WorldWideScience

Sample records for aluminum foils interpreting

  1. Process for anodizing aluminum foil

    International Nuclear Information System (INIS)

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

    1984-01-01

    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 0 C. and then reanodizing the foil. The process is useful in anodizing foil to a voltage of up to 760 V

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

    Science.gov (United States)

    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. © 2015 American Academy of Forensic Sciences.

  3. Electrochemically replicated smooth aluminum foils for anodic alumina nanochannel arrays

    International Nuclear Information System (INIS)

    Biring, Sajal; Tsai, K-T; Sur, Ujjal Kumar; Wang, Y-L

    2008-01-01

    A fast electrochemical replication technique has been developed to fabricate large-scale ultra-smooth aluminum foils by exploiting readily available large-scale smooth silicon wafers as the masters. Since the adhesion of aluminum on silicon depends on the time of surface pretreatment in water, it is possible to either detach the replicated aluminum from the silicon master without damaging the replicated aluminum and master or integrate the aluminum film to the silicon substrate. Replicated ultra-smooth aluminum foils are used for the growth of both self-organized and lithographically guided long-range ordered arrays of anodic alumina nanochannels without any polishing pretreatment

  4. 75 FR 1596 - Grant of Authority for Subzone Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock...

    Science.gov (United States)

    2010-01-12

    ... Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock), Louisville, Kentucky Pursuant to its...-purpose subzone at the aluminum foil liner stock manufacturing and distribution facilities of Reynolds... manufacturing and distribution of aluminum foil liner stock and aluminum foil at the facilities of Reynolds...

  5. Research of plating aluminum and aluminum foil on internal surface of carbon fiber composite material centrifuge rotor drum

    International Nuclear Information System (INIS)

    Lu Xiuqi; Dong Jinping; Dai Xingjian

    2014-01-01

    In order to improve the corrosion resistance, thermal conductivity and sealability of the internal surface of carbon fiber/epoxy composite material centrifuge rotor drum, magnetron sputtering aluminum and pasting an aluminum foil on the inner wall of the drum are adopted to realize the aim. By means of XRD, SEM/EDS and OM, the surface topography of aluminum coated (thickness of 5 μm and 12 μm) and aluminum foil (12 μm) are observed and analyzed; the cohesion of between aluminum coated (or aluminum foil) and substrate material (CFRP) is measured by scratching experiment, direct drawing experiment, and shear test. Besides, the ultra-high-speed rotation experiment of CFRP ring is carried out to analyze stress and strain of coated aluminum (or aluminum foil) which is adhered on the ring. The results showed aluminum foil pasted on inner surface do better performance than magnetron sputtering aluminum on CFRP centrifuge rotor drum. (authors)

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

    Science.gov (United States)

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Element segregation on the surfaces of pure aluminum foils

    International Nuclear Information System (INIS)

    Zhang Xinming; Liu Jiancai; Tang Jianguo; Li Li; Chen Mingan; Liu Shengdan; Zhu Bing

    2010-01-01

    The surface segregation trend of trace elements in pure aluminum foils was investigated by density functional theory. The model of nine-layer Al(1 0 0) slab substituted partially by trace element atoms was proposed for calculating surface segregation energy. The calculating results show that (i) B, Mg, Si, Ga, Ge, Y, In, Sn, Sb, Pb and Bi exhibit negative segregation energy and possibly move to the surface, while Be, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zr exhibit positive segregation energies and migrated into the bulk; (ii) the segregation energy was found to be related with the covalent radius, the relaxed position at the surface of the substituting atom and the surface energy; (iii) the segregation behavior of trace element generates lots of defects and dislocation, which can increase the initial pitting nucleation sites in the surface of aluminum foils; (iv) the impurity atom concentration was tested with Pb-doped surfaces, the calculated negative segregation energies in all coverage increases rapidly with the Pb coverage. These conclusions are helpful for designing of the chemical composition and to advance the tunnel etching of aluminum foils.

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

    Science.gov (United States)

    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.

  9. Interpretation of aluminum-alloy weld radiography

    Science.gov (United States)

    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.

  10. Titanium conversion coatings on the aluminum foil AA 8021 used for lithium-ion battery package

    Science.gov (United States)

    Xia, Xu-Feng; Gu, Ying-Ying; Xu, Shi-Ai

    2017-10-01

    In this study, an environment-friendly titanium (Ti) conversion coating was successfully deposited on the aluminum foil AA 8021 in the solution containing hexafluorotitanic acid (H2TiF6), and its morphology, composition, growth process, hydrophilicity and corrosion resistance were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), X-ray photoelectric spectroscopy (XPS), contact-angle measurements (CAM) and salt spray exposure. The peeling strength between the Ti treated Al foil and the modified polypropylene (PP) film (PP grafted with maleic anhydride, PP-g-MAH) (Al/PP-g-MAH) was measured by T-peeling test. The results show that the Ti conversion coating is a multi-component coating composed primarily of metal oxides (TiO2 and Al2O3) and metal fluoride (AlF3). Ti treated Al foil shows better corrosion resistance than untreated and alkali-cleaned Al foils. The peeling strength of PP-g-MAH film with Ti treated Al foils is approximately 30 times higher than that with untreated Al foils. Thus, Ti treatment is a promising approach to improve the corrosion resistance and peeling strength of aluminum/polymer composite film (Al/P) used in the lithium-ion battery package.

  11. Thrust Generation with Low-Power Continuous-Wave Laser and Aluminum Foil Interaction

    International Nuclear Information System (INIS)

    Horisawa, Hideyuki; Sumida, Sota; Funaki, Ikkoh

    2010-01-01

    The micro-newton thrust generation was observed through low-power continuous-wave laser and aluminum foil interaction without any remarkable ablation of the target surface. To evaluate the thrust characteristics, a torsion-balance thrust stand capable for the measurement of the thrust level down to micro-Newton ranges was developed. In the case of an aluminum foil target with 12.5 micrometer thickness, the maximum thrust level was 15 micro-newtons when the laser power was 20 W, or about 0.75 N/MW. It was also found that the laser intensity, or laser power per unit area, irradiated on the target was significantly important on the control of the thrust even under the low-intensity level.

  12. Corrosion protection application of slippery liquid-infused porous surface based on aluminum foil

    Science.gov (United States)

    Tuo, Yanjing; Zhang, Haifeng; Chen, Weiping; Liu, Xiaowei

    2017-11-01

    Corrosion is a major problem for metal in marine systems. In this research, we fabricated a slippery liquid-infused porous surface (SLIPS) on the aluminum foil to protect the underneath metal. The as-fabricated samples were characterized with EDS, XRD, SEM, and contact angle meter. And the anti-corrosion property was evaluated by electrochemical measurements. The corrosion current density of SLIPS is ca.2 orders of magnitude lower than that of the untreated aluminum and superhydrophobic surface. And the impedance spectra of the SLIPS shows a large impedance semicircle with a diameter of several hundred kΩ.cm2. The SLIPS exhibits an outstanding corrosion protection capability, thus it has a broad application prospect in marine.

  13. The detection of reverse accumulation effect in the positron annihilation profile of stack of aluminum and silver foils

    Directory of Open Access Journals (Sweden)

    Dryzek Jerzy

    2015-12-01

    Full Text Available The implantation profile of positrons emitted from 22Na into a stack of aluminum and silver foils is the subject of the presented report. The characteristic dimple in the profile behind the Ag foil was detected. This effect arises from the differences in the linear absorption coefficient of aluminum and silver. The good agreement between the theoretical profile obtained within the multiscattering model and experimental one was achieved. The observed phenomenon can affect the positron annihilation characteristics measured for the inhomogeneous samples.

  14. Commercial Gold Nanoparticles on Untreated Aluminum Foil: Versatile, Sensitive, and Cost-Effective SERS Substrate

    Directory of Open Access Journals (Sweden)

    Kristina Gudun

    2017-01-01

    Full Text Available We introduce low-cost, tunable, hybrid SERS substrate of commercial gold nanoparticles on untreated aluminum foil (AuNPs@AlF. Two or three AuNP centrifugation/resuspension cycles are proven to be critical in the assay preparation. The limits of detection (LODs for 4-nitrobenzenethiol (NBT and crystal violet (CV on this substrate are about 0.12 nM and 0.19 nM, respectively, while maximum analytical SERS enhancement factors (AEFs are about 107. In comparative assays LODs for CV measured on AuNPs@Au film and AuNPs@glass are about 0.35 nM and 2 nM, respectively. The LOD for melamine detected on AuNPs@ Al foil is 27 ppb with 3 orders of magnitude for linear response range. Overall, AuNPs@AlF demonstrated competitive performance in comparison with AuNPs@ Au film substrate in SERS detection of CV, NBT, and melamine. To check the versatility of the AuNPs@AlF substrate we also detected KNO3 with LODs of 0.7 mM and SERS EF around 2 × 103, which is on the same order with SERS EF reported for this compound in the literature.

  15. Graphene-Armored Aluminum Foil with Enhanced Anticorrosion Performance as Current Collectors for Lithium-Ion Battery.

    Science.gov (United States)

    Wang, Mingzhan; Tang, Miao; Chen, Shulin; Ci, Haina; Wang, Kexin; Shi, Liurong; Lin, Li; Ren, Huaying; Shan, Jingyuan; Gao, Peng; Liu, Zhongfan; Peng, Hailin

    2017-12-01

    Aluminum (Al) foil, as the most accepted cathode current collector for lithium-ion batteries (LIBs), is susceptible to local anodic corrosions during long-term operations. Such corrosions could lead to the deterioration or even premature failure of the batteries and are generally believed to be a bottleneck for next-generation 5 V LIBs. Here, it is demonstrated that Al foil armored by conformal graphene coating exhibits significantly reinforced anodic corrosion resistance in both LiPF 6 and lithium bis(trifluoromethanesulphonyl) imide (LiTFSI) based electrolytes. Moreover, LiMn 2 O 4 cells using graphene-armored Al foil as current collectors (LMO/GA) demonstrate enhanced electrochemical performance in comparison with those using pristine Al foil (LMO/PA). The long-term discharge capacity retention of LMO/GA cell after ≈950 h straight operations at low rate (0.5 C) reaches up to 91%, remarkably superior to LMO/PA cell (75%). The self-discharge propensity of LMO/GA is clearly relieved and the rate/power performance is also improved with graphene mediations. This work not only contributes to the long-term stable operations of LIBs but also might catalyze the deployment of 5 V LIBs in the future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Local deposition of Copper on Aluminum based MWT Back Contact Foil using Cold Spray Technology

    Energy Technology Data Exchange (ETDEWEB)

    Goris, M.J.A.A.; Bennett, I.J.; Eerenstein, W. [ECN Solar Energy, Petten (Netherlands)

    2013-11-15

    MWT cell and module technology has been shown to result in modules with up to 5% higher power output than H-pattern modules and to be suitable for use with thin and fragile cells. In this study, the use of a low cost conductive back-sheet with aluminium as the current carrier in combination with locally applied copper (5 to 30 {mu}m) using the cold spray method is benchmarked against a standard PVF-PET-copper foil in 2 x 2 cell modules. Cell to module losses and reliability during climate chamber tests according to IEC61215 ed. 2, are comparable to module made with the standard foil. Optimizing the cold spray process can result in a cost reduction of more than a factor 10 of the current carrying component, when compared to a full copper conductive back-sheet foil.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Y.X., E-mail: yeyunxia@mail.ujs.edu.cn [School of Mechanical Engineering, Jiangsu University, Zhenjiang 21203 (China); Jiangsu Provincial Key Laboratory for Science and Technology of Photon Manufacturing, Jiangsu University, Zhenjiang 212013 (China); Xuan, T.; Lian, Z.C.; Feng, Y.Y.; Hua, X.J. [School of Mechanical Engineering, Jiangsu University, Zhenjiang 21203 (China)

    2015-06-01

    Highlights: • Crater-like microdefects formed on metal surface during laser shock process. • The air bubbles in the bonding material are responsible for forming microdefects. • Adiabatic compression of the air bubbles increases the temperature effectively. • Secondary shock wave induced by air bubbles is responsible for forming the defects. • Temperature increases due to shock heat and plastic deformation are limited. - Abstract: 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

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Adams, David P. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hirschfeld, Deidre A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hooper, Ryan J. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Manuel, Michelle V. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    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.

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Fabrication, performance, and figure metrology of epoxy-replicated aluminum foils for hard x-ray focusing multilayer-coated segmented conical optics

    DEFF Research Database (Denmark)

    Jimenez-Garate, M.A.; Craig, W.W.; Hailey, C.J.

    2000-01-01

    We fabricated x-ray mirrors for hard x-ray (greater than or equal to 10 keV) telescopes using multilayer coatings and an improved epoxy-replicated aluminum foil (ERAF) nonvacuum technology. The ERAF optics have similar to1 arcmin axial figure half-power diameter (HPD) and passed environmental...... telescope HPD, we designed a figure metrology system and a new mounting technique. We describe a cylindrical metrology system built for fast axial and roundness figure measurement of hard x-ray conical optics. These developments lower cost and improve the optics performance of the HEFT (high-energy focusing...

  2. Fabrication, performance, and figure metrology of epoxy-replicated aluminum foils for hard x-ray focusing multilayer-coated segmented conical optics

    DEFF Research Database (Denmark)

    Jimenez-Garate, M.A.; Craig, W.W.; Hailey, C.J.

    2000-01-01

    We fabricated x-ray mirrors for hard x-ray (greater than or equal to 10 keV) telescopes using multilayer coatings and an improved epoxy-replicated aluminum foil (ERAF) nonvacuum technology. The ERAF optics have similar to1 arcmin axial figure half-power diameter (HPD) and passed environmental...... testing. Reflectivity measurements at 8 keV on ERAFs with and without multilayer coatings show a 4.4 to 4.8 A root mean square (rms) microroughness for correlation lengths less than or equal to 15 mum. To reduce the dominant contribution of mirror assembly and large-scale distortion in the overall...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.; hide

    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.

  5. A Facile Green Synthetic Route for the Preparation of Highly Active γ-Al2O3from Aluminum Foil Waste.

    Science.gov (United States)

    Osman, Ahmed I; Abu-Dahrieh, Jehad K; McLaren, Mathew; Laffir, Fathima; Nockemann, Peter; Rooney, David

    2017-06-15

    A novel green preparation route to prepare nano-mesoporous γ-Al 2 O 3 from AlCl 3 .6H 2 O derived from aluminum foil waste and designated as ACFL550 is demonstrated, which showed higher surface area, larger pore volume, stronger acidity and higher surface area compared to γ-Al 2 O 3 that is produced from the commercial AlCl 3 precursor, AC550. The produced crystalline AlCl 3 .6H 2 O and Al(NO 3 ) 3 .9H 2 O in the first stage of the preparation method were characterized by single-crystal XRD, giving two crystal structures, a trigonal (R-3c) and monoclinic (P2 1 /c) structure, respectively. EDX analysis showed that ACFL550 had half the chlorine content (Cl%) relative to AC550, which makes ACFL550 a promising catalyst in acid-catalysed reactions. Pure and modified ACFL550 and AC550 were applied in acid-catalysed reactions, the dehydration of methanol to dimethyl ether and the total methane oxidation reactions, respectively. It was found that ACFL550 showed higher catalytic activity than AC550. This work opens doors for the preparation of highly active and well-structured nano-mesoporous alumina catalysts/supports from aluminum foil waste and demonstrates its application in acid-catalysed reactions.

  6. Foil Artists

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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.

  8. Joining sheet aluminum AA6061-T4 to cast magnesium AM60B by vaporizing foil actuator welding: Input energy, interface, and strength

    International Nuclear Information System (INIS)

    Liu, Bert; Vivek, Anupam; Daehn, Glenn S.

    2017-01-01

    Dissimilar joining of sheet aluminum AA6061-T4 to cast magnesium AM60B was achieved by vaporizing foil actuator welding (VFAW). Three input energy levels were used (6, 8, and 10 kJ), and as a trend, higher input energies resulted in progressively higher flyer velocities, more pronounced interfacial wavy features, larger weld zones, higher peel strengths, and higher peel energies. In all cases, weld cross section revealed a soundly bonded interface characterized by well-developed wavy features and lack of voids and continuous layers of intermetallic compounds (IMCs). At 10 kJ input energy, flyer speed of 820 m/s, peel strength of 22.4 N/mm, and peel energy of 5.2 J were obtained. In lap-shear, failure occurred in AA6061- T4 flyer at 97% of the base material’s peak tensile load. Peel samples failed along the weld interface, and the AM60B-side of the fracture surface showed thin, evenly-spaced lines of Al residuals which had been torn out of the base AA6061-T4 in a ductile fashion and transferred over to the AM60B side, indicating very strong AA6061-T4/AM60B bond in these areas. Furthermore, this work demonstrates VFAW’s capability in joining dissimilar lightweight metals such as Al/Mg, which is expected to be a great enabler in the ongoing push for vehicle weight reduction.

  9. An Experimental Study on Micro Clinching of Metal Foils with Cutting by Laser Shock Forming.

    Science.gov (United States)

    Wang, Xiao; Li, Cong; Ma, Youjuan; Shen, Zongbao; Sun, Xianqing; Sha, Chaofei; Gao, Shuai; Li, Liyin; Liu, Huixia

    2016-07-13

    This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils) and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils) were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination.

  10. An Experimental Study on Micro Clinching of Metal Foils with Cutting by Laser Shock Forming

    Directory of Open Access Journals (Sweden)

    Xiao Wang

    2016-07-01

    Full Text Available This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination.

  11. Foil Electron Multiplier

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Adhesive backing foil interactions affecting the elasticity, adhesion strength of laminates, and how to interpret these properties of branded transdermal patches.

    Science.gov (United States)

    Fauth, C; Wiedersberg, S; Neubert, R H H; Dittgen, M

    2002-11-01

    Standard tensile strength and peel adhesion tests were carried out to investigate interactions of pressure-sensitive adhesives (PSAs) with several backing foils used for transdermal patches. Seven branded transdermal patches (Alora, Cutanum, Estraderm MX 50, Estraderm TTS 50, Fem7 -50 micrograms, Menorest, Oesclim) were included in the investigation. Their skin adhesion measured in several clinical trials was compared with the results of the laboratory measurements according to PSTC-1 (Peel Adhesion for Single Coated Tapes 180 degrees Angle, Pressure Sensitive Tape Council, Illinois, 1996), such as Young's modulus at 3% elongation and peel adhesion to stainless steel. Data obtained for the PSA-coated backings (laminates) show increasing elasticity with increasing PSA thickness. Interactions of PSAs with backing foil became evident in significant changes in Young's modulus by low PSA thickness, as seen for the silicone adhesive. The Young's moduli of the laminates were found to be influenced not only by the elasticity of the backing foil but also by the chemical structure of the PSA. There was no correlation between the elasticity and peel adhesion of both the laminates and the branded patches. Likewise, for the branded patches the peel adhesion to stainless steel does not correlate with skin adhesion values obtained from clinical trials. The Young's modulus of the branded patches was between 4 N/mm2 (Oesclim) and 501 N/mm2 (Fem7). For the branded transdermal patches no correlation was found between Young's modulus and both the peel force on stainless steel and the skin adhesion reported in studies.

  14. Origin and paleoenvironmental interpretation of aluminum phosphate-sulfate minerals in a Neoproterozoic Baltic paleosol

    Science.gov (United States)

    Vircava, Ilze; Somelar, Peeter; Liivamägi, Sirle; Kirs, Juho; Kirsimäe, Kalle

    2015-04-01

    Aluminum phosphate-sulfate (APS) mineral solid-solutions occur as accessory phases in different sedimentary and hydrothermal deposits. Their composition is a sensitive environmental indicator recording changes in pH, temperature and chemical composition of the weathering, diagenetic or hydrothermal fluids. In this contribution we studied APS mineralization in a Neoproterozoic paleotropical paleosol developed on Paleo-Mesoproterozoic crystalline basement in the Baltic Basin. Small and disseminated APS minerals occur in high abundance (up to 4 wt.% of crystalline phases) in the weathering profile developed on gabbroic rocks rich in magmatic apatite. APS minerals belonging to a goyazite-florencite-svanbergite-woodhouseite solid-solution series occur in the uppermost part of the weathering profile and are replaced down-profile with secondary apatite. The change from APS minerals to secondary apatite precipitates reflects a paleo-pH gradient in the weathering profile from acidic (pH meters in the APS precipitation zone, to neutral or near neutral at 4-5 m-depth from the paleoweathered surface where secondary apatite occurs. Typically uniform < 5 μm-size APS crystallites suggest rapid precipitation in a highly supersaturated solution, but these crystals show a fine zonal structure whose nature and formation mechanism remain unclear.

  15. 78 FR 28577 - Notification of Proposed Production Activity, LLFlex, LLC, Subzone 29J (Foil Backed Paperboard...

    Science.gov (United States)

    2013-05-15

    ... Foreign-Trade Zones Board Notification of Proposed Production Activity, LLFlex, LLC, Subzone 29J (Foil...) was received on May 6, 2013. The subzone currently has authority to produce aluminum foil liner stock. The current request would add foil backed paperboard to the list of approved finished products...

  16. Bonded Invar Clip Removal Using Foil Heaters

    Science.gov (United States)

    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. Oscillating foil propulsion

    OpenAIRE

    Hauge, Jacob

    2013-01-01

    Unsteady foil theory is discussed and applied on several cases of an oscillating foil. The oscillating foil is meant as a propulsion system for a platform supply vessel.Four case studies of foil oscillation have been performed. A thrust coefficient of 0.1 was achieved at an efficiency of 0.75. A thrust coefficient of minimum 0.184 is necessary to overcome the calm water resistance of the foil.Issues connected to coupled vessel-foil models are discussed.

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

    Science.gov (United States)

    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.

  19. Method of forming a thin unbacked metal foil

    Science.gov (United States)

    Duchane, David V.; Barthell, Barry L.

    1984-01-01

    In a method of forming a thin (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.

  20. Interpretations

    Science.gov (United States)

    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!

  1. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Foil Face Seal Testing

    Science.gov (United States)

    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.

  3. X-Ray Measurements Of Total Reflectivity And Scattering From Au-Coated Foils

    DEFF Research Database (Denmark)

    Hornstrup, Allan; Christensen, Finn Erland; Schnopper, H. W.

    1989-01-01

    We present X-ray measurements of total reflectivity and scattering from gold coated foils. The foils are two sorts of 0.3 mm thick dip-lacquered aluminum, 0.125 mm thick plastic (Upilex) and 0.5 mm thick dip-lacquered nickel. The analysis of the data show a high reflectivity for all but the plastic...... foil, and only small microroughness (-10A at lengthscales below -0.1 micron), evidenced by low resolution scat-tering measurements....

  4. Compositional characterization of thin foil by instrumental heavy ion activation analysis

    International Nuclear Information System (INIS)

    Chowdhury, D.P.; Pal, Sujit; Guin, R.; Saha, S.K.; Venkataramani, B.

    2007-01-01

    The elemental composition of a thin (2 mm) Havar foil was determined by instrumental heavy ion activation analysis (HIAA). The recoiled products, coming out of thin target, were separated and absorbed in graded thickness of aluminum catcher foils as per their recoil ranges. Activation technique was followed for the quantitative estimation using elemental standards by comparator technique. (author)

  5. Monolithic exploding foil initiator

    Science.gov (United States)

    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.

  6. Effect of phototherapy with alumunium foil reflectors on neonatal hyperbilirubinemia

    Directory of Open Access Journals (Sweden)

    Tony Ijong Dachlan

    2015-03-01

    Full Text Available Background Neonatal hyperbilirubinemia (NH is one of the most common problems in neonates, but it can be treated with blue light phototherapy. Developing countries with limited medical equipment and funds have difficulty providing effective phototherapy to treat NH, leading to increased risk of bilirubin encephalopathy. Phototherapy with white reflecting curtains can decrease the duration of phototherapy needed to reduce bilirubin levels. Objective To compare the duration of phototherapy needed in neonates with NH who underwent phototherapy with and without aluminum foil reflectors. Methods This open clinical trial was conducted from July to August 2013 at Dr. Hasan Sadikin Hospital, Bandung, Indonesia. The inclusion criteria were term neonates with uncomplicated NH presenting in their first week of life. Subjects were randomized into two groups, those who received phototherapy with or without aluminum foil reflectors. Serum bilirubin is taken at 12th, 24th, 48th hours, then every 24 hours if needed until phototherapy can be stopped according to American Academy of Pediatrics guidelines. The outcome measured was the duration of phototherapy using survival analysis. The difference between the two groups was tested by Gehan method. Results Seventy newborns who fulfilled the inclusion criteria and had similar characteristics were randomized into two groups. The duration of phototherapy needed was significantly less in the group with aluminum foil reflectors than in the group without reflectors [72 vs. 96 hours, respectively, (P<0.01]. Conclusion The required duration of phototherapy with aluminum foil reflectors is significantly less than that of phototherapy without reflectors, in neonates with NH.

  7. Defect reduction in seeded aluminum nitride crystal growth

    Energy Technology Data Exchange (ETDEWEB)

    Bondokov, Robert T.; Morgan, Kenneth E.; Schowalter, Leo J.; Stack, Glen A.

    2017-04-18

    Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density.ltoreq.100 cm.sup.-2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

  8. Defect reduction in seeded aluminum nitride crystal growth

    Energy Technology Data Exchange (ETDEWEB)

    Bondokov, Robert T.; Morgan, Kenneth E.; Schowalter, Leo J.; Slack, Glen A.

    2017-06-06

    Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density .ltoreq.100 cm.sup.-2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

  9. Defect reduction in seeded aluminum nitride crystal growth

    Science.gov (United States)

    Bondokov, Robert T.; Schowalter, Leo J.; Morgan, Kenneth; Slack, Glen A; Rao, Shailaja P.; Gibb, Shawn Robert

    2017-09-26

    Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density.ltoreq.100 cm.sup.-2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

  10. Development and preparation of thin, supported targets and stripper foils

    International Nuclear Information System (INIS)

    Aaron, W.S.; Petek, M.; Zevenbergen, L.A.; Gibson, J.R.

    1989-01-01

    Usually, it is desirable to prepare thin films that are self-supporting so that any extraneous support materials will not interfere with experimental measurements. However, films with very low areal densities, films other than metals or films covering large areas may require the use of a backing or support. Two classes of supported thin films are being developed by the Isotope Research Materials Laboratory (IRML). Electrodeposition of oxide thin films is a fairly common target preparation technique that is usually performed on backings such as thin metal foils or low atomic number materials like Be and to a lesser extent, C foils. Techniques have been developed by IRML that result in electrodeposition of oxide films up to 500 μg/cm 2 on carbon foils or aluminized mylar. Electrodeposition is a very attractive target fabrication method since it is very efficient in the usage of rare and/or valuable isotopes. The ability to prepare these films on carbon or mylar foils provides a target that has, in most applications, far less interference resulting from the backing. Thin films of carbon, aluminum, boron and titanium are being used as stripper foils in the generation of neutral (H - →H 0 ) particle beams with energies of 50 MeV or greater. Neutralizer foils as large as 25 cm x 25 cm have been prepared from Al and C in thicknesses ranging from 5 to 12 μg/cm 2 that are mounted on thin nickel grids with a transmittance of approximately 90%. Significantly larger foils are currently under development. (orig.)

  11. X-ray measurements of total reflectivity and scattering from Au-coated foils

    DEFF Research Database (Denmark)

    Hornstrup, Allan; Christensen, Finn Erland; Jespersen, Ellen

    1990-01-01

    We present x-ray measurements of total reflectivity and scattering from gold-coated foils. The foils are two sorts of 0.3 mm thick dip-lacquered aluminum, 0.125 mm thick plastic (Upilex) and 0.5 mm thick dip-lacquered nickel. The analysis of the data shows a high reflectivity for all...... but the plastic foil, and only small microroughness (∼15 Å at length scales below ∼0.1 μm), evidenced by low resolution scattering measurements....

  12. FOIL ELEMENT FOR NUCLEAR REACTOR

    Science.gov (United States)

    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)

  13. Consequences of FOIL for Undergraduates

    Science.gov (United States)

    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…

  14. Ultrasonic-Assisted Incremental Microforming of Thin Shell Pyramids of Metallic Foil

    Directory of Open Access Journals (Sweden)

    Toshiyuki Obikawa

    2017-05-01

    Full Text Available Single point incremental forming is used for rapid prototyping of sheet metal parts. This forming technology was applied to the fabrication of thin shell micropyramids of aluminum, stainless steel, and titanium foils. A single point tool used had a tip radius of 0.1 mm or 0.01 mm. An ultrasonic spindle with axial vibration was implemented for improving the shape accuracy of micropyramids formed on 5–12 micrometers-thick aluminum, stainless steel, and titanium foils. The formability was also investigated by comparing the forming limits of micropyramids of aluminum foil formed with and without ultrasonic vibration. The shapes of pyramids incrementally formed were truncated pyramids, twisted pyramids, stepwise pyramids, and star pyramids about 1 mm in size. A much smaller truncated pyramid was formed only for titanium foil for qualitative investigation of the size reduction on forming accuracy. It was found that the ultrasonic vibration improved the shape accuracy of the formed pyramids. In addition, laser heating increased the forming limit of aluminum foil and it is more effective when both the ultrasonic vibration and laser heating are applied.

  15. Large-area beryllium metal foils

    Science.gov (United States)

    Stoner, J. O., Jr.

    1997-02-01

    To manufacture beryllium filters having diameters up to 82 mm and thicknesses in the range 0.1-1 μm, it was necessary to construct apparatus in which the metal could safely be evaporated, and then to find an acceptable substrate and evaporation procedure. The metal was evaporated resistively from a tantalum dimple boat mounted in a baffled enclosure that could be placed in a conventional vacuum bell jar, obviating the need for a dedicated complete vacuum system. Substrates were 102 mm × 127 mm × 0.05 mm cleaved mica sheets, coated with 0.1 μm of NaCl, then with approximately 50 μg/cm 2 of cellulose nitrate. These were mounted on poly(methyl methacrylate) sheets 3 mm thick that were in turn clamped to a massive aluminum block for thermal stability. Details of the processes for evaporation, float off, and mounting are given, and the resulting foils described.

  16. The effects of deoxidation practice on the quality of thin foil low-carbon steel

    Directory of Open Access Journals (Sweden)

    Pereira Batista R.

    2017-01-01

    Full Text Available In converter steelmaking of AISI 1006 steel for thin foil products, two tapping practices are used with respect to deoxidation: silicon and manganese additions during tapping and aluminum deoxidation after complete tapping (“semikilled practice” and aluminum deoxidation during tapping, “fully killed practice”. There is a perception that the semikilled practice may be more economical and result in the same quality as the fully killed practice. In this work, the effects of the tapping practice on steel quality and cost variables were evaluated for thin foils of AISI 1006 steel. Oxygen and aluminum content, aluminum and ferro-alloy yield, the type of alumina inclusions formed, and the quality of the steel during thin foil rolling were evaluated and compared. It is shown that the fully killed practice leads to less reoxidation from slag, lower soluble oxygen, and lower total oxygen at the caster as well as better morphology of the remaining alumina inclusions than the semi-killed practice. Thus, the higher quality of the steel produced via the fully killed tapping deoxidation practice when compared with semi-killed tapping is demonstrated. It is also shown that a complete cost evaluation favors this practice in the case of products rolled for tin foil production.

  17. Scanning tunneling microscopy studies of thin foil x-ray mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Besenbacher, Flemming; Garnaes, Jorgen

    1990-01-01

    In this paper scanning tunneling microscopy (STM) measurements of x-ray mirrors are presented. The x-ray mirrors are 0.3 mm thick dip-lacquered aluminum foils coated with gold by evaporation, as well as state-of-the-art polished surfaces coated with gold, platinum, or iridium. The measurements...

  18. Foil-to-foil system integration through capillary self-alignment directed by laser patterning

    OpenAIRE

    Arutinov, G Gari; Mastrangeli, M; Smits, ECP Edsger; Heck, van, G; Toonder, den, JMJ Jaap; Dietzel, AH Andreas

    2015-01-01

    This paper introduces a new integration technology for cost-effective high-precision mechanical and electrical integration of mesoscopic functional foil components onto foil substrates. The foil-to-foil assembly process is based on topological surface structuring via laser patterning that enables accurate capillarity-driven self-alignment of foil dies. The concurrent establishment of high-yield electrical interconnections is obtained through conductive adhesives. The foil surface energy contr...

  19. Post-foil interaction in foil-induced molecular dissociation

    International Nuclear Information System (INIS)

    Faibis, A.; Kanter, E.P.; Koenig, W.; Plesser, I.; Vager, Z.

    1985-01-01

    The authors have investigated the foil-induced dissociation of 175- 250- keV/amu CH + , NH + , and OH + , FH + and NeH + ions by coincident detection of the fragment atoms. The dissociation energies corresponding to in-foil and post-foil interactions were deduced from the measured relative flight times of the fragment pairs to a set of detectors downstream from the target. The authors considered final states consisting of a) a proton and a heavy-ion and, b) a hydrogen atom and a heavy-ion. Surprisingly, in both cases the energy released in the post-target interaction shows a similar linear increase with the charge state of the heavy partner

  20. Application of physical and numerical simulations for interpretation of peripheral coarse grain structure during hot extrusion of AA7020 aluminum alloy

    NARCIS (Netherlands)

    Eivani, A.R.; Zhou, J.

    2017-01-01

    In this research, hot compression test is used to simulate the metallurgical phenomena occurring in the peripheral part of AA7020 aluminum alloy extrudates during hot extrusion and leading to the formation of the peripheral coarse grain (PCG) structure. The temperature profiles at a tracking

  1. Aluminum: Reflective Aluminum Chips

    Energy Technology Data Exchange (ETDEWEB)

    Recca, L.

    1999-01-29

    This fact sheet reveals how the use of reflective aluminum chips on rooftops cuts down significantly on heat absorption, thus decreasing the need for air conditioning. The benefits, including energy savings that could reach the equivalent of 1.3 million barrels of oil annually for approximately 100,000 warehouses, are substantial.

  2. Numerical and experimental investigation of bump foil mechanical behaviour

    DEFF Research Database (Denmark)

    Larsen, Jon Steffen; Cerda Varela, Alejandro Javier; Santos, Ilmar

    2014-01-01

    Corrugated foils are utilized in air foil bearings to introduce compliance and damping thus accurate mathematical predictions are important. A corrugated foil behaviour is investigated experimentally as well as theoretically. The experimental investigation is performed by compressing the foil...

  3. kFOIL: Learning simple relational kernels

    OpenAIRE

    Landwehr, Niels; Passerini, Andrea; De Raedt, Luc; Frasconi, Paolo

    2006-01-01

    A novel and simple combination of inductive logic programming with kernel methods is presented. The kFOIL algorithm integrates the well-known inductive logic programming system FOIL with kernel methods. The feature space is constructed by leveraging FOIL search for a set of relevant clauses. The search is driven by the performance obtained by a support vector machine based on the resulting kernel. In this way, kFOIL implements a dynamic propositionalization approach. Both classification an...

  4. Foil-to-Foil system integration through capillary self-alignment directed by laser patterning

    NARCIS (Netherlands)

    Arutinov, G.; Mastrangeli, M.; Smits, E.C.P.; Heck, G. van; Toonder, J.M.J. den; Dietzel, A.H.

    2014-01-01

    This paper introduces a new integration technology for cost-effective high-precision mechanical and electrical integration of mesoscopic functional foil components onto foil substrates. The foil-to-foil assembly process is based on topological surface structuring via laser patterning that enables

  5. Passive Thermal Management of Foil Bearings

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.)

  7. Aluminum Hydroxide

    Science.gov (United States)

    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. Development of a new foil positioning mechanism

    International Nuclear Information System (INIS)

    Ansari, Q.N.; Bhagwat, P.V.; Gupta, A.K.; Choudhury, R.K.

    2009-01-01

    In a tandem accelerator, negative ions are accelerated to high voltage terminal where beam pass through a foil stripper/gas stripper or combination of both, ultimately positive ions accelerated. The optimum thickness of stripper foil is in the range of 3-5 μg/cm 2 for 14 MeV ion beam. A new foil changing system for Pelletron Accelerator has been developed based on micro-stepping stepper motor arrangement. Present Geneva based mechanism is driven by the AC motor using belt and pulley, which rotates by 90° for each revolution of motor shaft and brings the foil in position with beam axis. The belt carries 200 foils and due to prolonged usage and subsequent slackness of the belt, the foil position is not reproducible. Also, it is found that sometimes foil position is proper either in increase or in decrease mode. There is no provision to adjust foil position with respect to beam axis in the current mechanism. To overcome this problem a new stepper motor based system is under development which uses smooth rotation and fine positioning. Micro-controller chip used is programmed to control the rotation and select the foils in increase/decrease mode. In addition, a fine control is also provided to adjust the angular position of foil to avail optimum transmission. This paper presents the salient features of the foil positioning mechanism. (author)

  9. Zika Vaccine Development: Flavivirus Foils

    Science.gov (United States)

    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

  10. Induction of subterahertz surface waves on a metal wire by intense laser interaction with a foil

    Science.gov (United States)

    Teramoto, Kensuke; Inoue, Shunsuke; Tokita, Shigeki; Yasuhara, Ryo; Nakamiya, Yoshihide; Nagashima, Takeshi; Mori, Kazuaki; Hashida, Masaki; Sakabe, Shuji

    2018-02-01

    We have demonstrated that a pulsed electromagnetic wave (Sommerfeld wave) of subterahertz frequency and 11-MV/m field strength can be induced on a metal wire by the interaction of an intense femtosecond laser pule with an adjacent metal foil at a laser intensity of 8.5 × 1018W /c m2 . The polarity of the electric field of this surface wave is opposite to that obtained by the direct interaction of the laser with the wire. Numerical simulations suggest that an electromagnetic wave associated with electron emission from the foil induces the surface wave. A tungsten wire is placed normal to an aluminum foil with a gap so that the wire is not irradiated and damaged by the laser pulse, thus making it possible to generate surface waves on the wire repeatedly.

  11. Experimental investigation on the bi-directional growing mechanism of the foils laminate approach in AAO fabrication

    Directory of Open Access Journals (Sweden)

    Chien Ming-Chun

    2006-01-01

    Full Text Available AbstractThe foils laminate approach can be implemented to grow bi-directional porous pattern from both the top and bottom surfaces of an aluminum foil. It was intuitively inferred that leakage of etchant from the clamped area can be a feasible cause to have the upward pores grow in the notches of the unpolished surface. This leakage hypothesis has been disproved by the leakage blocking and triple layers laminate experiments. It is further inferred that the non-uniformity of the thickness or material properties of the aluminum foil causes non-uniformed anodization rate along the sample surface. The fast oxidized areas create a pathway for leakage such that a shorter porous array from the back side is observed. Experiments with the process time being reduced by two hours validate this inference

  12. Technical Development Path for Gas Foil Bearings

    Science.gov (United States)

    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.

  13. Performance Analysis of Gas Foil Bearing with Different Foil Pivot Configuration

    OpenAIRE

    Milind Babasaheb Patil; Karuna Kalita; Sashindra K. Kakoty

    2013-01-01

    A numerical model is developed in order to find out the performance characteristics of gas foil bearings. The static performance analysis of gas foil bearings has been carried out using an elastic foundation model of the foil. The steady state results have been compared with the experimental and theoretical results available in the literature. The characteristics of the bearing have been investigated with change in foil pivot position. It has been shown that the load carrying capacity is diff...

  14. Radiation lifetimes and failure mechanisms of carbon stripper foils

    International Nuclear Information System (INIS)

    Auble, R.L.

    1981-01-01

    Measurements of lifetimes of thin carbon foils under heavy-ion irradiation are compiled and recent advances in stripper foil technology are reviewed. The impact of recent foil lifetime improvements, many by more than an order of magnitude, on heavy-ion electrostatic accelerators is discussed. Foil inhomogeneities, particularly those caused by sputtering are suggested to be a prime factor in usable foil lifetimes

  15. Visualization and Measurement of the Deflagration of JA2 Bonded to Various Metal Foils

    Science.gov (United States)

    2016-01-01

    aluminum or copper (Cu) foils with thicknesses of 1–3 mils were bonded to one side of JA2 sheet stock . 2. Approach 2.1 Test-Article Fabrication...ARL-MR-0914 ● JAN 2016 US Army Research Laboratory Visualization and Measurement of the Deflagration of JA2 Bonded to Various...this report when it is no longer needed. Do not return it to the originator. ARL-MR-0914 ● JAN 2016 US Army Research Laboratory

  16. An Investigation into Ground Effect for an Underwater Biologically Inspired Flapping Foil

    Science.gov (United States)

    2014-01-01

    example, such vortices when trapped beneath a moving automobile and the ground can increase the vehicle’s negative lift (downforce). This aerodynamic...a foil, an aluminum carriage attachment assembly, an instrument chassis , a power supply, a laser distance measurement (LDM) device on the tow tank...block is moved with the dual canister apparatus each time it is removed from the carriage, and connects to the chassis (NI PXIe-1082) via a National

  17. Recovery and distribution of incinerated aluminum packaging waste.

    Science.gov (United States)

    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. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  18. Ultrathin foils used for low-energy neutral atom imaging of the terrestrial magnetosphere

    Science.gov (United States)

    Funsten, Herbert O.; McComas, David J.; Barraclough, Bruce L.

    1993-12-01

    Magnetospheric imaging by remote detection of low-energy neutral atoms (LENAs) that are created by charge exchange between magnetospheric plasma ions and neutral geocoronal atoms has been proposed as a method to provide global information of magnetospheric dynamics. For LENA detection, carbon foils can be implemented to (1) ionize the LENAs and electrostatically remove them from the large background of solar UV scattered by the geocorona and (2) generate secondary electrons to provide coincidence and/or LENA trajectory information. Quantification of LENA-foil interactions are crucial in defining LENA imager performance. We present equilibrium charge state and angular scatter distributions for 1 to 30-keV atomic hydrogen, helium, and oxygen transiting nominal 0.5 (mu) g cm-2 carbon foils. Results obtained after coating the exit surface of foils with either aluminum or gold suggest that the intended alteration of the exit surface chemistry has no effect on the charge state distributions due to foil contamination from exposure to air.

  19. A metal-lustrous porphyrin foil.

    Science.gov (United States)

    Morisue, Mitsuhiko; Hoshino, Yuki; Shimizu, Masaki; Tomita, Shogo; Sasaki, Sono; Sakurai, Shinichi; Hikima, Takaaki; Kawamura, Ayaka; Kohri, Michinari; Matsui, Jun; Yamao, Takeshi

    2017-09-26

    A metal-lustrous self-standing film, named "porphyrin foil", was formed from a glass-forming polymeric porphyrin. The amorphous glass nature of the porphyrin foil played a key role in spontaneously producing a smooth surface. Its sharp contrast in intense absorption and specular reflection of light at each wavelength provided a brilliant metallic lustre.

