work was partially supported by UNAM-DGAPA-PAPIIT Grant Number IN115316.

  13. Radiative Cooling With Pigmented Polyethylene Foils

    NASA Astrophysics Data System (ADS)

    Niklasson, Gunnar A.; Eriksson, Tord S.

    1989-03-01

    Polyethylene foils containing a nonabsorbing pigment can be suitable for radiative cooling because of their high reflectance of solar radiation combined with a high transmittance in the atmospheric window region in the thermal infrared. We have studied the optical properties in the wavelength range 0.3-50 μm of extruded polyethylene foils containing various amounts of 0.23 μm diameter Ti02 particles. It appears that the foils can prevent heating of an underlying material, even when directly illuminated by the sun. The total transmittance and reflectance of the Ti02-polyethylene foils were compared with multiple scattering calculations. Lorenz-Mie theory was used to model the scattering and absorption of a single TiO2 sphere. The single scattering parameters were then introduced into the four flux theory, by which the transmittance and reflectance were calculated. We find a satisfactory agreement between theory and experiments in most cases.

  14. MUPLEX: a compact multi-layered polymer foil collector for micrometeoroids and orbital debris

    SciTech Connect

    Kearsley, A T; Graham, G A; Burchell, M J; Taylor, E A; Drolshagen, G; Chater, R J; McPhail, D

    2004-10-04

    Detailed studies of preserved hypervelocity impact residues on spacecraft multi-layer insulation foils have yielded important information about the flux of small particles from different sources in low-Earth orbit. We have extended our earlier research on impacts occurring in LEO to design and testing of a compact capture device. MULPEX (MUlti-Layer Polymer EXperiment) is simple, cheap to build, lightweight, of no power demand, easy to deploy, and optimized for the efficient collection of impact residue for analysis on return to Earth. The capture medium is a stack of very thin (8 micron and 40 micron) polyimide foils, supported on poly-tetrafluoroethylene sheet frames, surrounded by a protective aluminum casing. The uppermost foil has a very thin metallic coating for thermal protection and resistance to atomic oxygen and ultra-violet exposure. The casing provides a simple detachable interface for deployment on the spacecraft, facing into the desired direction for particle collection. On return to the laboratory, the stacked foils are separated for examination in a variable pressure scanning electron microscope, without need for surface coating. Analysis of impact residue is performed using energy dispersive X-ray spectrometers. Our laboratory experiments, utilizing buck-shot firings of analogues to micrometeoroids (35-38 micron olivine) and space debris (4 micron alumina and 1mm stainless steel) in a light gas gun, have shown that impact residue is abundant within the foil layers, and preserves a record of the impacting particle, whether of micrometer or millimeter dimensions. Penetrations of the top foil are easily recognized, and act as a proxy for dimensions of the penetrating particle. Impact may cause disruption and melting, but some residue retains sufficient crystallographic structure to show clear Raman lines, diagnostic of the original mineral.

  15. Aluminum Analysis.

    ERIC Educational Resources Information Center

    Sumrall, William J.

    1998-01-01

    Presents three problems based on the price of aluminum designed to encourage students to be cooperative and to use an investigative approach to learning. Students collect and synthesize information, analyze results, and draw conclusions. (AIM)

  16. U-Mo Foil/Cladding Interactions in Friction Stir Welded Monolithic RERTR Fuel Plates

    SciTech Connect

    D.D. Keiser; J.F. Jue; C.R. Clark

    2006-10-01

    Interaction between U-Mo fuel and Al has proven to dramatically impact the overall irradiation performance of RERTR dispersion fuels. It is of interest to better understand how similar interactions may affect the performance of monolithic fuel plates, where a uranium alloy fuel is sandwiched between aluminum alloy cladding. The monolithic fuel plate removes the fuel matrix entirely, which reduces the total surface area of the fuel that is available to react with the aluminum and moves the interface between the fuel and cladding to a colder region of the fuel plate. One of the major fabrication techniques for producing monolithic fuel plates is friction stir welding. This paper will discuss the interactions that can occur between the U-Mo foil and 6061 Al cladding when applying this fabrication technique. It has been determined that the time at high temperatures should be limited as much as is possible during fabrication or any post-fabrication treatment to reduce as much as possible the interactions between the foil and cladding. Without careful control of the fabrication process, significant interaction between the U-Mo foil and Al alloy cladding can result. The reaction layers produced from such interactions can exhibit notably different morphologies vis-à-vis those typically observed for dispersion fuels.

  17. Magnetized jets and shocks in radial foil Z-pinches: experiments and numerical simulations

    NASA Astrophysics Data System (ADS)

    Lebedev, S. V.; Suzuki-Vidal, F.; Pickworth, L. A.; Swadling, G. F.; Burdiak, G.; Skidmore, J.; Hall, G. N.; Bennett, M.; Bland, S. N.; Chittenden, J. P.; de Grouchy, P.; Derrick, J.; Hare, J.; Parker, T.; Sciortino, F.; Suttle, L.; Ciardi, A.; Rodriguez, R.; Gil, J. M.; Espinosa, G.; Hansen, E.; Frank, A.; Music, J.

    2014-10-01

    Different variations of the radial foil Z-pinch configuration have been investigated in the recent years on the MAGPIE generator (1.4 MA, 250 ns), particularly using over-massed aluminum foils with thicknesses of ~15 μm. This setup is characterized by a highly collimated, supersonic jet on the axis of the foil surrounded by low-density ablated plasma, both moving with the same axial velocity of ~60 km/s. Latest results show that the formation and collimation of the jet is directly related to toroidal magnetic field advected with the flow. We present new experimental results that include Thomson scattering measurements of plasma flow velocity and temperature, and a first study on the effect of foil material on jet formation. The effect of advected toroidal magnetic field in the plasma flow is clearly evidenced using a new experimental configuration that produces counter-streaming jets. The results are characterized by the formation of shocks in which the effect of magnetic field and radiative cooling are significant. The setup also allows controlling the polarity of the advected fields at the interaction point between the counter-streaming flows, and results from experiments and numerical simulations will be presented and discussed.

  18. Adhesive force assisted imprinting of soft solid polymer films by flexible foils.

    PubMed

    Mukherjee, Rabibrata; Sharma, Ashutosh; Gonuguntla, Manoj; Patil, Ganesh K

    2008-07-01

    We report a simple, rapid, room temperature, pressure-less and large area (approximately cm2) imprinting technique for high fidelity patterning of soft solid polymer films and surfaces like cross-linked polydimethylsiloxane (PDMS) and polyacrylamide (PAA) based hydrogels, both on planar and curved surfaces. The key element of the method is the use of patterned thin flexible foils that readily and rapidly attain a conformal contact with soft (shear modulus < 0.1 MPa) solid surfaces because of adhesive interfacial interactions. The conformal contact is established at all length scales by bending of the foil at scales larger than the feature size, in conjunction with the spontaneous elastic deformations of the surface on the scale of the features. For example, we used the protective aluminum foils of commercial data storage discs, both with or without data stored, for micron and sub-micron pattern transfer. The patterns are made permanent by UV-ozone treatment (for PDMS) or by controlled drying (for hydrogels). Interestingly, elastic contact imprinting of very thin (< 300 nm) films results in about 50% miniaturization of the original foil feature sizes. Complex two dimensional patterns could also be formed even by using a simple one dimensional master by multiple imprinting. The technique can be particularly useful for the bulk nano applications requiring routine fabrication of templates, for example, in the study of confined chemistry phenomena, nanofluidics, bio-MEMS, micro-imprinting, optical coatings and controlled dewetting.

  19. Mechanical fatigue of thin copper foil

    SciTech Connect

    Merchant, H.D.; Minor, M.G.; Liu, Y.L.

    1999-09-01

    The electrodeposited and the rolled 12 to 35 {micro}m thick copper foils are subjected to the bending/unbending strain-controlled flex fatigue over a wide range of strain amplitudes. The fatigue life is associated with an increase in electrical resistance of the specimen beyond a preassigned threshold. For each foil type, in the rolled or as-deposited as well as in the (recrystallization-like) annealed conditions, the inverse Coffin-Manson (C-M) relationship between strain amplitude ({Delta}{epsilon}/2) and fatigue life (N{sub f}) is established in the high {Delta}{epsilon}/2 (low N{sub f}) and the low {Delta}{epsilon}/2 (high N{sub f}) regimes. The N{sub f}, {Delta}{epsilon}/2, and C-M slopes (c,b) are utilized to calculate the cyclic strain hardening (n{prime}) and fatigue ductility (D{sub f}) parameters. It is shown that for a given foil thickness, an universal relationship exists between D{sub f} and the strength ({sigma}) normalized fatigue life (N{sub f}/{sigma}). The propagation of fatigue crack through the foil thickness and across the sample width is related to the unique fine grain structure for each foil type: pancaked grains for the rolled foil and equiaxed grains for the electrodeposited foil. The fatal failure corresponds to convergence of the through-thickness and the across-the-width fatigue cracks. The variations in (i) electrical resistance, (ii) mid-thickness microhardness and grain structure and (iii) dislocation configurations with fatigue are monitored. Except for a small but significant fatigue induced softening (or hardening), nonconvincing evidence of strain localization (and the associated dislocation configurations generally observed for the bulk samples) has been found.

  20. Ductile failure of a constrained metal foil

    NASA Astrophysics Data System (ADS)

    Varias, A. G.; Suo, Z.; Shih, C. F.

    A METAL foil bonded between stiff ceramic blocks may fail in a variety of ways, including de-adhesion of interfaces, cracking in the ceramics and ductile rupture of the metal. If the interface bond is strong enough to allow the foil to undergo substantial plastic deformation dimples are usually present on fracture surfaces and the nominal fracture energy is enhanced. Ductile fracture mechanisms responsible for such morphology include (i) growth of near-tip voids nucleated at second-phase particles and or interface pores, (ii) cavitation and (iii) interfacial debonding at the site of maximum stress which develops at distances of several foil thicknesses ahead of the crack tip. For a crack in a low to moderately hardening bulk metal, it is known that the maximum mean stress which develops at a distance of several crack openings ahead of the tip does not exceed about three times the yield stress. In contrast, the maximum mean stress that develops at several foil thicknesses ahead of the crack tip in a constrained metal foil can increase continuously with the applied load. Mean stress and interfacial traction of about four to six times the yield of the metal foil can trigger cavitation and/or interfacial debonding. The mechanical fields which bear on the competition between failure mechanisms are obtained by a large deformation finite element analysis. Effort is made to formulate predictive criteria indicating, for a given material system, which one of the several mechanisms operates and the relevant parameters that govern the nominal fracture work. The shielding of the crack tip in the context of ductile adhesive joints, due to the non-proportional deformation in a region of the order of the foil thickness, is also discussed.

  1. A novel monolithic LEU foil target based on a PVD manufacturing process for (99)Mo production via fission.

    PubMed

    Hollmer, Tobias; Petry, Winfried

    2016-12-01

    (99)Mo is the most widely used radioactive isotope in nuclear medicine. Its main production route is the fission of uranium. A major challenge for a reliable supply is the conversion from highly enriched uranium (HEU) to low enriched uranium (LEU). A promising candidate to realize this conversion is the cylindrical LEU irradiation target. The target consists of a uranium foil encapsulated between two coaxial aluminum cladding cylinders. This target allows a separate processing of the irradiated uranium foil and the cladding when recovering the (99)Mo. Thereby, both the costs and the volume of highly radioactive liquid waste are significantly reduced compared to conventional targets. The presented manufacturing process is based on the direct coating of the uranium on the inside of the outer cladding cylinder. This process was realized by a cylindrical magnetron enhanced physical vapor deposition (PVD) technique. The method features a highly automated process, a good quality of the resulting uranium foils and a high material utilization.

  2. Calculation of Dynamic Coefficients for Multiwound Foil Bearings

    NASA Astrophysics Data System (ADS)

    Feng, Kai; Kaneko, Shigehiko

    Dynamic performance of multiwound foil bearings with the effects of foil local deflection is investigated. The foils, separated and supported by projections on the ir surface are treated as thin plates. Deflections of the foils are solved with a finite element model. The air pressure is calculated with the Reynolds' equation by treating the lubricant as an isothermal idea gas. The effects of foils are simulated with the deflection of top foil added to the film thickness. A finite difference computer program is developed to solve the Reynolds equation and the elastic deflection equation, simultaneously. Perturbation method is used to determine the dynamic coefficients. The effects of foil deflection is discussed by comparing the dynamic coefficients of a foil bearing and a rigid bearing. Experimental data from a test rig supported by two multiwound foil bearings are used to validate this numerical solution.

  3. Additional security features for optically variable foils

    NASA Astrophysics Data System (ADS)

    Marshall, Allan C.; Russo, Frank

    1998-04-01

    For thousands of years, man has exploited the attraction and radiance of pure gold to adorn articles of great significance. Today, designers decorate packaging with metallic gold foils to maintain the prestige of luxury items such as perfumes, chocolates, wine and whisky, and to add visible appeal and value to wide range of products. However, today's products do not call for the hand beaten gold leaf of the Ancient Egyptians, instead a rapid production technology exists which makes use of accurately coated thin polymer films and vacuum deposited metallic layers. Stamping Foils Technology is highly versatile since several different layers may be combined into one product, each providing a different function. Not only can a foil bring visual appeal to an article, it can provide physical and chemical resistance properties and also protect an article from human forms of interference, such as counterfeiting, copying or tampering. Stamping foils have proved to be a highly effective vehicle for applying optical devices to items requiring this type of protection. Credit cards, bank notes, personal identification documents and more recently high value packaged items such as software and perfumes are protected by optically variable devices applied using stamping foil technology.

  4. Positron annihilation study of vacancy-type defects in Al single crystal foils with the tweed structures across the surface

    SciTech Connect

    Kuznetsov, Pavel; Cizek, Jacub Hruska, Petr; Anwad, Wolfgang; Bordulev, Yuri; Lider, Andrei; Laptev, Roman; Mironov, Yuri

    2015-10-27

    The vacancy-type defects in the aluminum single crystal foils after a series of the cyclic tensions were studied using positron annihilation. Two components were identified in the positron lifetime spectra associated with the annihilation of free positrons and positrons trapped by dislocations. With increasing number of cycles the dislocation density firstly increases and reaches a maximum value at N = 10 000 cycles but then it gradually decreases and at N = 70 000 cycles falls down to the level typical for the virgin samples. The direct evidence on the formation of a two-phase system “defective near-surface layer/base Al crystal” in aluminum foils at cyclic tension was obtained using a positron beam with the variable energy.

  5. Aluminum alloy

    NASA Technical Reports Server (NTRS)

    Blackburn, Linda B. (Inventor); Starke, Edgar A., Jr. (Inventor)

    1989-01-01

    This invention relates to aluminum alloys, particularly to aluminum-copper-lithium alloys containing at least about 0.1 percent by weight of indium as an essential component, which are suitable for applications in aircraft and aerospace vehicles. At least about 0.1 percent by weight of indium is added as an essential component to an alloy which precipitates a T1 phase (Al2CuLi). This addition enhances the nucleation of the precipitate T1 phase, producing a microstructure which provides excellent strength as indicated by Rockwell hardness values and confirmed by standard tensile tests.

  6. Sensitivity of LDEF foil analyses using ultra-low background germanium vs. large NaI(Tl) multidimensional spectrometers

    SciTech Connect

    Reeves, J.H.; Arthur, R.J.; Brodzinski, R.L.

    1992-06-01

    Cobalt foils and stainless steel samples were analyzed for induced {sup 6O}Co activity with both an ultra-low background germanium gamma-ray spectrometer and with a large NaI(Tl) multidimensional spectrometer, both of which use electronic anticoincidence shielding to reduce background counts resulting from cosmic rays. Aluminum samples were analyzed for {sup 22}Na. The results, in addition to the relative sensitivities and precisions afforded by the two methods, are presented.

  7. Sensitivity of LDEF foil analyses using ultra-low background germanium vs. large NaI(Tl) multidimensional spectrometers

    NASA Technical Reports Server (NTRS)

    Reeves, James H.; Arthur, Richard J.; Brodzinski, Ronald L.

    1993-01-01

    Cobalt foils and stainless steel samples were analyzed for induced Co-60 activity with both an ultra-low background germanium gamma-ray spectrometer and with a large NaI(Tl) multidimensional spectrometer, both of which use electronic anticoincidence shielding to reduce background counts resulting from cosmic rays. Aluminum samples were analyzed for Na-22. The results, in addition to the relative sensitivities and precisions afforded by the two methods, are presented.

  8. Performance characteristics of pitching flexible foil propulsors

    NASA Astrophysics Data System (ADS)

    Brownell, Cody; Egan, Brendan; Murray, Mark

    2014-11-01

    Performance characteristics of flexible foil propulsors are studied experimentally. The project investigates the dependence of thrust and efficiency on foil elasticity, Strouhal number, and flow velocity. The experiments took place in a large recirculating water channel, using full span flexible propulsor models to approximate a 2D geometry. The propulsor pitched about a fixed axis at its quarter chord, with a six-axis load cell measuring the forces and torques on the shaft. Propulsive efficiency is found to peak at an optimum Strouhal number for each foil tested. Varying elasticity did not produce a similar local maximum over the sampled parameter space. The ensemble data will facilitate the engineering of fish-like propulsion systems for future application of this technology.

  9. Two High-Temperature Foil Journal Bearings

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    2006-01-01

    An enlarged, high-temperature-compliant foil bearing has been built and tested to demonstrate the feasibility of such bearings for use in aircraft gas turbine engines. Foil bearings are attractive for use in some machines in which (1) speeds of rotation, temperatures, or both exceed maximum allowable values for rolling-element bearings; (2) conventional lubricants decompose at high operating temperatures; and/or (3) it is necessary or desirable not to rely on conventional lubrication systems. In a foil bearing, the lubricant is the working fluid (e.g., air or a mixture of combustion gases) in the space between the journal and the shaft in the machine in which the bearing is installed.

  10. Status of Genesis Mo-Pt Foils

    NASA Technical Reports Server (NTRS)

    Nishiizumi, K.; Allton, J. H.; Burnett, D. S.; Butterworth, A. L.; Caffee, M. W.; Clark, B.; Jurewicz, A. J. G.; Komura, K.; Westphal, A. J.; Welten, K. C.

    2005-01-01

    A total of 8,000 sq cm of Mo-coated Pt foils were exposed to solar wind for 884 days by the Genesis mission. Solar wind ions were captured in the surface of the Mo. Our objective is the measurement of long-lived radionuclides, such as Be-10, Al-26, Cl-36, and Mn-53, and short-lived radionuclides, such as Na-22 and Mn-54, in the captured sample of solar wind. The expected flux of these nuclides in the solar wind is 100 atom/sq cm yr or less. The hard landing of the SRC (Sample Return Capsule) at UTTR (Utah Test and Training Range) has resulted in contaminated and crumpled foils. Here we present a status report and revised plan for processing the foils.

  11. Computerized reduction of airborne foil impactor data

    NASA Technical Reports Server (NTRS)

    Peterson, Bret A.; Musil, Dennis J.; Smith, Paul L.

    1991-01-01

    A new technique for reducing data obtained from a foil impactor carried on the T-28 thunderstorm penetration aircraft is described. The technique employs a video-image processing system that was originally developed for satellite imagery and a computer-reduction program that was originally developed for determining cloud-size distributions to count and size particle impressions on the foil. This eliminates the tedious manual processing that has limited the usefulness of such devices, while at the same time improving objectivity. The technique has been applied to foil data acquired in thunderstorms in the southeastern United States during the Cooperative Huntsville Meteorological Experiment, where most of the particles were at least roughly spherical. Its usefulness for storms in which highly irregular or fragile ice particles predominate has yet to be established.

  12. Thrust augmentation in tandem flapping foils by foil-wake interaction

    NASA Astrophysics Data System (ADS)

    Anderson, Erik; Lauder, George

    2006-11-01

    Propulsion by pitching and heaving airfoils and hydrofoils has been a focus of much research in the field of biologically inspired propulsion. Organisms that use this sort of propulsion are self-propelled, so it is difficult to use standard experimental metrics such as thrust and drag to characterize performance. We have constructed a flapping foil robot mounted in a flume on air-bearings that allows for the determination of self-propelled speed as a metric of performance. We have used a pair of these robots to examine the impact of an upstream flapping foil on a downstream flapping foil as might apply to tandem fins of a swimming organism or in-line swimming of schooling organisms. Self-propelled speed and a force transducer confirmed significant thrust augmentation for particular foil-to-foil spacings, phase differences, and flapping frequencies. Flow visualization shows the mechanism to be related to the effective angle of attack of the downstream foil due to the structure of the wake of the upstream foil. This confirms recent computational work and the hypotheses by early investigators of fish fluid dynamics.

  13. Compressor ported shroud for foil bearing cooling

    DOEpatents

    Elpern, David G.; McCabe, Niall; Gee, Mark

    2011-08-02

    A compressor ported shroud takes compressed air from the shroud of the compressor before it is completely compressed and delivers it to foil bearings. The compressed air has a lower pressure and temperature than compressed outlet air. The lower temperature of the air means that less air needs to be bled off from the compressor to cool the foil bearings. This increases the overall system efficiency due to the reduced mass flow requirements of the lower temperature air. By taking the air at a lower pressure, less work is lost compressing the bearing cooling air.

  14. Method of high-density foil fabrication

    DOEpatents

    Blue, Craig A.; Sikka, Vinod K.; Ohriner, Evan K.

    2003-12-16

    A method for preparing flat foils having a high density includes the steps of mixing a powdered material with a binder to form a green sheet. The green sheet is exposed to a high intensity radiative source adapted to emit radiation of wavelengths corresponding to an absorption spectrum of the powdered material. The surface of the green sheet is heated while a lower sub-surface temperature is maintained. An apparatus for preparing a foil from a green sheet using a radiation source is also disclosed.

  15. Aluminum phosphide

    Integrated Risk Information System (IRIS)

    Aluminum phosphide ; CASRN 20859 - 73 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  16. Spallation Neutron Source SNS Diamond Stripper Foil Development

    SciTech Connect

    Shaw, Robert W; Plum, Michael A; Wilson, Leslie L; Feigerle, Charles S.; Borden, Michael J.; Irie, Y.; Sugai, I; Takagi, A

    2007-01-01

    Diamond stripping foils are under development for the SNS. Freestanding, flat 300 to 500 {micro}g/cm{sup 2} foils as large as 17 x 25 mm{sup 2} have been prepared. These nano-textured polycrystalline foils are grown by microwave plasma-assisted chemical vapor deposition in a corrugated format to maintain their flatness. They are mechanically supported on a single edge by a residual portion of their silicon growth substrate; fine foil supporting wires are not required for diamond foils. Six foils were mounted on the SNS foil changer in early 2006 and have performed well in commissioning experiments at reduced operating power. A diamond foil was used during a recent experiment where 15 {micro}C of protons, approximately 64% of the design value, were stored in the ring. A few diamond foils have been tested at LANSCE/PSR, where one foil was in service for a period of five months (820 C of integrated injected charge) before it was replaced. Diamond foils have also been tested in Japan at KEK (640 keV H{sup -}) where their lifetimes slightly surpassed those of evaporated carbon foils, but fell short of those for Sugai's new hybrid boron carbon (HBC) foils.

  17. Initial experimental evidence of self-collimation of target-normal-sheath-accelerated proton beam in a stack of conducting foils

    SciTech Connect

    Ni, P. A.; Bieniosek, F. M.; Logan, B. G.; Lund, S. M.; Barnard, J. J.; Bellei, C.; Cohen, R. H.; McGuffey, C.; Beg, F. N.; Kim, J.; Alexander, N.; Aurand, B.; Brabetz, C.; Neumayer, P.; Roth, M.

    2013-08-15

    Phenomena consistent with self-collimation (or weak self-focusing) of laser target-normal-sheath-accelerated protons was experimentally observed for the first time, in a specially engineered structure (“lens”) consisting of a stack of 300 thin aluminum foils separated by 50 μm vacuum gaps. The experiments were carried out in a “passive environment,” i.e., no external fields applied, neutralization plasma or injection of secondary charged particles was imposed. Experiments were performed at the petawatt “PHELIX” laser user facility (E = 100 J, Δt = 400 fs, λ = 1062 nm) at the “Helmholtzzentrum für Schwerionenforschung–GSI” in Darmstadt, Germany. The observed rms beam spot reduction depends inversely on energy, with a focusing degree decreasing monotonically from 2 at 5.4 MeV to 1.5 at 18.7 MeV. The physics inside the lens is complex, resulting in a number of different mechanisms that can potentially affect the particle dynamics within the structure. We present a plausible simple interpretation of the experiment in which the combination of magnetic self-pinch forces generated by the beam current together with the simultaneous reduction of the repulsive electrostatic forces due to the foils are the dominant mechanisms responsible for the observed focusing/collimation. This focusing technique could be applied to a wide variety of space-charge dominated proton and heavy ion beams and impact fields and applications, such as HEDP science, inertial confinement fusion in both fast ignition and heavy ion fusion approaches, compact laser-driven injectors for a Linear Accelerator (LINAC) or synchrotron, medical therapy, materials processing, etc.

  18. Initial experimental evidence of self-collimation of target-normal-sheath-accelerated proton beam in a stack of conducting foils

    NASA Astrophysics Data System (ADS)

    Ni, P. A.; Lund, S. M.; McGuffey, C.; Alexander, N.; Aurand, B.; Barnard, J. J.; Beg, F. N.; Bellei, C.; Bieniosek, F. M.; Brabetz, C.; Cohen, R. H.; Kim, J.; Neumayer, P.; Roth, M.; Logan, B. G.

    2013-08-01

    Phenomena consistent with self-collimation (or weak self-focusing) of laser target-normal-sheath-accelerated protons was experimentally observed for the first time, in a specially engineered structure ("lens") consisting of a stack of 300 thin aluminum foils separated by 50 μm vacuum gaps. The experiments were carried out in a "passive environment," i.e., no external fields applied, neutralization plasma or injection of secondary charged particles was imposed. Experiments were performed at the petawatt "PHELIX" laser user facility (E = 100 J, Δt = 400 fs, λ = 1062 nm) at the "Helmholtzzentrum für Schwerionenforschung-GSI" in Darmstadt, Germany. The observed rms beam spot reduction depends inversely on energy, with a focusing degree decreasing monotonically from 2 at 5.4 MeV to 1.5 at 18.7 MeV. The physics inside the lens is complex, resulting in a number of different mechanisms that can potentially affect the particle dynamics within the structure. We present a plausible simple interpretation of the experiment in which the combination of magnetic self-pinch forces generated by the beam current together with the simultaneous reduction of the repulsive electrostatic forces due to the foils are the dominant mechanisms responsible for the observed focusing/collimation. This focusing technique could be applied to a wide variety of space-charge dominated proton and heavy ion beams and impact fields and applications, such as HEDP science, inertial confinement fusion in both fast ignition and heavy ion fusion approaches, compact laser-driven injectors for a Linear Accelerator (LINAC) or synchrotron, medical therapy, materials processing, etc.

  19. Identification of Possible Interstellar Dust Impact Craters on Stardust Foil I033N,1

    NASA Astrophysics Data System (ADS)

    Ansari, A.; ISPE Team; 29,000 Stardust@home Dusters

    2011-12-01

    The Interstellar Dust Collector onboard NASA's Stardust Mission - the first to return solid extraterrestrial material to Earth from beyond the Moon - was exposed to the interstellar dust stream for a total of 229 days prior to the spacecraft's return in 2006 [1]. Aluminum foils and aerogel tiles on the collector may have captured the first samples of contemporary interstellar dust. Interstellar Preliminary Examination (ISPE) focuses in part on crater identification and analysis of residue within the craters to determine the nature and origin of the impacting particles. Thus far, ISPE has focused on nine foils and found a total of 20 craters. The number density of impact craters on the foils exceeds by far estimates made from interstellar flux calculations [2]. To identify craters, foil I1033N,1 was scanned with the Field Museum's Evo 60 Scanning Electron Microscope (SEM) at a resolution of 52 nm/pixel with a 15 kV and 170-240 pA beam. Contamination was monitored according to the ISPE protocol: four 4 μm × 3 μm areas of C layers of different thicknesses on a Stardust-type Al foil were irradiated 20 times for 50 s each, while the C and Al signals were recorded with energy-dispersive X-ray spectroscopy (EDS). The C/Al ratio did not increase after 20 repetitions on each of the four areas. The same experiment repeated 7 months later yielded identical results. Thus, analysis with the SEM results in no detectable contamination. Crater candidates were manually selected from SEM images, then reimaged at higher resolution (17 nm/pixel) in order to eliminate false detections. The foil was then sent to Washington University for Auger Nanoprobe elemental analysis of crater 11_175 (diam. 1.1 μm), and to the Naval Research Laboratory for focused ion beam work and transmission electron microscopy and EDS. Twelve crater candidates (diam. 0.28 - 1.1 μm), both elliptical and circular, were identified. The number density of craters on foil 1033N is 15.8 cm^-2. Auger measurements

  20. The Fluid Foil: The Seventh Simple Machine

    ERIC Educational Resources Information Center

    Mitts, Charles R.

    2012-01-01

    A simple machine does one of two things: create a mechanical advantage (lever) or change the direction of an applied force (pulley). Fluid foils are unique among simple machines because they not only change the direction of an applied force (wheel and axle); they convert fluid energy into mechanical energy (wind and Kaplan turbines) or vice versa,…

  1. Metallic foil-assisted laser cell printing.

    PubMed

    Lin, Yafu; Huang, Yong; Chrisey, Douglas B

    2011-02-01

    Laser direct-write technology such as modified laser-induced forward transfer (LIFT) is emerging as a revolutionary technology for biological construct fabrication. While many modified LIFT-based cell direct writing successes have been achieved, possible process-induced cell injury and death is still a big hurdle for modified LIFT-based cell direct writing to be a viable technology. The objective of this study is to propose metallic foil-assisted LIFT using a four-layer structure to achieve better droplet size control and increase cell viability in direct writing of human colon cancer cells (HT-29). The proposed four layers include a quartz disk, a sacrificial and adhesive layer, a metallic foil, and a cell suspension layer. The bubble formation-induced stress wave is responsible for droplet formation. It is found that the proposed metallic foil-assisted LIFT approach is an effective cell direct-write technology and provides better printing resolution and high post-transfer cell viability when compared with other conventional modified LIFT technologies such as matrix-assisted pulsed-laser evaporation direct-write; at the same time, the possible contamination from the laser energy absorbing material is minimized using a metallic foil.

  2. Hydrogen and Palladium Foil: Two Classroom Demonstrations

    ERIC Educational Resources Information Center

    Klotz, Elsbeth; Mattson, Bruce

    2009-01-01

    In these two classroom demonstrations, students observe the reaction between H[subscript 2] gas and Pd foil. In the first demonstration, hydrogen and palladium combine within one minute at 1 atm and room temperature to yield the non-stoichiometric, interstitial hydride with formula close to the maximum known value, PdH[subscript 0.7]. In the…

  3. Indium Foil Serves As Thermally Conductive Gasket

    NASA Technical Reports Server (NTRS)

    Eastman, G. Yale; Dussinger, Peter M.

    1993-01-01

    Indium foil found useful as gasket to increase thermal conductance between bodies clamped together. Deforms to fill imperfections on mating surfaces. Used where maximum temperature in joint less than melting temperature of indium. Because of low melting temperature of indium, most useful in cryogenic applications.

  4. Strong field electrodynamics of a thin foil

    SciTech Connect

    Bulanov, Sergei V.; Esirkepov, Timur Zh.; Kando, Masaki; Bulanov, Stepan S.; Rykovanov, Sergey G.; Pegoraro, Francesco

    2013-12-15

    Exact solutions describing the nonlinear electrodynamics of a thin double layer foil are presented. These solutions correspond to a broad range of problems of interest for the interaction of high intensity laser pulses with overdense plasmas, such as frequency upshifting, high order harmonic generation, and high energy ion acceleration.

  5. Thermal Sensitive Foils in Physics Experiments

    ERIC Educational Resources Information Center

    Bochnícek, Zdenek; Konecný, Pavel

    2014-01-01

    The paper describes a set of physics demonstration experiments where thermal sensitive foils are used for the detection of the two dimensional distribution of temperature. The method is used for the demonstration of thermal conductivity, temperature change in adiabatic processes, distribution of electromagnetic radiation in a microwave oven and…

  6. Thermal sensitive foils in physics experiments

    NASA Astrophysics Data System (ADS)

    Bochníček, Zdeněk; Konečný, Pavel

    2014-07-01

    The paper describes a set of physics demonstration experiments where thermal sensitive foils are used for the detection of the two dimensional distribution of temperature. The method is used for the demonstration of thermal conductivity, temperature change in adiabatic processes, distribution of electromagnetic radiation in a microwave oven and detection of resonant acoustic oscillations in a Rubens’ tube.

  7. Strong field electrodynamics of a thin foil

    NASA Astrophysics Data System (ADS)

    Bulanov, S. S.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Rykovanov, S.; Pegoraro, F.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2017-03-01

    A new one-dimensional analytical model of a thin double layer foil interaction with a laser pulse is presented. It is based on one-dimensional electrodynamics. This model can be used for the study of high intensity laser pulse interactions with overdense plasmas, leading to frequency upshifting, high order harmonic generation, and ion acceleration in different regimes.

  8. 6Li foil thermal neutron detector

    SciTech Connect

    Ianakiev, Kiril D; Swinhoe, Martyn T; Favalli, Andrea; Chung, Kiwhan; Macarthur, Duncan W

    2010-01-01

    In this paper we report on the design of a multilayer thermal neutron detector based on {sup 6}Li reactive foil and thin film plastic scintillators. The {sup 6}Li foils have about twice the intrinsic efficiency of {sup 10}B films and about four times higher light output due to a unique combination of high energy of reaction particles, low self absorption, and low ionization density of tritons. The design configuration provides for double sided readout of the lithium foil resulting in a doubling of the efficiency relative to a classical reactive film detector and generating a pulse height distribution with a valley between neutron and gamma signals similar to {sup 3}He tubes. The tens of microns thickness of plastic scintillator limits the energy deposited by gamma rays, which provides the necessary neutron/gamma discrimination. We used MCNPX to model a multilayer Li foil detector design and compared it with the standard HLNCC-II (18 {sup 3}He tubes operated at 4 atm). The preliminary results of the {sup 6}Li configuration show higher efficiency and one third of the die-away time. These properties, combined with the very short dead time of the plastic scintillator, offer the potential of a very high performance detector.

  9. Transverse Emittance Reduction with Tapered Foil

    SciTech Connect

    Jiao, Yi; Chao, Alex; Cai, Yunhai; /SLAC

    2011-12-09

    The idea of reducing transverse emittance with tapered energy-loss foil is proposed by J.M. Peterson in 1980s and recently by B. Carlsten. In this paper, we present the physical model of tapered energy-loss foil and analyze the emittance reduction using the concept of eigen emittance. The study shows that, to reduce transverse emittance, one should collimate at least 4% of particles which has either much low energy or large transverse divergence. The multiple coulomb scattering is not trivial, leading to a limited emittance reduction ratio. Small transverse emittances are of essential importance for the accelerator facilities generating free electron lasers, especially in hard X-ray region. The idea of reducing transverse emittance with tapered energy-loss foil is recently proposed by B. Carlsten [1], and can be traced back to J.M. Peterson's work in 1980s [2]. Peterson illustrated that a transverse energy gradient can be produced with a tapered energy-loss foil which in turn leads to transverse emittance reduction, and also analyzed the emittance growth from the associated multiple coulomb scattering. However, what Peterson proposed was rather a conceptual than a practical design. In this paper, we build a more complete physical model of the tapered foil based on Ref. [2], including the analysis of the transverse emittance reduction using the concept of eigen emittance and confirming the results by various numerical simulations. The eigen emittance equals to the projected emittance when there is no cross correlation in beam's second order moments matrix [3]. To calculate the eigen emittances, it requires only to know the beam distribution at the foil exit. Thus, the analysis of emittance reduction and the optics design of the subsequent beam line section can be separated. In addition, we can combine the effects of multiple coulomb scattering and transverse energy gradient together in the beam matrix and analyze their net effect. We find that,when applied to an

  10. Tungsten foil laminate for structural divertor applications - Joining of tungsten foils

    NASA Astrophysics Data System (ADS)

    Reiser, Jens; Rieth, Michael; Möslang, Anton; Dafferner, Bernhard; Hoffmann, Jan; Mrotzek, Tobias; Hoffmann, Andreas; Armstrong, D. E. J.; Yi, Xiaoou

    2013-05-01

    This paper is the fourth in our series on tungsten laminates. The aim of this paper is to discuss laminate synthesis, meaning the joining of tungsten foils. It is obvious that the properties of the tungsten laminate strongly depend on the combination of (i) interlayer and (ii) joining technology, as this combination defines (i) the condition of the tungsten foil after joining (as-received or recrystallised) as well as (ii) the characteristics of the interface between the tungsten foil and the interlayer (wettability or diffusion leading to a solid solution or the formation of intermetallics). From the example of tungsten laminates joined by brazing with (i) an eutectic silver copper brazing filler, (ii) copper, (iii) titanium, and (iv) zirconium, the microstructure will be discussed, with special focus on the interface. Based on our assumptions of the mechanism of the extraordinary ductility of tungsten foil we present three syntheses strategies and make recommendations for the synthesis of high temperature tungsten laminates.

  11. Scaling laws for radial foil bearings

    NASA Astrophysics Data System (ADS)

    Honavara Prasad, Srikanth

    The effects of fluid pressurization, structural deformation of the compliant members and heat generation in foil bearings make the design and analysis of foil bearings very complicated. The complex fluid-structural-thermal interactions in foil bearings also make modeling efforts challenging because these phenomena are governed by highly non-linear partial differential equations. Consequently, comparison of various bearing designs require detailed calculation of the flow fields (velocities, pressures), bump deflections (structural compliance) and heat transfer phenomena (viscous dissipation in the fluid, frictional heating, temperature profile etc.,) resulting in extensive computational effort (time/hardware). To obviate rigorous computations and aid in feasibility assessments of foil bearings of various sizes, NASA developed the "rule of thumb" design guidelines for estimation of journal bearing load capacity. The guidelines are based on extensive experimental data. The goal of the current work is the development of scaling laws for radial foil bearings to establish an analytical "rule of thumb" for bearing clearance and bump stiffness. The use of scale invariant Reynolds equation and experimentally observed NASA "rule of thumb" yield scale factors which can be deduced from first principles. Power-law relationships between: a. Bearing clearance and bearing radius, and b. bump stiffness and bearing radius, are obtained. The clearance and bump stiffness values obtained from scaling laws are used as inputs for Orbit simulation to study various cases. As the clearance of the bearing reaches the dimensions of the material surface roughness, asperity contact breaks the fluid film which results in wear. Similarly, as the rotor diameter increases (requiring larger bearing diameters), the load capacity of the fluid film should increase to prevent dry rubbing. This imposes limits on the size of the rotor diameter and consequently bearing diameter. Therefore, this thesis aims

  12. 200 kj copper foil fuses. Final report

    SciTech Connect

    McClenahan, C.R.; Goforth, J.H.; Degnan, J.H.; Henderson, R.M.; Janssen, W.H.

    1980-04-01

    A 200-kJ, 50-kV capacitor bank has been discharged into 1-mil-thick copper foils immersed in fine glass beads. These foils ranged in length from 27 to 71 cm and in width from 15 to 40 cm. Voltage spikes of over 250 kV were produced by the resulting fuse behavior of the foil. Moreover, the current turned off at a rate that was over 6 times the initial bank dI/dt. Full widths at half maxima for the voltage and dI/dt spikes were about 0.5 microsec, with some as short as 300 nanosec. Electrical breakdown was prevented in all but one size fuze with maximum applied fields of 7 kV/cm. Fuses that were split into two parallel sections have been tested, and the effects relative to one-piece fuses are much larger than would be expected on the basis of inductance differences alone. A resistivity model for copper foil fuses, which differs from previous work in that it includes a current density dependence, has been devised. Fuse behavior is predicted with reasonable accuracy over a wide range of foil sizes by a quasi-two-dimensional fuse code that incorporates this resistivity model. A variation of Maisonnier's method for predicting optimum fuze size has been derived. This method is valid if the risetime of the bank exceeds 3 microsec, in which case it can be expected to be applicable over a wide range of peak current densities.

  13. Satellite and Opacity Effects on Resonance Line Shapes Produced from Short-Pulse Laser Heated Foils

    SciTech Connect

    Shepherd, R; Audebert, P; Chen, H-K; Fournier, K B; Peyreusse, O; Moon, S; Lee, R W; Price, D; Klein, L; Gauthier, J C; Springer, P

    2002-12-03

    We measure the He-like, time-resolved emission from thin foils consisting of 250 {angstrom} of carbon-250 {angstrom} of aluminum and 500 {angstrom} aluminum illuminated with a 150 fs laser pulse at an intensity of 1 x 10{sup 19} W/cm{sup 2}. Dielectronic satellite contributions to the 1s{sup 2}-1s2p({sup 1}P), 1s{sup 2}-1s3p({sup 1}P), and 1s{sup 2}1s4p({sup 1}P) line intensities are modeled using the configuration averaged code AVERROES and is found to be significant for all three resonance lines. The contribution of opacity broadening is inferred from the data and found to be significant only in the 1s{sup 2}-1s2p({sup 1}P).

  14. Liquid Oxygen Rotating Friction Ignition Testing of Aluminum and Titanium with Monel and Inconel for Rocket Engine Propulsion System Contamination Investigation

    NASA Technical Reports Server (NTRS)

    Peralta, S.; Rosales, Keisa R.; Stoltzfus, Joel M.

