Science.gov

Sample records for non-evaporable getter films

  1. Deposition of non evaporable getter films and their vacuum performance

    NASA Astrophysics Data System (ADS)

    Bansod, Tripti; Sindal, B. K.; Kumar, Kvanps; Shukla, S. K.

    2012-06-01

    Use of NEG coating as an integrated pump in accelerators is state of art technique to pump them in UHV range. At UHVTD, RRCAT development of these coatings has also been started. A UHV compatible cylindrical DC magnetron sputtering system was developed for this purpose and evolution of optimized NEG coating parameters is under investigation. Ti-Zr-V NEG films were coated on 400mm and 925mm long chamber with 100mm diameter. Preliminary vacuum performances like ultimate vacuum testing and activation studies with CO pumping for a NEG chamber were studied, which clearly demonstrates large pumping speed for CO.

  2. Preparation and Characterization of Ti-Zr-V Non-Evaporable Getter Films to Be Used in Ultra-High Vacuum

    SciTech Connect

    Ferreira, Marcelo J.; Tallarico, Denise A.; Nascente, Pedro A. P.

    2009-01-29

    An appealing procedure to obtain operating pressures in the 10{sup -8} Pa range, which is necessary for the insertion devices elements of synchrotron sources, is to coat the inner ultra-high vacuum chamber walls with a thin film of non-evaporable getter (NEG) metals. Titanium, zirconium, vanadium, and their alloys are used as NEG materials due to their low activation temperature, high chemical activity, large solubility, and high diffusivity for gases. In this work, magnetron sputtering was employed to deposit thin films of Ti-Zr-V on a Si(111) substrate. The morphological, structural, and chemical analyses were carried out by atomic force microscopy (AFM), scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS)

  3. Use of non evaporable getter pumps to ensure long term performances of high quantum efficiency photocathodes

    SciTech Connect

    Sertore, Daniele Michelato, Paolo; Monaco, Laura; Manini, Paolo; Siviero, Fabrizio

    2014-05-15

    High quantum efficiency photocathodes are routinely used as laser triggered emitters in the advanced high brightness electron sources based on radio frequency guns. The sensitivity of “semiconductor” type photocathodes to vacuum levels and gas composition requires special care during preparation and handling. This paper will discuss the results obtained using a novel pumping approach based on coupling a 20 l s{sup −1} sputter ion getter pump with a CapaciTorr® D100 non evaporable getter (NEG) pump. A pressure of 8⋅10{sup −8} Pa was achieved using only a sputter ion pump after a 6 day bake-out. With the addition of a NEG pump, a pressure of 2⋅10{sup −9} Pa was achieved after a 2 day bake-out. These pressure values were maintained without power due to the ability of the NEG to pump gases by chemical reaction. Long term monitoring of cathodes quantum efficiencies was also carried out at different photon wavelengths for more than two years, showing no degradation of the photoemissive film properties.

  4. RF surface resistance study of non-evaporable getter coatings

    NASA Astrophysics Data System (ADS)

    Malyshev, Oleg B.; Gurran, Lewis; Goudket, Philippe; Marinov, Kiril; Wilde, Stuart; Valizadeh, Reza; Burt, Graeme

    2017-02-01

    In many particle accelerators the beam parameters could be affected by the beam pipe wakefield impedance. It is vital to understand how the wakefield impedance might vary due to various coatings on the surface of the vacuum chamber, and this can be derived from surface resistance measurements. The bulk conductivity of two types of NEG films (dense and columnar) is determined. This is achieved by measuring the surface resistance of NEG-coated samples using an RF test cavity and fitting the experimental data to a standard theoretical model. The conductivity values obtained are then used to compare resistive wall wakefield effects in beam pipes coated with either of the two types of film.

  5. Non evaporable getter (NEG) technology: A powerful tool for UHV-XHV systems

    NASA Astrophysics Data System (ADS)

    Maccallini, Enrico; Siviero, Fabrizio; Bonucci, Antonio; Conte, Andrea; Srivastava, Peeyush; Paolo, Manini

    2012-06-01

    Ultra and Extreme High Vacuum (UHV and XHV respectively) levels are needed in several vacuum-related applications for wide pressure and time range. The Non Evaporable Getter (NEG) technology is one of the most important examples to get XHV/UHV condition in the vacuum systems. In fact the high reactivity of the getter materials towards active gases in a wide temperature range (from room temperature to several hundreds of °C) allows removing very efficiently active gases such as H2, H2O, CO2, CO, N2, and so on. When declining, the pumping speed of NEG can be easily restored, by reactivating the getter material with a thermal process ("reactivation"). In this framework, SAES Getters S.p.A. has a long expertise in producing NEG pumps (and more in general NEG technology) which can provide vacuum conditions from the low to the ultra high level. An overall overview of NEG pump technology will be given in this paper considering 1) the involved mechanisms for gas adsorption into the NEG material, 2) operational conditions of NEG pumps and 3) example of applications which demonstrate the benefits of NEG pumps use in XHV/UHV systems. Future perspectives for NEG pumps in UHV/XHV applications will be also given.

  6. Hydrogen capacity and absorption rate of the SAES St707 non-evaporable getter at various temperatures.

    SciTech Connect

    Hsu, Irving; Mills, Bernice E.

    2010-08-01

    A prototype of a tritium thermoelectric generator (TTG) is currently being developed at Sandia. In the TTG, a vacuum jacket reduces the amount of heat lost from the high temperature source via convection. However, outgassing presents challenges to maintaining a vacuum for many years. Getters are chemically active substances that scavenge residual gases in a vacuum system. In order to maintain the vacuum jacket at approximately 1.0 x 10{sup -4} torr for decades, nonevaporable getters that can operate from -55 C to 60 C are going to be used. This paper focuses on the hydrogen capacity and absorption rate of the St707{trademark} non-evaporable getter by SAES. Using a getter testing manifold, we have carried out experiments to test these characteristics of the getter over the temperature range of -77 C to 60 C. The results from this study can be used to size the getter appropriately.

  7. Distributed Non-evaporable Getter pumps for the storage ring of the APS

    SciTech Connect

    Dortwegt, R.; Benaroya, R.

    1993-07-01

    A pair of distributed Non-evaporable Getter (NeG) strip assemblies is installed in each of 236 aluminum vacuum chambers of the 1104-m storage ring of the Advanced Photon Source. Distributed pumping is provided to remove most of the gas resulting from photon-stimulated desorption occurring along the outer walls of the chambers. This is an efficient way of pumping because conductance is limited along the beam axis. The St-707 NeG strips are conditioned at 450{degree}C for 45 min. with 42 A. Base pressures obtained are also as low as 4 {times} 10{sup 11} Torr. The NeG strip assemblies are supported by a series of electrically isolated, 125-mm-long, interlocking stainless steel carriers. These unique interlocking carrier elements provide flexibility along the vacuum chamber curvature (r=38.96 m) and permit removal and installation of assemblies with as little as 150 mm external clearance between adjacent chambers.

  8. Operation of a high-gradient superconducting radio-frequency cavity with a non-evaporable getter pump

    SciTech Connect

    Ciovati, G.; Geng, R.; Lushtak, Y.; Manini, P.; Maccallini, E.; Stutzman, M.

    2016-10-28

    The use of non-evaporable getter (NEG) pumps in particle accelerators has increased significantly over the past few years because of their large pumping speed, particularly for hydrogen, compared to the size of the pump. A concern about using such pumps in superconducting radio-frequency (SRF) accelerators is the possibility of shedding particulates which could then migrate into the SRF cavities and produce field emission, therefore degrading the cavity performance. One option to mitigate such issue is to use sintered getter materials which intrinsically offer superior mechanical and particle retention properties. In this article we present the results from cryogenic RF tests of a high-gradient SRF cavity after being evacuated several times with an NEG pump equipped with sintered getter disks and placed in close proximity to the cavity. Here, the results showed that the cavity performance was not affected by the pump up to the quench gradient of 34 MV/m. As a result of this study, two such NEG pumps have been installed next to a cryomodule in the CEBAF accelerator to maintain ultra-high vacuum in the SRF cryomodule and two adjacent warm girder sections.

  9. Operation of a high-gradient superconducting radio-frequency cavity with a non-evaporable getter pump

    DOE PAGES

    Ciovati, G.; Geng, R.; Lushtak, Y.; ...

    2016-10-28

    The use of non-evaporable getter (NEG) pumps in particle accelerators has increased significantly over the past few years because of their large pumping speed, particularly for hydrogen, compared to the size of the pump. A concern about using such pumps in superconducting radio-frequency (SRF) accelerators is the possibility of shedding particulates which could then migrate into the SRF cavities and produce field emission, therefore degrading the cavity performance. One option to mitigate such issue is to use sintered getter materials which intrinsically offer superior mechanical and particle retention properties. In this article we present the results from cryogenic RF testsmore » of a high-gradient SRF cavity after being evacuated several times with an NEG pump equipped with sintered getter disks and placed in close proximity to the cavity. Here, the results showed that the cavity performance was not affected by the pump up to the quench gradient of 34 MV/m. As a result of this study, two such NEG pumps have been installed next to a cryomodule in the CEBAF accelerator to maintain ultra-high vacuum in the SRF cryomodule and two adjacent warm girder sections.« less

  10. Low temperature activation of Au/Ti getter film for application to wafer-level vacuum packaging

    NASA Astrophysics Data System (ADS)

    Wu, Ming; Moulin, Johan; Lani, Sébastien; Hallais, Géraldine; Renard, Charles; Bosseboeuf, Alain

    2015-03-01

    Non-evaporable getter (NEG) thin films based on alloys of transition metals have been studied by various authors for vacuum control in wafer-level packages of micro electro mechanical systems (MEMS). These materials have typically a relatively high activation temperature (300-450 °C) which is incompatible with some temperature sensitive MEMS devices. In this work we investigate the potential of Au/Ti system with a thin or ultrathin non oxidizable Au layer as a low activation temperature getter material. In this bilayer system, gettering activation is produced by thermal outdiffusion of titanium atoms through the gold film. The outdiffusion kinetics of titanium was modelled and characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Rutherford backscattering spectrometry (RBS) at various temperatures. Results confirm that Au/Ti bilayer is a promising getter material for wafer-level packaging with an activation temperature below 300 °C for 1 h annealing time.

  11. ZrCoCe Getter Films for MEMS Vacuum Packaging

    NASA Astrophysics Data System (ADS)

    Xu, Yaohua; Cui, Jiandong; Cui, Hang; Zhou, Hao; Yang, Zhimin; Du, Jun

    2016-01-01

    In order to specifically support the technology trend of increased miniaturization of micro electro mechanical systems (MEMS) devices, highly porous ZrCoCe non-evaporable getter (NEG) film has been produced by direct current magnetron sputtering from a preformed ZrCoCe alloy target. Scanning electron microscopy and x-ray diffraction analysis indicated that the ZrCoCe film is constructed with porous columnar crystals, which are further built up with assembled ZrCoCe amorphous or nanocrystalline grains with an average grain size of 5 nm. Gas sorption investigation shows that this film can be activated at a low temperature of 300°C for 30 min and has excellent stable sorption characteristics. Sorption properties can be further improved with elevating activation temperatures due to nanocrystals growing and amorphous regions crystallizing. The capability of ZrCoCe films to withstand wafer physical or chemical cleaning processes is investigated, indicating their compatibility with MEMS vacuum packaging and the appropriate way to store them.

  12. Evolution of gettering technologies for vacuum tubes to getters for MEMS

    NASA Astrophysics Data System (ADS)

    Amiotti, M.