  20. Dress Images on Gold-foil Figures

    DEFF Research Database (Denmark)

    Mannering, Ulla; Andersson Strand, Eva Birgitta

    2009-01-01

    From the Late Iron Age settlement Sorte Muld on Bornholm both gold foil figures with depictions of costumes and textile tools can tell about textile production.......From the Late Iron Age settlement Sorte Muld on Bornholm both gold foil figures with depictions of costumes and textile tools can tell about textile production....

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Gas permeability through thin-foil x-ray filters

    Science.gov (United States)

    Tveekrem, June L.; Keski-Kuha, Ritva A.; Webb, Andrew T.

    1997-10-01

    We have measured the permeation rates of helium and water through thin-foil UV-blocking filters used in the ASTRO-E/x- ray spectrometer (XRS) instrument. In the XRS program, there is a concern that outgassed contaminants such as water could permeate through the outermost filter which will be at room temperature and freeze on the inner filters which will be at cryogenic temperatures. The filters tested consisted of approximately 1000 angstroms Al on approximately 1000 angstroms of either Lexan or polyimide. Measurements were made using a vacuum apparatus consisting essentially of two small chambers separated by the filter under test. A helium leak detector was used to measure helium permeation rates, and a residual gas analyzer (RGA) was used to detect water. Results discussed include permeation rate as a function of pressure difference across a filter, the ratio of helium permeation rate over water permeation rate, and the effect of the aluminum layer thickness on permeation.

  3. Circuit design on plastic foils

    CERN Document Server

    Raiteri, Daniele; Roermund, Arthur H M

    2015-01-01

    This book illustrates a variety of circuit designs on plastic foils and provides all the information needed to undertake successful designs in large-area electronics.  The authors demonstrate architectural, circuit, layout, and device solutions and explain the reasons and the creative process behind each. Readers will learn how to keep under control large-area technologies and achieve robust, reliable circuit designs that can face the challenges imposed by low-cost low-temperature high-throughput manufacturing.   • Discusses implications of problems associated with large-area electronics and compares them to standard silicon; • Provides the basis for understanding physics and modeling of disordered material; • Includes guidelines to quickly setup the basic CAD tools enabling efficient and reliable designs; • Illustrates practical solutions to cope with hard/soft faults, variability, mismatch, aging and bias stress at architecture, circuit, layout, and device levels.

  4. Aluminum Analysis.

    Science.gov (United States)

    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)

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

    Science.gov (United States)

    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.

  6. Hyaluronan-lecithin foils and their properties

    Energy Technology Data Exchange (ETDEWEB)

    BiaIopiotrowicz, Tomasz [Department of Interfacial Phenomena, Faculty of Chemistry, Maria Curie-SkIodowska University, Maria Curie-SkIodowska Square 3, 20-031 Lublin (Poland); Janczuk, BronisIaw [Department of Interfacial Phenomena, Faculty of Chemistry, Maria Curie-SkIodowska University, Maria Curie-SkIodowska Square 3, 20-031 Lublin (Poland); Fiedorowicz, Maciej [Department of Chemistry, Agricultural University of Krakow, Mickiewicz Ave., 21, 31 120 Cracow (Poland); Khachatryan, Gohar [Department of Chemistry, Agricultural University of Krakow, Mickiewicz Ave., 21, 31 120 Cracow (Poland); Tomasik, Piotr [Department of Chemistry, Agricultural University of Krakow, Mickiewicz Ave., 21, 31 120 Cracow (Poland)]. E-mail: rrtomasi@cyf-kr.edu.pl; Bakos, Dusan [Faculty of Chemical and Food Technology, Slovak Technical University, Radlinskeho 9, 812 37 Bratislava (Slovakia)

    2006-01-10

    Thin, elastic foils of good resistance to the air exposure, patented as wound healing aids, were prepared by evaporation of a blend of lecithin (L) and sodium hyaluronan (H) taken under varying proportions. The contact angle for water, glycerol, formamide, ethylene glycol and diiodomethane, was determined for these foils. The contact angle was correlated against the H:L foil composition. For all liquids but formamide the highest contact angle was noted for the H:L = 2:1 (g g{sup -1}) ratio. The contact angles provided estimation of the work of adhesion. At the same L:H ratio the work of adhesion was the lowest. It was suggested that lecithin cross-linked hyaluronan. Since the work of adhesion of the studied liquids was similar to that of diiodomethane, it could be concluded that almost all functional groups on the foil surface were completely blocked. Perhaps, at H:L = 2:1 (g g{sup -1}) a stoichiometric complex of hyaluronic acid with lecithin was formed, and polar functional groups from both reagents were involved. Foils seem to be electrostatic complexes of H with L. Foils with the H:L equal to 2:1 exhibited specific properties confirmed by the IR reflectance spectra of the foils. The thermogravimetry (TG/DTG) also revealed unique thermal behaviour confirming other specific properties of the foil of this composition. For the same ratio a thorough inspection of the scanning electron micrographs (SEM) revealed few irregularly distributed perforations of 1-2 {mu}m in diameter seen as black points, which can be recognized as pores. Properties of the foils determined in the contact angle measurements are nicely backed by the results from thermogravimetric and scanning electron microscopic studies.

  7. Failure Behavior of Aluminum-Titanium Hybrid Seams within a Novel Aluminum-CFRP Joining Concept

    Science.gov (United States)

    Woizeschke, P.; Schumacher, J.

    Modern light weight designs include various materials to create specific local properties. Hence, joining of dissimilar materials is an important task, especially the combination of carbon fiber reinforced plastics and aluminum alloys is a favored choice. In this paper, investigations on a novel joining concept for these materials are shown carried out within the DFG research group "Schwarz-Silber" at the University of Bremen. A titanium transition structure consisting of a foil laminate is applied. On the aluminum side joining is realized by a simultaneous double-sided laser process. In the results the failure behavior of this joint is characterized.

  8. Analysis of Mechanical Properties for GEM Foil

    CERN Document Server

    Chin, Yuk Ming

    2016-01-01

    In view of new assembly technique of the GEM detector; in which three foils stack is stretched to get the uniform gaps among the foils. We studied the mechanical properties of the foil material. We conditioned the samples in different environments to make them extra dry and wet. As holes are the major source of the charge amplification their deformation can effect the detector performance. Therefore in our studies we also studied at which level of the stress the holes deformation is seen. These tensile and holes deformation studies can help to optimize the stress during detector assembly.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ozaltun, Hakan [Idaho National Laboratory; Medvedev, Pavel G [Idaho National Laboratory

    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.

  10. Radioactivity analysis in niobium activation foils

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, G.E.

    1995-06-01

    The motivation for this study was to measure and analyze the activity of six (6) niobium (Nb) foils (the x-rays from an internal transition in Nb-93m) and apply this information with previously obtained activation foil data. The niobium data was used to determine the epithermal to MeV range for the neutron spectrum and fluence. The foil activation data was re-evaluated in a spectrum analysis code (STAY`SL) to provide new estimates of the exposure at the Los Alamos Spallation Radiation Effect Facility (LASREF). The activity of the niobium foils was measured and analyzed at the University of Missouri-Columbia (UMC) under the direction of Professor William Miller. The spectrum analysis was performed at the University of Missouri-Rolla (UMR) by Professor Gary Mueller.

  11. Transient and steady state behaviour of elasto–aerodynamic air foil bearings, considering bump foil compliance and top foil inertia and flexibility: A numerical investigation

    DEFF Research Database (Denmark)

    Nielsen, Bo Bjerregaard; Santos, Ilmar F.

    2017-01-01

    This work gives a theoretical contribution to the problem of modelling air foil bearings considering large sagging effects in the calculation of the non-linear transient and steady state response of a rigid rotor. This paper consists of two parts: the development of a miltiphysics model of the air...... foils and one air foil bearing with a fully supported top foil. The steady state responses of a journal supported by these air foil bearings are investigated for varied rotational speeds and journal unbalances as well as the top foil sagging in the unsupported area. The study reveals that sub...

  12. An investigative approach to explore optimum assembly process design for annular targets carrying LEU foil

    Science.gov (United States)

    Hoyer, Annemarie

    Technetium-99m is the most widely used nuclear isotope in the medical field, with nearly 80 to 85% of all diagnostic imaging procedures. The daughter isotope of molybdenum-99 is currently produced using weapons-grade uranium. A suggested design for aluminum targets carrying low-enriched uranium (LEU) foil is presented for the fulfillment of eliminating highly enriched uranium (HEU) for medical isotope production. The assembly process that this research focuses on is the conventional draw-plug process which is currently used and lastly the sealing process. The research is unique in that it is a systematic approach to explore the optimal target assembly process to produce those targets with the required quality and integrity. Conducting 9 parametric experiments, aluminum tubes with a nickel foil fission-barrier and a surrogate stainless steel foil are assembled, welded and then examined to find defects, to determine residual stresses, and to find the best cost-effective target dimensions. The experimental design consists of 9 assembly combinations that were found through orthogonal arrays in order to explore the significance of each factor. Using probabilistic modeling, the parametric study is investigated using the Taguchi method of robust analysis. Depending on the situation, optimal conditions may be a nominal, a minimized or occasionally a maximized condition. The results will provide the best target design and will give optimal quality with little or no assembly defects.

  13. Numerical simulation of non-standard tensile tests of thin metal foils

    Science.gov (United States)

    Bolzon, Gabriella; Shahmardani, Mahdieh

    2018-01-01

    The evolution of the fracture processes occurring in thin metal foils can be evidenced by tensile tests performed on samples of non-standard dimensions. The load versus displacement record of these experiments does not return directly the local stress-strain relationship and the fracture characteristics of the investigated material. In fact, the overall response of thin foils is sensitive to local imperfections, size and geometric effects. Simulation models of the performed tests can support the interpretation of the experimental results, provided that the most significant physical phenomena are captured. The present contribution focuses on the role of modelling details on the numerical output that can be obtained in this context.

  14. Beam-foil spectroscopy of chlorine and sulfur ions

    International Nuclear Information System (INIS)

    Frot, D.; Barchewitz, R.; Cukier, M.; Bruneau, J.

    1987-01-01

    We report on the measurement of spectra of highly stripped chlorine and sulfur ions in the energy ranges of, respectively, 2900 - 3500 eV and 2300 - 2600 eV. The spectra have been obtained after excitation of ions travelling through a thin carbon foil. X-rays emitted by the emerging beam are analysed with a Johann-type bent crystal spectrometer. The observation angle with respect to the beam axis is 54 0 . The interpretation of the spectra is performed by comparing experimental results with Multiconfiguration Dirac-Fock (MCDF) calculated energies and intensities. All the lines are interpreted by 2p - ls transitions (K α spectrum) in excited ions with, respectively, H-, He-, Li-, Be- and B-like electron structures

  15. Metallic aluminum in combustion; Metalliskt aluminium i foerbraenningen

    Energy Technology Data Exchange (ETDEWEB)

    Backman, Rainer; Berg, Magnus; Bostroem, Dan; Hirota, Catherine; Oehman, Marcus; Oehrstroem, Anna

    2007-06-15

    Although aluminum is easily oxidized and melts at temperatures lower than those common in combustion, it can pass through the combustion chamber almost unscathed. If one performs calculations of thermodynamic equilibriums, conditions under which this could happen are extreme in comparison to those generally found in a furnace. Metallic aluminum may yet be found in rather large concentrations in fly ashes. There are also indications that metallic aluminum is present in deposits inside the furnaces. The objectives for the present investigation are better understanding of the behavior of the metallic aluminum in the fuel when it passes through an incinerator and to suggest counter/measures that deal with the problems associated with it. The target group is primary incineration plants using fuel that contains aluminum foil, for example municipal waste, industrial refuse or plastic reject from cardboard recycling. Combustion experiments were performed in a bench scale reactor using plastic reject obtained from the Fiskeby Board mill. First the gas velocity at which a fraction of the reject hovers was determined for the different fuel fractions, yielding a measure for their propensity to be carried over by the combustion gases. Second fractions rich in aluminum foils were combusted with time, temperature and gas composition as parameters. The partially combusted samples were analyzed using SEM/EDS. The degree of oxidation was determined using TGA/DTA. Reference material from full scale incinerators was obtained by collecting fly ash samples from five plants and analyzing them using XRD and SEM/EDS. The results show that thin aluminum foils may easily be carried over from the furnace. Furthermore, it was very difficult to fully oxidize the metallic flakes. The oxide layer on the surface prevents further diffusion of oxygen to the molten core of the flake. The contribution of these flakes to the build of deposits in a furnace is confirmed by earlier investigations in pilot

  16. Capillary self-alignment of mesoscopic foil components for sensor-systems-in-foil

    NARCIS (Netherlands)

    Arutinov, G.; Smits, E.C.P.; Mastrangeli, M.; Heck, G. van; Brand, J. van den; Schoo, H.F.M.; Dietzel, A.H.

    2012-01-01

    This paper reports on the effective use of capillary self-alignment for low-cost and time-efficient assembly of heterogeneous foil components into a smart electronic identification label. Particularly, we demonstrate the accurate (better than 50m) alignment of cm-sized functional foil dies. We

  17. Foil-to-foil lamination and electrical interconnection of printed components on flexible substrates

    NARCIS (Netherlands)

    Vásquez Quintero, A.; Remoortere, B. van; Smits, E.C.P.; Brand, J. van den; Briand, D.; Schoo, H.F.M.; Rooij, N.F. de

    2013-01-01

    This paper describes and compares two integration methods to structurally laminate and interconnect foil-based components with flexible polymeric substrates. The first method uses isotropic conductive adhesives (ICA) confined in laser-ablated through foil vias (TFV), while the second one uses an

  18. Balanced (C_7, C_8)-Foil Designs and Related Designs

    OpenAIRE

    USHIO, Kazuhiko

    2011-01-01

    [Abstract] In graph theory, the decomposition problem of graphs is a very important topic. Various type of decompositions of many graphs can be seen in the literature of graph theory. This paper gives balanced (C_7, C_8)-foil designs, balanced C_15-foil designs, balanced (C_〈14〉, C_〈16〉)-foil designs, balanced C_〈30〉-foil designs, balanced C_45-foil designs, balanced C_〈60〉-foil designs, balanced C_〈75〉-foil designs, balanced C_〈90〉-foil designs, balanced C_〈105〉-foil designs, balanced C_〈120...

  19. Additional security features for optically variable foils

    Science.gov (United States)

    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.

  20. Lifetime measurements on carbon stripper foils

    International Nuclear Information System (INIS)

    Auble, R.L.; Galbraith, D.M.

    1981-01-01

    One of the most exciting recent developments in accelerator technology is the new breed of electrostatic accelerators. These machines have terminal potentials of 25 million volts and higher and are being built to accelerate intense beams of heavy ions. One such accelerator is now nearing completion at ORNL. A crucial component in these--as in any electrostatic accelerator--is a tiny bit of carbon in the form of a very thin foil. These foils, called stripper foils, are used to strip electrons from atoms so that they will be accelerated to high energy by the electrostatic potential. While carbon foils are not the only method of stripping electrons, they have a number of advantages over the alternative gas strippers. In particular, they produce higher charge states which are essential for providing the energetic ions required for heavy ion physics experiments. Because of the importance of stripper foils to the most efficient operation of the new ORNL accelerator, we are quite interested in their properties and in improving their performance

  1. Cryostat with Foil and MLI

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Peter K.F.; Gung, Chen-yu

    2005-10-06

    Induction cores are used to accelerate heavy ion beam array, which are built around the outer diameter of the cryostat housing the superconducting quadruple array. Compact cryostat is highly desirable to reduce the cost of the induction cores. Recent experiences in fabrication of a cryostat for single beam transport revealed that it is possible to reduce the spacing in the cryostat vacuum jacket by using low-emissivity thermal insulation material instead of conventional MLI. However, it is labor-intensive to install the new type of insulation as compared with using MLI. It is promising to build a cost-effective compact cryostat for quadruple magnet array for heavy ion beam array transport by using low-emissivity material combined with conventional MLI as radiation insulation. A matrix of insulation designs and tests will be performed as the feasibility study and for the selection of the optimal thermal insulation as the Phase I work. The selected mixed insulation will be used to build prototype compact cryostats in the Phase II project, which are aiming for housing quadruple doublet array. In this STTR phase I study, a small cryostat has been designed and built to perform calorimetric characterization of the heat load in a liquid helium vessel insulated with a vacuum layer with a nominal clearance of 3.5 mm. The vacuum clearance resembled that used in the warm-bore beam tube region in a prototype cryostat previously built for the heavy ion beam transport experiment. The vacuum clearance was geometrically restricted with a heater shell with the temperature controlled at near 300 K. Various combinations of radiation and thermal shields were installed in the tight vacuum clearance for heat load measurements. The measured heat loads are reported and compared with previous test result using a compact vacuum layer. Further developments of the thermal insulations used in the present study are discussed. The compact cryostat with foil and MLI insulation may be used in the

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

    International Nuclear Information System (INIS)

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

    1992-06-01

    Cobalt foils and stainless steel samples were analyzed for induced 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 22 Na. The results, in addition to the relative sensitivities and precisions afforded by the two methods, are presented

  3. Optofluidic dye laser in a foil

    DEFF Research Database (Denmark)

    Vannahme, Christoph; Christiansen, Mads Brøkner; Mappes, Timo

    2010-01-01

    First order distributed feedback optofluidic dye lasers embedded in a 350 mu m thick TOPAS (R) foil are demonstrated. They are designed in order to give high output pulse energies. Microfluidic channels and first order distributed feedback gratings are fabricated in parallel by thermal nanoimprint...... into a 100 mu m foil. The channels are closed by thermal bonding with a 250 mu m thick foil and filled with 5.10(-3) mol/l Pyrromethene 597 in benzyl alcohol. The fluid forms a liquid core single mode slab waveguide of 1.6 mu m height on a nanostructured grating area of 0.5 x 0.5 mm(2). This results...

  4. Calculation of electron transmission through aluminium foil

    International Nuclear Information System (INIS)

    Abroyan, M.A.; Mel'ker, A.I.; Mikhajlin, A.I.; Sirotinkin, V.V.; Tokmakov, I.L.

    1987-01-01

    Calculated by Monte Carlo method energy and angular distributions of electrons transmitted through aluminium foil with 50 μm thickness are presented. 200-500 electron energy ranges and angles of electron incidence on foil from 0 to 40 deg C are considered. That allows to use results for more universal accelerator group, for example, for accelerators with scanning beam used in industry. The received values of angular and energy characteristics allow to increase essentially estimation accuracy of accelerator extraction devices and dose distribution on irradiating item

  5. Compressor ported shroud for foil bearing cooling

    Science.gov (United States)

    Elpern, David G [Los Angeles, CA; McCabe, Niall [Torrance, CA; Gee, Mark [South Pasadena, CA

    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.

  6. Spallation Neutron Source SNS Diamond Stripper Foil Development

    International Nuclear Information System (INIS)

    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 2 foils as large as 17 x 25 mm 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 - ) where their lifetimes slightly surpassed those of evaporated carbon foils, but fell short of those for Sugai's new hybrid boron carbon (HBC) foils.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ni, P. A.; Bieniosek, F. M.; Logan, B. G. [Lawrence Berkeley National Laboratory, California 94720 (United States); Lund, S. M.; Barnard, J. J.; Bellei, C.; Cohen, R. H. [Lawrence Livermore National Laboratory, California 94551 (United States); McGuffey, C.; Beg, F. N.; Kim, J. [University of California, San Diego, California 92093 (United States); Alexander, N. [General Atomics, San Diego, California 92121 (United States); Aurand, B.; Brabetz, C.; Neumayer, P. [GSI-Darmstadt, Planckstraße 1, 64291 Darmstadt (Germany); Roth, M. [TU-Darmstadt, Karolinenplatz 5, 64289 Darmstadt (Germany)

    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.

  8. Examination of the picture properties of luminescence memory foils

    International Nuclear Information System (INIS)

    Ewert, U.; Heine, S.; Nockemann, C.; Stade, J.; Tillack, G.R.; Wessel, H.; Zscherpel, U.; Mattis, A.

    1995-01-01

    Luminescence memory foils are a new medium for radiography without films. They are known by the name of image plates or digital memory foils. The suitability of such systems for industrial radiography is examined. (orig.) [de

  9. LENA Conversion Foils Using Single-Layer Graphene, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Our key innovation will be the use of single-layer graphene as LENA conversion foils, with appropriate microgrids and nanogrids to support the foils. Phase I...

  10. Hydrogen and Palladium Foil: Two Classroom Demonstrations

    Science.gov (United States)

    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…

  11. 6Li foil thermal neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Ianakiev, Kiril D [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Favalli, Andrea [Los Alamos National Laboratory; Chung, Kiwhan [Los Alamos National Laboratory; Macarthur, Duncan W [Los Alamos National Laboratory

    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.

  12. The Fluid Foil: The Seventh Simple Machine

    Science.gov (United States)

    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,…

  13. Vortex wakes of a flapping foil

    DEFF Research Database (Denmark)

    Schnipper, Teis; Andersen, Anders Peter; Bohr, Tomas

    2009-01-01

    We present an experimental study of a symmetric foil performing pitching oscillations in a vertically flowing soap film. By varying the frequency and amplitude of the oscillation we visualize a variety of wakes with up to 46 vortices per oscillation period, including von Karman vortex street, inv...

  14. Thermal Sensitive Foils in Physics Experiments

    Science.gov (United States)

    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…

  15. Beam-foil study of neon in the EUV with foils of carbon, silver and gold

    International Nuclear Information System (INIS)

    Demarest, J.A.; Watson, R.L.; Texas A and M Univ., College Station

    1988-01-01

    A beam-foil study of 40 MeV neon was conducted in the EUV with a 1-meter grazing incidence spectrometer configured with a position sensitive microchannel plate detector. A number of new lines of Ne IX, mainly from transitions to n = 3 levels, were detected in the wavelength region covering 50-350 A. Comparison of the spectra obtained using the different foils revealed that the average charge state of the neon projectiles was nearly one unit higher with carbon than with either of the two metals. Measurements of line intensities versus distance from the foils showed that cascade contributions were greatly reduced for the metals. It was also found that n = 3 states of low l were overpopulated relative to a statistical distribution, irrespective of the foil material. (orig.)

  16. Identification of dynamic properties of radial air-foil bearings

    NARCIS (Netherlands)

    Arora, Vikas; Arora, V.; van der Hoogt, Peter; Aarts, Ronald G.K.M.; de Boer, Andries

    2010-01-01

    Air-foil bearings (AFBs) 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 the layer or layers underneath provide an elastic foundation. Air-foil bearings are

  17. Orientation and alignment in beam tilted-foil spectroscopy

    International Nuclear Information System (INIS)

    Berry, H.G.

    1976-01-01

    The production of atomic orientation and alignment, by anisotropic excitation is analyzed. The stokes parameters of the light emitted from tilted-foil excited ions provide measurements of orientation and alignment, and some examples are given. The variations of the stokes parameters with foil tilt angle, excited state, ion velocity and foil material are compared with existing theories

  18. Stripping foils for the PSB H- injection system

    CERN Document Server

    Aiba, M; Goddard, B; Weterings, W

    2009-01-01

    Beam physics considerations for the stripping foil of the PSB H- injection system are described, including the arguments for the foil type, thickness, geometry and positioning. The foil performance considerations are described, including expected stripping efficiency, emittance growth, energy straggling, temperature and lifetime. The required movement ranges and tolerances are detailed, together with the assumptions used.

  19. Recycling of automotive aluminum

    OpenAIRE

    Cui, Jirang; Roven, Hans Jørgen

    2010-01-01

    With the global warming of concern, the secondary aluminum stream is becoming an even more important component of aluminum production and is attractive because of its economic and environmental benefits. In this work, recycling of automotive aluminum is reviewed to highlight environmental benefits of aluminum recycling, use of aluminum alloys in automotive applications, automotive recycling process, and new technologies in aluminum scrap process. Literature survey shows that newly developed t...

  20. Scaling laws for radial foil bearings

    Science.gov (United States)

    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

  1. Fabrication and characterization of stable superhydrophobic surface with good friction-reducing performance on Al foil

    Energy Technology Data Exchange (ETDEWEB)

    Li, Peipei [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Chen, Xinhua, E-mail: xuc0374@hotmail.com [College of Chemistry and Chemical Engineering, Xuchang University, Xuchang 461000 (China); Yang, Guangbin; Yu, Laigui [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Zhang, Pingyu, E-mail: pingyu@henu.edu.cn [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China)

    2014-05-01

    Graphical abstract: A lotus-leaf-like hierarchical structure was successfully created on Al foil by a facile three-step solution–immersion method. As-obtained etched-immersed Al/STA rough surface contains interconnected convex–concave micro-structure and uniformly distributed nano-sheets that endow the surface with excellent superhydrophobicity (WCA: 164.2°; WSA: below 5°). Besides, the as-prepared etched-immersed Al/STA superhydrophobic surface on Al foil exhibits good friction-reducing ability and stable superhydrophobicity. - Highlights: • A stable superhydrophobic surface was created on aluminum foil by a facile three-step solution–immersion method. • A lotus-leaf-like hierarchical structure consists of interconnected convex–concave micro-structure and uniformly distributed nano-sheets has been constructed on the aluminum surface. • The superhydrophobic surfaces on aluminum substrate showing effective friction-reducing performance and self-cleaning ability. - Abstract: A lotus-leaf-like hierarchical structure with superhydrophobicity was created on Al foil by a facile three-step solution–immersion method involving etching in hydrochloric acid solution and immersing in hot water as well as surface-modification by stearic acid (denoted as STA). As-prepared etched-immersed Al/STA rough surface was characterized by means of scanning electron microscopy and X-ray photoelectron spectroscopy. Moreover, the water contact angles and water sliding angles of as-prepared etched-immersed Al/STA rough surface were measured, and the friction-reducing performance and self-cleaning ability of the as-prepared surface were also evaluated. Results indicate that the etched-immersed Al/STA rough surface consists of interconnected convex–concave micro-structure and uniformly distributed nano-sheets. Besides, it exhibits stable superhydrophobicity and good friction-reducing ability. Namely, it has a contact angle of water as high as 164.2° and a water sliding

  2. Carbon stripper foils held in place with carbon fibers

    International Nuclear Information System (INIS)

    Jolivet, Connie S.; Miller, Shawn A.; Stoner, John O.; Ladd, Peter

    2008-01-01

    The Spallation Neutron Source (SNS) currently under construction at Oak Ridge National Laboratory, Oak Ridge, Tennessee, is planned to initially utilize carbon stripper foils having areal densities approximately 260 μg/cm 2 . The projected design requires that each foil be supported by only one fixed edge. For stability of the foil, additional support is to be provided by carbon fibers. The feasibility of manufacturing and shipping such mounted carbon foils produced by arc evaporation was studied using two prototypes. Production of the foils is described. Fibers were chosen for satisfactory mechanical strength consistent with minimal interference with the SNS beam. Mounting of the fibers, and packaging of the assemblies for shipping are described. Ten completed assemblies were shipped to SNS for further testing. Preliminary evaluation of the survivability of the foils in the SNS foil changer is described

  3. Advances in targetry with thin diamond-like carbon foils

    CERN Document Server

    Liechtenstein, V K; Olshanski, E D; Repnow, R; Levin, J; Hellborg, R; Persson, P; Schenkel, T

    2002-01-01

    Thin and stable diamond-like carbon (DLC) foils, which were fabricated at the Kurchatov Institute by sputter deposition, have proved recently to be advantageous for stripping and secondary electron timing of high energy heavy ions in a number of accelerator experiments. This resulted in expanding applications of these DLC foils which necessitated further development efforts directed toward the following applications of DLC targetry: (i) thin stripper foils for lower energy tandem accelerators, (ii) enlarged (up to 66 mm in diameter) stop foils for improved time-of-flight elastic recoil detection ion beam analysis, and (iii) ultra-thin (about 0.6 mu g/cm sup 2) DLC foils for some fundamental and applied physics experiments. Along with the fabrication of thin DLC stripper foils for tandem accelerators, much thicker (up to 200 mu g/cm sup 2) foils for post-stripping of heavy-ion beams in higher energy linacs, are within reach.

  4. Viscous investigation of a flapping foil propulsor

    Science.gov (United States)

    Posri, Attapol; Phoemsapthawee, Surasak; Thaweewat, Nonthipat

    2018-01-01

    Inspired by how fishes propel themselves, a flapping-foil device is invented as an alternative propulsion system for ships and boats. The performance of such propulsor has been formerly investigated using a potential flow code. The simulation results have shown that the device has high propulsive efficiency over a wide range of operation. However, the potential flow gives good results only when flow separation is not present. In case of high flapping frequency, the flow separation can occur over a short instant due to fluid viscosity and high angle of attack. This may cause a reduction of propulsive efficiency. A commercial CFD code based on Lattice Boltzmann Method, XFlow, is then employed in order to investigate the viscous effect over the propulsive performance of the flapping foil. The viscous results agree well with the potential flow results, confirming the high efficiency of the propulsor. As expected, viscous results show lower efficiency in high flapping frequency zone.

  5. Composite metal foil and ceramic fabric materials

    Science.gov (United States)

    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.

  6. Brazing Inconel 625 Using the Copper Foil

    Science.gov (United States)

    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.

  7. Monitoring the degradation of partly decomposable plastic foils

    Directory of Open Access Journals (Sweden)

    Rétháti Gabriella

    2014-11-01

    Full Text Available We have monitored the behaviour of different polyethylene foils including virgin medium density polyethylene (MDPE, MDPE containing pro-oxydative additives (238, 242 and MDPE with pro-oxydative additives and thermoplastic starch (297 in the soil for a period of one year. A foil based on a blend of polyester and polylactic acid (BASF Ecovio served as degradable control. The experiment was carried out by weekly measurements of conductivity and capacity of the soil, since the setup was analogous to a condenser, of which the insulating layer was the foil itself. The twelve replications allowed monthly sampling; the specimen taken out from the soil each month were tested visually for thickness, mechanical properties, morphological and structural changes, and molecular mass. Based on the obtained capacity values, we found that among the polyethylene foils, the one that contained thermoplastic starch extenuated the most. This foil had the greatest decrease in tensile strength and elongation at break due to the presence of thermoplastic starch. The starch can completely degrade in the soil; thus, the foil had cracks and pores. The polyethylene foils that contained pro-oxydant additives showed smaller external change compared to the virgin foil, since there was no available UV radiation and oxygen for their degradation. The smallest change occurred in the virgin polyethylene foil. Among the five examined samples, the commercially available BASF foil showed the largest extenuation and external change, and it deteriorated the most in the soil.

  8. Foil changer for the Chalk River superconducting cyclotron

    International Nuclear Information System (INIS)

    Hoffmann, C.R.; Kilborn, R.I.; Mouris, J.E.; Proulx, D.R.; Weaver, J.F.

    1985-01-01

    Capture of an injected beam in the Chalk River superconducting cyclotron requires that a carbon stripping foil be accurately placed in a dee to intercept the incoming beam. Foil radial position must be precisely adjustable and foils must be easily replaced. A foil changing apparatus has been designed, built and tested to meet these requirements. The main components are a supply magazine, a transport system, and unloading and loading mechanisms. The magazine is on top of the cyclotron. It holds 300 foils and can be isolated from machine vacuum for refilling. Each foil is mounted on a stainless steel frame. A stainless steel roller chain fitted with 33 copper sleeves (shrouds) carries foils, one per shroud, down a dee stem to the midplane. A 12-bit absolute optical shaft encoder senses foil position. To replace a foil a shroud is positioned at the top of the cyclotron, a foil is removed, and another is transferred from the magazine to the empty shroud. Three stepping motors and associated electronics provide mechanical drive and are interfaced with a CAMAC control system

  9. High speed fabrication of aluminum nanostructures with 10 nm spatial resolution by electrochemical replication.

    Science.gov (United States)

    Biring, Sajal; Tsai, Kun-Tong; Sur, Ujjal Kumar; Wang, Yuh-Lin

    2008-09-03

    A high fidelity electrochemical replication technique for the rapid fabrication of Al nanostructures with 10 nm lateral resolution has been successfully demonstrated. Aluminum is electrodeposited onto a lithographically patterned Si master using a non-aqueous organic hydride bath of aluminum chloride and lithium aluminum hydride at room temperature. Chemical pretreatment of the Si surface allows a clean detachment of the replicated Al foil from the master, permitting its repetitive use for mass replication. This high throughput technique opens up new possibilities in the fabrication of Al-related nanostructures, including the growth of long range ordered anodic alumina nanochannel arrays.

  10. Collision Welding of Dissimilar Materials by Vaporizing Foil Actuator: A Breakthrough Technology for Dissimilar Metal Joining

    Energy Technology Data Exchange (ETDEWEB)

    Daehn, Glenn S. [The Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering; Vivek, Anupam [The Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering; Liu, Bert C. [The Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

    2016-09-30

    This work demonstrated and further developed Vaporizing Foil Actuator Welding (VFAW) as a viable technique for dissimilar-metal joining for automotive lightweighting applications. VFAW is a novel impact welding technology, which uses the pressure developed from electrically-assisted rapid vaporization of a thin aluminum foil (the consumable) to launch and ultimately collide two of more pieces of metal to create a solid-state bond between them. 18 dissimilar combinations of automotive alloys from the steel, aluminum and magnesium alloy classes were screened for weldability and characterized by metallography of weld cross sections, corrosion testing, and mechanical testing. Most combinations, especially a good number of Al/Fe pairs, were welded successfully. VFAW was even able to weld combinations of very high strength materials such as 5000 and 6000 series aluminum alloys to boron and dual phase steels, which is difficult to impossible by other joining techniques such as resistance spot welding, friction stir welding, or riveting. When mechanically tested, the samples routinely failed in a base metal rather than along the weld interface, showing that the weld was stronger than either of the base metals. As for corrosion performance, a polymer-based protective coating was used to successfully combat galvanic corrosion of 5 Al/Fe pairs through a month-long exposure to warm salt fog. In addition to the technical capabilities, VFAW also consumes little energy compared to conventional welding techniques and requires relatively light, flexible tooling. Given the technical and economic advantages, VFAW can be a very competitive joining technology for automotive lightweighting. The success of this project and related activities has resulted in substantial interest not only within the research community but also various levels of automotive supply chain, which are collaborating to bring this technology to commercial use.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. Stresses in the foil of an electron accelerator extraction channel

    International Nuclear Information System (INIS)

    Abroyan, M.A.; Makarenko, T.I.; Tokmakov, I.L.

    1983-01-01

    Stresses in the foil of an electron accelerator extraction channel are assessed with account of contributions of thermal expansion and stress concentrations during switchings. Optimization of extraction grid parameters of the electron accelerator extraction channel and choice of foil material for high current electron beam is conducted. It is suggested that an extraction grid with circular cells and Al-Mg foil should be used. A simple formula applicable for design calculations is proposed for evaluation of stress concentration coefficient during phase switchings

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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%.

  18. LENA Conversion Foils Using Single-Layer Graphene, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Implementing graphene foils in existing neutral atom detector designs will increase their angular and energy resolution, and also improve their mass discrimination...

  19. Foil focusing of relativistic electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Jr., Carl August [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-26

    When an intense relativistic electron beams (IREB) passes through a grounded metal foil, the transverse electric field due to the beam space charge is locally shorted out, and the beam is focused by the magnetic field of its current. The effect can be treated as focusing by a thin lens with first order aberration. Expressions for the focal length and aberration coefficient of the equivalent thin lens are developed in this note. These are then applied to practical examples representative of IREB research at Los Alamos National Laboratory.

  20. The Los Alamos foil implosion project

    International Nuclear Information System (INIS)

    Brownell, J.; Parker, J.; Bartsch, R.; Benage, J.; Bowers, R.; Cochrane, J.; Forman, P.; Goforth, J.; Greene, A.; Kruse, H.

    1993-01-01

    The goal of the Los Alamos foil implosion project is to produce an intense (>100 TW), multi-megajoule, laboratory soft x-ray source for material studies and fusion experiments. The concept involves the implosion of annular, current-carrying, cylindrical metallic plasmas via their self-magnetic forces. The project features inductive storage systems using both capacitor banks and high explosive-driven flux compression generators as prime energy sources. Fast opening switches are employed to shorten the electrical pulses. The program will be described and activities to date will be summarized

  1. Fine Grain Aluminum Superplasticity

    Science.gov (United States)

    1980-02-01

    Continua on ravaraa sida H nacaaaary and identify by block numbar) Superplastic aluminum, Superplasticity, Superplastic forming. High strength aluminum...size. The presence of precipitate particles also acts to impede grain boundary migration during recrystallization, further aiding in maintaining a

  2. Actinide Foil Production for MPACT Research

    Energy Technology Data Exchange (ETDEWEB)

    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

  3. ALUMINUM BOX BUNDLING PRESS

    Directory of Open Access Journals (Sweden)

    Iosif DUMITRESCU

    2015-05-01

    Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

  4. Design and optimization of vertex detector foils by superplastic forming

    NARCIS (Netherlands)

    Snippe, Q.H.C.

    2011-01-01

    The production of one of the parts in a particle detector, called the RF Foil, has been a very intensive process in the past. The design and production process, which had a trial and error character, led eventually to an RF Foil that met the most important requirement: a sufficient leak tightness

  5. Foil fabrication for the ROMANO event. Revision 1

    International Nuclear Information System (INIS)

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

    1984-01-01

    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

  6. Practical and research aspects of beam-foil spectroscopy

    International Nuclear Information System (INIS)

    Bashkin, S.

    1974-01-01

    Practical aspects of the application of low-energy accelerators to research in beam-foil spectroscopy are discussed, and the kinds of equipment and associated costs are described in some detail. Some typical beam-foil experiments, emphasizing the most recent studies, are treated so as to show how relatively simple facilities can be used to produce physics of great interest

  7. Lithographic patterning of metals on flexible plastic foils

    NARCIS (Netherlands)

    Peter, M.; Furthner, F.; Deen, J.; Laat, W.J.M.de; Meinders, E.R.

    2009-01-01

    In this paper the challenges of patterning electrodes with separations in the micron and sub-micron range onto thin polyethylene naphthalate foils for use in biochips are discussed. It was found that it was necessary to improve the adhesion of the metal electrodes to the foil by using plasma

  8. Conference Interpreters

    DEFF Research Database (Denmark)

    Leal Lobato, Ana Isabel

    2017-01-01

    Conference Interpreters: How to serve the cause of minorized communities in the new postmonolingual / ‘postmonodiscoursive’ order,......Conference Interpreters: How to serve the cause of minorized communities in the new postmonolingual / ‘postmonodiscoursive’ order,...

  9. Characterization of the water diffusion in GEM foil material

    Science.gov (United States)

    Benussi, L.; Bianco, S.; Saviano, G.; Muhammad, S.; Piccolo, D.; Raffone, G.; Caponero, M.; Passamonti, L.; Pierluigi, D.; Russo, A.; Primavera, F.; Cerbelli, S.; Lalli, A.; Valente, M.; Ferrini, M.; Teissandier, B.; Taborelli, M.; Parvis, M.; Grassini, S.; Tirilló, J.; Sarasini, F.; Franchi, A. V.

    2018-02-01

    Systematic studies on the GEM foil material are performed to measure the moisture diffusion rate and saturation level. These studies are important because the presence of this compound inside the detector' s foil can possibly change its mechanical and electrical properties, and in such a way, the detector performance can be affected. To understand this phenomenon, a model is developed with COMSOL Multiphysics v. 4.3 [1], which described the adsorption and diffusion within the geometry of GEM foil, the concentration profiles and the time required to saturate the foil. The COMSOL model is verified by experimental observations on a GEM foil sample. This note will describe the model and its experimental verification results.

  10. Aluminum reference electrode

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cummins, Dustin Ray [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vogel, Sven C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hollis, Kendall Jon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Donald William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dombrowski, David E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    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

  12. Gas Foil Bearing Misalignment and Unbalance Effects

    Science.gov (United States)

    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

  13. Thin foil expansion into a vacuum

    International Nuclear Information System (INIS)

    Mora, P.

    2005-01-01

    Plasma expansion into a vacuum is an old problem which has been renewed recently in various contexts: expansion of ultra-cold plasmas, cluster expansion, of dust grains, expansion of thin foils. In this presentation I will first discuss the physics of the expansion of a thin foil irradiated by an ultra-short ultra-intense laser pulse. The expansion results in the formation of high energy ions. For an infinitely steep plasma-vacuum interface the fastest ions are located in the outer part of the expansion and their velocity is given by ν m ax∼ 2 C s (In ω p it) where c s (Zk B T e /m i )''1/2 is the ion-acoustic velocity ω p i=(n e 0Ze''2/m i e 0 )''1/2 is the ion plasma frequency, n e 0 is the electron density in the unperturbed plasma, Z is the ion charge number. In the above expression, t is either the pulse duration or the effective acceleration time (in particular t∼L/2c s , where L is the width of the foil, when the electron cooling is taken into account). A salient characteristic of the expansion is the occurrence of a double layer structure and a peak of the accelerating electric field at the ion front. I will explain the origin of the peak and predict its temporal behavior. This peak has been diagnosed in recent experiments. I will also discuss the effect of a 2-temperatures electron distribution function on the expansion, showing the dominant role of the hot electron component. Finally I will discuss the occurrence of ion spikes in the expansion when the initial density profile is smooth. The ion spike is due to a wave breaking which cannot be handled in a satisfactory way by a fluid code and requires a kinetic description. A. simple collisionless particle code has been used to treat the evolution of the spike after the wave breaking and the results will be shown. (Author)

  14. Design considerations for foil windows for PET radioisotope targets

    International Nuclear Information System (INIS)

    Hughey, B.J.; Shefer, R.E.; Klinkowstein, R.E.; Welch, M.J.

    1992-01-01

    This paper describes the results of a study performed at SRL to develop analytical and computational techniques for optimizing the design of conduction-cooled foil windows for PET targets. Single foil conduction cooled windows have been found to be good target entrance windows for both low energy accelerators and medium energy cyclotrons. Detailed thermal analysis has given an approximate analytical expression for the maximum temperature reached in a foil window under conditions of realistic ion beam bombardment. The effects of 'hot spots' in the beam density profile were investigated. It was shown that a factor of two safety margin in window design should be adequate to compensate for any possible beam hot spots. In addition, the reduction of foil stress by slack mounting was verified by experiments. The properties of conventional and novel foil materials were investigated for use in conduction cooled windows. Novel foil materials include two-component Al/Ti and Al/Havar foil. Results on the testing of candidate foil materials for thermal conductivity and mechanical strength at elevated temperature were presented. Two optimum foil window geometries were analyzed: a high aspect ratio window and a multiply slotted window. The multiply slotted window combines the advantages of a high aspect ratio foil window with a circular beam strike and is a promising window design for both TCA and cyclotron targets. A multiply slotted window for a N 2 gas target for 15 O production was designed using the methodologies discussed above. This prototype target was successfully tested using the TCA beam at SRL. (author) 6 figs., 3 tabs., 10 refs

  15. Foil Gas Thrust Bearings for High-Speed Turbomachinery

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  18. {beta}-nmr of Palladium foil

    Energy Technology Data Exchange (ETDEWEB)

    Parolin, T.J. [Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Salman, Z. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Chakhalian, J. [Max-Plank Institute for Solid State Research, D-70569 Stuttgart (Germany); Wang, D. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Keeler, T.A. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Hossain, Md. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Kiefl, R.F. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Canadian Institute for Advanced Research (Canada); Chow, K.H. [Department of Physics, University of Alberta, Edmonton, AB, T6G 2J1 (Canada); Morris, G.D. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Miller, R.I. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); MacFarlane, W.A. [Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada)]. E-mail: wam@chem.ubc.ca

    2006-03-31

    Beta-detected NMR ({beta}-nmr) of low-energy implanted {sup 8}Li{sup +} was studied in metallic palladium. The resonance was found to have a large negative shift with respect to the reference signal in the cubic insulator MgO. This shift exhibited significant temperature dependence on cooling below room temperature, approximately proportionate to the temperature-dependent spin susceptibility of pure Pd. Thus it is tentatively attributed to a Knight shift (K) caused by a large negative hyperfine coupling; a phenomenon common in transition metal ions, but not in alkalis. However, the spin-lattice relaxation of {sup 8}Li is much slower than expected from the Korringa law for such a large K. We compare results from samples of very different thicknesses: 12.5{mu}m foil and a 100nm thin film.