    2009-01-01

    Metallic contaminant was found in the liquid oxygen (LOX) pre-valve screen of the shuttle main engine propulsion system on two orbiter vehicles. To investigate the potential for an ignition, NASA Johnson Space Center White Sands Test Facility performed (modified) rotating friction ignition testing in LOX. This testing simulated a contaminant particle in the low-pressure oxygen turbo pump (LPOTP) and the high-pressure oxygen turbo pump (HPOTP) of the shuttle main propulsion system. Monel(R) K-500 and Inconel(R) 718 samples represented the LPOTP and HPOTP materials. Aluminum foil tape and titanium foil represented the contaminant particles. In both the Monel(R) and Inconel(R) material configurations, the aluminum foil tape samples did not ignite after 30 s of rubbing. In contrast, all of the titanium foil samples ignited regardless of the rubbing duration or material configuration. However, the titanium foil ignitions did not propagate to the Monel and Inconel materials.

  15. Nuclear target foil fabrication for the Romano Event

    SciTech Connect

    Weed, J.W.; Romo, J.G. Jr.; Griggs, G.E.

    1984-06-19

    The Vacuum Processes Lab, of LLNL's M.E. Dept. - Material Fabrication Division, was requested to provide 250 coated Parylene target foils for a nuclear physics experiment titled the ROMANO Event. Due to the developmental nature of some of the fabrication procedures, approximately 400 coated foils were produced to satisfy the event's needs. The foils were used in the experiment as subkilovolt x-ray, narrow band pass filters, and wide band ultraviolet filters. This paper is divided into three sections describing: (1) nuclear target foil fabrication, (2) Parylene substrate preparation and production, and (3) foil and substrate inspections.

  16. The impact of Hall physics on magnetized plasma jets produced by radial foil configurations

    NASA Astrophysics Data System (ADS)

    Gourdain, P.-A.; Greenly, J. B.; Hammer, D. A.; Kusse, B. R.; Schrafel, P. C.; Seyler, C. E.; Bland, S. N.; Hall, G. N.; Lebedev, S. V.; Suzuki-Vidal, F.

    2012-10-01

    Although no one argues that plasma resistivity is important to include in the astrophysical simulations, based upon experiments with magnetized jets on pulsed power machines in the laboratory, we believe it may also be important to include the Hall term in the generalized Ohm's law in astrophysics simulation codes. In this talk, experiments carried out at Cornell University and at Imperial College on 1 to 1.5 MA pulsed power generators feature a plasma disk and a collimated, axial plasma jet with large Re (10^5) and Rem (10^3). The plasma jet is generated by ablation from electrical currents, which flow in a thin aluminum foil and converge to a central multi-pin cathode located under the foil. A twist in the pins produce the axial magnetic field necessary to magnetized the jet. It was observed that changing the polarity of the current alters drastically the plasma dynamics, an indication of the importance of the Hall effect in plasmas produced by radial foils. The overall agreement between experimental results and numerical simulations indicates that PERSEUS accounts properly for Hall physics in this geometry and plasma parameter range. Scaling to astrophysical occurrences via numerical simulations should highlight how Hall physics affects the dynamics of larger accretion disks.

  17. Modeling dissolution in aluminum alloys

    NASA Astrophysics Data System (ADS)

    Durbin, Tracie Lee

    2005-07-01

    Aluminum and its alloys are used in many aspects of modern life, from soda cans and household foil to the automobiles and aircraft in which we travel. Aluminum alloy systems are characterized by good workability that enables these alloys to be economically rolled, extruded, or forged into useful shapes. Mechanical properties such as strength are altered significantly with cold working, annealing, precipitation-hardening, and/or heat-treatments. Heat-treatable aluminum alloys contain one or more soluble constituents such as copper, lithium, magnesium, silicon and zinc that individually, or with other elements, can form phases that strengthen the alloy. Microstructure development is highly dependent on all of the processing steps the alloy experiences. Ultimately, the macroscopic properties of the alloy depend strongly on the microstructure. Therefore, a quantitative understanding of the microstructural changes that occur during thermal and mechanical processing is fundamental to predicting alloy properties. In particular, the microstructure becomes more homogeneous and secondary phases are dissolved during thermal treatments. Robust physical models for the kinetics of particle dissolution are necessary to predict the most efficient thermal treatment. A general dissolution model for multi-component alloys has been developed using the front-tracking method to study the dissolution of precipitates in an aluminum alloy matrix. This technique is applicable to any alloy system, provided thermodynamic and diffusion data are available. Treatment of the precipitate interface is explored using two techniques: the immersed-boundary method and a new technique, termed here the "sharp-interface" method. The sharp-interface technique is based on a variation of the ghost fluid method and eliminates the need for corrective source terms in the characteristic equations. In addition, the sharp-interface method is shown to predict the dissolution behavior of precipitates in aluminum

  18. Focused Ion Beam Recovery of Hypervelocity Impact Residue in Experimental Craters on Metallic Foils.

    SciTech Connect

    Graham, G A; Teslich, N; Dai, Z R; Bradley, J P; Kearsley, A T; Horz, F

    2005-11-04

    The Stardust sample return capsule will return to Earth in January 2006 with primitive debris collected from Comet 81P/Wild-2 during the fly-by encounter in 2004. In addition to the cometary particles embedded in low-density silica aerogel, there will be microcraters preserved in the Al foils (1100 series; 100 {micro}m thick) that are wrapped around the sample tray assembly. Soda lime spheres ({approx}49 {micro}m in diameter) have been accelerated with a Light Gas Gun into flight-grade Al foils at 6.35 km s{sup -1} to simulate the capture of cometary debris. The experimental craters have been analyzed using scanning electron microscopy (SEM) and x-ray energy dispersive spectroscopy (EDX) to locate and characterize remnants of the projectile material remaining within the craters. In addition, ion beam induced secondary electron imaging has proven particularly useful in identifying areas within the craters that contain residue material. Finally, high-precision focused ion beam (FIB) milling has been used to isolate and then extract an individual melt residue droplet from the interior wall of an impact. This enabled further detailed elemental characterization, free from the background contamination of the Al foil substrate. The ability to recover ''pure'' melt residues using FIB will significantly extend the interpretations of the residue chemistry preserved in the Al foils returned by Stardust.

  19. Focused Ion Beam Recovery of Hypervelocity Impact Residue in Experimental Craters on Metallic Foils

    NASA Technical Reports Server (NTRS)

    Graham, G. A.; Teslich, N.; Dai, Z. R.; Bradley, J. P.; Kearsley, A. T.; Horz, F.

    2006-01-01

    The Stardust sample return capsule will return to Earth in January 2006 with primitive debris collected from Comet 81P/Wild-2 during the fly-by encounter in 2004. In addition to the cometary particles embedded in low-density silica aerogel, there will be microcraters preserved in the Al foils (1100 series; 100 micrometers thick) that are wrapped around the sample tray assembly. Soda lime spheres (approximately 49 m in diameter) have been accelerated with a light-gas-gun into flight-grade Al foils at 6.35 km s(sup -1) to simulate the potential capture of cometary debris. The preserved crater penetrations have been analyzed using scanning electron microscopy (SEM) and x-ray energy dispersive spectroscopy (EDX) to locate and characterize remnants of the projectile material remaining within the craters. In addition, ion beam induced secondary electron imaging has proven particularly useful in identifying areas within the craters that contain residue material. Finally, high-precision focused ion beam (FIB) milling has been used to isolate and then extract an individual melt residue droplet from the interior wall of an impact penetration. This enabled further detailed elemental characterization, free from the background contamination of the Al foil substrate. The ability to recover pure melt residues using FIB will significantly extend the interpretations of the residue chemistry preserved in the Al foils returned by Stardust.

  20. Composite metal foil and ceramic fabric materials

    DOEpatents

    Webb, Brent J.; Antoniak, Zen I.; Prater, John T.; DeSteese, John G.

    1992-01-01

    The invention comprises new materials useful in a wide variety of terrestrial and space applications. In one aspect, the invention comprises a flexible cloth-like material comprising a layer of flexible woven ceramic fabric bonded with a layer of metallic foil. In another aspect, the invention includes a flexible fluid impermeable barrier comprising a flexible woven ceramic fabric layer having metal wire woven therein. A metallic foil layer is incontinuously welded to the woven metal wire. In yet another aspect, the invention includes a material comprising a layer of flexible woven ceramic fabric bonded with a layer of an organic polymer. In still another aspect, the invention includes a rigid fabric structure comprising a flexible woven ceramic fabric and a resinous support material which has been hardened as the direct result of exposure to ultraviolet light. Inventive methods for producing such material are also disclosed.

  1. Composite metal foil and ceramic fabric materials

    DOEpatents

    Webb, B.J.; Antoniak, Z.I.; Prater, J.T.; DeSteese, J.G.

    1992-03-24

    The invention comprises new materials useful in a wide variety of terrestrial and space applications. In one aspect, the invention comprises a flexible cloth-like material comprising a layer of flexible woven ceramic fabric bonded with a layer of metallic foil. In another aspect, the invention includes a flexible fluid impermeable barrier comprising a flexible woven ceramic fabric layer having metal wire woven therein. A metallic foil layer is incontinuously welded to the woven metal wire. In yet another aspect, the invention includes a material comprising a layer of flexible woven ceramic fabric bonded with a layer of an organic polymer. In still another aspect, the invention includes a rigid fabric structure comprising a flexible woven ceramic fabric and a resinous support material which has been hardened as the direct result of exposure to ultraviolet light. Inventive methods for producing such material are also disclosed. 11 figs.

  2. FoilSim: Basic Aerodynamics Software Created

    NASA Technical Reports Server (NTRS)

    Peterson, Ruth A.

    1999-01-01

    FoilSim is interactive software that simulates the airflow around various shapes of airfoils. The graphical user interface, which looks more like a video game than a learning tool, captures and holds the students interest. The software is a product of NASA Lewis Research Center s Learning Technologies Project, an educational outreach initiative within the High Performance Computing and Communications Program (HPCCP).This airfoil view panel is a simulated view of a wing being tested in a wind tunnel. As students create new wing shapes by moving slider controls that change parameters, the software calculates their lift. FoilSim also displays plots of pressure or airspeed above and below the airfoil surface.

  3. Brazing Inconel 625 Using the Copper Foil

    NASA Astrophysics Data System (ADS)

    Chen, Wen-Shiang; Wang, Cheng-Yen; Shiue, Ren-Kae

    2013-12-01

    Brazing Inconel 625 (IN-625) using the copper foil has been investigated in this research. The brazed joint is composed of nanosized CrNi3 precipitates and Cr/Mo/Nb/Ni quaternary compound in the Cu/Ni-rich matrix. The copper filler 50 μm in thickness is enough for the joint filling. However, the application of Cu foil 100 μm in thickness has little effect on the shear strength of the brazed joint. The specimen brazed at 1433 K (1160 °C) for 1800 seconds demonstrates the best shear strength of 470 MPa, and its fractograph is dominated by ductile dimple fracture with sliding marks. Decreasing the brazing temperature slightly decreases the shear strength of the brazed joint due to the presence of a few isolated solidification shrinkage voids smaller than 15 μm. Increasing the brazing temperature, especially for the specimen brazed at 1473 K (1200 °C), significantly deteriorates the shear strength of the joint below 260 MPa because of coalescence of isothermal solidification shrinkage voids in the joint. The Cu foil demonstrates potential in brazing IN-625 for industrial application.

  4. Beam-Foil Spectroscopy - Quo Vadis?

    SciTech Connect

    Trabert, E

    2008-05-26

    Beam-foil spectroscopy after 45 years: what has been realized of the promises, what is the state of the art, what is the status of the field, what present atomic physics problems should the technique be applied to, where can it be done? Will it be done? Beam-foil spectroscopy and its sibling techniques have been outstandingly productive tools of atomic physics, providing both important data and insight. For some forty years, the developments have led to improvements in working range and reliability, and catalogues of desirable further measurements can be formulated. However, most of the key persons who have carried out and directed much of the development effort are nearing retirement, and with them the leading facilities. it is thus not likely that many of the desirable BFS projects discussed will presently be pursued. High-Z element, high-charge state spectroscopy and some specific long-lived level lifetime measurements will, however, be taken over by electron beam ion traps, and heavy-ion storage rings will contribute some important benchmark measurements on electric-dipole forbidden or hyperfine-induced transitions. Beam-foil spectroscopy can still be expected to solve a number of interesting atomic physics questions, but as a technique, at present, it has dropped from fashion and support.

  5. The Effect of Journal Roughness and Foil Coatings on the Performance of Heavily Loaded Foil Air Bearings

    NASA Technical Reports Server (NTRS)

    Radil, Kevin C.; DellaCorte, Christopher

    2001-01-01

    Foil air bearing load capacity tests were conducted to investigate if a solid lubricant coating applied to the surface of the bearing's top foil can function as a break-in coating. Two foil coating materials, a conventional soft polymer film (polyimide) and a hard ceramic (alumina), were independently evaluated against as-ground and worn (run-in) journals coated with NASA PS304, a high-temperature solid lubricant composite coating. The foil coatings were evaluated at journal rotational speeds of 30,000 rpm and at 25 C. Tests were also performed on a foil bearing with a bare (uncoated) nickel-based superalloy top foil to establish a baseline for comparison. The test results indicate that the presence of a top foil solid lubricant coating is effective at increasing the load capacity performance of the foil bearing. Compared to the uncoated baseline, the addition of the soft polymer coating on the top foil increased the bearing load coefficient by 120% when operating against an as-ground journal surface and 85 percent against a run-in journal surface. The alumina coating increased the load coefficient by 40% against the as-ground journal but did not have any affect when the bearing was operated with the run-in journal. The results suggest that the addition of solid lubricant films provide added lubrication when the air film is marginal indicating that as the load capacity is approached foil air bearings transition from hydrodynamic to mixed and boundary lubrication.

  6. Extreme extensibility of copper foil under compound forming conditions.

    PubMed

    Yu, Qingbo; Liu, Xianghua; Tang, Delin

    2013-12-19

    A copper foil with an extreme extensibility up to 43,684% was obtained without any intermediate annealing by means of asynchronous rolling with high tension. It was found that under the combination of compression, shearing and tension, the copper foil represents a wonderful phenomenon. As the reduction increases, the specimen hardness increases up to a peak value 138 HV0.05 when the foil thickness rolled to around 100 μm, and then it decreases down to 78 HV0.05 when the foil thickness rolled to the final size 19 μm. It tells us that the strain-softening effect occurs when the foil thickness is rolled down to a threshold level. The experimental results bring us some fresh ideas different with the traditional understanding on the strain-hardening mechanism of metals, which provides an experimental basis to establish the forming mechanism of the thin foil.

  7. Microfabricated Segmented-Involute-Foil Regenerator for Stirling Engines

    NASA Technical Reports Server (NTRS)

    Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Qiu, Songgang; Wood, Gary; Kelly, Kevin; McLean, Jeffrey

    2010-01-01

    An involute-foil regenerator was designed, microfabricated, and tested in an oscillating-flow test rig. The concept consists of stacked involute-foil nickel disks (see figure) microfabricated via a lithographic process. Test results yielded a performance of about twice that of the 90-percent random-fiber currently used in small Stirling converters. The segmented nature of the involute- foil in both the axial and radial directions increases the strength of the structure relative to wrapped foils. In addition, relative to random-fiber regenerators, the involute-foil has a reduced pressure drop, and is expected to be less susceptible to the release of metal fragments into the working space, thus increasing reliability. The prototype nickel involute-foil regenerator was adequate for testing in an engine with a 650 C hot-end temperature. This is lower than that required by larger engines, and high-temperature alloys are not suited for the lithographic microfabrication approach.

  8. Design for aluminum recycling

    SciTech Connect

    Not Available

    1993-10-01

    This article describes the increasing use of aluminum in automobiles and the need to recycle to benefit further growth of aluminum applications by assuring an economical, high-quality source of metal. The article emphasizes that coordination of material specifications among designers can raise aluminum scrap value and facilitate recycling. Applications of aluminum in automobile construction are discussed.

  9. Developing NanoFoil-Heated Thin-Film Thermal Battery

    DTIC Science & Technology

    2013-09-01

    NanoFoil-Heated Thin- Film Thermal Battery ..........................................6 3. Results and Discussion 8 3.1 Regulation of Skin ...Developing NanoFoil-Heated Thin- Film Thermal Battery by Michael S. Ding, Frank C. Krieger, and Jeffrey A. Swank ARL-TR-6664 September...TR-6664 September 2013 Developing NanoFoil-Heated Thin- Film Thermal Battery Michael S. Ding, Frank C. Krieger, and Jeffrey A. Swank

  10. Pulsed Electric Discharge Laser Technology. Electron Beam Window Foil Material.

    DTIC Science & Technology

    1984-01-01

    6.0 INTERFEROMETRIC MEASUREMENT OF FOIL MOVEMENT A simple Michelson interferometer was used to measure foil movement on the test rig. Because the...TURNING BEAM MIRRORS BEAM DISPLAYFOCUEED IRIS AT FOOS. OPTICAL FIBRE * BUNDLE Figure 49. Schematic of interferometer . -98-7 reflected speckle. The...As a check on the pulse simulation, the actual movement of an electron-beam foil window was measured by interferometry. A speckle interferometer which

  11. Preparation of graphene on Cu foils by ion implantation with negative carbon clusters

    NASA Astrophysics Data System (ADS)

    Li, Hui; Shang, Yan-Xia; Zhang, Zao-Di; Wang, Ze-Song; Zhang, Rui; Fu, De-Jun

    2015-01-01

    We report on few-layer graphene synthesized on Cu foils by ion implantation using negative carbon cluster ions, followed by annealing at 950 °C in vacuum. Raman spectroscopy reveals IG/I2D values varying from 1.55 to 2.38 depending on energy and dose of the cluster ions, indicating formation of multilayer graphene. The measurements show that the samples with more graphene layers have fewer defects. This is interpreted by graphene growth seeded by the first layers formed via outward diffusion of C from the Cu foil, though nonlinear damage and smoothing effects also play a role. Cluster ion implantation overcomes the solubility limit of carbon in Cu, providing a technique for multilayer graphene synthesis. Project supported by the National Natural Science Foundation of China (Grant Nos. 11105100, 11205116, and 11375135) and the State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, China (Grant No. AWJ-M13-03).

  12. Optical temperature sensing on flexible polymer foils

    NASA Astrophysics Data System (ADS)

    Sherman, Stanislav; Xiao, Yanfen; Hofmann, Meike; Schmidt, Thomas; Gleissner, Uwe; Zappe, Hans

    2016-04-01

    In contrast to established semiconductor waveguide-based or glass fiber-based integrated optical sensors, polymerbased optical systems offer tunable material properties, such as refractive index or viscosity, and thus provide additional degrees of freedom for sensor design and fabrication. Of particular interest in sensing applications are fully-integrated optical waveguide-based temperature sensors. These typically rely on Bragg gratings which induce a periodic refractive index variation in the waveguide so that a resonant wavelength of the structure is reflected.1,2 With broad-band excitation, a dip in the spectral output of the waveguide is thus generated at a precisely-defined wavelength. This resonant wavelength depends on the refractive index of the waveguide and the grating period, yet both of these quantities are temperature dependent by means of the thermo-optic effect (change in refractive index with temperature) and thermal expansion (change of the grating period with temperature). We show the design and fabrication of polymer waveguide-integrated temperature sensors based on Bragggratings, fabricated by replication technology on flexible PMMA foil substrates. The 175 μm thick foil serves as lower cladding for a polymeric waveguide fabricated from a custom-made UV-crosslinkable co-monomer composition. The fabrication of the grating structure includes a second replication step into a separate PMMA-foil. The dimensions of the Bragg-gratings are determined by simulations to set the bias point into the near infrared wavelength range, which allows Si-based detectors to be used. We present design considerations and performance data for the developed structures. The resulting sensor's signal is linear to temperature changes and shows a sensitivity of -306 nm/K, allowing high resolution temperature measurements.

  13. 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.

  14. 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.

  15. Thermal conductance of pressed metallic contacts augmented with Indium foil or Apiezon-N (tm) grease at liquid helium temperatures

    NASA Technical Reports Server (NTRS)

    Salerno, Louis J.; Kittel, Peter; Spivak, Alan L.

    1993-01-01

    The thermal conductance of pressed contacts which have been augmented with Indium foil or Apiezon-N (tm) grease was measured over the temperature range of 1.6 to 6.0 K, with applied forces from 22 N to 670 N. The sample pairs were fabricated from OFHC copper, 6061-T6 aluminum, free-machining brass, and 304 stainless steel. Although the thermal conductance was found to increase with increasing applied contact force, the force dependence was less than in earlier work. The addition of Indium foil or Apiezon-NT grease between the contact surfaces resulted in an improvement over uncoated surfaces ranging from a factor of approximately 3 for stainless steel to an order of magnitude for copper contacts.

  16. 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

  17. Radiation pressure acceleration of ultrathin foils

    NASA Astrophysics Data System (ADS)

    Macchi, Andrea; Veghini, Silvia; Liseykina, Tatyana V.; Pegoraro, Francesco

    2010-04-01

    The acceleration of sub-wavelength, solid-density plasma foils by the ultraintense radiation pressure of circularly polarized laser pulses is investigated analytically and with simulations. An improved 'Light Sail' or accelerating mirror model, accounting for nonlinear self-induced transparency effects, is used for estimating the optimal thickness for acceleration. The model predictions are in good agreement with one-dimensional simulations. These latter are analyzed in detail to unfold the dynamics and self-organization of electrons and ions during the acceleration. Two-dimensional simulations are also performed to address the effects of target bending and of laser intensity inhomogeneity.

  18. Note: the influence of exploding foil shape on energy deposition.

    PubMed

    Zeng, Qingxuan; Lv, Junjun; Li, Mingyu

    2013-06-01

    The main influence factors of exploding bridge foil were studied in order to improve energy utilization of the explosion foil initiator. "Square" and "curving" shaped bridge foils were fabricated using magnetron sputtering and chemical etching techniques, and the key dimension of the bridge foil was measured using surface profiler. Commercial software MATLAB was employed to calculate the burst current, burst voltage, and energy deposition. Simulation results were in good agreement with experiment data. In this study, the energy deposition ratio of "square" shaped bridge is between 45%-50%, while the value of "curving" shaped bridge is between 55%-75%.

  19. Characterization of U-Mo Foils for AFIP-7

    SciTech Connect

    Edwards, Danny J.; Ermi, Ruby M.; Schemer-Kohrn, Alan L.; Overman, Nicole R.; Henager, Charles H.; Burkes, Douglas; Senor, David J.

    2012-11-07

    Twelve AFIP in-process foil samples, fabricated by either Y-12 or LANL, were shipped from LANL to PNNL for potential characterization using optical and scanning electron microscopy techniques. Of these twelve, nine different conditions were examined to one degree or another using both techniques. For this report a complete description of the results are provided for one archive foil from each source of material, and one unirradiated piece of a foil of each source that was irradiated in the Advanced Test Reactor. Additional data from two other LANL conditions are summarized in very brief form in an appendix. The characterization revealed that all four characterized conditions contained a cold worked microstructure to different degrees. The Y-12 foils exhibited a higher degree of cold working compared to the LANL foils, as evidenced by the highly elongated and obscure U-Mo grain structure present in each foil. The longitudinal orientations for both of the Y-12 foils possesses a highly laminar appearance with such a distorted grain structure that it was very difficult to even offer a range of grain sizes. The U-Mo grain structure of the LANL foils, by comparison, consisted of a more easily discernible grain structure with a mix of equiaxed and elongated grains. Both materials have an inhomogenous grain structure in that all of the characterized foils possess abnormally coarse grains.

  20. Methods of making metallic glass foil laminate composites

    DOEpatents

    Vianco, P.T.; Fisher, R.W.; Hosking, F.M.; Zanner, F.J.

    1996-08-20

    A process for the fabrication of a rapidly solidified foil laminate composite. An amorphous metallic glass foil is flux treated and coated with solder. Before solidification of the solder the foil is collected on a take-up spool which forms the composite into a solid annular configuration. The resulting composite exhibits high strength, resiliency and favorable magnetic and electrical properties associated with amorphous materials. The composite also exhibits bonding strength between the foil layers which significantly exceeds the bulk strength of the solder alone. 6 figs.

  1. Producing titanium aluminide foil from plasma-sprayed preforms

    SciTech Connect

    Jha, S.C.; Forster, J.A. )

    1993-07-01

    A new method was used to fabricate foils of Ti-6Al-4V (Ti-6-4) alloy and Ti-14Al-21Nb(Ti-14-21) titanium aluminide, starting from a plasma-sprayed (PS) preform. The foils were 100 percent dense, with microstructures similar to those of wrought (IM) foil material. The foil made from PS preforms were characterized by the mechanical properties equivalent to their IM-processed counterparts. It is concluded that the method of roll consolidation of a PS preform is well suited for alloys and intermetallics that do not possess extensive hot and cold workability. 6 refs.

  2. SNS STRIPPER FOIL FAILURE MODES AND THEIR CURES

    SciTech Connect

    Galambos, John D; Luck, Chris; Plum, Michael A; Shaw, Robert W; Ladd, Peter; Raparia, Deepak; Macek, Robert James; Kim, Sang-Ho; Peters, Charles C; Polsky, Yarom

    2010-01-01

    The diamond stripper foils in use at the Spallation Neutron Source worked successfully with no failures until May 3, 2009, when we started experiencing a rash of foil system failures after increasing the beam power to ~840 kW. The main contributors to the failures are thought to be 1) convoy electrons, stripped from the incoming H beam, that strike the foil bracket and may also reflect back from the electron catcher, and 2) vacuum breakdown from the charge developed on the foil by secondary electron emission. In this paper we will detail these and other failure mechanisms, and describe the improvements we have made to mitigate them.

  3. Ti foil light in the ATA (Advanced Test Accelerator) beam

    SciTech Connect

    Slaughter, D.R.; Chong, Y.P.; Goosman, D.R.; Rule, D.W.; Fiorito, R.B.

    1987-09-01

    An experiment is in progress to characterize the visible light produced when a Ti foil is immersed in the ATA 2 kA, 43 MeV beam. Results obtained to date indicate that the optical condition of the foil surface is a critical determinant of these characteristics, with a very narrow angular distribution obtained when a highly polished and flat foil is used. These data are consistent with the present hypothesis that the light is produced by transition radiation. Incomplete experiments to determine the foil angle dependence of the detected light and its polarization are summarized and remaining experiments are described.

  4. Methods of making metallic glass foil laminate composites

    DOEpatents

    Vianco, Paul T.; Fisher, Robert W.; Hosking, Floyd M.; Zanner, Frank J.

    1996-01-01

    A process for the fabrication of a rapidly solidified foil laminate composite. An amorphous metallic glass foil is flux treated and coated with solder. Before solidification of the solder the foil is collected on a take-up spool which forms the composite into a solid annular configuration. The resulting composite exhibits high strength, resiliency and favorable magnetic and electrical properties associated with amorphous materials. The composite also exhibits bonding strength between the foil layers which significantly exceeds the bulk strength of the solder alone.

  5. Fabrication and evaluation of low fiber content alumina fiber/aluminum composites

    NASA Technical Reports Server (NTRS)

    Hack, J. E.; Strempek, G. C.

    1980-01-01

    The mechanical fabrication of low volume percent fiber, polycrystalline alumina fiber reinforced aluminum composites was accomplished. Wire preform material was prepared by liquid-metal infiltration of alumina fiber bundles. The wires were subsequently encapsulated with aluminum foil and fabricated into bulk composite material by hot-drawing. Extensive mechanical, thermal and chemical testing was conducted on preform and bulk material to develop a process and material data base. In addition, a preliminary investigation of mechanical forming of bulk alumina fiber reinforced aluminum composite material was conducted.

  6. Method of making porous conductive supports for electrodes. [by electroforming and stacking nickel foils

    NASA Technical Reports Server (NTRS)

    Schaer, G. R. (Inventor)

    1973-01-01

    Porous conductive supports for electrochemical cell electrodes are made by electroforming thin corrugated nickel foil, and by stacking pieces of the corrugated foil alternatively with pieces of thin flat nickel foil. Corrugations in successive corrugated pieces are oriented at different angles. Adjacent pieces of foil are bonded by heating in a hydrogen atmosphere and then cutting the stack in planes perpendicular to the foils.

  7. Development of full shell foil x-ray mirrors

    NASA Astrophysics Data System (ADS)

    Balsamo, Erin; Gendreau, Keith C.; Arzoumanian, Zaven; Jalota, Lalit; Kenyon, Steven J.; Fickau, David; Spartana, Nicholas; Hahne, Devin; Koenecke, Richard; Soong, Yang; Serlemitsos, Peter; Okajima, Takashi; Campion, Robert; Detweiler, Louis

    2012-09-01

    NICER will use full shell aluminum foil X-ray mirrors, similar to those that are currently being developed for the optics to be used for the XACT sounding rocket mission. Similar X-ray optics have been produced at Goddard Space Flight Center since the late 1970's. The mirror geometry used in the past and on some present missions consists of concentric quadrant shell mirrors with a conical approximation to the Wolter 1 geometry. For XACT, we are developing the next generation of these optics. Two innovations introduced in the mirrors are complete shells with a curve is in the reflectors' profile to produce a sharper focus than a conical approximation. X-ray imagers, such as those of Suzaku, ASCA, GEMS, and Astro-H require two reflections. Since XACT and NICER are using the optics as X-ray concentrators rather than full imaging optics, only one set of reflections is necessary. The largest shell in the NICER concentrator is 10cm diameter. Small diameter optics benefit from the rigidity of the full shell design. Also, the simplified support hardware reduced mass, which increases the effective area per unit mass. With 56 optics on NICER, each consisting of 24 full shell mirrors, an effective production process is needed for efficient manufacture of these mirrors. This production process is based on heritage techniques but modified for these new mirrors. This paper presents the production process of the innovative full shell optics and also results of optical and X-ray tests of the integrated optics.

  8. The feed-out process: Rayleigh-Taylor and Richtmyer-Meshkov instabilities in thin, laser-driven foils

    SciTech Connect

    Smitherman, D.P.

    1998-04-01

    Eight beams carrying a shaped pulse from the NOVA laser were focused into a hohlraum with a total energy of about 25 kJ. A planar foil was placed on the side of the hohlraum with perturbations facing away from the hohlraum. All perturbations were 4 {micro}m in amplitude and 50 {micro}m in wavelength. Three foils of pure aluminum were shot with thicknesses and pulse lengths respectively of 86 {micro}m and 2. 2 ns, 50 {micro}m and 4.5 ns, and 35 {micro}m with both 2.2 ns and 4. 5 ns pulses. Two composite foils constructed respectively of 32 and 84 {micro}m aluminum on the ablative side and 10 {micro}m beryllium on the cold surface were also shot using the 2.2 ns pulse. X-ray framing cameras recorded perturbation growth using both face- and side-on radiography. The LASNEX code was used to model the experiments. A shock wave interacted with the perturbation on the cold surface generating growth from a Richtmyer-Meshkov instability and a strong acoustic mode. The cold surface perturbation fed-out to the Rayleigh-Taylor unstable ablation surface, both by differential acceleration and interface coupling, where it grew. A density jump did not appear to have a large effect on feed-out from interface coupling. The Rayleigh-Taylor instability`s vortex pairs overtook and reversed the direction of flow of the Richtmyer-Meshkov vortices, resulting in the foil moving from a sinuous to a bubble and spike configuration. The Rayleigh-Taylor instability may have acted as an ablative instability on the hot surface, and as a classical instability on the cold surface, on which grew second and third order harmonics.

  9. Strain hardening in bent copper foils

    NASA Astrophysics Data System (ADS)

    Hayashi, Ichiro; Sato, Masumi; Kuroda, Mitsutoshi

    2011-09-01

    A series of systematic tensile and microbend tests were conducted on copper foil specimens with different thicknesses. The specimens were made of a copper foil having almost unidirectional crystal orientations that was considered to be nearly single-crystal. In order to investigate the effects of slip system interactions, two different crystal orientations relative to the tensile direction were considered in the tests: one is close to coplanar double-slip orientation, and the other is close to the ideal cube orientation (the tensile direction nearly coincides to [0 0 1]) that yields multi-planar multi-slip deformation. We extended the microbend test method to include the reversal of bending, and we attempted to divide the total amount of strain-hardening into isotropic and kinematic hardening components. In the tensile tests, no systematic tendency of size dependence was observed. In the microbend tests, size-dependent kinematic hardening behavior was observed for both the crystal orientations, while size dependence of isotropic hardening was observed only for the multi-planar multi-slip case. We introduce an extended crystal plasticity model that accounts for the effects of the geometrically necessary dislocations (GNDs), which correspond to the spatial gradients of crystallographic slips. Through numerical simulations performed using the model, the origin of the size-dependent behavior observed in the microbend tests is discussed.

  10. Quantitative NIR-Raman analysis of methyl-parathion pesticide microdroplets on aluminum substrates.

    PubMed

    Sato-Berrú, R Ysacc; Medina-Valtierra, Jorge; Medina-Gutiérrez, Cirilo; Frausto-Reyes, Claudio

    2004-08-01

    The potential of Raman spectroscopy in the quantitative analysis of dilute organic contaminants on aluminum substrates is evidenced in this work. Methyl-parathion microdroplets, an organophosphorus pesticide, has been used as a probe for this purpose. The samples were analyzed on an aluminum foil, which is very easy to acquire and to adapt. Moreover, aluminum foil does not need a previous treatment. Linear and no-linear curves as a function of the concentration of methyl-parathion versus the Raman intensity of the 1345 and 1110 cm(-1) peaks were established by means of a simple mathematical expression. A comparison with calibration curves fits very well, allowing quantification at concentration levels as low as parts per million.

  11. Actinide Foil Production for MPACT Research

    SciTech Connect

    Beller, Denis

    2012-10-30

    Sensitive fast-neutron detectors are required for use in lead slowing down spectrometry (LSDS), an active interrogation technique for used nuclear fuel assay for Materials Protection, Accounting, and Controls Technologies (MPACT). During the past several years UNLV sponsored a research project at RPI to investigate LSDS; began development of fission chamber detectors for use in LSDS experiments in collaboration with INL, LANL, and Oregon State U.; and participated in a LSDS experiment at LANL. In the LSDS technique, research has demonstrated that these fission chamber detectors must be sensitive to fission energy neutrons but insensitive to thermal-energy neutrons. Because most systems are highly sensitive to large thermal neutron populations due to the well-known large thermal cross section of 235U, even a miniscule amount of this isotope in a fission chamber will overwhelm the small population of higher-energy neutrons. Thus, fast-fission chamber detectors must be fabricated with highly depleted uranium (DU) or ultra-pure thorium (Th), which is about half as efficient as DU. Previous research conducted at RPI demonstrated that the required purity of DU for assay of used nuclear fuel using LSDS is less than 4 ppm 235U, material that until recently was not available in the U.S. In 2009 the PI purchased 3 grams of ultra-depleted uranium (uDU, 99.99998% 238U with just 0.2 ± 0.1 ppm 235U) from VNIIEF in Sarov, Russia. We received the material in the form of U3O8 powder in August of 2009, and verified its purity and depletion in a FY10 MPACT collaboration project. In addition, chemical processing for use in FC R&D was initiated, fission chamber detectors and a scanning alpha-particle spectrometer were developed, and foils were used in a preliminary LSDS experiment at a LANL/LANSCE in Sept. of 2010. The as-received U3O8 powder must be chemically processed to convert it to another chemical form while maintaining its purity, which then must be used to electro-deposit U

  12. Insulating effectiveness of self-spacing dimpled foil

    NASA Technical Reports Server (NTRS)

    Bond, J. A.

    1972-01-01

    Experimental data are graphed for determining conductive heat losses of multilayer insulation as function of number of foil layers. Foil was 0.0051 cm thick Nb, 1% Zr refractory alloy, dimpled to 0.0254 cm with approximately 28 dimples/sq cm. Heat losses were determined at 0.1 microtorr between 700 and 1089 K.

  13. Foil fabrication for the ROMANO event. Revision 1

    SciTech Connect

    Romo, J.G. Jr.; Weed, J.W.; Griggs, G.E.; Brown, T.G.; Tassano, P.L.

    1984-06-13

    The Vacuum Processes Lab (VPL), of LLNL's M.E. Dept. - Material Fabrication Division (MFD), conducted various vacuum related support activities for the ROMANO nuclear physics experiment. This report focuses on the foil fabrication activities carried out between July and November 1983 for the ROMANO event. Other vacuum related activities for ROMANO, such as outgassing tests of materials, are covered in separate documentation. VPL was asked to provide 270 coated Parylene foils for the ROMANO event. However, due to the developmental nature of some of the procedures, approximately 400 coated foils were processed. In addition, VPL interacted with MFD's Plastics Shop to help supply Parylene substrates to other organizations (i.e., LBL and commercial vendors) which had also been asked to provide coated foils for ROMANO. The purposes of this report are (A) to document the processes developed and the techniques used to produce the foils, and (B) to suggest future directions. The report is divided into four sections describing: (1) nuclear target foil fabrication, (2) Parylene substrate preparation and production, (3) calibration foil fabrication, and (4) foil and substrate inspections.

  14. Characterization of laser-cut copper foil X-pinches

    NASA Astrophysics Data System (ADS)

    Collins, G. W.; Valenzuela, J. C.; Hansen, S. B.; Wei, M. S.; Reed, C. T.; Forsman, A. C.; Beg, F. N.

    2016-10-01

    Quantitative data analyses of laser-cut Cu foil X-pinch experiments on the 150 ns quarter-period, ˜250 kA GenASIS driver are presented. Three different foil designs are tested to determine the effects of initial structure on pinch outcome. Foil X-pinch data are also presented alongside the results from wire X-pinches with comparable mass. The X-ray flux and temporal profile of the emission from foil X-pinches differed significantly from that of wire X-pinches, with all emission from the foil X-pinches confined to a ˜3 ns period as opposed to the delayed, long-lasting electron beam emission common in wire X-pinches. Spectroscopic data show K-shell as well as significant L-shell emission from both foil and wire X-pinches. Fits to synthetic spectra using the SCRAM code suggest that pinching foil X's produced a ˜1 keV, ne ≥ 1023 cm-3 plasma. The spectral data combined with the improved reliability of the source timing, flux, and location indicate that foil X-pinches generate a reproducible, K-shell point-projection radiography source that can be easily modified and tailored to suit backlighting needs across a variety of applications.

  15. Gas Foil Bearing Misalignment and Unbalance Effects

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.

    2008-01-01

    The effects of misalignment and unbalance on gas foil bearings are presented. The future of U.S. space exploration includes plans to conduct science missions aboard space vehicles, return humans to the Moon, and place humans on Mars. All of these endeavors are of long duration, and require high amounts of electrical power for propulsion, life support, mission operations, etc. One potential source of electrical power of sufficient magnitude and duration is a nuclear-fission-based system. The system architecture would consist of a nuclear reactor heat source with the resulting thermal energy converted to electrical energy through a dynamic power conversion and heat rejection system. Various types of power conversion systems can be utilized, but the Closed Brayton Cycle (CBC) turboalternator is one of the leading candidates. In the CBC, an inert gas heated by the reactor drives a turboalternator, rejects excess heat to space through a heat exchanger, and returns to the reactor in a closed loop configuration. The use of the CBC for space power and propulsion is described in more detail in the literature (Mason, 2003). In the CBC system just described, the process fluid is a high pressure inert gas such as argon, krypton, or a helium-xenon mixture. Due to the closed loop nature of the system and the associated potential for damage to components in the system, contamination of the working fluid is intolerable. Since a potential source of contamination is the lubricant used in conventional turbomachinery bearings, Gas Foil Bearings (GFB) have high potential for the rotor support system. GFBs are compliant, hydrodynamic journal and thrust bearings that use a gas, such as the CBC working fluid, as their lubricant. Thus, GFBs eliminate the possibility of contamination due to lubricant leaks into the closed loop system. Gas foil bearings are currently used in many commercial applications, both terrestrial and aerospace. Aircraft Air Cycle Machines (ACMs) and ground

  16. Tubular hydrogen permeable metal foil membrane and method of fabrication

    DOEpatents

    Paglieri, Stephen N.; Birdsell, Stephen A.; Barbero, Robert S.; Snow, Ronny C.; Smith, Frank M.

    2006-04-04

    A tubular hydrogen permeable metal membrane and fabrication process comprises obtaining a metal alloy foil having two surfaces, coating the surfaces with a metal or metal alloy catalytic layer to produce a hydrogen permeable metal membrane, sizing the membrane into a sheet with two long edges, wrapping the membrane around an elongated expandable rod with the two long edges aligned and overlapping to facilitate welding of the two together, placing the foil wrapped rod into a surrounding fixture housing with the two aligned and overlapping foil edges accessible through an elongated aperture in the surrounding fixture housing, expanding the elongated expandable rod within the surrounding fixture housing to tighten the foil about the expanded rod, welding the two long overlapping foil edges to one another generating a tubular membrane, and removing the tubular membrane from within the surrounding fixture housing and the expandable rod from with the tubular membrane.

  17. Foil Gas Thrust Bearings for High-Speed Turbomachinery

    NASA Technical Reports Server (NTRS)

    Edmonds, Brian; DellaCorte, Christopher; Dykas, Brian

    2010-01-01

    A methodology has been developed for the design and construction of simple foil thrust bearings intended for parametric performance testing and low marginal costs, supporting continued development of oil-free turbomachinery. A bearing backing plate is first machined and surface-ground to produce flat and parallel faces. Partial-arc slots needed to retain the foil components are then machined into the plate by wire electrical discharge machining. Slot thicknesses achievable by a single wire pass are appropriate to accommodate the practical range of foil thicknesses, leaving a small clearance in this hinged joint to permit limited motion. The backing plate is constructed from a nickel-based superalloy (Inconel 718) to allow heat treatment of the entire assembled bearing, as well as to permit hightemperature operation. However, other dimensionally stable materials, such as precipitation-hardened stainless steel, can also be used for this component depending on application. The top and bump foil blanks are cut from stacks of annealed Inconel X-750 foil by the same EDM process. The bump foil has several azimuthal slits separating it into five individual bump strips. This configuration allows for variable bump spacing, which helps to accommodate the effects of the varying surface velocity, thermal crowning, centrifugal dishing, and misalignment. Rectangular tabs on the foil blanks fit into the backing plate slots. For this application, a rather traditional set of conventionally machined dies is selected, and bump foil blanks are pressed into the dies for forming. This arrangement produces a set of bump foil dies for foil thrust bearings that provide for relatively inexpensive fabrication of various bump configurations, and employing methods and features from the public domain.