    2008-05-01

    Getter materials are technically proven and industrially accepted practical ways to maintain vacuum inside hermetically sealed tubes or devices to assure high reliability and long lifetime of the operating devices. The most industrially proven vacuum tube is the cathode rays tubes (CRTs), where large surfaces are available for the deposition of an evaporated barium film by a radio frequency inductive heating of a stainless steel container filled with a BaAl4 powder mixed to Ni powder. The evolution of the CRTs manufacturing technologies required also new types of barium getters able to withstand some thermal process in air without any deterioration of the evaporation characteristics. In other vacuum tubes such as traveling waves tubes, the space available for the evaporation of a barium film and the sorption capacity required to assure the vacuum for the lifetime of the devices did not allow the use of the barium film, prompting the development of sintered non evaporable getter pills that can be activated during the manufacturing process or by flowing current through an embedded resistance. The same sintered non evaporable getter pills could find usage also in evacuated parts to thermally isolate the infrared sensors for different final applications. In high energy physics particle accelerators, the getter technology moved from localized vacuum getter pumps or getter strips to a getter coating over the surface of vacuum chambers in order to guarantee a more uniform pumping speed. With the advent of solid state electronics, new challenges faced the getter technology to assure long life to vacuum or inert gas filled hermetical packages containing microelectronic devices, especially in the telecommunication and military applications. A well known problem of GaAs devices with Pd or Pt metalization is the H2 poisoning of the metal gate: to prevent this degradation a two layer getter film has been develop to absorb a large quantity of H2 per unit of getter surface. The

  13. Phosphorous and aluminum gettering in Silicon-Film{trademark} Product II material

    SciTech Connect

    Cotter, J.E.; Barnett, A.M.; Hall, R.B.

    1995-08-01

    Gettering processes are being developed for the Silicon-Film{trademark} Product II solar cell structure. These processes have been developed specifically for films of silicon grown on dissimilar substrates with barrier layers. Gettering with both phosphorous- and aluminum-based processing sequences has resulted in enhancement of minority carrier diffusion length. Long diffusion lengths have allowed the characterization of light trapping in thin films of silicon grown on barrier-coated substrates.

  14. Gettering of interstitial iron in silicon by plasma-enhanced chemical vapour deposited silicon nitride films

    NASA Astrophysics Data System (ADS)

    Liu, A. Y.; Sun, C.; Markevich, V. P.; Peaker, A. R.; Murphy, J. D.; Macdonald, D.

    2016-11-01

    It is known that the interstitial iron concentration in silicon is reduced after annealing silicon wafers coated with plasma-enhanced chemical vapour deposited (PECVD) silicon nitride films. The underlying mechanism for the significant iron reduction has remained unclear and is investigated in this work. Secondary ion mass spectrometry (SIMS) depth profiling of iron is performed on annealed iron-contaminated single-crystalline silicon wafers passivated with PECVD silicon nitride films. SIMS measurements reveal a high concentration of iron uniformly distributed in the annealed silicon nitride films. This accumulation of iron in the silicon nitride film matches the interstitial iron loss in the silicon bulk. This finding conclusively shows that the interstitial iron is gettered by the silicon nitride films during annealing over a wide temperature range from 250 °C to 900 °C, via a segregation gettering effect. Further experimental evidence is presented to support this finding. Deep-level transient spectroscopy analysis shows that no new electrically active defects are formed in the silicon bulk after annealing iron-containing silicon with silicon nitride films, confirming that the interstitial iron loss is not due to a change in the chemical structure of iron related defects in the silicon bulk. In addition, once the annealed silicon nitride films are removed, subsequent high temperature processes do not result in any reappearance of iron. Finally, the experimentally measured iron decay kinetics are shown to agree with a model of iron diffusion to the surface gettering sites, indicating a diffusion-limited iron gettering process for temperatures below 700 °C. The gettering process is found to become reaction-limited at higher temperatures.

  15. Porous silicon gettering

    SciTech Connect

    Tsuo, Y.S.; Menna, P.; Pitts, J.R.

    1996-05-01

    The authors have studied a novel extrinsic gettering method that uses the large surface areas produced by a porous-silicon etch as gettering sites. The annealing step of the gettering used a high-flux solar furnace. They found that a high density of photons during annealing enhanced the impurity diffusion to the gettering sites. The authors used metallurgical-grade Si (MG-Si) prepared by directional solidification casing as the starting material. They propose to use porous-silicon-gettered MG-Si as a low-cost epitaxial substrate for polycrystalline silicon thin-film growth.

  16. Lifetime prediction in vacuum packaged MEMS provided with integrated getter film

    NASA Astrophysics Data System (ADS)

    Siviero, Fabrizio; Bonucci, Antonio; Conte, Andrea; Moraja, Marco; Gigan, Olivier; Thomas, Isabelle

    2012-06-01

    Thin-film getter integration is one of the key technologies enabling the development of a wide class of MEMS devices, such as IR microbolometers and inertial sensors, where stringent vacuum requirements must be satisfied to achieve the desired performances and preserve them for the entire lifetime. Despite its importance, the question about lifetime prediction is still very difficult to answer in a reliable way. Here we present an experimental approach to the evaluation of lifetime, based on an accelerated life test performed varying both the storage conditions and the getter area. A test vehicle based on a resonator device was used. The hermeticity was evaluated by means of specific leak testing, while MEMS behavior during the ageing test was studied monitoring device functional parameters and by residual gas analysis (RGA). Unexpected results were observed leading to the discovery that methane is pumped by the getter below 100°C. These results served as the inputs of a suitable model allowing extrapolating the device lifetime in operating? conditions, and pointed out that RGA is an essential tool to correctly interpret the aging tests.

  17. Efficient combining of ion pumps and getter-palladium thin films

    SciTech Connect

    Paolini, C.; Mura, M.; Ravelli, F.

    2008-07-15

    Nonevaporable getters (NEGs) have been extensively studied in the last several years for their sorption properties toward many gases. In particular, an innovative alloy as a thin film by magnetron sputtering was developed and characterized at the European Organization for Nuclear Research. It is composed of Ti-Zr-V and protected by an overlayer of palladium (Pd), according to a technology for which the authors got the licence. NEG-Pd thin films used in combination with ion getter pumps is a simple, easy way to handle pumping devices for ultrahigh and extremely high vacuum applications. To show how to apply this coating technology to the internal surface of different types of ion pumps, the authors carried out several tests on pumps of various shapes, sizes (in terms of nominal pumping speed), and types (diode, noble diode, and triode). Special care was taken during the thermal cycle of baking and activation of the pumps to preserve the internal film from sources of contamination and/or from the sputtering of the titanium cathodes of the pump. Some important remarks will be made about the most appropriate conditions of pressure and temperature. The performance of the NEG-Pd-coated ion pumps was evaluated in terms of ultimate pressure and hydrogen pumping speed. The contribution of the thin film is particularly relevant for the pumping of this gas, due to its high sticking factor on palladium and the great sorption capacity of the underlying getter. Finally, the possibility of further improvement by substituting palladium with other Pd-based alloys will also be evaluated.

  18. Misfit dislocation gettering by substrate pit-patterning in SiGe films on Si(001)

    SciTech Connect

    Grydlik, Martyna; Groiss, Heiko; Brehm, Moritz; Schaeffler, Friedrich; Boioli, Francesca; Montalenti, Francesco; Miglio, Leo; Gatti, Riccardo; Devincre, Benoit

    2012-07-02

    We show that suitable pit-patterning of a Si(001) substrate can strongly influence the nucleation and the propagation of dislocations during epitaxial deposition of Si-rich Si{sub 1-x}Ge{sub x} alloys, preferentially gettering misfit segments along pit rows. In particular, for a 250 nm layer deposited by molecular beam epitaxy at x{sub Ge} = 15%, extended film regions appear free of dislocations, by atomic force microscopy, as confirmed by transmission electron microscopy sampling. This result is quite general, as explained by dislocation dynamics simulations, which reveal the key role of the inhomogeneous distribution in stress produced by the pit-patterning.

  19. Patterning of magnetic thin films and multilayers using nanostructured tantalum gettering templates.

    PubMed

    Qiu, Wenlan; Chang, Long; Lee, Dahye; Dannangoda, Chamath; Martirosyan, Karen; Litvinov, Dmitri

    2015-03-25

    This work demonstrates that a nonmagnetic thin film of cobalt oxide (CoO) sandwiched between Ta seed and capping layers can be effectively reduced to a magnetic cobalt thin film by annealing at 200 °C, whereas CoO does not exhibit ferromagnetic properties at room temperature and is stable at up to ∼400 °C. The CoO reduction is attributed to the thermodynamically driven gettering of oxygen by tantalum, similar to the exothermic reduction-oxidation reaction observed in thermite systems. Similarly, annealing at 200 °C of a nonmagnetic [CoO/Pd]N multilayer thin film sandwiched between Ta seed and Ta capping layers results in the conversion into a magnetic [Co/Pd]N multilayer, a material with perpendicular magnetic anisotropy that is of interest for magnetic data storage applications. A nanopatterning approach is introduced where [CoO/Pd]N multilayers is locally reduced into [Co/Pd]N multilayers to achieve perpendicular magnetic anisotropy nanostructured array. This technique can potentially be adapted to nanoscale patterning of other systems for which thermodynamically favorable combination of oxide and gettering layers can be identified.

  20. Impurity gettering

    SciTech Connect

    Picraux, S.T.

    1995-06-01

    Transition metal impurities are well known to cause detrimental effects when present in the active regions of Si devices. Their presence degrades minority carrier lifetime, provides recombination-generation centers, increases junction leakage current and reduces gate oxide integrity. Thus, gettering processes are used to reduce the available metal impurities from the active region of microelectronic circuits. Gettering processes are usually divided into intrinsic (or internal) and extrinsic (or external) categories. Intrinsic refers to processing the Si wafer in a way to make available internal gettering sites, whereas extrinsic implies externally introduced gettering sites. Special concerns have been raised for intrinsic gettering. Not only will the formation of the precipitated oxide and denuded zone be difficult to achieve with the lower thermal budgets, but another inherent limit may set in. In this or any process which relies on the precipitation of metal silicides the impurity concentration can only be reduced as low as the solid solubility limit. However, the solubilities of transition metals relative to silicide formation are typically found to be {approx_gt}10{sup 12}/cm{sup 3} at temperatures of 800 C and above, and thus inadequate to getter to the needed concentration levels. It is thus anticipated that future microelectronic device processing will require one or more of the following advances in gettering technology: (1) new and more effective gettering mechanisms; (2) quantitative models of gettering to allow process optimization at low process thermal budgets and metal impurity concentrations, and/or (3) development of front side gettering methods to allow for more efficient gettering close to device regions. These trend-driven needs provide a driving force for qualitatively new approaches to gettering and provide possible new opportunities for the use of ion implantation in microelectronics processing.

  1. Studies of chromium gettering

    SciTech Connect

    Simpkins, J.E.; Mioduszewski, P.; Stratton, L.W.

    1982-01-01

    Preliminary results have shown that hydrogen pumping by chromium is a surface effect. Unlike with titanium, the getter material used in many present day tokamaks, there is no significant diffusion into the bulk. Additional experiments have been carried out to measure the basic characteristics of chromium films for gases of interest in tokamak research. These gases include deuterium, oxygen and nitrogen. A vacuum system is described which allowed precise control of the test gas, a constant wall temperature and determination of the projected getter surface area. A quadrupole mass spectrometer, rather than simply a total pressure gauge, was utilized to measure the partial pressure of the test gas as well as the residual gas composition in the system. A quartz crystal monitor was used to measure film thickness. Pumping speeds and sticking coefficients are given as a function of surface coverage for each test gas. A comparison will be made with titanium films deposited in the same vacuum system and under similar conditions.

  2. Studies of chromium gettering

    NASA Astrophysics Data System (ADS)

    Simpkins, J. E.; Mioduszewski, P.; Stratton, L. W.