  19. Preparation of selenium coatings onto beryllium foils

    International Nuclear Information System (INIS)

    Erikson, E.D.; Tassano, P.L.; Reiss, R.H.; Griggs, G.E.

    1984-09-01

    A technique for preparing selenium films onto 50.8 microns thick beryllium foils is described. The selenium was deposited in vacuum from a resistance heated evaporation source. Profilometry measurements of the coatings indicate deposit thicknesses of 5.5, 12.9, 37.5, 49.8 and 74.5 microns. The control of deposition rate and of coating thickness was facilitated using a commercially available closed-loop programmable thin film controller. The x-ray transmission of the coated substrates was measured using a tritiated zirconium source. The transmissivities of the film/substrate combination are presented for the range of energies from 4 to 20 keV. 15 references, 3 figures

  20. Optical and electrical experiments at some transition-metal oxide foil-electrolyte interfaces

    International Nuclear Information System (INIS)

    Sari, S.O.; Ahlgren, W.L.

    1977-01-01

    Metal-oxide layers formed from transition-metal foils oxidized by heating in air have been examined for their photoelectrolytic response. The metals examined are Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, and Pt. Weak photoeffects are observed for oxide layers of all of these metals. Sizable light-dependent oxygen gas evolution rates are found in Ti and also in W oxides. The spectral dependence of the oxygen response in these compounds is investigated, and interpretation is given of these experiments

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Rolling and pitching oscillating foil propulsion in ground effect.

    Science.gov (United States)

    Perkins, Matthew D; Elles, Dane; Badlissi, George; Mivehchi, Amin; Dahl, Jason; Licht, Stephen

    2017-09-04

    In this paper, we investigate the effect of operating near a solid boundary on the forces produced by harmonically oscillating thrust generating foils. A rolling and pitching foil was towed in a freshwater tank in a series of experiments with varying kinematics. Hydrodynamic forces and torques were measured in the free stream and at varying distances from a solid boundary, and changes in mean lift and thrust were found when the foil approached the boundary. The magnitude of this ground effect exhibited a strong nonlinear dependence on the distance between the foil and the boundary. Significant effects were found within three chord lengths of the boundary, and ground effect can be induced at greater distances from the boundary by biasing the tip of the foil toward the boundary. Lift coefficients changed by as much as 0.2 at the closest approach to the ground, with changes ≥0.05 for all cases across Strouhal number ranging from 0.3 to 0.6, and nominal maximum angle of attack ranging from 20° to 40°. The ubiquity of the ground effect in high thrust kinematics suggests that the ground effect can provide a passive obstacle avoidance capability for foil propelled vehicles. By comparison to previous experimental work, we find that the ground effect experienced by a high-aspect ratio rolling and pitching foil is a fully three-dimensional phenomenon, as it is not accurately predicted when two-dimensional flow and/or two-dimensional kinematics are enforced. While two dimensional foil kinematics are more easily modeled for numerical studies, three-dimensional foil kinematics may be more practical for real world implementation in underwater vehicles. © 2017 IOP Publishing Ltd.

  4. Physical and Electrical Characterization of Aluminum Polymer Capacitors

    Science.gov (United States)

    Liu, David (Donghang)

    2010-01-01

    Conductive polymer aluminum capacitor (PA capacitor) is an evolution of traditional wet electrolyte aluminum capacitors by replacing liquid electrolyte with a solid, highly conductive polymer. On the other hand, the cathode construction in polymer aluminum capacitors with coating of carbon and silver epoxy for terminal connection is more like a combination of the technique that solid tantalum capacitor utilizes. This evolution and combination result in the development of several competing capacitor construction technologies in manufacturing polymer aluminum capacitors. The driving force of this research on characterization of polymer aluminum capacitors is the rapid progress in IC technology. With the microprocessor speeds exceeding a gigahertz and CPU current demands of 80 amps and more, the demand for capacitors with higher peak current and faster repetition rates bring conducting polymer capacitors to the center o( focus. This is because this type of capacitors has been known for its ultra-low ESR and high capacitance. Polymer aluminum capacitors from several manufacturers with various combinations of capacitance, rated voltage, and ESR values were obtained and tested. The construction analysis of the capacitors revealed three different constructions: conventional rolled foil, the multilayer stacking V-shape, and a dual-layer sandwich structure. The capacitor structure and its impact on the electrical characteristics has been revealed and evaluated. A destructive test with massive current over stress to fail the polymer aluminum capacitors reveals that all polymer aluminum capacitors failed in a benign mode without ignition, combustion, or any other catastrophic failures. The extraordinary low ESR (as low as 3 mOMEGA), superior frequency independence reported for polymer aluminum capacitors have been confirmed. For the applications of polymer aluminum capacitors in space programs, a thermal vacuum cycle test was performed. The results, as expected, show no

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

    International Nuclear Information System (INIS)

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

    1999-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Interpretive Journalism

    OpenAIRE

    Salgado, Susana; Strömbäck, Jesper; Aalberg, Toril; Esser, Frank

    2017-01-01

    In summary one-third of the political coverage analyzed in the 16 countries was found to contain interpretive journalism, with some countries - including France and the United States - making use of it much more than the rest. Indeed, the story genres and the interpretive journalism used in the various countries differ substantially, indicating distinct motives and news cultures. A multivariate analysis conducted to identify the most powerful predictors of interpretive journ...

  8. A novel carbon coating technique for foil bolometers.

    Science.gov (United States)

    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.

  9. Preparation of self-supporting metallic foils of nickel isotopes

    International Nuclear Information System (INIS)

    Sugai, Isao.

    1975-01-01

    This is the fourth report on the practical methods of target preparation for use in low energy nuclear experiments following the previous one (INS-J-150). An electroplating method has been developed as a dependable and reproducible technique for making self-supporting metallic foils of nickel in the thickness range of 0.5 to 10 mg/cm 2 . The procedures minimized the necessary amount of material so that nickel isotopes could be processed economically. Impurity contamination of the nickel foils during the electroplating process was less than 500 ppm, and the thickness variation in each foil was less than 3% of the central thickness. (auth.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Schulthess, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    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.

  11. Method of fabricating a uranium-bearing foil

    Science.gov (United States)

    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.

  12. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Elimination of aluminum adjuvants.

    Science.gov (United States)

    Hem, Stanley L

    2002-05-31

    In vitro dissolution experiments although perhaps not at typical body concentrations and temperatures demonstrated that the alpha-hydroxycarboxylic acids present in interstitial fluid (citric acid, lactic acid, and malic acid) are capable of dissolving aluminum-containing adjuvants. Amorphous aluminum phosphate adjuvant dissolved more rapidly than crystalline aluminum hydroxide adjuvant. Intramuscular administration in New Zealand White rabbits of aluminum phosphate and aluminum hydroxide adjuvants, which were labelled with 26Al, revealed that 26Al was present in the first blood sample (1 h) for both adjuvants. The area under the blood level curve for 28 days indicated that three times more aluminum was absorbed from aluminum phosphate adjuvant than aluminum hydroxide adjuvant. In vivo studies using 26Al-labelled adjuvants are relatively safe because accelerator mass spectrometry (AMS) can quantify quantities of 26Al as small as 10(-17) g. A similar study in humans would require a whole-body exposure of 0.7 microSv per year compared to the natural background exposure of 3000 microSv per year. The in vitro dissolution and in vivo absorption studies indicate that aluminum-containing adjuvants which are administered intramuscularly are dissolved by alpha-hydroxycarboxylic acids in interstitial fluid, absorbed into the blood, distributed to tissues, and eliminated in the urine.

  14. 21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

    Science.gov (United States)

    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 barrier...

  15. Finite Element Modelling of Bends and Creases during Folding Ultra Thin Stainless Steel Foils

    NARCIS (Netherlands)

    Datta, K.; Akagi, H.; Geijselaers, Hubertus J.M.; Huetink, Han

    2003-01-01

    Finite Element Modelling of an ultra thin foil of SUS 304 stainless steel is carried out. These foils are 20 mm and below in thickness. The development of stresses and strains during folding of these foils is studied. The objective of this study is to induce qualities of paper in the foils of

  16. Controlled electropolishing of copper foils at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Gi Duk; Kim, Young Woo; Moyen, Eric; Keum, Dong Hoon [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Young Hee [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); IBS Center for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Daejeon (Korea, Republic of); Department of Physics, Sungkyunkwan Advanced Institute of Nano-technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Baik, Seunghyun [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); IBS Center for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Daejeon (Korea, Republic of); Pribat, Didier, E-mail: didier53@skku.edu [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-07-01

    We have studied the electrochemical polishing of copper foils at elevated temperature, in H{sub 3}PO{sub 4} electrolytes of various concentrations. Atomic force microscopy, surface reflectance measurements as well as optical microscopy and scanning electron microscopy (including electron backscattering diffraction) have been used throughout this study to characterize the surface of the electropolished foils. We have found that copper foils electropolished at 65 °C in 2.17 M H{sub 3}PO{sub 4}, exhibited a lower surface roughness and a higher percent specular reflection, comparing with values obtained after classical electropolishing in concentrated H{sub 3}PO{sub 4} at room temperature or comparing with values obtained after chemical-mechanical polishing. This work could open up new prospects for the preparation of copper foils before the growth of high quality graphene layers.

  17. A study of molecular effects in beam-foil spectroscopy

    International Nuclear Information System (INIS)

    Andresen, B.; Veje, E.

    1979-01-01

    Relative populations of ns + nd levels in hydrogen as functions of the principal quantum number n have been measured with beams of H + , H 2 + , and H 3 + impinging on thin carbon foils at 25 keV/amu and 100 keV/amu. Enhancements of 20% and 45% for dimer and trimer clusters are observed uniformly for all levels. A possible explanation in terms of screening of the Coulomb repulsion between the protons inside the foil, thus reducing the effective thickness of the foil, is given. All relative populations closely follow an nsup(P) power law with p = -4.0 and -3.7 at 25 keV/amu and 100 keV/amu, respectively, in perfect analogy with atomic collision experiments. O + /O 2 + -foil excitations at 100 keV and 155 keV show a simular molecular effect, but in reverse with a larger mean charge produced by the dimer. (Auth.)

  18. A procedure for rapid evaluation of carbon stripper foils

    International Nuclear Information System (INIS)

    Auble, R.L.; Galbraith, D.M.

    1982-01-01

    Lifetime measurements on carbon foils can become prohibitively time consuming and expensive with conventional particle accelerator beams. Therefore, a method has been developed which utilizes a beam of low energy (20 keV) nitrogen ions which allows tests to be conducted on relatively inexpensive equipment at very high damage rates. The beam is obtained from a General Ionex Model 1080 Sputterbell. Beam currents of the order of 1 μA cm -2 lead to failure of glow-discharge type foils on a time scale of, typically, 5-10 min. Lifetime ratios for glow-discharge versus evaporated foils obtained with this technique are in good agreement with those obtained with higher energy beams. Relative lifetimes for high energy and low energy bombardments are also found to be in good agreement with those predicted by damage energy calculations. The technique is currently being applied to the testing of glow discharge foils made with different feed gases and discharge conditions. (orig.)

  19. Decontamination with pasty pickling agents forming a strippable foil

    International Nuclear Information System (INIS)

    Weichselgartner, H.

    1991-01-01

    This paper describes the development of an in-situ decontamination procedure by applying onto the contaminated surface (in an one-step or multi-step process) pasty, chemically aggressive agents causing dilution and adsorption of the contaminant and then hardening to form a strippable foil. The use of such a foil will result in following advantages, with respect to usual techniques: - sensibly shorter operation duration resulting in lower personnel doses; - reduction of the arising secondary waste volume because there is no need for washing; the volume of the spent strippable foil is much smaller than currently used water volumes; - optimal conditioning of the radioactive waste due to its fixation in a solid (foil); - an accidental contamination in a controlled area can easily be fixed and covered avoiding its propagation

  20. Practical and research aspects of beam-foil spectroscopy

    International Nuclear Information System (INIS)

    Bashkin, S.

    1975-01-01

    The application of a heavy-ion accelerator to research in beam-foil spectroscopy requires certain capital equipment which is somewhat unorthodox when viewed from the standpoint of conventional, low-energy nuclear physics. It is necessary that people who wish to expand their accelerator work to include beam-foil studies understand the nature and cost of such major apparatus. We will survey the equipment needs, starting with the particle analyzer at the output of the accelerator and including the equipment used in a variety of beam-foil experiments. Electronic and computer devices will not be discussed since they are essentially identical with those employed in nuclear studies. Considerable attention will be given to optical spectrometers and spectographs including simple instruments which might be used by a laboratory just getting started in beam-foil research, or which has limited financial resources. Attention will be given to the production and use of the exciter foils. We will then discuss some typical beam-foil experiments having to do with the excitation, detection, and analysis of spectral lines from electronic levels in multiply-ionized atoms, and also with the measurement of the mean lives of such levels. Finally, we will review some of the special properties of the beam-foil light source as regards the population of the magnetic sub-states of a given level. Recent work on the character of the emitted light will be presented. That work will deal specifically with the origin of the polarization of the light. The relevant experiments involve varying the angle between the plane of the exciter foil and the particle velocity. (author)

  1. Alignment and orientation effects in beam-foil experiments

    International Nuclear Information System (INIS)

    Band, Y.B.

    1975-01-01

    A theory of the orientation and alignment of atoms observed upon emergence from tilted foils is presented. The interaction with the foil surface is taken into account in the production process of particular states. Once they are produced, the evolution of these states, under the influence of the residual field near the surface, is calculated in the fashion introduced by Eck. The most general effect of this evolution is presented

  2. Interpretation miniatures

    Science.gov (United States)

    Nikolić, Hrvoje

    Most physicists do not have patience for reading long and obscure interpretation arguments and disputes. Hence, to attract attention of a wider physics community, in this paper various old and new aspects of quantum interpretations are explained in a concise and simple (almost trivial) form. About the “Copenhagen” interpretation, we note that there are several different versions of it and explain how to make sense of “local nonreality” interpretation. About the many-world interpretation (MWI), we explain that it is neither local nor nonlocal, that it cannot explain the Born rule, that it suffers from the preferred basis problem, and that quantum suicide cannot be used to test it. About the Bohmian interpretation, we explain that it is analogous to dark matter, use it to explain that there is no big difference between nonlocal correlation and nonlocal causation, and use some condensed-matter ideas to outline how nonrelativistic Bohmian theory could be a theory of everything. We also explain how different interpretations can be used to demystify the delayed choice experiment, to resolve the problem of time in quantum gravity, and to provide alternatives to quantum nonlocality. Finally, we explain why is life compatible with the second law.

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

    Science.gov (United States)

    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

  4. Objective interpretation as conforming interpretation

    Directory of Open Access Journals (Sweden)

    Lidka Rodak

    2011-12-01

    Full Text Available The practical discourse willingly uses the formula of “objective interpretation”, with no regards to its controversial nature that has been discussed in literature.The main aim of the article is to investigate what “objective interpretation” could mean and how it could be understood in the practical discourse, focusing on the understanding offered by judicature.The thesis of the article is that objective interpretation, as identified with textualists’ position, is not possible to uphold, and should be rather linked with conforming interpretation. And what this actually implies is that it is not the virtue of certainty and predictability – which are usually associated with objectivity- but coherence that makes the foundation of applicability of objectivity in law.What could be observed from the analyses, is that both the phenomenon of conforming interpretation and objective interpretation play the role of arguments in the interpretive discourse, arguments that provide justification that interpretation is not arbitrary or subjective. With regards to the important part of the ideology of legal application which is the conviction that decisions should be taken on the basis of law in order to exclude arbitrariness, objective interpretation could be read as a question “what kind of authority “supports” certain interpretation”? that is almost never free of judicial creativity and judicial activism.One can say that, objective and conforming interpretation are just another arguments used in legal discourse.

  5. Is the Aluminum Hypothesis Dead?

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Donald W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Okuniewski, M. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sisneros, Thomas A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clausen, Bjorn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moore, G. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Balogh, L [Queen' s Univ., Kingston, ON (Canada)

    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.

  7. Interpretive Experiments

    Science.gov (United States)

    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)

  8. Performance of Simple Gas Foil Thrust Bearings in Air

    Science.gov (United States)

    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

  9. Error in interpreting field chlorophyll fluorescence measurements: heat gain from solar radiation

    International Nuclear Information System (INIS)

    Marler, T.E.; Lawton, P.D.

    1994-01-01

    Temperature and chlorophyll fluorescence characteristics were determined on leaves of various horticultural species following a dark adaptation period where dark adaptation cuvettes were shielded from or exposed to solar radiation. In one study, temperature of Swietenia mahagoni (L.) Jacq. leaflets within cuvettes increased from approximately 36C to approximately 50C during a 30-minute exposure to solar radiation. Alternatively, when the leaflets and cuvettes were shielded from solar radiation, leaflet temperature declined to 33C in 10 to 15 minutes. In a second study, 16 horticultural species exhibited a lower variable: maximum fluorescence (F v :F m ) when cuvettes were exposed to solar radiation during the 30-minute dark adaptation than when cuvettes were shielded. In a third study with S. mahagoni, the influence of self-shielding the cuvettes by wrapping them with white tape, white paper, or aluminum foil on temperature and fluorescence was compared to exposing or shielding the entire leaflet and cuvette. All of the shielding methods reduced leaflet temperature and increased the F v :F m ratio compared to leaving cuvettes exposed. These results indicate that heat stress from direct exposure to solar radiation is a potential source of error when interpreting chlorophyll fluorescence measurements on intact leaves. Methods for moderating or minimizing radiation interception during dark adaptation are recommended. (author)

  10. Interaction of relativistic H- ions with thin foils

    International Nuclear Information System (INIS)

    Mohagheghi, A.H.

    1990-09-01

    The response of relativistic H - ions to thin carbon foils was investigated for beam energies ranging from 226 MeV to 800 MeV. For the foil thicknesses we have studied, ranging from 15 to 300 μg/cm 2 , an appreciable fraction of the H - beam survives intact, some H - ions are stripped down to protons, and the remainder is distributed over the states of H 0 . This experiment is different from the low energy studies in that the projectile velocity is comparable to the speed of light, leading to an interaction time of typically less than a femtosecond. The present results challenge the theoretical understanding of the interaction mechanisms. An electron spectrometer was used to selectively field-ionize the Rydberg states, 9 < n < 17, at beam energies of 581 MeV and 800 MeV. The yield of low-lying states were measured by Doppler tuning a Nd:YAG laser to excite transitions to a Rydberg state which was then field-ionized and detected. A simple model is developed to fit the yield of each state as a function of foil thickness. The simple model is successful in predicting the general features of the yield data. However, the data are suggestive of a more complex structure in the yield curves. The yield of a given state depends strongly on the foil thickness, demonstrating that the excited states are formed during the passage of the ions through a foil. The optimum thickness to produce a given state increases with the principal quantum number of the state suggesting an excitation process which is at least pratially stepwise. The results of a Monte Carlo simulation are compared with the experimental data to estimate the distribution of the excited states coming out of a foil. The distributions of the excited states and their dependence on foil thickness are discussed

  11. Hydrogen gas generation from metal aluminum-water interaction in municipal solid waste incineration (MSWI) bottom ash.

    Science.gov (United States)

    Nithiya, Arumugam; Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki

    2018-03-01

    In the present research, municipal solid waste incineration (MSWI) bottom ash (BA) residues from three incinerators (N, K, and R) in Japan were collected for hydrogen gas generation purpose. The samples were split into four particle size fractions: (1) d≤0.6, (2) 0.6≤d≤1.0, (3) 1.0≤d≤2.0, and (4) 2.0≤d≤4.75mm for the characterization of metal aluminum, the relationship between the present metal aluminum and hydrogen gas production, and the influence of external metal aluminum on the enhancement of hydrogen gas. The batch experiments were performed for each BA fraction under agitated (200rpm) and non-agitated conditions at 40°C for 20days. The highest amount of hydrogen gas (cumulative) was collected under agitation condition that was 39.4, 10.0, and 8.4 L/kg of dry ash for N2, R2, and K2 (all fraction 2), respectively. To take the benefit of the BA high alkalinity (with initial pH over 12), 0.1 and 1g of household aluminum foil were added to the fractions 2 and 3. A Significantly larger amount of hydrogen gas was collected from each test. For 0.1g of aluminum foil, the cumulative amount of gas was in the range of 62 to 78 L/kg of dry ash and for 1g of aluminum foil the cumulative amount of hydrogen was in the range of 119-126 L/kg of dry ash. This indicated that the hydrogen gas yield was significantly a function of supplementary aluminum and the intrinsic alkaline environment of the BA residues rather than ash source or particle size. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Advances in aluminum pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Sudour, Michel; Maintier, Philippe [PPG Industries France, 3 Z.A.E. Les Dix Muids, B.P. 89, F-59583 Marly (France); Simpson, Mark [PPG Industries Inc., 1200 Piedmont Troy, Michigan 48083 (United States); Quaglia, Paolo [PPG Industries Italia, Via Garavelli 21, I-15028 Quattordio (Italy)

    2004-07-01

    As automotive manufacturers continue to look for ways to reduce vehicle weight, aluminum is finding more utility as a body panel component. The substitution of cold-rolled steel and zinc-coated substrates with aluminum has led to new challenges in vehicle pretreatment. As a result, changes to traditional pretreatment chemistries and operating practices are necessary in order to produce an acceptable coating on aluminum body panels. These changes result in increased sludging and other undesirable characteristics. In addition to the chemistry changes, there are also process-related problems to consider. Many existing automotive pretreatment lines simply were not designed to handle aluminum and its increased demands on filtration and circulation equipment. To retrofit such a system is capital intensive and in addition to requiring a significant amount of downtime, may not be totally effective. Thus, the complexities of pre-treating aluminum body panels have actually had a negative effect on efforts to introduce more aluminum into new vehicle design programs. Recent research into ways of reducing the negative effects has led to a new understanding of the nature of zinc phosphate bath -aluminum interactions. Many of the issues associated with the pretreatment of aluminum have been identified and can be mitigated with only minor changes to the zinc phosphate bath chemistry. The use of low levels of soluble Fe ions, together with free fluoride, has been shown to dramatically improve the efficiency of a zinc phosphate system processing aluminum. Appearance of zinc phosphate coatings, coating weights and sludge are all benefited by this chemistry change. (authors)

  13. Interpreting Physics

    CERN Document Server

    MacKinnon, Edward

    2012-01-01

    This book is the first to offer a systematic account of the role of language in the development and interpretation of physics. An historical-conceptual analysis of the co-evolution of mathematical and physical concepts leads to the classical/quatum interface. Bohrian orthodoxy stresses the indispensability of classical concepts and the functional role of mathematics. This book analyses ways of extending, and then going beyond this orthodoxy orthodoxy. Finally, the book analyzes how a revised interpretation of physics impacts on basic philosophical issues: conceptual revolutions, realism, and r

  14. Dosimetric response of united, commercially available CTA foils for sup 6 sup 0 Co gamma rays

    CERN Document Server

    Peimel-Stuglik, Z

    2001-01-01

    The usefulness of two kinds of untinted CTA foils: Fuji CTR-125 dosimetric foil and technical CTA-T foil, produced by 'Zaklady Chemiczne, 'Gorzow Wielkopolski' as support for light-sensitive layers of amateur photo-films, for sup 6 sup 0 Co gamma ray dosimetry was investigated. In spite of rather bad physical parameters of the technical foil (spread of foil thickness, high and different initial absorbance) the dosimetric response of both foils for sup 6 sup 0 Co gamma rays was similar. The CTA-T foil can be used for routine dosimetry providing that dosimetric signals have to be calculated exactly as recommended by the ASTM (American Society for Testing and Materials) standard, i.e. as the difference of absorbance of irradiated and (the same) non-irradiated foil. Any other approach may lead to high errors of dose evaluation. The last is true also for other CTA foils, especially after long self-life.

  15. Smooth nylon foil (SupraFOIL) orbital implants in orbital fractures: a case series of 181 patients.

    Science.gov (United States)

    Park, D J John; Garibaldi, Daniel C; Iliff, Nicholas T; Grant, Michael P; Merbs, Shannath L

    2008-01-01

    The SupraFOIL smooth nylon foil implant is a polyamide sheet available in varying thicknesses that has been used in orbital reconstruction following trauma. The authors report their experience with smooth nylon foil implants in the repair of orbital fractures. A retrospective chart review of patients having undergone repair of orbital fractures between January 1, 1995 and December 31, 2003 was conducted. The Wilcoxon test was used to compare cases with complications and those with no complications. Of 282 orbits that underwent fracture repair with alloplastic material, 87 were excluded because non-nylon foil implants were used alone or in combination with nylon foil to repair the orbital fracture. An additional 14 fractures were excluded because of insufficient clinical data or lack of follow-up, for a total of 181 orbits that underwent orbital fracture repair with only nylon foil. A transconjunctival approach was used in 98% cases, and all 181 implants were fixated with at least 1 titanium screw. Average follow-up was 362.8 days. The overall complication rate was 1.7%. One patient had an acute postoperative orbital hemorrhage (0.6% acute complication rate). Two patients had late orbital infections, 683 days and 984 days following repair (1.1% late complication rate). The authors found the smooth nylon foil implant to be safe and effective in orbital fracture repair. The lower rate of complications the authors observed compared with previously reported series may be related to implant fixation. A titanium screw secured just posterior to the orbital rim may decrease long-term complications by providing more stability than implants left without fixation.

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

    Science.gov (United States)

    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.

  17. Dynamics and locomotion of flexible foils in a frictional environment

    Science.gov (United States)

    Wang, Xiaolin; Alben, Silas

    2018-01-01

    Over the past few decades, oscillating flexible foils have been used to study the physics of organismal propulsion in different fluid environments. Here, we extend this work to a study of flexible foils in a frictional environment. When the foil is oscillated by heaving at one end but is not free to locomote, the dynamics change from periodic to non-periodic and chaotic as the heaving amplitude increases or the bending rigidity decreases. For friction coefficients lying in a certain range, the transition passes through a sequence of N-periodic and asymmetric states before reaching chaotic dynamics. Resonant peaks are damped and shifted by friction and large heaving amplitudes, leading to bistable states. When the foil is free to locomote, the horizontal motion smoothes the resonant behaviours. For moderate frictional coefficients, steady but slow locomotion is obtained. For large transverse friction and small tangential friction corresponding to wheeled snake robots, faster locomotion is obtained. Travelling wave motions arise spontaneously, and move with horizontal speeds that scale as transverse friction coefficient to the power 1/4 and input power that scales as the transverse friction coefficient to the power 5/12. These scalings are consistent with a boundary layer form of the solutions near the foil's leading edge.

  18. Effects of crystalline structure in the transmission of ions through thin foils

    International Nuclear Information System (INIS)

    Archubi, Claudio

    2005-01-01

    Two fundamental aspects of ion transmission through thin foils are analyzed in this thesis.1) Energy loss.2) Angular distribution.The subject is studied in three different approaches: Theoretically, experimentally and by numerical simulations.In the theoretical approach, the models for the calculation of the energy loss and angular distribution are discussed.They are showed to be unsatisfactory to explain the effects of crystalline structure at low energies.A model is developed to estimate the angular dispersion due to the elastic scattering between the projectile and the target electrons. Simultaneously, angular distribution and energy loss measurements have been performed bombarding polycrystalline and monocrystalline gold and polycrystalline aluminum targets with protons and helium ions with energies in the range of 4-10 keV, together with a detailed study of the foils by electron transmission microscopy techniques.The experimental results are compared with the results of a numerical simulation code, modified and extended in the scope of this thesis.The results show an important influence of crystalline structure and the different targets defects in the angular distribution.This influence is much lower in the case of the angular behaviour of the energy loss (being almost negligible in the case of protons).The most relevant characteristic of the angular behaviour of the energy loss in the case of helium ions is that it is necessary to assume in the simulation method an impact parameter dependence of the stopping coefficient to obtain an agreement between simulation and experimental results [es

  19. Corrosion Inhibitors for Aluminum.

    Science.gov (United States)

    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)

  20. Corrosion Protection of Aluminum

    Science.gov (United States)

    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.

  1. Foil Bearing Coating Behavior in CO2

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Matthew [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Kruizenga, Alan Michael [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Pasch, James Jay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fleming, Darryn [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    The Sandia S-CO2 Recompression Closed Brayton Cycle (RCBC) utilizes a series of gas foil bearings in its turbine-alternator-compressors. At high shaft rotational speed these bearings allow the shaft to ride on a cushion of air. Conversely, during startup and shutdown, the shaft rides along the foil bearing surface. Low-friction coatings are used on bearing surfaces in order to facilitate rotation during these periods. An experimental program was initiated to elucidate the behavior of coated bearing foils in the harsh environments of this system. A test configuration was developed enabling long duration exposure tests, followed by a range of analyses relevant to their performance in a bearing. This report provides a detailed overview of this work. The results contained herein provide valuable information in selecting appropriate coatings for more advanced future bearing-rig tests at the newly established test facility in Sandia-NM.

  2. Model-Based Optimization for Flapping Foil Actuation

    Science.gov (United States)

    Izraelevitz, Jacob; Triantafyllou, Michael

    2014-11-01

    Flapping foil actuation in nature, such as wings and flippers, often consist of highly complex joint kinematics which present an impossibly large parameter space for designing bioinspired mechanisms. Designers therefore often build a simplified model to limit the parameter space so an optimum motion trajectory can be experimentally found, or attempt to replicate exactly the joint geometry and kinematics of a suitable organism whose behavior is assumed to be optimal. We present a compromise: using a simple local fluids model to guide the design of optimized trajectories through a succession of experimental trials, even when the parameter space is too large to effectively search. As an example, we illustrate an optimization routine capable of designing asymmetric flapping trajectories for a large aspect-ratio pitching and heaving foil, with the added degree of freedom of allowing the foil to move parallel to flow. We then present PIV flow visualizations of the optimized trajectories.

  3. Compliant Foil Journal Bearings - Investigation of Dynamic Properties

    DEFF Research Database (Denmark)

    Larsen, Jon Steffen; Santos, Ilmar

    and dynamic coefficients, of the compliant foil bearing together with an efficient solution method, which can be easily adopted and implemented by mechanical engineers. A theoretical model of a radial compliant foil bearing that incorporates compressibility of the lubricating gas and flexibility...... a Bubnow-Galerkin approach. This constitutes the main original contribution of this work, considering the fact that the finite difference method is commonly used and thouroughly investigated in the literature. The finite element method leads to a set of non-linear equations for the static fluid film...... on the compliant foil bearings, and the understanding of their dynamic behaviour is growing. However, practical design involving these bearings are still associated with a large degree of trial and error. This study aims at establishing an accurate mathematical model, to calculate the pressure, film height...

  4. Acceleration of polyethelene foils by laser driven ablation

    International Nuclear Information System (INIS)

    Ahlstrom, H.G.; Burginyon, G.A.; Haas, R.A.

    1974-01-01

    The production of thermonuclear energy, by laser driven implosion of spherical DT shells, with achievable laser technology, requires the development of an efficient and stable implosion. Certain aspects of the acceleration of the spherical shells can be studied experimentally by irradiating thin, 5 to 25 μm, polyethelene foils. The results of foil acceleration experiments performed using a Nd:YAG-Glass laser capable of producing 150 J, 1 nsec pulses will be discussed. The dynamics of the accelerated foil, the ion blow off, high energy electron spectrum (6 to 180 keV), x-ray spectrum (1 to 150 keV) the spatial distribution of the x-ray emission, the laser beam focal spot energy distribution, the laser temporal pulse shape and spectrum for reflected and transmitted radiation have all been measured simultaneously. The results of these measurements are compared with detailed numerical simulations. (U.S.)

  5. Transmission of fast molecular ions through thin foils

    International Nuclear Information System (INIS)

    Pietsch, W.J.; Gemmell, D.S.; Cooney, P.J.; Kanter, E.P.; Kurath, D.; Ratkowski, A.J.; Vager, Z.; Zabransky, B.J.

    1979-01-01

    New results on the transmission of fast molecular ions through thin foils are presented and a mechanism for the transmission process is proposed. The main feature of the postulated mechanism is that a finite fraction of the incident molecular beam does not undergo a strong Coulomb explosion while traversing the foil. Because the emerging fragments are at large internuclear separations, there is an enhanced probability for the formation of bound, long-range, excited electronic states following electron capture at the rear surface of the target

  6. Method and apparatus for tensile testing of metal foil

    Science.gov (United States)

    Wade, O. W. (Inventor)

    1976-01-01

    A method for obtaining accurate and reproducible results in the tensile testing of metal foils in tensile testing machines is described. Before the test specimen are placed in the machine, foil side edges are worked until they are parallel and flaw free. The specimen are also aligned between and secured to grip end members. An aligning apparatus employed in the method is comprised of an alignment box with a longitudinal bottom wall and two upright side walls, first and second removable grip end members at each end of the box, and a means for securing the grip end members within the box.

  7. Interpretive Medicine

    Science.gov (United States)

    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

  8. Performance of the carbon stripping foils in the Argonne FN tandem

    International Nuclear Information System (INIS)

    Den Hartog, P.K.; Munson, F.; Heath, C.; Thomas, G.

    1980-01-01

    Carbon stripping foils produced by the glow discharge cracking of ethylene were produced and the foils were tested in the Argonne FN tandem accelerator. The results are presented and the characteristics of stripping media are discussed

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

    Science.gov (United States)

    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.

  10. A new modal-based approach for modelling the bump foil structure in the simultaneous solution of foil-air bearing rotor dynamic problems

    Science.gov (United States)

    Bin Hassan, M. F.; Bonello, P.

    2017-05-01

    Recently-proposed techniques for the simultaneous solution of foil-air bearing (FAB) rotor dynamic problems have been limited to a simple bump foil model in which the individual bumps were modelled as independent spring-damper (ISD) subsystems. The present paper addresses this limitation by introducing a modal model of the bump foil structure into the simultaneous solution scheme. The dynamics of the corrugated bump foil structure are first studied using the finite element (FE) technique. This study is experimentally validated using a purpose-made corrugated foil structure. Based on the findings of this study, it is proposed that the dynamics of the full foil structure, including bump interaction and foil inertia, can be represented by a modal model comprising a limited number of modes. This full foil structure modal model (FFSMM) is then adapted into the rotordynamic FAB problem solution scheme, instead of the ISD model. Preliminary results using the FFSMM under static and unbalance excitation conditions are proven to be reliable by comparison against the corresponding ISD foil model results and by cross-correlating different methods for computing the deflection of the full foil structure. The rotor-bearing model is also validated against experimental and theoretical results in the literature.

  11. Objective interpretation as conforming interpretation

    OpenAIRE

    Lidka Rodak

    2011-01-01

    The practical discourse willingly uses the formula of “objective interpretation”, with no regards to its controversial nature that has been discussed in literature.The main aim of the article is to investigate what “objective interpretation” could mean and how it could be understood in the practical discourse, focusing on the understanding offered by judicature.The thesis of the article is that objective interpretation, as identified with textualists’ position, is not possible to uphold, and ...

  12. Aluminum industry options paper

    International Nuclear Information System (INIS)

    1999-10-01

    In 1990, Canada's producers of aluminum (third largest in the world) emitted 10 million tonnes of carbon dioxide and equivalent, corresponding to 6.4 tonnes of greenhouse gas intensity per tonne of aluminum. In 2000, the projection is that on a business-as-usual (BAU) basis Canadian producers now producing 60 per cent more aluminum than in 1990, will emit 10.7 million tonnes of carbon dioxide and equivalent, corresponding to a GHG intensity of 4.2 tonnes per tonne of aluminum. This improvement is due to production being based largely on hydro-electricity, and partly because in general, Canadian plants are modern, with technology that is relatively GHG-friendly. The Aluminum Association of Canada estimates that based on anticipated production, and under a BAU scenario, GHG emissions from aluminum production will rise by 18 per cent by 2010 and by 30 per cent by 2020. GHG emissions could be reduced below the BAU forecast first, by new control and monitoring systems at some operations at a cost of $4.5 to 7.5 million per smelter. These systems could reduce carbon dioxide equivalent emissions by 0.8 million tonnes per year. A second alternative would require installation of breaker feeders which would further reduce perfluorocarbon (PFC) emissions by 0.9 million tonnes of carbon dioxide equivalent. Cost of the breakers feeders would be in the order of $200 million per smelter. The third option calls for the the shutting down of some of the smelters with older technology by 2015. In this scenario GHG emissions would be reduced by 2010 by 0.8 million tonnes per year of carbon dioxide equivalent. However, the cost in this case would be about $1.36 billion. The industry would support measures that would encourage the first two sets of actions, which would produce GHG emissions from aluminum production in Canada of about 10.2 million tonnes per year of carbon dioxide equivalent, or about two per cent above 1990 levels with double the aluminum production of 1990. Credit for

  13. Dose reader of dosimetric foil; Czytnik dawki folii dozymetrycznej

    Energy Technology Data Exchange (ETDEWEB)

    Machaj, B.; Strzalkowski, J.; Smolko, K.

    1997-12-31

    Read out the absorbance of a dosimetric foil is accomplished by two beam spectrophotometer. Such a solution makes possible the compensation of light source instabilities and ensures higher stability of the dose reader. The error of absorbance measurement caused by the instabilities does not exceed 0.0004 A. (author). 3 refs, 3 figs.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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.

  17. The Visualization of Infrared Radiation Using Thermal Sensitive Foils

    Science.gov (United States)

    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…

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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

  19. Factors affecting use of fission foils as dosimetry sensors

    International Nuclear Information System (INIS)

    Griffin, P.J.; Vehar, D.W.; Kelly, J.G.; Holm, C.V.

    1996-01-01

    Fission foils are commonly used as dosimetry sensors. They play a very important role in neutron spectrum determinations. This paper provides a combination of experimental measurements and calculations to quantify the importance and synergy of several factors that affect the fission response of a dosimeter. Only when these effects are properly treated can fission dosimeters be used with sufficient fidelity

  20. Validation of calculated self-shielding factors for Rh foils

    Science.gov (United States)

    Jaćimović, R.; Trkov, A.; Žerovnik, G.; Snoj, L.; Schillebeeckx, P.

    2010-10-01

    Rhodium foils of about 5 mm diameter were obtained from IRMM. One foil had thickness of 0.006 mm and three were 0.112 mm thick. They were irradiated in the pneumatic transfer system and in the carousel facility of the TRIGA reactor at the Jožef Stefan Institute. The foils were irradiated bare and enclosed in small cadmium boxes (about 2 g weight) of 1 mm thickness to minimise the perturbation of the local neutron flux. They were co-irradiated with 5 mm diameter and 0.2 mm thick Al-Au (0.1%) alloy monitor foils. The resonance self-shielding corrections for the 0.006 and 0.112 mm thick samples were calculated by the Monte Carlo simulation and amount to about 10% and 60%, respectively. The consistency of measurements confirmed the validity of self-shielding factors. Trial estimates of Q0 and k0 factors for the 555.8 keV gamma line of 104Rh were made and amount to 6.65±0.18 and (6.61±0.12)×10 -2, respectively.

  1. Dynamic environmental control mechanisms for pneumatic foil constructions

    Science.gov (United States)

    Flor, Jan-Frederik; Wu, Yupeng; Beccarelli, Paolo; Chilton, John

    2017-11-01

    Membrane and foil structures have become over the last decades an attractive alternative to conventional materials and building systems with increasing implementation in different typologies and scale. The development of transparent, light, flexible and resistant materials like Ethylene Tetrafluoroethylene (ETFE) has triggered a rethinking of the building envelope in the building industry towards lightweight systems. ETFE foil cushions have proven to fulfil the design requirements in terms of structural efficiency and aesthetic values. But the strategies to satisfy increasing demands of energy efficiency and comfort conditions are still under development. The prediction and manipulation of the thermo-optical behaviour of ETFE foil cushion structures currently remain as one of the main challenges for designers and manufacturers. This paper reviews ongoing research regarding the control of the thermo-optical performance of ETFE cushion structures and highlights challenges and possible improvements. An overview of different dynamic and responsive environmental control mechanisms for multilayer foil constructions is provided and the state of the art in building application outlined by the discussion of case studies.

  2. Method and apparatus for coating thin foil with a boron coating

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, Jeffrey L.

    2018-01-16

    An apparatus and a process is disclosed for applying a boron coating to a thin foil. Preferably, the process is a continuous, in-line process for applying a coating to a thin foil comprising wrapping the foil around a rotating and translating mandrel, cleaning the foil with glow discharge in an etching chamber as the mandrel with the foil moves through the chamber, sputtering the foil with boron carbide in a sputtering chamber as the mandrel moves through the sputtering chamber, and unwinding the foil off the mandrel after it has been coated. The apparatus for applying a coating to a thin foil comprises an elongated mandrel. Foil preferably passes from a reel to the mandrel by passing through a seal near the initial portion of an etching chamber. The mandrel has a translation drive system for moving the mandrel forward and a rotational drive system for rotating mandrel as it moves forward. The etching chamber utilizes glow discharge on a surface of the foil as the mandrel moves through said etching chamber. A sputtering chamber, downstream of the etching chamber, applies a thin layer comprising boron onto the surface of the foil as said mandrel moves through said sputtering chamber. Preferably, the coated foil passes from the mandrel to a second reel by passing through a seal near the terminal portion of the sputtering chamber.

  3. Low-energy electron beams through ultra-thin foils, applications for electron microscopy

    NARCIS (Netherlands)

    Van Aken, R.H.

    2005-01-01

    This thesis has discussed two electron microscopy applications that make use of ultra-thin foils: the tunnel junction emitter and the low-energy foil corrector. Both applications have in common that the electron beam is sent through the thin foil at low energy. Part of the electrons will scatter in

  4. Wake visualization of a heaving and pitching foil in a soap film

    NARCIS (Netherlands)

    Muijres, F.T.; Lentink, D.