  18. Non-destructive Quantitative Phase Analysis and Microstructural Characterization of Zirconium Coated U-10Mo Fuel Foils via Neutron Diffraction

    SciTech Connect

    Cummins, Dustin Ray; Vogel, Sven C.; Hollis, Kendall Jon; Brown, Donald William; Dombrowski, David E.

    2016-10-18

    This report uses neutron diffraction to investigate the crystal phase composition of uranium-molybdenum alloy foils (U-10Mo) for the CONVERT MP-1 Reactor Conversion Project, and determines the effect on alpha-uranium contamination following the deposition of a Zr metal diffusion layer by various methods: plasma spray deposition of Zr powders at LANL and hot co-rolling with Zr foils at BWXT. In summary, there is minimal decomposition of the gamma phase U-10Mo foil to alpha phase contamination following both plasma spraying and hot co-rolling. The average unit cell volume, i.e. lattice spacing, of the Zr layer can be mathematically extracted from the diffraction data; co-rolled Zr matches well with literature values of bulk Zr, while plasma sprayed Zr shows a slight increase in the lattice spacing, indicative of interstitial oxygen in the lattice. Neutron diffraction is a beneficial alternative to conventional methods of phase composition, i.e. x ray diffraction (XRD) and destructive metallography. XRD has minimal penetration depth in high atomic number materials, particularly uranium, and can only probe the first few microns of the fuel plate; neutrons pass completely through the foil, allowing for bulk analysis of the foil composition and no issues with addition of cladding layers, as in the final, aluminum-clad reactor fuel plates. Destructive metallography requires skilled technicians, cutting of the foil into small sections, hazardous etching conditions, long polishing and microscopy times, etc.; the neutron diffraction system has an automated sample loader and can fit larger foils, so there is minimal analysis preparation; the total spectrum acquisition time is ~ 1 hour per sample. The neutron diffraction results are limited by spectra refinement/calculation times and the availability of the neutron beam source. In the case of LANSCE at Los Alamos, the beam operates ~50% of the year. Following the lessons learned from these preliminary results, optimizations to

  19. High strain rate metalworking with vaporizing foil actuator: control of flyer velocity by varying input energy and foil thickness.

    PubMed

    Vivek, A; Hansen, S R; Daehn, Glenn S

    2014-07-01

    Electrically driven rapid vaporization of thin metallic foils can generate a high pressure which can be used to launch flyers at high velocities. Recently, vaporizing foil actuators have been applied toward a variety of impulse-based metal working operations. In order to exercise control over this useful tool, it is imperative that an understanding of the effect of characteristics of the foil actuator on its ability for mechanical impulse generation is developed. Here, foil actuators made out of 0.0508 mm, 0.0762 mm, and 0.127 mm thick AA1145 were used for launching AA2024-T3 sheets of thickness 0.508 mm toward a photonic Doppler velocimeter probe. Launch velocities ranging between 300 m/s and 1100 m/s were observed. In situ measurement of velocity, current, and voltage assisted in understanding the effect of burst current density and deposited electrical energy on average pressure and velocity with foil actuators of various thicknesses. For the pulse generator, geometry, and flyer used here, the 0.0762 mm thick foil was found to be optimal for launching flyers to high velocities over short distances. Experimenting with annealed foil actuators resulted in no change in the temporal evolution of flyer velocity as compared to foil actuators of full hard temper. A physics-based analytical model was developed and found to have reasonable agreement with experiment.

  20. High strain rate metalworking with vaporizing foil actuator: Control of flyer velocity by varying input energy and foil thickness

    NASA Astrophysics Data System (ADS)

    Vivek, A.; Hansen, S. R.; Daehn, Glenn S.

    2014-07-01

    Electrically driven rapid vaporization of thin metallic foils can generate a high pressure which can be used to launch flyers at high velocities. Recently, vaporizing foil actuators have been applied toward a variety of impulse-based metal working operations. In order to exercise control over this useful tool, it is imperative that an understanding of the effect of characteristics of the foil actuator on its ability for mechanical impulse generation is developed. Here, foil actuators made out of 0.0508 mm, 0.0762 mm, and 0.127 mm thick AA1145 were used for launching AA2024-T3 sheets of thickness 0.508 mm toward a photonic Doppler velocimeter probe. Launch velocities ranging between 300 m/s and 1100 m/s were observed. In situ measurement of velocity, current, and voltage assisted in understanding the effect of burst current density and deposited electrical energy on average pressure and velocity with foil actuators of various thicknesses. For the pulse generator, geometry, and flyer used here, the 0.0762 mm thick foil was found to be optimal for launching flyers to high velocities over short distances. Experimenting with annealed foil actuators resulted in no change in the temporal evolution of flyer velocity as compared to foil actuators of full hard temper. A physics-based analytical model was developed and found to have reasonable agreement with experiment.

  1. High strain rate metalworking with vaporizing foil actuator: Control of flyer velocity by varying input energy and foil thickness

    SciTech Connect

    Vivek, A. Hansen, S. R.; Daehn, Glenn S.

    2014-07-15

    Electrically driven rapid vaporization of thin metallic foils can generate a high pressure which can be used to launch flyers at high velocities. Recently, vaporizing foil actuators have been applied toward a variety of impulse-based metal working operations. In order to exercise control over this useful tool, it is imperative that an understanding of the effect of characteristics of the foil actuator on its ability for mechanical impulse generation is developed. Here, foil actuators made out of 0.0508 mm, 0.0762 mm, and 0.127 mm thick AA1145 were used for launching AA2024-T3 sheets of thickness 0.508 mm toward a photonic Doppler velocimeter probe. Launch velocities ranging between 300 m/s and 1100 m/s were observed. In situ measurement of velocity, current, and voltage assisted in understanding the effect of burst current density and deposited electrical energy on average pressure and velocity with foil actuators of various thicknesses. For the pulse generator, geometry, and flyer used here, the 0.0762 mm thick foil was found to be optimal for launching flyers to high velocities over short distances. Experimenting with annealed foil actuators resulted in no change in the temporal evolution of flyer velocity as compared to foil actuators of full hard temper. A physics-based analytical model was developed and found to have reasonable agreement with experiment.

  2. Microstructure Evolution and Composition Control During the Processing of Thin-Gage Metallic Foil

    NASA Astrophysics Data System (ADS)

    Semiatin, S. L.; Gross, M. E.; Matson, D. W.; Bennett, W. D.; Bonham, C. C.; Ustinov, A. I.; Ballard, D. L.

    2012-12-01

    The manufacture of thin-gage superalloy and gamma-titanium-aluminide foil products via near-conventional thermomechanical processing and two different vapor-deposition methods was investigated. Thermomechanical processing was based on hot-pack rolling of plate and sheet. Foils of the superalloy LSHR and the near-gamma titanium aluminide Ti-45.5Al-2Cr-2Nb made by this approach exhibited excellent gage control and fine two-phase microstructures. The vapor-phase techniques used magnetron sputtering (MS) of a target of the desired product composition or electron-beam physical vapor deposition (EBPVD) of separate targets of the specific alloying elements. Thin deposits of LSHR and Ti-48Al-2Cr-2Nb made by MS showed uniform thickness/composition and an ultrafine microstructure. However, systematic deviations from the specific target composition were found. During subsequent heat treatment, the microstructure of the MS samples showed various degrees of grain growth and coarsening. Foils of Ti-43Al and Ti-51Al-1V fabricated by EBPVD were fully dense. The microstructures developed during EBPVD were interpreted in terms of measured phase equilibria and the dependence of evaporant flux on temperature.

  3. Interpreting Idioms.

    ERIC Educational Resources Information Center

    Kemper, Susan; Estill, Robert

    A study investigated the immediate comprehension processes involved in the interpretation of English idiomatic expressions. Idioms such as "bury the hatchet" were presented to 48 college students in sentential contexts that either biased the subject toward a literal or a figurative interpretation or left the interpretation ambiguous. In control…

  4. Modification of base-side {sup 99}MO production processes for LEU metal-foil targets.

    SciTech Connect

    Vandegrift, G. F.; Leonard, R. A.; Aase, S.; Sedlet, J.; Koma, Y.; Conner, C.; Clark, C. R.; Meyer, M. K.

    1999-09-30

    Argonne National Laboratory is cooperating with the National Atomic Energy Commission of the Argentine Republic (CNEA) to convert their {sup 99}Mo production process, which uses high enriched uranium (HEU), to low-enriched uranium (LEU), The program is multifaceted; however, discussed in this paper are (1) results of laboratory experiments to develop means for substituting LEU metal-foil targets into the current process and (2) preparation of uranium-alloy or uranium-metal/aluminum-dispersion targets. Although {sup 99}Mo production is a multi-step process, the first two steps (target dissolution and primary molybdenum recovery) are by far the most important in the conversion. Commonly, once molybdenum is separated from the bulk of the uranium, the remainder of the process need not be modified. Our results show that up to this point in our study, conversion of the CNEA process to LEU appears viable.

  5. Foil X-Ray Mirrors for Astronomical Observations: Still an Evolving Technology

    NASA Technical Reports Server (NTRS)

    Serlemitsos, Peter J.; Soong, Yang; Okajima, Takashi; Hahne, Devin J.

    2011-01-01

    Foil X-ray mirrors, introduced by the Goddard X-ray Group in the late 1970s, were envisioned as an interim and complementary approach toward increased sensitivity for small inexpensive astronomical instruments. The extreme light weight nature of these mirrors dovetailed beautifully with Japan's small payload missions, leading to several collaborative, earth orbiting observatories, designed primarily for spectroscopy, of which SUZAKU is still in earth orbit. ASTRO-H is the latest joint instrument with Japan, presently in the implementation phase. At Goddard, some 30 years after we introduced them, we are involved with four separate flight instruments utilizing foil X-ray mirrors, a good indication that this technology is here to stay. Nevertheless, an improved spatial resolution will be the most welcomed development by all. The task of preparing upwards of 1000 reflectors, then assembling them into a single mirror with arcmin resolution remains a formidable one. Many, performance limiting approximations become necessary when converting commercial aluminum sheets into 8 quadrant segments, each with approximately 200 nested conical, approximately 4Angstrom surface reflectors, which are then assembled into a single mirror. In this paper we will describe the mirror we are presently involved with, slated for the Goddard high resolution imaging X-ray spectrometer (SXS) onboard ASTRO-H. Improved spatial resolution will be an important enhancement to the science objectives from this instrument. We are accordingly pursuing and will briefly describe in this paper several design and reflector assembly modifications, aimed toward that goal.

  6. Corrosion of aluminum and aluminum alloys

    SciTech Connect

    Davis, J.R.

    1999-01-01

    This new handbook presents comprehensive coverage of the corrosion behavior of aluminum and aluminum alloys, with emphasis on practical information about how to select and process these materials in order to prevent corrosion attack. Described are the characteristics of these materials and the influences of composition, mechanical working, heat treatment, joining methods, microstructure, and environmental variables on their corrosion.

  7. ALUMINUM-CONTAINING POLYMERS

    DTIC Science & Technology

    ALUMINUM COMPOUNDS, *ORGANOMETALLIC COMPOUNDS, *POLYMERIZATION, *POLYMERS, ACRYLIC RESINS, ALKYL RADICALS, CARBOXYLIC ACIDS, COPOLYMERIZATION, LIGHT TRANSMISSION, STABILITY, STYRENES, TRANSPARENT PANELS.

  8. Producing Foils From Direct Cast Titanium Alloy Strip

    NASA Technical Reports Server (NTRS)

    Stuart, T. A.; Gaspar, T. A.; Sukonnik, I. M.; Semiatan, S. L.; Batawi, E.; Peters, J. A.; Fraser, H. L.

    1996-01-01

    This research was undertaken to demonstrate the feasibility of producing high-quality, thin-gage, titanium foil from direct cast titanium strip. Melt Overflow Rapid Solidification Technology (MORST) was used to cast several different titanium alloys into 500 microns thick strip, 10 cm wide and up to 3 m long. The strip was then either ground, hot pack rolled or cold rolled, as appropriate, into foil. Gamma titanium aluminide (TiAl) was cast and ground to approximately 100 microns thick foil and alpha-2 titanium aluminide (Ti3AI) was cast and hot pack rolled to approximately 70 microns thick foil. CP Ti, Ti6Al2Sn4Zr2Mo, and Ti22AI23Nb (Orthorhombic), were successfully cast and cold-rolled into good quality foil (less than 125 microns thick). The foils were generally fully dense with smooth surfaces, had fine, uniform microstructures, and demonstrated mechanical properties equivalent to conventionally produced titanium. By eliminating many manufacturing steps, this technology has the potential to produce thin gage, titanium foil with good engineering properties at significantly reduced cost relative to conventional ingot metallurgy processing.

  9. Compliant Foil Journal Bearing Performance at Alternate Pressures and Temperatures

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert J.; Puleo, Bernadette J.

    2008-01-01

    An experimental test program has been conducted to determine the highly loaded performance of current generation gas foil bearings at alternate pressures and temperatures. Typically foil bearing performance has been reported at temperatures relevant to turbomachinery applications but only at an ambient pressure of one atmosphere. This dearth of data at alternate pressures has motivated the current test program. Two facilities were used in the test program, the ambient pressure rig and the high pressure rig. The test program utilized a 35 mm diameter by 27 mm long foil journal bearing having an uncoated Inconel X-750 top foil running against a shaft with a PS304 coated journal. Load capacity tests were conducted at 3, 6, 9, 12, 15, 18, and 21 krpm at temperatures from 25 to 500 C and at pressures from 0.1 to 2.5 atmospheres. Results show an increase in load capacity with increased ambient pressure and a reduction in load capacity with increased ambient temperature. Below one-half atmosphere of ambient pressure a dramatic loss of load capacity is experienced. Additional lightly loaded foil bearing performance in nitrogen at 25 C and up to 48 atmospheres of ambient pressure has also been reported. In the lightly loaded region of operation the power loss increases for increasing pressure at a fixed load. Knowledge of foil bearing performance at operating conditions found within potential machine applications will reduce program development risk of future foil bearing supported turbomachines.

  10. Aluminum reference electrode

    DOEpatents

    Sadoway, D.R.

    1988-08-16

    A stable reference electrode is described for use in monitoring and controlling the process of electrolytic reduction of a metal. In the case of Hall cell reduction of aluminum, the reference electrode comprises a pool of molten aluminum and a solution of molten cryolite, Na[sub 3]AlF[sub 6], wherein the electrical connection to the molten aluminum does not contact the highly corrosive molten salt solution. This is accomplished by altering the density of either the aluminum (decreasing the density) or the electrolyte (increasing the density) so that the aluminum floats on top of the molten salt solution. 1 fig.

  11. Aluminum reference electrode

    DOEpatents

    Sadoway, Donald R.

    1988-01-01

    A stable reference electrode for use in monitoring and controlling the process of electrolytic reduction of a metal. In the case of Hall cell reduction of aluminum, the reference electrode comprises a pool of molten aluminum and a solution of molten cryolite, Na.sub.3 AlF.sub.6, wherein the electrical connection to the molten aluminum does not contact the highly corrosive molten salt solution. This is accomplished by altering the density of either the aluminum (decreasing the density) or the electrolyte (increasing the density) so that the aluminum floats on top of the molten salt solution.

  12. A novel carbon coating technique for foil bolometers.

    PubMed

    Sheikh, U A; Duval, B P; Labit, B; Nespoli, F

    2016-11-01

    Naked foil bolometers can reflect a significant fraction of incident energy and therefore cannot be used for absolute measurements. This paper outlines a novel coating approach to address this problem by blackening the surface of gold foil bolometers using physical vapour deposition. An experimental bolometer was built containing four standard gold foil bolometers, of which two were coated with 100+ nm of carbon. All bolometers were collimated and observed the same relatively high temperature, ohmically heated plasma. Preliminary results showed 13%-15% more incident power was measured by the coated bolometers and this is expected to be much higher in future TCV detached divertor experiments.

  13. Mechanical properties of micro- and nanocrystalline diamond foils

    PubMed Central

    Lodes, M. A.; Kachold, F. S.; Rosiwal, S. M.

    2015-01-01

    Diamond coating of suitable template materials and subsequent delamination allows for the manufacturing of free-standing diamond foil. The evolution of the microstructure can be influenced by secondary nucleation via control of process conditions in the hot-filament chemical vapour deposition process. Bending tests show extraordinarily high strength (more than 8 GPa), especially for diamond foils with nanocrystalline structure. A detailed fractographic analysis is conducted in order to correlate measured strength values with crack-initiating defects. The size of the failure causing flaw can vary from tens of micrometres to tens of nanometres, depending on the diamond foil microstructure as well as the loading conditions. PMID:25713455

  14. Functional multi-band THz meta-foils

    PubMed Central

    Wu, Jianfeng; Moser, Herbert O.; Xu, Su; Jian, Linke; Banas, Agnieszka; Banas, Krzysztof; Chen, Hongsheng; Bettiol, Andrew A.; Breese, Mark B. H.

    2013-01-01

    In this paper, we present the first experimental demonstration of double- and triple-band negative refraction index meta-foils in the terahertz (THz) region. Multi-band meta-foils constructed by multi-cell S-string resonators in a single structure exhibit simultaneously negative permittivity and negative permeability responses at multiple frequencies. The phenomena are confirmed by numerical simulations and Fourier transform infrared spectroscopy measurements. The flexible, freestanding multi-band meta-foils provide a promising candidate for the development of multi-frequency THz materials and devices. PMID:24346309

  15. On the performance of hybrid foil-magnetic bearings

    SciTech Connect

    Heshmat, H.; Chen, H.M.; Walton, J.F. II.

    2000-01-01

    Recent technological advancements make hybridization of the magnetic and foil bearing both possible and extremely attractive. Operation of the foil/magnetic bearings takes advantage of the strengths of each individual bearing while minimizing each others weaknesses. In this paper one possible hybrid foil and magnetic bearing arrangement is investigated and sample design and operating parameters are presented. One of the weaknesses of the foil bearings, like any hydrodynamic bearing, is that contact between the foil bearing and the shaft occurs at rest or at very low speeds and it has low load carrying capacity at low speed. For high speed applications, AMBs are, however, vulnerable to rotor-bending or structural resonances that can easily saturate power amplifiers and make the control system unstable. Since the foil bearing is advantageous for high speed operation with a higher load carrying capacity, and the magnetic bearing is so in low speed range, it is a natural evolution to combine them into a hybrid bearing system thus utilizing the advantages of both. To take full advantage of the foil and magnetic elements comprising a hybrid bearing, it is imperative that the static and dynamic characteristics of each bearing be understood. This paper describes the development of a new analysis technique that was used to evaluate the performance of a class of gas-lubricated journal bearing. Unlike conventional approaches, the solution of the governing hydrodynamic equations dealing with compressible fluid is coupled with the structural resiliency of the bearing surface. The distribution of the fluid film thickness and pressures, as well as the shear stresses in a finite-width journal bearing, are computed. Using the Finite Element (FE) method, the membrane effect of an elastic top foil was evaluated and included in the overall analytical procedure. Influence coefficients were generated to address the elasticity effects of combined top foil and elastic foundation on the

  16. Method for laser welding ultra-thin metal foils

    DOEpatents

    Pernicka, J.C.; Benson, D.K.; Tracy, C.E.

    1996-03-26

    A method for simultaneously cutting and welding ultra-thin foils having a thickness of less than 0.002 inches wherein two ultra-thin films are stacked and clamped together. A pulsed laser such as of the Neodymium: YAG type is provided and the beam of the laser is directed onto the stacked films to cut a channel through the films. The laser is moved relative to the stacked foils to cut the stacked foils at successive locations and to form a plurality of connected weld beads to form a continuous weld. 5 figs.

  17. Method for laser welding ultra-thin metal foils

    DOEpatents

    Pernicka, John C.; Benson, David K.; Tracy, C. Edwin

    1996-01-01

    A method for simultaneously cutting and welding ultra-thin foils having a thickness of less than 0.002 inches wherein two ultra-thin films are stacked and clamped together. A pulsed laser such as of the Neodymium: YAG type is provided and the beam of the laser is directed onto the stacked films to cut a channel through the films. The laser is moved relative to the stacked foils to cut the stacked foils at successive locations and to form a plurality of connected weld beads to form a continuous weld.

  18. Elevated Temperature Tensile Tests on DU–10Mo Rolled Foils

    SciTech Connect

    Schulthess, Jason

    2014-09-01

    Tensile mechanical properties for uranium-10 wt.% molybdenum (U–10Mo) foils are required to support modeling and qualification of new monolithic fuel plate designs. It is expected that depleted uranium-10 wt% Mo (DU–10Mo) mechanical behavior is representative of the low enriched U–10Mo to be used in the actual fuel plates, therefore DU-10Mo was studied to simplify material processing, handling, and testing requirements. In this report, tensile testing of DU-10Mo fuel foils prepared using four different thermomechanical processing treatments were conducted to assess the impact of foil fabrication history on resultant tensile properties.

  19. Method of fabricating a uranium-bearing foil

    DOEpatents

    Gooch, Jackie G [Seymour, TN; DeMint, Amy L [Kingston, TN

    2012-04-24

    Methods of fabricating a uranium-bearing foil are described. The foil may be substantially pure uranium, or may be a uranium alloy such as a uranium-molybdenum alloy. The method typically includes a series of hot rolling operations on a cast plate material to form a thin sheet. These hot rolling operations are typically performed using a process where each pass reduces the thickness of the plate by a substantially constant percentage. The sheet is typically then annealed and then cooled. The process typically concludes with a series of cold rolling passes where each pass reduces the thickness of the plate by a substantially constant thickness amount to form the foil.

  20. A novel carbon coating technique for foil bolometers

    NASA Astrophysics Data System (ADS)

    Sheikh, U. A.; Duval, B. P.; Labit, B.; Nespoli, F.

    2016-11-01

    Naked foil bolometers can reflect a significant fraction of incident energy and therefore cannot be used for absolute measurements. This paper outlines a novel coating approach to address this problem by blackening the surface of gold foil bolometers using physical vapour deposition. An experimental bolometer was built containing four standard gold foil bolometers, of which two were coated with 100+ nm of carbon. All bolometers were collimated and observed the same relatively high temperature, ohmically heated plasma. Preliminary results showed 13%-15% more incident power was measured by the coated bolometers and this is expected to be much higher in future TCV detached divertor experiments.

  1. Neutron Field Measurements in Phantom with Foil Activation Methods.

    DTIC Science & Technology

    1986-11-29

    jI25 Ii III uumu ullli~ S....- - Lb - w * .qJ’ AD-A 192 122 ulJ. IL (pj DNA-TR-87- 10 N EUTRON FIELD MEASUREMENTS IN PHANTOM WITH FOIL ACTIVATION...SAND II Measurements in Phantom 6 4 The 5-Foil Neutron Dosimetry Method 29 5 Comparison of SAND II and Simple 5-Foil Dosimetry Method 34 6 Thermal ...quite reasonable. The monkey phantom spectrum differs from the NBS U-235 fission spectrum in that the former has a I/E tail plus thermal -neutron peak

  2. The “accumulation effect” of positrons in the stack of foils, detected by measurements of the positron implantation profile

    SciTech Connect

    Dryzek, Jerzy; Siemek, Krzysztof

    2013-12-14

    The profiles of positrons implanted from the radioactive source {sup 22}Na into a stack of foils and plates are the subject of our experimental and theoretical studies. The measurements were performed using the depth scanning of positron implantation profile method, and the theoretical calculations using the phenomenological multi-scattering model (MSM). Several stacks consisting of silver, gold and aluminum foils, and titanium and germanium plates were investigated. We notice that the MSM describes well the experimental profiles; however when the stack consisting of silver and gold foils, the backscattering and linear absorption coefficients differ significantly from those reported in the literature. We suggest the energy dependency of the backscattering coefficient for silver and gold. In the stacks which comprise titanium and germanium plates, there were observed the features, which indicate the presence of the “accumulation effect” in the experimental implantation profile. This effect was previously detected in implantation profiles in Monte Carlo simulations using the GEANT4 tool kit, and it consists in higher localization of positrons close the interface. We suppose that this effect can be essential for positron annihilation in any heterogeneous materials.

  3. Synchronization and Phase Dynamics of Oscillating Foils

    NASA Astrophysics Data System (ADS)

    Finkel, Cyndee L.

    In this work, a two-dimensional model representing the vortices that animals produce, when they are ying/swimming, was constructed. A D{shaped cylinder and an oscillating airfoil were used to mimic these body{shed and wing{generated vortices, respectively. The parameters chosen are based on the Reynolds numbers similar to that which is observed in nature (˜10 4). In order to imitate the motion of ying/swimming, the entire system was suspended into a water channel from frictionless air{bearings. The position of the apparatus in the channel was regulated with a linear, closed loop PI controller. Thrust/drag forces were measured with strain gauges and particle image velocimetry (PIV) was used to examine the wake structure that develops. The Strouhal number of the oscillating airfoil was compared to the values observed in nature as the system transitions between the accelerated and steady states. The results suggest that self-regulation restricts the values of the Strouhal number to a certain range where no other external sensory input is necessary. As suggested by previous work, this self-regulation is a result of a limit cycle process that stems from nonlinear periodic oscillations. The limit cycles were used to examine the synchronous conditions due to the coupling of the foil and wake vortices. Noise is a factor that can mask details of the synchronization. In order to control its effect, we study the locking conditions using an analytic technique that only considers the phases. Our results show that the phase locking indices are dependent on the Strouhal value as it converges to a frequency locking ratio of ≃0:5. This indicates that synchronization occurs during cruising between the motion of the foil and the measured thrust/drag response of the uid forces. The results suggest that Strouhal number selection in steady forward natural swimming and ying is the result of a limit cycle process and not actively controlled by an organism. An implication of this is

  4. Characterization of Electrodeposited Technetium on Gold Foil

    SciTech Connect

    Mausolf, Edward; Poineau, Frederic; Hartmann, Thomas; Droessler, Janelle; Czerwinski, Ken

    2011-11-17

    The reduction and electrodeposition of TcO{sub 4}{sup -} on a smooth gold foil electrode with an exposed area of 0.25 cm{sup 2} was performed in 1 M H{sub 2}SO{sub 4} supporting electrolyte using bulk electrolysis with a constant current density of 1.0 A/cm{sup 2} at a potential of -2.0 V. Significant hydrogen evolution accompanied the formation of Tc deposits. Tc concentrations consisted of 0.01 M and 2 x 10{sup -3} M and were electrodeposited over various times. Deposited fractions of Tc were characterized by powder x-ray diffraction, x-ray absorption fine structure spectroscopy, and scanning electron microscopy with the capability to measure semiquantitative elemental compositions by energy-dispersive x-ray emission spectroscopy. Results indicate the presence of Tc metal on all samples as the primary electrodeposited constituent for all deposition times and Tc concentrations. Thin films of Tc have been observed followed by the formation of beads that are removable by scratching. After 2000, the quantity of Tc removed from solution and deposited was 0.64 mg Tc per cm{sup 2}. The solution, after electrodeposition, showed characteristic absorbances near 500 nm corresponding to hydrolyzed Tc(IV) produced during deposition of Tc metal. No detectable Tc(IV) was deposited to the cathode.

  5. Stratification in Al and Cu foils exploded in vacuum

    SciTech Connect

    Baksht, R. B.; Rousskikh, A. G.; Zhigalin, A. S.; Artyomov, A. P.; Oreshkin, V. I.

    2015-10-15

    An experiment with exploding foils was carried out at a current density of 0.7 × 10{sup 8} A/cm{sup 2} through the foil with a current density rise rate of about 10{sup 15} A/cm{sup 2} s. To record the strata arising during the foil explosions, a two-frame radiographic system was used that allowed tracing the dynamics of strata formation within one shot. The original striation wavelength was 20–26 μm. It was observed that as the energy deposition to a foil stopped, the striation wavelength increased at a rate of ∼(5–9) × 10{sup 3} cm/s. It is supposed that the most probable reason for the stratification is the thermal instability that develops due to an increase in the resistivity of the metal with temperature.

  6. Moderation and diffusion of positrons in tungsten meshes and foils

    NASA Astrophysics Data System (ADS)

    Williams, A. I.; Murtagh, D. J.; Fayer, S. E.; Andersen, S. L.; Chevallier, J.; Kövér, Á.; Van Reeth, P.; Humberston, J. W.; Laricchia, G.

    2015-09-01

    The efficiency of tungsten meshes and thin foils for moderation of fast positrons from 22Na has been investigated in transmission geometry and a fair agreement has been found with previous experimental results where directly comparable. For foils, the dependence on material thickness is found to be similar to the prediction of the Vehanen-Mäkinen diffusion model; however, the magnitude is 5-10 times lower. A broad consensus is observed between experiment and the results of a three-dimensional model developed in this work. For a given thickness, meshes are found to be generally better than foils by around a factor of 10 with a maximum efficiency ( ˜10-3) comparable to that achieved with thin single crystal foils, in accord with previous measurements and the results of the present model.

  7. 21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Tin-coated lead foil capsules for wine bottles... lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one... covering applied over the cork and neck areas) on wine bottles to prevent insect infestation, as a...

  8. 21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Tin-coated lead foil capsules for wine bottles... lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one... covering applied over the cork and neck areas) on wine bottles to prevent insect infestation, as a...

  9. 21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tin-coated lead foil capsules for wine bottles. 189... lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one... covering applied over the cork and neck areas) on wine bottles to prevent insect infestation, as a...

  10. 21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Tin-coated lead foil capsules for wine bottles... lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one... covering applied over the cork and neck areas) on wine bottles to prevent insect infestation, as a...

  11. Aluminum: Recycling of Aluminum Dross/Saltcake

    SciTech Connect

    Blazek, S.

    1999-01-29

    As this NICE3 publication details, the objective of this project is to commercialize the process technology to eliminate all landfill waste associated with black dross and saltcake generated from aluminum recycling in the United States.

  12. A Novel Thermal Management Approach for Radial Foil Air Bearings

    DTIC Science & Technology

    2010-07-01

    Rossum (1). Since their discovery, foil bearings have been commonly used as rotor supports in air cycle machines (ACM’s) that are part of an...engines (6, 7). With air as the lubricant, foil bearings can successfully support high speed rotors in extreme temperature environments without the...low enough, can lead to rotor instability. On the other hand, a heavier preload will create higher start-up torque and lift-off speed requirements

  13. Evidence of muonium formation using thin gold foils in vacuum

    NASA Technical Reports Server (NTRS)

    Barnett, B. A.; Chang, C. Y.; Steinberg, P.; Yodh, G. B.; Orr, H. D.; Carroll, J. B.; Eckhause, M.; Kane, J. R.; Spence, C. B.; Hsieh, C. S.

    1977-01-01

    The production of thermal muonium in a vacuum region has been investigated using an array of 200 thin (about 1000 A thick) gold foils exposed to a stopping positive-muon beam. By examining the observed time dependence of the positive-muon decay spectra in various transverse magnetic field, it is estimated that the lower limit of the probability of muonium formation by these gold foils placed in vacuum was 0.28 plus or minus 0.05.

  14. A new low-melting-point aluminum braze

    SciTech Connect

    Jacobson, D.M.; Humpston, G.; Sangha, S.P.S.

    1996-08-01

    Most high-strength aluminum engineering alloys cannot be joined by brazing because they either degrade or melt at the temperature at which commercially available aluminum brazes are used. Previous efforts to develop aluminum brazing filler metal alloys with a significantly reduced melting point have tended to be frustrated by poor mechanical properties of the alloys, corrosion of the joints or the high cost, toxicity or volatility of the constituent materials. This paper describes the development and assessment of a new brazing alloy with a composition of 73Al-20Cu-2Ni-55I (wt-%), which has been designed to overcome these limitations. A joining process has been devised for fluxless brazing of aluminum engineering alloys using the new filler metal for use in both inert gas and vacuum furnaces. The production of ductile foil preforms and roll-clad base metals is described together with preliminary results of mechanical property assessments and corrosion resistance trials. These results are highly encouraging and point to promising new applications for aluminum brazing technology.

  15. Aluminum-Enhanced Underwater Electrical Discharges for Steam Explosion Triggering

    SciTech Connect

    HOGELAND, STEVE R.; NELSON, LLOYD S.; ROTH, THOMAS CHRISTOPHER

    1999-07-01

    For a number of years, we have been initiating steam explosions of single drops of molten materials with pressure and flow (bubble growth) transients generated by discharging a capacitor bank through gold bridgewires placed underwater. Recent experimental and theoretical advances in the field of steam explosions, however, have made it important to substantially increase these relatively mild transients in water without using high explosives, if possible. To do this with the same capacitor bank, we have discharged similar energies through tiny strips of aluminum foil submerged in water. By replacing the gold wires with the aluminum strips, we were able to add the energy of the aluminum-water combustion to that normally deposited electrically by the bridgewire explosion in water. The chemical enhancement of the explosive characteristics of the discharges was substantial: when the same electrical energies were discharged through the aluminum strips, peak pressures increased as much as 12-fold and maximum bubble volumes as much as 5-fold above those generated with the gold wires. For given weights of aluminum, the magnitudes of both parameters appeared to exceed those produced by the underwater explosion of equivalent weights of high explosives.

  16. FeN foils by nitrogen ion-implantation

    SciTech Connect

    Jiang, Yanfeng; Wang, Jian-Ping; Al Mehedi, Md; Fu, Engang; Wang, Yongqiang

    2014-05-07

    Iron nitride samples in foil shape (free standing, 500 nm in thickness) were prepared by a nitrogen ion-implantation method. To facilitate phase transformation, the samples were bonded on the substrate followed by a post-annealing step. By using two different substrates, single crystal Si and GaAs, structural and magnetic properties of iron nitride foil samples prepared with different nitrogen ion fluences were characterized. α″-Fe{sub 16}N{sub 2} phase in iron nitride foil samples was obtained and confirmed by the proposed approach. A hard magnetic property with coercivity up to 780 Oe was achieved for the FeN foil samples bonded on Si substrate. The feasibility of using nitrogen ion implantation techniques to prepare FeN foil samples up to 500 nm thickness with a stable martensitic phase under high ion fluences has been demonstrated. A possible mechanism was proposed to explain this result. This proposed method could potentially be an alternative route to prepare rare-earth-free FeN bulk magnets by stacking and pressing multiple free-standing thick α″-Fe{sub 16}N{sub 2} foils together.

  17. Induction Bonding of Prepreg Tape and Titanium Foil

    NASA Technical Reports Server (NTRS)

    Messier, Bernadette C.; Hinkley, Jeffrey A.; Johnston, Norman J.

    1998-01-01

    Hybrid structural laminates made of titanium foil and carbon fiber reinforced polymer composite offer a potential for improved performance in aircraft structural applications. To obtain information needed for the automated fabrication of hybrid laminates, a series of bench scale tests were conducted of the magnetic induction bonding of titanium foil and thermoplastic prepreg tape. Foil and prepreg specimens were placed in the gap of a toroid magnet mounted in a bench press. Several magnet power supplies were used to study power at levels from 0.5 to 1.75 kW and frequencies from 50 to 120 kHz. Sol-gel surface-treated titanium foil, 0.0125 cm thick, and PIXA/IM7 prepreg tape were used in several lay-up configurations. Data were obtained on wedge peel bond strength, heating rate, and temperature ramp over a range of magnet power levels and frequencies at different "power-on" times for several magnet gap dimensions. These data will be utilized in assessing the potential for automated processing. Peel strengths of foil-tape bonds depended on the maximum temperature reached during heating and on the applied pressure. Maximum peel strengths were achieved at 1.25kW and 8OkHz. Induction heating of the foil appears to be capable of good bonding up to 10 plies of tape. Heat transfer calculations indicate that a 20-40 C temperature difference exists across the tape thickness during heat-up.

  18. SU-E-T-151: Enhanced Radiation Attenuation with Multi-Layer Foils

    SciTech Connect

    Warmington, L; Watanabe, Y

    2014-06-01

    Purpose: To evaluate the effect of increasing the number of thin high Z foils on the dose enhancement and the overall radiation attenuation with a 24MV photon beam. Methods: DOSXYZnrc was used to perform Monte Carlo simulations of multi-layer lead foil configurations. The foil size was 7cm x 7cm. and the foil thickness was adjusted to give a combined thickness of 1mm. The number of foils used was 4, 6, 8, and 10. The separation between foils was also varied from 3 to 9 mm. The Mohan 24MV energy spectrum was used as a photon source. The field size was 5cm x 5cm and SSD was 100 cm. The phantom size was 16cm × 16cm × 28cm. The number of histories ranged from 1 to 2 billion. The percentage difference of the dose between the medium with foils and the homogeneous water was computed along the beam axis. The minimum dose enhancement and the change of integrated dose between the foils were determined. Results: Increasing the number of foils resulted in a decrease in the minimum dose enhancement. The highest dose region occurred in the last section for the 4 and 6 foil cases, whereas the 8 and 10 foil configurations showed the maximum dose region towards the center of the foil group. Increasing the number of foils increased the total integrated dose between foils. For example, the total integrated dose increase between the first and the last foils with a 3mm foil separation were 34.2, 43.4, 57.4, and 64.7% for 4, 6, 8 and 10 foils, respectively. Conclusion: This work showed the degree of dose enhancement around multiple thin lead foils. The results suggest that the total attenuation of photon beam can be increased by increasing the number of foils with a fixed total foil thickness.

  19. Aspects of aluminum toxicity

    SciTech Connect

    Hewitt, C.D.; Savory, J.; Wills, M.R. )

    1990-06-01

    Aluminum is the most abundant metal in the earth's crust. The widespread occurrence of aluminum, both in the environment and in foodstuffs, makes it virtually impossible for man to avoid exposure to this metal ion. Attention was first drawn to the potential role of aluminum as a toxic metal over 50 years ago, but was dismissed as a toxic agent as recently as 15 years ago. The accumulation of aluminum, in some patients with chronic renal failure, is associated with the development of toxic phenomena; dialysis encephalopathy, osteomalacic dialysis osteodystrophy, and an anemia. Aluminum accumulation also occurs in patients who are not on dialysis, predominantly infants and children with immature or impaired renal function. Aluminum has also been implicated as a toxic agent in the etiology of Alzheimer's disease, Guamiam amyotrophic lateral sclerosis, and parkinsonism-dementia. 119 references.

  20. Flame Tube and Ballistic Evaluation of Explosafe Aluminum Foil for Aircraft Fuel Tank Explosion Protection

    DTIC Science & Technology

    1980-04-01

    OIL FOR AIRCRAFT FUEL TANK EXPLOSION Aug• •77-MarI* ;P7 9 .OTECTI. 6 RFORMING ORG REPOT N BER •. j• H•. .J...Bob. Fiur 82 Scemtc iara f laeTue es qupmn Dra’i V3 56 .1 .~~~~~anfl Nock...... 7 2 7 . AFWAL-TR-80- 2031

  1. Role of Friction on the Thermal Development in Ultrasonically Consolidated Aluminum Foils and Composites

    DTIC Science & Technology

    2011-01-01

    Incropera and DeWitt’s (2001) introductory heat transfer textbook the Biot number is defined as: Bi = hl k (9) The Biot number is the ratio of...Thus, for Bi < 0.1 (thermally thin) Incropera and DeWitt (2001) state that a material’s internal temperature can usually be assumed to be spatially...New Jersey. Hodowany, J., 1997. On the conversion of plastic work into heat. California Institute of Technology. CaltechTHESIS, 118. Incropera , F.P

  2. Neutron Diffraction Measurement of Residual Stresses, Dislocation Density and Texture in Zr-bonded U-10Mo ''Mini'' Fuel Foils and Plates

    SciTech Connect

    Brown, Donald W.; Okuniewski, M. A.; Sisneros, Thomas A.; Clausen, Bjorn; Moore, G. A.; Balogh, L

    2014-08-07

    Aluminum clad monolithic uranium 10 weight percent molybdenum (U-10Mo) fuel plates are being considered for conversion of several research and test nuclear reactors from high-enriched to low-enriched uranium fuel due to the inherently high density of fissile material. Comprehensive neutron diffraction measurements of the evolution of the textures, residual phase stresses, and dislocation densities in the individual phases of the mini-foils throughout several processing steps and following hot-isostatic pressing to the Al cladding, have been completed. Recovery and recrystallization of the bare U-10Mo fuel foil, as indicated by the dislocation density and texture, are observed depending on the state of the material prior to annealing and the duration and temperature of the annealing process. In general, the HIP procedure significantly reduces the dislocation density, but the final state of the clad plate, both texture and dislocation density, depends strongly on the final processing step of the fuel foil. In contrast, the residual stresses in the clad fuel plate do not depend strongly on the final processing step of the bare foil prior to HIP bonding. Rather, the residual stresses are dominated by the thermal expansion mismatch of the constituent materials of the fuel plate.

  3. Fine Grain Aluminum Superplasticity

    DTIC Science & Technology

    1980-02-01

    time at elevated temperature for 7475 aluminum alloy 5 2 Optical micrographs of 7075 aluminum alloy after exposure to 5160C (960oF) for times...applied to Al-Zn-Mg-Cu ( 7075 Al) alloy. Subsequent developments by Waldman et al. (refs. 8-11) resulted in the demonstration that 7000 series alloys...a number of aluminum alloys. With such a fine grain structure, high temperature deformation character- istics approaching superplastic behavior

  4. BONDING ALUMINUM METALS

    DOEpatents

    Noland, R.A.; Walker, D.E.

    1961-06-13

    A process is given for bonding aluminum to aluminum. Silicon powder is applied to at least one of the two surfaces of the two elements to be bonded, the two elements are assembled and rubbed against each other at room temperature whereby any oxide film is ruptured by the silicon crystals in the interface; thereafter heat and pressure are applied whereby an aluminum-silicon alloy is formed, squeezed out from the interface together with any oxide film, and the elements are bonded.