    1982-12-01

    Preliminary results have shown that hydrogen pumping by chromium is a surface effect. Unlike with titanium, the getter material used in many present day tokamaks, there is no significant diffusion into the bulk. This feature, which would minimize the tritium inventory, makes chromium a viable alternate to titanium gettering for future tokamaks. Additional experiments have been carried out to measure the basic characteristics of chromium films for gases of interest in tokamak research. These gases include deuterium, oxygen and nitrogen. A vacuum system is described which allowed precise control of the test gas, a constant wall temperature and determination of the projected getter surface area. A quadrupole mass spectrometer, rather than simply a total pressure gauge, was utilized to measure the partial pressure of the test gas as well as the residual gas composition in the system. A quartz crystal monitor was used to measure film thickness. Pumping speeds and sticking coefficients are given as a function of surface coverage for each test gas. A comparison will be made with titanium films deposited in the same vacuum system and under similar conditions.

  3. Porous silicon gettering

    SciTech Connect

    Tsuo, Y.S.; Menna, P.; Al-Jassim, M.

    1995-08-01

    We have studied a novel extrinsic gettering method that utilizes the very large surface areas, produced by porous silicon etch on both front and back surfaces of the silicon wafer, as gettering sites. In this method, a simple and low-cost chemical etching is used to generate the porous silicon layers. Then, a high-flux solar furnace (HFSF) is used to provide high-temperature annealing and the required injection of silicon interstitials. The gettering sites, along with the gettered impurities, can be easily removed at the end the process. The porous silicon removal process consists of oxidizing the porous silicon near the end the gettering process followed by sample immersion in HF acid. Each porous silicon gettering process removes up to about 10 {mu}m of wafer thickness. This gettering process can be repeated so that the desired purity level is obtained.

  4. Combination moisture and hydrogen getter

    DOEpatents

    Harrah, L.A.; Mead, K.E.; Smith, H.M.

    1983-09-20

    A combination moisture and hydrogen getter comprises (a) a moisture getter comprising a readily oxidizable metal; and (b) a hydrogen getter comprising (1) a solid acetylenic compound and (2) a hydrogenation catalyst. A method of scavenging moisture from a closed container uses the combination moisture and hydrogen getter to irreversibly chemically reduce the moisture and chemically bind the resultant hydrogen.

  5. Combination moisture and hydrogen getter

    DOEpatents

    Harrah, Larry A.; Mead, Keith E.; Smith, Henry M.

    1983-01-01

    A combination moisture and hydrogen getter comprises (a) a moisture getter comprising a readily oxidizable metal; and (b) a hydrogen getter comprising (i) a solid acetylenic compound and (ii) a hydrogenation catalyst. A method of scavenging moisture from a closed container uses the combination moisture and hydrogen getter to irreversibly chemically reduce the moisture and chemically bind the resultant hydrogen.

  6. Combination moisture and hydrogen getter

    DOEpatents

    Not Available

    1982-04-29

    A combination moisture and hydrogen getter comprises (a) a moisture getter comprising a readily oxidizable metal; and (b) a hydrogen getter comprising (i) a solid acetylenic compound and (ii) a hydrogenation catalyst. A method of scavenging moisture from a closed container uses the combination moisture and hydrogen getter to irreversibly chemically reduce the moisture and chemically bind the reusltant hydrogen.

  7. RENEWABLE LIQUID GETTERING PUMP

    DOEpatents

    Batzer, T.H.

    1962-08-21

    A method and structure were developed for pumping gases by simple absorption into a liquid gettering material. The invention comprises means ror continuously pumping a liquid getterrng material from a reservoir to the top of a generally vertical surface disposed in a vacuum pumping chamber to receive gaseous and other particles in the liquid gettering material which continuously flows downward over the vertical suiface. Means are provided for continuous removal, degassing, and return of a portion of the liquid gettering material from the reservoir connected with collectrng means at the base of the generally vertical plate. (AEC)

  8. Hydrogen gettering packing material, and process for making same

    DOEpatents

    LeMay, James D.; Thompson, Lisa M.; Smith, Henry Michael; Schicker, James R.

    2001-01-01

    A hydrogen gettering system for a sealed container is disclosed comprising packing material for use within the sealed container, and a coating film containing hydrogen gettering material on at least a portion of the surface of such packing material. The coating film containing the hydrogen gettering material comprises a mixture of one or more organic materials capable of reacting with hydrogen and one or more catalysts capable of catalyzing the reaction of hydrogen with such one or more organic materials. The mixture of one or more organic materials capable of reacting with hydrogen and the one or more catalysts is dispersed in a suitable carrier which preferably is a curable film-forming material. In a preferred embodiment, the packing material comprises a foam material which is compatible with the coating film containing hydrogen gettering material thereon.

  9. SAES St 909 Getter Testing at the Savannah River National Laboratory

    SciTech Connect

    Klein, J. E.; Holder, J. E

    2005-09-07

    Process gas tritium stripper technology has gone from catalytic oxidation followed by absorption on molecular sieve/zeolite beds to non-evaporate metal getter technology. SAES Getters produces a number of commercial getter products including St 909. St 909, a Zr-Mn-Fe alloy, is sold in pellet form, can decompose (''crack'') a number of process gas impurities, and retains lower levels of tritium than other getters. The performance of this material to remove process impurities, especially methane, under of variety of operating conditions has been part of a Savannah River National Laboratory (SRNL) for five years. St 909 has been tested at the bench (6 gram) scale, the pilot (500 gram) scale, and at the full (5300) gram scale under a variety of test conditions. This paper gives a brief summary of test results obtained for the different scale tests.

  10. Gettering Silicon Wafers with Phosphorus

    NASA Technical Reports Server (NTRS)

    Daiello, R. V.

    1983-01-01

    Silicon wafers subjected to gettering in phosphorus atmosphere have longer diffusion lengths and higher solar-cell efficiencies than untreated wafers. Gettering treatment improves properties of solar cells manufactured from impure silicon and is compatible with standard solar-cell processing.

  11. New High Capacity Getter for Vacuum-Insulated Mobile Liquid Hydrogen Storage Systems

    SciTech Connect

    H. Londer; G. R. Myneni; P. Adderley; G. Bartlok; J. Setina; W. Knapp; D. Schleussner

    2006-05-01

    Current ''Non evaporable getters'' (NEGs), based on the principle of metallic surface sorption of gas molecules, are important tools for the improving the performance of many vacuum systems. High porosity alloys or powder mixtures of Zr, Ti, Al, V, Fe and other metals are the base materials for this type of getters. The continuous development of vacuum technologies has created new challenges for the field of getter materials. The main sorption parameters of the current NEGs, namely, pumping speed and sorption capacity, have reached certain upper limits. Chemically active metals are the basis of a new generation of NEGs. The introduction of these new materials with high sorption capacity at room temperature is a long-awaited development. These new materials enable the new generation of NEGs to reach faster pumping speeds, significantly higher sticking rates and sorption capacities up to 104 times higher during their lifetimes. Our development efforts focus on producing these chemically active metals with controlled insulation or protection. The main structural forms of our new getter materials are spherical powders, granules and porous multi-layers. The full pumping performance can take place at room temperature with activation temperatures ranging from room temperature to 650 C. In one of our first pilot projects, our proprietary getter solution was successfully introduced as a getter pump in a double-wall mobile LH2 tank system. Our getters were shown to have very high sorption capacity of all relevant residual gases, including H2. This new concept opens the opportunity for significant vacuum improvements, especially in the field of H2 pumping which is an important task in many different vacuum applications.

  12. New High Capacity Getter for Vacuum-Insulated Mobile Liquid Hydrogen Storage Systems

    NASA Astrophysics Data System (ADS)

    Londer, H.; Myneni, G. R.; Adderley, P.; Bartlok, G.; Setina, J.; Knapp, W.; Schleussner, D.

    2006-05-01

    Current "Non evaporable getters" (NEGs), based on the principle of metallic surface sorption of gas molecules, are important tools for the improving the performance of many vacuum systems. High porosity alloys or powder mixtures of Zr, Ti, Al, V, Fe and other metals are the base materials for this type of getters. The continuous development of vacuum technologies has created new challenges for the field of getter materials. The main sorption parameters of the current NEGs, namely, pumping speed and sorption capacity, have reached certain upper limits. Chemically active metals are the basis of a new generation of NEGs. The introduction of these new materials with high sorption capacity at room temperature is a long-awaited development. These new materials enable the new generation of NEGs to reach faster pumping speeds, significantly higher sticking rates and sorption capacities up to 104 times higher during their lifetimes. Our development efforts focus on producing these chemically active metals with controlled insulation or protection. The main structural forms of our new getter materials are spherical powders, granules and porous multi-layers. The full pumping performance can take place at room temperature with activation temperatures ranging from room temperature to 650 °C. In one of our first pilot projects, our proprietary getter solution was successfully introduced as a getter pump in a double-wall mobile LH2 tank system. Our getters were shown to have very high sorption capacity of all relevant residual gases, including H2. This new concept opens the opportunity for significant vacuum improvements, especially in the field of H2 pumping which is an important task in many different vacuum applications.

  13. Impurity gettering in semiconductors

    DOEpatents

    Sopori, Bhushan L.

    1995-01-01

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500.degree. C. to about 700.degree. C. for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal.

  14. Impurity gettering in semiconductors

    DOEpatents

    Sopori, B.L.

    1995-06-20

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device is disclosed. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500 C to about 700 C for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal. 1 fig.

  15. Ionization-Assisted Getter Pumping for Ultra-Stable Trapped Ion Frequency Standards

    NASA Technical Reports Server (NTRS)

    Tjoelker, Robert L.; Burt, Eric A.

    2010-01-01

    A method eliminates (or recovers from) residual methane buildup in getter-pumped atomic frequency standard systems by applying ionizing assistance. Ultra-high stability trapped ion frequency standards for applications requiring very high reliability, and/or low power and mass (both for ground-based and space-based platforms) benefit from using sealed vacuum systems. These systems require careful material selection and system processing (cleaning and high-temperature bake-out). Even under the most careful preparation, residual hydrogen outgassing from vacuum chamber walls typically limits the base pressure. Non-evaporable getter pumps (NEGs) provide a convenient pumping option for sealed systems because of low mass and volume, and no power once activated. An ion gauge in conjunction with a NEG can be used to provide a low mass, low-power method for avoiding the deleterious effects of methane buildup in high-performance frequency standard vacuum systems.

  16. Low temperature, low pressure hydrogen gettering

    DOEpatents

    Anderson, D. Richard; Courtney, Robert L.; Harrah, Larry A.

    1976-06-15

    The invention relates to the gettering of hydrogen and its isotopes, the gettering materials being painted or coated onto, or otherwise disposed in an area or volume from which hydrogen is to be removed.

  17. Low temperature, low pressure hydrogen gettering

    DOEpatents

    Anderson, D.R.; Courtney, R.L.; Harrah, L.A.

    1975-07-22

    A system is described for the gettering of hydrogen and its isotopes. The gettering materials are painted or coated onto, or otherwise disposed in an area or volume from which hydrogen is to be removed. (auth)

  18. Copper in silicon: Quantitative analysis of internal and proximity gettering

    SciTech Connect

    McHugo, S.A.; Flink, C.; Weber, E.R.

    1997-08-01

    The behavior of copper in the presence of a proximity gettering mechanism and a standard internal gettering mechanism in silicon was studied. He implantation-induced cavities in the near surface region were used as a proximity gettering mechanism and oxygen precipitates in the bulk of the material provided internal gettering sites. Moderate levels of copper contamination were introduced by ion implantation such that the copper was not supersaturated during the anneals, thus providing realistic copper contamination/gettering conditions. Copper concentrations at cavities and internal gettering sites were quantitatively measured after the annealings. In this manner, the gettering effectiveness of cavities was measured when in direct competition with internal gettering sites. The cavities were found to be the dominant gettering mechanism with only a small amount of copper gettered at the internal gettering sites. These results reveal the benefits of a segregation-type gettering mechanism for typical contamination conditions.