    2007-01-01

    Many fish depend primarily on their tail beat for propulsion. Such a tail is commonly modeled as a two-dimensional flapping foil. Here we demonstrate a novel experimental setup of such a foil that heaves and pitches in a soap film. The vortical flow field generated by the foil correlates with

  5. Aluminum for plasmonics.

    Science.gov (United States)

    Knight, Mark W; King, Nicholas S; Liu, Lifei; Everitt, Henry O; Nordlander, Peter; Halas, Naomi J

    2014-01-28

    Unlike silver and gold, aluminum has material properties that enable strong plasmon resonances spanning much of the visible region of the spectrum and into the ultraviolet. This extended response, combined with its natural abundance, low cost, and amenability to manufacturing processes, makes aluminum a highly promising material for commercial applications. Fabricating Al-based nanostructures whose optical properties correspond with theoretical predictions, however, can be a challenge. In this work, the Al plasmon resonance is observed to be remarkably sensitive to the presence of oxide within the metal. For Al nanodisks, we observe that the energy of the plasmon resonance is determined by, and serves as an optical reporter of, the percentage of oxide present within the Al. This understanding paves the way toward the use of aluminum as a low-cost plasmonic material with properties and potential applications similar to those of the coinage metals.

  6. Aluminum Hydroxide and Magnesium Hydroxide

    Science.gov (United States)

    Aluminum Hydroxide, Magnesium Hydroxide are antacids used together to relieve heartburn, acid indigestion, and upset stomach. They ... They combine with stomach acid and neutralize it. Aluminum Hydroxide, Magnesium Hydroxide are available without a prescription. ...

  7. Regeneration of aluminum hydride

    Science.gov (United States)

    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.

  8. Regeneration of aluminum hydride

    Science.gov (United States)

    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.

  9. Mammographic interpretation

    International Nuclear Information System (INIS)

    Tabor, L.

    1987-01-01

    For mammography to be an effective diagnostic method, it must be performed to a very high standard of quality. Otherwise many lesions, in particular cancer in its early stages, will simply not be detectable on the films, regardless of the skill of the mammographer. Mammographic interpretation consists of two basic steps: perception and analysis. The process of mammographic interpretation begins with perception of the lesion on the mammogram. Perception is influenced by several factors. One of the most important is the parenchymal pattern of the breast tissue, detection of pathologic lesions being easier with fatty involution. The mammographer should use a method for the systematic viewing of the mammograms that will ensure that all parts of each mammogram are carefully searched for the presence of lesions. The method of analysis proceeds according to the type of lesion. The contour analysis of primary importance in the evaluation of circumscribed tumors. After having analyzed the contour and density of a lesion and considered its size, the mammographer should be fairly certain whether the circumscribed tumor is benign or malignant. Fine-needle puncture and/or US may assist the mammographer in making this decision. Painstaking analysis is required because many circumscribed tumors do not need to be biopsied. The perception of circumscribed tumors seldom causes problems, but their analysis needs careful attention. On the other hand, the major challenge with star-shaped lesions is perception. They may be difficult to discover when small. Although the final diagnosis of a stellate lesion can be made only with the help of histologic examination, the preoperative mammorgraphic differential diagnosis can be highly accurate. The differential diagnostic problem is between malignant tumors (scirrhous carcinoma), on the one hand, and traumatic fat necrosis as well as radial scars on the other hand

  10. Aluminum plasmonic nanoshielding in ultraviolet inactivation of bacteria.

    Science.gov (United States)

    Kunz, Jeremy N; Voronine, Dmitri V; Lu, Weigang; Liege, Zachary; Lee, Ho Wai Howard; Zhang, Zhenrong; Scully, Marlan O

    2017-08-22

    Ultraviolet (UV) irradiation is an effective bacterial inactivation technique with broad applications in environmental disinfection. However, biomedical applications are limited due to the low selectivity, undesired inactivation of beneficial bacteria and damage of healthy tissue. New approaches are needed for the protection of biological cells from UV radiation for the development of controlled treatment and improved biosensors. Aluminum plasmonics offers attractive opportunities for the control of light-matter interactions in the UV range, which have not yet been explored in microbiology. Here, we investigate the effects of aluminum nanoparticles (Al NPs) prepared by sonication of aluminum foil on the UVC inactivation of E. coli bacteria and demonstrate a new radiation protection mechanism via plasmonic nanoshielding. We observe direct interaction of the bacterial cells with Al NPs and elucidate the nanoshielding mechanism via UV plasmonic resonance and nanotailing effects. Concentration and wavelength dependence studies reveal the role and range of control parameters for regulating the radiation dosage to achieve effective UVC protection. Our results provide a step towards developing improved radiation-based bacterial treatments.

  11. Plastic deformation mechanism of polycrystalline copper foil shocked with femtosecond laser

    International Nuclear Information System (INIS)

    Ye, Y.X.; Feng, Y.Y.; Lian, Z.C.; Hua, Y.Q.

    2014-01-01

    Plastic deformation mechanism of polycrystalline copper foil shocked with femtosecond (fs) laser has been characterized through optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Experiments of ns laser shocking copper (Cu) and fs laser shocking aluminum (Al) were also conducted for comparison. Dislocations arranged in multiple forms, profuse twins and stacking faults (SFs) coexist in the fs laser shocked copper. At small strain condition, dislocation slip is the dominant deformation mode and small amount of SFs act as complementary mechanism. With strain increasing, profuse twins and SFs form to accommodate the plastic deformation. Furthermore, new formed SFs incline to locate around the old ones because the dislocation densities there are more higher. So there is a high probability for new SFs overlapping on old ones to form twins, or connecting old ones to lengthen them, which eventually produce the phenomena that twins connect with each other or twins connect with SFs. Strain greatly influences the dislocation density. Twins and SFs are more dependent on strain rate and shock pressure. Medium stacking fault energy (SFE) of copper helps to extend partial dislocations and provides sources for forming SFs and twins.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

    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 μm 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.

  13. Phases in lanthanum-nickel-aluminum alloys

    International Nuclear Information System (INIS)

    Mosley, W.C.

    1992-01-01

    Lanthanum-nickel-aluminum (LANA) alloys will be used to pump, store and separate hydrogen isotopes in the Replacement Tritium Facility (RTF). The aluminum content (y) of the primary LaNi 5 -phase is controlled to produce the desired pressure-temperature behavior for adsorption and desorption of hydrogen. However, secondary phases cause decreased capacity and some may cause undesirable retention of tritium. Twenty-three alloys purchased from Ergenics, Inc. for development of RTF processes have been characterized by scanning electron microscopy (SEM) and by electron microprobe analysis (EMPA) to determine the distributions and compositions of constituent phases. This memorandum reports the results of these characterization studies. Knowledge of the structural characteristics of these alloys is a useful first step in selecting materials for specific process development tests and in interpreting results of those tests. Once this information is coupled with data on hydrogen plateau pressures, retention and capacity, secondary phase limits for RTF alloys can be specified

  14. An Interpreter's Interpretation: Sign Language Interpreters' View of Musculoskeletal Disorders

    National Research Council Canada - National Science Library

    Johnson, William L

    2003-01-01

    Sign language interpreters are at increased risk for musculoskeletal disorders. This study used content analysis to obtain detailed information about these disorders from the interpreters' point of view...

  15. Numerical studies on the interaction between two parallel D-cylinder and oscillated foil

    Science.gov (United States)

    Chao, Li-Ming; Zhang, Dong; Cao, Yong-Hui; Pan, Guang

    2018-02-01

    To understand the interaction between the oscillated body and oncoming vortex, some numerical studies have been conducted on a system including two parallel D-cylinder and one oscillated foil in this paper. It is found that the distance between parallel D-cylinder and oscillated foil would play a key role in affecting the change regulation of thrust generation of oscillated foil, and the kinematics of oscillated foil would determine the value of propulsive thrust, the gap between two parallel D-cylinder would only affect the hydrodynamic performance of oscillated foil at intermediate conditions.

  16. Studies of PMMA sintering foils with and without coating by magnetron sputtering Pd

    Science.gov (United States)

    Cutroneo, M.; Mackova, A.; Torrisi, L.; Vad, K.; Csik, A.; Ando', L.; Svecova, B.

    2017-09-01

    Polymethylmethacrylate thin foils were prepared by using physical and chemical processes aimed at changing certain properties. The density and the optical properties were changed obtaining clear and opaque foils. DC magnetron sputtering method was used to cover the foils with thin metallic palladium layers. The high optical absorbent foils were obtained producing microstructured PMMA microbeads with and without thin metallic coatings. Rutherford Backscattering Spectroscopy, optical investigation and microscopy were employed to characterize the prepared foils useful in the field study of laser-matter interaction.

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

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J. S.; Keiter, P. A.; Klein, S. R.; Drake, R. P.; Shvarts, D. [University of Michigan, 2455 Hayward St., Ann Arbor, Michigan 48109 (United States); Frank, Y.; Raicher, E.; Fraenkel, M. [Soreq Nuclear Research Center, Yavne (Israel)

    2016-11-15

    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.

  18. Aluminum Sulfate 18 Hydrate

    Science.gov (United States)

    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.

  19. Applied Electrochemistry of Aluminum

    DEFF Research Database (Denmark)

    Li, Qingfeng; Qiu, Zhuxian

    Electrochemistry of aluminum is of special importance from both theoretical and technological point of view. It covers a wide range of electrolyte systems from molten fluoride melts at around 1000oC to room temperature molten salts, from aqueous to various organic media and from liquid to solid...

  20. Invisible Display in Aluminum

    DEFF Research Database (Denmark)

    Prichystal, Jan Phuklin; Hansen, Hans Nørgaard; Bladt, Henrik Henriksen

    2005-01-01

    for an integrated display in a metal surface is often ruled by design and functionality of a product. The integration of displays in metal surfaces requires metal removal in order to clear the area of the display to some extent. The idea behind an invisible display in Aluminum concerns the processing of a metal...

  1. Aluminum for Plasmonics

    Science.gov (United States)

    2014-01-01

    mini - mize the deleterious effects of the bulk metal oxide. Conversely, the optical scattering spectrum of an Al nanodisk can serve as a reporter of Al...Nanoparticles. J. Phys. Chem. C 2008, 112, 13958–13963. 22. Chowdhury, M. H.; Ray, K.; Gray, S. K.; Pond , J.; Lakowicz, J. R. Aluminum Nanoparticles as

  2. Aluminum battery alloys

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  5. Borated aluminum alloy manufacturing technology

    International Nuclear Information System (INIS)

    Shimojo, Jun; Taniuchi, Hiroaki; Kajihara, Katsura; Aruga, Yasuhiro

    2003-01-01

    Borated aluminum alloy is used as the basket material of cask because of its light weight, thermal conductivity and superior neutron absorbing abilities. Kobe Steel has developed a unique manufacturing process for borated aluminum alloy using a vacuum induction melting method. In this process, aluminum alloy is melted and agitated at higher temperatures than common aluminum alloy fabrication methods. It is then cast into a mold in a vacuum atmosphere. The result is a high quality aluminum alloy which has a uniform boron distribution and no impurities. (author)

  6. 〈情報学科〉均衡型(C_9, C_14)-Foil デザイン

    OpenAIRE

    潮, 和彦

    2012-01-01

    In graph theory, the decomposition problem of graphs is a very important topic. Various type of decompositions of many graphs can be seen in the literature of graph theory. This paper gives balanced (C_9, C_14)-foil designs, balanced C_23-foil designs, balanced C_46-foil designs, balanced C_69-foil designs, balanced C_92-foil designs, balanced C_115-foil designs, balanced C_138-foil designs, balanced C_161-foil designs,balanced C_184-foil designs,balanced C207-foil designs, balanced C_230-fo...

  7. Thrombogenicity tests on ar-irradiated polycarbonate foils

    International Nuclear Information System (INIS)

    Trindade, Gustavo F.; Rizzutto, Marcia A.; Silva, Tiago F.; Moro, Marcos V.; Added, Nemitala; Tabacniks, Manfredo H.; Cunha, Tatiana F.; Higa, Olga Z.

    2013-01-01

    Understanding polymer surface properties is extremely important for the most wide range of their applications, from basic coating to the most complex composites and biomaterials. Low energy ion beam irradiation of polymer can improve such surface properties. By modifying its surface biocompatibility, polymers are excellent candidates for biomaterials, due to its malleability and low weight, when compared to metals. In this work, we irradiated 30-μm Bisphenol-A Polycarbonate foils with 23-keV Argon ion beam at six different doses. Aluminium foils were simultaneously irradiated in order to measure the doses by Rutherford Backscattering Spectroscopy. The surface modifications after the argon ion beam irradiation were analyzed by water contact angle measurements and atomic force microscopy. Platelet adhesion tests were used in order to investigate thrombogenicity, showing a growing tendency with the irradiated Argon dose. (author)

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

    Science.gov (United States)

    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.

  9. Microcutting and forming of thin aluminium foils for MEMS

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Mortensen, Dennis; Rombach, Pirmin

    2011-01-01

    This paper presents a simple procedure for simultaneous cutting and forming of thin Al foils for use in MEMS components. The procedure makes use of scaled down macroscopic sheet forming and cutting techniques by using a hydraulic press, a soft counterpart, and a microfabricated stamp tool....... The relation between applied pressure and forming and cutting features has been characterized for a specific set of stamp geometries and boundary conditions. The results show that 10 μm forming features can be transferred to 4 m thick Al foils, which simultaneously can be cut into products by 25 μm wide cut...... lines. Using the procedure presented in this paper scaled to full 4-8 in. silicon wafer stamp tools, a fast and adequate method for high volume production of MEMS components is obtained. © 2011 American Society of Mechanical Engineers....

  10. Convergent beam thickness determination of thin foil zirconium specimens

    International Nuclear Information System (INIS)

    Cann, C.D.

    1978-07-01

    The use of convergent beam patterns to determine the thickness of zirconium foils observed in the electron microscope has been investigated both theoretically and experimentally. On the basis of many-beam dynamical theory calculations, the [1012], [1013], and [1120] reflections at an accelerating voltage of 100 kV and the [1013], [1120], and [1122] reflections at 200 kV were found most suitable for convergent beam thickness determinations. Experimental convergent beam patterns were obtained in the JEOL-200B electron microscope under two different sets of conditions based on the size of the pattern desired. Computer assisted analysis of the patterns obtained gave foil thicknesses in good agreement with those determined from thickness extinction contours. (author)

  11. Tilted Foils Nuclear Spin Polarization at REX-ISOLDE

    CERN Document Server

    Törnqvist, Hans Toshihide

    2013-08-08

    This thesis will explain and summarize my work and involvement in experiments aimed at producing nuclear spin polarization of post-accelerated beams of ions with the tilted-foils technique at the REX-ISOLDE linear accelerator at CERN. Polarizing the nuclear spin of radioactive beams in particular may provide access to observables which may be difficult to obtain otherwise. Currently, the techniques commonly employed for nuclear spin polarization are restricted to specific nuclides and experimental measurement techniques. Tilted foils polarization may provide a new tool to extend the range of nuclides that can be polarized and the types of experiments that can be performed. The experiments rely not only on the production but also on the method to measure the degree of attained polarization. Two methods will be treated, based on particle scattering in Coulomb excitation that may be utilized for stable beams, and the $\\beta$-NMR that requires $\\beta$-decaying nuclei. The experimental setups and measurements will...

  12. Thrombogenicity tests on ar-irradiated polycarbonate foils

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, Gustavo F.; Rizzutto, Marcia A.; Silva, Tiago F.; Moro, Marcos V.; Added, Nemitala; Tabacniks, Manfredo H., E-mail: g.ferraz@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. de Fisica; Delgado, Adriana O. [Universidade Federal de Sao Carlos (UFSCAR), Sorocaba, SP (Brazil); Cunha, Tatiana F. [Biosintesis P and D do Brasil, Sao Paulo, SP (Brazil); Higa, Olga Z. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia

    2013-07-01

    Understanding polymer surface properties is extremely important for the most wide range of their applications, from basic coating to the most complex composites and biomaterials. Low energy ion beam irradiation of polymer can improve such surface properties. By modifying its surface biocompatibility, polymers are excellent candidates for biomaterials, due to its malleability and low weight, when compared to metals. In this work, we irradiated 30-μm Bisphenol-A Polycarbonate foils with 23-keV Argon ion beam at six different doses. Aluminium foils were simultaneously irradiated in order to measure the doses by Rutherford Backscattering Spectroscopy. The surface modifications after the argon ion beam irradiation were analyzed by water contact angle measurements and atomic force microscopy. Platelet adhesion tests were used in order to investigate thrombogenicity, showing a growing tendency with the irradiated Argon dose. (author)

  13. A new method for alkaline dissolution of uranium metal foil

    International Nuclear Information System (INIS)

    Mondino, A.V.; Wilkinson, M.V.; Manzini, A.C.

    2001-01-01

    In order to develop a production process of 99 Mo by fission of low-enriched uranium, the first purification step, which consists of dissolution of a uranium metal foil target, was studied. It was found that alkaline NaClO gave good results, reaching the dissolution of up to 300 μm of uranium foil. The different conditions for the dissolution were studied and the optimum ones were found. The influence of NaClO and NaOH concentration, temperature, dissolving solution volume per unit of surface and dissolution time were investigated. During this step, a gas identified as H 2 , was generated, and a precipitate characterized as Na 2 U 2 O 7 was observed. A stoichiometric reaction for this uranium dissolution is proposed. (author)

  14. Interpretation training influences memory for prior interpretations

    NARCIS (Netherlands)

    Salemink, E.; Hertel, P.; Mackintosh, B.

    2010-01-01

    Anxiety is associated with memory biases when the initial interpretation of the event is taken into account. This experiment examined whether modification of interpretive bias retroactively affects memory for prior events and their initial interpretation. Before training, participants imagined

  15. Note: Manganin foil sensor for small uniaxial stress

    Science.gov (United States)

    Frampton, M. K.; McLaughlin, N.; Jin, Hu; Zieve, R. J.

    2017-04-01

    We describe a simple manganin foil resistance manometer for uniaxial stress measurements. The manometer functions at low pressures and over a range of temperatures. In this design, no temperature seasoning is necessary although the manometer must be prestressed to the upper end of the desired pressure range. The prestress pressure cannot be increased arbitrarily; irreversibility arising from shear stress limits its range. Attempting larger pressures yields irreproducible resistance measurements.

  16. Dynamic nuclear polarization in thin polymer foils and tubes

    Science.gov (United States)

    van den Brandt, B.; Bunyatova, E. I.; Hautle, P.; Konter, J. A.; Mango, S.

    1995-02-01

    First results of DNP at 2.5 T and below 0.3 K in thin polymer foils and tubes with the chemical composition (CX 2) n, [ X = 1H, 2D, 19F ], doped with TEMPO, are presented. Appreciable polarization of protons, deuterons, and 19F-nuclei were obtained. The samples can be handled at room temperature for several hours, and therefore they are suitable for new applications.

  17. Dynamic nuclear polarization in thin polymer foils and tubes

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, B. van den [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Bunyatova, E.I. [Joint Inst. for Nuclear Research, Dubna (Russian Federation); Hautle, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Konter, J.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Mango, S. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1995-03-01

    First results of DNP at 2.5 T and below 0.3 K in thin polymer foils and tubes with the chemical composition (CX{sub 2}){sub n}, [X={sup 1}H, {sup 2}D, {sup 19}F], doped with TEMPO, are presented. Appreciable polarizations of protons, deuterons, and {sup 19}F-nuclei were obtained. The samples can be handled at room temperature for several hours, and therefore they are suitable for new applications. ((orig.))

  18. Interaction of positron beams with thin silver foils and surfaces

    International Nuclear Information System (INIS)

    Rysholt Poulsen, M.

    1994-01-01

    Experimental investigations of positron interactions with solid silver and the necessary platform to analyse the data have been presented. The main objective was to study Ps formation at a Ag(100) surface. The different ingredients of the scenario, including thermalization and diffusion of positrons and emission of Ps, were analysed and quantified in whatever way appropriate. The scattering and possible thermalization were described. The parametrization of Monte-Carlo simulated implantation profiles for semi-infinite materials were presented and the applicability of such profiles to thin foils assessed. The latter was done in conjunction with an analysis of experimental data on thermalization and diffusion in 1900 Aa Ag(100) foils. The necessity for MC simulated rather than parametrized implantation profiles was argued. The velocity of thermally desorbed Ps from a Ag(100) surface at ∼800 K appeared to obey and one-dimensional Maxwell Boltzmann distribution multiplied by a velocity dependent factor. More experimental investigations are needed before firm conclusions can be made on the nature of the emission process. The velocity distribution, though, was found to be near-thermal and indicative of the sample temperature. It has been shown that positrons can be converted into Ps atoms in the transmission geometry of a thin 1900 Aa Ag(100) foil with a high efficiency. Furthermore, 61% of the emitted Ps will have a mean velocity of v z =1.2x10 5 m/sec and 39% will have a maximum kinetic energy of 1.5 eV (v z =5.1x10 5 m/sec) at a foil temperature of 800 K, all velocities that are suitable for producing a 'dense' Ps gas target. (EG) 12 refs

  19. Synthetic Graphene Grown by Chemical Vapor Deposition on Copper Foils

    Science.gov (United States)

    2013-04-11

    review the synthesis and properties of CVD -grown graphene , demonstrated using examples pimarily from our work in re- cent years. Particularly, we will...promise for many applica- tions.60 Compared to other large-scale graphene synthesis methods, CVD -grown graphene on copper foil substrates has been shown to...methods. Despite the fact that CVD - grown graphene films may be less perfect (the presence of domain boundaries, defects, wrinkles, impurities and

  20. A Manganin Foil Sensor for Small Uniaxial Stress

    OpenAIRE

    Frampton, M. K.; McLaughlin, N.; Jin, Hu; Zieve, R. J.

    2017-01-01

    We describe a simple manganin foil resistance manometer for uniaxial stress measurements. The manometer functions at low pressures and over a range of temperatures. In this design no temperature seasoning is necessary, although the manometer must be prestressed to the upper end of the desired pressure range. The prestress pressure cannot be increased arbitrarily; irreversibility arising from shear stress limits its range. Attempting larger pressures yields irreproducible resistance measurements.

  1. Ablative acceleration of thin foil targets by intense proton beams

    International Nuclear Information System (INIS)

    Miyamoto, S.; Ozaki, T.; Imasaki, K.; Higaki, S.; Nakai, S.

    1981-01-01

    A focused proton beam of up to 2 x 10 10 w/cm 2 was obtained using pinch-reflex ion diode connected to Reiden IV generator. Experiments of beam target interaction have been done using thin foil targets. In this power range the interaction was explained classically. The experimental dependence of ablation pressure on proton beam intensity was obtained as P sub(a) = 3 x 10 -3 I sup(0.7) bar (I in w/cm 2 ). (author)

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

    Science.gov (United States)

    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.

  3. Design of organic complementary circuits and systems on foil

    CERN Document Server

    Abdinia, Sahel; Cantatore, Eugenio

    2015-01-01

    This book describes new approaches to fabricate complementary organic electronics, and focuses on the design of circuits and practical systems created using these manufacturing approaches. The authors describe two state-of-the-art, complementary organic technologies, characteristics and modeling of their transistors and their capability to implement circuits and systems on foil. Readers will benefit from the valuable overview of the challenges and opportunities that these extremely innovative technologies provide. ·         Demonstrates first circuits implemented using specific complementary organic technologies, including first printed analog to digital converter, first dynamic logic on foil and largest complementary organic circuit ·         Includes step-by-step design from single transistor level to complete systems on foil ·         Provides a platform for comparing state-of-the-art complementary organic technologies and for comparing these with other similar technologies, spec...

  4. Small incision removal of nylon foil orbital implants.

    Science.gov (United States)

    Liu, Catherine Y; Vemuri, Swapna; Tao, Jeremiah P

    2015-01-01

    To describe a small incision technique for the removal of a nylon foil orbital wall implant. The authors retrospectively reviewed the charts of 9 patients who underwent a minimally invasive anterior orbitotomy for nylon foil explantation. Indications for removal and surgical technique, including size of orbitotomy incision and extent of orbital dissection, were recorded. Motility, globe position, strabismus pre- and post procedure, and complications were also assessed. Photographs, videos, and postoperative imaging were included, when available. The indications for removal were adjacent sinusitis (4 cases), undesirable implant position (3), orbital abscess (1), and adjacent orbital emphysema (1). The removal technique was associated with no changes in motility, globe position, or strabismus postprocedure. The average incision size was 1.1 cm, and the procedure was rapid, usually seconds once the anterior aspect of the implant was exposed and grasped with a hemostat. The dissection in all cases was to the anterior aspect of the implant without a need for deep orbital manipulation. The authors demonstrate through video that the implant folds to exit through a small incision. No adverse events were noted. Nasal endoscopy and radiography demonstrated a fibrous capsule that maintained orbital structure and support. Thin nylon foil implant can be explanted safely and efficiently through a very small incision. The orbit maintains structure and configuration postexplantation in this series.

  5. Simulation of thin aluminium-foil in the packaging industry

    Science.gov (United States)

    Eskil, Andreasson; Lindström, Tommy; Käck, Britta; Malmberg, Christoffer; Asp, Ann-Magret

    2017-10-01

    This work present an approach of how to account for the anisotropic mechanical material behaviour in the simulation models of the thin aluminium foil layer (≈10 µm) used in the Packaging Industry. Furthermore, the experimental results from uniaxial tensile tests are parameterised into an analytical expression and the slope of the hardening subsequently extended way beyond the experimental data points. This in order to accommodate the locally high stresses present in the experiments at the neck formation. An analytical expression, denominated Ramberg-Osgood, is used to describe the non-linear mechanical behaviour. Moreover it is possible with a direct method to translate the experimental uniaxial tensile test results into useful numerical material model parameters in Abaqus™. In addition to this the extended material behaviour including the plastic flow i.e. hardening, valid after onset of localisation, the described procedure can also capture the microscopic events, i.e. geometrical thinning, ongoing in the deformation of the aluminium foil. This method has earlier successfully been applied by Petri Mäkelä for paperboard material [1]. The engineering sound and parameterised description of the mechanical material behaviour facilitates an efficient categorisation of different aluminium foil alloys and aid the identification of the correct anisotropic (RD/TD/45°) mechanical material behaviour derived from the physical testing.

  6. Propulsive performance of pitching foils with variable chordwise flexibility

    Science.gov (United States)

    Zeyghami, Samane; Moored, Keith; Lehigh University Team

    2017-11-01

    Many swimming and flying animals propel themselves efficiently through water by oscillating flexible fins. These fins are not homogeneously flexible, but instead their flexural stiffness varies along their chord and span. Here we seek to evaluate the effect stiffness profile on the propulsive performance of pitching foils. Stiffness profile characterizes the variation in the local fin stiffness along the chord. To this aim, we developed a low order model of a functionally-graded material where the chordwise flexibility is modeled by two torsional springs along the chordline and the stiffness and location of the springs can be varied arbitrarily. The torsional spring structural model is then strongly coupled to a boundary element fluid model to simulate the fluid-structure interactions. Keeping the leading edge kinematics unchanged, we alter the stiffness profile of the foil and allow it to swim freely in response to the resulting hydrodynamic forces. We then detail the dependency of the hydrodynamic performance and the wake structure to the variations in the local structural properties of the foil.

  7. Abundance of interstellar aluminum

    Science.gov (United States)

    Barker, E. S.; Lugger, P. M.; Weiler, E. J.; York, D. G.

    1984-01-01

    New observations of Al II 1670 A, the only line of the dominant ionization stage of interstellar aluminum detected to date, are presented. Observations of ionized silicon are used to define an empirical curve of growth from which aluminum depletions can be derived. The depletion ranges from a factor of 10 in alpha Vir, with E(B-V) of about 0.04, to a factor of 1000 in omicron Per. The depletion is similar to that of iron, but a factor of 2-10 lower than that for silicon in the same stars. The observations of near-UV lines using the Copernicus V1 tubes with removal of a high cosmic-ray-induced fluorescent background are described.

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

    Science.gov (United States)

    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

  9. Behavior of aluminum in aluminum welders and manufacturers of aluminum sulfate--impact on biological monitoring.

    Science.gov (United States)

    Riihimäki, Vesa; Valkonen, Sinikka; Engström, Bernt; Tossavainen, Antti; Mutanen, Pertti; Aitio, Antero

    2008-12-01

    The suitability of determining aluminum in serum or urine as a form of biological monitoring was critically assessed. Airborne and internal aluminum exposure was assessed for 12 aluminum welders in a shipyard and 5 manufacturers of aluminum sulfate. Particles were characterized with X-ray diffraction and scanning electron microscopy. Aluminum in air and biological samples was analyzed using electrothermal atomic absorption spectrometry. Basic toxicokinetic features were inferred from the data. The mean 8-hour time-weighted average concentration of aluminum was 1.1 (range 0.008-6.1) mg/m(3) for the shipyard and 0.13 (range 0.02-0.5) mg/m(3) for the aluminum sulfate plant. Welding fume contained aluminum oxide particles aluminum sulfate particles ranged from 1 to 10 microm in diameter. The shipyard welders' mean postshift serum and urinary concentrations of aluminum (S-Al and U-Al, respectively) were 0.22 and 3.4 micromol/l, respectively, and the aluminum sulfate workers' corresponding values were 0.13 and 0.58 micromol/l. Between two shifts, the welders' S-Al concentration decreased by about 50% (Paluminum sulfate workers. After aluminum welding at the shipyard had ceased, the median S-Al concentration decreased by about 50% (P=0.007) within a year, but there was no change (P=0.75) in the corresponding U-Al concentration. About 1% of aluminum in welding fume appears to be rapidly absorbed from the lungs, whereas an undetermined fraction is retained and forms a lung burden. A higher fractional absorption of aluminum seems possible for aluminum sulfate workers without evidence of a lung burden. After rapid absorption, aluminum is slowly mobilized from the lung burden and dominates the S-Al and U-Al concentrations of aluminum welders. For kinetic reasons, S-Al or U-Al concentrations cannot be used to estimate the accumulation of aluminum in the target organs of toxicity. However, using U-Al analysis to monitor aluminum welders' lung burden seems practical.

  10. Technology for High Pure Aluminum Oxide Production from Aluminum Scrap

    Science.gov (United States)

    Ambaryan, G. N.; Vlaskin, M. S.; Shkolnikov, E. I.; Zhuk, A. Z.

    2017-10-01

    In this study a simple ecologically benign technology of high purity alumina production is presented. The synthesis process consists of three steps) oxidation of aluminum in water at temperature of 90 °C) calcinations of Al hydroxide in atmosphere at 1100 °C) high temperature vacuum processing of aluminum alpha oxide at 1750 °C. Oxidation of aluminum scrap was carried out under intensive mixing in water with small addition of KOH as a catalyst. It was shown that under implemented experimental conditions alkali was continuously regenerated during oxidation reaction and synergistic effect of low content alkali aqueous solution and intensive mixing worked. The product of oxidation of aluminum scrap is the powder of Al(OH)3. Then it can be preliminary granulated or directly subjected to thermal treatment deleting the impurities from the product (aluminum oxide). It was shown the possibility to produce the high-purity aluminum oxide of 5N grade (99.999 %). Aluminum oxide, synthesized by means of the proposed method, meets the requirements of industrial manufacturers of synthetic sapphire (aluminum oxide monocrystals). Obtained high pure aluminum oxide can be also used for the manufacture of implants, artificial joints, microscalpels, high-purity ceramics and other refractory shapes for manufacture of ultra-pure products.

  11. Aluminum Carbothermic Technology

    Energy Technology Data Exchange (ETDEWEB)

    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

  12. 21 CFR 73.1645 - Aluminum powder.

    Science.gov (United States)

    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. It...

  13. Fundamental Studies on Aluminum Soaps

    Science.gov (United States)

    1944-06-01

    loosely bound lauric acid in aluminum dilaurate giving results accurate probably to 0.1 - 0.2# and reproducible to ubdtit ,𔃺.05^, The method...proceeds at the steady rate quoted above» Therefore the lauric acid is not hold in the form of solid solution which would give a constantly...both from lauric acid and aluminum dilaurate. It is extremely unlikely that aluminum trilaurate, AIL3, would rapidly yield dilaurate with dry acetone

  14. Pure commercial gold foils as neutron flux monitor: Neutron self-shielding assessment

    International Nuclear Information System (INIS)

    Haddad, Kh.; Haj-Hassan, H.; Helal, W.

    2007-01-01

    An assessment of pure commercial (99.9%) gold foils as neutron flux monitor was performed. A thin foils of pure commercial gold were prepared as an in-house reference material for neutron flux measurement. The assessed foils are available commercially and its cost is much less than the certified ones. Determination of the neutron self-shielding factors in these foils for both thermal and epithermal neutrons have been done experimentally. These foils show good results repeatability and good agreement with certified activation monitors. According to the well-known physical constants of the nuclide and its low cost comparing with certified foils, it can be used as an in-house reference monitor

  15. Development of Gating Foils To Inhibit Ion Feedback Using FPC Production Techniques

    Science.gov (United States)

    Arai, D.; Ikematsu, K.; Sugiyama, A.; Iwamura, M.; Koto, A.; Katsuki, K.; Fujii, K.; Matsuda, T.

    2018-02-01

    Positive ion feedback from a gas amplification device to the drift region of the Time Projection Chamber for the ILC can deteriorate the position resolution. In order to inhibit the feedback ions, MPGD-based gating foils having good electron transmission have been developed to be used instead of the conventional wire gate. The gating foil needs to control the electric field locally in opening or closing the gate. The gating foil with a GEM (gas electron multiplier)-like structure has larger holes and smaller thickness than standard GEMs for gas amplification. It is known that the foil transmits over 80 % of electrons and blocks ions almost completely. We have developed the gating foils using flexible printed circuit (FPC) production techniques including an improved single-mask process. In this paper, we report on the production technique of 335 μm pitch, 12.5 μm thick gating foil with 80 % transmittance of electrons in ILC conditions.

  16. Control of Oscillating Foil for Propulsion of Biorobotic Autonomous Underwater Vehicle (AUV

    Directory of Open Access Journals (Sweden)

    S. N. Singh

    2005-01-01

    Full Text Available The paper treats the question of control of a laterally and rotationally oscillating hydrofoil for the propulsion of biologically inspired robotic (biorobotic autonomous underwater vehicles (BAUVs. Sinusoidal oscillations of foils produce maneuvering and propulsive forces. The design is based on the internal model principle. Two springs are used to transmit forces from the actuators to the foil. Oscillating fins produce periodic forces, which can be used for fish-like propulsion and control of autonomous underwater vehicles (AUVs. The equations of motion of the foil include hydrodynamic lift and moment based on linear, unsteady, aerodynamic theory. A control law is derived for the lateral and rotational sinusoidal oscillation of the foil. In the closed-loop system, the lateral displacement and the rotational angle of the foil asymptotically follow sinusoidal trajectories of distinct frequencies and amplitudes independently. Simulation results are presented to show the trajectory tracking performance of the foil for different freestream velocities and sinusoidal command trajectories.

  17. The stripping foil test stand in the Linac4 transfer line

    CERN Document Server

    Weterings, W; Noulibos, R; Sillanoli, Y; van Trappen, P

    2015-01-01

    The 160 MeV H− beam from the Linac4 (L4) linear accelerator at CERN will be injected into the proton synchrotron booster (PSB) with a new H− charge-exchange injection system. It will include a stripping foil, to convert H− into protons by stripping off the electrons. To gain experience with these very fragile foils, prior to the installation in the PSB, and test different foil materials and thicknesses, lifetimes of the foils, the foil changing mechanism and interlocking functions, a stripping foil test stand will be installed in the L4 transfer line in 2015. This paper describes the mechanical design of the system and discusses the test possibilities and parameters.

  18. The stripping foil test stand in the Linac4 transfer line

    International Nuclear Information System (INIS)

    Weterings, W.; Bracco, C.; Noulibos, R.; Sillanoli, Y.; Trappen van, P.

    2015-01-01

    The 160 MeV H - beam from the Linac4 (L4) linear accelerator at CERN will be injected into the proton synchrotron booster (PSB) with a new H - charge-exchange injection system. It will include a stripping foil, to convert H - into protons by stripping off the electrons. To gain experience with these very fragile foils, prior to the installation in the PSB, and test different foil materials and thicknesses, lifetimes of the foils, the foil changing mechanism and interlocking functions, a stripping foil test stand will be installed in the L4 transfer line in 2015. This paper describes the mechanical design of the system and discusses the test possibilities and parameters. (author)

  19. Transmission of Fast Highly Charged Ions through a Single Glass Macrocapillary and Polycarbonate Nanocapillary Foils

    Science.gov (United States)

    Ayyad, A. M.; Dassanayake, B. S.; Keerthisinghe, D.; DeSilva, G. G.; Elkafrawy, T.; Kayani, N.; Tanis, J. A.

    2012-11-01

    Transmission of 3 MeV protons and 16 MeV O5+ ions through a single glass macrocapillary and a polycarbonate nanocapillary foil has been investigated. Results show that 3 MeV protons transmit through the capillary and the foils with little or no energy loss, while 16 MeV O5+ ions show transmission through the capillary and the foil with energy losses that vary with the tilt angle, and there are also changes in the charge state.

  20. Beam-foil-gas spectroscopy - A technique for studying steady-state non-equilibrium processes.

    Science.gov (United States)

    Bickel, W. S.; Veje, E.; Carriveau, G.; Anderson, N.

    1971-01-01

    When a thin foil is inserted in the beam of a beam-gas experiment, the beam particle state populations are driven far from their beam-gas equilibrium values. Downstream from the foil, the 'new beam' and gas species interact to produce a new equilibrium, usually different from the beam-gas equilibrium. Experimental results are presented to demonstrate this effect and to show how relative cross-section measurements can be used to study the beam-foil interaction.

  1. Stripping Foil Issues for H- Injection into the CERN PSB at 160 MeV

    CERN Document Server

    Goddard, B; Bracco, C; Carli, C; Meddahi, M; Weterings, W J M

    2010-01-01

    Beam physics considerations for the stripping foil of the 160 MeV PSB H- injection systems are described, including the arguments for the foil type, thickness, geometry and positioning. The foil performance considerations are described, including expected stripping efficiency, emittance growth, energy straggling, temperature and lifetime. The different beam loss mechanisms are quantified in the context of the aperture limits, operational considerations and collimation requirements.

  2. Experimental and theoretical analysis of a rigid rotor supported by air foil bearings

    DEFF Research Database (Denmark)

    Larsen, Jon Steffen; Hansen, Asger J. T.; Santos, Ilmar

    2015-01-01

    The popularity of compressors utilizing foil bearings is increasing. Their mechanical design is challenging, and an accurate prediction of the bearing coefficients is important. A mathematical model taking into account the foil structure, and the detailed geometry of a three pad foil bearing are ...... for the first order equation. Calculated bearing coefficients are compared to experimental results obtained from a dedicated test rig. Generally, good agreement is observed and minor discrepancies for the damping coefficients are discussed....

  3. Analysis of Cartilage-Polydioxanone Foil Composite Grafts

    Science.gov (United States)

    Kim, James H.; Wong, Brian

    2014-01-01

    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. PMID:24327249

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

    Science.gov (United States)

    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 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.

  5. Corrections in the gold foil activation method for determination of neutron beam density

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage

    1967-01-01

    A finite foil thickness and deviation in the cross section from the 1ν law imply corrections in the determination of neutron beam densities by means of foil activation. These corrections, which depend on the neutron velocity distribution, have been examined in general and are given in a specific...... example for a reactor beam transmitted through a 30 cm Bi filter. The effective cross section differs 0.5% from the capture cross section at 2200 m/s. For a 20 mg/cm2 Au foil the correction for beam attenuation and hardening through the foil is 0.7% and the activity correction is 1.5%....

  6. Development progress of wide LEU foils for Mo-99 irradiation target at KAERI

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Hwan; Son, Myung Koon; Lee, Don Bae; Lee, Byung Chul; Kim, Chang Kyu [Korea Atomic Energy Research Institute , Taejon (Korea, Republic of)

    2005-07-01

    As the uranium foils for Mo-99 irradiation target, which are charged into a reactor, can be conventionally fabricated at laboratory scale, but not yet at a commercialized scale by a hot rolling method due to some problems in foil quality, productivity and economic efficiency, an attention has shifted to the development of new improved technology. Under these circumstances, an alternative fabrication method of U polycrystalline foils has been investigated using a cooling roll casting method, in order to produce a fission isotope {sup 99}Mo, the parent nuclide of {sup 99m}Tc. The fabrication method of wide LEU foils produced by a coolingroll casting was recently developed to improve the quality of the uranium foils and the economic efficiency of the foil fabrication with modifications of the casting apparatus and adjustments of the process parameters. A continuous polycrystalline LEU foil with a thickness range of 100 to 150{mu}m and a width of about 50 mm, exceeding 5m in length for a batch procedure, could be fabricated with a better quality of the uranium foil and a higher yield of the foil fabrication, through improvements of the casting apparatus and variations of the process parameters.

  7. Development progress of wide LEU foils for Mo-99 irradiation target at KAERI

    International Nuclear Information System (INIS)

    Kim, Ki Hwan; Son, Myung Koon; Lee, Don Bae; Lee, Byung Chul; Kim, Chang Kyu

    2005-01-01

    As the uranium foils for Mo-99 irradiation target, which are charged into a reactor, can be conventionally fabricated at laboratory scale, but not yet at a commercialized scale by a hot rolling method due to some problems in foil quality, productivity and economic efficiency, an attention has shifted to the development of new improved technology. Under these circumstances, an alternative fabrication method of U polycrystalline foils has been investigated using a cooling roll casting method, in order to produce a fission isotope 99 Mo, the parent nuclide of 99m Tc. The fabrication method of wide LEU foils produced by a coolingroll casting was recently developed to improve the quality of the uranium foils and the economic efficiency of the foil fabrication with modifications of the casting apparatus and adjustments of the process parameters. A continuous polycrystalline LEU foil with a thickness range of 100 to 150μm and a width of about 50 mm, exceeding 5m in length for a batch procedure, could be fabricated with a better quality of the uranium foil and a higher yield of the foil fabrication, through improvements of the casting apparatus and variations of the process parameters

  8. Production of aluminum metal by electrolysis of aluminum sulfide

    Science.gov (United States)

    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.

  9. Foil system fatigue load environments for commercial hydrofoil operation

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

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

    1998-01-01

    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

  11. Optical observations of molecular dissociation in thin foils

    International Nuclear Information System (INIS)

    Berry, H.G.; Gay, T.J.; Brooks, R.L.

    1981-01-01

    We have measured the intensity and polarizations of light emitted from atomic excited states of dissociated molecular ions. Using HeH + projectiles, we have observed factors of 1-5 enhancements of the light from n=3, sup(1,3)P,D states of He I and some He II and H I emissions. Observations of Lyman alpha emission after dissociation of H 2 + and H 3 + show rapid variations in light yield for small internuclear separations at the foil surface. (author)

  12. Prediction of Gas Lubricated Foil Journal Bearing Performance

    Science.gov (United States)

    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.