  5. Aluminum powder metallurgy processing

    SciTech Connect

    Flumerfelt, J.F.

    1999-02-12

    The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from aluminum powder. The hypothesis was tested with pure aluminum powders produced by commercial air atomization, commercial inert gas atomization, and gas atomization reaction synthesis (GARS). A comparison of the GARS aluminum powders with the commercial aluminum powders showed the former to exhibit superior powder characteristics. The powders were compared in terms of size and shape, bulk chemistry, surface oxide chemistry and structure, and oxide film thickness. Minimum explosive concentration measurements assessed the dependence of explosibility hazard on surface area, oxide film thickness, and gas atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization oxidation of aluminum powder. An Al-Ti-Y GARS alloy exposed in ambient air at different temperatures revealed the effect of reactive alloy elements on post-atomization powder oxidation. The pure aluminum powders were consolidated by two different routes, a conventional consolidation process for fabricating aerospace components with aluminum powder and a proposed alternative. The consolidation procedures were compared by evaluating the consolidated microstructures and the corresponding mechanical properties. A low temperature solid state sintering experiment demonstrated that tap densified GARS aluminum powders can form sintering necks between contacting powder particles, unlike the total resistance to sintering of commercial air atomization aluminum powder.

  6. Performance of Simple Gas Foil Thrust Bearings in Air

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert J.

    2012-01-01

    Foil bearings are self-acting hydrodynamics devices used to support high speed rotating machinery. The advantages that they offer to process fluid lubricated machines include: high rotational speed capability, no auxiliary lubrication system, non-contacting high speed operation, and improved damping as compared to rigid hydrodynamic bearings. NASA has had a sporadic research program in this technology for almost 6 decades. Advances in the technology and understanding of foil journal bearings have enabled several new commercial products in recent years. These products include oil-free turbochargers for both heavy trucks and automobiles, high speed electric motors, microturbines for distributed power generation, and turbojet engines. However, the foil thrust bearing has not received a complimentary level of research and therefore has become the weak link of oil-free turbomachinery. In an effort to both provide machine designers with basic performance parameters and to elucidate the underlying physics of foil thrust bearings, NASA Glenn Research Center has completed an effort to experimentally measure the performance of simple gas foil thrust bearing in air. The database includes simple bump foil supported thrust bearings with full geometry and manufacturing techniques available to the user. Test conditions consist of air at ambient pressure and temperatures up to 500 C and rotational speeds to 55,000 rpm. A complete set of axial load, frictional torque, and rotational speed is presented for two different compliant sub-structures and inter-pad gaps. Data obtained from commercially available foil thrust bearings both with and without active cooling is presented for comparison. A significant observation made possible by this data set is the speed-load capacity characteristic of foil thrust bearings. Whereas for the foil journal bearing the load capacity increases linearly with rotational speed, the foil thrust bearing operates in the hydrodynamic high speed limit. In

  7. Nanoscale microstructure effects on hydrogen behavior in rapidly solidified aluminum alloys

    SciTech Connect

    Tashlykova-Bushkevich, Iya I.

    2015-12-31

    The present work summarizes recent progress in the investigation of nanoscale microstructure effects on hydrogen behavior in rapidly solidified aluminum alloys foils produced at exceptionally high cooling rates. We focus here on the potential of modification of hydrogen desorption kinetics in respect to weak and strong trapping sites that could serve as hydrogen sinks in Al materials. It is shown that it is important to elucidate the surface microstructure of the Al alloy foils at the submicrometer scale because rapidly solidified microstructural features affect hydrogen trapping at nanostructured defects. We discuss the profound influence of solute atoms on hydrogen−lattice defect interactions in the alloys. with emphasis on role of vacancies in hydrogen evolution; both rapidly solidified pure Al and conventionally processed aluminum samples are considered.

  8. Interpretive Experiments

    ERIC Educational Resources Information Center

    DeHaan, Frank, Ed.

    1977-01-01

    Describes an interpretative experiment involving the application of symmetry and temperature-dependent proton and fluorine nmr spectroscopy to the solution of structural and kinetic problems in coordination chemistry. (MLH)

  9. Interpreting Bones.

    ERIC Educational Resources Information Center

    Weymouth, Patricia P.

    1986-01-01

    Describes an activity which introduces students to the nature and challenges of paleoanthropology. In the exercise, students identify diagrammed bones and make interpretations about the creature. Presents questions and tasks employed in the lesson. (ML)

  10. A Microfabricated Involute-Foil Regenerator for Stirling Engines

    NASA Technical Reports Server (NTRS)

    Tew, Roy; Ibrahim, Mounir; Danila, Daniel; Simon, Terry; Mantell, Susan; Sun, Liyong; Gedeon, David; Kelly, Kevin; McLean, Jeffrey; Wood, Gary; Qiu, Songgang

    2007-01-01

    A segmented involute-foil regenerator has been designed, microfabricated and tested in an oscillating-flow rig with excellent results. During the Phase I effort, several approximations of parallel-plate regenerator geometry were chosen as potential candidates for a new microfabrication concept. Potential manufacturers and processes were surveyed. The selected concept consisted of stacked segmented-involute-foil disks (or annular portions of disks), originally to be microfabricated from stainless-steel via the LiGA (lithography, electroplating, and molding) process and EDM (electric discharge machining). During Phase II, re-planning of the effort led to test plans based on nickel disks, microfabricated via the LiGA process, only. A stack of nickel segmented-involute-foil disks was tested in an oscillating-flow test rig. These test results yielded a performance figure of merit (roughly the ratio of heat transfer to pressure drop) of about twice that of the 90% random fiber currently used in small 100 W Stirling space-power convertors in the Reynolds Number range of interest (50-100). A Phase III effort is now underway to fabricate and test a segmented-involute-foil regenerator in a Stirling convertor. Though funding limitations prevent optimization of the Stirling engine geometry for use with this regenerator, the Sage computer code will be used to help evaluate the engine test results. Previous Sage Stirling model projections have indicated that a segmented-involute-foil regenerator is capable of improving the performance of an optimized involute-foil engine by 6-9%; it is also anticipated that such involute-foil geometries will be more reliable and easier to manufacture with tight-tolerance characteristics, than random-fiber or wire-screen regenerators. Beyond the near-term Phase III regenerator fabrication and engine testing, other goals are (1) fabrication from a material suitable for high temperature Stirling operation (up to 850 C for current engines; up to

  11. A Microfabricated Involute-Foil Regenerator for Stirling Engines

    NASA Technical Reports Server (NTRS)

    Tew, Roy; Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Kelly, Kevin; McLean, Jeffrey; Qiu, Songgang

    2007-01-01

    A segmented involute-foil regenerator has been designed, microfabricated and tested in an oscillating-flow rig with excellent results. During the Phase I effort, several approximations of parallel-plate regenerator geometry were chosen as potential candidates for a new microfabrication concept. Potential manufacturers and processes were surveyed. The selected concept consisted of stacked segmented-involute-foil disks (or annular portions of disks), originally to be microfabricated from stainless-steel via the LiGA (lithography, electroplating, and molding) process and EDM. During Phase II, re-planning of the effort led to test plans based on nickel disks, microfabricated via the LiGA process, only. A stack of nickel segmented-involute-foil disks was tested in an oscillating-flow test rig. These test results yielded a performance figure of merit (roughly the ratio of heat transfer to pressure drop) of about twice that of the 90 percent random fiber currently used in small approx.100 W Stirling space-power convertors-in the Reynolds Number range of interest (50 to 100). A Phase III effort is now underway to fabricate and test a segmented-involute-foil regenerator in a Stirling convertor. Though funding limitations prevent optimization of the Stirling engine geometry for use with this regenerator, the Sage computer code will be used to help evaluate the engine test results. Previous Sage Stirling model projections have indicated that a segmented-involute-foil regenerator is capable of improving the performance of an optimized involute-foil engine by 6 to 9 percent; it is also anticipated that such involute-foil geometries will be more reliable and easier to manufacture with tight-tolerance characteristics, than random-fiber or wire-screen regenerators. Beyond the near-term Phase III regenerator fabrication and engine testing, other goals are (1) fabrication from a material suitable for high temperature Stirling operation (up to 850 C for current engines; up to 1200 C

  12. Carbothermic Aluminum Production Using Scrap Aluminum As A Coolant

    DOEpatents

    LaCamera, Alfred F.

    2002-11-05

    A process for producing aluminum metal by carbothermic reduction of alumina ore. Alumina ore is heated in the presence of carbon at an elevated temperature to produce an aluminum metal body contaminated with about 10-30% by wt. aluminum carbide. Aluminum metal or aluminum alloy scrap then is added to bring the temperature to about 900-1000.degree. C. and precipitate out aluminum carbide. The precipitated aluminum carbide is filtered, decanted, or fluxed with salt to form a molten body having reduced aluminum carbide content.

  13. MTBE OXIDATION BY BIFUNCTIONAL ALUMINUM

    EPA Science Inventory

    Bifunctional aluminum, prepared by sulfating zero-valent aluminum with sulfuric acid, has a dual functionality of simultaneously decomposing both reductively- and oxidatively-degradable contaminants. In this work, the use of bifunctional aluminum for the degradation of methyl te...

  14. High energy X-ray diffraction measurement of residual stresses in a monolithic aluminum clad uranium–10 wt% molybdenum fuel plate assembly

    SciTech Connect

    D. W. Brown; M. A. Okuniewski; J. D. Almer; L. Balogh; B. Clausen; J. S. Okasinski; B. H. Rabin

    2013-10-01

    Residual stresses are expected in monolithic, aluminum clad uranium 10 wt% molybdenum (U–10Mo) nuclear fuel plates because of the large mismatch in thermal expansion between the two bonded materials. The full residual stress tensor of the U–10Mo foil in a fuel plate assembly was mapped with 0.1 mm resolution using high-energy (86 keV) X-ray diffraction. The in-plane stresses in the U–10Mo foil are strongly compressive, roughly -250 MPa in the longitudinal direction and -140 MPa in the transverse direction near the center of the fuel foil. The normal component of the stress is weakly compressive near the center of the foil and tensile near the corner. The disparity in the residual stress between the two in-plane directions far from the edges and the tensile normal stress suggest that plastic deformation in the aluminum cladding during fabrication by hot isostatic pressing also contributes to the residual stress field. A tensile in-plane residual stress is presumed to be present in the aluminum cladding to balance the large in-plane compressive stresses in the U–10Mo fuel foil, but cannot be directly measured with the current technique due to large grain size.

  15. High energy density aluminum battery

    SciTech Connect

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  16. Is the Aluminum Hypothesis Dead?

    PubMed Central

    2014-01-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust. PMID:24806729

  17. Gas Foil Bearings for Space Propulsion Nuclear Electric Power Generation

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.; DellaCorte, Christopher

    2006-01-01

    The choice of power conversion technology is critical in directing the design of a space vehicle for the future NASA mission to Mars. One candidate design consists of a foil bearing supported turbo alternator driven by a helium-xenon gas mixture heated by a nuclear reactor. The system is a closed-loop, meaning there is a constant volume of process fluid that is sealed from the environment. Therefore, foil bearings are proposed due to their ability to use the process gas as a lubricant. As such, the rotor dynamics of a foil bearing supported rotor is an important factor in the eventual design. The current work describes a rotor dynamic analysis to assess the viability of such a system. A brief technology background, assumptions, analyses, and conclusions are discussed in this report. The results indicate that a foil bearing supported turbo alternator is possible, although more work will be needed to gain knowledge about foil bearing behavior in helium-xenon gas.

  18. Misalignment in Gas Foil Journal Bearings: An Experimental Study

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.

    2008-01-01

    As gas foil journal bearings become more prevalent in production machines, such as small gas turbine propulsion systems and microturbines, system-level performance issues must be identified and quantified in order to provide for successful design practices. Several examples of system-level design parameters that are not fully understood in foil bearing systems are thermal management schemes, alignment requirements, balance requirements, thrust load balancing, and others. In order to address some of these deficiencies and begin to develop guidelines, this paper presents a preliminary experimental investigation of the misalignment tolerance of gas foil journal bearing systems. Using a notional gas foil bearing supported rotor and a laser-based shaft alignment system, increasing levels of misalignment are imparted to the bearing supports while monitoring temperature at the bearing edges. The amount of misalignment that induces bearing failure is identified and compared to other conventional bearing types such as cylindrical roller bearings and angular contact ball bearings. Additionally, the dynamic response of the rotor indicates that the gas foil bearing force coefficients may be affected by misalignment.

  19. Anodizing Aluminum with Frills.

    ERIC Educational Resources Information Center

    Doeltz, Anne E.; And Others

    1983-01-01

    "Anodizing Aluminum" (previously reported in this journal) describes a vivid/relevant laboratory experience for general chemistry students explaining the anodizing of aluminum in sulfuric acid and constrasting it to electroplating. Additions to this procedure and the experiment in which they are used are discussed. Reactions involved are…

  20. The survivability of phyllosilicates and carbonates impacting Stardust Al foils: Facilitating the search for cometary water

    NASA Astrophysics Data System (ADS)

    Wozniakiewicz, Penelope J.; Ishii, Hope A.; Kearsley, Anton T.; Bradley, John P.; Price, Mark. C.; Burchell, Mark J.; Teslich, Nick; Cole, Mike J.

    2015-12-01

    Comet 81P/Wild 2 samples returned by NASA's Stardust mission provide an unequalled opportunity to study the contents of, and hence conditions and processes operating on, comets. They can potentially validate contentious interpretations of cometary infrared spectra and in situ mass spectrometry data: specifically the identification of phyllosilicates and carbonates. However, Wild 2 dust was collected via impact into capture media at ~6 km s-1, leading to uncertainty as to whether these minerals were captured intact, and, if subjected to alteration, whether they remain recognizable. We simulated Stardust Al foil capture conditions using a two-stage light-gas gun, and directly compared transmission electron microscope analyses of pre- and postimpact samples to investigate survivability of lizardite and cronstedtite (phyllosilicates) and calcite (carbonate). We find the phyllosilicates do not survive impact as intact crystalline materials but as moderately to highly vesiculated amorphous residues lining resultant impact craters, whose bulk cation to Si ratios remain close to that of the impacting grain. Closer inspection reveals variation in these elements on a submicron scale, where impact-induced melting accompanied by reducing conditions (due to the production of oxygen scavenging molten Al from the target foils) has resulted in the production of native silicon and Fe- and Fe-Si-rich phases. In contrast, large areas of crystalline calcite are preserved within the calcite residue, with smaller regions of vesiculated, Al-bearing calcic glass. Unambiguous identification of calcite impactors on Stardust Al foil is therefore possible, while phyllosilicate impactors may be inferred from vesiculated residues with appropriate bulk cation to Si ratios. Finally, we demonstrate that the characteristic textures and elemental distributions identifying phyllosilicates and carbonates by transmission electron microscopy can also be observed by state-of-the-art scanning electron

  1. The Aluminum Smelting Process

    PubMed Central

    2014-01-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development. PMID:24806722

  2. An experimental and theoretical study of structural damping in compliant foil bearings

    NASA Technical Reports Server (NTRS)

    Ku, C.-P. Roger

    1994-01-01

    This paper describes an experimental investigation into the dynamic characteristics of corrugated foil (bump foil) strips used in compliant surface foil bearings. This study provided and opportunity to quantify the structural damping of bump foil strips. The experimental data were compared to results obtained by a theoretical model developed earlier. The effects of bearing design parameters, such as static loads, dynamic displacement amplitudes, bump configurations, pivot locations, surface coatings, and lubricant were also evaluated. An understanding of the dynamic characteristics of bump foil strips resulting from this work offers designers a means for enhancing the design of high-performance compliant foil bearings.

  3. Plasma diagnostics for x-ray driven foils at Z

    SciTech Connect

    Heeter, R F; Bailey, J E; Cuneo, M E; Emig, J; Foord, M E; Springer, P T; Thoe, R S

    2000-06-17

    We report the development of techniques to diagnose plasmas produced by X-ray photoionization of thin foils placed near the Z-pinch on the Sandia Z Machine. The development of 100+ TW X-ray sources enables access to novel plasma regimes, such as the photoionization equilibrium. To diagnose these plasmas one must simultaneously characterize both the foil and the driving pinch. The desired photoionized plasma equilibrium is only reached transiently for a 2-ns window, placing stringent requirements on diagnostic synchronization. We have adapted existing Sandia diagnostics and fielded an additional gated 3-crystal Johann spectrometer with dual lines of sight to meet these requirements. We present sample data from experiments in which 1 cm, 180 eV tungsten pinches photoionized foils composed of 200{angstrom} Fe and 300{angstrom} NaF co-mixed and sandwiched between 1000{angstrom} layers of Lexan (CHO), and discuss the application of this work to benchmarking astrophysical models.

  4. Interpreting Evidence.

    ERIC Educational Resources Information Center

    Munsart, Craig A.

    1993-01-01

    Presents an activity that allows students to experience the type of discovery process that paleontologists necessarily followed during the early dinosaur explorations. Students are read parts of a story taken from the "American Journal of Science" and interpret the evidence leading to the discovery of Triceratops and Stegosaurus. (PR)

  5. Performing Interpretation

    ERIC Educational Resources Information Center

    Kothe, Elsa Lenz; Berard, Marie-France

    2013-01-01

    Utilizing a/r/tographic methodology to interrogate interpretive acts in museums, multiple areas of inquiry are raised in this paper, including: which knowledge is assigned the greatest value when preparing a gallery talk; what lies outside of disciplinary knowledge; how invitations to participate invite and disinvite in the same gesture; and what…

  6. Interpreting Metonymy.

    ERIC Educational Resources Information Center

    Pankhurst, Anne

    1994-01-01

    This paper examines some of the problems associated with interpreting metonymy, a figure of speech in which an attribute or commonly associated feature is used to name or designate something. After defining metonymy and outlining the principles of metonymy, the paper explains the differences between metonymy, synecdoche, and metaphor. It is…

  7. High Temperature Performance Evaluation of a Compliant Foil Seal

    NASA Technical Reports Server (NTRS)

    Salehi, Mohsen; Heshmat, Hooshang; Walton, James F., II

    2001-01-01

    The key points to be gleaned from the effort reported herein are that the CFS (Compliant Foil Seal) has been demonstrated in conjunction with a foil bearing in a small gas turbine simulator at temperatures as high as 1000 F and outperformed a comparable brush seal. Having demonstrated the feasibility of the CFS, it would appear that this new seal design has application potential in a wide range of machines. What remains is to demonstrate performance at higher pressure ratios, consistent performance at large rotor excursions and the ability to manufacture the seal in much larger sizes exceeding by an order of magnitude that which has been tested to date.

  8. Prediction of forming limit strains of thin foils using shim

    NASA Astrophysics Data System (ADS)

    Joshi, Sanket Vivek; Bade, Rohit A.; Narasimhan, K.

    2013-12-01

    Thin foils of metallic alloys find utility in metallic thermal protection systems, such as honeycomb structures. Understanding the formability of these thin foils becomes imperative so as to design accurate tooling and also to ensure mechanical robustness of the honeycomb structures during service. It has been found that, obtaining the precise limit strains of these foils directly using the conventional limiting dome test tooling is difficult, because of the excessive draw in and wrinkling that occurs during the punch travel, resulting in erroneous measurement or prediction of limit strains. To address this issue, the blank over blank stacking methodology was developed, which helped keep the draw-in and wrinkling at negligible and thus acceptable levels. Although the blank over blank stacking methodology offers a way to predict and measure limit strains, the same may not be accurate enough due to the effect the substrate properties may impose on the thin foil. To avoid this effect, a different methodology has been proposed herein, which uses a shim stacked over the blank to avoid draw in of these foil blanks and thus help accurate clamping of the blank between the die and blank holder. It is thus understood that either a critical local or global increase in the thickness of the blank material in and around the draw bead is essential to obtain effective clamping of foil and to avoid draw-in and wrinkling. Although, miniaturized hemispherical dome tests may be beneficial for obtaining limit strains as far as foils are concerned, the methodologies proposed herein provide a route to obtaining the same using available equipment, thus saving resources and time involved in development of new miniaturized testing devices. The forming limit strains of thin foils of IN 718 (inconel) alloy having a thickness of 50μm, C263 (nimonic) alloy having a thickness of 100μm and CP Ti (commercially pure titanium) having a thickness of 200μm have been predicted using this methodology

  9. Similarities and differences between the solar wind light noble gas compositions determined on Apollo 15 SWC foils and on NASA Genesis targets

    NASA Astrophysics Data System (ADS)

    Vogel, N.; Bochsler, P.; Bühler, F.; Heber, V. S.; Grimberg, A.; Baur, H.; Horstmann, M.; Bischoff, A.; Wieler, R.

    2015-10-01

    We compare the solar wind (SW) He, Ne, and Ar compositions collected during the Apollo Solar Wind Composition (SWC) experiments (1969-1972; Al- & Pt-foils) and the Genesis mission (2002-2004; so-called DOS targets considered here). While published SW 20Ne/22Ne and 36Ar/38Ar ratios of both data sets agree, differences exist in the 4He/3He, 4He/20Ne, and 20Ne/36Ar ratios. However, 20Ne/36Ar ratios from Apollo-16 Pt-foils, exclusively adopted as SW values by the SWC team, are consistent with the Genesis results. We investigate if the differences indicate a variability of the SW over the course of about 30 yr, or systematic biases of the two data sets, which were collected in different environments and measured several decades apart in different laboratories (University of Bern; ETH Zurich). New measurements of Apollo-15 SWC aluminum foils in Zurich generally agree with the original measurements performed in Bern. Zurich samples show slightly lower 4He concentrations suggesting a few percent of diffusive loss of 4He during storage of the foils. A 3% difference between the He isotopic ratios measured in Bern and in Zurich possibly represents an analytical bias between the laboratories. The low SW 4He/20Ne and 20Ne/36Ar ratios in Apollo-15 Al-foils compared to Genesis data are consistent with a mixture of Genesis-like SW and noble gases from small amounts of lunar dust. Our data suggest that the mean SW He, Ne, and Ar isotopic and elemental compositions have not significantly changed between the overall Apollo and Genesis mission collection periods.

  10. Clinical biochemistry of aluminum

    SciTech Connect

    King, S.W.; Savory, J.; Wills, M.R.

    1981-05-01

    Aluminum toxicity has been implicated in the pathogenesis of a number of clinical disorders in patients with chronic renal failure on long-term intermittent hemodialysis treatment. The predominant disorders have been those involving either bone (osteomalacic dialysis osteodystrophy) or brain (dialysis encephalopathy). In nonuremic patients, an increased brain aluminum concentration has been implicated as a neurotoxic agent in the pathogenesis of Alzheimer's disease and was associated with experimental neurofibrillary degeneration in animals. The brain aluminum concentrations of patients dying with the syndrome of dialysis encephalopathy (dialysis dementia) are significantly higher than in dialyzed patients without the syndrome and in nondialyzed patients. Two potential sources for the increased tissue content of aluminum in patients on hemodialysis have been proposed: (1) intestinal absorption from aluminum containing phosphate-binding gels, and (2) transfer across the dialysis membrane from aluminum in the water used to prepare the dialysate. These findings, coupled with our everyday exposure to the ubiquitous occurrence of aluminum in nature, have created concerns over the potential toxicity of this metal.

  11. Measurement of H{sup {minus}}, H{sup 0}, and H{sup +} yields produced by foil stripping of 800-MeV H{sup {minus}} ions

    SciTech Connect

    Gulley, M.S.; Keating, P.B.; Bryant, H.C.; MacKerrow, E.P.; Miller, W.A.; Rislove, D.C.; Cohen, S.; Donahue, J.B.; Fitzgerald, D.H.; Frankle, S.C.; Funk, D.J.; Hutson, R.L.; Macek, R.J.; Plum, M.A.; Stanciu, N.G.; van Dyck, O.B.; Wilkinson, C.A.; Planner, C.W.

    1996-05-01

    Measurements of H{sup {minus}} stripping and H{sup 0} excited-state production for a wide range of foil thicknesses and experimental conditions are reported. An 800-MeV H{sup {minus}} beam was passed through carbon or aluminum oxide foils of thicknesses ranging from 10 to 550 {mu}g/cm{sup 2} and the excited states produced were analyzed by field stripping in a special magnet downstream of the foil. The foil thicknesses were independently determined. The H{sup 0} atoms emerging in excited states with {ital n}{approx_gt}2 can be stripped to protons in fields of up to 1.3 T. The yield of excited states as a function of foil thickness and the cross sections for the various interactions are presented. The cross-section ratio of double to single ionization of H{sup {minus}} in carbon is found to be (1.8{plus_minus}0.9){percent}. {copyright} {ital 1996 The American Physical Society.}

  12. Cast Aluminum Bonding Study

    DTIC Science & Technology

    1988-05-01

    fabricated using P?-’r;est11 bur)ld II19 te(hnll I Oly with 6 cIsL nqs. The cast a lumi num alloy used was A357 . The sur- face preparation was phosphoric acid...from a cast aluminum alloy designated A357 . The bonding surfaces of the adherends were prepared using PAA. One primer and two adhesives considered...System, Cast Aluminum Lap Shear 18 11 Bond Area of 350°F Adhesive System, Cast Aluminum Lap Shear 19 vi LIST OF TABLES TABLE PAGE 1 A357 Chemical

  13. Purifying Aluminum by Vacuum Distillation

    NASA Technical Reports Server (NTRS)

    Du Fresne, E. R.

    1985-01-01

    Proposed method for purifying aluminum employs one-step vacuum distillation. Raw material for process impure aluminum produced in electrolysis of aluminum ore. Impure metal melted in vacuum. Since aluminum has much higher vapor pressure than other constituents, boils off and condenses on nearby cold surfaces in proportions much greater than those of other constituents.

  14. Effect of oxygen barrier coatings on oxidation and embrittlement of Ti-6Al-2Sn-4Zr-2Mo foil in heat shield applications

    NASA Technical Reports Server (NTRS)

    Clark, R. K.; Unnam, J.; Wiedemann, K. E.

    1986-01-01

    Because of the loss of ductility with exposure to oxidizing conditions, long time applications of titanium alloys have been limited to temperatures below 700 K and short time applications have been limited to temperatures below 815 K. Oxygen barrier coatings for shielding Ti-6Al-2Sn-4Zr-2Mo alloy from oxidation during exposure to high temperatures were studied using foil gage specimens. The coatings included micrometer-thick sputtered SiO2 and chemical-vapor-deposited silicate layers both with and without an aluminum basecoat. The oxidation rates and resistance to embrittlement of the coated specimens were significantly better than those of the uncoated specimens.

  15. Design, Fabrication and Performance of Open Source Generation I and II Compliant Hydrodynamic Gas Foil Bearings

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Radil, Kevin C.; Bruckner, Robert J.; Howard, S. Adam

    2007-01-01

    Foil gas bearings are self-acting hydrodynamic bearings made from sheet metal foils comprised of at least two layers. The innermost top foil layer traps a gas pressure film that supports a load while a layer or layers underneath provide an elastic foundation. Foil bearings are used in many lightly loaded, high-speed turbo-machines such as compressors used for aircraft pressurization, and small micro-turbines. Foil gas bearings provide a means to eliminate the oil system leading to reduced weight and enhanced temperature capability. The general lack of familiarity of the foil bearing design and manufacturing process has hindered their widespread dissemination. This paper reviews the publicly available literature to demonstrate the design, fabrication and performance testing of both first and second generation bump style foil bearings. It is anticipated that this paper may serve as an effective starting point for new development activities employing foil bearing technology.

  16. Interpretive Medicine

    PubMed Central

    Reeve, Joanne

    2010-01-01

    Patient-centredness is a core value of general practice; it is defined as the interpersonal processes that support the holistic care of individuals. To date, efforts to demonstrate their relationship to patient outcomes have been disappointing, whilst some studies suggest values may be more rhetoric than reality. Contextual issues influence the quality of patient-centred consultations, impacting on outcomes. The legitimate use of knowledge, or evidence, is a defining aspect of modern practice, and has implications for patient-centredness. Based on a critical review of the literature, on my own empirical research, and on reflections from my clinical practice, I critique current models of the use of knowledge in supporting individualised care. Evidence-Based Medicine (EBM), and its implementation within health policy as Scientific Bureaucratic Medicine (SBM), define best evidence in terms of an epistemological emphasis on scientific knowledge over clinical experience. It provides objective knowledge of disease, including quantitative estimates of the certainty of that knowledge. Whilst arguably appropriate for secondary care, involving episodic care of selected populations referred in for specialist diagnosis and treatment of disease, application to general practice can be questioned given the complex, dynamic and uncertain nature of much of the illness that is treated. I propose that general practice is better described by a model of Interpretive Medicine (IM): the critical, thoughtful, professional use of an appropriate range of knowledges in the dynamic, shared exploration and interpretation of individual illness experience, in order to support the creative capacity of individuals in maintaining their daily lives. Whilst the generation of interpreted knowledge is an essential part of daily general practice, the profession does not have an adequate framework by which this activity can be externally judged to have been done well. Drawing on theory related to the

  17. Corrosion Inhibitors for Aluminum.

    ERIC Educational Resources Information Center

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  18. Walnut Hulls Clean Aluminum

    NASA Technical Reports Server (NTRS)

    Colberg, W. R.; Gordon, G. H.; Jackson, C. H.

    1984-01-01

    Hulls inflict minimal substrate damage. Walnut hulls found to be best abrasive for cleaning aluminum surfaces prior to painting. Samples blasted with walnut hulls showed no compressive stress of surface.

  19. The contribution of familiarity to recognition memory is a function of test format when using similar foils.

    PubMed

    Migo, Ellen; Montaldi, Daniela; Norman, Kenneth A; Quamme, Joel; Mayes, Andrew

    2009-06-01

    Patient Y.R., who suffered hippocampal damage that disrupted recollection but not familiarity, was impaired on a yes/no (YN) object recognition memory test with similar foils. However, she was not impaired on a forced-choice corresponding (FCC) version of the test that paired targets with corresponding similar foils (Holdstock et al., 2002). This dissociation is explained by the Complementary Learning Systems (CLS) neural-network model (Norman & O'Reilly, 2003) if recollection is impaired but familiarity is preserved. The CLS model also predicts that participants relying exclusively on familiarity should be impaired on forced-choice noncorresponding (FCNC) tests, where targets are presented with foils similar to other targets. The present study tests these predictions for all three test formats (YN, FCC, FCNC) in normal participants using two variants of the remember/know procedure. As predicted, performance using familiarity alone was significantly worse than standard recognition on the YN and FCNC tests, but not on the FCC test. Recollection in the form of recall-to-reject was the major process driving YN recognition. This adds support to the interpretation of patient data, according to which hippocampal damage causes a recollection deficit that leads to poor performance on the YN test relative to FCC.

  20. Age Differences in Depth of Retrieval: Memory for Foils

    ERIC Educational Resources Information Center

    Jacoby, L.L.; Shimizu, Y.; Velanova, K.; Rhodes, M.G.

    2005-01-01

    Control over memory can be achieved in two ways: by constraining retrieval such that only sought after information comes to mind or, alternatively, by means of post-access monitoring. We used a memory-for-foils paradigm to gain evidence of differences in retrieval constraints. In this paradigm, participants studied words under deep or shallow…

  1. The Visualization of Infrared Radiation Using Thermal Sensitive Foils

    ERIC Educational Resources Information Center

    Bochnícek, Zdenek

    2013-01-01

    This paper describes a set of demonstration school experiments where infrared radiation is detected using thermal sensitive foils. The possibility of using standard glass lenses for infrared imaging is discussed in detail. It is shown that with optic components made from glass, infrared radiation up to 2.5 µm of wavelength can be detected. The…

  2. Exploding metallic foil fuse modeling at Los Alamos

    SciTech Connect

    Lindemuth, I.R.; Reinovsky, R.E.; Goforth, J.H.

    1989-01-01

    A ''first-principles'' computational model of exploding metallic foil behavior has been developed at Los Alamos. The model couples zero-dimensional magnetohydrodynamics with ohmic heating and electrical circuit equations and uses the Los Alamos SESAME atomic data base computer library to determine the foil material's temperature- and density-dependent pressure, specific energy, and electrical conductivity. The model encompasses many previously successful empirical models and offers plausible physical explanations of phenomena not treated by the empirical models. In addition to addressing the electrical circuit performance of an exploding foil, the model provides information on the temporal evolution of the foil material's density, temperature, pressure, electrical conductivity, and expansion and translational velocities. In this paper, we report the physical insight gained by computational studies of two opening switch concepts being developed for application in an FCG-driven 1-MJ-class imploding plasma z-pinch experiment. The first concept considered is a ''conventional'' electrically exploded fuse, which has been demonstrated to operate at 16 MA driven by the 15-MJ-class FCG to be used in the 1 MJ implosion experiment. The second concept considered is a Type 2 explosively formed fuse (EFF), which has been demonstrated to operate at the 8 MA level by a 1-MJ-class FCG.

  3. Tribalism as a Foiled Factor of Africa Nation-Building

    ERIC Educational Resources Information Center

    Okogu, J. O.; Umudjere, S. O.

    2016-01-01

    This paper tends to examine tribalism as a foiled factor on Africa nation-building and proffers useful tips to salvaging the Africa land from this deadly social problem. Africans in times past had suffered enormous attacks, injuries, losses, deaths, destruction of properties and human skills and ideas due to the presence of tribalistic views in…

  4. Secret in the Margins: Rutherford's Gold Foil Experiment

    ERIC Educational Resources Information Center

    Aydin, Sevgi; Hanuscin, Deborah L.

    2011-01-01

    In this article, the authors describe a lesson that uses the 5E Learning Cycle to help students not only understand the atomic model but also how Ernest Rutherford helped develop it. The lesson uses Rutherford's gold foil experiment to focus on three aspects of the nature of science: the empirical nature of science, the tentativeness of scientific…

  5. Fullurene-oxygen-iodine laser (FOIL): physical principles

    NASA Astrophysics Data System (ADS)

    Danilov, Oleg B.; Belousova, Inna M.; Mak, Artur A.; Belousov, Vlidilen P.; Grenishin, A. S.; Kiselev, V. M.; Krys'ko, A. V.; Murav'eva, T. D.; Ponomarev, Alexander N.; Sosnov, Eugene N.

    2005-03-01

    The paper considers the physical principles of developing the fullerene - oxygen - iodine laser (FOIL) with optical (sunlight in particular) pumping. Kinetic scheme of such a laser is considered. It is shown that the utmost efficiency of FOIL may exceed 40% of the energy, absorbed by fullerenes. Presented are the experimental results of singlet oxygen generation in liquid media (solutions and suspensions) and in solid-state structures, containing either fullerenes or fullerene-like nanopartickles (FNP). In experiment was shown the possibility of the singlet oxygen transfer to the gaseous phase by means of organizing of the solution (suspension) the boiling as well as of the gasodynamic wave of desorption from the solid-state structures, containing fullerenes or FNP. We present the preliminary experimental results of pulsed generation in optically pumped FOIL with the use of primary photodissociation of iodide for preparation of the atomic iodine in the generation zone. In the experiments on FOIL generation was implemented the principle of spectral separation of optical pumping.

  6. Fullerene-oxygen-iodine laser (FOIL): physical principles

    NASA Astrophysics Data System (ADS)

    Danilov, Oleg B.; Belousova, Inna M.; Mak, Artur A.; Belousov, Vlidilen P.; Grenishin, A. S.; Kiselev, V. M.; Krys'ko, A. V.; Murav'eva, T. D.; Ponomarev, Alexander N.; Sosnov, Eugene N.

    2004-06-01

    The paper considers the physical principles of developing the fullerene-oxygen-iodine laser (FOIL) with optical (sunlight in particular) pumping. Kinetic scheme of such a laser is considered. It is shown that the utmost efficiency of FOIL may exceed 40% of the energy, absorbed by fullerenes. Presented are the experimental results of singlet oxygen generation in liquid media (solutions and suspensions) and in solid-state structures, containing either fullerenes or fullerene-like nanoparticles (FNP). In experiment was shown the possibility of the singlet oxygen transfer to the gaseous phase by means of organizing of the solution (suspension) the boiling as well as of the gasodynamic wave of desorption from the solid-state structures, containing fullerenes or FNP. We present the preliminary experimental results of pulsed generation in optically pumped FOIL with the use of primary photodissociation of iodide for preparation of the atomic iodine in the generation zone. In the experiments on FOIL generation was implemented the principle of spectral separation of optical pumping.

  7. Fullerene-oxygen-iodine laser (FOIL): physical principles

    NASA Astrophysics Data System (ADS)

    Danilov, Oleg B.; Belousova, Inna M.; Mak, Artur A.; Belousov, Vlidilen P.; Grenishin, A. S.; Kiselev, V. M.; Krys'ko, A. V.; Murav'eva, T. D.; Ponomarev, Alexander N.; Sosnov, Eugene N.

    2004-09-01

    The paper considers the physical principles of developing the fullerene-oxygen-iodine laser (FOIL) with optical (sunlight in particular) pumping. Kinetic scheme of such a laser is considered. It is shown that the utmost efficiency of FOIL may exceed 40% of the energy, absorbed by fullerenes. Presented are the experimental results of singlet oxygen generation in liquid media (solutions and suspensions) and in solid-state structures, containing either fullerenes or fullerene-like nanoparticles (FNP). In experiment was shown the possibility of the singlet oxygen transfer to the gaseous phase by means of organizing of the solution (suspension) the boiling as well as of the gasodynamic wave of desorption from the solid-state structures, containing fullerenes or FNP. We present the preliminary experimental results of pulsed generation in optically pumped FOIL with the use of primary photodissociation of iodide for preparation of the atomic iodine in the generation zone. In the experiments on FOIL generation was implemented the principle of spectral separation of optical pumping.

  8. Preparation of isotopic molybdenum foils utilizing small quantities of material

    NASA Astrophysics Data System (ADS)

    Lipski, A. R.; Lee, L. L.; Liang, J. F.; Mahon, J. C.

    1993-09-01

    A simple method utilizing a small amount of isotopic material for production of molybdenum foils is discussed. An e-gun is used in the procedure. The Mo powder undergoes reduction-sintering and melting-solidifying steps leading to the creation of a metallic droplet suitable for further cold rolling or vacuum deposition.

  9. Laser-induced structure formation on stretched polymer foils

    SciTech Connect

    Bityurin, Nikita; Arnold, Nikita; Baeuerle, Dieter; Arenholz, Enno

    2007-04-15

    Noncoherent structures that develop during UV laser ablation of stretched semicrystalline polymer foils are a very general phenomenon. A thermodynamic model based on stress relaxation within the modified layer of the polymer surface describes the main features of the observed phenomena, and, in particular, the dependence of the period of structures on laser wavelength, fluence, and number of laser pulses.

  10. Large deflection analysis of a tension-foil bearing

    NASA Technical Reports Server (NTRS)

    Elrod, David A.

    1996-01-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are as follows: rolling or sliding contact within the bearing has life-limiting consequences; and REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's. CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contacts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exist for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. Recently, a new tension-foil bearing configuration has been proposed for turbomachinery applications.

  11. Evaluation of Alumina-Forming Austenitic Foil for Advanced Recuperators

    SciTech Connect

    Pint, Bruce A; Brady, Michael P; Yamamoto, Yukinori; Santella, Michael L; Maziasz, Philip J; Matthews, Wendy

    2011-01-01

    A corrosion- and creep-resistant austenitic stainless steel has been developed for advanced recuperator applications. By optimizing the Al and Cr contents, the alloy is fully austenitic for creep strength while allowing the formation of a chemically stable external alumina scale at temperatures up to 900 C. An alumina scale eliminates long-term problems with the formation of volatile Cr oxy-hydroxides in the presence of water vapor in exhaust gas. As a first step in producing foil for primary surface recuperators, three commercially cast heats have been rolled to 100 m thick foil in the laboratory to evaluate performance in creep and oxidation testing. Results from initial creep testing are presented at 675 C and 750 C, showing excellent creep strength compared with other candidate foil materials. Laboratory exposures in humid air at 650 800 C have shown acceptable oxidation resistance. A similar oxidation behavior was observed for sheet specimens of these alloys exposed in a modified 65 kW microturbine for 2871 h. One composition that showed superior creep and oxidation resistance has been selected for the preparation of a commercial batch of foil. DOI: 10.1115/1.4002827

  12. Foil Bearing Starting Considerations and Requirements for Rotorcraft Engine Applications

    NASA Technical Reports Server (NTRS)

    Radil, Kevin C.; DellaCorte, Christopher

    2009-01-01

    Foil gas bearings under development for rotorcraft-sized, hot core engine applications have been susceptible to damage from the slow acceleration and rates typically encountered during the pre-ignition stage in conventional engines. Recent laboratory failures have been assumed to be directly linked to operating foil bearings below their lift-off speed while following conventional startup procedures for the engines. In each instance, the continuous sliding contact between the foils and shaft was believed to thermally overload the bearing and cause the engines to fail. These failures highlight the need to characterize required acceleration rates and minimum operating speeds for these applications. In this report, startup experiments were conducted with a large, rotorcraft engine sized foil bearing under moderate load and acceleration rates to identify the proper start procedures needed to avoid bearing failure. The results showed that a bearing under a 39.4 kPa static load can withstand a modest acceleration rate of 500 rpm/s and excessive loitering below the bearing lift-off speed provided an adequate solid lubricant is present.

  13. Foil bearing performance in liquid nitrogen and liquid oxygen

    NASA Technical Reports Server (NTRS)

    Genge, Gary G.; Saville, Marshall; Gu, Alston

    1993-01-01

    Space transfer vehicles and other power and propulsion systems require long-life turbopumps. Rolling-element bearings used in current turbopumps do not have sufficient life for these applications. Process fluid foil bearings have established long life, with exceptional reliability, over a wide range of temperatures and fluids in many high-speed turbomachinery applications. However, actual data on bearing performance in cryogenic fluids has been minimal. The National Aeronautics and Space Administration (NASA) and AlliedSignal Aerospace Systems and Equipment (ASE) have attempted to characterize the leaf-type compliant foil bearing in oxygen and nitrogen. The work performed under a joint internal research and development program between Marshall Space Flight Center (MSFC) and ASE demonstrated that the foil bearing has load capacities of at least 266 psi in liquid oxygen and 352 psi in liquid nitrogen. In addition, the bearing demonstrated a direct damping coefficient of 40 to 50 lb-sec/in. with a damping ratio of .7 to 1.4 in. liquid nitrogen using a bearing sized for upper-stage turbopumps. With the results from this testing and the years of successful use in air cycle machines and other applications, leaf-type compliant foil bearings are ready for testing in liquid oxygen turbopumps.