  19. Method for charging a hydrogen getter

    DOEpatents

    Tracy, C. Edwin; Keyser, Matthew A.; Benson, David K.

    1998-01-01

    A method for charging a sample of either a permanent or reversible getter material with a high concentration of hydrogen while maintaining a base pressure below 10.sup.-4 torr at room temperature involves placing the sample of hydrogen getter material in a chamber, activating the sample of hydrogen getter material, overcharging the sample of getter material through conventional charging techniques to a high concentration of hydrogen, and then subjecting the sample of getter material to a low temperature vacuum bake-out process. Application of the method results in a reversible hydrogen getter which is highly charged to maximum capacities of hydrogen and which concurrently exhibits minimum hydrogen vapor pressures at room temperatures.

  20. Method for charging a hydrogen getter

    DOEpatents

    Tracy, C.E.; Keyser, M.A.; Benson, D.K.

    1998-09-15

    A method for charging a sample of either a permanent or reversible getter material with a high concentration of hydrogen while maintaining a base pressure below 10{sup {minus}4} torr at room temperature involves placing the sample of hydrogen getter material in a chamber, activating the sample of hydrogen getter material, overcharging the sample of getter material through conventional charging techniques to a high concentration of hydrogen, and then subjecting the sample of getter material to a low temperature vacuum bake-out process. Application of the method results in a reversible hydrogen getter which is highly charged to maximum capacities of hydrogen and which concurrently exhibits minimum hydrogen vapor pressures at room temperatures. 9 figs.

  1. Aluminum gettering in single and multicrystalline silicon

    SciTech Connect

    McHugo, S.A.; Hieslmair, H.; Weber, E.R.

    1995-08-01

    Al gettering has been performed on integrated circuit (I.C.) quality silicon and a variety of single and multicrystalline silicon solar cell materials. The minority carrier diffusion length, Ln, has been used to quantify the gettering response. Vast differences in response to the Al gettering treatment are observed between the I.C. quality silicon and the solar cell materials. The I.C. silicon generally responds well while the solar cell silicon performance progressively degrades with increasing gettering temperature. Preliminary data shows that by performing a Rapid Thermal Annealing treatment prior to the Al gettering, an improved or further degraded Ln emerges in solar cell material depending on the material`s manufacturer. We explain these observed phenomena by suggesting that Al gettering in solar cell silicon is an impurity emission-limited process while for I.C. quality silicon it is diffusion limited.

  2. Oxidation resistant organic hydrogen getters

    DOEpatents

    Shepodd, Timothy J.; Buffleben, George M.

    2008-09-09

    A composition for removing hydrogen from an atmosphere, comprising a mixture of a polyphenyl ether and a hydrogenation catalyst, preferably a precious metal catalyst, and most preferably Pt. This composition is stable in the presence of oxygen, will not polymerize or degrade upon exposure to temperatures in excess of 200.degree. C., or prolonged exposure to temperatures in the range of 100-300.degree. C. Moreover, these novel hydrogen getter materials can be used to efficiently removing hydrogen from mixtures of hydrogen/inert gas (e.g., He, Ar, N.sub.2), hydrogen/ammonia atmospheres, such as may be encountered in heat exchangers, and hydrogen/carbon dioxide atmospheres. Water vapor and common atmospheric gases have no adverse effect on the ability of these getter materials to absorb hydrogen.

  3. Polymer system for gettering hydrogen

    DOEpatents

    Shepodd, Timothy Jon; Whinnery, LeRoy L.

    2000-01-01

    A novel composition comprising organic polymer molecules having carbon-carbon double bonds, for removing hydrogen from the atmosphere within enclosed spaces. Organic polymers molecules containing carbon-carbon double bonds throughout their structures, preferably polybutadiene, polyisoprene and derivatives thereof, intimately mixed with an insoluble catalyst composition, comprising a hydrogenation catalyst and a catalyst support, preferably Pd supported on carbon, provide a hydrogen getter composition useful for removing hydrogen from enclosed spaces even in the presence of contaminants such as common atmospheric gases, water vapor, carbon dioxide, ammonia, oil mists, and water. The hydrogen getter composition disclosed herein is particularly useful for removing hydrogen from enclosed spaces containing potentially explosive mixtures of hydrogen and oxygen.

  4. Polymer formulations for gettering hydrogen

    DOEpatents

    Shepodd, Timothy Jon; Whinnery, LeRoy L.

    1998-11-17

    A novel composition comprising organic polymer molecules having carbon-carbon double bonds, for removing hydrogen from the atmosphere within enclosed spaces. Organic polymers molecules containing carbon-carbon double bonds throughout their structures, preferably polybutadiene, polyisoprene and derivatives thereof, intimately mixed with an insoluble catalyst composition, comprising a hydrogenation catalyst and a catalyst support, preferably Pd supported on carbon, provide a hydrogen getter composition useful for removing hydrogen from enclosed spaces even in the presence of contaminants such as common atmospheric gases, water vapor, carbon dioxide, ammonia, oil mists, and water. The hydrogen getter composition disclosed herein is particularly useful for removing hydrogen from enclosed spaces containing potentially explosive mixtures of hydrogen and oxygen.

  5. Polymer formulations for gettering hydrogen

    DOEpatents

    Shepodd, T.J.; Whinnery, L.L.

    1998-11-17

    A novel composition is described comprising organic polymer molecules having carbon-carbon double bonds, for removing hydrogen from the atmosphere within enclosed spaces. Organic polymers molecules containing carbon-carbon double bonds throughout their structures, preferably polybutadiene, polyisoprene and derivatives thereof, intimately mixed with an insoluble catalyst composition, comprising a hydrogenation catalyst and a catalyst support, preferably Pd supported on carbon, provide a hydrogen getter composition useful for removing hydrogen from enclosed spaces even in the presence of contaminants such as common atmospheric gases, water vapor, carbon dioxide, ammonia, oil mists, and water. The hydrogen getter composition disclosed herein is particularly useful for removing hydrogen from enclosed spaces containing potentially explosive mixtures of hydrogen and oxygen. 1 fig.

  6. Hydrogen isotope separation utilizing bulk getters

    DOEpatents

    Knize, R.J.; Cecchi, J.L.

    1991-08-20

    Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen. 4 figures.

  7. Hydrogen isotope separation utilizing bulk getters

    DOEpatents

    Knize, Randall J.; Cecchi, Joseph L.

    1990-01-01

    Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen.

  8. Hydrogen isotope separation utilizing bulk getters

    DOEpatents

    Knize, Randall J.; Cecchi, Joseph L.

    1991-01-01

    Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen.

  9. Hydrogen isotope separation utilizing bulk getters

    SciTech Connect

    Knize, R.J.; Cecchi, J.L.

    1990-12-11

    This patent describes hydrogen isotope separation utilizing bulk getters. Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen.

  10. Treatment of waste water in non-evaporating dehydration of low grade coal

    SciTech Connect

    Nakabayashi, Y.; Kamei, T.; Komai, K.; Kurihara, M.; Matsuura, Y.; Nakamura, A.; Shimotamari, A.; Wakabayashi, T.

    1983-07-26

    In a non-evaporating dehydration of brown coal, the coal is crushed and classified into lumps and fine particles. The lumps of coal are subjected to a non-evaporating dehydration in which waste water is produced. The waste water is contacted with the fine particles of coal so that components which affect the COD value of the water are absorbed by the coal particles. The coal particles are then burnt to produce saturated steam which is used in the non-evaporating dehydration.

  11. Internal gettering by metal alloy clusters

    DOEpatents

    Buonassisi, Anthony; Heuer, Matthias; Istratov, Andrei A.; Pickett, Matthew D.; Marcus, Mathew A.; Weber, Eicke R.

    2010-07-27

    The present invention relates to the internal gettering of impurities in semiconductors by metal alloy clusters. In particular, intermetallic clusters are formed within silicon, such clusters containing two or more transition metal species. Such clusters have melting temperatures below that of the host material and are shown to be particularly effective in gettering impurities within the silicon and collecting them into isolated, less harmful locations. Novel compositions for some of the metal alloy clusters are also described.

  12. Gettering of metal impurities in silicon

    SciTech Connect

    Schroeter, W.; Spiecker, E.; Apel, M.

    1995-08-01

    Gettering means the removal of metallic impurities from the device-active area of the wafer by transport to a predesigned region-called gettering layer (GL). We introduce an interface at z = d{sub GL}, at which the effect of the gettering mechanism on the metal impurity distribution in the wafer is quantified, e.g. by specifying currents or by interfacial reactions of metal impurities, self interstitials etc. between GL and wafer. In response metal impurities will diffuse out of the wafer into the gettering layer. Following such a concept, in general three species of the metal impurity (M) are involved in gettering: M{sub p} {l_arrow} M{sub i} {l_arrow} M{sub GL}. M{sub p} denotes immobile species in the wafer, which are precipitated into suicides or segregated at extended defects or whose diffusivity is too small to contribute noticeably to transport during the gettering procedure - like many substitutional metal species.

  13. Development of a Prototype Optical Hydrogen Gas Sensor Using a Getter-Doped Polymer Transducer for Monitoring Cumulative Exposure: Preliminary Results

    SciTech Connect

    Small IV, W; Maitland, D J; Wilson, T S; Bearinger, J P; Letts, S A; Trebes, J E

    2008-06-05

    A novel prototype optical sensor for monitoring cumulative hydrogen gas exposure was fabricated and evaluated. Chemical-to-optical transduction was accomplished by detecting the intensity of 670 nm laser light transmitted through a hydrogen getter-doped polymer film mounted at the end of an optical fiber; the transmittance of the composite film increased with uptake of hydrogen by the embedded getter. The composite film consisted of the hydrogen getter 1,4-bis(phenylethynyl)benzene, also known as DEB, with carbon-supported palladium catalyst embedded in silicone elastomer. Because the change in transmittance was irreversible and occurred continuously as the getter captured hydrogen, the sensor behaved like a dosimeter, providing a unique indication of the cumulative gas exposure.

  14. Toward understanding and modeling of impurity gettering in silicon

    SciTech Connect

    Tan, Teh Y.; Gafiteanu, R.; Goesele, U.M.

    1995-08-01

    Gettering of harmful impurities away from the device active regions has already become an integral part of manufacturing integrated circuits (IC) using Czochralski (CZ) Si wafers, and is experiencing an increasing importance in Si solar cell fabrications for improving the cell efficiency. Gettering consists of (1) the creation of suitable gettering sites; and (2) the gettering processes of contaminants. Requirements for successful gettering differ between the IC and solar cell cases, because ICs are monolithic devices situated at the Si wafer surfaces while solar cells are bulk devices, and because the Si substrate materials used are different. For IC fabrications, the method used is that of intrinsic or internal gettering (IG) which utilizes oxygen precipitates and their associated defects in the CZ Si wafer bulk as gettering sites. Because of the bulk nature of IG sites, the scheme cannot be used also for solar cells. Only some kind of extrinsic or external gettering (EG) schemes with gettering sites located at the wafer surface regions can be used for solar cells. The gettering of the harmful contaminants, usually metals, to the gettering region involves the metal dissolution from precipitated state, the metal atom diffusion to and the stabilization at the gettering sites. A mathematical model of the gettering process is presented.

  15. Mechanisms of transition-metal gettering in silicon

    SciTech Connect

    MYERS JR.,SAMUEL M.; SEIBT,M.; SCHROTER,W.