  13. Measurement of neutron multiplication in Pb by Mn foils

    International Nuclear Information System (INIS)

    Chen Yuan; Liu Rong; Guo Haiping; Jiang Wenmian; Shen Jian

    1994-01-01

    The Leakage neutron multiplication in bulk lead has been measured using the total absorption detector and relative method. The polyethylene sphere of 138 cm in diameter is used as the moderator and total absorption detector. The measured results from 55 Mn foils and 6 Li glass are compared. The neutron multiplication is 1.74 with the lead shell of 23.1 cm thick. The measured result is consistent with the calculated one with ANISN code and ENDF/B-6 evaluated data within the experimental error. (4 figs., 3 tabs.)

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

    Science.gov (United States)

    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)].

  15. Aluminum nitride grating couplers.

    Science.gov (United States)

    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.

  16. Dynamic Property of Aluminum Foam

    Directory of Open Access Journals (Sweden)

    S Irie

    2016-09-01

    Full Text Available Aluminum in the foam of metallic foam is in the early stage of industrialization. It has various beneficial characteristics such as being lightweight, heat resistance, and an electromagnetic radiation shield. Therefore, the use of aluminum foam is expected to reduce the weight of equipment for transportation such as the car, trains, and aircraft. The use as energy absorption material is examined. Moreover aluminum foam can absorb the shock wave, and decrease the shock of the blast. Many researchers have reported about aluminum foam, but only a little information is available for high strain rates (103 s-1 or more. Therefore, the aluminum foam at high strain rates hasn't been not characterized yet. The purpose in this research is to evaluate the behavior of the aluminum form in the high-strain rate. In this paper, the collision test on high strain rate of the aluminum foam is investigated. After experiment, the numerical analysis model will be made. In this experiment, a powder gun was used to generate the high strain rate in aluminum foam. In-situ PVDF gauges were used for measuring pressure and the length of effectiveness that acts on the aluminum foam. The aluminum foam was accelerated to about 400 m/s from deflagration of single component powder and the foam were made to collide with the PVDF gauge. The high strain rate deformation of the aluminum form was measured at two collision speeds. As for the result, pressure was observed to go up rapidly when about 70% was compressed. From this result, it is understood that complete crush of the cell is caused when the relative volume is about 70%. In the next stage, this data will be compared with the numerical analysis.

  17. Photonic Crystals with Large Complete Bandgap Composed of an Approximately Ordered Array of Laurel-Crown-Like Structures Fabricated by Employing Anodic Aluminum Oxide Template

    Science.gov (United States)

    Chan, Der-Sheng; Chau, Yuan-Fong

    2013-01-01

    An innovative fabrication processes of a photonic crystal composed of an approximately ordered array of laurel-crown-like structures by employing an anodic aluminum oxide (AAO) template is presented. We found that the intensity of the electric field is affected by the microstructure and surface morphology of aluminum foil after etching the scalloped barrier oxide layer (BOL). In addition, the electric current is strongly dependent on the electric field distribution in the scalloped BOL at the pore bottoms. By using a different step potential (DSP) of 30-60 V in series, the proposed photonic crystal is fabricated and possesses a large complete photonic bandgap.

  18. Tactile multisensing on flexible aluminum nitride.

    Science.gov (United States)

    Petroni, Simona; Guido, Francesco; Torre, Bruno; Falqui, Andrea; Todaro, Maria Teresa; Cingolani, Roberto; De Vittorio, Massimo

    2012-11-21

    The integration of a polycrystalline material such as aluminum nitride (AlN) on a flexible substrate allows the realization of elastic tactile sensors showing both piezoelectricity and significant capacitive variation under normal stress. The application of a normal stress on AlN generates deformation of the flexible substrate on which AlN is grown, which results in strain gradient of the polycrystalline layer. The strain gradient is responsible for an additional polarization described in the literature as the flexoelectric effect, leading to an enhancement of the transduction properties of the material. The flexible AlN is synthesized by sputtering deposition on kapton HN (poly 4,4'-oxydiphenyl pyromellitimide) in a highly oriented crystal structure. High orientation is demonstrated by X-ray diffraction spectra (FWHM = 0.55° of AlN (0002)) and HRTEM. The piezoelectric coefficient d(33) and stress sensitive capacitance are 4.7 ± 0.5 pm V(-1) and 4 × 10(-3) pF kPa(-1), respectively. The parallel plate capacitors realized for tactile sensing present a typical dome shape, very elastic under applied stress and sensitive in the pressure range of interest for robotic applications (10 kPa to 1 MPa). The flexibility of the device finalized for tactile applications is assessed by measuring the sensor capacitance before and after shaping the sensing foil on curved surfaces for 1 hour. Bending does not affect sensor's operation, which exhibits an electrical Q factor as high as 210, regardless of the bending, and a maximum capacitance shift of 0.02%.

  19. Aluminum Nanoholes for Optical Biosensing

    Directory of Open Access Journals (Sweden)

    Carlos Angulo Barrios

    2015-07-01

    Full Text Available Sub-wavelength diameter holes in thin metal layers can exhibit remarkable optical features that make them highly suitable for (biosensing 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 (biosensing. 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.

  20. Aluminum Nanoholes for Optical Biosensing.

    Science.gov (United States)

    Barrios, Carlos Angulo; Canalejas-Tejero, Víctor; Herranz, Sonia; Urraca, Javier; Moreno-Bondi, María Cruz; Avella-Oliver, Miquel; Maquieira, Ángel; Puchades, Rosa

    2015-07-09

    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.

  1. Aluminum Nanoholes for Optical Biosensing

    Science.gov (United States)

    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

  2. Interpretive Media Study and Interpretive Social Science.

    Science.gov (United States)

    Carragee, Kevin M.

    1990-01-01

    Defines the major theoretical influences on interpretive approaches in mass communication, examines the central concepts of these perspectives, and provides a critique of these approaches. States that the adoption of interpretive approaches in mass communication has ignored varied critiques of interpretive social science. Suggests that critical…

  3. Kinetics of the oxidation of Zn foils in air atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Baca, R; Martinez, J [Centro de Investigacion de Dispositivos Semiconductores, BUAP, Puebla. C.P. 72570 (Mexico); Kryshtab, T [Departamento de Ciencias de Materiales, ESFM - IPN, Mexico D.F (Mexico); Juarez, G; Solache, H; Andraca, J; Garcia, O; Pena-Sierra, R, E-mail: rbaca02006@yahoo.com.mx

    2010-02-15

    The formation kinetics of ZnO thin films grown by oxidation of polycrystalline Zn foils in air atmosphere at temperatures below the melting point is reported. Previous to the oxidation process the Zn foils were polished to produce mirror-like finished surfaces. The growth rate of the ZnO films was monitored by ellipsometric measurements. The growth rate of the ZnO films under 100 nm follows a linear and parabolic behavior in accordance with previously reported studies. The thicknesses of the films strongly influence the appearance of the final produced ZnO surface. The ZnO films surfaces with thicknesses less than 100 nm resulted uniform with low rms roughness. However as the films become thicker the rms roughness increased and a uniform distribution of whiskers was observed. X-ray diffraction and photoluminescence (PL) studies were done on the ZnO films to find out their structural and optical characteristics. PL spectra on the films are composed by two main bands; a weak near-band gap in the ultraviolet region and a strong but well defined green band. A discussion is included on the origins of the observed PL spectra.

  4. Modelling Accumulator Stripper Foil Heating for ESSNUSB Facility

    CERN Document Server

    Martini, Michel

    2015-01-01

    It is proposed to use the 2.0 GeV, 5 MW proton linac, 2.86 ms long pulses at 14 Hz of the European Spallation Source [1], [2] being built in Lund, Sweden to deliver, alternately with the spallation neutron production a very intense neutrino beam to enable the discovery of leptonic CP violation. To this end the linac would be upgraded to supply, in addition to the 2.86 ms long proton pulses at 14 Hz, four 0.72 ms H short pulses at 70 Hz for neutrino production. Because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production will need to be compressed to a few s with the aid of an accumulator ring. Charge exchange injection of an H- beam from the linac will be used, the linac delivering 1.1E15 H- per pulse. This paper is about stripping foil heating considerations, emphasizing the detailed evaluation of the foil temperature over the multiple ring re-fills

  5. Effect of defence response time during lunge in foil fencing.

    Science.gov (United States)

    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.

  6. Pengaruh Posisi Foil Terhadap Gaya Angkat Dan Hambatan Kapal Katamaran

    Directory of Open Access Journals (Sweden)

    Muhammad Rizki Darmawan Adi Kusuma

    2017-08-01

    Full Text Available Perkembangan teknologi dalam dunia perkapalan terjadi sangat pesat, mulanya kapal memiliki satu lambung (monohull, kemudian berkembang dengan munculnya kapal katamaran atau memiliki dua lambung, kapal katamaran memiliki banyak kelebihan dibanding dengan monohull mulai dari segi hambatan, olah gerak, dan lain-lain. Kapal katamaran akhirnya dikembangkan lagi dengan menjadikannya kapal hydrofoil yang bertujuan untuk mengurangi hambatan. Hydrofoil adalah sebuah kapal dengan bagian seperti sayap yang dipasang pada penyangga di bawah lambung kapal yang digunakan untuk mengangkat lambung kapal, pada saat kapal mencapai kecepatan tinggi yang menyebabkan pengurangan hambatan. Pada penelitian ini bertujuan untuk mendapatkan konfigurasi posisi foil yang menghasilkan gaya angkat paling besar serta hambatan yang paling kecil. Dalam melaksanakan penelitian ini penulis menggunakan program komputer berbasis Computational Fluid Dynamic(CFD untuk penyelesaian masalah dari tujuan penelitian, Computational fluid dynamic(CFD merupakan ilmu sains dalam penentuan penyelesaian numerik dinamika fluida.Penelitian dilakukan dengan cara menganalisa dan menghitung hambatan total kapal menggunakan model.Berdasarkan hasil analisa menggunakan software Tdyn 12.2.3.0 didapatkan nilai hambatan untuk berbagai variasi konfigurasi foil. Nilai hambatan total dapat diperkecil  hingga 37,56%, nilai ini terjadi pada Froude Number 1,737 pada variasi konfigurasi Canard dengan konfigurasi 65%(aft dan 35%(fore.

  7. System requirements for the Los Alamos foil-implosion project

    International Nuclear Information System (INIS)

    Brownell, J.; Bowers, R.; Greene, A.; Lindemuth, I.; Nickel, G.; Oliphant, T.; Weiss, D.

    1983-01-01

    The goal of the Los Alamos imploding foil project is the development of an intense source of soft x rays and hot plasma produced from the thermalization of 1 to 10 MJ of plasma kinetic energy. The source will be used for material studies and fusion experiments. Specifically, thin, current-carrying cylindrical metallic plasmas are imploded via their self-magnetic forces. Features of this project are the use of high-explosive-driven flux-compression generators as the prime power source to achieve very high energies and fast opening switches to shorten the electrical pulses. To reach a load kinetic energy of 10 MJ, it is expected that the foil-plasma must carry about 50 MA of current and must implode in less than 1/2 μsec. This imposes the requirements that switch opening times must be less than 1/2 μsec and the transmission line must withstand voltages of about 1 MV. The system being pursued at Los Alamos is described, and model calculations are presented

  8. Kinetics of the oxidation of Zn foils in air atmosphere

    Science.gov (United States)

    Baca, R.; Juárez, G.; Solache, H.; Andraca, J.; Martinez, J.; Garcia, O.; Kryshtab, T.; Peña-Sierra, R.

    2010-02-01

    The formation kinetics of ZnO thin films grown by oxidation of polycrystalline Zn foils in air atmosphere at temperatures below the melting point is reported. Previous to the oxidation process the Zn foils were polished to produce mirror-like finished surfaces. The growth rate of the ZnO films was monitored by ellipsometric measurements. The growth rate of the ZnO films under 100 nm follows a linear and parabolic behavior in accordance with previously reported studies. The thicknesses of the films strongly influence the appearance of the final produced ZnO surface. The ZnO films surfaces with thicknesses less than 100 nm resulted uniform with low rms roughness. However as the films become thicker the rms roughness increased and a uniform distribution of whiskers was observed. X-ray diffraction and photoluminescence (PL) studies were done on the ZnO films to find out their structural and optical characteristics. PL spectra on the films are composed by two main bands; a weak near-band gap in the ultraviolet region and a strong but well defined green band. A discussion is included on the origins of the observed PL spectra.

  9. Monte Carlo transport of electrons and positrons through thin foils

    International Nuclear Information System (INIS)

    Legarda, F.; Idoeta, R.

    2000-01-01

    In the different measurements made with electrons traversing matter it becomes useful the knowledge of its transmission through that medium, their paths and their angular distribution through matter so as to process and get information about the traversed medium and to improve and innovate the techniques that employ electrons, as medical applications or materials irradiation. This work presents a simulation of the transport of beams of electrons and positrons through thin foils using an analog Monte Carlo code that simulates in a detailed way every electron movement or interaction in matter. As those particles penetrate thin absorbers it has been assumed that they interact with matter only through elastic scattering, with negligible energy loss. This type of interaction has been described quite precisely because its angular form influences very much the angular distribution of electrons and positrons in matter. With this code it has been calculated the number of particles, with energies between 100 and 3000 keV, that are transmitted through different media of various thicknesses as well as its angular distribution, showing a good agreement with experimental data. The discrepancies are less than 5% for thicknesses lower than about 30% of the corresponding range in the tested material. As elastic scattering is very anisotropic, angular distributions resemble a collimated incident beam for very thin foils becoming slowly more isotropic when absorber thickness is increased. (author)

  10. Real Time Ultrasonic Aluminum SPOT Weld Monitoring System

    Science.gov (United States)

    Regalado, W. Pérez; Chertov, A. M.; Maev, R. Gr.

    2010-02-01

    Aluminum alloys pose several properties that make them one of the most popular engineering materials: they have excellent corrosion resistance, and high weight-to-strength ratio. Resistance spot welding of aluminum alloys is widely used today but oxide film and aluminum thermal and electrical properties make spot welding a difficult task. Electrode degradation due to pitting, alloying and mushrooming decreases the weld quality and adjustment of parameters like current and force is required. To realize these adjustments and ensure weld quality, a tool to measure weld quality in real time is required. In this paper, a real time ultrasonic non-destructive evaluation system for aluminum spot welds is presented. The system is able to monitor nugget growth while the spot weld is being made. This is achieved by interpreting the echoes of an ultrasound transducer located in one of the welding electrodes. The transducer receives and transmits an ultrasound signal at different times during the welding cycle. Valuable information of the weld quality is embedded in this signal. The system is able to determine the weld nugget diameter by measuring the delays of the ultrasound signals received during the complete welding cycle. The article presents the system performance on aluminum alloy AA6022.

  11. Aluminum anode for aluminum-air battery - Part I: Influence of aluminum purity

    Science.gov (United States)

    Cho, Young-Joo; Park, In-Jun; Lee, Hyeok-Jae; Kim, Jung-Gu

    2015-03-01

    2N5 commercial grade aluminum (99.5% purity) leads to the lower aluminum-air battery performances than 4N high pure grade aluminum (99.99% purity) due to impurities itself and formed impurity complex layer which contained Fe, Si, Cu and others. The impurity complex layer of 2N5 grade Al declines the battery voltage on standby status. It also depletes discharge current and battery efficiency at 1.0 V which is general operating voltage of aluminum-air battery. However, the impurity complex layer of 2N5 grade Al is dissolved with decreasing discharge voltage to 0.8 V. This phenomenon leads to improvement of discharge current density and battery efficiency by reducing self-corrosion reaction. This study demonstrates the possibility of use of 2N5 grade Al which is cheaper than 4N grade Al as the anode for aluminum-air battery.

  12. Optimizing dc-resistance of a foil wounded toroidal inductor combining matlab and comsol

    DEFF Research Database (Denmark)

    Schneider, Henrik; Andersen, Thomas; Knott, Arnold

    2013-01-01

    An optimization routine is presented to optimize the shape of a foil winding of a toroid inductor in terms of the DC resistance. MATLAB was used to define the geometry of the foil winding and COMSOL was used to import the geometry and create a 3D finite element model. The initial parameters...

  13. Prism Foil from an LCD Monitor as a Tool for Teaching Introductory Optics

    Science.gov (United States)

    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…

  14. Large area flexible lighting foils using distributed bare LED dies on polyester substrates

    NARCIS (Netherlands)

    Ende, D.A. van den; Kusters, R.H.L.; Cauwe, M.; Waal, A. van der; Brand, J. van den

    2013-01-01

    Integration of LEDs on flexible foil substrates is of interest for flexible lighting applications and for backlights for flexible displays. Such a large area lighting device can be made by integrating a matrix of closely spaced LEDs on a flexible foil substrate. Preferably, these LEDs are integrated

  15. Vortex-wake interactions of a flapping foil that models animal swimming and flight

    NARCIS (Netherlands)

    Lentink, D.; Muijres, F.T.; Donker-Duyvis, F.J.; Leeuwen, van J.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

  16. Long-Term Memory for Pictures under Conditions of Difficult Foil Discriminability.

    Science.gov (United States)

    Homa, Donald; Viera, Cynthia

    Research has demonstrated that subjects are sensitive to both thematic and non-thematic information in pictorial stimuli. Three experiments were conducted to investigate memory for pictures under conditions of difficult foil discriminability and lengthy retention intervals. The foils differed from the studied persons in the number and quality of…

  17. Bonding bare die LEDs on PET foils for lighting applications: Thermal design modeling and bonding experiments

    NARCIS (Netherlands)

    Ende, D.A. van den; Kusters, R.H.L.; Cauwe, M.; Waal, A. van der; Brand, J. van den

    2012-01-01

    Integration of LEDs on flexible foil substrates is of interest for flexible lighting applications and flexible photonic devices. A matrix of LEDs on a foil combined with a diffuser can be a potential alternative for flexible OLED lighting devices. Preferably, these LEDs are integrated in an

  18. Corrections in the gold foil activation method for determination of neutron beam density

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage

    1967-01-01

    A finite foil thickness and deviation in the cross section from the 1ν law imply corrections in the determination of neutron beam densities by means of foil activation. These corrections, which depend on the neutron velocity distribution, have been examined in general and are given in a specific...

  19. Identification of stiffness and damping characteristics of axial air-foil bearings

    NARCIS (Netherlands)

    Arora, Vikas; Arora, Vikas; van der Hoogt, Peter; Aarts, Ronald G.K.M.; de Boer, Andries

    2011-01-01

    Air-foil bearings (AFBs) 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 the layer or layers underneath provide an elastic foundation. AFBs are currently used in

  20. Aluminum plasmonic photocatalysis

    Science.gov (United States)

    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

  1. Determination of Sandoz Black Aluminum Coloring Dye Olive Aluminum Coloring Dye and Sodium Dichromate Aluminum Sealing Solutions by UV-Visible Spectrophotometry

    National Research Council Canada - National Science Library

    Sopok, Samuel

    1992-01-01

    The chemical literature lacks an acceptable method to determine and adequately control Sandoz black aluminum coloring dye, olive aluminum coloring dye, and sodium dichromate aluminum sealing solutions...

  2. Spray Rolling Aluminum Strip

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Irradiation tests of 99Mo isotope production targets employing uranium metal foils

    International Nuclear Information System (INIS)

    Hofman, G.L.; Wiencek, T.C.; Wood, E.L.; Snelgrove, J.L.; Suripto, A.; Nasution, H.; Lufti-Amin, D.; Gogo, A.

    1996-01-01

    Most of the world's supply of 99 mTc for medical purposes is currently produced from the decay of 99 Mo derived from the fissioning of high-enriched uranium (HEU). Substitution of low-enriched uranium (LEU) metal foils for the HEU UO 2 used in current target designs will allow equivalent 99 Mo yields with little change in target geometries. Substitution of uranium metal for uranium alloy and aluminide in other target designs will also allow the conversion of HEU to LEU. Several uranium-metal-foil targets have been fabricated at ANL and irradiated to prototypic burnup in the Indonesian RSG-GAS reactor. Postirradiation examination of the initial test indicated that design modifications were required to allow the irradiated foil to be removed for chemical processing. The latest test has shown good irradiation behavior, satisfactory dismantling and foil removal when the U-foil is separated from its containment by metallic, fission-recoil absorbing barriers. (author)

  4. Foil assisted replica molding for fabrication of microfluidic devices and their application in vitro.

    Science.gov (United States)

    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.

  5. Lead foil in dental X-ray film: Backscattering rejection or image intensifier?

    Energy Technology Data Exchange (ETDEWEB)

    Hönnicke, M.G., E-mail: marcelo.honnicke@unila.edu.br [Universidade Federal da Integração Latino-Americana, Foz do Iguaçu (Brazil); Delben, G.J. [Faculdade de Tecnologia Tupy, Curitiba (Brazil); Godoi, W.C. [Universidade Tecnológica Federal do Paraná, Curitiba (Brazil); Swinka-Filho, V. [Instituto de Tecnologia para o Desenvolvimento – LACTEC, Curitiba (Brazil)

    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.

  6. Room temperature thin foil SLIM-cut using an epoxy paste: experimental versus theoretical results

    International Nuclear Information System (INIS)

    Bellanger, Pierre; Serra, Joao; Bouchard, Pierre-Olivier; Bernacki, Marc

    2015-01-01

    The stress induced lift-off method (SLIM) -cut technique allows the detachment of thin silicon foils using a stress inducing layer. In this work, results of SLIM-cut foils obtained using an epoxy stress inducing layer at room temperature are presented. Numerical analyses were performed in order to study and ascertain the important experimental parameters. The experimental and simulation results are in good agreement. Indeed, large area (5 × 5 cm 2 ) foils were successfully detached at room temperature using an epoxy thickness of 900 μm and a curing temperature of 150 °C. Moreover, three foils (5 × 3 cm 2 ) with thickness 135, 121 and 110 μm were detached from the same monocrystalline substrate. Effective minority carrier lifetimes of 46, 25 and 20 μs were measured using quasi-steady-state photoconductance technique in these foils after iodine ethanol surface passivation. (paper)

  7. Nondestructive analysis of silver in gold foil using synchrotron radiation X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Kasamatsu, Masaaki; Suzuki, Yasuhiro; Suzuki, Shinichi; Nakanishi, Toshio; Shimoda, Osamu; Nishiwaki, Yoshinori; Miyamoto, Naoki

    2005-01-01

    Small particles of gold foil detached from an indoor decoration might be important evidence to associate a suspect with a crime scene. We have investigated the application of elemental analysis using synchrotron radiation X-ray fluorescence spectrometry to discriminate small particles of gold foil. Eight kinds of gold foil samples collected in Japan were used in the experiments. As a result of synchrotron radiation X-ray fluorescence spectrometry, only two elements, gold and silver, were detected from all gold foil samples. The intensity ratios of AgK α /AuL α showed good correlation with the content ratios of Ag/Au. The variation of intensity ratio within a same sample was sufficiently small compared with those of different samples. Therefore the comparison of this intensity ratio can be an effective method to discriminate small particles originating from different types of gold foil. (author)

  8. Design, fabrication, and performance of foil journal bearing for the brayton rotating unit

    Science.gov (United States)

    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.

  9. Irradiation tests of 99Mo isotope production targets employing uranium metal foils

    International Nuclear Information System (INIS)

    Hofman, G.L.; Wiencek, T.C.; Wood, E.L.; Snelgrove, J.L.; Suripto, A.; Nasution, H.; Lufti-Amin, D.; Gogo, A.

    1996-01-01

    Most of the world's supply of 99m Tc for medical purposes is currently produced form the decay of 99 Mo derived from the fissioning of high-enriched uranium (HEU). Substitution of low-enriched uranium (LEU) metal foils for the HEU UO 2 used in current target designs will allow equivalent 99 Mo yields with little change in target geometries. Substitution of uranium metal for uranium alloy and aluminide in other target designs will also allow the conversion of HEU to LEU. Several uranium-metal-foil targets have been fabricated at ANL and irradiated to prototypic burnup in the Indonesian RSG-GAS reactor. Postirradiation examination of the initial test indicated that design modifications were required to allow the irradiated foil to be removed for chemical processing. The latest test has shown good irradiation behavior, satisfactory dismantling and foil removal when the U-foil is separated from its containment by metallic, fission-recoil absorbing barriers

  10. Report on Plasma Spraying of Full-Sized Foils (FY13)

    Energy Technology Data Exchange (ETDEWEB)

    Hollis, Kendall J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-02-27

    This report is the deliverable fulfilling task B40700. The application of the Zr diffusion barrier between the U-­Mo fuel and the Al cladding has been an ongoing area of research [1-8]. The goal of the research described in this report was to demonstrate the plasma spraying technique for depositing zirconium (Zr) onto full sized U-Mo foils to demonstrate scale up of the process from the mini foil samples (1”x4”x ~0.015”) coated previously. Full size denotes one of the actual fuel foil sizes for one of the five research reactors (MURR, NIST, MIT, HFIR, ATR) to be converted to LEU fuel in the US research reactor Convert program. The smallest full sized fuel foil is for the NIST reactor with a size of 11.37”x2.436”x0.020”. The largest full sized fuel foil is for the ATR reactor with a size of 48.01”x3.43”x0.020”. The widest full sized fuel foil is for the MURR reactor with a size of 24”x4.052”x0.020”. The current LANL vacuum plasma spray system can accommodate a foil length of 24” or less. Therefore, as a demonstration of the widest foil in the program and the maximum length foil that can be processed on the current LANL system, a nominal 24”x4”x0.020” foil was chosen as the goal for scale up activities.

  11. Aluminum hydroxide issue closure package

    International Nuclear Information System (INIS)

    Bergman, T.B.

    1998-01-01

    Aluminum hydroxide coatings on fuel elements stored in aluminum canisters in K West Basin were measured in July and August 1998. Good quality data was produced that enabled statistical analysis to determine a bounding value for aluminum hydroxide at a 99% confidence level. The updated bounding value is 10.6 kg per Multi-Canister Overpack (MCO), compared to the previously estimated bounding value of 8 kg/MCO. Thermal analysis using the updated bounding value, shows that the MCO generates oxygen concentrate that are below the lower flammability limits during the 40-year interim storage period and are, therefore, acceptable

  12. PREPARATION OF URANIUM-ALUMINUM ALLOYS

    Science.gov (United States)

    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)

  13. Test preparation and lifetime measurement of very thin carbon stripper foils made by a controlled DC arc-discharge method

    CERN Document Server

    Sugai, I; Oyaizu, M; Kawakami, H; Hattori, Y; Kawasaki, K; Hayashizaki, N

    2002-01-01

    We have prepared very thin plastic supported carbon stripper foils (1.2+-0.3 mu g/cm sup 2) using a controlled DC arc-discharge (CDAD) method. The lifetime of these foils was measured with 3.2 MeV Ne sup + ions. These foils recorded lifetimes about four times longer at the maximum and three times longer on the average than those commercially available foils produced by evaporation-condensation.

  14. New membranes obtained by grafted irradiated PVDF foils

    Energy Technology Data Exchange (ETDEWEB)

    Mazzei, R. [Unidad de Actividades Tecnologicas y Agropecuarias, Laboratorio de Polimeros, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Universidad Tecnologica Nacional Facultad Regional, Buenos Aires (Argentina); Garcia Bermudez, G. [Gerencia de Investigacion y Aplicaciones, Laboratorio Tandar, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad Nacional de General San Martin, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); Camporotondi, D.E., E-mail: camporotondi@cae.cnea.gov.ar [Unidad de Actividades Tecnologicas y Agropecuarias, Laboratorio de Polimeros, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Arbeitman, C. [Gerencia de Investigacion y Aplicaciones, Laboratorio Tandar, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); and others

    2012-09-15

    The present work describes a new method to produce membranes of poly(Acrylic-acid-Xmonomer) using the grafting procedure. PVDF foils irradiated with Ar{sup +} beam with energies between 30 and 150 keV were employed as substratum. Different combinations of monomers in water solutions were used: acrylic acid (AAc); acrylic acid-glycidyl methacrylate (AAc-GMA); acrylic acid-styrene (AAc-S), acrylic acid-N-isopropyl acrylamide (AAc-NIPAAm) and acrylic acid-N-isopropyl acrylamide-glycidyl methacrylate (AAc-NIPAAm-GMA). A large percentage of grafting results for specific values of: ion fluence and energy, AAc and sulfuric acid concentration, and different substrata PVDF polymorphous (alpha or beta). At a particular time of the grafting process, the poly(AAc-Xmonomer) membranes detach from the substratum and continue their grafting in the solution. This method is useful to produce increased replicated membranes of the irradiated original surface.

  15. Synthesis of Homogenous Bilayer Graphene on Industrial Cu Foil

    Science.gov (United States)

    Luo, Wen-Gang; Wang, Hua-Feng; Cai, Kai-Ming; Han, Wen-Peng; Tan, Ping-Heng; Hu, Ping-An; Wang, Kai-You

    2014-06-01

    We synthesize the homogenous graphene films on cheap industrial Cu foils using low pressure chemical vapor deposition. The quality and the number of layers of graphene are characterized by Raman spectra. Through carefully tuning the growth parameters, we find that the growth temperature, hydrocarbon concentration and the growth time can substantially affect the growth of high-quality graphene. Both single and bilayer large size homogenous graphenes have been synthesized in optimized growth conditions. The growth of graphene on Cu surface is found to be self ceasing in the bilayer graphene process with the low solubility of carbon in Cu. Furthermore, we have optimized the transfer process, and clear graphene films almost free from impurity are successfully transferred onto Si/SiO2 substrates. The field effect transistors of bilayer graphene are fabricated, which demonstrates a maximum hole (electron) mobility of 4300 cm2 V-1s-1 (1920 cm2V-1s-1) at room temperature.

  16. Visualization of terahertz surface waves propagation on metal foils

    Science.gov (United States)

    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

  17. Standard test methods of tension testing of metallic foil

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1993-01-01

    1.1 These test methods cover the tension testing of metallic foil at room temperature in thicknesses less than 0.006 in. (0.150 mm). Note 1—Exception to these methods may be necessary in individual specifications or test methods for a particular material. 1.2 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  18. Deposition of selenium coatings on beryllium foils. Revision 1

    International Nuclear Information System (INIS)

    Erikson, E.D.; Tassano, P.L.; Reiss, R.H.; Griggs, G.E.

    1984-01-01

    A technique for preparing selenium films on 50.8 micrometers thick beryllium foils is described. The selenium was deposited in vacuum from a resistance heated evaporation source. A water-cooled enclosure was used to minimize contamination of the vacuum system and to reduce the exposure of personnel to toxic and obnoxious materials. Profilometry measurements of the coatings indicated selenium thicknesses of 5.5, 12.9, 37.5, 49.8 and 74.5 micrometers. The control of deposition rate and of coating thickness was facilitated using a commercially available closed-loop programmable deposition controller. The x-ray transmission of the coated substrates was measured using a tritiated zirconium source. The transmissivities of the film/substrate combination are presented for the range of energies from 4 to 20 keV

  19. The foil equilibration method for carbon in sodium

    International Nuclear Information System (INIS)

    Borgstedt, H.; Frees, G.; Peric, Z.

    1980-01-01

    Among the non-metallic impurities in sodium, carbon plays an important role since at high temperatures the structural materials exposed to sodium are subject to carburization and decarburization depending on the carbon activity of the sodium. Carburization of austenitic stainless steels leads to reduction in ductility and fatigue properties whereas decarburization results in a decrease in the high temperature creep strength. A knowledge of the carbon activities in sodium will help understanding of the carbon transfer phenomena in operating sodium systems of the fast reactors, and also carbon diffusion, microstructural stability and mechanical behaviour of materials under different service conditions. An understanding of the carbon behaviour in sodium becomes difficult in view of the complexities of the different species present as elemental carbon, carbide, acetylide, carbonate, and cyanide. Carbon estimation techniques for sodium presently in use are: chemical analytical methods, on-line carbon monitors, and oil equilibration method. Various chemical methods have been developed for the estimation of different species like acetylide, cyanide, carbonate, elemental carbon, and total carbon in sodium. All these methods are time consuming and subject to various errors. The on-line monitors developed for carbon in sodium are able to give continuous indication of carbon activities and have higher sensitivity than the chemical methods. A still more simple method for the determination of carbon activities is by the foil equilibration first published by Natesan et al. Because of its simplicity like the vanadium wire equilibration for oxygen it is being used widely for the estimation of carbon activities in sodium systems. Carbon concentrations in operating sodium systems estimated by this procedure by applying solubility relation to carbon activities have yielded very low values of carbon, lower than the sensitivity limits of the chemical estimation methods. Foil

  20. Influence of copper foil polycrystalline structure on graphene anisotropic etching

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Kamal P. [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Mahyavanshi, Rakesh D. [Department of Physical Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Kalita, Golap, E-mail: kalita.golap@nitech.ac.jp [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Department of Physical Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Tanemura, Masaki [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Department of Physical Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan)

    2017-01-30

    Graphical abstract: Hexagonal hole formation with anisotropic etching 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. - Highlights: • Reveal the influence of copper polycrystalline structure on anisotropic etching of graphene. • Hexagonal hole formation with etching is observed to be independent of stripes and wrinkles in graphene. • Variation in etched pattern of graphene depending on the base Cu grain is confirmed. • This finding will help to understand the nature of microscopic etched pattern in graphene. - Abstract: 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

  1. An Interpreter's Interpretation: Sign Language Interpreters' View of Musculoskeletal Disorders

    National Research Council Canada - National Science Library

    Johnson, William L

    2003-01-01

    ...; interpreting style, such as poor body posture, tensing muscles, signing too forcefully; job control, including the emotional and physical stress of the job, being overworked, and disliking the job...

  2. Fouling corrosion in aluminum heat exchangers

    Directory of Open Access Journals (Sweden)

    Su Jingxin

    2015-06-01

    Full Text Available Fouling deposits on aluminum heat exchanger reduce the heat transfer efficiency and cause corrosion to the apparatus. This study focuses on the corrosive behavior of aluminum coupons covered with a layer of artificial fouling in a humid atmosphere by their weight loss, Tafel plots, electrochemical impedance spectroscopy (EIS, and scanning electron microscope (SEM observations. The results reveal that chloride is one of the major elements found in the fouling which damages the passive film and initiates corrosion. The galvanic corrosion between the metal and the adjacent carbon particles accelerates the corrosive process. Furthermore, the black carbon favors the moisture uptake, and gives the dissolved oxygen greater chance to migrate through the fouling layer and form a continuous diffusive path. The corrosion rate decreasing over time is conformed to electrochemistry measurements and can be verified by Faraday’s law. The EIS results indicate that the mechanism of corrosion can be interpreted by the pitting corrosion evolution mechanism, and that pitting was observed on the coupons by SEM after corrosive exposure.

  3. Determination of half-value thickness of aluminum foils for different beta sources by using fractional calculus

    Energy Technology Data Exchange (ETDEWEB)

    Şen, Mürsel, E-mail: senmursel@hotmail.com [Department of Physics, Institute of Science and Technology, Dumlupınar University, Kütahya 43100 (Turkey); Çalık, Abdullah Engin, E-mail: aengin.calik@dpu.edu.tr [Department of Physics, Arts and Sciences Faculty, Dumlupınar University, Kütahya 43100 (Turkey); Ertik, Hüseyin, E-mail: huseyinertik@akdeniz.edu.tr [Department of Mathematics Education, Alanya Faculty of Education, Akdeniz University, Alanya, Antalya 07425 (Turkey)

    2014-09-15

    Reduction of beta-ray intensity with respect to thickness of absorber material exhibits a non-exponential behavior due to the different types of the energy loss processes and many different fractal-like paths followed by beta particles in material. According to Caputo formalism of fractional calculus, the reduction process of beta-ray intensity is governed by using a simple fractional differential equation of order α ≈ 0.31. The solution is obtained in terms of Mittag–Leffler function which depends on a mass attenuation coefficient μ{sub m} and a fractional order α that can be considered as a measure of fractality of absorbing material. In the experimental part of the study, {sup 99}Tc, {sup 36}Cl, {sup 14}C, {sup 210}Pb and {sup 147}Pm radioisotopes have been used as beta sources. In the framework of fractional calculus approach, the experimental and calculated half-value thicknesses of all samples have been obtained in agreement with each other.

  4. Chrome - Free Aluminum Coating System

    Science.gov (United States)

    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.

  5. Optomechanics of Single Aluminum Nanodisks.

    Science.gov (United States)

    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.

  6. Transient oxidation of Al-deposited Fe-Cr-Al alloy foil

    International Nuclear Information System (INIS)

    Andoh, A.

    1997-01-01

    The oxide phases formed on an Al-deposited Fe-Cr-Al alloy foil and an Fe-Cr-Al alloy foil of the same levels of Al and (La+Ce) contents, and their oxidation kinetics have been studied in air at 1173 and 1373 K using TGA, XRD and SEM. Al deposition promotes the growth of metastable aluminas (θ-Al 2 O 3 , γ-Al 2 O 3 ). Scales consisting of θ-Al 2 O 3 and a small amount of α-Al 2 O 3 develop on the Al-deposited foil at 1173 K and exhibit the whisker-type morphology. In the early stage of oxidation at 1373 K, thick scales consisting of θ-Al 2 O 3 and α-Al 2 O 3 grow rapidly on the Al-deposited foil. The transformation from θ-Al 2 O 3 to α-Al 2 O 3 is very fast, and the scales result in only α-Al 2 O 3 . In contrast, α-Al 2 O 3 scales containing a minor amount of FeAl 2 O 4 develop on the alloy foil. The growth rate of α-Al 2 O 3 scales on the Al-deposited foil is smaller than that on the alloy foil and very close to that on NiAl at 1373 K. (orig.)

  7. An Assessment of Gas Foil Bearing Scalability and the Potential Benefits to Civilian Turbofan Engines

    Science.gov (United States)

    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.

  8. Interpreting Impoliteness: Interpreters’ Voices

    Directory of Open Access Journals (Sweden)

    Tatjana Radanović Felberg

    2017-11-01

    Full Text Available Interpreters in the public sector in Norway interpret in a variety of institutional encounters, and the interpreters evaluate the majority of these encounters as polite. However, some encounters are evaluated as impolite, and they pose challenges when it comes to interpreting impoliteness. This issue raises the question of whether interpreters should take a stance on their own evaluation of impoliteness and whether they should interfere in communication. In order to find out more about how interpreters cope with this challenge, in 2014 a survey was sent to all interpreters registered in the Norwegian Register of Interpreters. The survey data were analyzed within the theoretical framework of impoliteness theory using the notion of moral order as an explanatory tool in a close reading of interpreters’ answers. The analysis shows that interpreters reported using a variety of strategies for interpreting impoliteness, including omissions and downtoning. However, the interpreters also gave examples of individual strategies for coping with impoliteness, such as interrupting and postponing interpreting. These strategies border behavioral strategies and conflict with the Norwegian ethical guidelines for interpreting. In light of the ethical guidelines and actual practice, mapping and discussing different strategies used by interpreters might heighten interpreters’ and interpreter-users’ awareness of the role impoliteness can play in institutional interpreter– mediated encounters. 

  9. Aluminum and Alzheimer's Disease.

    Science.gov (United States)

    Colomina, Maria Teresa; Peris-Sampedro, Fiona

    2017-01-01

    Aluminum (Al) is one of the most extended metals in the Earth's crust. Its abundance, together with the widespread use by humans, makes Al-related toxicity particularly relevant for human health.Despite some factors influence individual bioavailability to this metal after oral, dermal, or inhalation exposures, humans are considered to be protected against Al toxicity because of its low absorption and efficient renal excretion. However, several factors can modify Al absorption and distribution through the body, which may in turn progressively contribute to the development of silent chronic exposures that may lately trigger undesirable consequences to health. For instance, Al has been recurrently shown to cause encephalopathy, anemia, and bone disease in dialyzed patients. On the other hand, it remains controversial whether low doses of this metal may contribute to developing Alzheimer's disease (AD), probably because of the multifactorial and highly variable presentation of the disease.This chapter primarily focuses on two key aspects related to Al neurotoxicity and AD, which are metabolic impairment and iron (Fe) alterations. We discuss sex and genetic differences as a plausible source of bias to assess risk assessment in human populations.

  10. Managing aluminum phosphide poisonings

    Science.gov (United States)

    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

  11. Poster - Thur Eve - 27: Scattering foil redesign for modulated electron radiotherapy.

    Science.gov (United States)

    Connell, T; Seuntjens, J

    2012-07-01

    This work serves to build on existing work that discussed the advantages of removing the scattering foil from the beamline for modulated electron radiotherapy (MERT) much like flattening filter-free beams in photon IMRT. Due to concerns about the ability of the accelerators transmission ionization chamber to function normally with narrow, minimally-scattered beams as well as a limited maximum field size, this study focused on the design of a new custom scattering foil that was optimized for MERT applications. Different foil parameters such as material, thickness and shape were investigated to produce a minimally scattered beam, as opposed to a flat beam in the case of the clinical foil, while preserving the dosimetric benefits of a reduced thickness foil such as dramatically higher dose rate and reduced photon contamination in the bremsstrahlung tail. Using a Monte Carlo model that was verified against measured data, fluence profiles at the level of the transmission ionization chamber were produced and analyzed for all foil configurations, as well as PDDs and profiles in a water phantom. It was found that a simple foil of slab geometry made of low to medium Z material with the thickness determined by the maximum desirable field size and chosen electron energy produced a sufficiently scattered beam that maintained the dosimetric advantages of a scattering-foil-free beamline. These new foils, when applied to MERT, have the advantage of reducing treatment time due to higher dose rates and reducing dose to healthy tissue due to reduced dose in the bremsstrahlung tail. © 2012 American Association of Physicists in Medicine.

  12. Reconstruction of the nasal septum using perforated and unperforated polydioxanone foil.

    Science.gov (United States)

    Tweedie, Daniel J; Lo, Stephen; Rowe-Jones, Julian M

    2010-01-01

    To present our experience of reconstruction of the nasal septum using perforated and unperforated foils, particularly with respect to functional and aesthetic sequelae. A retrospective medical record review of a prospectively conducted case series was undertaken of all consecutive patients who underwent septal reconstruction using polydioxanone foil in a 4-year period. Procedures included septorhinoplasty and isolated septoplasty via external and endonasal approaches using corporeal and extracorporeal techniques. The polydioxanone foils were in battens or sheets. Fifty patients underwent septal reconstruction using unperforated (first 26 patients) or perforated (next 24 patients) polydioxanone foil. Median total postoperative follow-up was 51.5 months (range, 34-60 months) for unperforated foil and 20.5 months (range, 12-31 months) for perforated foil. All the patients were reviewed for assessment of appearance and function. Forty-three patients had satisfactory results, needing no further treatment. Three patients required minor septal or tip revision surgery. Four patients experienced moderate saddling of the dorsum (all involved unperforated polydioxanone foil) and underwent successful revision surgery using auricular cartilage grafts. Synthetic materials are a useful alternative to autologous tissues during reconstruction of the nasal septum. To our knowledge, we present the largest single-center series of septal reconstructions using unperforated and perforated polydioxanone foils-shown to be useful in the correction of complex septal deformity. However, the unperforated form seems to be associated with a significant risk of postoperative saddling, and we warn against its use in this context. No such complications were observed with the use of thin, 0.15-mm perforated polydioxanone foil, which we exclusively recommend for this application. The use of this implant warrants further evaluation.