  14. Aluminum powder applications

    SciTech Connect

    Gurganus, T.B.

    1995-08-01

    Aluminum powders have physical and metallurgical characteristics related to their method of manufacture that make them extremely important in a variety of applications. They can propel rockets, improve personal hygiene, increase computer reliability, refine exotic alloys, and reduce weight in the family sedan or the newest Air Force fighter. Powders formed into parts for structural and non-structural applications hold the key to some of the most exciting new developments in the aluminum future.

  15. CORROSION PROTECTION OF ALUMINUM

    DOEpatents

    Dalrymple, R.S.; Nelson, W.B.

    1963-07-01

    Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred. (D.C.W.)

  16. Corrosion Protection of Aluminum

    DOEpatents

    Dalrymple, R. S.; Nelson, W. B.

    1963-07-01

    Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred.

  17. Improvements in Fabrication of Elastic Scattering Foils Used to Measure Neutron Yield by the Magnetic Recoil Spectrometer

    DOE PAGES

    Reynolds, H. G.; Schoff, M. E.; Farrell, M. P.; ...

    2016-08-01

    The magnetic recoil spectrometer uses a deuterated polyethylene polymer (CD2) foil to measure neutron yield in inertial confinement fusion experiments. Higher neutron yields in recent experiments have resulted in primary signal saturation in the detector CR-39 foils, necessitating the fabrication of thinner CD2 foils than established methods could provide. A novel method of fabricating deuterated polymer foils is described. The resulting foils are thinner, smoother, and more uniform in thickness than the foils produced by previous methods. Here, these new foils have successfully been deployed at the National Ignition Facility, enabling higher neutron yield measurements than previous foils, with nomore » primary signal saturation.« less

  18. Improvements in Fabrication of Elastic Scattering Foils Used to Measure Neutron Yield by the Magnetic Recoil Spectrometer

    SciTech Connect

    Reynolds, H. G.; Schoff, M. E.; Farrell, M. P.; Gatu Johnson, M.; Bionta, R. M.; Frenje, J. A.

    2016-08-01

    The magnetic recoil spectrometer uses a deuterated polyethylene polymer (CD2) foil to measure neutron yield in inertial confinement fusion experiments. Higher neutron yields in recent experiments have resulted in primary signal saturation in the detector CR-39 foils, necessitating the fabrication of thinner CD2 foils than established methods could provide. A novel method of fabricating deuterated polymer foils is described. The resulting foils are thinner, smoother, and more uniform in thickness than the foils produced by previous methods. Here, these new foils have successfully been deployed at the National Ignition Facility, enabling higher neutron yield measurements than previous foils, with no primary signal saturation.

  19. Electrochemical Stability of Carbon Fibers Compared to Metal Foils as Current Collectors for Lithium-Ion Batteries

    SciTech Connect

    Martha, Surendra K; Dudney, Nancy J; Kiggans, Jim; Nanda, Jagjit

    2012-01-01

    The electrochemical behaviors of highly conductive, fully-graphitic, semi-graphitic and non-graphitic carbon fibers were studied as the cathode current collectors of lithium batteries in standard electrolyte (alkyl carbonate/LiPF6) solutions and compared to bare aluminum (Al). All of these current collectors demonstrate a stable electrochemical behavior within the potential range of 2.5 to 5 V, due to passivation by surface films. Carbon fibers have comparable electrochemical stability of Al and may be used in place Al foil. While the carbon fibers do not contribute any irreversible or extra capacity when they are cycled below 4.5 V, for fully-graphitic and semi-graphitic fibers PF6 intercalation and deintercalation into the carbon fiber may occur when they are cycled at high potentials >4.5 V.

  20. Time-Of-Flight Mass Spectrometry of Laser Exploding Foil Initiated PETN Samples

    NASA Astrophysics Data System (ADS)

    Fajardo, Mario

    2015-06-01

    We report the results of time-of-flight mass spectrometry (TOFMS) measurements of the gaseous products of thin film PETN samples reacting in-vacuo. The PETN sample spots are produced by masked physical vapor deposition of PETN onto a first-surface aluminum mirror. A pulsed laser beam imaged through the soda lime glass mirror substrate converts the aluminum layer into a high-temperature high-pressure plasma which initiates chemical reactions in the overlying PETN sample. We had previously proposed to exploit differences in gaseous product chemical identities and molecular velocities to provide a chemically-based diagnostic for distinguishing between ``detonation-like'' and deflagration responses. Briefly: we expect in-vacuum detonations to produce hyperthermal (v ~ 10 km/s) thermodynamically-stable products such as N2, CO2, and H2O, and for deflagrations to produce mostly reaction intermediates, such as NO and NO2, with much slower molecular velocities - consistent with the expansion-quenched thermal decomposition of PETN. We observe primarily slow reaction intermediates (NO2, CH2NO3) at low laser pulse energies, the appearance of NO at intermediate laser pulse energies, and the appearance of hyperthemal CO/N2 at mass 28 amu at the highest laser pulse energies. However, these results are somewhat ambiguous, as the NO, NO2, and CH2NO3 intermediates persist and all species become hyperthermal at the higher laser pulse energies. Also, the purported CO/N2 signal at 28 amu may be contaminated by silicon ablated from the glass mirror substrate. We plan to mitigate these problems in future experiments by adopting the ``Buelow'' sample configuration which employs an intermediate foil barrier to shield the energetic material from the laser and the laser driven plasma. [RW PA#4930

  1. Terahertz radiation generation by nonlinear mixing of two laser beams over a thin foil

    SciTech Connect

    Chauhan, Santosh; Parashar, J.

    2015-07-31

    Terahertz radiation generation via nonlinear mixing of two laser beams incident over a thin metal foil is explored. The lasers exert a ponderomotive force on the electrons of metal foil at beat frequency which lies in the terahertz range. The metal foil acts as antenna, producing terahertz radiations, highly directional in nature.

  2. Continuous and breakdown currents in cold-plasma coated Mylar[reg sign] foils under irradiation by nonpenetrating electron beams

    SciTech Connect

    Gross, B.; Guenther, P. )

    1993-04-01

    Breakdown and flash-over effects are known to occur in thin polymer foils used as thermal blankets in space satellites, where they are exposed to irradiation by nonpenetrating space electrons. These effects are investigated by means of a Split Faraday Cup system mounted under an electron gun [1]. Continuous and breakdown currents are measured from a metal ring electrode at the surface of incidence and from a rear electrode, respectively. The equivalent circuit of the system is developed. Measurements were carried out on Mylar foils uncoated or coated with aluminum, plasma-deposited SiO[sub 2] or Si[sub 3]N[sub 4](p-SiO[sub 2] or p-Si[sub 3]N[sub 4]), or electron-beam evaporated SiO[sub 2]. It was found, that some plasma-deposited coatings form a conductive layer under irradiation and reduce breakdown effects. But after termination of the electron bombardment discharge and breakdown effects were observed for all samples except those aluminized on both surfaces.

  3. A Positron Annihilation Study of Corrosion of Aluminum and Aluminum Alloy by NaOH

    NASA Astrophysics Data System (ADS)

    Wu, Y. C.; Zhai, T.; Coleman, P. G.

    2012-08-01

    Corrosion of fully-annealed pure aluminum and a continuous-cast AA2037 aluminum alloy (solutionized and water quenched) in a 1M NaOH solution for various periods of time were analyzed with positron beam-based Doppler broadening spectroscopy. By varying the energy of the incident positron beam, corrosion-induced defects at different depths from the surface were detected. It was found that the Doppler-broadened annihilation line-width parameter was significantly increased near the surface of pure aluminum after corrosion, probably due to the interaction between positrons and nanometer-sized voids formed near the aluminum surface during corrosion. Examination by atomic force microscopy indicated that many pits were formed on the aluminum surface after corrosion. In contrast, a significant decrease in the line-width parameter was observed in AA2037 alloy after corrosion and interpreted as being caused by copper enrichment at the metal-oxide interface during corrosion; such enrichment at large cavity sites was confirmed by energy dispersion spectrometry.

  4. Shock experiments and numerical simulations on low energy portable electrically exploding foil accelerators

    SciTech Connect

    Saxena, A. K.; Kaushik, T. C.; Gupta, Satish C.

    2010-03-15

    Two low energy (1.6 and 8 kJ) portable electrically exploding foil accelerators are developed for moderately high pressure shock studies at small laboratory scale. Projectile velocities up to 4.0 km/s have been measured on Kapton flyers of thickness 125 {mu}m and diameter 8 mm, using an in-house developed Fabry-Perot velocimeter. An asymmetric tilt of typically few milliradians has been measured in flyers using fiber optic technique. High pressure impact experiments have been carried out on tantalum, and aluminum targets up to pressures of 27 and 18 GPa, respectively. Peak particle velocities at the target-glass interface as measured by Fabry-Perot velocimeter have been found in good agreement with the reported equation of state data. A one-dimensional hydrodynamic code based on realistic models of equation of state and electrical resistivity has been developed to numerically simulate the flyer velocity profiles. The developed numerical scheme is validated against experimental and simulation data reported in literature on such systems. Numerically computed flyer velocity profiles and final flyer velocities have been found in close agreement with the previously reported experimental results with a significant improvement over reported magnetohydrodynamic simulations. Numerical modeling of low energy systems reported here predicts flyer velocity profiles higher than experimental values, indicating possibility of further improvement to achieve higher shock pressures.

  5. Micro-nano filler metal foil on vacuum brazing of SiCp/Al composites

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Gao, Zeng; Niu, Jitai

    2016-06-01

    Using micro-nano (Al-5.25Si-26.7Cu)- xTi (wt%, x = 1.0, 1.5, 2.0, 2.5 and 3.0) foils as filler metal, the research obtained high-performance joints of aluminum matrix composites with high SiC particle content (60 vol%, SiCp/Al-MMCs). The effect of brazing process and Ti content on joint properties was investigated, respectively. The experimental results indicate that void free dense interface between SiC particle and metallic brazed seam with C-Al-Si-Ti product was readily obtained, and the joint shear strength enhanced with increasing brazing temperature from 560 to 580 °C or prolonging soaking time from 10 to 90 min. Sound joints with maximum shear strength of 112.5 MPa was achieved at 580 °C for soaking time of 90 min with (Al-5.25Si-26.7Cu)-2Ti filler, where Ti(AlSi)3 intermetallic is in situ strengthening phase dispersed in the joint and fracture occured in the filler metal layer. In this research, the beneficial effect of Ti addition into filler metal on improving wettability between SiC particle and metallic brazed seam was demonstrated, and capable welding parameters were broadened for SiCp/Al-MMCs with high SiC particle content.

  6. Exploring Mbar shock conditions and isochorically heated aluminum at the MEC end station of the LCLS

    SciTech Connect

    Fletcher, L. B.; Lee, H. J.; SLAC, aff; Barbrel, B.; Gauthier, M.; Galtier, E.; Nagler, B.; Doppner, T.; LePape, S.; Ma, T.; Pak, A.; Turnbull, D.; White, T.; Gregori, G.; Wei, M.; Falcone, R. W.; Heimann, P.; Zastrau, U.; Hastings, J. B.; Glenzer, S. H.

    2015-02-05

    Recent experiments performed at the Matter in Extreme Conditions end station (MEC) of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatter x-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using Velocity Interferometer System for Any Reflector (VISAR) have been measured. The combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.

  7. Aluminum, parathyroid hormone, and osteomalacia

    SciTech Connect

    Burnatowska-Hledin, M.A.; Kaiser, L.; Mayor, G.H.

    1983-01-01

    Aluminum exposure in man is unavoidable. The occurrence of dialysis dementia, vitamin D-resistant osteomalacia, and hypochromic microcytic anemia in dialysis patients underscores the potential for aluminum toxicity. Although exposure via dialysate and hyperalimentation leads to significant tissue aluminum accumulation, the ubiquitous occurrence of aluminum and the severe pathology associated with large aluminum burdens suggest that smaller exposures via the gastrointestinal tract and lungs could represent an important, though largely unrecognized, public health problem. It is clear that some aluminum absorption occurs with the ingestion of small amounts of aluminum in the diet and medicines, and even greater aluminum absorption is seen in individuals consuming large amounts of aluminum present in antacids. Aluminum absorption is enhanced in the presence of elevated circulating parathyroid hormone. In addition, elevated PTH leads to the preferential deposition of aluminum in brain and bone. Consequently, PTH is likely to be involved in the pathogenesis of toxicities in those organs. PTH excess also seems to lead to the deposition of aluminum in the parathyroid gland. The in vitro demonstration that aluminum inhibits parathyroid hormone release is consistent with the findings of a euparathyroid state in dialysis patients with aluminum related vitamin D-resistant osteomalacia. Nevertheless, it seems likely that hyperparathyroidism is at least initially involved in the pathogenesis of aluminum neurotoxicity and osteomalacia; the increases in tissue aluminum stores are followed by suppression of parathyroid hormone release, which is required for the evolution of osteomalacia. Impaired renal function is not a prerequisite for increased tissue aluminum burdens, nor for aluminum-related organ toxicity. Consequently, it is likely that these diseases will be observed in populations other than those with chronic renal disease.

  8. Thermal effects on the clearance and stiffness of foil journal bearings for a Brayton cycle turboalternator

    NASA Technical Reports Server (NTRS)

    Eshel, A.

    1972-01-01

    An analysis of foil journal bearings for a NASA Brayton Cycle Unit (BRU) is presented. The study represents an extension of previous work in that it includes the effects of thermal expansion of foil-bearing components, as well as an improved model of the influence of foil flexure. The results presented give the bearing film thickness, the bearing stiffness, and the foil tension as functions of the operating temperatures and the elasto-hydrodynamic and geometrical parameters pertinent to the design of BRU foil bearings. A computer program for the evaluation of design data and for parametric studies is included.

  9. Measurements of laser generated soft X-ray emission from irradiated gold foils

    NASA Astrophysics Data System (ADS)

    Davis, J. S.; Frank, Y.; Raicher, E.; Fraenkel, M.; Keiter, P. A.; Klein, S. R.; Drake, R. P.; Shvarts, D.

    2016-11-01

    Soft x-ray emission from laser irradiated gold foils was measured at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6 ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

  10. Measurements of laser generated soft X-ray emission from irradiated gold foils

    DOE PAGES

    Davis, J. S.; Frank, Y.; Raicher, E.; ...

    2016-08-22

    We measured soft x-ray emission from laser irradiated gold foils at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

  11. Dual scattering foil design for poly-energetic electron beams.

    PubMed

    Kainz, K K; Antolak, J A; Almond, P R; Bloch, C D; Hogstrom, K R

    2005-03-07

    The laser wakefield acceleration (LWFA) mechanism can accelerate electrons to energies within the 6-20 MeV range desired for therapy application. However, the energy spectrum of LWFA-generated electrons is broad, on the order of tens of MeV. Using existing laser technology, the therapeutic beam might require a significant energy spread to achieve clinically acceptable dose rates. The purpose of this work was to test the assumption that a scattering foil system designed for a mono-energetic beam would be suitable for a poly-energetic beam with a significant energy spread. Dual scattering foil systems were designed for mono-energetic beams using an existing analytical formalism based on Gaussian multiple-Coulomb scattering theory. The design criterion was to create a flat beam that would be suitable for fields up to 25 x 25 cm2 at 100 cm from the primary scattering foil. Radial planar fluence profiles for poly-energetic beams with energy spreads ranging from 0.5 MeV to 6.5 MeV were calculated using two methods: (a) analytically by summing beam profiles for a range of mono-energetic beams through the scattering foil system, and (b) by Monte Carlo using the EGS/BEAM code. The analytic calculations facilitated fine adjustments to the foil design, and the Monte Carlo calculations enabled us to verify the results of the analytic calculation and to determine the phase-space characteristics of the broadened beam. Results showed that the flatness of the scattered beam is fairly insensitive to the width of the input energy spectrum. Also, results showed that dose calculated by the analytical and Monte Carlo methods agreed very well in the central portion of the beam. Outside the useable field area, the differences between the analytical and Monte Carlo results were small but significant, possibly due to the small angle approximation. However, these did not affect the conclusion that a scattering foil system designed for a mono-energetic beam will be suitable for a poly

  12. Fatal aluminum phosphide poisoning.

    PubMed

    Anger, F; Paysant, F; Brousse, F; Le Normand, I; Develay, P; Gaillard, Y; Baert, A; Le Gueut, M A; Pepin, G; Anger, J P

    2000-03-01

    A 39-year-old man committed suicide by ingestion of aluminum phosphide, a potent mole pesticide, which was available at the victim's workplace. The judicial authority ordered an autopsy, which ruled out any other cause of death. The victim was discovered 10 days after the ingestion of the pesticide. When aluminum phosphide comes into contact with humidity, it releases large quantities of hydrogen phosphine (PH3), a very toxic gas. Macroscopic examination during the autopsy revealed a very important asphyxia syndrome with major visceral congestion. Blood, urine, liver, kidney, adrenal, and heart samples were analyzed. Phosphine gas was absent in the blood and urine but present in the brain (94 mL/g), the liver (24 mL/g), and the kidneys (41 mL/g). High levels of phosphorus were found in the blood (76.3 mg/L) and liver (8.22 mg/g). Aluminum concentrations were very high in the blood (1.54 mg/L), brain (36 microg/g), and liver (75 microg/g) compared to the usual published values. Microscopic examination revealed congestion of all the organs studied and obvious asphyxia lesions in the pulmonary parenchyma. All these results confirmed a diagnosis of poisoning by aluminum phosphide. This report points out that this type of poisoning is rare and that hydrogen phosphine is very toxic. The phosphorus and aluminum concentrations observed and their distribution in the different viscera are discussed in relation to data in the literature.

  13. Experimental investigation of heat transfer in a rivulet on the inclined foil

    NASA Astrophysics Data System (ADS)

    Cheverda, V. V.; Marchuk, I. V.; Karchevsky, A. L.; Orlik, E. V.; Kabov, O. A.

    2016-05-01

    Heat transfer at rivulet water flow over the constantan foil with the length of 80 mm, width of 35 mm, and thickness of 25 mm was studied experimentally. The foil surface temperature was measured by an IR-scanner. Distributions of heat flux density on the surface of the foil, where the liquid flowed, were obtained. To determine the heat flux density from the foil to liquid near the contact line, the Cauchy problem was solved for the stationary heat equation using the thermographic data. Calculation results showed that the maximal heat flux occurs in the area of the contact line and exceeds the average heat flux from the entire foil surface by several times. This is explained by the influx of heat from the periphery of foil to the rivulet due to the relatively high value of heat conductivity coefficient of the foil material and high evaporation rate in the region of the contact line.

  14. Radiation pressure acceleration of corrugated thin foils by Gaussian and super-Gaussian beams

    SciTech Connect

    Adusumilli, K.; Goyal, D.; Tripathi, V. K.

    2012-01-15

    Rayleigh-Taylor instability of radiation pressure accelerated ultrathin foils by laser having Gaussian and super-Gaussian intensity distribution is investigated using a single fluid code. The foil is allowed to have ring shaped surface ripples. The radiation pressure force on such a foil is non-uniform with finite transverse component F{sub r}; F{sub r} varies periodically with r. Subsequently, the ripple grows as the foil moves ahead along z. With a Gaussian beam, the foil acquires an overall curvature due to non-uniformity in radiation pressure and gets thinner. In the process, the ripple perturbation is considerably washed off. With super-Gaussian beam, the ripple is found to be more strongly washed out. In order to avoid transmission of the laser through the thinning foil, a criterion on the foil thickness is obtained.

  15. Simultaneous laser cutting and welding of metal foil to edge of a plate

    DOEpatents

    Pernicka, J.C.; Benson, D.K.; Tracy, C.E.

    1996-03-19

    A method is described for welding an ultra-thin foil to the edge of a thicker sheet to form a vacuum insulation panel comprising the steps of providing an ultra-thin foil having a thickness less than 0.002, providing a top plate having an edge and a bottom plate having an edge, clamping the foil to the edge of the plate wherein the clamps act as heat sinks to distribute heat through the foil, providing a laser, moving the laser relative to the foil and the plate edges to form overlapping weld beads to weld the foil to the plate edges while simultaneously cutting the foil along the weld line formed by the overlapping beads. 7 figs.

  16. Simultaneous laser cutting and welding of metal foil to edge of a plate

    DOEpatents

    Pernicka, John C.; Benson, David K.; Tracy, C. Edwin

    1996-01-01

    A method of welding an ultra-thin foil to the edge of a thicker sheet to form a vacuum insulation panel comprising the steps of providing an ultra-thin foil having a thickness less than 0.002, providing a top plate having an edge and a bottom plate having an edge, clamping the foil to the edge of the plate wherein the clamps act as heat sinks to distribute heat through the foil, providing a laser, moving the laser relative to the foil and the plate edges to form overlapping weld beads to weld the foil to the plate edges while simultaneously cutting the foil along the weld line formed by the overlapping beads.

  17. Measuring Submicron-Sized Fractionated Particulate Matter on Aluminum Impactor Disks

    PubMed Central

    Buchholz, Bruce A.; Zermeño, Paula; Hwang, Hyun-Min; Young, Thomas M.; Guilderson, Thomas P.

    2011-01-01

    Sub-micron sized airborne particulate matter (PM) is not collected well on regular quartz or glass fiber filter papers. We used a micro-orifice uniform deposit impactor (MOUDI) to fractionate PM into six size fractions and deposit it on specially designed high purity thin aluminum disks. The MOUDI separated PM into fractions 56–100 nm, 100–180 nm, 180–320 nm, 320–560 nm, 560–1000 nm, and 1000–1800 nm. Since the MOUDI has a low flow rate (30 L/min), it takes several days to collect sufficient carbon on 47 mm foil disks. The small carbon mass (20–200 microgram C) and large aluminum substrate (~25 mg Al) present several challenges to production of graphite targets for accelerator mass spectrometry (AMS) analysis. The Al foil consumes large amounts of oxygen as it is heated and tends to melt into quartz combustion tubes, causing gas leaks. We describe sample processing techniques to reliably produce graphitic targets for 14C-AMS analysis of PM deposited on Al impact foils. PMID:22228915

  18. Large area Germanium Tin nanometer optical film coatings on highly flexible aluminum substrates

    PubMed Central

    Jin, Lichuan; Zhang, Dainan; Zhang, Huaiwu; Fang, Jue; Liao, Yulong; Zhou, Tingchuan; Liu, Cheng; Zhong, Zhiyong; Harris, Vincent G.

    2016-01-01

    Germanium Tin (GeSn) films have drawn great interest for their visible and near-infrared optoelectronics properties. Here, we demonstrate large area Germanium Tin nanometer thin films grown on highly flexible aluminum foil substrates using low-temperature molecular beam epitaxy (MBE). Ultra-thin (10–180 nm) GeSn film-coated aluminum foils display a wide color spectra with an absorption wavelength ranging from 400–1800 nm due to its strong optical interference effect. The light absorption ratio for nanometer GeSn/Al foil heterostructures can be enhanced up to 85%. Moreover, the structure exhibits excellent mechanical flexibility and can be cut or bent into many shapes, which facilitates a wide range of flexible photonics. Micro-Raman studies reveal a large tensile strain change with GeSn thickness, which arises from lattice deformations. In particular, nano-sized Sn-enriched GeSn dots appeared in the GeSn coatings that had a thickness greater than 50 nm, which induced an additional light absorption depression around 13.89 μm wavelength. These findings are promising for practical flexible photovoltaic and photodetector applications ranging from the visible to near-infrared wavelengths. PMID:27667259

  19. Measuring Sub-micron Size Fractionated Particulate Matter on Aluminum Impactor Disks

    SciTech Connect

    Buchholz, B A; Zermeno, P; Hwang, H; Young, T M

    2009-07-28

    Sub-micron sized airborne particulate matter is not collected well on regular quartz or glass fiber filter papers. We used a micro-orifice uniform deposit impactor (MOUDI) to size fractionate particulate matter (PM) into six size fractions and deposit it on specially designed high purity thin aluminum disks. The MOUDI separated PM into fractions 56-100 nm, 100-180 nm, 180-320 nm, 320-560 nm, 560-1000 nm, and 1000-1800 nm. Since MOUDI have low flow rates, it takes several days to collect sufficient carbon on 47 mm foil disks. The small carbon mass (20-200 microgram C) and large aluminum substrate ({approx}25 mg Al) presents several challenges to production of graphite targets for accelerator mass spectrometry (AMS) analysis. The Al foil consumes large amounts of oxygen as it is heated and tends to melt into quartz combustion tubes, causing gas leaks. We describe sample processing techniques to reliably produce graphitic targets for {sup 14}C-AMS analysis of PM deposited on Al impact foils.

  20. Large area Germanium Tin nanometer optical film coatings on highly flexible aluminum substrates

    NASA Astrophysics Data System (ADS)

    Jin, Lichuan; Zhang, Dainan; Zhang, Huaiwu; Fang, Jue; Liao, Yulong; Zhou, Tingchuan; Liu, Cheng; Zhong, Zhiyong; Harris, Vincent G.

    2016-09-01

    Germanium Tin (GeSn) films have drawn great interest for their visible and near-infrared optoelectronics properties. Here, we demonstrate large area Germanium Tin nanometer thin films grown on highly flexible aluminum foil substrates using low-temperature molecular beam epitaxy (MBE). Ultra-thin (10–180 nm) GeSn film-coated aluminum foils display a wide color spectra with an absorption wavelength ranging from 400–1800 nm due to its strong optical interference effect. The light absorption ratio for nanometer GeSn/Al foil heterostructures can be enhanced up to 85%. Moreover, the structure exhibits excellent mechanical flexibility and can be cut or bent into many shapes, which facilitates a wide range of flexible photonics. Micro-Raman studies reveal a large tensile strain change with GeSn thickness, which arises from lattice deformations. In particular, nano-sized Sn-enriched GeSn dots appeared in the GeSn coatings that had a thickness greater than 50 nm, which induced an additional light absorption depression around 13.89 μm wavelength. These findings are promising for practical flexible photovoltaic and photodetector applications ranging from the visible to near-infrared wavelengths.

  1. Large area Germanium Tin nanometer optical film coatings on highly flexible aluminum substrates.

    PubMed

    Jin, Lichuan; Zhang, Dainan; Zhang, Huaiwu; Fang, Jue; Liao, Yulong; Zhou, Tingchuan; Liu, Cheng; Zhong, Zhiyong; Harris, Vincent G

    2016-09-26

    Germanium Tin (GeSn) films have drawn great interest for their visible and near-infrared optoelectronics properties. Here, we demonstrate large area Germanium Tin nanometer thin films grown on highly flexible aluminum foil substrates using low-temperature molecular beam epitaxy (MBE). Ultra-thin (10-180 nm) GeSn film-coated aluminum foils display a wide color spectra with an absorption wavelength ranging from 400-1800 nm due to its strong optical interference effect. The light absorption ratio for nanometer GeSn/Al foil heterostructures can be enhanced up to 85%. Moreover, the structure exhibits excellent mechanical flexibility and can be cut or bent into many shapes, which facilitates a wide range of flexible photonics. Micro-Raman studies reveal a large tensile strain change with GeSn thickness, which arises from lattice deformations. In particular, nano-sized Sn-enriched GeSn dots appeared in the GeSn coatings that had a thickness greater than 50 nm, which induced an additional light absorption depression around 13.89 μm wavelength. These findings are promising for practical flexible photovoltaic and photodetector applications ranging from the visible to near-infrared wavelengths.

  2. High-order Harmonic Generation in Ultra Thin Plasma Foil

    NASA Astrophysics Data System (ADS)

    Shuai, Bin; Shen, Baifei; Li, Ruxin; Xu, Zhizhan

    Via l-D Particle In Cell (PIC) simulations, we investigated the high-order harmonic emission from flim plasma foils irradiated by two circular- polarized, counter-propagating laser pulses with their electrical vectors rotating in different directions. More than 200 harmonics can be generated with a laser intensity of 1021 W/cm2. When the duration of laser gets shorter, the frequencies of harmonics were severely modulated due to the Doppler shift caused by the movement of the plasma boundary when the foil is being compressed. The Doppler shift can be estimated by the simulation results, and this effect can also be reduced or modified by introducing frequency chirping to the pump pulse.

  3. μ-Foil Polymer Electrode Array for Intracortical Neural Recordings.

    PubMed

    Ejserholm, Fredrik; Köhler, Per; Granmo, Marcus; Schouenborg, Jens; Bengtsson, Martin; Wallman, Lars

    2014-01-01

    We have developed a multichannel electrode array-termed [Formula: see text]-foil-that comprises ultrathin and flexible electrodes protruding from a thin foil at fixed distances. In addition to allowing some of the active sites to reach less compromised tissue, the barb-like protrusions that also serves the purpose of anchoring the electrode array into the tissue. This paper is an early evaluation of technical aspects and performance of this electrode array in acute in vitro/in vivo experiments. The interface impedance was reduced by up to two decades by electroplating the active sites with platinum black. The platinum black also allowed for a reduced phase lag for higher frequency components. The distance between the protrusions of the electrode array was tailored to match the architecture of the rat cerebral cortex. In vivo acute measurements confirmed a high signal-to-noise ratio for the neural recordings, and no significant crosstalk between recording channels.

  4. Plasma flow switch and foil implosion experiments on Pegasus II

    SciTech Connect

    Cochrane, J.C.; Bartsch, R.R.; Benage, J.R.; Forman, P.R.; Gribble, R.F.; Ladish, J.S.; Oona, H.; Parker, J.V.; Scudder, D.W.; Shlachter, J.S.; Wysocki, F.J.

    1993-07-01

    Pegasus II is the upgraded version of Pegasus, a pulsed power machine used in the Los Alamos AGEX (Above Ground EXperiments) program. A goal of the program is to produce an intense (> 100 TW) source of soft x-rays from the thermalization of the kinetic energy of a 1 to 10 MJ plasma implosion. The radiation pulse should have a maximum duration of several 10`s of nanoseconds and will be used in the study of fusion conditions and material properties. The radiating plasma source will be generated by the thermalization of the kinetic energy of an imploding cylindrical, thin, metallic foil. This paper addresses experiments done on a capacitor bank to develop a switch (plasma flow switch) to switch the bank current into the load at peak current. This allows efficient coupling of bank energy into foil kinetic energy.

  5. Plasma flow switch and foil implosion experiments on Pegasus II

    SciTech Connect

    Cochrane, J.C.; Bartsch, R.R.; Benage, J.R.; Forman, P.R.; Gribble, R.F.; Ladish, J.S.; Oona, H.; Parker, J.V.; Scudder, D.W.; Shlachter, J.S.; Wysocki, F.J.

    1993-01-01

    Pegasus II is the upgraded version of Pegasus, a pulsed power machine used in the Los Alamos AGEX (Above Ground EXperiments) program. A goal of the program is to produce an intense (> 100 TW) source of soft x-rays from the thermalization of the kinetic energy of a 1 to 10 MJ plasma implosion. The radiation pulse should have a maximum duration of several 10's of nanoseconds and will be used in the study of fusion conditions and material properties. The radiating plasma source will be generated by the thermalization of the kinetic energy of an imploding cylindrical, thin, metallic foil. This paper addresses experiments done on a capacitor bank to develop a switch (plasma flow switch) to switch the bank current into the load at peak current. This allows efficient coupling of bank energy into foil kinetic energy.

  6. Gas Foil Bearing Technology Advancements for Closed Brayton Cycle Turbines

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.; Bruckner, Robert J.; DellaCorte, Christopher; Radil, Kevin C.

    2007-01-01

    Closed Brayton Cycle (CBC) turbine systems are under consideration for future space electric power generation. CBC turbines convert thermal energy from a nuclear reactor, or other heat source, to electrical power using a closed-loop cycle. The operating fluid in the closed-loop is commonly a high pressure inert gas mixture that cannot tolerate contamination. One source of potential contamination in a system such as this is the lubricant used in the turbomachine bearings. Gas Foil Bearings (GFB) represent a bearing technology that eliminates the possibility of contamination by using the working fluid as the lubricant. Thus, foil bearings are well suited to application in space power CBC turbine systems. NASA Glenn Research Center is actively researching GFB technology for use in these CBC power turbines. A power loss model has been developed, and the effects of a very high ambient pressure, start-up torque, and misalignment, have been observed and are reported here.

  7. Fine plastic foil as backing for sputtered nickel targets.

    PubMed

    Stolarz, Anna; Seppälä, Raimo

    Targets of (58)Ni and (60)Ni with areal density between 71 and 105 μg/cm(2) backed with polyimide foil of 35-40 μg/cm(2) were prepared by sputtering with Ar ions produced by a home made sputtering device at the Target Laboratory, University of Jyväskylä. The efficiency of the procedure was about 20 %.

  8. Hot Rolling of Gamma Titanium Aluminide Foil (PREPRINT)

    DTIC Science & Technology

    2010-04-01

    the flow stress as a function of strain rate , the strength coefficient for the specific phase i, 10 and the strain - rate sensitivity (assumed to...extended to the case of rate - sensitive , incompressible materials by Suquet [14]. Subsequently, it was applied to conventional titanium alloys by...AFRL-RX-WP-TP-2010-4138 HOT ROLLING OF GAMMA TITANIUM ALUMINIDE FOIL (PREPRINT) S.L. Semiatin Metals Branch Metals, Ceramics & NDE

  9. Pyrophoric Nanoparticles and Nanoporous Foils for Defense Applications

    DTIC Science & Technology

    2008-12-01

    1 PYROPHORIC NANOPARTICLES AND NANOPOROUS FOILS FOR DEFENSE APPLICATIONS Rajesh Shende , Zac Doorenbos, Alok Vats, and Jan Puszynski* South...metal and method or preparing, US Patent 4895609, January 2, 1990. [13] Shende , R.V., Vats, A., Doorenbos, Z. D., Kapoor, D., Martin, D...Chemical Propulsion, Kyoto, Japan, Sep. 17-21 (to be published). [14] Shende , R.V., Vats, A., Doorenbos, Z. D., Kapoor, D., Haines, C., Martin, D

  10. Procyon experiments utilizing foil-fuse opening switches

    SciTech Connect

    Rickel, D.G.; Lindemuth, I.R.; Reinovsky, R.E.; Brownell, J.H.; Goforth, J.H.; Greene, A.E.; Kruse, H.W.; Oona, H.; Parker, J.V.; Turchi, P.J.

    1991-01-01

    The Los Alamos National Laboratory has applied the explosive magnetic flux compression generator (FCG) technology to the high-energy foil-implosion project, Trailmaster, to reach energy levels unattainable by other methods under current budget constraints. A required component for FCG systems is a power-conditioning stage that matches the slow risetime of the energy source with the fast-risetime requirements of the foil-implosion load. Currently, the Trailmaster concept is based on a two-step process of combining an intermediate power compression stage with a plasma flow switch (PFS) that will deliver energy to an imploding foil on the order of 100 ns. The intermediate power compression stage, which is the main emphasis of this report, consists of an energy storage inductor loaded by the FCG (the energy sauce) and an associated opening and closing switch. In our Procyon testing series, a subtask of the Trailmaster project, we have explored two approaches for opening and closing switches. One uses an explosive opening switch (EFF) and a detonator-initiated closing switch, the topic of another paper at this conference, and the other a resistive fuse opening switch a surface tracking closing switch (STS), the subject of this presentation. This latter concept was successfully tested last summer with a complete plasma flow switch assembly except the dynamic implosion foil was replaced by a rigid passive inductive load. We present data on the performance of the fuse opening switch, the surface tracking closing switch, and the plasma flow switch. 7 refs., 9 figs.

  11. Nickel foil microcantilevers for magnetic manipulation and localized heating.

    PubMed

    Gaitas, Angelo; McNaughton, Brandon H

    2013-12-01

    Cellular manipulation has been investigated by a number of techniques. In this manuscript nickel foil microcantilevers were used for magnetophoresis and manipulation of microparticles and magnetically labeled HeLa cells. The cantilevers were also used for localized heating in liquid, reaching biologically relevant temperatures. This work aims to develop cantilevers for sample enrichment, manipulation, and thermal applications, offering an inexpensive and versatile solution compatible with standard tools in research and clinical diagnostic testing, such as microwell plates.

  12. Nickel foil microcantilevers for magnetic manipulation and localized heating

    PubMed Central

    Gaitas, Angelo; McNaughton, Brandon H.

    2014-01-01

    Cellular manipulation has been investigated by a number of techniques. In this manuscript nickel foil microcantilevers were used for magnetophoresis and manipulation of microparticles and magnetically labeled HeLa cells. The cantilevers were also used for localized heating in liquid, reaching biologically relevant temperatures. This work aims to develop cantilevers for sample enrichment, manipulation, and thermal applications, offering an inexpensive and versatile solution compatible with standard tools in research and clinical diagnostic testing, such as microwell plates. PMID:25541581

  13. Regeneration of aluminum hydride

    DOEpatents

    Graetz, Jason Allan; Reilly, James J; Wegrzyn, James E

    2012-09-18

    The present invention provides methods and materials for the formation of hydrogen storage alanes, AlH.sub.x, where x is greater than 0 and less than or equal to 6 at reduced H.sub.2 pressures and temperatures. The methods rely upon reduction of the change in free energy of the reaction between aluminum and molecular H.sub.2. The change in free energy is reduced by lowering the entropy change during the reaction by providing aluminum in a state of high entropy, and by increasing the magnitude of the change in enthalpy of the reaction or combinations thereof.

  14. Regeneration of aluminum hydride

    DOEpatents

    Graetz, Jason Allan; Reilly, James J.

    2009-04-21

    The present invention provides methods and materials for the formation of hydrogen storage alanes, AlH.sub.x, where x is greater than 0 and less than or equal to 6 at reduced H.sub.2 pressures and temperatures. The methods rely upon reduction of the change in free energy of the reaction between aluminum and molecular H.sub.2. The change in free energy is reduced by lowering the entropy change during the reaction by providing aluminum in a state of high entropy, by increasing the magnitude of the change in enthalpy of the reaction or combinations thereof.

  15. DEVELOPMENT OF MANUFACTURING METHODS FOR LIGHTWEIGHT METAL FOIL HEAT EXCHANGERS.

    DTIC Science & Technology

    MICROSTRUCTURE, TENSILE PROPERTIES, STRESSES, SPOT WELDS, COATINGS , SILICIDES , OXIDATION, TEST METHODS....PHOSPHORUS ALLOYS, ALUMINUM ALLOYS, NIOBIUM ALLOYS, PRESSURE, THERMAL JOINING, AEROSPACE CRAFT, DIFFUSION, BONDING, VACUUM FURNACES, SOLDERED JOINTS

  16. The investigation of electrolytic surface roughening for PCB copper foil

    NASA Astrophysics Data System (ADS)

    Lee, Shuo-Jen; Liu, Chao-Kai

    2013-10-01

    This study is the application of the principle of electrochemical. The anodic dissolution has no concentration polarization. Hence, electrolyte life is substantially increased. The waste copper is high in ion concentration with a recovery value. As compared with the current PCB chemical pre-treatment method, it may have advantages of cost-saving, improvement of overall efficiency, reduction of production costs and reduction of the amount of waste generated. In the development of the copper foil for electrochemical roughening process, the use of electrolysis reaction affects the copper surface dissolution to form a unique bump coarsening. It will increase in the surface area of the copper foil to improve dry film solder mask and the adhesion between the copper surfaces. Four electrolytes, two neutral salts and two acids, were selected to explore the best of the electrolytic roughening parameters of temperature, time and voltage. The surface roughness and the surface morphology of the copper foil were measured before and after the electrolytic surface roughening. Finally, after repeated experiments, electrolytes A and B copper generates obvious inter-granular corrosion, resulting in a rough surface similar to the chemical pre-treatment. On the other hands, the surface morphology resulted from electrolytes C and D appears more like pitting. Both electrolytic could generate surface roughness of Ra 0.3 um roughened copper surface higher than industrial standard.

  17. Density Profile of a Foil Accelerated by Laser Ablation

    NASA Astrophysics Data System (ADS)

    Knauer, J. P.; Hu, S. X.; Goncharov, V. N.; Haberberger, D.

    2016-10-01

    An experiment to measure the density profile of a foil accelerated by laser ablation has been designed and is underway. High-density material is measured with x-ray radiography and low-density plasma is measured using 251-nm interferometry. Two-dimensional hydrodynamic simulation results from the code DRACO will be compared to these data. The accelerated foil is an 80- μm-thick CH target with Ge and Si-doped layers. The incident laser is a 351-nm, 5-ns pulse with a total energy of 6.2 kJ. Si and Ti x rays are used for the radiography measurement. A 1-D image versus time data are recorded with an x-ray streak camera and 2-D image data at specific times are recorded with an x-ray framing camera using point-projection backlighting. Foil acceleration is measured with the 1-D data. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  18. Fission foil detector calibrations with high energy protons

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.

    1995-01-01

    Fission foil detectors (FFD's) are passive devices composed of heavy metal foils in contact with muscovite mica films. The heavy metal nuclei have significant cross sections for fission when irradiated with neutrons and protons. Each isotope is characterized by threshold energies for the fission reactions and particular energy-dependent cross sections. In the FFD's, fission fragments produced by the reactions are emitted from the foils and create latent particle tracks in the adjacent mica films. When the films are processed surface tracks are formed which can be optically counted. The track densities are indications of the fluences and spectra of neutrons and/or protons. In the past, detection efficiencies have been calculated using the low energy neutron calibrated dosimeters and published fission cross sections for neutrons and protons. The problem is that the addition of a large kinetic energy to the (n,nucleus) or (p,nucleus) reaction could increase the energies and ranges of emitted fission fragments and increase the detector sensitivity as compared with lower energy neutron calibrations. High energy calibrations are the only method of resolving the uncertainties in detector efficiencies. At high energies, either proton or neutron calibrations are sufficient since the cross section data show that the proton and neutron fission cross sections are approximately equal. High energy proton beams have been utilized (1.8 and 4.9 GeV, 80 and 140 MeV) for measuring the tracks of fission fragments emitted backward and forward.