    2000-03-23

    The atomic process, kinetics, and equilibrium thermodynamics underlying the gettering of transition-metal impurities in Si are reviewed from a mechanistic perspective. Methods for mathematical modeling of gettering are reviewed and illustrated. Needs for further research are discussed.

  16. Hydrogen Uptake of DPB Getter Pellets

    SciTech Connect

    Dinh, L N; Schildbach, M A; Herberg, J L; Saab, A P; Weigle, J; Chinn, S C; Maxwell, R S; McLean II, W

    2008-05-30

    The physical and chemical properties of 1,4-diphenylbutadiyne (DPB) blended with carbon-supported Pd (DPB-Pd/C) in the form of pellets during hydrogenation were investigated. A thermogravimetric analyzer (TGA) was employed to measure the kinetics of the hydrogen uptake by the DPB getter pellets. The kinetics obtained were then used to develop a semi-empirical model, based on gas diffusion into solids, to predict the performance of the getter pellets under various conditions. The accuracy of the prediction model was established by comparing the prediction models with independent experimental data on hydrogen pressure buildup in sealed systems containing DPB getter pellets and subjected to known rates of hydrogen input. The volatility of the hydrogenated DPB products and its effects on the hydrogen uptake kinetics were also analyzed.

  17. Dominant factors of the laser gettering of silicon wafers

    SciTech Connect

    Bokhan, Yu. I. E-mail: yuibokhan@gmail.com; Kamenkov, V. S.; Tolochko, N. K.

    2015-02-15

    The laser gettering of silicon wafers is experimentally investigated. The typical gettering parameters are considered. The surfaces of laser-treated silicon wafers are investigated by microscopy. When studying the effect of laser radiation on silicon wafers during gettering, a group of factors determining the conditions of interaction between the laser beam and silicon-wafer surface and affecting the final result of treatment are selected. The main factors determining the gettering efficiency are revealed. Limitations on the desired value of the getter-layer capacity on surfaces with insufficiently high cleanness (for example, ground or matte) are established.

  18. Hydrogen and moisture getter and absorber for sealed devices

    DOEpatents

    Smith, H.M.; Schicker, J.R.

    1999-03-30

    The present invention is a hydrogen getter and method for formulating and using the getter. This getter effectively removes hydrogen gas typically present in many hermetically-sealed electronic applications where the presence of such gas would otherwise be harmful to the electronics. The getter is a non-organic composition, usable in a wide range of temperatures as compared to organic getters. Moreover, the getter is formulated to be used without the need for the presence of oxygen. The getter is comprised of effective amounts of an oxide of a platinum group metal, a desiccant, and a gas permeable binder which preferably is cured after composition in an oxygen-bearing environment at about 150 to about 205 degrees centigrade.

  19. Absorption media for irreversibly gettering thionyl chloride

    DOEpatents

    Buffleben, George; Goods, Steven H.; Shepodd, Timothy; Wheeler, David R.; Whinnery, Jr., LeRoy

    2002-01-01

    Thionyl chloride is a hazardous and reactive chemical used as the liquid cathode in commercial primary batteries. Contrary to previous thinking, ASZM-TEDA.RTM. carbon (Calgon Corporation) reversibly absorbs thionyl chloride. Thus, several candidate materials were examined as irreversible getters for thionyl chloride. The capacity, rate and effect of temperature were also explored. A wide variety of likely materials were investigated through screening experiments focusing on the degree of heat generated by the reaction as well as the material absorption capacity and irreversibility, in order to help narrow the group of possible getter choices. More thorough, quantitative measurements were performed on promising materials. The best performing getter was a mixture of ZnO and ASZM-TEDA.RTM. carbon. In this example, the ZnO reacts with thionyl chloride to form ZnCl.sub.2 and SO.sub.2. The SO.sub.2 is then irreversibly gettered by ASZM-TEDA.RTM. carbon. This combination of ZnO and carbon has a high capacity, is irreversible and functions effectively above -20.degree. C.

  20. Technetium getters in the near surface environment

    SciTech Connect

    KRUMHANSL,JAMES L.; ZHANG,PENGCHU; WESTRICH,HENRY R.; BRYAN,CHARLES R.; MOLECKE,MARTIN A.

    2000-05-19

    Conventional performance assessments assume that radioactive {sup 99}Tc travels as a non-sorbing component with an effective K{sub d} (distribution coefficient) of 0. This is because soil mineral surfaces commonly develop net negative surface charges and pertechnetate (TcO{sub 4}), with large ionic size and low electrical density, is not sorbed onto them. However, a variety of materials have been identified that retain Tc and may eventually lead to promising Tc getters. In assessing Tc getter performance it is important to evaluate the environment in which the getter is to function. In many contaminant plumes Tc will only leach slowly from the source of the contamination and significant dilution is likely. Thus, sub-ppb Tc concentrations are expected and normal groundwater constituents will dominate the aquifer chemistry. In this setting a variety of constituents were found to retard TcO{sub 4}: imogolite, boehmite, hydrotalcite, goethite, copper sulfide and oxide and coal. Near leaking tanks of high level nuclear waste, Tc may be present in mg/L level concentrations and groundwater chemistry will be dominated by constituents from the waste. Both bone char, and to a lesser degree, freshly precipitated Al hydroxides may be effective Tc scavengers in this environment. Thus, the search for Tc getters is far from hopeless, although much remains to be learned about the mechanisms by which these materials retain Tc.

  1. The use of synthetic hydrocalcite as a chloride-ion getter for a barrier aluminum anodization process

    SciTech Connect

    Panitz, J.K.G.; Sharp, D.J.

    1995-11-01

    Chloride ion contamination at parts per billion concentrations plaques electrochemists studying barrier anodic aluminum oxide film growth and anodic aluminum oxide capacitor manufacturers. Chloride ion contamination slows film growth and reduces film quality. We have demonstrated that synthetic hydrocalcite substantially reduces the detrimental effects of chloride ion contamination in an aqueous electrolyte commonly used to grow barrier anodic aluminum oxide. We have determined that problems arise if precautions are not taken when using synthetic hydrocalcite as a chloride-ion getter in an aqueous electrolyte. Synthetic hydrocalcite is somewhat hydrophobic. If this powder is added directly to an aqueous electrolyte, some powder disperses; some floats to the top of the bath and forms scum that locally impedes anodic film formation. Commercially available powder contains a wide range of particle sizes including submicrometer-sized particles that can escape through filters into the electrolyte and cause processing problems. These problems can be over come if (1) the getter is placed in filter bags, (2) a piece of filter paper is used to skim trace amounts of getter floating on the top of the bath, (3) dummy runs are performed to scavenge chloride-ion loaded getter micelles dispersed in the bath, and (4) substrates are rinsed with a strong stream of deionized water to remove trace amounts of powder after anodization.

  2. Copper gettering by aluminum precipitates in aluminum-implanted silicon

    SciTech Connect

    PETERSEN,GARY A.; MYERS JR.,SAMUEL M.

    2000-03-20

    Copper in Si is shown to be strongly gettered by Al-rich precipitates formed by implanting Al to supersaturation and followed by annealing. At temperatures ranging from 600 to 800 C a layer containing Al precipitates is found to getter Cu from Cu silicide located on the opposite side of a 0.25-mm Si wafer, indicating a substantially lower chemical potential for the Cu in the molten-A1 phase. Cu gettering proceeds rapidly until an atomic ratio of approximately 2 Cu atoms to 1 Al atom is reached in the precipitated Al region, after which the gettering process slows. Redistribution of Cu from one Al-rich layer to another at low Cu concentrations demonstrates that a segregation-type gettering mechanism is operating. Cu gettering occurs primarily in the region containing the precipitated Al rather than the region where the Al is entirely substitutional.

  3. Getter pump for hydrogen and hydrocarbon gases

    DOEpatents

    Hsu, Wen Ling

    1987-10-14

    A gettering device for hydrogen isotopes and gaseous hydrocarbons based on the interaction of a plasma and graphite used as cathodic material. The plasma is maintained at a current density within the range of about 1 to about 1000 mA/cm/sup 2/. The graphite may be heated to a temperature greater than 1000/degree/C. The new device offers high capacity, low noise, and gas species selectivity. 2 figs.

  4. Getter pump for hydrogen and hydrocarbon gases

    DOEpatents

    Hsu, Wen L.

    1989-01-01

    A gettering device for hydrogen isotopes and gaseous hydrocarbons based on the interaction of a plasma and graphite used as cathodic material. The plasma is maintained at a current density within the range of about 1 to about 1000 mA/cm.sup.2. The graphite may be heated to a temperature greater than 1000.degree. C. The new device offers high capacity, low noise, and gas species selectivity.

  5. Modeling phosphorus diffusion gettering of iron in single crystal silicon

    NASA Astrophysics Data System (ADS)

    Haarahiltunen, A.; Savin, H.; Yli-Koski, M.; Talvitie, H.; Sinkkonen, J.

    2009-01-01

    We propose a quantitative model for phosphorus diffusion gettering (PDG) of iron in silicon, which is based on a special fitting procedure to experimental data. We discuss the possibilities of the underlying physics of the segregation coefficient. Finally, we show that the proposed PDG model allows quantitative analysis of gettering efficiency of iron at various processing conditions.

  6. Mechanisms of transition-metal gettering in silicon

    SciTech Connect

    Myers, S. M.; Seibt, M.; Schroeter, W.

    2000-10-01

    The atomic process, kinetics, and equilibrium thermodynamics underlying the gettering of transition-metal impurities in Si are reviewed. Methods for mathematical modeling of gettering are discussed and illustrated. Needs for further research are considered. (c) 2000 American Institute of Physics.

  7. Rain scavenging of soluble gases by non-evaporating and evaporating droplets from inhomogeneous atmosphere

    NASA Astrophysics Data System (ADS)

    Elperin, Tov; Fominykh, Andrew; Krasovitov, Boris

    2013-11-01

    We suggest a one-dimensional model of precipitation scavenging of soluble gaseous pollutants by non-evaporating and evaporating droplets that is valid for arbitrary initial vertical distribution of soluble trace gases in the atmosphere. It is shown that for low gradients of soluble trace gases in the atmosphere, scavenging of gaseous pollutants is governed by a linear wave equation that describes propagation of a wave in one direction. The derived equation is solved by the method of characteristics. Scavenging coefficient and the rates of precipitation scavenging are calculated for wet removal of sulfur dioxide (SO2) and ammonia (NH3) using measured initial distributions of trace gases. It is shown that scavenging coefficient for arbitrary initial vertical distribution of soluble trace gases in the atmosphere is non-stationary and height-dependent. In case of exponential initial distribution of soluble trace gases in the atmosphere, scavenging coefficient for non-evaporating droplets in the region between the ground and the position of a scavenging front is a product of rainfall rate, solubility parameter, and the growth constant in the formula for the initial profile of a soluble trace gas in the atmosphere. This expression yields the same estimate of scavenging coefficient for sulfur dioxide scavenging by rain as field estimates presented in McMahon and Denison (1979). It is demonstrated that the smaller the slope of the concentration profile the higher the value of a scavenging coefficient.

  8. Electrolytic gettering of tritium from air

    SciTech Connect

    Souers, P.C.; Tsugawa, R.T.; Stevens, C.G.

    1983-01-01

    We have removed 90% of 1 part-per-million tritium gas in air of 25% to 35% humidity by the dc electrical action of the solid proton electrolyte hydrogen uranyl phosphate (HUP). Gettering takes 5 to 24 hours for a 1 cm/sup 2/ HUP disc at 2 to 4 V in a static, 1200 cc gas volume. Hydrogen gas may be used to flush captured tritium through the HUP. Liquid water leaches out the tritium but water vapor is ineffective. This technique promises an alternative to the conventional catalyst/zeolite method.