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

    Science.gov (United States)

    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. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Performance variation due to stiffness in a tuna-inspired flexible foil model.

    Science.gov (United States)

    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.

  15. The Resource-Saving Technology of Aluminum Nitride Obtaining During Combustion of Aluminum Nanopowder in Air

    OpenAIRE

    Ilyin, Aleksandr Petrovich; Mostovshchikov, Andrey Vladimirovich; Root, Lyudmila Olegovna

    2016-01-01

    The resource-saving technology of aluminum nitride obtaining during the combustion of aluminum nanopowder in air has been analyzed in the article. The investigation of the crystal phases of aluminum nanopowder combustion products obtained under the magnetic field exposure has been made. The experimental results showed the increase of aluminum nitride content up to 86 wt. % in comparison with the aluminum nitride content in combustion products without any exposure. The mechanism of aluminum ni...

  16. Elevated-Temperature Tensile-Testing of Foil-Gage Metals

    Science.gov (United States)

    Blackburn, L. B.; Ellingsworth, J. R.

    1986-01-01

    Automated system for measuring strain in metal foils at temperatures above 500 degrees F (260 degrees C) uses mechanical extensometer and displacement transducer. System includes counterbalance feature, which eliminates weight contribution of extensometer and reduces grip pressure required for attachment to specimen. Counterbalancing feature overcomes two major difficulties in using extensometers with foil-gage specimens: (1) Weight of extensometer and transducer represents significant fraction of total load applied to specimen and may actually damage it; and (2) grip pressure required for attachment of extensometer to specimens may induce bending stresses in foil-gage materials.

  17. Electroplating fission-recoil barriers onto LEU-metal foils for 99Mo-production targets

    International Nuclear Information System (INIS)

    Smaga, J.A.; Sedlet, J.; Conner, C.; Liberatore, M.W.; Walker, D.E.; Wygmans, D.G.; Vandegrift, G.F.

    1997-01-01

    Electroplating experiments on uranium foil have been conducted in order to develop low-enriched uranium composite targets suitable for the production of 99 Mo. Preparation of the foil surface prior to plating was found to play a key role in the quality of the resultant coating. A surface preparation procedure was developed that produces both zinc and nickel coatings with the desired level of coating adherence and coverage. Modifications of the existing plating processes now need investigation to improve to uniformity of the plating thickness, especially at the foil perimeter. (author)

  18. Electroplating fission-recoil barriers onto LEU-metal foils for 99Mo-production targets

    International Nuclear Information System (INIS)

    Smaga, J.A.; Sedlet, J.; Conner, C.; Liberatore, M.W.; Walker, D.E.; Wygmans, D.G.; Vandegrift, G.F.

    1997-10-01

    Electroplating experiments on uranium foil have been conducted in order to develop low-enriched uranium composite targets suitable for the production of 99 Mo. Preparation of the foil surface prior to plating was found to play a key role in the quality of the resultant coating. A surface preparation procedure was developed that produces both zinc and nickel coatings with the desired level of coating adherence and coverage. Modifications of the existing plating processes now need investigation to improve to uniformity of the plating thickness, especially at the foil perimeter

  19. Measurement of the thickness and homogeneity of thin foils by slowing down alpha particles

    International Nuclear Information System (INIS)

    Bimbot, R.; Della Negra, S.; Deprun, C.; Gardes, D.; Rivet, M.F.

    1979-01-01

    The energy loss of 8.785 MeV α particles passing through a thin foil is used to measure the foil thickness. The measurement is performed in various points of the target, the abscissa and ordinate of which are set with precision from the outside of the chamber. This gives a thickness map of the target. The working up of the data, and the use of energy loss tables are made in a standard way. The absolute uncertainty is of some percent for 100 μg/cm 2 foils. The technique has been refined to reach the same precision for 10 μg/cm 2 targets [fr

  20. Real-time x-ray diffraction measurements of shocked polycrystalline tin and aluminum

    Science.gov (United States)

    Morgan, Dane V.; Macy, Don; Stevens, Gerald

    2008-11-01

    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 3×6 mm2 spot and 1° full width half maximum 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 camera through a coherent fiber-optic 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 aluminum lattice with no phase transformation.

  1. Gas evolution behavior of aluminum in mortar

    International Nuclear Information System (INIS)

    Hashizume, Shuji; Matsumoto, Junko; Banba, Tsunetaka

    1996-10-01

    As a part of study of leaching behavior for solidified dry low level radioactive waste, gas evolution behavior of aluminum in mortar was investigated, and a plan of our research was proposed. The effect of pH on corrosion rate of aluminum, corrosion product, time dependency of corrosion rate of aluminum in mortar, change of corrosion mechanism, the effects of Na, Ca and Cl ions on corrosion rate of aluminum in mortar and corrosion behavior of aluminum when aluminum was used as sacrificed anode in reinforced concrete were previously clarified. Study of the effects of environmental factors such as pH, kind of ions and temperature on gas evolution behavior of aluminum and the effect of aluminum/carbon steel surface ratio no gas evolution behavior of aluminum were planed. (author). 75 refs

  2. Gas evolution behavior of aluminum in mortar

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, Shuji; Matsumoto, Junko; Banba, Tsunetaka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-10-01

    As a part of study of leaching behavior for solidified dry low level radioactive waste, gas evolution behavior of aluminum in mortar was investigated, and a plan of our research was proposed. The effect of pH on corrosion rate of aluminum, corrosion product, time dependency of corrosion rate of aluminum in mortar, change of corrosion mechanism, the effects of Na, Ca and Cl ions on corrosion rate of aluminum in mortar and corrosion behavior of aluminum when aluminum was used as sacrificed anode in reinforced concrete were previously clarified. Study of the effects of environmental factors such as pH, kind of ions and temperature on gas evolution behavior of aluminum and the effect of aluminum/carbon steel surface ratio no gas evolution behavior of aluminum were planed. (author). 75 refs.

  3. Tunnelling determined superconducting energy gap of bulk single crystal aluminum

    International Nuclear Information System (INIS)

    Civiak, R.L.

    1974-01-01

    A procedure has been developed for fabricating Giaver tunnel junctions on bulk aluminum. Al-I-Ag junctions were prepared, where I is the naturally formed oxide on the polished, chemically treated aluminum surface. The aluminum energy gap was determined from tunneling conductance curves obtained from samples oriented in three different crystal directions, and as a function of magnetic field in each of these orientations. In contrast to the results of microwave absorption measurements on superconducting aluminum, no magnetic field dependence could be measured for either the average gap or the spread in gap values of the tunneling electrons. This is consistent with commonly accepted tunneling selection rules, and Garfunkel's interpretation of the microwave behavior which depended upon adjusting the energy spectrum of only the electrons traveling parallel to the surface in the presence of a magnetic field. The energy gaps measured for samples oriented in the 100, 110 and 111 directions are 3.52, 3.50 and 3.39 kT/sub c/, respectively. The trend in the anisotropy is the same as in the calculation of Leavens and Carbotte, however, the magnitude of the anisotropy is smaller than in their calculation and that which previous measurements have indicated

  4. The electronic structure of anodized and etched aluminum alloy surfaces

    Science.gov (United States)

    Mullins, W. M.; Averbach, B. L.

    1988-11-01

    Specimens of 6061 and 5052 aluminum alloys which had been anodized and etched by several commonly used procedures were examined by means of bias-reference X-ray photoelectron spectroscopy (XPS). The spectra were compared with those obtained from single crystals of pure aluminum oxides. The chemical shifts observed from the A12p surface oxide lines were interpreted as differences in the Fermi energy levels relative to those in the bulk oxide crystals, and the Fermi energy levels of the surface oxides were thus determined. Using an earlier experimental correlation obtained for values of the point of zero charge (pzc) with Fermi energy levels in aluminum oxide powders, a value of the pzc of the surface oxide was then determined. The surface exhibited the maximum alkalinity, pzc = 8.9, after a caustic etch, and the maximum acidity, pzc = 3.6, after a phosphoric acid anodizing treatment. The significance of these pzc values in the adhesive bonding of aluminum alloys is discussed.

  5. Scaleable Clean Aluminum Melting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Das, S.K. (Secat, Inc.)

    2008-02-15

    The project entitled 'Scaleable Clean Aluminum Melting Systems' was a Cooperative Research and Development Agreements (CRADAs) between Oak Ridge National Laboratory (ORNL) and Secat Inc. The three-year project was initially funded for the first year and was then canceled due to funding cuts at the DOE headquarters. The limited funds allowed the research team to visit industrial sites and investigate the status of using immersion heaters for aluminum melting applications. Primary concepts were proposed on the design of furnaces using immersion heaters for melting. The proposed project can continue if the funding agency resumes the funds to this research. The objective of this project was to develop and demonstrate integrated, retrofitable technologies for clean melting systems for aluminum in both the Metal Casting and integrated aluminum processing industries. The scope focused on immersion heating coupled with metal circulation systems that provide significant opportunity for energy savings as well as reduction of melt loss in the form of dross. The project aimed at the development and integration of technologies that would enable significant reduction in the energy consumption and environmental impacts of melting aluminum through substitution of immersion heating for the conventional radiant burner methods used in reverberatory furnaces. Specifically, the program would couple heater improvements with furnace modeling that would enable cost-effective retrofits to a range of existing furnace sizes, reducing the economic barrier to application.

  6. Chemical synthesis of aluminum nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ghanta, Sekher Reddy; Muralidharan, Krishnamurthi, E-mail: kmsc@uohyd.ernet.in [Advanced Center of Research in High Energy Materials (ACRHEM), University of Hyderabad (India)

    2013-06-15

    An alternate synthetic route has been described for the production of aluminum nanoparticles (Al-NPs). These Al-NPs were obtained through a reduction of aluminum acetylacetonate [Al(acac){sub 3}] by lithium aluminum hydride (LiAlH{sub 4}) in mestitylene at 165 Degree-Sign C. The side products were removed by repeated washing with dry, ice cold methanol and the reaction mixture was filtered to obtain gray-colored Al-NPs. The synthesized nanoparticles were characterized by Powder X-ray diffraction pattern and {sup 27}Al-MAS-NMR spectrum. The X-ray diffraction pattern confirmed the formation of face-centered cubic (fcc) form of aluminum. The size and morphology were investigated by scanning electron microscope and transmission electron microscope which showed particle of varying shapes with size ranging from 50 to 250 nm. The weight loss from the nanoparticles was studied by thermo gravimetric analysis which indicated that the nanoparticles were tightly bound with an unknown amorphous organic residue which cannot be removed by simple washing. The carbonaceous residue might be outcome of the decomposition of acac ligand which was responsible in stabilizing aluminum nanoparticles.

  7. Thermophysical Properties of Liquid Aluminum

    Science.gov (United States)

    Leitner, Matthias; Leitner, Thomas; Schmon, Alexander; Aziz, Kirmanj; Pottlacher, Gernot

    2017-06-01

    Ohmic pulse-heating with sub-microsecond time resolution is used to obtain thermophysical properties for aluminum in the liquid phase. Measurement of current through the sample, voltage drop across the sample, surface radiation, and volume expansion allow the calculation of specific heat capacity and the temperature dependencies of electrical resistivity, enthalpy, and density of the sample at melting and in the liquid phase. Thermal conductivity and thermal diffusivity as a function of temperature are estimated from resistivity data using the Wiedemann-Franz law. Data for liquid aluminum obtained by pulse-heating are quite rare because of the low melting temperature of aluminum with 933.47 K (660.32 °C), as the fast operating pyrometers used for the pulse-heating technique with rise times of about 100 ns generally might not be able to resolve the melting plateau of aluminum because they are not sensitive enough for such low temperature ranges. To overcome this obstacle, we constructed a new, fast pyrometer sensitive in this temperature region. Electromagnetic levitation, as the second experimental approach used, delivers data for surface tension (this quantity is not available by means of the pulse-heating technique) and for density of aluminum as a function of temperature. Data obtained will be extensively compared to existing literature data.

  8. Electronic state alignment, orientation, and coherence produced by beam-foil collisions

    International Nuclear Information System (INIS)

    Church, D.A.

    1975-01-01

    The cylindrically symmetric beam-foil collision produces excitation and alignment of atom and ion levels similar, but not identical, to that resulting at comparable energies from ion-atom or ion-molecule collisions. When the foil is tilted, the macroscopic change acts on the microscopic scale to produce coherent alignment and orientation of the excited levels. The maximum beam energy range bounding this interaction has not yet been defined. The dynamic interaction which produces these effects is currently not predicted by any theory, although the dynamics of the ions subsequent to the collision are well understood. Refinement of current experimental technique can be expected to better define the final foil surface. The beam-tilted-foil collision promises to be useful in the study of ionic structure via quantum beat, radio-frequency and level-crossing spectroscopy techniques, and may provide a useful probe for certain surface interactions. 4 figs, 48 refs

  9. One-step synthesis of TiO₂ nanorod arrays on Ti foil for supercapacitor application.

    Science.gov (United States)

    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.

  10. Modeling the mechanical deformation of nickel foils for nanoimprint lithography on double-curved surfaces

    DEFF Research Database (Denmark)

    Sonne, Mads Rostgaard; Cech, Jiri; Hattel, Jesper Henri

    2013-01-01

    on an aluminium substrate with three different radii; 500 μm, 1000 μm and 2000 μm, respectively. The nano imprint is performed using a 50 μm thick nickel foil, manufactured using electroforming. During the imprinting process, the nickel foil is stretched due to the curved surface of the aluminium substrate....... Experimentally, it is possible to address this stretch by counting the periods of the cross-gratings via SEM characterization. A model for the deformation of the nickel foil during nanoimprint is developed, utilizing non-linear material and geometrical behaviour. Good agreement between measured and numerically...... calculated stretch ratios on the surface of the deformed nickel foil is found, and it is shown, that from the model it is also possible to predict the geometrical extend of the nano-structured area on the curved surfaces....

  11. Self-propelled swimming of a flexible plunging foil near a solid wall.

    Science.gov (United States)

    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.

  12. A free-standing thin foil bolometer for measuring soft x-ray fluence.

    Science.gov (United States)

    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.

  13. Use of Soller slits to remove reference foil fluorescence from transmission spectra.

    Science.gov (United States)

    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.

  14. Ultrathin foils used for low-energy neutral atom imaging of the terrestrial magnetosphere

    International Nuclear Information System (INIS)

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

    1993-01-01

    Magnetospheric imaging by remote detection of low-energy neutral atoms (LENAs) that are created by charge exchange between magnetospheric plasma ions and neutral geocoronal atoms has been proposed as a method to provide global information of magnetospheric dynamics. For LENA detecting, carbon foils can be implemented to (1) ionize the LENAs and electrostatically remove them from the large background of solar UV scattered by the geocorona to which LENA detectors (e.g., microchannel plates) are sensitive and (2) generate secondary electrons to provide coincidence and/or LENA trajectory information. Quantification of LENA-foil interactions are crucial in defining LENA imager performance. The authors present equilibrium charge state distributions due to foil contamination from exposure to air. Angular scattering that results from the projectile-foil interaction is quantified and is shown to be independent of the charge state distribution

  15. Foil Gas Bearing Supported Quiet Fan for Spacecraft Ventilation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Developing a quiet fan for Environmental Control and Life Support systems to enhance the livable environment within the spacecraft has been a challenge. A Foil Gas...

  16. Laser ultrasonic inspection of the microstructural state of thin metal foils.

    Science.gov (United States)

    Balogun, O; Huber, R; Chinn, D; Spicer, J B

    2009-03-01

    A laser-based ultrasonic technique suitable for characterization of the microstructural state of metal foils is presented. The technique relies on the measurement of the intrinsic attenuation of laser-generated longitudinal waves at frequencies reaching 1 GHz resulting from ultrasonic interaction with the sample microstructure. In order to facilitate accurate measurement of the attenuation, a theoretical model-based signal analysis approach is used. The signal analysis approach isolates aspects of the measured attenuation that depend strictly on the microstructure from geometrical effects. Experimental results obtained in commercially cold worked tungsten foils show excellent agreement with theoretical predictions. Furthermore, the experimental results show that the longitudinal wave attenuation at gigahertz frequencies is strongly influenced by the dislocation content of the foils and may find potential application in the characterization of the microstructure of micron thick metal foils.

  17. Effect of liquid uranium on tungsten foils up to 1350/sup 0/C

    Energy Technology Data Exchange (ETDEWEB)

    Kuznietz, M.; Livne, Z.; Cotler, C.; Erez, G.

    1988-11-01

    Immersion experiments have been performed to investigate the effect of liquid uranium on 0.3-mm-thick foils of tungsten metal in the temperature range of 1160 to 1350/sup 0/C, for immersion times up to 20 h, in zirconia crucibles. The original and uranium-reacted foils have been studied microscopically (SEM-EDAX) and the internal morphology has been determined. The latter is affected by the heat-treatment and penetration of liquid uranium. The penetration is partial up to 1210/sup 0/C, accompanied by a partial uranium-assisted recrystallization, forming two metallurgically-different regions, which on cooling result in the observed cracks due to inhomogeneous strain. The penetration of liquid uranium is complete at 1255/sup 0/C and above, inducing recrystallization of tungsten grains throughout the foil, with larger, uranium-lined, grains in inner regions, and smaller, progressively-separated, tungsten grains in outer regions (with reduction in foil thickness).

  18. Progressive dissolution of molybdenum foils in liquid uranium at 1160/sup 0/C

    Energy Technology Data Exchange (ETDEWEB)

    Kuznietz, M.; Cotler, C.

    1988-12-01

    Immersion experiments have been performed to investigate the progressive dissolution of 0.3-mm-thick foils of molybdenum metal in liquid uranium at 1160/sup 0/C, for immersion times of 3, 6, 10, and 60 min, and 20 h, in a zirconia crucible. The original foils, as-received and heat-treated at 1160/sup 0/C, and the uranium-reacted foils have been studied microscopically (SEM-EDAX) and the internal morphology has been determined. The flow lines in as-received molybdenum disappear under heat-treatment, while the undistinguishable grains recrystallize upon heating into grains with average size of 20 m, persisting in samples immersed in liquid uranium. The recrystallization is not uranium-assisted, as uranium does not penetrate into intergranular regions. After incubation time of 3-4 min, outer molybdenum grains dissolve in liquid uranium, thereby reducing the foil thickness progressively. Full dissolution occurs for about 15-min immersion.

  19. An Experimental Investigation into the Temperature Profile of a Compliant Foil Air Bearing

    National Research Council Canada - National Science Library

    Radil, Kevin

    2004-01-01

    A series of tests was performed to determine the internal temperature profile in a compliant bump-type foil journal air bearing operating at room temperature under various speeds and load conditions...

  20. Note: Radial-thrust combo metal mesh foil bearing for microturbomachinery.

    Science.gov (United States)

    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.

  1. Process for forming a nickel foil with controlled and predetermined permeability to hydrogen

    Science.gov (United States)

    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.

  2. Process for forming a nickel foil with controlled and predetermined permeability to hydrogen

    International Nuclear Information System (INIS)

    Engelhaupt, D. E.

    1981-01-01

    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 readilycorrodible nickel anode. The present invention also provides a novel nickel foil having a greater hydrogen permeability than palladium at room temperature

  3. LANL Experience Rolling Zr-Clad LEU-10Mo Foils for AFIP-7

    Energy Technology Data Exchange (ETDEWEB)

    Hammon, Duncan L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clarke, Kester D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alexander, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kennedy, Patrick K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Edwards, Randall L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Duffield, Andrew N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dombrowski, David E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    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.

  4. Magnetic collimation and metal foil filtering for electron range and fluence modulation

    International Nuclear Information System (INIS)

    Phaisangittisakul, N.; D'Souza, W.D.; Ma Lijun

    2004-01-01

    We investigated the use of magnetically collimated electron beams together with metal filters for electron fluence and range modulation. A longitudinal magnetic field collimation method was developed to reduce skin dose and to improve the electron beam penumbra. Thin metal foils were used to adjust the energies of magnetically collimated electrons. The effects for different types of foils such as Al, Be, Cu, Pb, and Ti were studied using Monte Carlo calculations. An empirical pencil beam dose calculation model was developed to calculate electron dose distributions under magnetic collimation and foil modulation. An optimization method was developed to produce conformal dose distributions for simulated targets such as a horseshoe-shaped target. Our results show that it is possible to produce an electron depth dose enhancement peak using similar techniques of producing a spread-out Bragg peak. In conclusion, our study demonstrates new aspects of using magnetic collimation and foil filtration for producing fluence and range modulated electron dose distributions

  5. Intense heavy ion beam-induced temperature effects in carbon-based stripper foils

    International Nuclear Information System (INIS)

    Kupka, K.; Tomut, M.; Simon, P.; Hubert, C.; Romanenko, A.; Lommel, B.; Trautmann, C.

    2015-01-01

    At the future FAIR facility, reliably working solid carbon stripper foils are desired for providing intermediate charge states to SIS18. With the expected high beam intensities, the foils experience enhanced degradation and limited lifetime due to severe radiation damage, stress waves, and thermal effects. This work presents systematic measurements of the temperature of different carbon-based stripper foils (amorphous, diamond-like, and carbon-nanotube based) exposed to 4.8 MeV/u U, Bi, and Au beams of different pulse intensities. Thermal and spectroscopic analyses were performed by means of infrared thermography and Fourier transform infrared spectroscopy. The resulting temperature depends on the foil thickness and strongly increases with increasing pulse intensity and repetition rate. (author)

  6. Interpreting. PEPNet Tipsheet

    Science.gov (United States)

    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…

  7. Engineering Definitional Interpreters

    DEFF Research Database (Denmark)

    Midtgaard, Jan; Ramsay, Norman; Larsen, Bradford

    2013-01-01

    A definitional interpreter should be clear and easy to write, but it may run 4--10 times slower than a well-crafted bytecode interpreter. In a case study focused on implementation choices, we explore ways of making definitional interpreters faster without expending much programming effort. We...

  8. Journalists as Interpretive Communities.

    Science.gov (United States)

    Zelizer, Barbie

    1993-01-01

    Proposes viewing journalists as members of an interpretive community (not a profession) united by its shared discourse and collective interpretations of key public events. Applies the frame of the interpretive community to journalistic discourse about two events central for American journalists--Watergate and McCarthyism. (SR)

  9. Method to Increase Performance of Foil Bearings Through Passive Thermal Management

    Science.gov (United States)

    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

  10. Analysis of polymer foil heaters as infrared radiation sources

    International Nuclear Information System (INIS)

    Witek, Krzysztof; Piotrowski, Tadeusz; Skwarek, Agata

    2012-01-01

    Infrared radiation as a heat source is used in many fields. In particular, the positive effect of far-infrared radiation on living organisms has been observed. This paper presents two technological solutions for infrared heater production using polymer-silver and polymer-carbon pastes screenprinted on foil substrates. The purpose of this work was the identification of polymer layers as a specific frequency range IR radiation sources. The characterization of the heaters was determined mainly by measurement of the surface temperature distribution using a thermovision camera and the spectral characteristics were determined using a special measuring system. Basic parameters obtained for both, polymer silver and polymer carbon heaters were similar and were as follows: power rating of 10–12 W/dm 2 , continuous working surface temperature of 80–90 °C, temperature coefficient of resistance (TCR) about +900 ppm/K for polymer-carbon heater and about +2000 ppm/K for polymer-silver, maximum radiation intensity in the wavelength range of 6–14 μm with top intensity at 8.5 μm and heating time about 20 min. For comparison purposes, commercial panel heater was tested. The results show that the characteristics of infrared polymer heaters are similar to the characteristics of the commercial heater, so they can be taken into consideration as the alternative infrared radiation sources.

  11. Influence of successive plasma treatments on PP foils

    International Nuclear Information System (INIS)

    Jacobs, T; Morent, R; De Geyter, N; Leys, C

    2011-01-01

    Polypropylene (PP) foil is treated with a dielectric barrier discharge (DBD) plasma operating in helium at medium pressure. The influence of exposure to the atmosphere between successive treatments is studied by varying the exposure time. Each PP sample is treated with subsequent treatment steps of 5 s. Between two treatment steps, different procedures are applied: 1) the sample remains in the discharge chamber at medium pressure (under helium atmosphere) for a certain time before it is treated again or 2) the pressure is increased to atmospheric pressure, so the sample remains exposed to atmospheric air for a certain time and afterwards the system is pumped down again to medium pressure before it undergoes a successive helium plasma treatment. The treated samples are analysed using contact angle measurements. The results show that exposure to the atmosphere between two treatment steps leads to a lower contact angle. The longer the exposure time, the lower the contact angle becomes. Another experiment showed that the treatment effect could be gradually removed by applying several short plasma treatments of 1 s to saturated samples. With every short treatment step, the contact angle becomes higher. It is believed that this is due to etching of the surface. In the near future, both atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) analysis on some selected samples are planned to elucidate the chemical and/or physical nature of the observed phenomena.

  12. GEM Foil Quality Assurance For The ALICE TPC Upgrade

    Science.gov (United States)

    Brücken, Erik; Hildén, Timo

    2018-02-01

    The ALICE (A Large Ion Collider Experiment) experiment at the Large Hadron Collider (LHC) at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC) of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2) the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC) -based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz). The new ReadOut Chamber (ROC) design is based on Gas Electron Multiplier (GEM) technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, necessitates thorough Quality Assurance (QA) measures. The QA scheme, developed by the ALICE collaboration, will be presented in detail.

  13. GEM Foil Quality Assurance For The ALICE TPC Upgrade

    Directory of Open Access Journals (Sweden)

    Brücken Erik

    2018-01-01

    Full Text Available The ALICE (A Large Ion Collider Experiment experiment at the Large Hadron Collider (LHC at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2 the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC –based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz. The new ReadOut Chamber (ROC design is based on Gas Electron Multiplier (GEM technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, necessitates thorough Quality Assurance (QA measures. The QA scheme, developed by the ALICE collaboration, will be presented in detail.

  14. Beam foil interaction studies for the future stripper of Ganil

    International Nuclear Information System (INIS)

    Baron, E.; Ricaud, C.

    1988-01-01

    The GANIL 3 - cyclotron accelerator complex is to be upgraded in 1989 by increasing the beam energy at the stripper. In view of this modification, the effect of carbon stripper foils of various thicknesses (from 50 to 250 μg/cm 2 ) on the energy spread of Ar, Kr, Xe and Ta beams was measured using the analysing section of the 270 0 spectrometer. Energies ranging from 3.2 to 6.5 MeV/A (i.e corresponding to the future energy range) were used, and intensities of several hundreds of electrical nanoamperes were concentrated over a few mm 2 spot. Unusually large values of the additional energy spread are reported. In addition, charge state distributions of the 6.48 MeV/A Xe and 4.81 MeV/A Ta beams were measured as a function of the carbon thickness, in order to be able to choose how close to the equilibrium thickness the stripper should be, while keeping the energy spread of the outgoing beams within reasonable limits

  15. A low-mass vacuum exit foil for high energy electrons and hadrons

    International Nuclear Information System (INIS)

    Brand, J.F.J. van den; Kaan, A.P.

    1988-01-01

    The low-mass exit-foil system for the spectrometers in the electron-scattering facility at NIKHEF-K is described. It facilitates the achievement of high momentum resolution as well as the possibility to use the spectrometers for detection of not only protons but also deuterons, tritons, 3 He and 4 He. The system is constructed of very thin Kapton and Mylar foils reinforced with Kevlar material and features a differential pumping system. (orig.)

  16. SU-E-T-25: Real Time Simulator for Designing Electron Dual Scattering Foil Systems.

    Science.gov (United States)

    Carver, R; Hogstrom, K; Price, M; Leblanc, J; Harris, G

    2012-06-01

    To create a user friendly, accurate, real time computer simulator to facilitate the design of dual foil scattering systems for electron beams on radiotherapy accelerators. The simulator should allow for a relatively quick, initial design that can be refined and verified with subsequent Monte Carlo (MC) calculations and measurements. The simulator consists of an analytical algorithm for calculating electron fluence and a graphical user interface (GUI) C++ program. The algorithm predicts electron fluence using Fermi-Eyges multiple Coulomb scattering theory with a refined Moliere formalism for scattering powers. The simulator also estimates central-axis x-ray dose contamination from the dual foil system. Once the geometry of the beamline is specified, the simulator allows the user to continuously vary primary scattering foil material and thickness, secondary scattering foil material and Gaussian shape (thickness and sigma), and beam energy. The beam profile and x-ray contamination are displayed in real time. The simulator was tuned by comparison of off-axis electron fluence profiles with those calculated using EGSnrc MC. Over the energy range 7-20 MeV and using present foils on the Elekta radiotherapy accelerator, the simulator profiles agreed to within 2% of MC profiles from within 20 cm of the central axis. The x-ray contamination predictions matched measured data to within 0.6%. The calculation time was approximately 100 ms using a single processor, which allows for real-time variation of foil parameters using sliding bars. A real time dual scattering foil system simulator has been developed. The tool has been useful in a project to redesign an electron dual scattering foil system for one of our radiotherapy accelerators. The simulator has also been useful as an instructional tool for our medical physics graduate students. © 2012 American Association of Physicists in Medicine.

  17. High quality graphene synthesized by atmospheric pressure CVD on copper foil

    OpenAIRE

    Trinsoutrot, Pierre; Rabot, Caroline; Vergnes, Hugues; Delamoreanu, Alexandru; Zenasni, Aziz; Caussat, Brigitte

    2013-01-01

    International audience; Graphene was synthesized at 1000 °C by Atmospheric Pressure Chemical Vapor Deposition on copper foil from methane diluted in argon and hydrogen. The influence of the main synthesis parameters was studied on 2 × 2 cm2 foils in order to obtain continuous monolayer graphenewithout crystalline defect. The uniformity, crystal quality and number of layers of graphenewere analyzed by Raman spectroscopy and Scanning Electronic Microscopy. First, an increase of the annealing pr...

  18. Models of printed boards for solderless mounting of electronic components by foil perforation method

    Directory of Open Access Journals (Sweden)

    Yefimenko A. A.

    2017-10-01

    Full Text Available The paper presents models of printed circuit boards for an improved foil perforation method. The density of electrical connections of such printed circuit boards is estimated in comparison with circuit boards obtained using the methods of mounting in holes and surface mounting. The technological differences in the manufacture of printed circuit boards for the foil perforation method and the traditional method are considered.

  19. Measurements of Sound Velocity of Laser-Irradiated Iron Foils Relevant to Earth Core Condition

    International Nuclear Information System (INIS)

    Shigemori, K.; Ichinose, D.; Otani, K.; Shiota, T.; Sakaiya, T.; Azechi, H.; Irifune, T.

    2006-01-01

    We have developed a novel method to measure sound velocity of laser-irradiated iron foils by side-on x-ray radiograph technique. Iron foils were irradiated with two-stepped laser pulse to reach the earth's core condition. We obtained not only the sound velocity but also temperature, pressure, shock velocity, compressibility, and particle velocity of the laser-irradiated iron. The experimental results are in good agreements with previous experimental results and with one-dimensional simulation results

  20. Production of hydrogen in the reaction between aluminum and water in the presence of NaOH and KOH

    Directory of Open Access Journals (Sweden)

    C. B. Porciúncula

    2012-06-01

    Full Text Available The objective of this work is to investigate the production of hydrogen as an energy source by means of the reaction of aluminum with water. This reaction only occurs in the presence of NaOH and KOH, which behave as catalysts. The main advantages of using aluminum for indirect energy storage are: recyclability, non-toxicity and easiness to shape. Alkali concentrations varying from 1 to 3 mol.L-1 were applied to different metallic samples, either foil (0.02 mm thick or plates (0.5 and 1 mm thick, and reaction temperatures between 295 and 345 K were tested. The results show that the reaction is strongly influenced by temperature, alkali concentration and metal shape. NaOH commonly promotes faster reactions and higher real yields than KOH.

  1. Solid-state 27Al nuclear magnetic resonance investigation of three aluminum-centered dyes

    KAUST Repository

    Mroué, Kamal H.

    2010-02-01

    We report the first solid-state 27Al NMR study of three aluminum phthalocyanine dyes: aluminum phthalocyanine chloride, AlPcCl (1); aluminum-1,8,15,22-tetrakis(phenylthio)-29H,31H-phthalocyanine chloride, AlPc(SPh)4Cl (2); and aluminum-2,3-naphthalocyanine chloride, AlNcCl (3). Each of these compounds contains Al3+ ions coordinating to four nitrogen atoms and a chlorine atom. Solid-state 27Al NMR spectra, including multiple-quantum magic-angle spinning (MQMAS) spectra and quadrupolar Carr-Purcell-Meiboom-Gill (QCPMG) spectra of stationary powdered samples have been acquired at multiple high magnetic field strengths (11.7, 14.1, and 21.1 T) to determine their composition and number of aluminum sites, which were analyzed to extract detailed information on the aluminum electric field gradient (EFG) and nuclear magnetic shielding tensors. The quadrupolar parameters for each 27Al site were determined from spectral simulations, with quadrupolar coupling constants (CQ) ranging from 5.40 to 10.0 MHz and asymmetry parameters (η) ranging from 0.10 to 0.50, and compared well with the results of quantum chemical calculations of these tensors. We also report the largest 27Al chemical shielding anisotropy (CSA), with a span of 120 ± 10 ppm, observed directly in a solid material. The combination of MQMAS and computational predictions are used to interpret the presence of multiple aluminum sites in two of the three samples.

  2. Spin-polarized radioactive isotope beam produced by tilted-foil technique

    International Nuclear Information System (INIS)

    Hirayama, Yoshikazu; Mihara, Mototsugu; Watanabe, Yutaka; Jeong, Sun-Chan; Miyatake, Hiroari; Momota, Sadao; Hashimoto, Takashi; Imai, Nobuaki; Matsuta, Kensaku; Ishiyama, Hironobu; Ichikawa, Shin-ichi; Ishii, Tetsuro; Izumikawa, Takuji; Katayama, Ichiro; Kawakami, Hirokane; Kawamura, Hirokazu; Nishinaka, Ichiro; Nishio, Katsuhisa; Makii, Hiroyuki; Mitsuoka, Shin-ichi

    2013-01-01

    Highlights: • Detail study for tilted foil technique. • New equation for estimating nuclear polarization dependence on the beam energy. • Production of nuclear polarization for heaviest nucleus 123 In in ground state. -- Abstract: The tilted-foil method for producing spin-polarized radioactive isotope beams has been studied using the re-accelerated radioactive 8 Li and 123 In beams produced at Tokai Radioactive Ion Accelerator Complex (TRIAC) facility. We successfully produced polarization in a 8 Li beam of 7.3(5)% using thin polystyrene foils (4.2 μg/cm 2 ). The systematic study of the nuclear polarization as a function of the number of foils and beam energy has been performed, confirming the features of the tilted-foil technique experimentally. After the study, a spin-polarized radioactive 123 In beam, which is the heaviest ever polarized in its ground state by this method, has been successfully generated by the tilted-foil method, for the nuclear spectroscopy around the doubly magic nucleus 132 Sn

  3. A Systems Approach to the Solid Lubrication of Foil Air Bearings for Oil-Free Turbomachinery

    Science.gov (United States)

    DellaCorte, Christopher; Zaldana, Antonio R.; Radil, Kevin C.

    2002-01-01

    Foil air bearings are self-acting hydrodynamic bearings which rely upon solid lubricants to reduce friction and minimize wear during sliding which occurs at start-up and shut-down when surface speeds are too low to allow the formation of a hydrodynamic air film. This solid lubrication is typically accomplished by coating the non-moving foil surface with a thin, soft polymeric film. The following paper introduces a systems approach in which the solid lubrication is provided by a combination of self lubricating shaft coatings coupled with various wear resistant and lubricating foil coatings. The use of multiple materials, each providing different functions is modeled after oil-lubricated hydrodynamic sleeve bearing technology which utilizes various coatings and surface treatments in conjunction with oil lubricants to achieve optimum performance. In this study, room temperature load capacity tests are performed on journal foil air bearings operating at 14,000 rpm. Different shaft and foil coating technologies such as plasma sprayed composites, ceramic, polymer and inorganic lubricant coatings are evaluated as foil bearing lubricants. The results indicate that bearing performance is improved through the individual use of the lubricants and treatments tested. Further, combining several solid lubricants together yielded synergistically better results than any material alone.

  4. Alpha Oscillations during Incidental Encoding Predict Subsequent Memory for New "Foil" Information.

    Science.gov (United States)

    Vogelsang, David A; Gruber, Matthias; Bergström, Zara M; Ranganath, Charan; Simons, Jon S

    2018-01-11

    People can employ adaptive strategies to increase the likelihood that previously encoded information will be successfully retrieved. One such strategy is to constrain retrieval toward relevant information by reimplementing the neurocognitive processes that were engaged during encoding. Using EEG, we examined the temporal dynamics with which constraining retrieval toward semantic versus nonsemantic information affects the processing of new "foil" information encountered during a memory test. Time-frequency analysis of EEG data acquired during an initial study phase revealed that semantic compared with nonsemantic processing was associated with alpha decreases in a left frontal electrode cluster from around 600 msec after stimulus onset. Successful encoding of semantic versus nonsemantic foils during a subsequent memory test was related to decreases in alpha oscillatory activity in the same left frontal electrode cluster, which emerged relatively late in the trial at around 1000-1600 msec after stimulus onset. Across participants, left frontal alpha power elicited by semantic processing during the study phase correlated significantly with left frontal alpha power associated with semantic foil encoding during the memory test. Furthermore, larger left frontal alpha power decreases elicited by semantic foil encoding during the memory test predicted better subsequent semantic foil recognition in an additional surprise foil memory test, although this effect did not reach significance. These findings indicate that constraining retrieval toward semantic information involves reimplementing semantic encoding operations that are mediated by alpha oscillations and that such reimplementation occurs at a late stage of memory retrieval, perhaps reflecting additional monitoring processes.

  5. Foil Strain Gauges Using Piezoresistive Carbon Nanotube Yarn: Fabrication and Calibration.

    Science.gov (United States)

    Abot, Jandro L; Góngora-Rubio, Mário R; Anike, Jude C; Kiyono, César Y; Mello, Luis A M; Cardoso, Valtemar F; Rosa, Reinaldo L S; Kuebler, Derek A; Brodeur, Grace E; Alotaibi, Amani H; Coene, Marisa P; Coene, Lauren M; Jean, Elizabeth; Santiago, Rafael C; Oliveira, Francisco H A; Rangel, Ricardo; Thomas, Gilles P; Belay, Kalayu; da Silva, Luciana W; Moura, Rafael T; Seabra, Antonio C; Silva, Emílio C N

    2018-02-05

    Carbon nanotube yarns are micron-scale fibers comprised by tens of thousands of carbon nanotubes in their cross section and exhibiting piezoresistive characteristics that can be tapped to sense strain. This paper presents the details of novel foil strain gauge sensor configurations comprising carbon nanotube yarn as the piezoresistive sensing element. The foil strain gauge sensors are designed using the results of parametric studies that maximize the sensitivity of the sensors to mechanical loading. The fabrication details of the strain gauge sensors that exhibit the highest sensitivity, based on the modeling results, are described including the materials and procedures used in the first prototypes. Details of the calibration of the foil strain gauge sensors are also provided and discussed in the context of their electromechanical characterization when bonded to metallic specimens. This characterization included studying their response under monotonic and cyclic mechanical loading. It was shown that these foil strain gauge sensors comprising carbon nanotube yarn are sensitive enough to capture strain and can replicate the loading and unloading cycles. It was also observed that the loading rate affects their piezoresistive response and that the gauge factors were all above one order of magnitude higher than those of typical metallic foil strain gauges. Based on these calibration results on the initial sensor configurations, new foil strain gauge configurations will be designed and fabricated, to increase the strain gauge factors even more.

  6. PENGEMBANGAN FOIL NACA SERI 2412 SEBAGAI SISTEM PENYELAMAN MODEL KAPAL SELAM

    Directory of Open Access Journals (Sweden)

    Ali Munazid

    2015-06-01

    Full Text Available Bentuk  foil menghasilkan gaya angkat (lift force ketika foil dilewati oleh aliran fluida  karena adanya pengaruh interaksi antara aliran fluida dengan permukaan foil yang mengakibatkan tekanan permukaan atas lebih kecil dari permukaan bawah. Bagaimana mengaplikasikan teori foil pada hydroplane kapal selam sebagai  system penyelaman, dengan membalik foil maka lift force tersebut menjadi gaya ke bawah, dengan demikian memungkinkan kapal selam dapat menyelam, melayang dan bermanouver di bawah air, seperti halnya gerak pesawat terbang yang terbang dan melayang dengan menggunakan sayap. Dilakukan penelitian dan pengamatan terhadap kemampuan penyelaman (diving plan dari foil NACA seri 2412 pada model kapal selam, dengan mencari nilai Cl (coefisien lift di Laboratorium, serta mendesain bentuk badan kapal selam dan analisa gaya-gaya yang bekerja pada model kapal selam, jumlah gaya-gaya yang bekerja keatas lebih rendah dari gaya-gaya ke bawah maka kapal selam mampu menyelam. Penerapan Hydroplane sebagai diving plane dapat diterapkan, kemampuan penyelaman dipengaruhi oleh sudut flip  Hydroplane dan kecepatan model, semakin besar kecepatan dan sudut flip maka semakin besar kedalaman penyelaman yang dapat dilakukan.

  7. Foil Strain Gauges Using Piezoresistive Carbon Nanotube Yarn: Fabrication and Calibration

    Directory of Open Access Journals (Sweden)

    Jandro L. Abot

    2018-02-01

    Full Text Available Carbon nanotube yarns are micron-scale fibers comprised by tens of thousands of carbon nanotubes in their cross section and exhibiting piezoresistive characteristics that can be tapped to sense strain. This paper presents the details of novel foil strain gauge sensor configurations comprising carbon nanotube yarn as the piezoresistive sensing element. The foil strain gauge sensors are designed using the results of parametric studies that maximize the sensitivity of the sensors to mechanical loading. The fabrication details of the strain gauge sensors that exhibit the highest sensitivity, based on the modeling results, are described including the materials and procedures used in the first prototypes. Details of the calibration of the foil strain gauge sensors are also provided and discussed in the context of their electromechanical characterization when bonded to metallic specimens. This characterization included studying their response under monotonic and cyclic mechanical loading. It was shown that these foil strain gauge sensors comprising carbon nanotube yarn are sensitive enough to capture strain and can replicate the loading and unloading cycles. It was also observed that the loading rate affects their piezoresistive response and that the gauge factors were all above one order of magnitude higher than those of typical metallic foil strain gauges. Based on these calibration results on the initial sensor configurations, new foil strain gauge configurations will be designed and fabricated, to increase the strain gauge factors even more.