  19. Fission foil detector calibrations with high energy protons

    SciTech Connect

    Benton, E.V.; Frank, A.L.

    1995-03-01

    Fission foil detectors (FFD`s) are passive devices composed of heavy metal foils in contact with muscovite mica films. The heavy metal nuclei have significant cross sections for fission when irradiated with neutrons and protons. Each isotope is characterized by threshold energies for the fission reactions and particular energy-dependent cross sections. In the FFD`s, fission fragments produced by the reactions are emitted from the foils and create latent particle tracks in the adjacent mica films. When the films are processed surface tracks are formed which can be optically counted. The track densities are indications of the fluences and spectra of neutrons and/or protons. In the past, detection efficiencies have been calculated using the low energy neutron calibrated dosimeters and published fission cross sections for neutrons and protons. The problem is that the addition of a large kinetic energy to the (n,nucleus) or (p,nucleus) reaction could increase the energies and ranges of emitted fission fragments and increase the detector sensitivity as compared with lower energy neutron calibrations. High energy calibrations are the only method of resolving the uncertainties in detector efficiencies. At high energies, either proton or neutron calibrations are sufficient since the cross section data show that the proton and neutron fission cross sections are approximately equal. High energy proton beams have been utilized (1.8 and 4.9 GeV, 80 and 140 MeV) for measuring the tracks of fission fragments emitted backward and forward.

  20. Flapping propulsion with side-by-side pitching foils

    NASA Astrophysics Data System (ADS)

    Huera-Huarte, Francisco

    2016-11-01

    Fish schools are one of the most common types of collective behaviour observed in nature. One of the reasons why fish swim in groups, is to reduce the cost of transport of the school. In this work we explore the propulsive performance of two foils flapping in a symmetric configuration, i.e. with an out-of-phase flapping motion. Direct thrust measurements and Particle Image Velocimetry (PIV) allowed a detailed examination of the forces and the wake generated by the system, for different kinematics (swept angles and frequencies) and shaft separations. For certain specific cases, volumetric PIV shows major differences on how the different structures in the wake of the system evolve, depending on the imposed kinematics and the side-by-side separation between the foils. Results obtained will be compared against data produced with isolated flapping foils with similar imposed kinematics, with the aim to better understand the interactions between both and the performance of the system as a whole. The author would like to acknowledge the financial support provided by the Spanish Ministerio de Economia y competitividad (MINECO) through Grant DPI2015-71645-P.

  1. Comparison of EXAFS Foil Spectra from Around the World

    SciTech Connect

    Kelly, S. D.; Bare, S. R.; Greenlay, N.; Azevedo, G.; Balasubramanian, M.; Barton, D.; Chattopadhyay, S.; Fakra, S.; Johannessen, B.; Newville, M.; Pena, J.; Pokrovski, G. S; Proux, O.; Priolkar, K.; Ravel, B.; Webb, S. M.

    2010-07-16

    The EXAFS spectra of Cu and Pd foil from many different beamlines and synchrotrons are compared to address the dependence of the amplitude reduction factor (S{sub 0}{sup 2}) on beamline specific parameters. Even though S{sub 0}{sup 2} is the same parameter as the EXAFS coordination number, the value for S{sub 0}{sup 2} is given little attention, and is often unreported. The S{sub 0}{sup 2} often differs for the same material due to beamline and sample attributes, such that no importance is given to S{sub 0}{sup 2}-values within a general range of 0.7 to 1.1. EXAFS beamlines have evolved such that it should now be feasible to use standard S{sub 0}{sup 2} values for all EXAFS measurements of a specific elemental environment. This would allow for the determination of the imaginary energy (Ei) to account for broadening of the EXAFS signal rather than folding these errors into an effective S{sub 0}{sup 2}-value. To test this concept, we model 11 Cu-foil and 6 Pd-foil EXAFS spectra from around the world to compare the difference in S{sub 0}{sup 2}- and Ei-values.

  2. PROCESS FOR REMOVING ALUMINUM COATINGS

    DOEpatents

    Flox, J.

    1959-07-01

    A process is presented for removing aluminum jackets or cans from uranium slugs. This is accomplished by immersing the aluminum coated uranium slugs in an aqueous solution of 9 to 20% sodium hydroxide and 35 to 12% sodium nitrate to selectively dissolve the aluminum coating, the amount of solution being such as to obtain a molar ratio of sodium hydroxide to aluminum of at least

  3. Electrically conductive anodized aluminum coatings

    NASA Technical Reports Server (NTRS)

    Alwitt, Robert S. (Inventor); Liu, Yanming (Inventor)

    2001-01-01

    A process for producing anodized aluminum with enhanced electrical conductivity, comprising anodic oxidation of aluminum alloy substrate, electrolytic deposition of a small amount of metal into the pores of the anodized aluminum, and electrolytic anodic deposition of an electrically conductive oxide, including manganese dioxide, into the pores containing the metal deposit; and the product produced by the process.

  4. REMOVAL OF ALUMINUM COATINGS

    DOEpatents

    Peterson, J.H.

    1959-08-25

    A process is presented for dissolving aluminum jackets from uranium fuel elements without attack of the uranium in a boiling nitric acid-mercuric nitrate solution containing up to 50% by weight of nitrtc acid and mercuric nitrate in a concentration of between 0.05 and 1% by weight.

  5. Markets for recovered aluminum

    SciTech Connect

    Not Available

    1993-04-01

    The study describes the operation of the markets for scrap aluminum as an example of how recycling markets are structured, what factors influence the supply of and demand for materials, what projections can be made about recycling markets, and how government policies to increase recycling may affect these markets.

  6. Building an aluminum car

    SciTech Connect

    Ashley, S.

    1994-05-01

    This article examines the increasing use of aluminum in automobiles to decrease weight and consequently increase fuel economy. The topics of the article include federal fuel economy goals, the development of optimum body structure and manufacturing techniques, comparison with steel, cost of materials, weight reduction and recycling of materials.

  7. Fluxless aluminum brazing

    DOEpatents

    Werner, W.J.

    1974-01-01

    This invention relates to a fluxless brazing alloy for use in forming brazed composites made from members of aluminum and its alloys. The brazing alloy consists of 35-55% Al, 10--20% Si, 25-60% Ge; 65-88% Al, 2-20% Si, 2--18% In; 65--80% Al, 15-- 25% Si, 5- 15% Y. (0fficial Gazette)

  8. Aluminum battery alloys

    DOEpatents

    Thompson, David S.; Scott, Darwin H.

    1985-01-01

    Aluminum alloys suitable for use as anode structures in electrochemical cs are disclosed. These alloys include iron levels higher than previously felt possible, due to the presence of controlled amounts of manganese, with possible additions of magnesium and controlled amounts of gallium.

  9. Aluminum battery alloys

    DOEpatents

    Thompson, D.S.; Scott, D.H.

    1984-09-28

    Aluminum alloys suitable for use as anode structures in electrochemical cells are disclosed. These alloys include iron levels higher than previously felt possible, due to the presence of controlled amounts of manganese, with possible additions of magnesium and controlled amounts of gallium.

  10. Aluminum Sulfate 18 Hydrate

    ERIC Educational Resources Information Center

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) of the chemical, aluminum sulfate 18 hydrate, is presented. The profile lists physical and harmful properties, exposure limits, reactivity risks, and symptoms of major exposure for the benefit of teachers and students using the chemical in the laboratory.

  11. Bonding aluminum beam leads

    NASA Technical Reports Server (NTRS)

    Burkett, F. S.

    1978-01-01

    Report makes it relatively easy for hybrid-circuit manufacturers to convert integrated circuit chips with aluminum bead leads. Report covers: techniques for handling tiny chips; proper geometries for ultrasonic bonding tips; best combinations of pressure, pulse time, and ultrasonic energy for bonding; and best thickness for metal films to which beam leads are bonded.

  12. The oxidation of aluminum at high temperature studied by Thermogravimetric Analysis and Differential Scanning Calorimetry.

    SciTech Connect

    Coker, Eric Nicholas

    2013-10-01

    The oxidation in air of high-purity Al foil was studied as a function of temperature using Thermogravimetric Analysis with Differential Scanning Calorimetry (TGA/DSC). The rate and/or extent of oxidation was found to be a non-linear function of the temperature. Between 650 and 750 ÀC very little oxidation took place; at 850 ÀC oxidation occurred after an induction period, while at 950 ÀC oxidation occurred without an induction period. At oxidation temperatures between 1050 and 1150 ÀC rapid passivation of the surface of the aluminum foil occurred, while at 1250 ÀC and above, an initial rapid mass increase was observed, followed by a more gradual increase in mass. The initial rapid increase was accompanied by a significant exotherm. Cross-sections of oxidized specimens were characterized by scanning electron microscopy (SEM); the observed alumina skin thicknesses correlated qualitatively with the observed mass increases.

  13. SOLDERING OF ALUMINUM BASE METALS

    DOEpatents

    Erickson, G.F.

    1958-02-25

    This patent deals with the soldering of aluminum to metals of different types, such as copper, brass, and iron. This is accomplished by heating the aluminum metal to be soldered to slightly above 30 deg C, rubbing a small amount of metallic gallium into the part of the surface to be soldered, whereby an aluminum--gallium alloy forms on the surface, and then heating the aluminum piece to the melting point of lead--tin soft solder, applying lead--tin soft solder to this alloyed surface, and combining the aluminum with the other metal to which it is to be soldered.

  14. Measurement of the radon diffusion through a nylon foil for different air humidities

    SciTech Connect

    Mamedov, Fadahat; Štekl, Ivan; Smolek, Karel

    2015-08-17

    The dependency of the radon penetration through a nylon foil on air humidity was measured. Such information is needed for the tracking part of the SuperNEMO detector, which is planned to be shielded against radon by nylon foil and in which the air humidity is not negligible. The long term measurements of radon penetration through nylon foils for different air humidities were performed with the radon diffusion setup constructed at the IEAP, CTU in Prague. The setup consists of two stainless steel hemispheres with Si detector in each of them. Both hemispheres are separated by the tested foil. While the left hemisphere contains high Rn activity, the right part contains only activity caused by the radon penetration through the tested foil. Obtained results of this study with a nylon foil with the thickness of 50 µm are presented.

  15. Beam Loss due to Foil Scattering in the SNS Accumulator Ring

    SciTech Connect

    Holmes, Jeffrey A; Plum, Michael A

    2012-01-01

    In order to better understand the contribution of scattering from the primary stripper foil to losses in the SNS ring, we have carried out calculations using the ORBIT Code aimed at evaluating these losses. These calculations indicate that the probability of beam loss within one turn following a foil hit is ~1.8 10-8 , where is the foil thickness in g/cm2, assuming a carbon foil. Thus, for a typical SNS stripper foil of thickness = 390 g/cm2, the probability of loss within one turn of a foil hit is ~7.0 10-6. This note describes the calculations used to arrive at this result, presents the distribution of these losses around the SNS ring, and compares the calculated results with observed ring losses for a well-tuned production beam.

  16. Measurement of the radon diffusion through a nylon foil for different air humidities

    NASA Astrophysics Data System (ADS)

    Mamedov, Fadahat; Štekl, Ivan; Smolek, Karel

    2015-08-01

    The dependency of the radon penetration through a nylon foil on air humidity was measured. Such information is needed for the tracking part of the SuperNEMO detector, which is planned to be shielded against radon by nylon foil and in which the air humidity is not negligible. The long term measurements of radon penetration through nylon foils for different air humidities were performed with the radon diffusion setup constructed at the IEAP, CTU in Prague. The setup consists of two stainless steel hemispheres with Si detector in each of them. Both hemispheres are separated by the tested foil. While the left hemisphere contains high Rn activity, the right part contains only activity caused by the radon penetration through the tested foil. Obtained results of this study with a nylon foil with the thickness of 50 µm are presented.

  17. Pu-ZR Alloy high-temperature activation-measurement foil

    DOEpatents

    McCuaig, Franklin D.

    1977-08-02

    A nuclear reactor fuel alloy consists essentially of from slightly greater than 7 to about 4 w/o zirconium, balance plutonium, and is characterized in that the alloy is castable and is rollable to thin foils. A preferred embodiment of about 7 w/o zirconium, balance plutonium, has a melting point substantially above the melting point of plutonium, is rollable to foils as thin as 0.0005 inch thick, and is compatible with cladding material when repeatedly cycled to temperatures above 650.degree. C. Neutron flux densities across a reactor core can be determined with a high-temperature activation-measurement foil which consists of a fuel alloy foil core sandwiched and sealed between two cladding material jackets, the fuel alloy foil core being a 7 w/o zirconium, plutonium foil which is from 0.005 to 0.0005 inch thick.

  18. Pu-Zr alloy for high-temperature foil-type fuel

    DOEpatents

    McCuaig, Franklin D.

    1977-01-01

    A nuclear reactor fuel alloy consists essentially of from slightly greater than 7 to about 4 w/o zirconium, balance plutonium, and is characterized in that the alloy is castable and is rollable to thin foils. A preferred embodiment of about 7 w/o zirconium, balance plutonium, has a melting point substantially above the melting point of plutonium, is rollable to foils as thin as 0.0005 inch thick, and is compatible with cladding material when repeatedly cycled to temperatures above 650.degree. C. Neutron reflux densities across a reactor core can be determined with a high-temperature activation-measurement foil which consists of a fuel alloy foil core sandwiched and sealed between two cladding material jackets, the fuel alloy foil core being a 7 w/o zirconium, plutonium foil which is from 0.005 to 0.0005 inch thick.

  19. Ultrasonic Additive Manufacturing: Weld Optimization for Aluminum 6061, Development of Scarf Joints for Aluminum Sheet Metal, and Joining of High Strength Metals

    NASA Astrophysics Data System (ADS)

    Wolcott, Paul J.

    Ultrasonic additive manufacturing (UAM) is a low temperature, solid-state manufacturing process that enables the creation of layered, solid metal structures with designed anisotropies and embedded materials. As a low temperature process, UAM enables the creation of active composites containing smart materials, components with embedded sensors, thermal management devices, and many others. The focus of this work is on the improvement and characterization of UAM aluminum structures, advancing the capabilities of ultrasonic joining into sheet geometries, and examination of dissimilar material joints using the technology. Optimized process parameters for Al 6061 were identified via a design of experiments study indicating a weld amplitude of 32.8 synum and a weld speed of 200 in/min as optimal. Weld force and temperature were not significant within the levels studied. A methodology of creating large scale builds is proposed, including a prescribed random stacking sequence and overlap of 0.0035 in. (0.0889 mm) for foils to minimize voids and maximize mechanical strength. Utilization of heat treatments is shown to significantly increase mechanical properties of UAM builds, within 90% of bulk material. The applied loads during the UAM process were investigated to determine the stress fields and plastic deformation induced during the process. Modeling of the contact mechanics via Hertzian contact equations shows that significant stress is applied via sonotrode contact in the process. Contact modeling using finite element analysis (FEA), including plasticity, indicates that 5000 N normal loads result in plastic deformation in bulk aluminum foil, while at 3000 N no plastic deformation occurs. FEA studies on the applied loads during the process, specifically a 3000 N normal force and 2000 N shear force, show that high stresses and plastic deformation occur at the edges of a welded foil, and base of the UAM build. Microstructural investigations of heat treated foils confirms

  20. A Monte Carlo studies of the entrance foil material in a target assembly for FDG production

    SciTech Connect

    Merouani, A.; El Khayati, N.; EL Ghayour, A.; El Alamy, H.; Zoubir, B.

    2015-07-01

    In this work, a Monte Carlo simulation was performed for different entrance foil Materials in the target assembly for [{sup 18}F] FDG production, to investigate the neutron generations in the entrance foil. However, the objective is to study a materials that has the more or less similar mechanical properties as the Havar{sup R} foil with less generation of secondary particles and without affecting, the yield of FDG production. (authors)

  1. Multilayer reactive foils: Fabrication, reaction characterization, and room-temperature joining

    NASA Astrophysics Data System (ADS)

    Reiss, Michael Eric

    The self-propagating reactive multilayer foils studied here were composed of alternating nanoscale layers of Al and Ni. The reactions associated with these foils can reach temperatures well over 1600°C with propagation velocities one the order of 1 to 10 m/s. In order to characterized these reactions, a high spatial resolution (50 micron), high temporal resolution (25 microsecond) and high temperature resolution ratio pyrometer with a range of 900°C to 2000°C, was designed and assembled. The pyrometer was optimized for use with the self-propagating reactive foil systems and was used in conjunction with an apparatus for measuring the propagation velocity of these reactive foils. The custom velocity and temperature devices were used to analyze the interrelationships between reaction velocity, maximum temperature, and activation energy in the Al-Ni reactive foil system. The results of this study indicate that final temperature and layer thickness may have opposing influences on reaction rate. The process of joining SiC to Ti-6-4 was investigated from the standpoint of using reactive foils as an in-situ heat source. Advances in reactive foil deposition techniques were made to facilitate the fabrication of thick foils (>100 micron). Room temperature reactive foil joining with no external heat source was demonstrated and preliminary studies on the substantial bond strength were performed. Finally, an investigation into the feasibility of fabricating reactive foils from layers of metal sheet was performed. The combined techniques of swaging and rolling were shown to be a promising method for the scale-up of reactive foil production, and reactive foils with properties similar to those of vapor deposited materials were be obtained via this process.

  2. Large-area monolayer hexagonal boron nitride on Pt foil.

    PubMed

    Park, Ji-Hoon; Park, Jin Cheol; Yun, Seok Joon; Kim, Hyun; Luong, Dinh Hoa; Kim, Soo Min; Choi, Soo Ho; Yang, Woochul; Kong, Jing; Kim, Ki Kang; Lee, Young Hee

    2014-08-26

    Hexagonal boron nitride (h-BN) has recently been in the spotlight due to its numerous applications including its being an ideal substrate for two-dimensional electronics, a tunneling material for vertical tunneling devices, and a growth template for heterostructures. However, to obtain a large area of h-BN film while maintaining uniform thickness is still challenging and has not been realized. Here, we report the systematical study of h-BN growth on Pt foil by using low pressure chemical vapor deposition with a borazine source. The monolayer h-BN film was obtained over the whole Pt foil (2 × 5 cm(2)) under <100 mTorr, where the size is limited only by the Pt foil size. A borazine source was catalytically decomposed on the Pt surface, leading to the self-limiting growth of the monolayer without the associating precipitation, which is very similar to the growth of graphene on Cu. The orientation of the h-BN domains was largely confined by the Pt domain, which is confirmed by polarizing optical microscopy (POM) assisted by the nematic liquid crystal (LC) film. The total pressure and orientation of the Pt lattice plane are crucial parameters for thickness control. At high pressure (∼0.5 Torr), thick film was grown on Pt (111), and in contrast, thin film was grown on Pt (001). Our advances in monolayer h-BN growth will play an important role to further develop a high quality h-BN film that can be used for vertical tunneling, optoelectronic devices and growth templates for a variety of heterostructures.

  3. Analysis of cartilage-polydioxanone foil composite grafts.

    PubMed

    Kim, James H; Wong, Brian

    2013-12-01

    This study presents an analytical investigation into the mechanical behavior of a cartilage-polydioxanone (PDS) plate composite grafts. Numerical methods are used to provide a first-order, numerical model of the flexural stiffness of a cartilage-PDS graft. Flexural stiffness is a measure of resistance to bending and is inversely related to the amount of deformation a structure may experience when subjected to bending forces. The cartilage-PDS graft was modeled as a single composite beam. Using Bernoulli-Euler beam theory, a closed form equation for the theoretical flexural stiffness of the composite graft was developed. A parametric analysis was performed to see how the flexural properties of the composite model changed with varying thicknesses of PDS foil. The stiffness of the cartilage-PDS composite using 0.15-mm-thick PDS was four times higher than cartilage alone. The composite with a 0.5-mm-thick PDS graft was only 1.7 times stiffer than the composite with the 0.15-mm-thick PDS graft. Although a thicker graft material will yield higher flexural stiffness for the composite, the relationship between composite stiffness and PDS thickness is nonlinear. After a critical point, increments in graft thickness produce gradually smaller improvements in flexural stiffness. The small increase in stiffness when using the thicker PDS foils versus the 0.15 mm PDS foil may not be worth the potential complications (prolonged foreign body reaction, reduction in nutrient diffusion to cartilage) of using thicker artificial grafts.

  4. Polycarbosilazane passivation on graphite foil used as gasket seal

    NASA Astrophysics Data System (ADS)

    Prette, A. L. G.; Haage, T.; Will, A.; Kolb, M.; Flores, O.; Günthner, M.; Motz, G.

    2013-12-01

    Gasket seals are often used in industry and laboratories where a leak-proof installation is needed in order to avoid loss of products or dangerous materials. Many of products transported inside tubes are at relatively high temperatures excluding polymeric gaskets. In the same line, many of transported materials contain solvents which can attack polymer sealings, therefore limiting their use. An alternative is to use graphite joints as sealings. These joints are a sandwich of graphite foil and stainless steel mesh as forming core. The problem that raises using graphite in contact with steel is that at temperatures of about 500 °C an interdiffusion of carbon on the steel structure occurs which produces adhesion of the graphite gasket on the metallic flange. Therefore this adhesion increases the time to change each gasket, since rests of previously adhered graphite has to be removed from the flange. In order to avoid the adhesion of the graphite on the flange, polycarbosilazane precursor was used as protective finishing on the graphite foil surface. After thermal transformation of the polymer into the corresponding PDC finishing, it acts in two manners: It avoids the direct contact between the carbon and the steel and it allows the sealing of liquids and gases. Adhesion tests were done and showed that the foils passivated with PDCs did not adhere to the steel flange. Moreover, the production methods and products are compatible to industrial environment and processes. The results found here show that the time to change the gasket in industry can be clearly reduced by using the PDC finishing on graphite gasket.

  5. Foil system fatigue load environments for commercial hydrofoil operation

    NASA Technical Reports Server (NTRS)

    Graves, D. L.

    1979-01-01

    The hydrofoil fatigue loads environment in the open sea is examined. The random nature of wave orbital velocities, periods and heights plus boat heading, speed and control system design are considered in the assessment of structural fatigue requirements. Major nonlinear load events such as hull slamming and foil unwetting are included in the fatigue environment. Full scale rough water load tests, field experience plus analytical loads work on the model 929 Jetfoil commercial hydrofoil are discussed. The problem of developing an overall sea environment for design is defined. State of the art analytical approaches are examined.

  6. Critical mass experiment using U-235 foils and lucite plates

    SciTech Connect

    Sanchez, R.; Butterfield, K.; Kimpland, R.; Jaegers, P.

    1998-05-01

    The main objective of this experiment was to show how the multiplication of the system increases as moderated material is placed between highly enriched uranium foils. In addition, this experiment served to demonstrate the hand-stacking techniques, and approach to criticality by remote operation. This experiment was designed by Tom McLaughlin in the mid seventies as part of the criticality safety course that is taught at Los Alamos Critical Experiment Facility (LACEF). The W-U-235 ratio for this experiment was 215 which is where the minimum critical mass for this configuration occurs.

  7. Prediction of Gas Lubricated Foil Journal Bearing Performance

    NASA Technical Reports Server (NTRS)

    Carpino, Marc; Talmage, Gita

    2003-01-01

    This report summarizes the progress in the first eight months of the project. The objectives of this research project are to theoretically predict the steady operating conditions and the rotor dynamic coefficients of gas foil journal bearings. The project is currently on or ahead of schedule with the development of a finite element code that predicts steady bearing performance characteristics such as film thickness, pressure, load, and drag. Graphical results for a typical bearing are presented in the report. Project plans for the next year are discussed.

  8. Gas Lubricated Foil Bearing Development for Advanced Turbomachines

    DTIC Science & Technology

    1977-03-01

    THIS PAGE (Alh.n )•af. Entered) REPOR DO T PAGE READ INSTRUCTIONS PORTBEFORE COMPLETING FORM (T-/WU) RP 1 VT ACCESSION NO |PIENT’S CATALOG NUMBER AFAP...1.3 Program Approach 6 Ii SU0RY 10 2.1 Analytical 10 2.2 Materials Development 13 2.3 Bearing Development and Testing 16 III DISCUSSION 19 3.1 Engine...to 1200*F. -~ 18 SECTION III A DISCUSSION 3.1 Engine Characteristics The ETJ341-Pl engine was selected as the vehicle for the Sapplication of foil

  9. Goal-directed mechanisms that constrain retrieval predict subsequent memory for new "foil" information.

    PubMed

    Vogelsang, David A; Bonnici, Heidi M; Bergström, Zara M; Ranganath, Charan; Simons, Jon S

    2016-08-01

    To remember a previous event, it is often helpful to use goal-directed control processes to constrain what comes to mind during retrieval. Behavioral studies have demonstrated that incidental learning of new "foil" words in a recognition test is superior if the participant is trying to remember studied items that were semantically encoded compared to items that were non-semantically encoded. Here, we applied subsequent memory analysis to fMRI data to understand the neural mechanisms underlying the "foil effect". Participants encoded information during deep semantic and shallow non-semantic tasks and were tested in a subsequent blocked memory task to examine how orienting retrieval towards different types of information influences the incidental encoding of new words presented as foils during the memory test phase. To assess memory for foils, participants performed a further surprise old/new recognition test involving foil words that were encountered during the previous memory test blocks as well as completely new words. Subsequent memory effects, distinguishing successful versus unsuccessful incidental encoding of foils, were observed in regions that included the left inferior frontal gyrus and posterior parietal cortex. The left inferior frontal gyrus exhibited disproportionately larger subsequent memory effects for semantic than non-semantic foils, and significant overlap in activity during semantic, but not non-semantic, initial encoding and foil encoding. The results suggest that orienting retrieval towards different types of foils involves re-implementing the neurocognitive processes that were involved during initial encoding.

  10. Composite thin-foil bandpass filter for EUV astronomy Titanium-antimony-titanium

    NASA Technical Reports Server (NTRS)

    Jelinsky, P.; Martin, C.; Kimble, R.; Bowyer, S.; Steele, G.

    1983-01-01

    Thin metallic foils of antimony and titanium have been investigated in an attempt to develop an EUV filter with a bandpass from 350 to 550 A. A composite filter has been developed composed of antimony sandwiched between two titanium foils. The transmissions of sample composite foils and of pure titanium foils from 130 to 1216 A are presented. The absorption coefficients of anatimony and titanium and the effect of titanium oxide on the transmission are derived. The composite filter has been found to be quite stable and mechanically rugged. Among other uses, the filter shows substantial promise for EUV astronomy.

  11. Time-of-flight mass spectrometry of laser exploding foil initiated PETN samples

    NASA Astrophysics Data System (ADS)

    Fajardo, Mario E.; Molek, Christopher D.; Fossum, Emily C.

    2017-01-01

    We report the results of time-of-flight mass spectrometry (TOFMS) measurements of the gaseous products of thin-film pentaerythritol tetranitrate [PETN, C(CH2NO3)4] samples reacting in vacuo. The PETN sample spots are produced by masked physical vapor deposition [A.S. Tappan, et al., AIP Conf. Proc. 1426, 677 (2012)] onto a first-surface aluminum mirror. A pulsed laser beam imaged through the soda lime glass mirror substrate converts the aluminum layer into a high-temperature high-pressure plasma which initiates chemical reactions in the overlying PETN sample. We had previously proposed [E.C. Fossum, et al., AIP Conf. Proc. 1426, 235 (2012)] to exploit differences in gaseous product chemical identities and molecular velocities to provide a chemically-based diagnostic for distinguishing between "detonation-like" and deflagration responses. Briefly: we expect in-vacuum detonations to produce hyperthermal (v˜10 km/s) thermodynamically-stable products such as N2, CO2, and H2O, and for deflagrations to produce mostly reaction intermediates, such as NO and NO2, with much slower molecular velocities - consistent with the expansion-quenched thermal decomposition of PETN. We observe primarily slow reaction intermediates (NO2, CH2NO3) at low laser pulse energies, the appearance of NO at intermediate laser pulse energies, and the appearance of hyperthemal CO/N2 at mass 28 amu at the highest laser pulse energies. However, these results are somewhat ambiguous, as the NO, NO2, and CH2NO3 intermediates persist and all species become hyperthermal at the higher laser pulse energies. Also, the purported CO/N2 signal at 28 amu may be contaminated by silicon ablated from the glass mirror substrate. We plan to mitigate these problems in future experiments by adopting the "Buelow" sample configuration which employs an intermediate foil barrier to shield the energetic material from the laser and the laser driven plasma [S.J. Buelow, et al., AIP Conf. Proc. 706, 1377 (2003)].

  12. Effects of heat treatment on U–Mo fuel foils with a zirconium diffusion barrier

    SciTech Connect

    Jue, Jan-Fong; Trowbridge, Tammy L.; Breckenridge, Cynthia R.; Moore, Glenn A.; Meyer, Mitchell K.; Keiser, Dennis D.

    2015-05-01

    A monolith fuel design based on U–Mo alloy has been selected as the fuel type for conversion of the United States’ high performance research reactors (HPRRs) from highly enriched uranium (HEU) to low-enriched uranium (LEU). In this fuel design, a thin layer of zirconium is used to eliminate the direct interaction between the U–Mo fuel meat and the aluminum-alloy cladding during irradiation. The co-rolling process used to bond the Zr barrier layer to the U–Mo foil during fabrication alters the microstructure of both the U–10Mo fuel meat and the U–Mo/Zr interface. This work studied the effects of post-rolling annealing treatment on the microstructure of the co-rolled U–Mo fuel meat and the U–Mo/Zr interaction layer. Microscopic characterization shows that the grain size of U–Mo fuel meat increases with the annealing temperature, as expected. The grain sizes were ~9, ~13, and ~20 μm for annealing temperature of 650, 750, and 850 °C, respectively. No abnormal grain growth was observed. The U–Mo/Zr interaction-layer thickness increased with the annealing temperature with an Arrhenius constant for growth of 184 kJ/mole, consistent with a previous diffusion-couple study. The interaction layer thickness was 3.2 ± 0.5 μm, 11.1 ± 2.1 μm, 27.1 ± 0.9 μm for annealing temperature of 650, 750, to 850 °C, respectively. The homogeneity of Mo improves with post rolling annealing temperature and with U–Mo coupon homogenization. The phases in the Zr/U–Mo interaction layer produced by co-rolling, however, differ from those reported in the previous diffusion couple studies.

  13. Aluminum Carbothermic Technology

    SciTech Connect

    Bruno, Marshall J.

    2005-03-31

    This report documents the non-proprietary research and development conducted on the Aluminum Carbothermic Technology (ACT) project from contract inception on July 01, 2000 to termination on December 31, 2004. The objectives of the program were to demonstrate the technical and economic feasibility of a new carbothermic process for producing commercial grade aluminum, designated as the ''Advanced Reactor Process'' (ARP). The scope of the program ranged from fundamental research through small scale laboratory experiments (65 kW power input) to larger scale test modules at up to 1600 kW power input. The tasks included work on four components of the process, Stages 1 and 2 of the reactor, vapor recovery and metal alloy decarbonization; development of computer models; and economic analyses of capital and operating costs. Justification for developing a new, carbothermic route to aluminum production is defined by the potential benefits in reduced energy, lower costs and more favorable environmental characteristics than the conventional Hall-Heroult process presently used by the industry. The estimated metrics for these advantages include energy rates at approximately 10 kWh/kg Al (versus over 13 kWh/kg Al for Hall-Heroult), capital costs as low as $1250 per MTY (versus 4,000 per MTY for Hall-Heroult), operating cost reductions of over 10%, and up to 37% reduction in CO2 emissions for fossil-fuel power plants. Realization of these benefits would be critical to sustaining the US aluminum industries position as a global leader in primary aluminum production. One very attractive incentive for ARP is its perceived ability to cost effectively produce metal over a range of smelter sizes, not feasible for Hall-Heroult plants which must be large, 240,000 TPY or more, to be economical. Lower capacity stand alone carbothermic smelters could be utilized to supply molten metal at fabrication facilities similar to the mini-mill concept employed by the steel industry. Major

  14. 21 CFR 73.1645 - Aluminum powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  15. 21 CFR 73.1645 - Aluminum powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  16. 21 CFR 73.1645 - Aluminum powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  17. 21 CFR 73.1645 - Aluminum powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  18. 21 CFR 73.1645 - Aluminum powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  19. A simple method for the measurement of reflective foil emissivity

    NASA Astrophysics Data System (ADS)

    Ballico, M. J.; van der Ham, E. W. M.

    2013-09-01

    Reflective metal foil is widely used to reduce radiative heat transfer within the roof space of buildings. Such foils are typically mass-produced by vapor-deposition of a thin metallic coating onto a variety of substrates, ranging from plastic-coated reinforced paper to "bubble-wrap". Although the emissivity of such surfaces is almost negligible in the thermal infrared, typically less than 0.03, an insufficiently thick metal coating, or organic contamination of the surface, can significantly increase this value. To ensure that the quality of the installed insulation is satisfactory, Australian building code AS/NZS 4201.5:1994 requires a practical agreed method for measurement of the emissivity, and the standard ASTM-E408 is implied. Unfortunately this standard is not a "primary method" and requires the use of specified expensive apparatus and calibrated reference materials. At NMIA we have developed a simple primary technique, based on an apparatus to thermally modulate the sample and record the apparent modulation in infra-red radiance with commercially available radiation thermometers. The method achieves an absolute accuracy in the emissivity of approximately 0.004 (k=2). This paper theoretically analyses the equivalence between the thermal emissivity measured in this manner, the effective thermal emissivity in application, and the apparent emissivity measured in accordance with ASTM-E408.

  20. A simple method for the measurement of reflective foil emissivity

    SciTech Connect

    Ballico, M. J.; Ham, E. W. M. van der

    2013-09-11

    Reflective metal foil is widely used to reduce radiative heat transfer within the roof space of buildings. Such foils are typically mass-produced by vapor-deposition of a thin metallic coating onto a variety of substrates, ranging from plastic-coated reinforced paper to 'bubble-wrap'. Although the emissivity of such surfaces is almost negligible in the thermal infrared, typically less than 0.03, an insufficiently thick metal coating, or organic contamination of the surface, can significantly increase this value. To ensure that the quality of the installed insulation is satisfactory, Australian building code AS/NZS 4201.5:1994 requires a practical agreed method for measurement of the emissivity, and the standard ASTM-E408 is implied. Unfortunately this standard is not a 'primary method' and requires the use of specified expensive apparatus and calibrated reference materials. At NMIA we have developed a simple primary technique, based on an apparatus to thermally modulate the sample and record the apparent modulation in infra-red radiance with commercially available radiation thermometers. The method achieves an absolute accuracy in the emissivity of approximately 0.004 (k=2). This paper theoretically analyses the equivalence between the thermal emissivity measured in this manner, the effective thermal emissivity in application, and the apparent emissivity measured in accordance with ASTM-E408.

  1. Fission fragment assisted reactor concept for space propulsion: Foil reactor

    NASA Technical Reports Server (NTRS)

    Wright, Steven A.

    1991-01-01

    The concept is to fabricate a reactor using thin films or foils of uranium, uranium oxide and then to coat them on substrates. These coatings would be made so thin as to allow the escaping fission fragments to directly heat a hydrogen propellant. The idea was studied of direct gas heating and direct gas pumping in a nuclear pumped laser program. Fission fragments were used to pump lasers. In this concept two substrates are placed opposite each other. The internal faces are coated with thin foil of uranium oxide. A few of the advantages of this technology are listed. In general, however, it is felt that if one look at all solid core nuclear thermal rockets or nuclear thermal propulsion methods, one is going to find that they all pretty much look the same. It is felt that this reactor has higher potential reliability. It has low structural operating temperatures, very short burn times, with graceful failure modes, and it has reduced potential for energetic accidents. Going to a design like this would take the NTP community part way to some of the very advanced engine designs, such as the gas core reactor, but with reduced risk because of the much lower temperatures.

  2. Effect of defence response time during lunge in foil fencing.

    PubMed

    Gutiérrez-Cruz, Carmen; Rojas, F Javier; Gutiérrez-Davila, Marcos

    2016-01-01

    The aim of this study was to analyse the effect of stimulus change timing on reaction response time parameters, horizontal velocity of the centre of mass (CM) and precision during offensive actions in fencing. Twelve fencers from the Spanish National Foil Team were included in the study. Two 500 Hz force plates were used to register the horizontal component of the reaction force while a 3D video camera set at 250 Hz recorded the spatial position of 11 body markers and a projector connected to a programmed stopwatch projected a moving target (stimulus) on a screen. When the circle (target) appeared in the centre of the plastron, fencers had to execute a step-forward-lunge as fast as possible, trying to touch the circle with the tip of the foil. During the lunge, the position of the target could randomly shift or not to three different positions. The stimulus change was performed randomly at four different times with a progressive delay. The results show that target changes did not have any effect when they occurred at the beginning of the movement sequence. However, when the target change was delayed, reaction and movement times increased and the technical execution of the lunge changed, leading to more errors.

  3. Influence of copper foil polycrystalline structure on graphene anisotropic etching

    NASA Astrophysics Data System (ADS)

    Sharma, Kamal P.; Mahyavanshi, Rakesh D.; Kalita, Golap; Tanemura, Masaki

    2017-01-01

    Anisotropic etching of graphene and other two dimensional materials is an important tool to understand the growth process as well as enabling fabrication of various well-defined structures. Here, we reveal the influence of copper foil polycrystalline structure on anisotropic etching process of as-synthesized graphene. Graphene crystals were synthesized on the polycrystalline Cu foil by a low-pressure chemical vapor deposition (LPCVD) system. Microscopic analysis shows difference in shape, size and stripes alignment of graphene crystals with dissimilar nucleation within closure vicinity of neighboring Cu grains. Post-growth etching of such graphene crystals also significantly affected by the crystallographic nature of Cu grains as observed by the field emission scanning electron microscope (FE-SEM) and electron back scattered diffraction (EBSD) analysis. Hexagonal hole formation with anisotropic etching is observed to be independent of the stripes and wrinkles in the synthesized graphene. We also observed variation in etched pattern of the graphene depending on the base Cu grain orientations, attributing to difference in nucleation and growth process. The findings can facilitate to understand the nature of microscopic etched pattern depending on metal catalyst crystallographic structure.

  4. The radiation reaction effect in ultra intense laser foil interactions

    NASA Astrophysics Data System (ADS)

    Klimo, O.; Jirka, M.; Masek, M.; Limpouch, J.; Bussmann, M.; Korn, G.

    2013-05-01

    Since the radiation reaction effect on electron propagation is very small in most cases, it can be usually neglected and the Lorentz force equation can be applied. However, ultra-intense lasers with normalized vector potential of the order of 100 can accelerate electrons to relativistic velocities with very high gamma factor. When the electron is accelerated to such high velocities the amount of emitted radiation may become large and radiation damping and emission of energetic photons should be considered. This work studies the influence of the radiation reaction force on laser interaction with solid foil targets. It compares different approaches adopted in PIC simulations to take into account the radiation reaction. The simulations of a counter-propagating relativistic electron and an ultra-intense laser beam demonstrate a strong energy loss of electrons due to non-linear Compton scattering. The interaction of ultra-intense laser pulse with solid foil is studied using PIC simulations. It is shown that the effect of radiation reaction strongly depends on the recirculation of high-energy electrons. When the recirculation is efficient, the radiation coming from the target is much more intense and it shows different spectral and angular characteristics.

  5. Mineral of the month: aluminum

    USGS Publications Warehouse

    Plunkert, Patricia A.

    2005-01-01

    Aluminum is the second most abundant metallic element in Earth’s crust after silicon. Even so, it is a comparatively new industrial metal that has been produced in commercial quantities for little more than 100 years. Aluminum is lightweight, ductile, malleable and corrosion resistant, and is a good conductor of heat and electricity. Weighing about one-third as much as steel or copper per unit of volume, aluminum is used more than any other metal except iron. Aluminum can be fabricated into desired forms and shapes by every major metalworking technique to add to its versatility.

  6. Laser welding of aluminum alloys

    SciTech Connect

    Leong, K.H.; Sabo, K.R.; Sanders, P.G.; Spawr, W.J.

    1997-03-01

    Recent interest in reducing the weight of automobiles to increase fuel mileage has focused attention on the use of aluminum and associated joining technologies. Laser beam welding is one of the more promising methods for high speed welding of aluminum. Consequently, substantial effort has been expended in attempting to develop a robust laser beam welding process. Early results have not been very consistent in the process requirements but more definitive data has been produced recently. This paper reviews the process parameters needed to obtain consistent laser welds on 5,000 series aluminum alloys and discusses the research necessary to make laser processing of aluminum a reality for automotive applications.

  7. Production of aluminum metal by electrolysis of aluminum sulfide

    DOEpatents

    Minh, N.Q.; Loutfy, R.O.; Yao, N.P.

    1982-04-01

    Metallic aluminum may be produced by the electrolysis of Al/sub 2/S/sub 3/ at 700 to 800/sup 0/C in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

  8. Production of aluminum metal by electrolysis of aluminum sulfide

    DOEpatents

    Minh, Nguyen Q.; Loutfy, Raouf O.; Yao, Neng-Ping

    1984-01-01

    Production of metallic aluminum by the electrolysis of Al.sub.2 S.sub.3 at 700.degree.-800.degree. C. in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

  9. Prism Foil from an LCD Monitor as a Tool for Teaching Introductory Optics

    ERIC Educational Resources Information Center

    Planinsic, Gorazd; Gojkosek, Mihael

    2011-01-01

    Transparent prism foil is part of a backlight system in LCD monitors that are widely used today. This paper describes the optical properties of the prism foil and several pedagogical applications suitable for undergraduate introductory physics level. Examples include experiments that employ refraction, total internal reflection, diffraction and…

  10. Effects of the foil flatness on irradiation performance of U10Mo monolithic mini-plates

    DOE PAGES

    Ozaltun, Hakan; Medvedev, Pavel G.; Rabin, Barry H.