  9. Eulerian CFD modeling and X-ray validation of non-evaporating diesel spray

    NASA Astrophysics Data System (ADS)

    Xue, Qingluan; Som, Sibendu; Quan, Shaoping; Pomraning, Eric; Senecal, P. K.

    2013-11-01

    This work implemented an Eulerian single-phase approach by Vallet et al. into CFD software (Convergent) for diesel spray simulations. This Eulerian approach considers liquid and gas phase as a complex mixture of a single flow with a highly variable density to describe the near nozzle dense sprays. The mean density is obtained form the Favre-averaged liquid mass fraction. Liquid mass fraction is transported with a model for the turbulent liquid diffusion flux into the gas. A mean gradient-based model is employed for the diffusion flux in this study. A non-evaporating diesel spray was measured using x-ray radiography at Argonne National Laboratory. The quantitative and time-resolved data of liquid penetration and mass distribution in the dense spray region are used to validate this approach. The different turbulence models are also used for the simulations. The comparison between the simulated results and experimental data and the turbulence model effect are discussed.

  10. Modeling boron diffusion gettering of iron in silicon solar cells

    NASA Astrophysics Data System (ADS)

    Haarahiltunen, A.; Talvitie, H.; Savin, H.; Yli-Koski, M.; Asghar, M. I.; Sinkkonen, J.

    2008-01-01

    In this paper, a model is presented for boron diffusion gettering of iron in silicon during thermal processing. In the model, both the segregation of iron due to high boron doping concentration and heterogeneous precipitation of iron to the surface of the wafer are taken into account. It is shown, by comparing simulated results with experimental ones, that this model can be used to estimate boron diffusion gettering efficiency of iron under a variety of processing conditions. Finally, the application of the model to phosphorus diffusion gettering is discussed.

  11. Transient getter scheme for the tokamak fusion test reactor

    NASA Astrophysics Data System (ADS)

    Cecchi, J. L.; Cohen, S. A.; Sredniawski, J. J.

    1980-02-01

    A method has been developed of utilizing SAES Zr/Al getter modules, which obviates the need for frequent interruptions of machine operation by using the pulsed operation of TFTR. These interruptions are required for regeneration of the absorbed tritium after as few as 50 machine pulses. With the Zr/Al getter at 500-600 C it is possible to achieve a quasisteady state in tritium loading where the quantity of tritium desorbed between pulses is equal to the quantity which is absorbed during a pulse. Since frequent thermal cycling is not required, this scheme also reduces the possibility of Zr/Al getter material fatigue.

  12. Phosphorus and boron diffusion gettering of iron in monocrystalline silicon

    NASA Astrophysics Data System (ADS)

    Talvitie, H.; Vähänissi, V.; Haarahiltunen, A.; Yli-Koski, M.; Savin, H.

    2011-05-01

    We have studied experimentally the phosphorus diffusion gettering (PDG) of iron in monocrystalline silicon at the temperature range of 650-800 °C. Our results fill the lack of data at low temperatures so that we can obtain a reliable segregation coefficient for iron between a phosphorus diffused layer and bulk silicon. The improved segregation coefficient is verified by time dependent PDG simulations. Comparison of the PDG to boron diffusion gettering (BDG) in the same temperature range shows PDG to be only slightly more effective than BDG. In general, we found that BDG requires more carefully designed processing conditions than PDG to reach a high gettering efficiency.

  13. User’s Guide for Getter Rate Test System

    SciTech Connect

    Elmore, Monte R.

    2007-06-27

    This User’s Guide describes the operation and maintenance of the Getter Rate Test System, including the mechanical equipment, instrumentation, and datalogger/computer components. The Getter Rate Test System includes equipment and instrumentation to conduct two getter rate tests simultaneously. The mechanical equipment comprises roughing and high-vacuum pumps, heated test chambers, standard hydrogen leaks, and associated piping and valves. Instrumentation includes thermocouples, pressure (vacuum) transducers, panel displays, analog-to-digital signal converter, and associated wiring. The datalogger/computer is a stand-alone computer with installed software to allow the user to record data input from the pressure transducers to data files and to calculate the getter rate from the data in an Excel® spreadsheet.

  14. Technetium Getters to Improve Cast Stone Performance

    SciTech Connect

    Neeway, James J.; Lawter, Amanda R.; Serne, R. Jeffrey; Asmussen, Robert M.; Qafoku, Nikolla

    2015-10-15

    The cementitious material known as Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. Two radionuclides of particular concern in these waste streams are technetium-99 (99Tc) and iodine-129 (129I). These radioactive tank waste components contribute the most to the environmental impacts associated with the cleanup of the Hanford site. A recent environmental assessment of Cast Stone performance, which assumes a diffusion controlled release of contaminants from the waste form, calculates groundwater in excess of the allowable maximum permissible concentrations for both contaminants. There is, therefore, a need and an opportunity to improve the retention of both 99Tc and 129I in Cast Stone. One method to improve the performance of Cast Stone is through the addition of “getters” that selectively sequester Tc and I, therefore reducing their diffusion out of Cast Stone. In this paper, we present results of Tc and I removal from solution with various getters with batch sorption experiments conducted in deionized water (DIW) and a highly caustic 7.8 M Na Ave LAW simulant. In general, the data show that the selected getters are effective in DIW but their performance is comprised when experiments are performed with the 7.8 M Na Ave LAW simulant. Reasons for the mitigated performance in the LAW simulant may be due to competition with Cr present in the 7.8 M Na Ave LAW simulant and to a pH effect.

  15. Development of hydrogen gas getters for TRU waste

    SciTech Connect

    Kaszuba, J. P.; Mroz, E. J.; Peterson, E.; Stone, M.; Haga, M. J.

    2004-01-01

    Alpha radiolysis of hydrogenous waste and packaging materials generates hydrogen gas in radioactive storage containers. For this reason, the flammable gas (hydrogen) concentration in waste shipment containers (Transuranic Package Transporter-II or TP-II containers) is limited to the lower explosion limit of hydrogen in air (5 vol%). The use of hydrogen getters is being investigated to prevent the build up of hydrogen during storage and transport of the TP-II containers (up to 60 days). Preferred hydrogen getters are solid materials that scavenge hydrogen from the gas phase and chemically and irreversibly bind it in the solid state. One proven getter, 1,4-bis(phenylethynyl)benzene or DEB, belongs to a class of compounds called alkynes, which are characterized by the presence of carbon-carbon triple bonds. These carbon atoms will, in the presence of suitable catalysts such as palladium, irreversibly react with hydrogen to form the corresponding saturated alkane compounds. Because DEB contains two triple bonds, one mole of DEB reacts with 4 moles of hydrogen. The standard formulation for the 'DEB getter' is a mixture of 75% DEB and 25% carbon catalyst (5% palladium on carbon). Certain chemicals such as volatile organic compounds (VOCs) are known to 'poison' and reduce the activity of the catalyst. Therefore, in addition to the standard formulation, a semi-permeable barrier that encapsulates and protects the getter and its catalyst from poisons was also developed. The uncoated and polymer coated getter formulations were subjected to tests that determined the performance of the getters with regard to capacity, operating temperature range (with hydrogen in nitrogen and in air), hydrogen concentration, poisons, aging, pressure, reversibility, and radiation effects. This testing program was designed to address the following performance requirements: (1) Minimum rate for hydrogen removal of 1.2E-5 moles hydrogen per second for 60 days; (2) Sufficient getter material within

  16. Getters for Tc and I Removal from Liquid Waste

    NASA Astrophysics Data System (ADS)

    Qafoku, N. P.; Asmussen, M.; Lawter, A.; Neeway, J.; Smith, G.

    2015-12-01

    A cementitious waste form, Cast Stone, is being evaluated as a possible supplemental waste form for the low activity waste (LAW) at the Hanford Site, which contains significant amounts of radioactive 99Tc and 129I, as part of the tank waste cleanup mission. To improve the retention of Tc and/or I in Cast Stone, materials with a high affinity for Tc and/or I, termed "getters," can be added to decrease the rate of contaminant release and diffusivity, and improve Cast Stone performance. A series of kinetic batch sorption experiments was performed to determine the effectiveness of the getter materials. Several Tc getters [blast furnace slag, Sn (II) apatite, SnCl2, nanoporous Sn phosphate, KMS-2 (a potassium-metal-sulfide), and Sn(II) hydroxyapatite] and I getters [layered Bi hydroxide, natural argentite mineral, synthetic argentite, Ag-impregnated carbon, and Ag-exchanged zeolite] were tested in different solution media, 18.2 MΩ DI H2O and a caustic LAW waste simulant containing 6.5 M Na or 7.8 M Na. The experiments were conducted at room temperature in the presence or absence of air. Results indicated that most Tc getters (with the exception of KMS-2) performed better in the DI H2O solution than in the 6.5 and 7.8 M Na LAW simulant. In addition, Tc sequestration may be affected by the presence of other redox sensitive elements that were present in the LAW simulant, such as Cr. The Tc getter materials have been examined through various solid-state characterization techniques such as XRD, SEM/EDS, XANES and EXAFS which provided evidence for plausible mechanisms of aqueous Tc removal. The results indicated that the Tc precipitates differ depending on the getter material and that Tc(VII) is reduced to Tc(IV) in most of the getters but to a differing extents. For the I getters, Ag-exchanged zeolite and synthetic argentite were the most effective ones. The other I getters showed limited effectiveness for sorbing I under the high ionic strength and caustic

  17. Non-evaporative effects of a wet mid layer on heat transfer through protective clothing.

    PubMed

    Bröde, Peter; Havenith, George; Wang, Xiaoxin; Candas, Victor; den Hartog, Emiel A; Griefahn, Barbara; Holmér, Ingvar; Kuklane, Kalev; Meinander, Harriet; Nocker, Wolfgang; Richards, Mark

    2008-09-01

    In order to assess the non-evaporative components of the reduced thermal insulation of wet clothing, experiments were performed with a manikin and with human subjects in which two layers of underwear separated by an impermeable barrier were worn under an impermeable overgarment at 20 degrees C, 80% RH and 0.5 ms(-1) air velocity. By comparing manikin measurements with dry and wetted mid underwear layer, the increase in heat loss caused by a wet layer kept away from the skin was determined, which turned out to be small (5-6 W m(-2)), irrespective of the inner underwear layer being dry or wetted, and was only one third of the evaporative heat loss calculated from weight change, i.e. evaporative cooling efficiency was far below unity. In the experiments with eight males, each subject participated in two sessions with the mid underwear layer either dry or wetted, where they stood still for the first 30 min and then performed treadmill work for 60 min. Reduced heat strain due to lower insulation with the wetted mid layer was observed with decreased microclimate and skin temperatures, lowered sweat loss and cardiac strain. Accordingly, total clothing insulation calculated over the walking period from heat balance equations was reduced by 0.02 m(2) degrees C W(-1) (16%), while for the standing period the same decrease in insulation, representing 9% reduction only showed up after allowing for the lower evaporative cooling efficiency in the calculations. As evaporation to the environment and inside the clothing was restricted, the observed small alterations may be attributed to the wet mid layer's increased conductivity, which, however, appears to be of minor importance compared to the evaporative effects in the assessment of the thermal properties of wet clothing.