  8. Foil Strain Gauges Using Piezoresistive Carbon Nanotube Yarn: Fabrication and Calibration

    Science.gov (United States)

    Góngora-Rubio, Mário R.; Kiyono, César Y.; Mello, Luis A. M.; Cardoso, Valtemar F.; Rosa, Reinaldo L. S.; Kuebler, Derek A.; Brodeur, Grace E.; Alotaibi, Amani H.; Coene, Marisa P.; Coene, Lauren M.; Jean, Elizabeth; Santiago, Rafael C.; Oliveira, Francisco H. A.; Rangel, Ricardo; Thomas, Gilles P.; Belay, Kalayu; da Silva, Luciana W.; Moura, Rafael T.; Seabra, Antonio C.; Silva, Emílio C. N.

    2018-01-01

    Carbon nanotube yarns are micron-scale fibers comprised by tens of thousands of carbon nanotubes in their cross section and exhibiting piezoresistive characteristics that can be tapped to sense strain. This paper presents the details of novel foil strain gauge sensor configurations comprising carbon nanotube yarn as the piezoresistive sensing element. The foil strain gauge sensors are designed using the results of parametric studies that maximize the sensitivity of the sensors to mechanical loading. The fabrication details of the strain gauge sensors that exhibit the highest sensitivity, based on the modeling results, are described including the materials and procedures used in the first prototypes. Details of the calibration of the foil strain gauge sensors are also provided and discussed in the context of their electromechanical characterization when bonded to metallic specimens. This characterization included studying their response under monotonic and cyclic mechanical loading. It was shown that these foil strain gauge sensors comprising carbon nanotube yarn are sensitive enough to capture strain and can replicate the loading and unloading cycles. It was also observed that the loading rate affects their piezoresistive response and that the gauge factors were all above one order of magnitude higher than those of typical metallic foil strain gauges. Based on these calibration results on the initial sensor configurations, new foil strain gauge configurations will be designed and fabricated, to increase the strain gauge factors even more. PMID:29401745

  9. Numerical simulation of the pressure pulses produced by a pressure screen foil rotor

    International Nuclear Information System (INIS)

    Feng, M.; Ollivier-Gooch, C.; Gooding, R.W.; Olson, J.A.

    2003-01-01

    Pressure screening is the most industrially efficient and effective means of removing contaminants that degrade the appearance and strength of paper and fractionating fibres for selective treatments and specialty products. A critical design component of a screen is the rotor which produces pressure pulses on the screen cylinder surface to keep the screening apertures clear. To understand the effect of the key design and operating variables for a NACA 0012 foil rotor, a computational fluid dynamic (CFD) simulation tool was developed with FLUENT software, and the numerical results were compared with experimental measurements. The computational results of pressure pulses were shown to be in good agreement with experimental pressure measurements over a wide range of foil tip-speeds, clearances and angles of attack. In addition, it was shown that the magnitude of the pressure pulse peak increases as the rotating speed increases linearly with the square of tip-speed for all the angles of attack studied. The maximum negative pressure pulse occurred for the foil at 5 degrees angle of attack. Flow began to separate from foil surface near the screen plate beyond 10 degrees angle of attack. The positive pressure peak near the leading edge of the foil is completely eliminated for foils operating at a positive angle of attack. The magnitude of the negative pressure peak increased as clearance decreased. In addition to, and more important than, these specific results, we have shown that CFD is a viable tool for the optimal design and operation of rotors in industrial pressure screens. (author)

  10. Development and Application of Integrated Aerodynamic Protuberant Foil Journal and Thrust Bearing in Turboexpander

    Directory of Open Access Journals (Sweden)

    Tianwei Lai

    2017-01-01

    Full Text Available Foil bearing provides compliant support and moderate Coulomb friction for rotor-bearing system, which is conducive to stability and reliability of high speed rotating machinery. In this paper, both hydrodynamic lubricated foil journal and foil thrust bearings are applied in a 150 m3·h−1 turboexpander for air separation. In the bearings, protuberant foil is chosen as the supporting subfoil due to its merits of easy fabrication and assembly. Static loading and deflection of the bearings are tested, respectively, before integration into the turboexpander. Afterwards, the loading and deflection curves of the journal and thrust bearings are polynomial fitted using least-square method. Then, performance tests are carried out on the rotor-bearing system, including transient speed-up, high speed, and speed-down processes. In the tests, the turboexpander supported by the hydrodynamic foil bearings operates smoothly with repeatability. Maximal rotor speed of the turboexpander reaches 52000 rpm with hydrodynamic lubricated protuberant foil bearings.

  11. A foil stripper and terminal steering assembly for an FN tandem

    International Nuclear Information System (INIS)

    Weitkamp, W.G.

    1989-01-01

    The authors report how they recently installed a new foil stripper mechanism and steerer assembly in their FN tandem terminal. The project had the following goals: To significantly increase the number of foils in the tandem. The authors formerly had only a 38 foil capacity. Now that the new superconducting booster is running, demand for foils has increased drastically. To add horizontal steering plates to the vertical steering plates in the terminal. With conventional HVEC inclined field beam tubes, the position of the beam at the exit of the tandem is sensitive to the variation in value of the column resistors. Minor beam tube misalignments can also cause the beam to come out displaced horizontally by an annoying amount. To retain the gas stripper tube. The authors occasionally find it convenient to use gas stripping for low energy heavy ion beams and for ions for which the foil consumption rate is excessive. To electrically insulate all terminal components so the terminal ripple remover will continue to operate. The terminal ripple remover, which is designed to reduce beam energy fluctuations, places a rapidly varying 2-9 kV bias on the stripper foil or stripper gas canal in response to an energy correction signal derived from the image slits. The energy correction signal is transmitted optically to the terminal

  12. Aluminum nitride insulating films for MOSFET devices

    Science.gov (United States)

    Lewicki, G. W.; Maserjian, J.

    1972-01-01

    Application of aluminum nitrides as electrical insulator for electric capacitors is discussed. Electrical properties of aluminum nitrides are analyzed and specific use with field effect transistors is defined. Operational limits of field effect transistors are developed.

  13. Aluminum--Industry of the Future

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-01-23

    This 8-page brochure describes the Office of Industrial Technologies' Aluminum Industry of the Future; a partnership between the Department of Energy and the aluminum industry established to increase industrial energy and cost efficiency.

  14. Aluminum-carbon composite electrode

    Science.gov (United States)

    Farahmandi, C.J.; Dispennette, J.M.

    1998-07-07

    A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg. 3 figs.

  15. Aluminum-air battery crystallizer

    Science.gov (United States)

    Maimoni, A.

    1987-01-01

    A prototype crystallizer system for the aluminum-air battery operated reliably through simulated startup and shutdown cycles and met its design objectives. The crystallizer system allows for crystallization and removal of the aluminium hydroxide reaction product; it is required to allow steady-state and long-term operation of the aluminum-air battery. The system has to minimize volume and maintain low turbulence and shear to minimize secondary nucleation and energy consumption while enhancing agglomeration. A lamella crystallizer satisfies system constraints.

  16. Aluminum-carbon composite electrode

    Science.gov (United States)

    Farahmandi, C. Joseph; Dispennette, John M.

    1998-07-07

    A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

  17. The effect of zinc on the aluminum anode of the aluminum-air battery

    Science.gov (United States)

    Tang, Yougen; Lu, Lingbin; Roesky, Herbert W.; Wang, Laiwen; Huang, Baiyun

    Aluminum is an ideal material for batteries, due to its excellent electrochemical performance. Herein, the effect of zinc on the aluminum anode of the aluminum-air battery, as an additive for aluminum alloy and electrolytes, has been studied. The results show that zinc can decrease the anodic polarization, restrain the hydrogen evolution and increase the anodic utilization rate.

  18. 75 FR 70689 - Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum-Greenwood Forge Division; Currently...

    Science.gov (United States)

    2010-11-18

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-70,376] Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum- Greenwood Forge Division; Currently Known As Contech Forgings, LLC..., applicable to workers of Kaiser Aluminum Fabricated Products, LLC, Kaiser Aluminum-Greenwood Forge Division...

  19. Synthesis and Processing of Nanocrystalline Aluminum Nitride

    OpenAIRE

    Duarte, Matthew Albert

    2016-01-01

    Synthesis, processing and characterization of nanocrystalline aluminum nitride has been systematically studied. Non-carbon based gas nitridation was used to reduce nanocrystalline γ-alumina, having a grain size of ~80 nm. Single phase aluminum nitride powder was obtained at firing temperatures of 1200°C. Further processing of AlN powders was performed by CAPAD (Current Activated Pressure Assisted Densification) to obtain dense single phase aluminum nitride. Dense bulk aluminum nitride was ob...

  20. Mineral resource of the month: aluminum

    Science.gov (United States)

    Bray, E. Lee

    2012-01-01

    The article offers information on aluminum, a mineral resource which is described as the third-most abundant element in Earth's crust. According to the article, aluminum is the second-most used metal. Hans Christian Oersted, a Danish chemist, was the first to isolate aluminum in the laboratory. Aluminum is described as lightweight, corrosion-resistant and an excellent conductor of electricity and heat.

  1. Recycling of Aluminum from Fibre Metal Laminates

    NARCIS (Netherlands)

    Zhu, G.; Xiao, Y.; Yang, Y.; Wang, J.; Sun, B.; Boom, R.

    2012-01-01

    Recycling of aluminum alloy scrap obtained from delaminated fibre metal laminates (FMLs) was studied through high temperature refining in the presence of a salt flux. The aluminum alloy scrap contains approximately mass fraction w(Cu) = 4.4%, w(Mg) = 1.1% and w(Mn) = 0.6% (2024 aluminum alloy). The

  2. 21 CFR 182.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  3. 75 FR 80527 - Aluminum Extrusions From China

    Science.gov (United States)

    2010-12-22

    ...)] Aluminum Extrusions From China AGENCY: United States International Trade Commission. ACTION: Scheduling of... of subsidized and less-than-fair-value imports from China of aluminum extrusions, primarily provided... contained in Aluminum Extrusions From the People's Republic of China: Notice of Preliminary Determination of...

  4. 21 CFR 73.2645 - Aluminum powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements of...

  5. 21 CFR 582.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  6. 21 CFR 172.310 - Aluminum nicotinate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum nicotinate. 172.310 Section 172.310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Special Dietary and Nutritional Additives § 172.310 Aluminum nicotinate. Aluminum nicotinate may be safely...

  7. Measurements by activation foils and comparative computations by MCNP code

    International Nuclear Information System (INIS)

    Kyncl, J.

    2008-01-01

    Systematic study of the radioactive waste minimisation problem is subject of the SPHINX project. Its idea is that burning or transmutation of the waste inventory problematic part will be realized in a nuclear reactor the fuel of which is in the form of liquid fluorides. In frame of the project, several experiments have been performed with so-called inserted experimental channel. The channel was filled up by the fluorides mixture, surrounded by six fuel assemblies with moderator and placed into LR-0 reactor vessel. This formation was brought to critical state and measurement with activation foil detectors were carried out at selected positions of the inserted channel. Main aim of the measurements was to determine reaction rates for the detectors mentioned. For experiment evaluation, comparative computations were accomplished by code MCNP4a. The results obtained show that very often, computed values of reaction rates differ substantially from the values that were obtained from the experiment. This contribution deals with analysis of the reasons of these differences from the point of view of computations by Monte Carlo method. The analysis of concrete cases shows that the inaccuracy of reaction rate computed is caused mostly by three circumstances:-space region that is occupied by detector is relatively very small;- microscopic effective cross-section R(E) of the reaction changes strongly with energy just in the energy interval that gives the greatest contribution to the reaction; - in the energy interval that gives the greatest contribution to reaction rate, the error of the computed neutron flux is great. These circumstances evoke that the computation of reaction rate with casual accuracy submits extreme demands on computing time. (Author)

  8. Characterization of ultrafine aluminum nanoparticles

    International Nuclear Information System (INIS)

    Sandstrom, Mary M.; Jorgensen, Betty S.; Mang, Joseph T.; Smith, Bettina L.; Son, Steven F.

    2004-01-01

    Aluminum nanopowders with particle sizes ranging from ∼25 nm to 80 nm were characterized by a variety of methods. We present and compare the results from common powder characterization techniques including transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), BET gas adsorption surface area analysis, thermogravimetric analysis (TGA), photon correlation spectroscopy (PCS), and low angle laser light scattering (LALLS). Aluminum nanoparticles consist of an aluminum core with an aluminum oxide coating. HRTEM measurements of both the particle diameter and oxide layer thickness tend to be larger than those obtained from BET and TGA. LALLS measurements show a large degree of particle agglomeration in solution; therefore, primary particle sizes could not be determined. Furthermore, results from small-angle scattering techniques (SAS), including small-angle neutron (SANS) and x-ray (SAXS) scattering are presented and show excellent agreement with the BET, TGA, and HRTEM. The suite of analytical techniques presented in this paper can be used as a powerful tool in the characterization of many types of nanosized powders.

  9. Aluminum: The Next Twenty Years

    Science.gov (United States)

    Fitzgerald, M. Desmond; Pollio, Gerald

    1982-12-01

    This report concludes that the outlook for the world aluminum industry is quite favorable. Demand is expected to expand at a more rapid rate than for other basic metals, but not sufficiently to put undue strain on productive capacity. Capital requirements of the world aluminum industry are projected at 95.5 billion in 1980 prices — more than 200 billion in current prices—over the balance of the century. Given the aluminum industry's past success in generating internal funds, this level of capital expanditure should not cause undue financing problems. Finally, we expect changes to occur in the structure of the industry over the forecast period, with virtually all new alumina capacity being installed in proximity to bauxite production, and—with the exception of Australia—a major shift in smelting capacity away from other industrialized economies. While the large multinational companies will still play a dominant role in the world aluminum market, their share of production and ownership is likely to decline progressively during the period.

  10. Luminescent properties of aluminum hydride

    Energy Technology Data Exchange (ETDEWEB)

    Baraban, A.P.; Gabis, I.E.; Dmitriev, V.A. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation); Dobrotvorskii, M.A., E-mail: mstislavd@gmail.com [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation); Kuznetsov, V.G. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation); Matveeva, O.P. [National Mineral Resources University, Saint Petersburg 199106 (Russian Federation); Titov, S.A. [Petersburg State University of Railway Transport, Saint-Petersburg 190031 (Russian Federation); Voyt, A.P.; Elets, D.I. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation)

    2015-10-15

    We studied cathodoluminescence and photoluminescence of α-AlH{sub 3}– a likely candidate for use as possible hydrogen carrier in hydrogen-fueled vehicles. Luminescence properties of original α-AlH{sub 3} and α-AlH{sub 3} irradiated with ultraviolet were compared. The latter procedure leads to activation of thermal decomposition of α-AlH{sub 3} and thus has a practical implementation. We showed that the original and UV-modified aluminum hydride contain luminescence centers ‐ structural defects of the same type, presumably hydrogen vacancies, characterized by a single set of characteristic bands of radiation. The observed luminescence is the result of radiative intracenter relaxation of the luminescence center (hydrogen vacancy) excited by electrons or photons, and its intensity is defined by the concentration of vacancies, and the area of their possible excitation. UV-activation of the dehydrogenation process of aluminum hydride leads to changes in the spatial distribution of the luminescence centers. For short times of exposure their concentration increases mainly in the surface regions of the crystals. At high exposures, this process extends to the bulk of the aluminum hydride and ends with a decrease in concentration of luminescence centers in the surface region. - Highlights: • Aluminum hydride contains hydrogen vacancies which serve as luminescence centers. • The luminescence is the result of radiative relaxation of excited centers. • Hydride UV-irradiation alters distribution and concentration of luminescence centers.

  11. Recrystallization in Commercially Pure Aluminum

    DEFF Research Database (Denmark)

    Bay, Bent; Hansen, Niels

    1984-01-01

    Recrystallization behavior in commercial aluminum with a purity of 99.4 pct was studied by techniques such as high voltage electron microscopy, 100 kV transmission electron microscopy, and light microscopy. Sample parameters were the initial grain size (290 and 24 microns) and the degree of defor...

  12. Aluminum break-point contacts

    NARCIS (Netherlands)

    Heinemann, Martina; Groot, R.A. de

    1997-01-01

    Ab initio molecular dynamics is used to study the contribution of a single Al atom to an aluminum breakpoint contact during the final stages of breaking and the initial stages of the formation of such a contact. A hysteresis effect is found in excellent agreement with experiment and the form of the

  13. Directly polished lightweight aluminum mirror

    Science.gov (United States)

    ter Horst, Rik; Tromp, Niels; de Haan, Menno; Navarro, Ramon; Venema, Lars; Pragt, Johan

    2017-11-01

    During the last ten years, Astron has been a major contractor for the design and manufacturing of astronomical instruments for Space- and Earth based observatories, such as VISIR, MIDI, SPIFFI, X-Shooter and MIRI. Driven by the need to reduce the weight of optically ultra-stiff structures, two promising techniques have been developed in the last years: ASTRON Extreme Lightweighting [1][2] for mechanical structures and an improved Polishing Technique for Aluminum Mirrors. Using one single material for both optical components and mechanical structure simplifies the design of a cryogenic instrument significantly, it is very beneficial during instrument test and verification, and makes the instrument insensitive to temperature changes. Aluminum has been the main material used for cryogenic optical instruments, and optical aluminum mirrors are generally diamond turned. The application of a polishable hard top coating like nickel removes excess stray light caused by the groove pattern, but limits the degree of lightweighting of the mirrors due to the bi-metal effect. By directly polishing the aluminum mirror surface, the recent developments at Astron allow for using a non-exotic material for light weighted yet accurate optical mirrors, with a lower surface roughness ( 1nm RMS), higher surface accuracy and reduced light scattering. This paper presents the techniques, obtained results and a global comparison with alternative lightweight mirror solutions. Recent discussions indicate possible extensions of the extreme light weight technology to alternative materials such as Zerodur or Silicon Carbide.

  14. Intense heavy ion beam-induced effects in carbon-based stripper foils

    Energy Technology Data Exchange (ETDEWEB)

    Kupka, Katharina

    2016-08-15

    Amorphous carbon or carbon-based stripper foils are commonly applied in accelerator technology for electron stripping of ions. At the planned facility for antiproton and ion research (FAIR) at the Helmholtzzentrum fuer Schwerionenforschung (GSI), Darmstadt, thin carbon stripper foils provide an option for directly delivering ions of intermediate charge states to the heavy ion synchrotron, SIS 18, in order to mitigate space charge limitations during high-intensity operation. In case of desired high end-energies in the synchrotron, a second stripping process by a thicker carbon foil provides ions of higher charge states for injection into the SIS18. High beam intensities and a pulsed beam structure as foreseen at FAIR pose new challenges to the stripper foils which experience enhanced degradation by radiation damage, thermal effects, and stress waves. In order to ensure reliable accelerator operation, radiation-hard stripper foils are required. This thesis aims to a better understanding of processes leading to degradation of carbon-based thin foils. Special focus is placed on ion-beam induced structure and physical property changes and on the influence of different beam parameters. Irradiation experiments were performed at the M3-beamline of the universal linear accelerator (UNILAC) at GSI, using swift heavy ion beams with different pulse lengths and repetition rates. Tested carbon foils were standard amorphous carbon stripper foils produced by the GSI target laboratory, as well as commercial amorphous and diamond-like carbon foils and buckypaper foils. Microstructural changes were investigated with various methods such as optical microscopy, scanning electron microscopy (SEM), profilometry and chromatic aberration measurements. For the investigation of structural changes X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), in-situ Fourier-transform infrared spectroscopy (FTIR) and small angle X

  15. Intense heavy ion beam-induced effects in carbon-based stripper foils

    International Nuclear Information System (INIS)

    Kupka, Katharina

    2016-08-01

    Amorphous carbon or carbon-based stripper foils are commonly applied in accelerator technology for electron stripping of ions. At the planned facility for antiproton and ion research (FAIR) at the Helmholtzzentrum fuer Schwerionenforschung (GSI), Darmstadt, thin carbon stripper foils provide an option for directly delivering ions of intermediate charge states to the heavy ion synchrotron, SIS 18, in order to mitigate space charge limitations during high-intensity operation. In case of desired high end-energies in the synchrotron, a second stripping process by a thicker carbon foil provides ions of higher charge states for injection into the SIS18. High beam intensities and a pulsed beam structure as foreseen at FAIR pose new challenges to the stripper foils which experience enhanced degradation by radiation damage, thermal effects, and stress waves. In order to ensure reliable accelerator operation, radiation-hard stripper foils are required. This thesis aims to a better understanding of processes leading to degradation of carbon-based thin foils. Special focus is placed on ion-beam induced structure and physical property changes and on the influence of different beam parameters. Irradiation experiments were performed at the M3-beamline of the universal linear accelerator (UNILAC) at GSI, using swift heavy ion beams with different pulse lengths and repetition rates. Tested carbon foils were standard amorphous carbon stripper foils produced by the GSI target laboratory, as well as commercial amorphous and diamond-like carbon foils and buckypaper foils. Microstructural changes were investigated with various methods such as optical microscopy, scanning electron microscopy (SEM), profilometry and chromatic aberration measurements. For the investigation of structural changes X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), in-situ Fourier-transform infrared spectroscopy (FTIR) and small angle X

  16. Genre and Interpretation

    DEFF Research Database (Denmark)

    Auken, Sune

    2015-01-01

    Despite the immensity of genre studies as well as studies in interpretation, our understanding of the relationship between genre and interpretation is sketchy at best. The article attempts to unravel some of intricacies of that relationship through an analysis of the generic interpretation carried...... out by us all in everyday life, and the role of generic interpretation in scholarly work. The article argues that the role played by genre in interpretation has as much to do with the individual characteristics of an utterance as with its relationship to other utterances. An interest in the generic...... traits of an utterance will lead to a characterization of its individual, as well as its general characteristics. The article proceeds to describe three central concepts within genre studies that are applicable to generic interpretation: “horizon of expectation,” “world,” and the triad “theme...

  17. On court interpreters' visibility

    DEFF Research Database (Denmark)

    Dubslaff, Friedel; Martinsen, Bodil

    in by the participants almost immediately after the interrogations and supplemented by interviews. The main objective of the project is to explore the interpreters' own perception of the quality of the service they render as well as the professional users´ and the other language users' perception of the quality...... of the service they receive. Ultimately, the findings will be used for training purposes. Future - and, for that matter, already practising - interpreters as well as the professional users of interpreters ought to take the reality of the interpreters' work in practice into account when assessing the quality......, such as the interpreter's engagement in explicit co-construction of meaning. In addition, we shall include social factors which must be assumed to have a bearing on the interpreter's behaviour. Here we can, at least to some extent, draw upon the questionnaires and interviews mentioned above. Finally, we shall discuss...

  18. Interpreting land records

    CERN Document Server

    Wilson, Donald A

    2014-01-01

    Base retracement on solid research and historically accurate interpretation Interpreting Land Records is the industry's most complete guide to researching and understanding the historical records germane to land surveying. Coverage includes boundary retracement and the primary considerations during new boundary establishment, as well as an introduction to historical records and guidance on effective research and interpretation. This new edition includes a new chapter titled "Researching Land Records," and advice on overcoming common research problems and insight into alternative resources wh

  19. Monoenergetic ion beams from ultrathin foils irradiated by ultrahigh-contrast circularly polarized laser pulses

    Directory of Open Access Journals (Sweden)

    O. Klimo

    2008-03-01

    Full Text Available Acceleration of ions from ultrathin foils irradiated by intense circularly polarized laser pulses is investigated using one- and two-dimensional particle simulations. A circularly polarized laser wave heats the electrons much less efficiently than the wave of linear polarization and the ion acceleration process takes place on the front side of the foil. The ballistic evolution of the foil becomes important after all ions contained in the foil have been accelerated. In the ongoing acceleration process, the whole foil is accelerated as a dense compact bunch of quasineutral plasma implying that the energy spectrum of ions is quasimonoenergetic. Because of the ballistic evolution, the velocity spread of an accelerated ion beam is conserved while the average velocity of ions may be further increased. This offers the possibility to control the parameters of the accelerated ion beam. The ion acceleration process is described by the momentum transfer from the laser beam to the foil and it might be fairly efficient in terms of the energy transferred to the heavy ions even if the foil contains a comparable number of light ions or some surface contaminants. Two-dimensional simulations confirm the formation of the quasimonoenergetic spectrum of ions and relatively good collimation of the ion bunch, however the spatial distribution of the laser intensity poses constraints on the maximum velocity of the ion beam. The present ion acceleration mechanism might be suitable for obtaining a dense high energy beam of quasimonoenergetic heavy ions which can be subsequently applied in nuclear physics experiments. Our simulations are complemented by a simple theoretical model which provides the insights on how to control the energy, number, and energy spread of accelerated ions.

  20. Annealing of (DU-10Mo)-Zr Co-Rolled Foils

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Robin Montoya [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alexander, David John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mccabe, Rodney James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clarke, Kester Diederik [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scott, Jeffrey E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montalvo, Joel Dwayne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Papin, Pallas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ansell, George S. [Colorado School of Mines, Golden, CO (United States)

    2017-01-20

    Producing uranium-10wt% molybdenum (DU-10Mo) foils to clad with Al first requires initial bonding of the DU-10Mo foil to zirconium (Zr) by hot rolling, followed by cold rolling to final thickness. Rolling often produces wavy (DU-10Mo)-Zr foils that should be flattened before further processing, as any distortions could affect the final alignment and bonding of the Al cladding to the Zr co-rolled surface layer; this bonding is achieved by a hot isostatic pressing (HIP) process. Distortions in the (DU-10Mo)-Zr foil may cause the fuel foil to press against the Al cladding and thus create thinner or thicker areas in the Al cladding layer during the HIP cycle. Post machining is difficult and risky at this stage in the process since there is a chance of hitting the DU-10Mo. Therefore, it is very important to establish a process to flatten and remove any waviness. This study was conducted to determine if a simple annealing treatment could flatten wavy foils. Using the same starting material (i.e. DU-10Mo coupons of the same thickness), five different levels of hot rolling and cold rolling, combined with five different annealing treatments, were performed to determine the effect of these processing variables on flatness, bonding of layers, annealing response, microstructure, and hardness. The same final thickness was reached in all cases. Micrographs, textures, and hardness measurements were obtained for the various processing combinations. Based on these results, it was concluded that annealing at 650°C or higher is an effective treatment to appreciably reduce foil waviness.

  1. Relationship between heating atmosphere and copper foil impurities during graphene growth via low pressure chemical vapor deposition

    OpenAIRE

    Çelik, Yasemin; Escoffier, Walter; Yang, Ming; Flahaut, Emmanuel; Suvacı, Ender

    2016-01-01

    International audience; Low-pressure chemical vapor deposition synthesis of graphene films on two different Cu foils, with different surface oxygen and carbon contents, was performed by controlling H2 and/or Ar flow rates during heating. The influences of heating atmosphere on the final impurity level, quality of the synthesized graphene films and thickness uniformity were investigated depending on Cu foil impurities. Heating of carbon-rich, but oxygen-poor Cu foil in H2 environment resulted ...

  2. Decarbonization process for carbothermically produced aluminum

    Science.gov (United States)

    Bruno, Marshall J.; Carkin, Gerald E.; DeYoung, David H.; Dunlap, Sr., Ronald M.

    2015-06-30

    A method of recovering aluminum is provided. An alloy melt having Al.sub.4C.sub.3 and aluminum is provided. This mixture is cooled and then a sufficient amount of a finely dispersed gas is added to the alloy melt at a temperature of about 700.degree. C. to about 900.degree. C. The aluminum recovered is a decarbonized carbothermically produced aluminum where the step of adding a sufficient amount of the finely dispersed gas effects separation of the aluminum from the Al.sub.4C.sub.3 precipitates by flotation, resulting in two phases with the Al.sub.4C.sub.3 precipitates being the upper layer and the decarbonized aluminum being the lower layer. The aluminum is then recovered from the Al.sub.4C.sub.3 precipitates through decanting.

  3. Nanodiamond Foils for H- Stripping to Support the Spallation Neutron Source (SNS) and Related Applications

    Energy Technology Data Exchange (ETDEWEB)

    Vispute, R D [Blue Wave Semiconductors; Ermer, Henry K [Blue Wave Semiconductors; Sinsky, Phillip [Blue Wave Semiconductors; Seiser, Andrew [Blue Wave Semiconductors; Shaw, Robert W [ORNL; Wilson, Leslie L [ORNL; Harris, Gary [Howard University; Piazza, Fabrice [Pontifica Universidad Catolica Madre y Maestra, Dominican Republic

    2013-01-01

    Thin diamond foils are needed in many particle accelerator experiments regarding nuclear and atomic physics, as well as in some interdisciplinary research. Particularly, nanodiamond texture is attractive for this purpose as it possesses a unique combination of diamond properties such as high thermal conductivity, mechanical strength and high radiation hardness; therefore, it is a potential material for energetic ion beam stripper foils. At the ORNL Spallation Neutron Source (SNS), the installed set of foils must be able to survive a nominal five-month operation period, without the need for unscheduled costly shutdowns and repairs. Thus, a single nanodiamond foil about the size of a postage stamp is critical to the entire operation of SNS and similar sources in U.S. laboratories and around the world. We are investigating nanocrystalline, polycrystalline and their admixture films fabricated using a hot filament chemical vapor deposition (HFCVD) system for H- stripping to support the SNS at Oak Ridge National Laboratory. Here we discuss optimization of process variables such as substrate temperature, process gas ratio of H2/Ar/CH4, substrate to filament distance, filament temperature, carburization conditions, and filament geometry to achieve high purity diamond foils on patterned silicon substrates with manageable intrinsic and thermal stresses so that they can be released as free standing foils without curling. An in situ laser reflectance interferometry tool (LRI) is used for monitoring the growth characteristics of the diamond thin film materials. The optimization process has yielded free standing foils with no pinholes. The sp3/sp2 bonds are controlled to optimize electrical resistivity to reduce the possibility of surface charging of the foils. The integrated LRI and HFCVD process provides real time information on the growth of films and can quickly illustrate growth features and control over film thickness. The results are discussed in the light of development

  4. Linguistics in Text Interpretation

    DEFF Research Database (Denmark)

    Togeby, Ole

    2011-01-01

    A model for how text interpretation proceeds from what is pronounced, through what is said to what is comunicated, and definition of the concepts 'presupposition' and 'implicature'.......A model for how text interpretation proceeds from what is pronounced, through what is said to what is comunicated, and definition of the concepts 'presupposition' and 'implicature'....

  5. Acquiring specific interpreting competence

    Directory of Open Access Journals (Sweden)

    Jana Zidar Forte

    2012-12-01

    Full Text Available In postgraduate interpreter training, the main objective of the course is to help trainees develop various competences, from linguistic, textual and cultural competence, to professional and specific interpreting competence. For simultaneous interpreting (SI, the main focus is on mastering the SI technique and strategies as well as on developing and strengthening communicative skills, which is discussed and illustrated with examples in the present paper. First, a brief overview is given of all the necessary competences of a professional interpreter with greater emphasis on specific interpreting competence for SI. In the second part of the paper, various approaches are described in terms of acquiring specific skills and strategies, specifically through a range of exercises. Besides interpreting entire speeches, practical courses should also consist of targeted exercises, which help trainees develop suitable coping strategies and mechanisms (later on almost automatisms, while at the same time "force" them to reflect on their individual learning process and interpreting performance. This provides a solid base on which trained interpreters can progress and develop their skills also after joining the professional sphere.

  6. Life Cycle Interpretation

    DEFF Research Database (Denmark)

    Bonou, Alexandra; Olsen, Stig Irving

    2017-01-01

    an interpretation. The process of interpretation starts with identification of potentially significant issues in the previous stages of goal and scope definition, inventory analysis and impact assessment, and examples of potential significant issues are given for each phase. The significance is then determined...

  7. Spectroscopic Measurements of Planar Foil Plasmas Driven by a MA LTD

    Science.gov (United States)

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

    2014-10-01

    Planar foil ablation experiments are being conducted on the Linear Transformer Driver (LTD) at the University of Michigan. The experiment consists of a 400 nm-thick, Al planar foil and a current return post. An optical fiber is placed perpendicular to the magnetic field and linear polarizers are used to isolate the pi and sigma lines. The LTD is charged to +/-70 kV with approximately 400-500 kA passing through the foil. Laser shadowgraphy has previously imaged the plasma and measured anisotropy in the Magneto Rayleigh-Taylor (MRT) instability. Localized magnetic field measurements using Zeeman splitting during the current rise is expected to yield some insight into this anisotropy. Initial experiments use Na D lines of Al foils seeded with sodium to measure Zeeman splitting. Several ion lines are also currently being studied, such as Al III and C IV, to probe the higher temperature core plasma. In planned experiments, several lens-coupled optical fibers will be placed across the foil, and local magnetic field measurements will be taken to measure current division within the plasma. 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.

  8. Aluminium foil as an alternative substrate for the spectroscopic interrogation of endometrial cancer.

    Science.gov (United States)

    Paraskevaidi, Maria; Morais, Camilo L M; Raglan, Olivia; Lima, Kássio M G; Paraskevaidis, Evangelos; Martin-Hirsch, Pierre L; Kyrgiou, Maria; Martin, Francis L

    2018-03-07

    Biospectroscopy has the potential to investigate and characterise biological samples and could, therefore, be utilised to diagnose various diseases in a clinical environment. An important consideration in spectrochemical studies is the cost-effectiveness of the substrate used to support the sample, as high expense would limit their translation into clinic. In this paper, the performance of low-cost aluminium (Al) foil substrates was compared with the commonly used low-emissivity (low-E) slides. Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy was used to analyse blood plasma and serum samples from women with endometrial cancer and healthy controls. The two populations were differentiated using principal component analysis with support vector machines (PCA-SVM) with 100% sensitivity in plasma samples (endometrial cancer=70; healthy controls=15) using both Al foil and low-E slides as substrates. The same sensitivity results (100%) were achieved for serum samples (endometrial cancer=60; healthy controls=15). Specificity was found higher using Al foil (90%) in comparison to low-E slides (85%) and lower using Al foil (70%) in comparison to low-E slides in serum samples. The establishment of Al foil as low-cost and highly-performing substrate would pave the way for large-scale, multi-centre studies and potentially for routine clinical use. This article is protected by copyright. All rights reserved.

  9. A New Analysis Tool Assessment for Rotordynamic Modeling of Gas Foil Bearings

    Science.gov (United States)

    Howard, Samuel A.; SanAndres, Luis

    2010-01-01

    Gas foil bearings offer several advantages over traditional bearing types that make them attractive for use in high-speed turbomachinery. They can operate at very high temperatures, require no lubrication supply (oil pumps, seals, etc.), exhibit very long life with no maintenance, and once operating airborne, have very low power loss. The use of gas foil bearings in high-speed turbomachinery has been accelerating in recent years, although the pace has been slow. One of the contributing factors to the slow growth has been a lack of analysis tools, benchmarked to measurements, to predict gas foil bearing behavior in rotating machinery. To address this shortcoming, NASA Glenn Research Center (GRC) has supported the development of analytical tools to predict gas foil bearing performance. One of the codes has the capability to predict rotordynamic coefficients, power loss, film thickness, structural deformation, and more. The current paper presents an assessment of the predictive capability of the code, named XLGFBTH (Texas A&M University). A test rig at GRC is used as a simulated case study to compare rotordynamic analysis using output from the code to actual rotor response as measured in the test rig. The test rig rotor is supported on two gas foil journal bearings manufactured at GRC, with all pertinent geometry disclosed. The resulting comparison shows that the rotordynamic coefficients calculated using XLGFBTH represent the dynamics of the system reasonably well, especially as they pertain to predicting critical speeds.

  10. Surface structure deduced differences of copper foil and film for graphene CVD growth

    International Nuclear Information System (INIS)

    Tian, Junjun; Hu, Baoshan; Wei, Zidong; Jin, Yan; Luo, Zhengtang; Xia, Meirong; Pan, Qingjiang; Liu, Yunling

    2014-01-01

    Highlights: • We demonstrate the significant differences between Cu foil and film in the surface morphology and crystal orientation distribution. • The different surface structure leads to the distinctive influences of the CH 4 and H 2 concentrations on the thickness and quality of as-grown graphene. • Nucleation densities and growth rate differences at the initial growth stages on the Cu foil and film were investigated and discussed. - Abstract: Graphene was synthesized on Cu foil and film by atmospheric pressure chemical vapor deposition (CVD) with CH 4 as carbon source. Electron backscattered scattering diffraction (EBSD) characterization demonstrates that the Cu foil surface after the H 2 -assisted pre-annealing was almost composed of Cu(1 0 0) crystal facet with larger grain size of ∼100 μm; meanwhile, the Cu film surface involved a variety of crystal facets of Cu(1 1 1), Cu(1 0 0), and Cu(1 1 0), with the relatively small grain size of ∼10 μm. The different surface structure led to the distinctive influences of the CH 4 and H 2 concentrations on the thickness and quality of as-grown graphene. Further data demonstrate that the Cu foil enabled more nucleation densities and faster growth rates at the initial growth stages than the Cu film. Our results are beneficial for understanding the relationship between the metal surface structure and graphene CVD growth

  11. The Chevron Foil Thrust Bearing: Improved Performance Through Passive Thermal Management and Effective Lubricant Mixing

    Science.gov (United States)

    Bruckner, Robert

    2013-01-01

    An improved foil thrust bearing is described that eliminates or reduces the need for forced cooling of the bearing foils while at the same time improves the load capacity of the bearing, enhances damping, provides overload tolerance, and eliminates the high speed load capacity drop-off that plagues the current state of the art. The performance improvement demonstrated by the chevron foil thrust bearing stems from a novel trailing edge shape that splays the hot lubricant in the thin film radially, thus preventing hot lubricant carry-over into the ensuing bearing sector. Additionally, the chevron shaped trailing edge induces vortical mixing of the hot lubricant with the gas that is naturally resident within the inter-pad region of a foil thrust bearing. The elimination of hot gas carry-over in combination with the enhanced mixing has enabled a completely passive thermally managed foil bearing design. Laboratory testing at NASA has confirmed the original analysis and reduced this concept to practice.

  12. Simultaneous schlieren photography and soot foil in the study of detonation phenomena

    Science.gov (United States)

    Kellenberger, Mark; Ciccarelli, Gaby

    2017-10-01

    The use of schlieren photography has been essential in unravelling the complex nature of high-speed combustion phenomena, but its line-of-sight integration makes it difficult to decisively determine the nature of multi-dimensional combustion wave propagation. Conventional schlieren alone makes it impossible to determine in what plane across the channel an observed structure may exist. To overcome this, a technique of simultaneous high-speed schlieren photography and soot foils was demonstrated that can be applied to the study of detonation phenomena. Using a kerosene lamp, soot was deposited on a glass substrate resulting in a semi-transparent sheet through which schlieren source light could pass. In order to demonstrate the technique, experiments were carried out in mixtures of stoichiometric hydrogen-oxygen at initial pressures between 10 and 15 kPa. Compared to schlieren imaging obtained without a sooted foil, high-speed video results show schlieren images with a small reduction of contrast with density gradients remaining clear. Areas of high temperature cause soot lofted from the foil to incandescence strongly, resulting in the ability to track hot spots and flame location. Post-processing adjustments were demonstrated to make up for camera sensitivity limitations to enable viewing of schlieren density gradients. High-resolution glass soot foils were produced that enable direct coupling of schlieren video to triple-point trajectories seen on the soot foils, allowing for the study of three-dimensional propagation mechanisms of detonation waves.

  13. Diffusion of liquid uranium into solid tantalum foils up to 1350C

    Energy Technology Data Exchange (ETDEWEB)

    Kuznietz, M.; Livne, Z.; Cotler, C.

    1986-01-01

    The diffusion of liquid uranium into solid foils, 0.3 mm thick, was investigated in the temperature range 1160-1350C, for reaction times up to 20 h. The tantalum foils were immersed in liquid uranium contained in zirconia crucibles. Uranium was found to cover the tantalum foils and climb upwards in amounts rising with reaction time and temperature. A scanning electron microscope study with microanalysis by EDAX revealed a multilayer structure. On the tantalum-foil surfaces, exposed to liquid uranium, layers form progressively inwards, under the outer uranium layers, in the following sequence: a uranium-tantalum layer (with a U:Ta ratio between 40:60 and 60:40) forms at 1160 C and 1185 C, and disappears completely at 1255 C; a columnar tantalum layer (containing <1W/O U); an inner uranium layer (at 1210 C and above); an inner tantalum-grain layer with uranium along grain boundaries (above 1210 C). The growth of the recrystallized columnar tantalum layer is related to the penetration of uranium as liquid into the solid tantalum foil. Cracks in this layer at 1300 C and above cause tears and failures in the tantalum.

  14. An Oil-Free Thrust Foil Bearing Facility Design, Calibration, and Operation

    Science.gov (United States)

    Bauman, Steve

    2005-01-01

    New testing capabilities are needed in order to foster thrust foil air bearing technology development and aid its transition into future Oil-Free gas turbines. This paper describes a new test apparatus capable of testing thrust foil air bearings up to 100 mm in diameter at speeds to 80,000 rpm and temperatures to 650 C (1200 F). Measured parameters include bearing torque, load capacity, and bearing temperatures. This data will be used for design performance evaluations and for validation of foil bearing models. Preliminary test results demonstrate that the rig is capable of testing thrust foil air bearings under a wide range of conditions which are anticipated in future Oil-Free gas turbines. Torque as a function of speed and temperature corroborates results expected from rudimentary performance models. A number of bearings were intentionally failed with no resultant damage whatsoever to the test rig. Several test conditions (specific speeds and loads) revealed undesirable axial shaft vibrations which have been attributed to the magnetic bearing control system and are under study. Based upon these preliminary results, this test rig will be a valuable tool for thrust foil bearing research, parametric studies and technology development.

  15. UV Ink-Jet printability and durability of stone and foil

    Directory of Open Access Journals (Sweden)

    Tadeja Muck

    2014-07-01

    Full Text Available he use of ultraviolet (UV printing technology has impacted printing industry in last years due to its applicability on many different »absorptive« as well as »non-absorptive« printing materials. The printability of building materials and recycled foils is relatively unknown. For primary building materials like stones, functionality can be explored with the use of UV printing technology; increased visual, informative effect or even “creative printing” of buildings. Also several aspects of recycled foils reusability as a printing material could be find (printed packaging material or also like secondary building materials. In the present study, printability of the stone and recycled foil and durability of UV prints was explored by means of macroscopically and microscopically characterization. Results indicate that higher print quality can be achieved on polished stone and on coated foil, which surfaces have higher smoothness. Durability of UV prints at freezing is higher at unpolished stone and coated foil that is at materials with the higher surface energy.