    2015-09-03

    Monolithic plate-type fuels comprise of a high density, low enrichment, U10Mo fuel foil encapsulated in a cladding material. This concept generates several fabrication challenges such as flatness, centering or thickness variation. There are concerns, if these parameters have implications on overall performance. To investigate these inquiries, the effects of the foil flatness were studied. For this, a representative plate was simulated for an ideal case. The simulations were repeated for additional cases with various foil curvatures to evaluate the effects on the irradiation performance. The results revealed that the stresses and strains induced by fabrication process are not affected bymore » the flatness of the foil. Furthermore, fabrication stresses in the foil are relieved relatively fast in the reactor. The effects of the foil flatness on peak irradiation stressstrains are minimal. There is a slight increase in temperature for the case with maximum curvature. The major impact is on the displacement characteristics. Furthermore, while the case with a flat foil produces a symmetrical swelling, if the foil is curved, more swelling occurs on the thin-cladding side and the plate bows during irradiation.« less

  11. Effects of the foil flatness on irradiation performance of U10Mo monolithic mini-plates

    SciTech Connect

    Ozaltun, Hakan; Medvedev, Pavel G.; Rabin, Barry H.

    2015-09-03

    Monolithic plate-type fuels comprise of a high density, low enrichment, U10Mo fuel foil encapsulated in a cladding material. This concept generates several fabrication challenges such as flatness, centering or thickness variation. There are concerns, if these parameters have implications on overall performance. To investigate these inquiries, the effects of the foil flatness were studied. For this, a representative plate was simulated for an ideal case. The simulations were repeated for additional cases with various foil curvatures to evaluate the effects on the irradiation performance. The results revealed that the stresses and strains induced by fabrication process are not affected by the flatness of the foil. Furthermore, fabrication stresses in the foil are relieved relatively fast in the reactor. The effects of the foil flatness on peak irradiation stressstrains are minimal. There is a slight increase in temperature for the case with maximum curvature. The major impact is on the displacement characteristics. Furthermore, while the case with a flat foil produces a symmetrical swelling, if the foil is curved, more swelling occurs on the thin-cladding side and the plate bows during irradiation.

  12. 21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Tin-coated lead foil capsules for wine bottles... Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine... and neck areas) on wine bottles to prevent insect infestation, as a barrier to oxygen, and...

  13. Aluminum nitride grating couplers.

    PubMed

    Ghosh, Siddhartha; Doerr, Christopher R; Piazza, Gianluca

    2012-06-10

    Grating couplers in sputtered aluminum nitride, a piezoelectric material with low loss in the C band, are demonstrated. Gratings and a waveguide micromachined on a silicon wafer with 600 nm minimum feature size were defined in a single lithography step without partial etching. Silicon dioxide (SiO(2)) was used for cladding layers. Peak coupling efficiency of -6.6 dB and a 1 dB bandwidth of 60 nm have been measured. This demonstration of wire waveguides and wideband grating couplers in a material that also has piezoelectric and elasto-optic properties will enable new functions for integrated photonics and optomechanics.

  14. Characterization of ultradispersed aluminum

    SciTech Connect

    Simpson, R.L.; Maienschein, J.L.; Swansiger, R.W.; Garcia, F.; Darling, D.H.

    1994-12-08

    Samples of ultradispersed Al were received, which were produced by electrically exploding Al wires in argon. These samples comprised very small particles that were not significantly oxidized and that were stable in air. Particle morphology were studied with SE, micropycnometry, and gas adsorption surface area. Composition were determined using various techniques, as were thermal stability and reaction exotherms. The inexplicable reports of an Al-Ar compound and of an exothermic reaction were not confirmed. The material is a stable, nonoxidized, small-particle, highly reactive form of aluminum that is of interest in energetic materials formulations.

  15. Foil assisted replica molding for fabrication of microfluidic devices and their application in vitro.

    PubMed

    Micheal, Issac J; Vidyasagar, Aditya J; Bokara, Kiran Kumar; Mekala, Naveen Kumar; Asthana, Amit; Rao, Ch Mohan

    2014-10-07

    We present a simple, rapid, benchtop, Foil Assisted Rapid Molding (FARM) method for the fabrication of microfluidic devices. This novel technique involves the use of aluminium foil, pen and an X-Y plotter to create semi-circular or plano-concave, shallow microchannels. It is an easy do-it-yourself (DIY) technique for creating a microfluidic device in three simple steps: (1) create a channel design using the CAD software, (2) plot the patterns on aluminium foil and (3) use the reverse of the engraved foil as a mold to create microfluidic devices. In this report, we present a detailed study of the proposed method by varying a range of parameters such as foil thickness, tip material, and tip sizes and by investigating their effect on the creation of channels with varying geometry. Furthermore, we demonstrated the cytocompatibility of these devices in vitro.

  16. Lead foil in dental X-ray film: Backscattering rejection or image intensifier?

    NASA Astrophysics Data System (ADS)

    Hönnicke, M. G.; Delben, G. J.; Godoi, W. C.; Swinka-Filho, V.

    2014-11-01

    Dental X-ray films are still largely used due to sterilization issues, simplicity and, mainly, economic reasons. These films almost always are double coated (double emulsion) and have a lead foil in contact with the film for X-ray backscattering rejection. Herein we explore the use of the lead foil as an image intensifier. In these studies, spatial resolution was investigated when images were acquired on the dental X-ray films with and without the lead foil. Also, the lead foil was subjected to atomic analysis (fluorescent measurements) and structure analysis (X-ray diffraction). We determined that the use of the lead foil reduces the exposure time, however, does not affect the spatial resolution on the acquired images. This suggests that the fluorescent radiation spread is smaller than the grain sizes of the dental X-ray films.

  17. Design, fabrication, and performance of foil journal bearing for the brayton rotating unit

    NASA Technical Reports Server (NTRS)

    Licht, L.; Branger, M.

    1973-01-01

    Foil bearings were designed and manufactured to replace pivoted-shoe journal bearings in an existing Brayton Cycle turbo-alternator-compressor. The design of this unconventional rotor support was accomplished within the constraints and space limitations imposed by the present machine, and the substitution of foil bearings was effected without changes or modification other machine components. A housing and a test rig were constructed to incorporate the new foil-bearing support into a unified assemble with an air-driven rotor and the gimbal-mounted thrust bearing, seals, and shrouds of an actual Brayton Rotating Unit. The foil bearing required no external pressure source, and stable self-acting rotation was achieved at all speeds up to 43,200 rpm. Excellent wipe-wear characteristics of the foil bearing permitted well over 1000 start-stop cycles with no deterioriation of performance in the entire speed range.

  18. High-power laser shock-induced dynamic fragmentation of iron foils

    NASA Astrophysics Data System (ADS)

    Morard, G.; de Rességuier, T.; Vinci, T.; Benuzzi-Mounaix, A.; Lescoute, E.; Brambrink, E.; Koenig, M.; Wei, H.; Diziere, A.; Occelli, F.; Fiquet, G.; Guyot, F.

    2010-11-01

    High-power laser shots were performed on 100-μm -thick iron foils, leading to shock loading pressures ranging from about 100 to 300 GPa. Free surface velocities were measured by interferometry. Ejected fragments recovered on polycarbonate shields were analyzed using scanning electron microscopy. Particle-size distributions were extracted from backscattered electrons images. These distributions, as well as the morphologies of fragments and the values of the tensile strength, change abruptly with increasing laser intensity. One-dimensional hydrodynamic simulations were performed in order to interpret these evolutions. By comparison with recent static measurements and calculations of the iron phase diagram, the BLF (Bushman, Lomonosov and Fortov) equation of state was inferred to provide more realistic predictions than SESAME 2150 at the highest pressures investigated. The calculated decompression paths show that spall fracturation took place in the solid state, either in α or in γ iron, this phase difference being the simplest hypothesis for explaining the changes observed in the fragmentation behavior.

  19. Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

    SciTech Connect

    Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

    2007-08-16

    Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

  20. Characterization of the Fine Component of Comet Wild 2: Analysis of 11 Stardust Craters from Foil C2010W

    NASA Astrophysics Data System (ADS)

    Haas, B. A.; Croat, T. K.; Floss, C.

    2016-08-01

    NASA's Stardust mission returned cometary material from comet Wild 2 in Al foil collectors. We report on SEM-EDX and Auger elemental analysis as well as FIB-TEM analysis performed on 11 craters from foil C2010W.

  1. Vortex-wake interactions of a flapping foil that models animal swimming and flight.

    PubMed

    Lentink, David; Muijres, Florian T; Donker-Duyvis, Frits J; van Leeuwen, Johan L

    2008-01-01

    The fluid dynamics of many swimming and flying animals involves the generation and shedding of vortices into the wake. Here we studied the dynamics of similar vortices shed by a simple two-dimensional flapping foil in a soap-film tunnel. The flapping foil models an animal wing, fin or tail in forward locomotion. The vortical flow induced by the foil is correlated to (the resulting) thickness variations in the soap film. We visualized these thickness variations through light diffraction and recorded it with a digital high speed camera. This set-up enabled us to study the influence of foil kinematics on vortex-wake interactions. We varied the dimensionless wavelength of the foil (lambda*=4-24) at a constant dimensionless flapping amplitude (A*=1.5) and geometric angle of attack amplitude (A(alpha,geo)=15 degrees ). The corresponding Reynolds number was of the order of 1000. Such values are relevant for animal swimming and flight. We found that a significant leading edge vortex (LEV) was generated by the foil at low dimensionless wavelengths (lambda*<10). The LEV separated from the foil for all dimensionless wavelengths. The relative time (compared with the flapping period) that the unstable LEV stayed above the flapping foil increased for decreasing dimensionless wavelengths. As the dimensionless wavelength decreased, the wake dynamics evolved from a wavy von Kármán-like vortex wake shed along the sinusoidal path of the foil into a wake densely packed with large interacting vortices. We found that strongly interacting vortices could change the wake topology abruptly. This occurred when vortices were close enough to merge or tear each other apart. Our experiments show that relatively small changes in the kinematics of a flapping foil can alter the topology of the vortex wake drastically.

  2. The Benefits of Aluminum Windows.

    ERIC Educational Resources Information Center

    Goyal, R. C.

    2002-01-01

    Discusses benefits of aluminum windows for college construction and renovation projects, including that aluminum is the most successfully recycled material, that it meets architectural glass deflection standards, that it has positive thermal energy performance, and that it is a preferred exterior surface. (EV)

  3. Lost-Soap Aluminum Casting.

    ERIC Educational Resources Information Center

    Mihalow, Paula

    1980-01-01

    Lost-wax casting in sterling silver is a costly experience for the average high school student. However, this jewelry process can be learned at no cost if scrap aluminum is used instead of silver, and soap bars are used instead of wax. This lost-soap aluminum casting process is described. (Author/KC)

  4. Aluminum Nanoholes for Optical Biosensing

    PubMed Central

    Barrios, Carlos Angulo; Canalejas-Tejero, Víctor; Herranz, Sonia; Urraca, Javier; Moreno-Bondi, María Cruz; Avella-Oliver, Miquel; Maquieira, Ángel; Puchades, Rosa

    2015-01-01

    Sub-wavelength diameter holes in thin metal layers can exhibit remarkable optical features that make them highly suitable for (bio)sensing applications. Either as efficient light scattering centers for surface plasmon excitation or metal-clad optical waveguides, they are able to form strongly localized optical fields that can effectively interact with biomolecules and/or nanoparticles on the nanoscale. As the metal of choice, aluminum exhibits good optical and electrical properties, is easy to manufacture and process and, unlike gold and silver, its low cost makes it very promising for commercial applications. However, aluminum has been scarcely used for biosensing purposes due to corrosion and pitting issues. In this short review, we show our recent achievements on aluminum nanohole platforms for (bio)sensing. These include a method to circumvent aluminum degradation—which has been successfully applied to the demonstration of aluminum nanohole array (NHA) immunosensors based on both, glass and polycarbonate compact discs supports—the use of aluminum nanoholes operating as optical waveguides for synthesizing submicron-sized molecularly imprinted polymers by local photopolymerization, and a technique for fabricating transferable aluminum NHAs onto flexible pressure-sensitive adhesive tapes, which could facilitate the development of a wearable technology based on aluminum NHAs. PMID:26184330

  5. Primary Aluminum Plants Worldwide - 1998

    USGS Publications Warehouse

    1999-01-01

    The 1990 U.S. Bureau of Mines publication, Primary Aluminum Plants Worldwide, has been updated and is now available. The 1998 USGS edition of Primary Aluminum Plants Worldwide is published in two parts. Part I—Detail contains information on individual primary smelter capacity, location, ownership, sources of energy, and other miscellaneous information. Part II—Summary summarizes the capacity data by country

  6. Performance and lifetime of solar mirror foils in space

    SciTech Connect

    Fink, D.; Biersack, J.P.; Staedele, M.

    1985-01-01

    The results of a Monte Carlo computer analysis of the long term effects of space radiation on the surfaces of giant orbiting mirrors are presented. The mirrors, thin surfaced and made of substances like, e.g., Mylar and Hostephan, which are polymers, would reflect solar radiation to earth and be of a size equivalent to that of the area they would illumine. Possible applications are the warming of cities, melting of icebergs in shipping lanes and the illumination of solar power plants. Attention was focused on the changes produced in the reflective surface by solar wind particle bombardment. It was found that an Al covering at least 0.1 mm thick would be needed for protection. Nevertheless, the surface would be destroyed by blistering and foil carbonization within 10 yr and would then require replacement. 12 references.

  7. Oxidation-assisted graphene heteroepitaxy on copper foil.

    PubMed

    Reckinger, Nicolas; Tang, Xiaohui; Joucken, Frédéric; Lajaunie, Luc; Arenal, Raul; Dubois, Emmanuel; Hackens, Benoît; Henrard, Luc; Colomer, Jean-François

    2016-11-10

    We propose an innovative, easy-to-implement approach to synthesize aligned large-area single-crystalline graphene flakes by chemical vapor deposition on copper foil. This method doubly takes advantage of residual oxygen present in the gas phase. First, by slightly oxidizing the copper surface, we induce grain boundary pinning in copper and, in consequence, the freezing of the thermal recrystallization process. Subsequent reduction of copper under hydrogen suddenly unlocks the delayed reconstruction, favoring the growth of centimeter-sized copper (111) grains through the mechanism of abnormal grain growth. Second, the oxidation of the copper surface also drastically reduces the nucleation density of graphene. This oxidation/reduction sequence leads to the synthesis of aligned millimeter-sized monolayer graphene domains in epitaxial registry with copper (111). The as-grown graphene flakes are demonstrated to be both single-crystalline and of high quality.

  8. Folding/Unfolding Properties of Metal Foils in Transformable Structure

    NASA Astrophysics Data System (ADS)

    Daming, Nie; Zhen, Lu; Kaifeng, Zhang

    2016-11-01

    Transformable structures are widely applied in the aerospace, temporary facilities, etc. Compared to the structures made of polyester materials, the metal foil ones occupy many special advantages while have been rarely investigated. In this study, a series of transformable structures made of four different metal materials, 6065 Al, copper, TA1 and SUS 304 stainless steel, with thickness of 0.1 mm were prepared. Moreover, the folding (i.e., compressing the structure to the lowest height with external force) and unfolding (i.e., extending the structure to the largest height with external force) behaviors of these structures were exhibited and explained by experiments. Besides, the differences and corresponding mechanisms of various materials on the folding/unfolding properties of the structures were examined and discussed.

  9. Recalibration of indium foil for personnel screening in criticality accidents.

    PubMed

    Takada, C; Tsujimura, N; Mikami, S

    2011-03-01

    At the Nuclear Fuel Cycle Engineering Laboratories of the Japan Atomic Energy Agency (JAEA), small pieces of indium foil incorporated into personal dosemeters have been used for personnel screening in criticality accidents. Irradiation tests of the badges were performed using the SILENE reactor to verify the calibration of the indium activation that had been made in the 1980s and to recalibrate them for simulated criticalities that would be the most likely to occur in the solution process line. In addition, Monte Carlo calculations of the indium activation using the badge model were also made to complement the spectral dependence. The results lead to a screening level of 15 kcpm being determined that corresponds to a total dose of 0.25 Gy, which is also applicable in posterior-anterior exposure. The recalibration based on the latest study will provide a sounder basis for the screening procedure in the event of a criticality accident.

  10. Folding/Unfolding Properties of Metal Foils in Transformable Structure

    NASA Astrophysics Data System (ADS)

    Daming, Nie; Zhen, Lu; Kaifeng, Zhang

    2017-01-01

    Transformable structures are widely applied in the aerospace, temporary facilities, etc. Compared to the structures made of polyester materials, the metal foil ones occupy many special advantages while have been rarely investigated. In this study, a series of transformable structures made of four different metal materials, 6065 Al, copper, TA1 and SUS 304 stainless steel, with thickness of 0.1 mm were prepared. Moreover, the folding (i.e., compressing the structure to the lowest height with external force) and unfolding (i.e., extending the structure to the largest height with external force) behaviors of these structures were exhibited and explained by experiments. Besides, the differences and corresponding mechanisms of various materials on the folding/unfolding properties of the structures were examined and discussed.

  11. Visualization of terahertz surface waves propagation on metal foils

    PubMed Central

    Wang, Xinke; Wang, Sen; Sun, Wenfeng; Feng, Shengfei; Han, Peng; Yan, Haitao; Ye, Jiasheng; Zhang, Yan

    2016-01-01

    Exploitation of surface plasmonic devices (SPDs) in the terahertz (THz) band is always beneficial for broadening the application potential of THz technologies. To clarify features of SPDs, a practical characterization means is essential for accurately observing the complex field distribution of a THz surface wave (TSW). Here, a THz digital holographic imaging system is employed to coherently exhibit temporal variations and spectral properties of TSWs activated by a rectangular or semicircular slit structure on metal foils. Advantages of the imaging system are comprehensively elucidated, including the exclusive measurement of TSWs and fall-off of the time consumption. Numerical simulations of experimental procedures further verify the imaging measurement accuracy. It can be anticipated that this imaging system will provide a versatile tool for analyzing the performance and principle of SPDs. PMID:26729652

  12. Flow structures in the wake of heaving and pitching foils

    NASA Astrophysics Data System (ADS)

    Najdzin, Derek; Pardo, Enrique; Leftwich, Megan C.; Bardet, Philippe M.

    2012-11-01

    A 10-bar mechanism drives a cambering hydrofoil in an oscillatory heaving and pitching motion that replicates the flapping motion of a dolphin tail. The mechanism sits on a force-balance with six strain gages that together measure the forces and moments experienced by the fin during an oscillation. Planar Laser-Induced Fluorescence is used to image the flow structures created downstream of the cambering fin for a range of Reynolds and Strouhal numbers. The images are taken in the mid-plane, parallel to the bottom of the water tunnel. These results are compared to a rigid foil at matching conditions to investigate the role of camber changes during the flapping cycle.

  13. An Innovative Method for Manufacturing Gamma-TiAl Foil

    NASA Technical Reports Server (NTRS)

    Hales, Stephen J.; Saqib, Mohammad; Alexa, Joel A.

    2003-01-01

    The manufacture and entrance into service of thin gage gamma-TiAl product has been hampered by the inherent low room temperature ductility of the material. In the present study a new approach was explored for the efficient manufacture of gamma-TiAl foil with improved ductility. The objective was to produce a very clean material (low interstitial content) with a highly refined, homogeneous microstructure placed in a fully lamellar condition. The processing route involved the use of RF plasma spray deposition of pre-alloyed powders, followed by consolidation via vacuum hot pressing and heat treatment. The approach took advantage of a deposition process which included no electrodes, no binders and high cooling rates. Results and discussion of the work performed to date are presented.

  14. Multilayer roll bonded aluminium foil: processing, microstructure and flow stress

    SciTech Connect

    Barlow, C.Y.; Nielsen, P.; Hansen, N

    2004-08-02

    Bulk aluminium has been produced by warm-rolling followed by cold-rolling of commercial purity (99% purity) aluminium foil. The bonding appeared perfect from observation with the naked eye, light and transmission electron microscopy. By comparison with bulk aluminium of similar purity (AA1200) rolled to a similar strain (90%RA), the roll-bonded metal showed a much higher density of high-angle grain boundaries, similar strength and improved thermal stability. This study has implications for a number of applications in relation to the processing of aluminium. Roll bonding is of interest as a method for grain size refinement; oxide-containing materials have increased strength, enhanced work-hardening behaviour, and exhibit alterations in recrystallisation behaviour. The behaviour of the hard oxide film is of interest in aluminium processing, and has been investigated by characterising the size and distribution of oxide particles in the roll-bonded samples.

  15. Transitions in the wake of a flapping foil.

    PubMed

    Godoy-Diana, Ramiro; Aider, Jean-Luc; Wesfreid, José Eduardo

    2008-01-01

    We study experimentally the vortex streets produced by a flapping foil in a hydrodynamic tunnel, using two-dimensional particle image velocimetry. An analysis in terms of a flapping frequency-amplitude phase space allows the identification of (i) the transition from the well-known Bénard-von Kármán (BvK) wake to the reverse BvK vortex street that characterizes propulsive wakes, and (ii) the symmetry breaking of this reverse BvK pattern giving rise to an asymmetric wake. We also show that the transition from a BvK wake to a reverse BvK wake precedes the actual drag-thrust transition and we discuss the significance of the present results in the analysis of flapping systems in nature.

  16. Pulse shortening via Relativistic Transparency of Nanometer Foils

    NASA Astrophysics Data System (ADS)

    Shah, R. C.; Palaniyappan, S.; Wu, H.-C.; Gautier, D. C.; Jung, D.; Hoerlein, R.; Offermann, D.; Johnson, R. P.; Shimada, T.; Letzring, S.; Yin, L.; Albright, B.; Fernandez, J. C.; Hegelich, B. M.

    2010-11-01

    Intense lasers drive plasma electrons to velocities approaching light-speed. Increase of the electron mass causes optical transparency in otherwise classically over-dense plasma. Simulations indicate relativistic transparency can produce near-single-cycle rise time light pulses. It also lies enables a new mechanism for laser-based ion-acceleration yielding energy increases over earlier approaches. A direct signature of transparency is pulse-shortening thru over-dense plasmas in which relativistic intensity induces transmission. Using nm C foils (LMU) and the high-contrast Trident laser (LANL) we have made auto-correlation measurements showing >2x transmitted pulse duration reduction at intensities corresponding to ˜20-fold increase in electron mass. Spectral measurements agree with pulse shortening thru the target, and 1-D particle-in-cell simulations support the measurements.

  17. Wettability of Aluminum on Alumina

    NASA Astrophysics Data System (ADS)

    Bao, Sarina; Tang, Kai; Kvithyld, Anne; Tangstad, Merete; Engh, Thorvald Abel

    2011-12-01

    The wettability of molten aluminum on solid alumina substrate has been investigated by the sessile drop technique in a 10-8 bar vacuum or under argon atmosphere in the temperature range from 1273 K to 1673 K (1000 °C to 1400 °C). It is shown that the reduction of oxide skin on molten aluminum is slow under normal pressures even with ultralow oxygen potential, but it is enhanced in high vacuum. To describe the wetting behavior of the Al-Al2O3 system at lower temperatures, a semiempirical calculation was employed. The calculated contact angle at 973 K (700 °C) is approximately 97 deg, which indicates that aluminum does not wet alumina at aluminum casting temperatures. Thus, a priming height is required for aluminum to infiltrate a filter. Wetting in the Al-Al2O3 system increases with temperature.

  18. Transmission Electron Microscopy of Cometary Residues from Micron-Sized Craters in the Stardust Al-Foils

    NASA Technical Reports Server (NTRS)

    Leroux, Hugues; Stroud, Rhonda M.; Dai, Zu Rong; Graham, Giles A.; Troadec, David; Bradley, John P.; Teslich, Nick; Borg, Janet; Kearsley, Anton T.; Horz, Friedrich

    2008-01-01

    We report Transmission Electron Microscopy (TEM) investigations of micro-craters that originated from hypervelocity impacts of comet 81P/Wild 2 dust particles on the aluminium foil of the Stardust collector. The craters were selected by Scanning Electron Microscopy (SEM) and then prepared by Focused Ion Beam (FIB) milling techniques in order to provide electron transparent cross-sections for TEM studies. The crater residues contain both amorphous and crystalline materials in varying proportions and compositions. The amorphous component is interpreted as resulting from shock melting during the impact and the crystalline phases as relict minerals. The latter show evidence for shock metamorphism. Based on the residue morphology and the compositional variation, the impacting particles are inferred to have been dominated by mixtures of submicron olivine, pyroxene and Fe-sulfide grains, in agreement with prior results of relatively coarse-grained mineral assemblages in the aerogel collector.

  19. X-Ray Absorption Spectroscopy Of Thin Foils Irradiated By An Ultra-short Laser Pulse

    SciTech Connect

    Renaudin, P.; Blancard, C.; Cosse, P.; Faussurier, G.; Lecherbourg, L.; Audebert, P.; Bastiani-Ceccotti, S.; Geindre, J.-P.; Shepherd, R.

    2007-08-02

    Point-projection K-shell absorption spectroscopy has been used to measure absorption spectra of transient plasma created by an ultra-short laser pulse. The 1s-2p and 1s-3p absorption lines of weakly ionized aluminum and the 2p-3d absorption lines of bromine were measured over an extended range of densities in a low-temperature regime. Independent plasma characterization was obtained using frequency domain interferometry diagnostic (FDI) that allows the interpretation of the absorption spectra in terms of spectral opacities. Assuming local thermodynamic equilibrium, spectral opacity calculations have been performed using the density and temperature inferred from the FDI diagnostic to compare to the measured absorption spectra. A good agreement is obtained when non-equilibrium effects due to non-stationary atomic physics are negligible at the x-ray probe time.

  20. X-Ray Absorption Spectroscopy Of Thin Foils Irradiated By An Ultra-short Laser Pulse

    NASA Astrophysics Data System (ADS)

    Renaudin, P.; Lecherbourg, L.; Blancard, C.; Cossé, P.; Faussurier, G.; Audebert, P.; Bastiani-Ceccotti, S.; Geindre, J.-P.; Shepherd, R.

    2007-08-01

    Point-projection K-shell absorption spectroscopy has been used to measure absorption spectra of transient plasma created by an ultra-short laser pulse. The 1s-2p and 1s-3p absorption lines of weakly ionized aluminum and the 2p-3d absorption lines of bromine were measured over an extended range of densities in a low-temperature regime. Independent plasma characterization was obtained using frequency domain interferometry diagnostic (FDI) that allows the interpretation of the absorption spectra in terms of spectral opacities. Assuming local thermodynamic equilibrium, spectral opacity calculations have been performed using the density and temperature inferred from the FDI diagnostic to compare to the measured absorption spectra. A good agreement is obtained when non-equilibrium effects due to non-stationary atomic physics are negligible at the x-ray probe time.

  1. Gas Electron Multiplier foil holes: a study of mechanical and deformation effects

    NASA Astrophysics Data System (ADS)

    Benussi, L.; Bianco, S.; Saviano, G.; Muhammad, S.; Piccolo, D.; Suhaj, A.; Sharma, A.; Caponero, M.; Passamonti, L.; Pierluigi, D.; Russo, A.; Lalli, A.; Valente, M.; Ferrini, M.; Langeslag, S. A. E.; Sgobba, S.; Aviles, I.; Magnani, A.; Vai, I.

    2016-08-01

    The GEM detectors will be installed at the Compact Muon Solenoid (CMS) experiment during Long Shutdown II of the LHC in 2018. The GEM foil is a basic part of the detector which consists of a composite material, i.e. polyimide coated with copper and perforated with a high density of micro holes. In this paper the results of the GEM foil material characterization are reported, and a campaign of tensile and holes deformation tests is performed. During the tests, the complex radiation environment at CMS is taken into account and samples are prepared accordingly to see the impacts of the radiation on the GEM foil, i.e. non-irradiated samples are used as the reference and compared with neutrons- and gamma- irradiated. These studies provide the information necessary to optimize the stress level without damaging the foil and holes during the detector assembly in which the GEM foils stack is stretched simultaneously to maintain the uniform gap among the foils in order to get the designed performance of the detector. Finally, an estimate of the Young's modulus of the GEM foil is provided by using the tensile test data.

  2. An Assessment of Gas Foil Bearing Scalability and the Potential Benefits to Civilian Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert J.

    2010-01-01

    Over the past several years the term oil-free turbomachinery has been used to describe a rotor support system for high speed turbomachinery that does not require oil for lubrication, damping, or cooling. The foundation technology for oil-free turbomachinery is the compliant foil bearing. This technology can replace the conventional rolling element bearings found in current engines. Two major benefits are realized with this technology. The primary benefit is the elimination of the oil lubrication system, accessory gearbox, tower shaft, and one turbine frame. These components account for 8 to 13 percent of the turbofan engine weight. The second benefit that compliant foil bearings offer to turbofan engines is the capability to operate at higher rotational speeds and shaft diameters. While traditional rolling element bearings have diminished life, reliability, and load capacity with increasing speeds, the foil bearing has a load capacity proportional to speed. The traditional applications for foil bearings have been in small, lightweight machines. However, recent advancements in the design and manufacturing of foil bearings have increased their potential size. An analysis, grounded in experimentally proven operation, is performed to assess the scalability of the modern foil bearing. This analysis was coupled to the requirements of civilian turbofan engines. The application of the foil bearing to larger, high bypass ratio engines nominally at the 120 kN (approx.25000 lb) thrust class has been examined. The application of this advanced technology to this system was found to reduce mission fuel burn by 3.05 percent.

  3. Aluminum plasmonic photocatalysis

    PubMed Central

    Hao, Qi; Wang, Chenxi; Huang, Hao; Li, Wan; Du, Deyang; Han, Di; Qiu, Teng; Chu, Paul K.

    2015-01-01

    The effectiveness of photocatalytic processes is dictated largely by plasmonic materials with the capability to enhance light absorption as well as the energy conversion efficiency. Herein, we demonstrate how to improve the plasmonic photocatalytic properties of TiO2/Al nano-void arrays by overlapping the localized surface plasmon resonance (LSPR) modes with the TiO2 band gap. The plasmonic TiO2/Al arrays exhibit superior photocatalytic activity boasting an enhancement of 7.2 folds. The underlying mechanisms concerning the radiative energy transfer and interface energy transfer processes are discussed. Both processes occur at the TiO2/Al interface and their contributions to photocatalysis are evaluated. The results are important to the optimization of aluminum plasmonic materials in photocatalytic applications. PMID:26497411

  4. Aluminum: Industry of the future

    SciTech Connect

    1998-11-01

    For over a century, the US aluminum industry has led the global market with advances in technology, product development, and marketing. Industry leaders recognize both the opportunities and challenges they face as they head into the 21st century, and that cooperative R and D is key to their success. In a unique partnership, aluminum industry leaders have teamed with the US Department of Energy`s Office of Industrial Technologies (OIT) to focus on innovative technologies that will help to strengthen the competitive position of the US aluminum industry and, at the same time, further important national goals. This industry-led partnership, the Aluminum Industry of the Future, promotes technologies that optimize the use of energy and materials in operations and reduce wastes and energy-related emissions. Led by The Aluminum Association, industry leaders began by developing a unified vision of future market, business, energy, and environmental goals. Their vision document, Partnerships for the Future, articulates a compelling vision for the next 20 years: to maintain and grow the aluminum industry through the manufacture and sale of competitively priced, socially desirable, and ecologically sustainable products. Continued global leadership in materials markets will require the combined resources of industry, universities, and government laboratories. By developing a unified vision, the aluminum industry has provided a framework for the next step in the Industries of the Future process, the development of a technology roadmap designed to facilitate cooperative R and D.

  5. Spray Rolling Aluminum Strip

    SciTech Connect

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  6. Performance variation due to stiffness in a tuna-inspired flexible foil model.

    PubMed

    Rosic, Mariel-Luisa N; Thornycroft, Patrick J M; Feilich, Kara L; Lucas, Kelsey N; Lauder, George V

    2017-01-17

    Tuna are fast, economical swimmers in part due to their stiff, high aspect ratio caudal fins and streamlined bodies. Previous studies using passive caudal fin models have suggested that while high aspect ratio tail shapes such as a tuna's generally perform well, tail performance cannot be determined from shape alone. In this study, we analyzed the swimming performance of tuna-tail-shaped hydrofoils of a wide range of stiffnesses, heave amplitudes, and frequencies to determine how stiffness and kinematics affect multiple swimming performance parameters for a single foil shape. We then compared the foil models' kinematics with published data from a live swimming tuna to determine how well the hydrofoil models could mimic fish kinematics. Foil kinematics over a wide range of motion programs generally showed a minimum lateral displacement at the narrowest part of the foil, and, immediately anterior to that, a local area of large lateral body displacement. These two kinematic patterns may enhance thrust in foils of intermediate stiffness. Stiffness and kinematics exhibited subtle interacting effects on hydrodynamic efficiency, with no one stiffness maximizing both thrust and efficiency. Foils of intermediate stiffnesses typically had the greatest coefficients of thrust at the highest heave amplitudes and frequencies. The comparison of foil kinematics with tuna kinematics showed that tuna motion is better approximated by a zero angle of attack foil motion program than by programs that do not incorporate pitch. These results indicate that open questions in biomechanics may be well served by foil models, given appropriate choice of model characteristics and control programs. Accurate replication of biological movements will require refinement of motion control programs and physical models, including the creation of models of variable stiffness.

  7. Mechanical design and vibro-acoustic testing of ultrathin carbon foils for a spacecraft instrument

    SciTech Connect

    Bernardin, John D; Baca, Allen G

    2009-01-01

    IBEX-Hi is an electrostatic analyzer spacecraft instrument designed to measure the energy and flux distribution of energetic neutral atoms (ENAs) emanating from the interaction zone between the Earth's solar system and the Milky Way galaxy. A key element to this electro-optic instrument is an array of fourteen carbon foils that are used to ionize the ENAs. The foils are comprised of an ultrathin (50-100 {angstrom} thick) layer of carbon suspended across the surface of an electroformed Nickel wire screen, which in turn is held taught by a metal frame holder. The electro formed orthogonal screen has square wire elements, 12.7 {micro}m thick, with a pitch of 131.1 wires/cm. Each foil holder has an open aperture approximately 5 cm by 2.5 cm. Designing and implementing foil holders with such a large surface area has not been attempted for spaceflight in the past and has proven to be extremely challenging. The delicate carbon foils are subject to fatigue failure from the large acoustic and vibration loads that they will be exposed to during launch of the spacecraft. This paper describes the evolution of the foil holder design from previous space instrument applications to a flight-like IBEX-Hi prototype. Vibro-acoustic qualification tests of the IBEX-Hi prototype instrument and the resulting failure of several foils are summarized. This is followed by a discussion of iterative foil holder design modifications and laser vibrometer modal testing to support future fatigue failure analyses, along with additional acoustic testing of the IBEX-Hi prototype instrument. The results of these design and testing activities are merged and the resulting flight-like foil holder assembly is proposed.

  8. [Microbiological corrosion of aluminum alloys].

    PubMed

    Smirnov, V F; Belov, D V; Sokolova, T N; Kuzina, O V; Kartashov, V R

    2008-01-01

    Biological corrosion of ADO quality aluminum and aluminum-based construction materials (alloys V65, D16, and D16T) was studied. Thirteen microscopic fungus species and six bacterial species proved to be able to attack aluminum and its alloys. It was found that biocorrosion of metals by microscopic fungi and bacteria was mediated by certain exometabolites. Experiments on biocorrosion of the materials by the microscopic fungus Alternaria alternata, the most active biodegrader, demonstrated that the micromycete attack started with the appearance of exudate with pH 8-9 on end faces of the samples.

  9. PREPARATION OF URANIUM-ALUMINUM ALLOYS

    DOEpatents

    Moore, R.H.

    1962-09-01

    A process is given for preparing uranium--aluminum alloys from a solution of uranium halide in an about equimolar molten alkali metal halide-- aluminum halide mixture and excess aluminum. The uranium halide is reduced and the uranium is alloyed with the excess aluminum. The alloy and salt are separated from each other. (AEC)

  10. Non-Chromate Aluminum Pretreatments, Phase 2

    DTIC Science & Technology

    2004-09-01

    September 2004 78 ALUMINUM AL2024-T3 ALUMINUM AL7075 -T6 PNL ID 4 Control 5...ALUMINUM - AL2024-T3 192 ALUMINUM - AL7075 -T6 112 Table 5.13: AMCOM – NAVAIR PANEL TEST MATRIX OCTOBER 2003 NCAP Phase II Interim Report

  11. Eddy current probe with foil sensor mounted on flexible probe tip and method of use

    DOEpatents

    Viertl, John R. M.; Lee, Martin K.

    2001-01-01

    A pair of copper coils are embedded in the foil strip. A first coil of the pair generates an electromagnetic field that induces eddy currents on the surface, and the second coil carries a current influenced by the eddy currents on the surface. The currents in the second coil are analyzed to obtain information on the surface eddy currents. An eddy current probe has a metal housing having a tip that is covered by a flexible conductive foil strip. The foil strip is mounted on a deformable nose at the probe tip so that the strip and coils will conform to the surface to which they are applied.

  12. Suppression of instability by double ablation in tungsten doped polyvinyl alcohol foils

    NASA Astrophysics Data System (ADS)

    Peedikakkandy, Leshma; Chaurasia, S.

    2012-07-01

    In Inertial fusion Energy (IFE) research stable acceleration of fusion targets is a significant problem due to hydrodynamic instabilities. This paper presents the results of the experiments done to investigate the effects of doping 20% of Tungsten (W) (by weight) in Polyvinyl Alcohol (PVA) polymer foils for suppression of instability during laser ablative acceleration. A 20J, 1.060μm, 900ps, Nd: Glass laser system with a focusable intensity of 3 to 9.6×1013W/cm2 was used in the experiment. It is observed that the doped PVA targets yielded stable and enhanced foil acceleration as compared to the undoped PVA foils.

  13. Structural changes on the surface of tungsten foils under uniaxial tension

    NASA Astrophysics Data System (ADS)

    Korsukov, V. E.; Knyazev, S. A.; Butenko, P. N.; Gilyarov, V. L.; Korsukova, M. M.; Nyapshaev, I. A.; Obidov, B. A.

    2017-02-01

    A change in the surface morphology of recrystallized tungsten foil under the effect of uniaxial tension in ultrahigh vacuum is studied by low-energy electron diffraction and atomic force microscopy. It is found by using low-energy electron diffraction that on the foil surface consisting of separate blocks with dominant face (112), there is a turn in orientation of the structural blocks. The analysis of the topograms of different areas of the side surface of a broken sample, obtained by atomic force microscopy, enabled the association of changes in the atomic structure of the surface layers of foil with a change in its relief by mechanical action.

  14. Interaction of solar wind ions with thin carbon foils: Calibration of time-of-flight spectrometers

    NASA Astrophysics Data System (ADS)

    Gonin, M.; Buergi, Alfred; Oetliker, M.; Bochsler, P.

    1992-11-01

    With the KAFKA (German acronym for carbon foils collisions analyzer) experiment, charge exchange, energy loss and angular scattering of solar wind ions in thin (1 to 10 microg/sq cm) carbon foils, are studied. Such foils are extensively used in time of flight mass spectrometry. So far, the properties of H, He, B, C, N, O, F, Ne, Na, Mg, Al, Si, S, Cl, Ar, K, Ti, Fe, and Ni and in the 0.5 to 5 keV/u energy range have been investigated.

  15. 75 FR 70689 - Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum-Greenwood Forge Division; Currently...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-18

    ... Employment and Training Administration Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum- Greenwood... Aluminum Fabricated Products, LLC, Kaiser Aluminum-Greenwood Forge Division, including on- site leased... are engaged in the production of aluminum alloy forgings. Information shows that on July 28,...

  16. Coating of Stainless- and Carbon-Steel Foil

    DTIC Science & Technology

    1951-12-01

    hot sulphuric acid pickling batch, slightly acid nickel sulphate flashing solution and a borax -soda ash neutralizer. 2. Coating Preparation Refractory...Aluminum Hydrate - 15.1 - - - - - - Vanadium Pentoxide (90%) - - 5 5 1.25 2.5 - - 3.5 Iron Oxide - - - 2 - - - - - Chromic Oxide .- 3.9 - - Boric Acid ...83 47.4 59.9 - - - Borax 23.80 21.0 - - 17.9 11.9 - - - Soda Ash 6.44 4.ŗ 5 5 6.1 5.8 - - - Soda Nitre 4.13 0 5 5 4.4 1.6 - - - Fluorspar 3.71 3.2

  17. Electrolyte treatment for aluminum reduction

    DOEpatents

    Brown, Craig W.; Brooks, Richard J.; Frizzle, Patrick B.; Juric, Drago D.

    2002-01-01

    A method of treating an electrolyte for use in the electrolytic reduction of alumina to aluminum employing an anode and a cathode, the alumina dissolved in the electrolyte, the treating improving wetting of the cathode with molten aluminum during electrolysis. The method comprises the steps of providing a molten electrolyte comprised of ALF.sub.3 and at least one salt selected from the group consisting of NaF, KF and LiF, and treating the electrolyte by providing therein 0.004 to 0.2 wt. % of a transition metal or transition metal compound for improved wettability of the cathode with molten aluminum during subsequent electrolysis to reduce alumina to aluminum.