  18. Improved Hydrogen Gas Getters for TRU Waste -- Final Report

    SciTech Connect

    Mark Stone; Michael Benson; Christopher Orme; Thomas Luther; Eric Peterson

    2005-09-01

    Alpha radiolysis of hydrogenous waste and packaging materials generates hydrogen gas in radioactive storage containers. For that reason, the Nuclear Regulatory Commission limits the flammable gas (hydrogen) concentration in the Transuranic Package Transporter-II (TRUPACT-II) containers to 5 vol% of hydrogen in air, which is the lower explosion limit. Consequently, a method is needed to prevent the build up of hydrogen to 5 vol% during the storage and transport of the TRUPACT-II containers (up to 60 days). One promising option is the use of hydrogen getters. These materials scavenge hydrogen from the gas phase and irreversibly bind it in the solid phase. One proven getter is a material called 1,4-bis (phenylethynyl) benzene, or DEB, characterized by the presence of carbon-carbon triple bonds. Carbon may, in the presence of suitable precious metal catalysts such as palladium, irreversibly react with and bind hydrogen. In the presence of oxygen, the precious metal may also eliminate hydrogen by catalyzing the formation of water. This reaction is called catalytic recombination. DEB has the needed binding rate and capacity for hydrogen that potentially could be generated in the TRUPACT II. Phases 1 and 2 of this project showed that uncoated DEB performed satisfactorily in lab scale tests. Based upon these results, Phase 3, the final project phase, included larger scale testing. Test vessels were scaled to replicate the ratio between void space in the inner containment vessel of a TRUPACT-II container and a payload of seven 55-gallon drums. The tests were run with an atmosphere of air for 63.9 days at ambient temperature (15-27°C) and a scaled hydrogen generation rate of 2.60E-07 moles per second (0.35 cc/min). A second type of getter known as VEI, a proprietary polymer hydrogen getter characterized by carbon-carbon double bonds, was also tested in Phase 3. Hydrogen was successfully “gettered” by both getter systems. Hydrogen concentrations remained below 5 vol% (in

  19. Transient getter scheme for the Tokamak Fusion Test Reactor

    SciTech Connect

    Cecchi, J.L.; Cohen, S.A.; Sredniawski, J.J.

    1980-01-01

    The ability of the Tokamak Fusion Test Reactor (TFTR) to attain the largest fusion power gain depends critically on minimizing plasma contamination and controlling the densities of the reacting deuterium and tritium. Experiments on a number of tokamaks have demonstrated that gettering over an appreciable surface area (greater than or equal to 10%) of the vacuum vessel greatly facilitates both of these objectives. One particular problem in implementing a surface pumping system in TFTR, however, is a restriction on the maximum allowable tritium content of the getter. This restriction could require regeneration of the absorbed tritium after as few as 50 machine pulses. We have developed a scheme utilizing SAES Zr/Al getter modules which obviates the need for such frequent interruptions of machine operation by taking advantage of the pulsed operation of TFTR. With the Zr/Al getter at temperatures between 500/sup 0/C to 600/sup 0/C it is possible to achieve a quasi-steady state in the tritium loading where the quantity of tritium desorbed between pulses is equal to the quantity which is absorbed during a pulse. Since frequent thermal cycling is not required, this scheme also reduces the possibility of Zr/Al getter material fatigue.

  20. Transient getter scheme for the Tokamak Fusion Test Reactor

    SciTech Connect

    Cecchi, J.L.; Cohen, S.A.; Sredniawski, J.J.

    1980-01-01

    The ability of the Tokamak Fusion Test Reactor (TFTR) to attain the largest fusion power gain depends critically on minimizing plasma contamination and controlling the densities of the reacting deuterium and tritium. Experiments on a number of tokamaks have demonstrated that gettering over an appreciable surface area (> or = 10%) of the vacuum vessel greatly facilitates both of these objectives. One particular problem in implementing a surface pumping system in TFTR, however, is a restriction on the maximum allowable tritium content of the getter. This restriction could require regeneration of the absorbed tritium after as few as 50 machine pulses. We have developed a scheme utilizing SAES Zr/Al getter modules which obviates the need for such frequent interruptions of machine operation by taking advantage of the pulsed operation of TFTR. With the Zr/Al getter at temperatures between 500/sup 0/--600/sup 0/C it is possible to achieve a quasisteady state in the tritium loading where the quantity of tritium desorbed between pulses is equal to the quantity which is absorbed during a pulse. Since frequent thermal cycling is not required, this scheme also reduces the possibility of Zr/Al getter material fatigue.

  1. Technetium and Iodine Getters to Improve Cast Stone Performance

    SciTech Connect

    Qafoku, Nikolla; Neeway, James J.; Lawter, Amanda R.; Levitskaia, Tatiana G.; Serne, R. Jeffrey; Westsik, Joseph H.; Snyder, Michelle MV

    2015-02-19

    To determine the effectiveness of the various getter materials prior to their solidification in Cast Stone, a series of batch sorption experiments was performed at Pacific Northwest National Laboratory. To quantify the effectiveness of the removal of Tc(VII) and I(I) from solution by getters, the distribution coefficient, Kd (mL/g), was calculated. Testing involved placing getter material in contact with spiked waste solutions at a 1:100 solid-to-solution ratio for periods up to 45 days with periodic solution sampling. One Tc getter was also tested at a 1:10 solid-to-solution ratio. Two different solution media, 18.2 MΩ deionized water (DI H2O) and a 7.8 M Na LAW simulant, were used in the batch sorption tests. Each test was conducted at room temperature in an anoxic chamber containing N2 with a small amount of H2 (0.7%) to maintain anoxic conditions. Each getter-solution combination was run in duplicate. Three Tc- and I-doping concentrations were used separately in aliquots of both the 18.2 MΩ DI H2O and a 7.8 M Na LAW waste simulant. The 1× concentration was developed based on Hanford Tank Waste Operations Simulator (HTWOS) model runs to support the River Protection Project System Plan Revision 6. The other two concentrations were 5× and 10× of the HTWOS values. The Tc and I tests were run separately (i.e., the solutions did not contain both solutes). Sampling of the solid-solution mixtures occurred nominally after 0.2, 1, 3, 6, 9, 12, 15 days and ~35 to 45 days. Seven getter materials were tested for Tc and five materials were tested for I. The seven Tc getters were blast furnace slag 1 (BFS1) (northwest source), BFS2 (southeast source), Sn(II)-treated apatite, Sn(II) chloride, nano tin phosphate, KMS (a potassium-metal-sulfide), and tin hydroxapatite. The five iodine getters were layered bismuth hydroxide (LBH), argentite mineral, synthetic argentite, silver-treated carbon, and silver-treated zeolite. The Tc Kd values

  2. Technetium and Iodine Getters to Improve Cast Stone Performance

    SciTech Connect

    Qafoku, Nikolla; Neeway, James J.; Lawter, Amanda R.; Levitskaia, Tatiana G.; Serne, R. Jeffrey; Westsik, Joseph H.; Snyder, Michelle MV

    2014-07-01

    To determine the effectiveness of the various getter materials prior to their solidification in Cast Stone, a series of batch sorption experiments was performed at Pacific Northwest National Laboratory. To quantify the effectiveness of the removal of Tc(VII) and I(I) from solution by getters, the distribution coefficient, Kd (mL/g), was calculated. Testing involved placing getter material in contact with spiked waste solutions at a 1:100 solid-to-solution ratio for periods up to 45 days with periodic solution sampling. One Tc getter was also tested at a 1:10 solid-to-solution ratio. Two different solution media, 18.2 MΩ deionized water (DI H2O) and a 7.8 M Na LAW simulant, were used in the batch sorption tests. Each test was conducted at room temperature in an anoxic chamber containing N2 with a small amount of H2 (0.7%) to maintain anoxic conditions. Each getter-solution combination was run in duplicate. Three Tc- and I-doping concentrations were used separately in aliquots of both the 18.2 MΩ DI H2O and a 7.8 M Na LAW waste simulant. The 1× concentration was developed based on Hanford Tank Waste Operations Simulator (HTWOS) model runs to support the River Protection Project System Plan Revision 6. The other two concentrations were 5× and 10× of the HTWOS values. The Tc and I tests were run separately (i.e., the solutions did not contain both solutes). Sampling of the solid-solution mixtures occurred nominally after 0.2, 1, 3, 6, 9, 12, 15 days and ~35 to 45 days. Seven getter materials were tested for Tc and five materials were tested for I. The seven Tc getters were blast furnace slag 1 (BFS1) (northwest source), BFS2 (southeast source), Sn(II)-treated apatite, Sn(II) chloride, nano tin phosphate, KMS (a potassium-metal-sulfide), and tin hydroxapatite. The five iodine getters were layered bismuth hydroxide (LBH), argentite mineral, synthetic argentite, silver-treated carbon, and silver-treated zeolite. The Tc Kd values measured from experiments conducted

  3. A comparison of gettering in single- and multicrystalline silicon for solar cells

    SciTech Connect

    Sopori, B.L.; Jastrzebski, L.; Tan, T.

    1996-05-01

    The differences in the impurity gettering between single and multicrystalline silicon are discussed. These differences arise from impurity-defect interactions that occur during thermal processing of multicrystalline material. A gettering model is proposed to explain the observed behaviour of gettering in multicrystalline cells.

  4. An issue paper on the use of hydrogen getters in transportation packaging

    SciTech Connect

    NIGREY,PAUL J.

    2000-02-01

    The accumulation of hydrogen is usually an undesirable occurrence because buildup in sealed systems pose explosion hazards under certain conditions. Hydrogen scavengers, or getters, can avert these problems by removing hydrogen from such environments. This paper provides a review of a number of reversible and irreversible getters that potentially could be used to reduce the buildup of hydrogen gas in containers for the transport of radioactive materials. In addition to describing getters that have already been used for such purposes, novel getters that might find application in future transport packages are also discussed. This paper also discusses getter material poisoning, the use of getters in packaging, the effects of radiation on getters, the compatibility of getters with packaging, design considerations, regulatory precedents, and makes general recommendations for the materials that have the greatest applicability in transport packaging. At this time, the Pacific Northwest National Laboratory composite getter, DEB [1,4-(phenylethylene)benzene] or similar polymer-based getters, and a manganese dioxide-based getter appear to be attractive candidates that should be further evaluated. These getters potentially can help prevent pressurization from radiolytic reactions in transportation packaging.

  5. Experimental Study of Internal Gettering Efficiency of Iron in Silicon

    NASA Astrophysics Data System (ADS)

    Haarahiltunen, A.; Yli-Koski, M.; Väinölä, H.; Palokangas, M.; Saarnilehto, E.; Sinkkonen, J.

    2004-01-01

    We have studied internal gettering efficiency of iron in silicon by Deep Level Transient Spectroscopy (DLTS) and standard lifetime methods (SPV, µPCD). Conventional high low high anneals were performed to produce a series of wafers with varying denuded zone (DZ) width and oxygen precipitation density. The wafers were intentionally iron contaminated to a level of about 3 5*1013cm 3. After contamination the wafers were annealed at 900°C and then slowly cooled to 850, 800, 750, 700 or 600°C. After cooling the remaining interstitial iron concentration was measured by SPV, µ-PCD and DLTS. The experimental results are compared with simulations. Our results indicate that with this contamination level, the gettering is effective only at temperatures below 750°C when iron is supersaturated over a factor of twenty. For temperatures above 750°C the gettering is limited by iron precipitation in the bulk.

  6. Assuring ultra-clean environments in microsystem packages : irreversible and reversible getters.

    SciTech Connect

    Zifer, Thomas; Whinnery, LeRoy L., Jr.; Hollenshead, Jeromy Todd; Buffleben, George M.; McElhanon, James Ross; Nilson, Robert H.