  16. Experiments on helical modes in magnetized thin foil-plasmas

    Science.gov (United States)

    Yager-Elorriaga, David

    2017-10-01

    This paper gives an in-depth experimental study of helical features on magnetized, ultrathin foil-plasmas driven by the 1-MA linear transformer driver at University of Michigan. Three types of cylindrical liner loads were designed to produce: (a) pure magneto-hydrodynamic (MHD) modes (defined as being void of the acceleration-driven magneto-Rayleigh-Taylor instability, MRT) using a non-imploding geometry, (b) pure kink modes using a non-imploding, kink-seeded geometry, and (c) MRT-MHD coupled modes in an unseeded, imploding geometry. For each configuration, we applied relatively small axial magnetic fields of Bz = 0.2-2.0 T (compared to peak azimuthal fields of 30-40 T). The resulting liner-plasmas and instabilities were imaged using 12-frame laser shadowgraphy and visible self-emission on a fast framing camera. The azimuthal mode number was carefully identified with a tracking algorithm of self-emission minima. Our experiments show that the helical structures are a manifestation of discrete eigenmodes. The pitch angle of the helix is simply m / kR , from implosion to explosion, where m, k, and R are the azimuthal mode number, axial wavenumber, and radius of the helical instability. Thus, the pitch angle increases (decreases) during implosion (explosion) as R becomes smaller (larger). We found that there are one, or at most two, discrete helical modes that arise for magnetized liners, with no apparent threshold on the applied Bz for the appearance of helical modes; increasing the axial magnetic field from zero to 0.5 T changes the relative weight between the m = 0 and m = 1 modes. Further increasing the applied axial magnetic fields yield higher m modes. Finally, the seeded kink instability overwhelms the intrinsic instability modes of the plasma. These results are corroborated with our analytic theory on the effects of radial acceleration on the classical sausage, kink, and higher m modes. Work supported by US DOE award DE-SC0012328, Sandia National Laboratories

  17. The dissimilar brazing of Kovar alloy to SiCp/Al composites using silver-based filler metal foil

    Science.gov (United States)

    Wang, Peng; Xu, Dongxia; Zhai, Yahong; Niu, Jitai

    2017-09-01

    Aluminum metal matrix composites with high SiC content (60 vol.% SiCp/Al MMCs) were surface metallized with a Ni-P alloy coating, and vacuum brazing between the composites and Kovar alloy were performed using rapidly cooled Ag-22.0Cu-15.9In-10.86Sn-1.84Ti (wt%) foil. The effects of Ni-P alloy coating and brazing parameters on the joint microstructures and properties were researched by SEM, EDS, and single lap shear test, respectively. Results show that Ag-Al intermetallic strips were formed in the 6063Al matrix and filler metal layer because of diffusion, and they were arranged regularly and accumulated gradually as the brazing temperature was increased ( T/°C = 550-600) or the soaking time was prolonged ( t/min = 10-50). However, excessive strips would destroy the uniformity of seams and lead to a reduced bonding strength (at most 70 MPa). Using a Ni-P alloy coating, void free joints without those strips were obtained at 560 °C after 20 min soaking time, and a higher shear strength of 90 MPa was achieved. The appropriate interface reaction ( 2 μm transition layer) that occurred along the Ni-P alloy coating/filler metal/Kovar alloy interfaces resulted in better metallurgical bonding. In this research, the developed Ag-based filler metal was suitable for brazing the dissimilar materials of Ni-P alloy-coated SiCp/Al MMCs and Kovar alloy, and capable welding parameters were also broadened.

  18. Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range

    International Nuclear Information System (INIS)

    Vidovic, Z.

    1997-06-01

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H 0 , H 2 + and H 3 + projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H 2 + and H 3 + polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

  19. The Resource-Saving Technology of Aluminum Nitride Obtaining During Combustion of Aluminum Nanopowder in Air

    Directory of Open Access Journals (Sweden)

    Ilyin Alexander

    2016-01-01

    Full Text Available The resource-saving technology of aluminum nitride obtaining during the combustion of aluminum nanopowder in air has been analyzed in the article. The investigation of the crystal phases of aluminum nanopowder combustion products obtained under the magnetic field exposure has been made. The experimental results showed the increase of aluminum nitride content up to 86 wt. % in comparison with the aluminum nitride content in combustion products without any exposure. The mechanism of aluminum nitride formation and stabilization in air was due to the oxygen molecules deactivation by light emission during combustion.

  20. Origin of 6-fold coordinated aluminum at (010-type pyrophyllite edges

    Directory of Open Access Journals (Sweden)

    M. Okumura

    2017-05-01

    Full Text Available To better understand the aqueous chemical reactivity of clay mineral edges we explored the relationships between hydration and the structure of (010-type edges of pyrophyllite. In particular, we used density functional theory and the quantum theory of atoms in molecules to evaluate the stability of 6-fold coordinated hydrated aluminum at the edge in terms of the electron density distribution. Geometrical optimization revealed an intra-edge hydrogen bond network between aluminol hydroxyls and water ligands completing the aluminum coordination shell. From the electron density isosurfaces one water ligand is not covalently bonded to aluminum. Bader charge analysis revealed that OH2 ligands have small negative charge. In addition, it is also found that the charge of the 6-fold coordinated aluminum is larger than one of the 5-fold aluminum. From these results, the charging of the OH2 ligands is interpreted as charge transfer originated from the formation of the hydrogen bond network and not from Al-OH2 interaction per se. This suggests that the weakly bound water ligand in question, and more generally 6-fold hydrated edge Al coordination, is stabilized primarily by the hydrogen bond network which in turn leads to weak ionic attraction to the aluminum center itself. The finding highlights the importance of cooperative effects between solvent structure and the coordination of metal cations exposed at clay mineral edges.

  1. Electrically Conductive Anodized Aluminum Surfaces

    Science.gov (United States)

    Nguyen, Trung Hung

    2006-01-01

    Anodized aluminum components can be treated to make them sufficiently electrically conductive to suppress discharges of static electricity. The treatment was conceived as a means of preventing static electric discharges on exterior satin-anodized aluminum (SAA) surfaces of spacecraft without adversely affecting the thermal-control/optical properties of the SAA and without need to apply electrically conductive paints, which eventually peel off in the harsh environment of outer space. The treatment can also be used to impart electrical conductivity to anodized housings of computers, medical electronic instruments, telephoneexchange equipment, and other terrestrial electronic equipment vulnerable to electrostatic discharge. The electrical resistivity of a typical anodized aluminum surface layer lies between 10(exp 11) and 10(exp 13) Omega-cm. To suppress electrostatic discharge, it is necessary to reduce the electrical resistivity significantly - preferably to surface becomes covered and the pores in the surface filled with a transparent, electrically conductive metal oxide nanocomposite. Filling the pores with the nanocomposite reduces the transverse electrical resistivity and, in the original intended outer-space application, the exterior covering portion of the nanocomposite would afford the requisite electrical contact with the outer-space plasma. The electrical resistivity of the nanocomposite can be tailored to a value between 10(exp 7) and 10(exp 12) Omega-cm. Unlike electrically conductive paint, the nanocomposite becomes an integral part of the anodized aluminum substrate, without need for adhesive bonding material and without risk of subsequent peeling. The electrodeposition process is compatible with commercial anodizing production lines. At present, the electronics industry uses expensive, exotic, electrostaticdischarge- suppressing finishes: examples include silver impregnated anodized, black electroless nickel, black chrome, and black copper. In

  2. The Synthesis of Highly Aligned Cupric Oxide Nanowires by Heating Copper Foil

    Directory of Open Access Journals (Sweden)

    Jianbo Liang

    2011-01-01

    Full Text Available We have investigated the effects of grain size and orientation of copper substrates for the growth of cupric oxide nanowires by thermal oxidation method. Long, less-roughness, high-density, and aligned cupric oxide nanowires have been synthesized by heating (200 oriented copper foils with small grain size in air gas. Long and aligned nanowires of diameter around 80 nm can only be formed within a short temperature range from 400 to 700°C. On the other hand, uniform, smooth-surface, and aligned nanowires were not formed in the case of larger crystallite size of copper foils with (111 and (200 orientation. Smaller grain size of copper foil with (200 orientation is favorable for the growth of highly aligned, smooth surface, and larger-diameter nanowires by thermal oxidation method.

  3. Experimental study on mass transfer of contaminants through an enthalpy recovery unit with polymer membrane foils

    DEFF Research Database (Denmark)

    Nie, Jinzhe; Fang, Lei

    2014-01-01

    Laboratory experimental studies were conducted to investigate the mass transfer of contaminants through a total heat recovery unit with polymer membranes foils. The studies were conducted in twin climate chambers which simulated outdoor and indoor thermal climates. One manufacturd total heat...... recovery unit with polymer membrane foils was used as refeering unit in this study. The experiments were conducted with different outdoor thermal climates e.g. warm-humid and cold-dry climates; isothermal and non isothermal as well as equal humidity and non equal humidity with indoor climate. Three...... membrane or due to both reasons. The results indicated that polymer membrane foils may be a choice for producing total heat recovering equipment in ventilation systems....

  4. A new flexible titanium foil cell for hydrothermal experiments and fluid sampling.

    Science.gov (United States)

    Wu, Shi-Jun; Cai, Min-Jian; Yang, Can-Jun; Li, Ke-Wei

    2016-09-01

    This paper describes the design of a flexible titanium foil cell, as well as its applications in hydrothermal experiments and in non-contaminating storage of seafloor hydrothermal fluids. A flexible cell constructed totally from pure titanium (Grade 1) can be used in corrosive environment because of the excellent chemical stability and temperature tolerance of the material. Theoretical calculation and finite element analysis of the titanium foil cell have been conducted to identify its flexibility and deformation mode. Two applications, i.e., hydrothermal reaction and non-contaminating fluid sampling, were introduced subsequently. The flexible titanium foil cell was successfully tested at elevated temperature and pressure of up to 400 °C and 40 MPa, respectively, demonstrating that it could be widely used under supercritical water conditions.

  5. Applications of beam-foil spectroscopy to atomic collisions in solids

    Science.gov (United States)

    Sellin, I. A.

    1976-01-01

    Some selected papers presented at the Fourth International Conference on Beam-Foil Spectroscopy, whose results are of particular pertinence to ionic collision phenomena in solids, are reviewed. The topics discussed include solid target effects and means of surmounting them in the measurement of excited projectile ion lifetimes for low-energy heavy element ions; the electron emission accompanying the passage of heavy particles through solid targets; the collision broadening of X rays emitted from 100 keV ions moving in solids; residual K-shell excitation in chlorine ions penetrating carbon; comparison between 40 MeV Si on gaseous SiH4 targets at 300 mtorr and 40 MeV Si on Al; and the emergent surface interaction in beam-foil spectroscopy. A distinct overlap of interests between the sciences of beam-foil spectroscopy and atomic collisions in solids is pointed out.

  6. Resonance effects of transition radiation emitted from thin foil stacks using electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Awata, Takaaki; Yajima, Kazuaki; Tanaka, Takashi [Kyoto Univ. (Japan). Faculty of Engineering] [and others

    1997-03-01

    Transition Radiation(TR) X rays are expected to be a high brilliant X-ray source because the interference among TR X rays emitted from many thin foils placed periodically in vacuum can increase their intensity and make them quasi-monochromatic. In order to study the interference (resonance) effects of TR, we measured the energy spectra of TR for several sets of thin-foil stacks at various emission angles. It was found that the resonance effects of TR are classified into intrafoil and interfoil resonances and the intensity of TR X rays increases nonlinearly with increasing foil number, attributing to the interfoil resonance. It became evident that the brilliance of TR is as high as that of SR. (author)

  7. X-ray scattering measurements from thin-foil x-ray mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; BYRNAK, BP; Hornstrup, Allan

    1992-01-01

    Thin foil X-ray mirrors are to be used as the reflecting elements in the telescopes of the X-ray satellites Spectrum-X-Gamma (SRG) and ASTRO-D. High resolution X-ray scattering measurements from the Au coated and dip-lacquered Al foils are presented. These were obtained from SRG mirrors positioned...... in a test quadrant of the telescope structure and from ASTRO-D foils held in a simple fixture. The X-ray data is compared with laser data and other surface structure data such as STM, atomic force microscopy (AFM), TEM, and electron micrography. The data obtained at Cu K-alpha(1), (8.05 keV) from all...

  8. Bright betatronlike x rays from radiation pressure acceleration of a mass-limited foil target.

    Science.gov (United States)

    Yu, Tong-Pu; Pukhov, Alexander; Sheng, Zheng-Ming; Liu, Feng; Shvets, Gennady

    2013-01-25

    By using multidimensional particle-in-cell simulations, we study the electromagnetic emission from radiation pressure acceleration of ultrathin mass-limited foils. When a circularly polarized laser pulse irradiates the foil, the laser radiation pressure pushes the foil forward as a whole. The outer wings of the pulse continue to propagate and act as a natural undulator. Electrons move together with ions longitudinally but oscillate around the latter transversely, forming a self-organized helical electron bunch. When the electron oscillation frequency coincides with the laser frequency as witnessed by the electron, betatronlike resonance occurs. The emitted x rays by the resonant electrons have high brightness, short durations, and broad band ranges which may have diverse applications.

  9. Determination of neutron flux with an arbitrary energy distribution by measurement of irradiated foils activity

    International Nuclear Information System (INIS)

    Ljubenov, V.; Milosevic, M.

    2003-01-01

    A procedure for the neutron flux determination in a neutron field with an arbitrary energy spectrum, based on the using of standard methods for the measurement of irradiated foils activity and on the application of the SCALE-4.4a code system for averaged cross section calculation is described in this paper. Proposed procedure allows to include the energy spectrum of neutron flux reestablished in the location of irradiated foils and the resonance self-shielding effects in the foils also. Example application of this procedure is given for the neutron flux determination inside the neutron filter with boron placed in the centre of heavy water critical assembly RB at the Vinca Institute (author)

  10. Radon-thoron discrimination using a polythene foil: an application in uranium exploration

    International Nuclear Information System (INIS)

    Ramola, R.C.; Singh, M.; Sandhu, A.S.; Singh, S.; Virk, H.S.

    1989-01-01

    Integrated measurements of radon concentrations in subsurface soil are being used extensively for uranium exploration and earthquake prediction. For uranium exploration only the radon signals are needed; however, a part of the α-activity may derive from thoron. To exclude thoron, a polythene foil has been used as an anti-thoron membrane to delay the entry of thoron into the detector system so that only the longer lived isotope 222 Rn survives to be measured. A long term integrated measurement has been carried out using LR-115 and CR-39 plastic track detectors. The observed track density has been determined as a function of foil thickness. It is found that a polythene foil of appropriate thickness could be successfully employed for the separation of radon and thoron in soil. (author)

  11. Molecular beam epitaxy of single crystalline GaN nanowires on a flexible Ti foil

    Science.gov (United States)

    Calabrese, Gabriele; Corfdir, Pierre; Gao, Guanhui; Pfüller, Carsten; Trampert, Achim; Brandt, Oliver; Geelhaar, Lutz; Fernández-Garrido, Sergio

    2016-05-01

    We demonstrate the self-assembled growth of vertically aligned GaN nanowire ensembles on a flexible Ti foil by plasma-assisted molecular beam epitaxy. The analysis of single nanowires by transmission electron microscopy reveals that they are single crystalline. Low-temperature photoluminescence spectroscopy demonstrates that in comparison to standard GaN nanowires grown on Si, the nanowires prepared on the Ti foil exhibit an equivalent crystalline perfection, a higher density of basal-plane stacking faults, but a reduced density of inversion domain boundaries. The room-temperature photoluminescence spectrum of the nanowire ensemble is not influenced or degraded by the bending of the substrate. The present results pave the way for the fabrication of flexible optoelectronic devices based on GaN nanowires on metal foils.

  12. Molecular beam epitaxy of single crystalline GaN nanowires on a flexible Ti foil

    International Nuclear Information System (INIS)

    Calabrese, Gabriele; Corfdir, Pierre; Gao, Guanhui; Pfüller, Carsten; Trampert, Achim; Brandt, Oliver; Geelhaar, Lutz; Fernández-Garrido, Sergio

    2016-01-01

    We demonstrate the self-assembled growth of vertically aligned GaN nanowire ensembles on a flexible Ti foil by plasma-assisted molecular beam epitaxy. The analysis of single nanowires by transmission electron microscopy reveals that they are single crystalline. Low-temperature photoluminescence spectroscopy demonstrates that in comparison to standard GaN nanowires grown on Si, the nanowires prepared on the Ti foil exhibit an equivalent crystalline perfection, a higher density of basal-plane stacking faults, but a reduced density of inversion domain boundaries. The room-temperature photoluminescence spectrum of the nanowire ensemble is not influenced or degraded by the bending of the substrate. The present results pave the way for the fabrication of flexible optoelectronic devices based on GaN nanowires on metal foils.

  13. Slowing down of 100 keV antiprotons in Al foils

    Science.gov (United States)

    Nordlund, K.

    2018-03-01

    Using energy degrading foils to slow down antiprotons is of interest for producing antihydrogen atoms. I consider here the slowing down of 100 keV antiprotons, that will be produced in the ELENA storage ring under construction at CERN, to energies below 10 keV. At these low energies, they are suitable for efficient antihydrogen production. I simulate the antihydrogen motion and slowing down in Al foils using a recently developed molecular dynamics approach. The results show that the optimal Al foil thickness for slowing down the antiprotons to below 5 keV is 910 nm, and to below 10 keV is 840 nm. Also the lateral spreading of the transmitted antiprotons is reported and the uncertainties discussed.

  14. The Anomalous Currents In The Front Foils of the JET Lost Alpha Diagnostic KA-2

    Energy Technology Data Exchange (ETDEWEB)

    Cecil, F. E.; Kiptily, V.; Salmi, A.; Horton, A.; Fullard, K.; Murari, A.; Darrow, D.; Hill, K.

    2011-05-04

    We have examined the observed currents in the front foils of the JET Faraday cup lost alpha particle diagnostic KA-2. In particular, we have sought to understand the currents during Ohmic plasmas for which the ion flux at the detectors was initially assumed to be negligible. We have considered two sources of this current: plasma ions both deuterium and impurity in the vicinity of the detector including charge exchange neutrals and photoemission from scattered UV radiation. Based upon modeling and empirical observation, the latter source appears most likely and, moreover, seems to be applicable to the currents in the front foil during ELMy H-mode plasmas. A very thin gold or nickel foil attached to the present detector aperture is proposed as a solution to this problem, and realistic calculations of expected fluxes of lost energetic neutral beam ions during TF ripple experiments are presented as justification of this proposed solution.

  15. The development of uranium foil farication technology utilizing twin roll method for Mo-99 irradiation target

    CERN Document Server

    Kim, C K; Park, H D

    2002-01-01

    MDS Nordion in Canada, occupying about 75% of global supply of Mo-99 isotope, has provided the irradiation target of Mo-99 using the rod-type UAl sub x alloys with HEU(High Enrichment Uranium). ANL (Argonne National Laboratory) through co-operation with BATAN in Indonesia, leading RERTR (Reduced Enrichment for Research and Test Reactors) program substantially for nuclear non-proliferation, has designed and fabricated the annular cylinder of uranium targets, and successfully performed irradiation test, in order to develop the fabrication technology of fission Mo-99 using LEU(Low Enrichment Uranium). As the uranium foils could be fabricated in laboratory scale, not in commercialized scale by hot rolling method due to significant problems in foil quality, productivity and economic efficiency, attention has shifted to the development of new technology. Under these circumstances, the invention of uranium foil fabrication technology utilizing twin-roll casting method in KAERI is found to be able to fabricate LEU or...

  16. Identification of Impact Craters in Foils from the Stardust Interstellar Dust Collector

    Science.gov (United States)

    Stroud, R. M.; Allen, C.; Bajt, S.; Bechtel, H. A.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Burchell, M.; Burghammer, M.; hide

    2011-01-01

    The Stardust Interstellar Dust Collection tray provides the first opportunity for the direct laboratory-based measurement of contemporary interstellar dust. The total exposed surface of the tray was approximately 0.1 square meters, including 153 square centimeters of Al foil in addition to the silica aerogel tiles that are the primary collection medium. Preliminary examination of aerogel tiles has already revealed 16 tracks from particle impacts with an orientation consistent with an interstellar origin, and to date four of the particles associated with these tracks have a composition consistent with an extraterrestrial origin. Tentative identification of impact craters on three foil samples was also reported previously. Here we present the definitive identification of 20 impact craters on five foils.

  17. Modelling the deformation of nickel foil during manufacturing of nanostructures on injection moulding tool inserts

    DEFF Research Database (Denmark)

    Sonne, Mads Rostgaard; Cech, Jiri; Pranov, H.

    2016-01-01

    In the present work, a manufacturing process for transferring nanostructures from a glass wafer, to a double-curvedinsert for injection moulding is demonstrated. A nanostructure consisting of sinusoidal cross-gratings with a period of 426 nm issuccessfully transferred to hemispheres on an aluminium...... substrate with three different radii; 500 μm, 1000 μm and 2000 μm,respectively. The nanoimprint is performed using a 50 μm thick nickel foil, manufactured using electroforming. During theimprinting process, the nickel foil is stretched due to the curved surface of the aluminium substrate. Experimentally......, it is possibleto address this stretch by counting the periods of the cross-gratings via SEM characterization. A model for the deformation of thenickel foil during nanoimprint is developed, utilizing non-linear material and geometrical behaviour. Good agreement betweenmeasured and numerically calculated stretch...

  18. 2-D numerical study of the hydrodynamics of laser accelerated foils

    International Nuclear Information System (INIS)

    Atzeni, S.

    1989-01-01

    The large scale hydrodynamics of laser accelerated thin disks (foils) are studied numerically using a 2-D, evolutionary Lagrangian fluid code. The laser and target parameters considered are relevant to direct drive laser fusion, in the classical interaction regime. Peculiar 2-D features observed in the experiments are recovered in the simulations; agreement with experimental data is found for a series of experiments concerning foils of different thickness. Scaling laws for the design of hydrodynamically equivalent experiments are tested, with the effects of non-scaled processes turning out to be fairly small, although observable, and qualitatively in agreement with the relevant theory. Simulations also indicate the adequacy of foil acceleration experiments driven by non-uniform (but controlled) beams to the quantitative study of the smoothing of the irradiation non-uniformities. (author)

  19. Determination of low-energy ion-induced electron yields from thin carbon foils

    International Nuclear Information System (INIS)

    Allegrini, Frederic; Wimmer-Schweingruber, Robert F.; Wurz, Peter; Bochsler, Peter

    2003-01-01

    Ion beams crossing thin carbon foils can cause electron emission from the entrance and exit surface. Thin carbon foils are used in various types of time-of-flight (TOF) mass spectrometers to produce start pulses for TOF measurements. The yield of emitted electrons depends, among other parameters, on the energy of the incoming ion and its mass, and it has been experimentally determined for a few projectile elements. The electron emission yield is of great importance for deriving abundance ratios of elements and isotopes in space plasmas using TOF mass spectrometers. We have developed a detector for measuring ion-induced electron yields, and we have extended the electron yield measurements for oxygen to energies relevant for solar wind research. We also present first measurements of the carbon foil electron emission yield for argon and iron in the solar wind energy range

  20. Aluminum nanostructures for ultraviolet plasmonics

    Science.gov (United States)

    Martin, Jérôme; Khlopin, Dmitry; Zhang, Feifei; Schuermans, Silvère; Proust, Julien; Maurer, Thomas; Gérard, Davy; Plain, Jérôme

    2017-08-01

    An electromagnetic field is able to produce a collective oscillation of free electrons at a metal surface. This allows light to be concentrated in volumes smaller than its wavelength. The resulting waves, called surface plasmons can be applied in various technological applications such as ultra-sensitive sensing, Surface Enhanced Raman Spectroscopy, or metal-enhanced fluorescence, to name a few. For several decades plasmonics has been almost exclusively studied in the visible region by using nanoparticles made of gold or silver as these noble metals support plasmonic resonances in the visible and near-infrared range. Nevertheless, emerging applications will require the extension of nano-plasmonics toward higher energies, in the ultraviolet range. Aluminum is one of the most appealing metal for pushing plasmonics up to ultraviolet energies. The subsequent applications in the field of nano-optics are various. This metal is therefore a highly promising material for commercial applications in the field of ultraviolet nano-optics. As a consequence, aluminum (or ultraviolet, UV) plasmonics has emerged quite recently. Aluminium plasmonics has been demonstrated efficient for numerous potential applications including non-linear optics, enhanced fluorescence, UV-Surface Enhanced Raman Spectroscopy, optoelectronics, plasmonic assisted solid-state lasing, photocatalysis, structural colors and data storage. In this article, different preparation methods developed in the laboratory to obtain aluminum nanostructures with different geometries are presented. Their optical and morphological characterizations of the nanostructures are given and some proof of principle applications such as fluorescence enhancement are discussed.

  1. Measurements of activation products associated with Havar foils from a GE PETtrace medical cyclotron using high resolution gamma spectroscopy.

    Science.gov (United States)

    Manickam, Vivek; Brey, Richard R; Jenkins, Peter A; Christian, Paul E

    2009-02-01

    Havar foils are specially engineered for beam-line windows used in the General Electric (GE) PETtrace medical cyclotron that can withstand the high pressure differentials and also temperatures developed near the target with proton bombardment. These foils effectively separate components along the beam line of the cyclotron. Various activation products are produced in the foils from the primary proton beam and other secondary radiations. An accurate estimate of the activation products is necessary for the disposal of these foils. The foils were assayed using two High Purity Germanium (HPGe) detectors calibrated over a wide energy range. These were positioned at different distances (0.10 m, 0.24 m, and 1.74 m) away from the detector faces to accommodate their high activities. A summary of the anticipated relative abundance of each activation product and a scatter plot of the average exposure rate per unit charge incident on the foil vs. time post-activation are provided. A detailed spectral analysis of the foils in the energy ranges between 12 keV to 300 keV and 12 keV through 2,500 keV revealed the residual activation products 56Co, 57Co, 58Co, 54Mn, and 183Re at 264 d post-irradiation. Spectral examinations of the different foils removed between 2003 and 2005 show the same activation products regardless of the irradiation time or foil position in the target assembly. The information presented in this paper can be used along with the integrated charge incident on the foils in estimating the activity of Havar foils for the purpose of disposal.

  2. Undulatory locomotion of flexible foils as biomimetic models for understanding fish propulsion.

    Science.gov (United States)

    Shelton, Ryan M; Thornycroft, Patrick J M; Lauder, George V

    2014-06-15

    An undulatory pattern of body bending in which waves pass along the body from head to tail is a major mechanism of creating thrust in many fish species during steady locomotion. Analyses of live fish swimming have provided the foundation of our current understanding of undulatory locomotion, but our inability to experimentally manipulate key variables such as body length, flexural stiffness and tailbeat frequency in freely swimming fish has limited our ability to investigate a number of important features of undulatory propulsion. In this paper we use a mechanical flapping apparatus to create an undulatory wave in swimming flexible foils driven with a heave motion at their leading edge, and compare this motion with body bending patterns of bluegill sunfish (Lepomis macrochirus) and clown knifefish (Notopterus chitala). We found similar swimming speeds, Reynolds and Strouhal numbers, and patterns of curvature and shape between these fish and foils, suggesting that flexible foils provide a useful model for understanding fish undulatory locomotion. We swam foils with different lengths, stiffnesses and heave frequencies while measuring forces, torques and hydrodynamics. From measured forces and torques we calculated thrust and power coefficients, work and cost of transport for each foil. We found that increasing frequency and stiffness produced faster swimming speeds and more thrust. Increasing length had minimal impact on swimming speed, but had a large impact on Strouhal number, thrust coefficient and cost of transport. Foils that were both stiff and long had the lowest cost of transport (in mJ m(-1) g(-1)) at low cycle frequencies, and the ability to reach the highest speed at high cycle frequencies. © 2014. Published by The Company of Biologists Ltd.

  3. Flapping foil power generator performance enhanced with a spring-connected tail

    Science.gov (United States)

    Liu, Zhengliang; Tian, Fang-Bao; Young, John; Lai, Joseph C. S.

    2017-12-01

    The flexibility effects on the performance of a flapping foil power generator are numerically studied by using the immersed boundary-lattice Boltzmann method at a Reynolds number of 1100. The flapping foil system consists of a rigid NACA0015 foil undergoing harmonic pitch and plunge motions and a passively actuated flat plate pinned to the trailing edge of the rigid foil. The flexibility is modeled by a torsional spring model at the conjuncture of the rigid foil and the tail. Here, a parametric study on mass density and natural frequency is conducted under the optimum kinematic condition of the rigid system identified from the literature and numerical simulations made for reduced frequency f* = 0.04-0.24 and pitch amplitude θ0 = 40°-90°. Four typical cases are discussed in detail by considering time histories of hydrodynamic loads and tail deformations under the optimal and non-optimal kinematic conditions. Results show that under the rigid-system optimal kinematic condition, a tail with appropriate mass density (μ = 0.60) and resonant frequency ( fr*=1.18 ) can improve the maximum efficiency by 7.24% accompanied by an increase of 6.63% in power compared to those of a rigid foil with a rigid tail. This is because the deflection of the tail reduces the low pressure region on the pressure surface (i.e., the lower surface during the upstroke or the upper surface during the downstroke) caused by the leading edge vortex after the stroke reversal, resulting in a higher efficiency. At high flapping frequencies, a spring-connected tail ( fr*=0.13 ) eliminates the large spike in the moment observed in high stiffness cases, reducing the power required for the pitch motion, resulting in 117% improvement in efficiency over that with a rigid tail at a reduced frequency of 0.24.

  4. Extraction of Solar Wind Nitrogen and Noble Gases From the Genesis Gold Foil Collector

    Science.gov (United States)

    Schlutter, D. J.; Pepin, R. O.

    2005-12-01

    The Genesis gold foil is a bulk solar wind collector, integrating fluences from all three of the wind regimes. Pyrolytic extraction of small foil samples at Minnesota yielded He fluences, corrected for backscatter, in good agreement with measurements by on-board spacecraft instruments, and He/Ne elemental ratios close to those implanted in collector foils deployed on the lunar surface during the Apollo missions. Isotopic distributions of He, Ne and Ar are under study. Pyrolysis to temperatures above the gold melting point generates nitrogen blanks large enough to obscure the solar-wind nitrogen component. An alternative technique for nitrogen and noble gas extraction, by room-temperature amalgamation of the gold foil surface, will be discussed. Ne and Ar releases in preliminary tests of this technique on small foil samples were close to 100% of the amounts expected from the high-temperature pyrolysis yields, indicating that amalgamation quantitatively liberates gases from several hundred angstroms deep in the gold, beyond the implantation depth of most of the solar wind. Present work is focused on two problems currently interfering with accurate nitrogen measurements at the required picogram to sub-picogram levels: a higher than expected blank likely due to tiny air bubbles rolled into the gold sheet during fabrication, and the presence of a refractory hydrocarbon film on Genesis collector surfaces (the "brown stain") that, if left in place on the foil, shields the underlying gold from mercury attack. We have found, however, that the film is efficiently removed within tens of seconds by oxygen plasma ashing. Potential nitrogen contaminants introduced during the crash of the sample return canister are inert in amalgamation, and so are not hazards to the measurements.

  5. Deformation of a Beryllium-Aluminum Composite

    Energy Technology Data Exchange (ETDEWEB)

    Carter, David H. [Univ. of California, Santa Barbara, CA (United States)

    2000-03-01

    The physical and mechanical properties of beryllium, especially the combina- tion of low density and high elastic modulus, make it an attractive candidate for a structural material. Intrinsic problems exist with Be as a monolithic material, as its structural behavior is complex due to its hexagonal close-packed crystal structure. Therefore, great value may be found in investigating composites of Be, such as beryllium-aluminum. However, one needs to understand the behavior of the individual phases in a Be composite and their interaction during the sequence of elasticity, plasticity, and fracture. The approach taken in this dissertation was to use neutron di raction to monitor the elastic loading of each phase, in combi- nation with detailed studies of the composite's mechanical behavior for strains up to 5%. In addition, the experiments were performed on a unique type of compos- ite microstructure. This consisted of interpenetrating phases formed from liquid immiscibility, rather than conventional powder processing, which is limited by reactions at interfaces. The results were interpreted in terms of plasticity models and nite element calculations that describe the interaction between the phases and the local stress states established by compatibility requirements between the phases.

  6. Observation of Rayleigh-Taylor-like structures in a laser-accelerated foil

    International Nuclear Information System (INIS)

    Whitlock, R.R.; Emery, M.H.; Stamper, J.A.; McLean, E.A.; Obenschain, S.P.; Peckerar, M.C.

    1984-01-01

    Laser-accelerated targets have been predicted to be subject to the Rayleigh-Taylor hydrodynamic instability. The development of the instability was studied by introducing mass thickness variations in foil targets and observing the development of the target nonuniformities by side-on flash x radiography. Observations were made of target structures and mass redistribution effects which resemble Rayleigh-Taylor bubbles and spikes, including not only advanced broadening of the spike tips on the laser-irradiated side of the foil but also projections of mass on the unirradiated side. The observations compare well with numerical simulations

  7. Doping of polycrystalline CdTe for high-efficiency solar cells on flexible metal foil

    OpenAIRE

    Kranz Lukas; Gretener Christina; Perrenoud Julian; Schmitt Rafael; Pianezzi Fabian; La Mattina Fabio; Blösch Patrick; Cheah Erik; Chirila Adrian; Fella Carolin M.; Hagendorfer Harald; Jäger Timo; Nishiwaki Shiro; Uhl Alexander R.; Buecheler S.

    2013-01-01

    Roll to roll manufacturing of CdTe solar cells on flexible metal foil substrates is one of the most attractive options for low cost photovoltaic module production. However various efforts to grow CdTe solar cells on metal foil have resulted in low efficiencies. This is caused by the fact that the conventional device structure must be inverted which imposes severe restrictions on device processing and consequently limits the electronic quality of the CdTe layer. Here we introduce an innovative...

  8. Stopping power and scattering angle calculations of charged particle beams through thin foils

    International Nuclear Information System (INIS)

    Nassiri, A.

    1991-03-01

    It is important to understand the effects of introducing foils into the path of charged particle beams. In the APS linac system, the intention is to insert thin foils before and after the positron generating target to protect the accelerating structures immediately before and after the target. Electron beams that pass through a dense material lose energy in collisions with the atomic electrons. The scattering path of electrons is much less straight than that of heavier particles (mu, pi meson, K meson, proton, etc.). After a short distance electrons tend to diffuse into the material, rather than proceeding in a rectilinear path

  9. A finite element framework for distortion gradient plasticity with applications to bending of thin foils

    DEFF Research Database (Denmark)

    Martínez Pañeda, Emilio; Niordson, Christian Frithiof; Bardella, Lorenzo

    2016-01-01

    by Gurtin (2004) through the prescription of a free energy dependent on Nye’s dislocation density tensor. The proposed numerical scheme is developed by following and extending the mathematical principles established by Fleck and Willis (2009). The modeling of thin metallic foils under bending reveals...... a significant influence of the plastic shear strain and spin due to a mechanism associated with the higher-order boundary conditions allowing dislocations to exit the body. This mechanism leads to an unexpected mechanical response in terms of bending moment versus curvature, dependent on the foil length...

  10. Visualization and Measurement of the Deflagration of Metal-Foil Bounded JA2

    Science.gov (United States)

    2015-06-01

    ARL‐TR‐7322 ● JUNE 2015          US Army Research Laboratory      Visualization and Measurement of the  Deflagration of Metal‐ Foil  Bounded...Visualization and Measurement of the  Deflagration of Metal‐ Foil  Bounded JA2    John J Ritter and Anthony Canami  Weapons and Materials Research...

  11. Simulations of micro-bending of thin foils using a scale dependent crystal plasticity model

    DEFF Research Database (Denmark)

    Kuroda, Mitsutoshi; Tvergaard, Viggo; Ohashi, T.

    2007-01-01

    In this paper, we perform crystal plasticity analyses of micro-bending of thin f.c.c. metal foils having thicknesses ranging from 10 to 50 mu m. The scale dependent crystal plasticity model used here is a viscoplastic finite strain version of the model proposed by Ohashi (2005 Int. J. Plast. 21...... a Bailey-Hirsch type relation. The computational results are compared with the experimental results for Ni foils, reported in Stolken and Evans (1998 Acta Mater. 46 5109-15). The validity of the current model and the direction of future development of the 'physically-based' scale dependent crystal...

  12. Femtosecond laser ablation of silver foil with single and double pulses

    CSIR Research Space (South Africa)

    Roberts, DE

    2009-01-01

    Full Text Available /apsusc r ablation of silver foil with single and double pulses, Appl. Surf. D.E. Roberts et al. / Applied Surface Science xxx (2009) xxx–xxx2 G Model APSUSC-19322; No of Pages 9 pulses used for ablation. While there has been much overlap in the aims... value r ablation of silver foil with single and double pulses, Appl. Surf. ; lon D.E. Roberts et al. / Applied Surface Science xxx (2009) xxx–xxx 3 G Model APSUSC-19322; No of Pages 9 Fig. 1. Surface temperature versus time calculated for double...

  13. Chemical etching of copper foils for single-layer graphene growth by chemical vapor deposition

    Science.gov (United States)

    Yoshihara, Naoki; Noda, Masaru

    2017-10-01

    Chemical etching on copper surface is essential as a pre-treatment for single-layer graphene growth by chemical vapor deposition (CVD). Here, we investigated the effect of chemical etching treatment on copper foils for single-layer graphene CVD growth. The chemical etching conditions, such as the type of chemical etchants and the treatment time, were found to strongly influence the graphene domain size. Moreover, a drastic change in the layer structure of graphene sheets, which was attributed to the surface morphology of the etched copper foil, was confirmed by graphene transmittance and Raman mapping measurements.

  14. Potentiality of the composite fulleren based carbon films as the stripper foils for tandem accelerators

    CERN Document Server

    Vasin, A V; Rusavsky, A V; Totsky, Y I; Vishnevski, I N

    2001-01-01

    The problem of the radiation resistance of the carbon stripper foils is considered. The short review of the experimental data available in literature and original experimental results of the are presented. In the paper discussed is the possibility of composite fulleren based carbon films to be used for preparation of the stripper foils. Some technological methods for preparation of composite fulleren based carbon films are proposed. Raman scattering and atom force microscopy were used for investigation of the fulleren and composite films deposited by evaporation of the C sub 6 sub 0 fulleren powder.

  15. Quality assurance of GEM foils in the framework of the TPC upgrade in the ALICE experiment

    CERN Document Server

    Ozcelik, Melih Arslan

    2016-01-01

    In the framework of the TPC upgrade of the ALICE Experiment, new readout chambers will be installed during the LHC long shutdown 2, which is scheduled to start in July 2018. The current MWPCs (Multi Wire Proportional Chambers) will be replaced by readout chambers consisting of GEM (Gas Electron Multipliers) foils in order to meet the increasing readout rate requirements. QA (Quality Assurance) tests on the GEMs are performed to classify the foils. In this report we present the work done during the CERN Summer Student Programme 2016.

  16. Wake structure and thrust generation of a flapping foil in two-dimensional flow

    DEFF Research Database (Denmark)

    Andersen, Anders Peter; Bohr, Tomas; Schnipper, Teis

    2017-01-01

    We present a combined numerical (particle vortex method) and experimental (soap film tunnel) study of a symmetric foil undergoing prescribed oscillations in a two-dimensional free stream. We explore pure pitching and pure heaving, and contrast these two generic types of kinematics. We compare...... measurements and simulations when the foil is forced with pitching oscillations, and we find a close correspondence between flow visualisations using thickness variations in the soap film and the numerically determined vortex structures. Numerically, we determine wake maps spanned by oscillation frequency...

  17. Hydrodynamic simulations of light ion beam-matter interactions: ablative acceleration of thin foils

    International Nuclear Information System (INIS)

    Devore, C.R.; Gardner, J.H.; Boris, J.P.; Mosher, D.

    1984-01-01

    A one-dimensional model is used to study the hydrodynamic response of thin foils to bombardment by an intense proton beam. The beam targets are single- and multilayer planar foils of gold and polystyrene. The main conclusion is that the efficiency of conversion of incident beam energy to directed kinetic energy of the target is maximized by using a multilayer design. For beam parameters associated with the Gamble II device at the Naval Research Laboratory, the simulations yield payload velocities of over 5 cm/μs and energy conversion efficiencies of over 30%. The implications of these results for inertial confinement fusion research are discussed. (author)

  18. First storage of ultracold neutrons using foils coated with diamond-like carbon

    International Nuclear Information System (INIS)

    Atchison, F.; Brys, T.; Daum, M.; Fierlinger, P.; Geltenbort, P.; Henneck, R.; Heule, S.; Kasprzak, M.; Kirch, K.; Pichlmaier, A.; Plonka, C.; Straumann, U.; Wermelinger, C.

    2005-01-01

    For the first time, ultracold neutrons have been stored in a volume formed of foils coated with diamond-like carbon. The coefficients for loss, η, and depolarization, β, per wall collision were determined simultaneously. The results for different samples, η∼10 -4 and β∼10 -5 -10 -6 , are among the best values measured for high Fermi potential materials without elaborate surface pre-treatment. Thin foil storage material will be widely applicable, e.g., in neutron β-decay studies

  19. First storage of ultracold neutrons using foils coated with diamond-like carbon

    Energy Technology Data Exchange (ETDEWEB)

    Atchison, F. [PSI, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Brys, T. [PSI, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Daum, M. [PSI, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Fierlinger, P. [PSI, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Physik-Institut, Universitaet Zuerich (Switzerland); Geltenbort, P. [ILL, Institut Laue-Langevin, Grenoble (France); Henneck, R. [PSI, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Heule, S. [PSI, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Physik-Institut, Universitaet Zuerich (Switzerland); Kasprzak, M. [PSI, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); SMI, Stefan-Meyer-Institut, Vienna (Austria); Kirch, K. [PSI, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Pichlmaier, A. [PSI, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)]. E-mail: axel.pichlmaier@psi.ch; Plonka, C. [ILL, Institut Laue-Langevin, Grenoble (France); Straumann, U. [Physik-Institut, Universitaet Zuerich (Switzerland); Wermelinger, C. [PSI, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); ETHZ, Eidgenoessische Technische Hochschule Zuerich (Switzerland)

    2005-10-06

    For the first time, ultracold neutrons have been stored in a volume formed of foils coated with diamond-like carbon. The coefficients for loss, {eta}, and depolarization, {beta}, per wall collision were determined simultaneously. The results for different samples, {eta}{approx}10{sup -4} and {beta}{approx}10{sup -5}-10{sup -6}, are among the best values measured for high Fermi potential materials without elaborate surface pre-treatment. Thin foil storage material will be widely applicable, e.g., in neutron {beta}-decay studies.

  20. Large-area thin self-supporting carbon foils with MgO coatings

    CERN Document Server

    Stolarz, A

    2002-01-01

    Large area self-supporting carbon foils in the thickness of range of 8-22 mu g/cm sup 2 , coated with approximately 4 mu g/cm sup 2 MgO have been prepared by e-gun evaporation. They were mounted on frames with apertures of 130 cm sup 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.