  18. Ballistic Evaluation of 7085 Aluminum

    DTIC Science & Technology

    2012-03-01

    tempers of aluminum alloy (AA) 7085 produced by Alcoa. The tempers included a high-strength variant, 7085-T7E01, for utilization as an appliqué against...temper. The V50 was then compared to other ballistic-grade aluminum alloys , namely AA7039 and AA2139. The results of these tests were used to derive... alloy 7085-T7E01 and 7085-T7E02. ......................................1 Table 2. Chemistry of AAs, weight-percent ranges

  19. Chrome - Free Aluminum Coating System

    NASA Technical Reports Server (NTRS)

    Bailey, John H.; Gugel, Jeffrey D.

    2010-01-01

    This slide presentation concerns the program to qualify a chrome free coating for aluminum. The program was required due to findings by OSHA and EPA, that hexavalent chromium, used to mitigate corrosion in aerospace aluminum alloys, poses hazards for personnel. This qualification consisted of over 4,000 tests. The tests revealed that a move away from Cr+6, required a system rather than individual components and that the maximum corrosion protection required pretreatment, primer and topcoat.

  20. Static and dynamic performances of refrigerant-lubricated foil bearings

    NASA Astrophysics Data System (ADS)

    Bouchehit, B.; Bou-Saïd, B.; Garcia, M.

    2016-08-01

    Gas bearings are successfully used over a large panel of turbo-machineries. Some of these systems run in controlled environments such as refrigerating gas. We present in this paper a theoretical and numerical model which consider the vapor/liquid lubricant transition, the laminar/turbulent flow transition and both temperature and viscosity 3D variations in the fluid and the solids for both static and dynamic situations. The foil deflection is considered using the Heshmat's approach. This model involves: the resolution of the generalized Reynolds equation for compressible fluids with 3D variable viscosity, the description of the turbulence effects by the phenomenological approach of Elrod, using a 3D eddy viscosity field, the resolution of a non-linear equation of state for the lubricant, able to describe the vapor/liquid transition and a local thermal approach to obtain a 3D estimation of the fluid temperature, thanks to the thin-film energy equation and an actualisation of the film thickness. The thermal effects in solids are also taken into account. Both static and dynamic behaviours of GFBs are analysed.

  1. Characterization of AN Actively Cooled Metal Foil Thermal Radiation Shield

    NASA Astrophysics Data System (ADS)

    Feller, J. R.; Kashani, A.; Helvensteijn, B. P. M.; Salerno, L. J.

    2010-04-01

    Zero boil-off (ZBO) or reduced boil-off (RBO) systems that involve active cooling of large cryogenic propellant tanks will most likely be required for future space exploration missions. For liquid oxygen or methane, such systems could be implemented using existing high technology readiness level (TRL) cryocoolers. However, for liquid hydrogen temperatures (˜20 K) no such coolers exist. In order to partially circumvent this technology gap, the concept of broad area cooling (BAC) has been developed, whereby a low mass thermal radiation shield could be maintained at temperatures around 100 K by steady circulation of cold pressurized gas through a network of narrow tubes. By this method it is possible to dramatically reduce the radiative heat leak to the 20 K tank. A series of experiments, designed to investigate the heat transfer capabilities of BAC systems, have been conducted at NASA Ames Research Center (ARC). Results of the final experiment in this series, investigating heat transfer from a metal foil film to a distributed cooling line, are presented here.

  2. Silicon oxide permeation barrier coating of PET bottles and foils

    NASA Astrophysics Data System (ADS)

    Steves, Simon; Deilmann, Michael; Awakowicz, Peter

    2009-10-01

    Modern packaging materials such as polyethylene terephthalate (PET) have displaced established materials in many areas of food and beverage packaging. Plastic packing materials offer are various advantages concerning production and handling. PET bottles for instance are non-breakable and lightweight compared to glass and metal containers. However, PET offers poor barrier properties against gas permeation. Therefore, the shelf live of packaged food is reduced. Permeation of gases can be reduced by depositing transparent plasma polymerized silicon oxide (SiOx) barrier coatings. A microwave (2.45 GHz) driven low pressure plasma reactor is developed based on a modified Plasmaline antenna to treat PET foils or bottles. To increase the barrier properties of the coatings furthermore a RF substrate bias (13.56 MHz) is applied. The composition of the coatings is analyzed by means of Fourier transform infrared (FTIR) spectroscopy regarding carbon and hydrogen content. Influence of gas phase composition and substrate bias on chemical composition of the coatings is discussed. A strong relation between barrier properties and film composition is found: good oxygen barriers are observed as carbon content is reduced and films become quartz-like. Regarding oxygen permeation a barrier improvement factor (BIF) of 70 is achieved.

  3. CHARACTERIZATION OF AN ACTIVELY COOLED METAL FOIL THERMAL RADIATION SHIELD

    SciTech Connect

    Feller, J. R.; Salerno, L. J.; Kashani, A.; Helvensteijn, B. P. M.

    2010-04-09

    Zero boil-off (ZBO) or reduced boil-off (RBO) systems that involve active cooling of large cryogenic propellant tanks will most likely be required for future space exploration missions. For liquid oxygen or methane, such systems could be implemented using existing high technology readiness level (TRL) cryocoolers. However, for liquid hydrogen temperatures (approx20 K) no such coolers exist. In order to partially circumvent this technology gap, the concept of broad area cooling (BAC) has been developed, whereby a low mass thermal radiation shield could be maintained at temperatures around 100 K by steady circulation of cold pressurized gas through a network of narrow tubes. By this method it is possible to dramatically reduce the radiative heat leak to the 20 K tank. A series of experiments, designed to investigate the heat transfer capabilities of BAC systems, have been conducted at NASA Ames Research Center (ARC). Results of the final experiment in this series, investigating heat transfer from a metal foil film to a distributed cooling line, are presented here.

  4. In Situ Graphene Growth Dynamics on Polycrystalline Catalyst Foils

    PubMed Central

    2016-01-01

    The dynamics of graphene growth on polycrystalline Pt foils during chemical vapor deposition (CVD) are investigated using in situ scanning electron microscopy and complementary structural characterization of the catalyst with electron backscatter diffraction. A general growth model is outlined that considers precursor dissociation, mass transport, and attachment to the edge of a growing domain. We thereby analyze graphene growth dynamics at different length scales and reveal that the rate-limiting step varies throughout the process and across different regions of the catalyst surface, including different facets of an individual graphene domain. The facets that define the domain shapes lie normal to slow growth directions, which are determined by the interfacial mobility when attachment to domain edges is rate-limiting, as well as anisotropy in surface diffusion as diffusion becomes rate-limiting. Our observations and analysis thus reveal that the structure of CVD graphene films is intimately linked to that of the underlying polycrystalline catalyst, with both interfacial mobility and diffusional anisotropy depending on the presence of step edges and grain boundaries. The growth model developed serves as a general framework for understanding and optimizing the growth of 2D materials on polycrystalline catalysts. PMID:27576749

  5. Calibration of thin-foil manganin gauge in ALOX material

    NASA Astrophysics Data System (ADS)

    Benham, R. A.; Weirick, L. J.; Lee, L. M.

    The purpose of this program was to develop a calibration curve (stress as a function of change in gauge resistance/gauge resistance) and to obtain gauge repeatability data for Micro-Measurements stripped manganin thin-foiled gauges up to 6.1 GPa in ALOX (42% by volume alumina in Epon 828 epoxy) material. A light-gas gun was used to drive an ALOX impactor into the ALOX target containing four gauges in a centered diamond arrangement. Tilt and velocity of the impactor were measured along with the gauge outputs. Impact stresses from 0.5 to 6.1 GPa were selected in increments of 0.7 GPa with duplicate tests done at 0.5, 3.3 and 6.1 GPa. A total of twelve tests were conducted using ALOX. Three initial tests were done using polymethyl methacrylate (PMMA) as the impactor and target at an impact pressure of 3.0 GPa for comparison of gauge output with analysis and literature values. The installed gauge, stripped of its backing, has a nominal thickness of 5 (micro)m. The thin gauge and high speed instrumentation allowed higher time resolution measurements than can be obtained with manganin wire.

  6. Optomechanics of Single Aluminum Nanodisks.

    PubMed

    Su, Man-Nung; Dongare, Pratiksha D; Chakraborty, Debadi; Zhang, Yue; Yi, Chongyue; Wen, Fangfang; Chang, Wei-Shun; Nordlander, Peter; Sader, John E; Halas, Naomi J; Link, Stephan

    2017-04-12

    Aluminum nanostructures support tunable surface plasmon resonances and have become an alternative to gold nanoparticles. Whereas gold is the most-studied plasmonic material, aluminum has the advantage of high earth abundance and hence low cost. In addition to understanding the size and shape tunability of the plasmon resonance, the fundamental relaxation processes in aluminum nanostructures after photoexcitation must be understood to take full advantage of applications such as photocatalysis and photodetection. In this work, we investigate the relaxation following ultrafast pulsed excitation and the launching of acoustic vibrations in individual aluminum nanodisks, using single-particle transient extinction spectroscopy. We find that the transient extinction signal can be assigned to a thermal relaxation of the photoexcited electrons and phonons. The ultrafast heating-induced launching of in-plane acoustic vibrations reveals moderate binding to the glass substrate and is affected by the native aluminum oxide layer. Finally, we compare the behavior of aluminum nanodisks to that of similarly prepared and sized gold nanodisks.

  7. A Virtual Aluminum Reduction Cell

    NASA Astrophysics Data System (ADS)

    Zhang, Hongliang; Zhou, Chenn Q.; Wu, Bing; Li, Jie

    2013-11-01

    The most important component in the aluminum industry is the aluminum reduction cell; it has received considerable interests and resources to conduct research to improve its productivity and energy efficiency. The current study focused on the integration of numerical simulation data and virtual reality technology to create a scientifically and practically realistic virtual aluminum reduction cell by presenting complex cell structures and physical-chemical phenomena. The multiphysical field simulation models were first built and solved in ANSYS software (ANSYS Inc., Canonsburg, PA, USA). Then, the methodology of combining the simulation results with virtual reality was introduced, and a virtual aluminum reduction cell was created. The demonstration showed that a computer-based world could be created in which people who are not analysis experts can see the detailed cell structure in a context that they can understand easily. With the application of the virtual aluminum reduction cell, even people who are familiar with aluminum reduction cell operations can gain insights that make it possible to understand the root causes of observed problems and plan design changes in much less time.

  8. Self-propelled swimming of a flexible plunging foil near a solid wall.

    PubMed

    Dai, Longzhen; He, Guowei; Zhang, Xing

    2016-07-05

    Numerical simulations are conducted to investigate the influences of a solid wall on the self-propelled swimming of a flexible plunging foil. It is found that the presence of a solid wall enhances the cruising speed, with the cost of increasing input power. Rigid foil can achieve high percentage increase in cruising speed when swimming near a solid wall, but the propulsive efficiency may be reduced. Foils with some flexibility can enjoy the enhancements in both cruising speed and propulsive efficiency. Another advantage of the flexible foils in near-wall swimming is that smaller averaged lateral forces are produced. The effects of wall confinement on the wake structure and the vortex dynamics are also studied in this paper. The results obtained in this study shed some light on the unsteady wall effect experienced by aquatic animals and also inform the design of bio-mimetic underwater vehicles which are capable of exploiting the wall effect.

  9. A free-standing thin foil bolometer for measuring soft x-ray fluence.

    PubMed

    Hu, Qingyuan; Ning, Jiamin; Ye, Fan; Meng, Shijian; Xu, Rongkun; Yang, Jianlun; Chu, Yanyun; Qin, Yi; Fu, Yuecheng; Chen, Faxin; Xu, Zeping

    2016-10-01

    A free-standing thin foil bolometer for measuring soft x-ray fluence in z-pinch experiments is developed. For the first time, we present the determination of its sensitivity by different methods. The results showed great consistency for the different methods, which confirms the validity of the sensitivity and provides confidence for its application in z-pinch experiments. It should be highlighted that the sensitivity of a free-standing foil bolometer could be calibrated directly using Joule heating without any corrections that will be necessary for a foil bolometer with substrate because of heat loss. The difference of the waveforms between the free-standing foil bolometer and that with substrate is obvious. It reveals that the heat loss to the substrate should be considered for the latter in despite of the short x-ray pulse when the peak value is used to deduce the total deposited energy. The quantitative influence is analyzed through a detailed simulation.

  10. Use of Soller slits to remove reference foil fluorescence from transmission spectra.

    PubMed

    Tse, Justin J; George, Graham N; Pickering, Ingrid J

    2011-05-01

    Measurement of X-ray absorption spectroscopy (XAS) in transmission is the method of choice for strong or concentrated samples. In a typical XAS experiment above 5 keV the sample is placed between the first (I(0)) and second (I(1)) ion chambers and a standard foil is placed between the second (I(1)) and third (I(2)) ion chambers for simultaneous calibration of energy during sample analysis. However, some fluorescence from the foil may be registered in I(1), causing anomalies in the transmission signal of the sample, especially when the sample edge jump is relatively small. To remedy this, Soller slits were constructed and placed between the foil and I(1) to minimize back-fluorescence from the foil. A comparison of blank and standard samples, measured with or without Soller slits or under a worst-case scenario, demonstrates the advantages of Soller slits when analyzing weak signal samples via transmission XAS.

  11. One-step synthesis of TiO₂ nanorod arrays on Ti foil for supercapacitor application.

    PubMed

    Zheng, Zhi; Chen, Jiajun; Yoshida, Ryuji; Gao, Xiang; Tarr, Kayla; Ikuhara, Yumi H; Zhou, Weilie

    2014-10-31

    Titanium dioxide (TiO2) nanorod arrays grown directly on Ti metal foil were prepared by a facile one-step hydrothermal method, in which the Ti foil serves as both substrate and precursor. The nanorods are tetragonal rutile single crystal with growth orientation along the [001] direction. The electrochemical properties of the TiO2 nanorod arrays were systematically investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy using a three-electrode system. As a result, the TiO2 nanorod arrays exhibit good areal specific capacitance and excellent cyclic stability by retaining more than 98% of the initial specific capacitance after 1000 cycles. In addition, a good flexibility of the Ti foil with TiO2 nanorod arrays was demonstrated by the stable electrochemical performance under different bending angles, which indicates that TiO2 nanorod arrays grown on Ti foil could be a promising electrode material for flexible supercapacitor application.

  12. Process for forming a nickel foil with controlled and predetermined permeability to hydrogen

    DOEpatents

    Engelhaupt, Darell E.

    1981-09-22

    The present invention provides a novel process for forming a nickel foil having a controlled and predetermined hydrogen permeability. This process includes the steps of passing a nickel plating bath through a suitable cation exchange resin to provide a purified nickel plating bath free of copper and gold cations, immersing a nickel anode and a suitable cathode in the purified nickel plating bath containing a selected concentration of an organic sulfonic acid such as a napthalene-trisulfonic acid, electrodepositing a nickel layer having the thickness of a foil onto the cathode, and separating the nickel layer from the cathode to provide a nickel foil. The anode is a readily-corrodible nickel anode. The present invention also provides a novel nickel foil having a greater hydrogen permeability than palladium at room temperature.

  13. Compositional Determination of Surviving Material in Stardust Analog Al Foil Craters

    NASA Astrophysics Data System (ADS)

    Croat, T. K.; Haas, B. A.; Floss, C.; Burchell, M. J.

    2015-07-01

    Surviving material is commonly detected in Stardust Al foil analog craters created by impact of primitive meteorite matrix, and semi-quantitative compositions can be determined that can guide subsequent FIB-TEM studies focused on refractory phases.

  14. Magnetic Fano resonances by design in symmetry broken THz meta-foils

    NASA Astrophysics Data System (ADS)

    Wu, Jianfeng; Moser, Herbert O.; Li, Rujiang; Yang, Yihao; Jing, Liqiao; Chen, Hongsheng; Breese, Mark B. H.

    2017-02-01

    Magnetic Fano resonances in there-dimensional symmetry broken meta-foils at THz frequencies are theoretically and experimentally studied. Sharp Fano resonances occur due to the interference between different resonances and can be designed by choosing geometric parameters of the meta-foil. At the Fano resonances, the meta-foil supports antisymmetric modes, whereas, at the main resonance, only a symmetric mode exists. The meta-foil is left-handed at the Fano resonances and shows sharp peaks of the real part of the refractive index in transmission with small effective losses opening a way to very sensitive high-speed sensing of dielectric changes in the surrounding media and of mechanical configuration.

  15. Magnetic Fano resonances by design in symmetry broken THz meta-foils

    PubMed Central

    Wu, Jianfeng; Moser, Herbert O.; Li, Rujiang; Yang, Yihao; Jing, Liqiao; Chen, Hongsheng; Breese, Mark B. H.

    2017-01-01

    Magnetic Fano resonances in there-dimensional symmetry broken meta-foils at THz frequencies are theoretically and experimentally studied. Sharp Fano resonances occur due to the interference between different resonances and can be designed by choosing geometric parameters of the meta-foil. At the Fano resonances, the meta-foil supports antisymmetric modes, whereas, at the main resonance, only a symmetric mode exists. The meta-foil is left-handed at the Fano resonances and shows sharp peaks of the real part of the refractive index in transmission with small effective losses opening a way to very sensitive high-speed sensing of dielectric changes in the surrounding media and of mechanical configuration. PMID:28150797

  16. Active control of a cylinder wake flow by using a streamwise oscillating foil

    NASA Astrophysics Data System (ADS)

    Bao, Y.; Tao, J.

    2013-05-01

    In this study, numerical experiments are carried out to control the vortex shedding of a circular cylinder by utilizing an oscillating foil. The thin foil of elliptic shape undergoes prescribed harmonic oscillations in the streamwise direction in the near wake region. This simplified model is intended to study how wake dynamics are modified via localized wake disturbance, and then to stabilize the global wake instability. The results show that, at proper gap spacing, the oscillating foil can completely suppress the wake unsteadiness and recover the recirculating bubble type flow. The global instability suppression is then established on the imposition of local symmetry into the reversed flow behind the cylinder. It is revealed that the dynamic interaction between the main shears layer and oscillatory boundary layers is responsible for the wake stabilization mechanism. In addition, the kinematic/dynamic parameters related to foil motions and flow properties are widely discussed to reveal their effects on the performance of wake stabilization and drag reduction.

  17. Note: Radial-thrust combo metal mesh foil bearing for microturbomachinery.

    PubMed

    Park, Cheol Hoon; Choi, Sang Kyu; Hong, Doo Euy; Yoon, Tae Gwang; Lee, Sung Hwi

    2013-10-01

    This Note proposes a novel radial-thrust combo metal mesh foil bearing (MMFB). Although MMFBs have advantages such as higher stiffness and damping over conventional air foil bearings, studies related to MMFBs have been limited to radial MMFBs. The novel combo MMFB is composed of a radial top foil, thrust top foils, and a ring-shaped metal mesh damper--fabricated by compressing a copper wire mesh--with metal mesh thrust pads for the thrust bearing at both side faces. In this study, the combo MMFB was fabricated in half-split type to support the rotor for a micro gas turbine generator. The manufacture and assembly process for the half-split-type combo MMFB is presented. In addition, to verify the proposed combo MMFB, motoring test results up to 250,000 rpm and axial displacements as a function of rotational speed are presented.

  18. LANL Experience Rolling Zr-Clad LEU-10Mo Foils for AFIP-7

    SciTech Connect

    Hammon, Duncan L.; Clarke, Kester D.; Alexander, David J.; Kennedy, Patrick K.; Edwards, Randall L.; Duffield, Andrew N.; Dombrowski, David E.

    2015-05-29

    The cleaning, canning, rolling and final trimming of Low Enriched Uranium-10 wt. pct. Molybdenum (LEU-10Mo) foils for ATR (Advanced Test Reactor) fuel plates to be used in the AFIP-7 (ATR Full Size Plate In Center Flux Trap Position) experiments are summarized. Six Zr-clad foils were produced from two LEU-10Mo castings supplied to Los Alamos National Laboratory (LANL) by Y-12 National Security Complex. Details of cleaning and canning procedures are provided. Hot- and cold-rolling results are presented, including rolling schedules, images of foils in-process, metallography and local compositions of regions of interest, and details of final foil dimensions and process yield. This report was compiled from the slides for the presentation of the same name given by Duncan Hammon on May 12, 2011 at the AFIP-7 Lessons Learned meeting in Salt Lake City, UT, with Los Alamos National Laboratory document number LA-UR 11-02898.

  19. Monte carlo simulation of positron induced secondary electrons in thin carbon foils

    NASA Astrophysics Data System (ADS)

    Cai, L. H.; Yang, B.; Ling, C. C.; Beling, C. D.; Fung, S.

    2011-01-01

    Emission of secondary electrons induced by the passage of low energy positrons through thin carbon foils was studied by the Monte Carlo method. The positron and electron elastic cross sections were calculated by partial wave analysis. The inelastic positron-valence-electron was described by the energy loss function obtained from dielectric theory. The positron-core-electron interaction was modelled by the Gryzinski's excitation function. Positron transport inside the carbon foil was simulated in detail. Secondary electrons created by positrons and high energy secondary electrons through inelastic interactions were tracked through the foil. The positron transmission coefficient and secondary electron yielded in forward and backward geometry are calculated and dependences on positron energy and carbon foil thickness are discussed.

  20. The possibility of using platinum foils with a rippled surface as diffraction gratings

    NASA Astrophysics Data System (ADS)

    Korsukov, V. E.; Ankudinov, A. V.; Butenko, P. N.; Knyazev, S. A.; Korsukova, M. M.; Obidov, B. A.; Shcherbakov, I. P.

    2014-09-01

    The atomic structure and surface relief of thin cold-rolled platinum foils upon recrystallization annealing and loading under ultrahigh vacuum conditions have been studied by low energy electron diffraction (LEED), atomic force microscopy (AFM), and scanning tunneling microscopy (STM). The surface of samples upon high-temperature annealing and subsequent uniaxial extension of recrystallized Pt foils represents a fractal structure of unidirectional ripples on various spatial scales. The total fractal dimension of this surface is D GW = 2.3, while the fractal dimensions along and across ripples are D ‖ ≈ 1 and D ⊥ ≈ 1.3, respectively. The optical spectra of a halogen lamp and a PRK-2 mercury lamp were recorded using these rippled Pt foils as reflection diffraction gratings. It is shown that Pt foils with this surface relief can be used as reflection diffraction gratings for electromagnetic radiation in a broad spectral range.

  1. Method of using deuterium-cluster foils for an intense pulsed neutron source

    DOEpatents

    Miley, George H.; Yang, Xiaoling

    2013-09-03

    A method is provided for producing neutrons, comprising: providing a converter foil comprising deuterium clusters; focusing a laser on the foil with power and energy sufficient to cause deuteron ions to separate from the foil; and striking a surface of a target with the deuteron ions from the converter foil with energy sufficient to cause neutron production by a reaction selected from the group consisting of D-D fusion, D-T fusion, D-metal nuclear spallation, and p-metal. A further method is provided for assembling a plurality of target assemblies for a target injector to be used in the previously mentioned manner. A further method is provided for producing neutrons, comprising: splitting a laser beam into a first beam and a second beam; striking a first surface of a target with the first beam, and an opposite second surface of the target with the second beam with energy sufficient to cause neutron production.

  2. Polarization and collision-induced coherence in the beam-foil light source

    NASA Technical Reports Server (NTRS)

    Liu, C. H.; Bashkin, S.; Church, D. A.

    1974-01-01

    Monatomic systems were excited by the beam-foil method in order to re-examine the possibility that a particular magnetic substate was preferentially populated. O II, Ar II and He I levels were used. The results reveal that: (1) with a tilted foil substantial polarization (up to 15%) may be achieved, (2) the polarization is due to the foil, (3) the foil induces coherence among Zeeman substates with the appearance of quantum beats among these substates and that their coherence is due to the externally applied magnetic field perpendicular to the beam direction, and (4) the angular momentum of the emitted photon is perpendicular to the ion velocity. The possibility for detecting separate effects of alignment and polarization is noted.

  3. Characterization and anticorrosion properties of carbon nanotubes directly synthesized on Ni foil using ethanol

    NASA Astrophysics Data System (ADS)

    Jeong, Namjo; Jwa, Eunjin; Kim, Chansoo; Hwang, Kyo Sik; Park, Soon-cheol; Jang, Moon Suk

    2016-07-01

    In this work, we describe the direct growth of carbon nanofilaments by the catalytic decomposition of ethanol on untreated polycrystalline Ni foil. Our work focuses on the effects of synthesis conditions on the growth of the carbon nanofilaments and their growth mechanism. Direct growth of carbon nanotubes (CNTs) is more favorable on lower-purity Ni foil. The highest yield was obtained at approximately 750 °C. The average diameter of the CNTs was approximately 20-30 nm. Raman spectra revealed that the increase of H2 concentration in the carrier gas and synthesis temperature induced the growth of better-graphitized CNTs. Additionally, we investigated the anticorrosion properties of as-prepared products under simulated seawater conditions. The corrosion rate of the CNT/Ni foil system was maximally 50-60 times slower than that of the as-received Ni foil, indicating that the CNT coating may be a good candidate for corrosion inhibition.

  4. A free-standing thin foil bolometer for measuring soft x-ray fluence

    NASA Astrophysics Data System (ADS)

    Hu, Qingyuan; Ning, Jiamin; Ye, Fan; Meng, Shijian; Xu, Rongkun; Yang, Jianlun; Chu, Yanyun; Qin, Yi; Fu, Yuecheng; Chen, Faxin; Xu, Zeping

    2016-10-01

    A free-standing thin foil bolometer for measuring soft x-ray fluence in z-pinch experiments is developed. For the first time, we present the determination of its sensitivity by different methods. The results showed great consistency for the different methods, which confirms the validity of the sensitivity and provides confidence for its application in z-pinch experiments. It should be highlighted that the sensitivity of a free-standing foil bolometer could be calibrated directly using Joule heating without any corrections that will be necessary for a foil bolometer with substrate because of heat loss. The difference of the waveforms between the free-standing foil bolometer and that with substrate is obvious. It reveals that the heat loss to the substrate should be considered for the latter in despite of the short x-ray pulse when the peak value is used to deduce the total deposited energy. The quantitative influence is analyzed through a detailed simulation.

  5. Interpretation in Sweden.

    ERIC Educational Resources Information Center

    Hultman, Sven-G.

    1987-01-01

    Describes some of the interpretive developments underway in Sweden. Discusses some programs in both natural and cultural interpretation. Calls for increasing the purpose and content of heritage preservation and conservation to the general public. (TW)

  6. U-interpreter

    SciTech Connect

    Arvind; Gostelow, K.P.

    1982-02-01

    The author argues that by giving a unique name to every activity generated during a computation, the u-interpreter can provide greater concurrency in the interpretation of data flow graphs. 19 references.

  7. Method to Increase Performance of Foil Bearings Through Passive Thermal Management

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert

    2013-01-01

    This invention is a new approach to designing foil bearings to increase their load capacity and improve their reliability through passive thermal management. In the present case, the bearing is designed in such a way as to prevent the carryover of lubricant from the exit of one sector to the inlet of the ensuing sector of the foil bearing. When such passive thermal management techniques are used, bearing load capacity is improved by multiples, and reliability is enhanced when compared to current foil bearings. This concept has recently been tested and validated, and shows that load capacity performance of foil bearings can be improved by a factor of two at relatively low speeds with potentially greater relative improvements at higher speeds. Such improvements in performance with respect to speed are typical of foil bearings. Additionally, operation of these newly conceived bearings shows much more reliability and repeatable performance. This trait can be exploited in machine design to enhance safety, reliability, and overall performance. Finally, lower frictional torque has been demonstrated when operating at lower (non-load capacity) loads, thus providing another improvement above the current state of the art. The objective of the invention is to incorporate features into a foil bearing that both enhance passive thermal management and temperature control, while at the same time improve the hydrodynamic (load capacity) performance of the foil bearing. Foil bearings are unique antifriction devices that can utilize the working fluid of a machine as a lubricant (typically air for turbines and motors, liquids for pumps), and as a coolant to remove excess energy due to frictional heating. The current state of the art of foil bearings utilizes forced cooling of the bearing and shaft, which represents poor efficiency and poor reliability. This invention embodies features that utilize the bearing geometry in such a manner as to both support load and provide an inherent and

  8. Layered structure in the interaction of thin foil with two laser pulses

    SciTech Connect

    Yu, Yahong; Shen, Baifei E-mail: jill@siom.ac.cn; Yu, Wei; Wang, Wenpeng; Zhang, Xiaomei; Ji, Liangliang E-mail: jill@siom.ac.cn; Zhao, Xueyan; Wang, Xiaofeng; Yi, Longqing; Shi, Yin; Xu, Tongjun; Zhang, Lingang; Wen, Meng

    2014-02-15

    An interesting layered structure of multiple high density layers are formed when two counter-propagating circularly polarized laser pulses with the same polarization direction irradiate on an ultra-thin foil. This structure changes periodically. For light atoms most of which electrons may be fully ionized, this layered structure can keep for dozens of laser periods after the laser-foil interaction. This interesting structure may have potential applications.

  9. A review of progress and challenges in flapping foil power generation

    NASA Astrophysics Data System (ADS)

    Young, John; Lai, Joseph C. S.; Platzer, Max F.

    2014-05-01

    Power may be extracted from a flowing fluid in a variety of ways. Turbines using one or more oscillating foils are under increasingly active investigation, as an alternative to rotary wind turbines and river, oceanic and tidal current water turbines, although industrial development is at a very nascent stage. Such flapping foil turbines promise some key potential advantages, including lower foil velocities (and hence lower noise and wildlife impact), and more effective small-scale and shallow water operation. The role of a number of parameters is investigated, including foil kinematics (modes, frequencies, amplitudes and time histories of motion), foil and system geometry (shape, configuration and structural flexibility), and flow physics effects (Reynolds number and turbulence, shear flows and ground effect). Details of the kinematics are shown to have the single largest influence on power output and efficiency (measured as the ratio of power output to that available and accessible in the fluid stream). The highest levels of power and efficiency are associated with very large foil pitch angles (upwards of 70°) and angles of attack (30-40°), such that the flow is massively separated for much of the flapping cycle, in contrast to rotary turbines which rely on attached flow over as much of the rotor disk as possible. This leads to leading edge vortices comparable in size to the foil chord, and the evolution and interaction of these vortices with the foil as it moves play a central role in determining performance. The other parameters also influence the vortex behaviour, but in general to a lesser degree. Numerous gaps in the research literature and outstanding issues are highlighted.

  10. Study of the strata formation during the explosion of foils in vacuum

    NASA Astrophysics Data System (ADS)

    Zhigalin, A. S.; Rousskikh, A. G.; Oreshkin, V. I.; Chaikovsky, S. A.; Ratakhin, N. A.; Khishchenko, K. V.; Baksht, R. B.

    2015-11-01

    The formation of the strata during fast explosion of metal foils at current densities of 0.1 GA/cm2 has been studied experimentally. To observe the strata, the soft x-ray radiation generated by an X-pinch was used. The study of the process of stratification during the foil explosion was carried out with a setup consisting of three generators. One of the generators (WEG-2), was operated to initiate the explosion of the foils, while the others (XPG radiographs) were used for diagnostics. The generator WEG-2 has the capacitance of 250 nF, the charge voltage of 20 kV, and the current rate of 16 A/ns. The radiographs XPG have the capacitance of 1 μF, the charge voltage of 43 kV, the current of 300 kA, and the current rise time of 180 ns. X-pinch produced by four Mo wires was a load for the radiographs. The delay between the operation of the WEG-2 and XPG generators was set using a DPG trigger pulse generator. We performed the experiments with the Al and Cu foils. The length of foil was 2 cm, the foil width was 1 mm, and the foil thickness was 6 μm. It has been revealed that strata were formed early in the explosion, i.e. at the stage when the metal melted. Analysis of the experimental results suggests that the most probable reason for the stratification is the thermal instability developing because of the increase in resistivity of the foil metal with temperature.

  11. Conceptual Design and Feasibility of Foil Bearings for Rotorcraft Engines: Hot Core Bearings

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.

    2007-01-01

    Recent developments in gas foil bearing technology have led to numerous advanced high-speed rotating system concepts, many of which have become either commercial products or experimental test articles. Examples include oil-free microturbines, motors, generators and turbochargers. The driving forces for integrating gas foil bearings into these high-speed systems are the benefits promised by removing the oil lubrication system. Elimination of the oil system leads to reduced emissions, increased reliability, and decreased maintenance costs. Another benefit is reduced power plant weight. For rotorcraft applications, this would be a major advantage, as every pound removed from the propulsion system results in a payload benefit.. Implementing foil gas bearings throughout a rotorcraft gas turbine engine is an important long-term goal that requires overcoming numerous technological hurdles. Adequate thrust bearing load capacity and potentially large gearbox applied radial loads are among them. However, by replacing the turbine end, or hot section, rolling element bearing with a gas foil bearing many of the above benefits can be realized. To this end, engine manufacturers are beginning to explore the possibilities of hot section gas foil bearings in propulsion engines. This overview presents a logical follow-on activity by analyzing a conceptual rotorcraft engine to determine the feasibility of a foil bearing supported core. Using a combination of rotordynamic analyses and a load capacity model, it is shown to be reasonable to consider a gas foil bearing core section. In addition, system level foil bearing testing capabilities at NASA Glenn Research Center are presented along with analysis work being conducted under NRA Cooperative Agreements.

  12. Large-area thin self-supporting carbon foils with MgO coatings

    NASA Astrophysics Data System (ADS)

    Stolarz, Anna; Maier-Komor, Peter

    2002-03-01

    Large area self-supporting carbon foils in the thickness of range of 8-22 μg/cm 2, coated with approximately 4 μg/cm 2 MgO have been prepared by e-gun evaporation. They were mounted on frames with apertures of 130 cm 2. Problems related to the parting agent preparation, floating procedure, and mounting onto frames are discussed. Special precautions necessary to avoid damage during foil drying, storage and transportation are suggested.

  13. Co-Rolled U10Mo/Zirconium-Barrier-Layer Monolithic Fuel Foil Fabrication Process

    SciTech Connect

    G. A. Moore; M. C. Marshall

    2010-01-01

    Integral to the current UMo fuel foil processing scheme being developed at Idaho National Laboratory (INL) is the incorporation of a zirconium barrier layer for the purpose of controlling UMo-Al interdiffusion at the fuel-meat/cladding interface. A hot “co-rolling” process is employed to establish a ~25-µm-thick zirconium barrier layer on each face of the ~0.3-mm-thick U10Mo fuel foil.

  14. Modeling the transmission of beta rays through thin foils in planar geometry.

    PubMed

    Stanga, D; De Felice, P; Keightley, J; Capogni, M; Ionescu, E

    2016-01-01

    This paper is concerned with the modeling of the transmission of beta rays through thin foils in planar geometry based on the plane source concept, using Monte Carlo simulation of electron transport and least squares fitting. Applications of modeling results for calculating the efficiency of large-area beta sources, transmission coefficient of beta rays through thin foils and the beta detection efficiency of large-area detectors used in surface contamination measurements are also presented.

  15. Preparation and investigation of diamond-like carbon stripper foils by filtered cathodic vacuum arc

    NASA Astrophysics Data System (ADS)

    Fan, Qiwen; Du, Yinghui; Zhang, Rong; Xu, Guoji

    2013-04-01

    Thin diamond-like carbon (DLC) stripper foils ˜5 μg/cm2 in thickness were produced and evaluated as heavy-ion strippers for the Beijing HI-13 Tandem Accelerator. The DLC layers ˜4 μg/cm2 in thickness were produced by the filtered cathodic vacuum arc technology onto glass slides coated with betaine-saccharose as releasing agent, which were previously covered with evaporated carbon layers ˜1 μg/cm2 in thickness by the controlled ac arc-discharge method. Irradiation lifetimes of the DLC stripper foils were tested using the heavy-ion beams at the terminal of the Beijing HI-13 Tandem Accelerator, and compared with those of the standard carbon stripper foils made by the combined dc and ac arc-discharge method. The measurements indicate that the DLC stripper foils outlast the standard combined dc and ac arc-discharge carbon stripper foils by a factor of at least 13 and 4for the 197Au- (˜9 MeV, ˜1 μA) and 63Cu- (˜9 MeV, ˜1 μA) ion beams, respectively. The structure and properties of the DLC foils deposited onto silicon substrates by the filtered cathodic vacuum arc technology were also evaluated and analyzed by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The scanning electron microscopy images show that the DLC foils contain hardly droplets through the double 90° filters. The X-ray photoelectron spectrum indicates that sp3 bonds of the DLC foils exceed 70%. The integral intensity ratio of the D peak to the G peak (ID/IG) measured by the Raman spectroscopy is0.78.

  16. Managing aluminum phosphide poisonings.

    PubMed

    Gurjar, Mohan; Baronia, Arvind K; Azim, Afzal; Sharma, Kalpana

    2011-07-01

    Aluminum phosphide (AlP) is a cheap, effective and commonly used pesticide. However, unfortunately, it is now one of the most common causes of poisoning among agricultural pesticides. It liberates lethal phosphine gas when it comes in contact either with atmospheric moisture or with hydrochloric acid in the stomach. The mechanism of toxicity includes cellular hypoxia due to the effect on mitochondria, inhibition of cytochrome C oxidase and formation of highly reactive hydroxyl radicals. The signs and symptoms are nonspecific and instantaneous. The toxicity of AlP particularly affects the cardiac and vascular tissues, which manifest as profound and refractory hypotension, congestive heart failure and electrocardiographic abnormalities. The diagnosis of AlP usually depends on clinical suspicion or history, but can be made easily by the simple silver nitrate test on gastric content or on breath. Due to no known specific antidote, management remains primarily supportive care. Early arrival, resuscitation, diagnosis, decrease the exposure of poison (by gastric lavage with KMnO(4), coconut oil), intensive monitoring and supportive therapy may result in good outcome. Prompt and adequate cardiovascular support is important and core in the management to attain adequate tissue perfusion, oxygenation and physiologic metabolic milieu compatible with life until the tissue poison levels are reduced and spontaneous circulation is restored. In most of the studies, poor prognostic factors were presence of acidosis and shock. The overall outcome improved in the last decade due to better and advanced intensive care management.

  17. Managing aluminum phosphide poisonings

    PubMed Central

    Gurjar, Mohan; Baronia, Arvind K; Azim, Afzal; Sharma, Kalpana

    2011-01-01

    Aluminum phosphide (AlP) is a cheap, effective and commonly used pesticide. However, unfortunately, it is now one of the most common causes of poisoning among agricultural pesticides. It liberates lethal phosphine gas when it comes in contact either with atmospheric moisture or with hydrochloric acid in the stomach. The mechanism of toxicity includes cellular hypoxia due to the effect on mitochondria, inhibition of cytochrome C oxidase and formation of highly reactive hydroxyl radicals. The signs and symptoms are nonspecific and instantaneous. The toxicity of AlP particularly affects the cardiac and vascular tissues, which manifest as profound and refractory hypotension, congestive heart failure and electrocardiographic abnormalities. The diagnosis of AlP usually depends on clinical suspicion or history, but can be made easily by the simple silver nitrate test on gastric content or on breath. Due to no known specific antidote, management remains primarily supportive care. Early arrival, resuscitation, diagnosis, decrease the exposure of poison (by gastric lavage with KMnO4, coconut oil), intensive monitoring and supportive therapy may result in good outcome. Prompt and adequate cardiovascular support is important and core in the management to attain adequate tissue perfusion, oxygenation and physiologic metabolic milieu compatible with life until the tissue poison levels are reduced and spontaneous circulation is restored. In most of the studies, poor prognostic factors were presence of acidosis and shock. The overall outcome improved in the last decade due to better and advanced intensive care management. PMID:21887030

  18. Interpreting. PEPNet Tipsheet

    ERIC Educational Resources Information Center

    Darroch, Kathleen

    2010-01-01

    An interpreter's role is to facilitate communication and convey all auditory and signed information so that both hearing and deaf individuals may fully interact. The common types of services provided by interpreters are: (1) American Sign Language (ASL) Interpretation--a visual-gestural language with its own linguistic features; (2) Sign Language…

  19. Interpreting. NETAC Teacher Tipsheet.

    ERIC Educational Resources Information Center

    Darroch, Kathy; Marshall, Liza

    This tipsheet explains that an interpreter's role is to facilitate communication and convey all auditory and signed information so that individuals with and without hearing may fully interact. It outlines the common types of services provided by interpreters, and discusses principles guiding the professional behaviors of interpreters. When working…

  20. Real-time X-ray Diffraction Measurements of Shocked Polycrystalline Tin and Aluminum

    SciTech Connect

    Dane V. Morgan, Don Macy, Gerald Stevens

    2008-11-22

    A new, fast, single-pulse x-ray diffraction (XRD) diagnostic for determining phase transitions in shocked polycrystalline materials has been developed. The diagnostic consists of a 37-stage Marx bank high-voltage pulse generator coupled to a needle-and-washer electron beam diode via coaxial cable, producing line and bremsstrahlung x-ray emission in a 35-ns pulse. The characteristic Kα lines from the selected anodes of silver and molybdenum are used to produce the diffraction patterns, with thin foil filters employed to remove the characteristic Kβ line emission. The x-ray beam passes through a pinhole collimator and is incident on the sample with an approximately 3-mm by 6-mm spot and 1° full-width-half-maximum (FWHM) angular divergence in a Bragg-reflecting geometry. For the experiments described in this report, the angle between the incident beam and the sample surface was 8.5°. A Debye-Scherrer diffraction image was produced on a phosphor located 76 mm from the polycrystalline sample surface. The phosphor image was coupled to a charge-coupled device (CCD) camera through a coherent fiberoptic bundle. Dynamic single-pulse XRD experiments were conducted with thin foil samples of tin, shock loaded with a 1-mm vitreous carbon back window. Detasheet high explosive with a 2-mm-thick aluminum buffer was used to shock the sample. Analysis of the dynamic shock-loaded tin XRD images revealed a phase transformation of the tin beta phase into an amorphous or liquid state. Identical experiments with shock-loaded aluminum indicated compression of the face-centered-cubic (fcc) aluminum lattice with no phase transformation.