    2003-11-01

    A new generation of irreversible, chemically reacting getters specifically targeted toward assuring the integrity of the local environment within microsystem packages were developed and evaluated. These reactive getters incorporate volatile species into a polymer through covalent bonds, thus producing a non-volatile product. These reactive getters will be combined with getters that rely on absorption media (e.g. zeolites and high surface area carbon fibers) to scavenge non-reactive species, like solvents. Our getter systems will rely on device packaging to limit exchange between the microsystem and the global environment. Thus, the internal getters need only provide local environmental control within the microsystem package. A series of experiments were conducted to determine uptake rates and capacities absorption and reactive-based getters. Diffusion rates through the binder used to hold the getter particles together were also investigated. Getters were evaluated in environments with a saturated headspace and with a limited amount of the volatile species of interest. One- and two-dimensional numerical models and analysis techniques have been developed and used to predict the transport of contaminant species within a representative microsystem package consisting of an open gas-filled volume adjacent to a polymer layer containing embedded particles of getter. The two-dimensional model features explicit representation of the individual getter particles while the one-dimensional treatment assumes a homogeneous distribution of getter material within the getterlpolymer layer. Example calculations illustrate the dependence of getter performance on reaction rates, polymer diffusivity, and getter particle volume fraction. In addition, the model is used to deduce surface reaction rates, solid phase diffusivities, and maximum-loading densities by least-squares fitting of model predictions to measured histories of gas-phase contaminant concentration and getter weight gain.

  7. Timing of Getter Material Addition in Cementitious Wasteforms

    NASA Astrophysics Data System (ADS)

    Lawter, A.; Qafoku, N. P.; Asmussen, M.; Neeway, J.; Smith, G. L.

    2015-12-01

    A cementitious waste form, Cast Stone, is being evaluated as a possible supplemental immobilization technology for the Hanford sites's low activity waste (LAW), which contains radioactive 99Tc and 129I, as part of the tank waste cleanup mission. Cast Stone is made of a dry blend 47% blast furnace slag, 45% fly ash, and 8% ordinary Portland cement, mixed with a low-activity waste (LAW). To improve the retention of Tc and/or I in Cast Stone, materials with a high affinity for Tc and/or I, termed "getters," can be added to provide a stable domain for the radionuclides of concern. Previous testing conducted with a variety of getters has identified Tin(II)-Apatite and Silver Exchanged Zeolite as promising candidates for Tc and I, respectively. Investigation into the sequence in which getters are added to Cast Stone was performed following two methods: 1) adding getters to the Cast Stone dry blend, and then mixing with liquid waste, and 2) adding getters to the liquid waste first, followed by addition of the Cast Stone dry blend. Cast Stone monolith samples were prepared with each method and leach tests, following EPA method 1315, were conducted in either distilled water or simulated vadose zone porewater for a period of up to 63 days. The leachate was analyzed for Tc, I, Na, NO3-, NO2- and Cr with ICP-MS, ICP-OES and ion chromatography and the results indicated that the Cast Stone with getter addition in the dry blend mix (method 1) has lower rates of Tc and I leaching. The mechanisms of radionuclide release from the Cast Stone were also investigated with a variety of solid phase characterization techniques of the monoliths before and after leaching, such as XRD, SEM/EDS, TEM/SAED and other spectroscopic techniques.

  8. Impurity gettering in silicon using cavities formed by helium implantation and annealing

    DOEpatents

    Myers, S.M. Jr.; Bishop, D.M.; Follstaedt, D.M.

    1998-11-24

    Impurity gettering in silicon wafers is achieved by a new process consisting of helium ion implantation followed by annealing. This treatment creates cavities whose internal surfaces are highly chemically reactive due to the presence of numerous silicon dangling bonds. For two representative transition-metal impurities, copper and nickel, the binding energies at cavities were demonstrated to be larger than the binding energies in precipitates of metal silicide, which constitutes the basis of most current impurity gettering. As a result the residual concentration of such impurities after cavity gettering is smaller by several orders of magnitude than after precipitation gettering. Additionally, cavity gettering is effective regardless of the starting impurity concentration in the wafer, whereas precipitation gettering ceases when the impurity concentration reaches a characteristic solubility determined by the equilibrium phase diagram of the silicon-metal system. The strong cavity gettering was shown to induce dissolution of metal-silicide particles from the opposite side of a wafer. 4 figs.

  9. Impurity gettering in silicon using cavities formed by helium implantation and annealing

    DOEpatents

    Myers, Jr., Samuel M.; Bishop, Dawn M.; Follstaedt, David M.

    1998-01-01

    Impurity gettering in silicon wafers is achieved by a new process consisting of helium ion implantation followed by annealing. This treatment creates cavities whose internal surfaces are highly chemically reactive due to the presence of numerous silicon dangling bonds. For two representative transition-metal impurities, copper and nickel, the binding energies at cavities were demonstrated to be larger than the binding energies in precipitates of metal silicide, which constitutes the basis of most current impurity gettering. As a result the residual concentration of such impurities after cavity gettering is smaller by several orders of magnitude than after precipitation gettering. Additionally, cavity gettering is effective regardless of the starting impurity concentration in the wafer, whereas precipitation gettering ceases when the impurity concentration reaches a characteristic solubility determined by the equilibrium phase diagram of the silicon-metal system. The strong cavity gettering was shown to induce dissolution of metal-silicide particles from the opposite side of a wafer.

  10. Gettering of hydrogen and methane from a helium gas mixture

    SciTech Connect

    Cárdenas, Rosa Elia; Stewart, Kenneth D.; Cowgill, Donald F.

    2014-11-01

    In this study, the authors developed an approach for accurately quantifying the helium content in a gas mixture also containing hydrogen and methane using commercially available getters. The authors performed a systematic study to examine how both H{sub 2} and CH{sub 4} can be removed simultaneously from the mixture using two SAES St 172{sup ®} getters operating at different temperatures. The remaining He within the gas mixture can then be measured directly using a capacitance manometer. The optimum combination involved operating one getter at 650 °C to decompose the methane, and the second at 110 °C to remove the hydrogen. This approach eliminated the need to reactivate the getters between measurements, thereby enabling multiple measurements to be made within a short time interval, with accuracy better than 1%. The authors anticipate that such an approach will be particularly useful for quantifying the He-3 in mixtures that include tritium, tritiated methane, and helium-3. The presence of tritiated methane, generated by tritium activity, often complicates such measurements.

  11. Exceptional gettering response of epitaxially grown kerfless silicon

    DOE PAGES

    Powell, D. M.; Markevich, V. P.; Hofstetter, J.; ...

    2016-02-08

    The bulk minority-carrier lifetime in p- and n-type kerfless epitaxial (epi) crystalline silicon wafers is shown to increase >500 during phosphorus gettering. We employ kinetic defect simulations and microstructural characterization techniques to elucidate the root cause of this exceptional gettering response. Simulations and deep-level transient spectroscopy (DLTS) indicate that a high concentra- tion of point defects (likely Pt) is “locked in” during fast (60 C/min) cooling during epi wafer growth. The fine dispersion of moderately fast-diffusing recombination-active point defects limits as-grown lifetime but can also be removed during gettering, confirmed by DLTS measurements. Synchrotron-based X-ray fluorescence microscopy indicates metal agglomeratesmore » at structural defects, yet the structural defect density is sufficiently low to enable high lifetimes. Consequently, after phosphorus diffusion gettering, epi silicon exhibits a higher lifetime than materials with similar bulk impurity contents but higher densities of structural defects, including multicrystalline ingot and ribbon silicon materials. As a result, device simulations suggest a solar-cell efficiency potential of this material >23%.« less

  12. Gettering of Hydrogen and Methane from a Helium Gas Mixture

    DOE PAGES

    Cardenas, Rosa E.; Stewart, Kenneth D.; Cowgill, Donald F.

    2014-10-21

    In our study, the authors developed an approach for accurately quantifying the helium content in a gas mixture also containing hydrogen and methane using commercially available getters. The authors performed a systematic study to examine how both H2 and CH4 can be removed simultaneously from the mixture using two SAES St 172® getters operating at different temperatures. The remaining He within the gas mixture can then be measured directly using a capacitance manometer. Moreover, the optimum combination involved operating one getter at 650°C to decompose the methane, and the second at 110°C to remove the hydrogen. Finally, this approach eliminatedmore » the need to reactivate the getters between measurements, thereby enabling multiple measurements to be made within a short time interval, with accuracy better than 1%. The authors anticipate that such an approach will be particularly useful for quantifying the He-3 in mixtures that include tritium, tritiated methane, and helium-3. The presence of tritiated methane, generated by tritium activity, often complicates such measurements.« less

  13. Gettering of Hydrogen and Methane from a Helium Gas Mixture

    SciTech Connect

    Cardenas, Rosa E.; Stewart, Kenneth D.; Cowgill, Donald F.

    2014-10-21

    In our study, the authors developed an approach for accurately quantifying the helium content in a gas mixture also containing hydrogen and methane using commercially available getters. The authors performed a systematic study to examine how both H2 and CH4 can be removed simultaneously from the mixture using two SAES St 172® getters operating at different temperatures. The remaining He within the gas mixture can then be measured directly using a capacitance manometer. Moreover, the optimum combination involved operating one getter at 650°C to decompose the methane, and the second at 110°C to remove the hydrogen. Finally, this approach eliminated the need to reactivate the getters between measurements, thereby enabling multiple measurements to be made within a short time interval, with accuracy better than 1%. The authors anticipate that such an approach will be particularly useful for quantifying the He-3 in mixtures that include tritium, tritiated methane, and helium-3. The presence of tritiated methane, generated by tritium activity, often complicates such measurements.

  14. Exceptional gettering response of epitaxially grown kerfless silicon

    SciTech Connect

    Powell, D. M.; Markevich, V. P.; Hofstetter, J.; Jensen, M. A.; Morishige, A. E.; Castellanos, S.; Lai, B.; Peaker, A. R.; Buonassisi, T.

    2016-02-08

    The bulk minority-carrier lifetime in p- and n-type kerfless epitaxial (epi) crystalline silicon wafers is shown to increase >500 during phosphorus gettering. We employ kinetic defect simulations and microstructural characterization techniques to elucidate the root cause of this exceptional gettering response. Simulations and deep-level transient spectroscopy (DLTS) indicate that a high concentra- tion of point defects (likely Pt) is “locked in” during fast (60 C/min) cooling during epi wafer growth. The fine dispersion of moderately fast-diffusing recombination-active point defects limits as-grown lifetime but can also be removed during gettering, confirmed by DLTS measurements. Synchrotron-based X-ray fluorescence microscopy indicates metal agglomerates at structural defects, yet the structural defect density is sufficiently low to enable high lifetimes. Consequently, after phosphorus diffusion gettering, epi silicon exhibits a higher lifetime than materials with similar bulk impurity contents but higher densities of structural defects, including multicrystalline ingot and ribbon silicon materials. As a result, device simulations suggest a solar-cell efficiency potential of this material >23%.

  15. Titanium-nitrogen reaction investigated for application to gettering systems

    NASA Technical Reports Server (NTRS)

    Arntzen, J. D.; Coleman, L. F.; Kyle, M. L.; Pierce, R. D.

    1968-01-01

    Titanium is one of several gettering materials available for removing nitrogen from inert gases. The reaction rate of titanium-metal sponge and nitrogen in argon-nitrogen mixtures was studied at 900 degrees C. The rate was found to depend upon the partial pressure of nitrogen in the gas phase. Mathematical relationships simulate titanium systems.

  16. Exceptional gettering response of epitaxially grown kerfless silicon

    NASA Astrophysics Data System (ADS)

    Powell, D. M.; Markevich, V. P.; Hofstetter, J.; Jensen, M. A.; Morishige, A. E.; Castellanos, S.; Lai, B.; Peaker, A. R.; Buonassisi, T.

    2016-02-01

    The bulk minority-carrier lifetime in p- and n-type kerfless epitaxial (epi) crystalline silicon wafers is shown to increase >500× during phosphorus gettering. We employ kinetic defect simulations and microstructural characterization techniques to elucidate the root cause of this exceptional gettering response. Simulations and deep-level transient spectroscopy (DLTS) indicate that a high concentration of point defects (likely Pt) is "locked in" during fast (60 °C/min) cooling during epi wafer growth. The fine dispersion of moderately fast-diffusing recombination-active point defects limits as-grown lifetime but can also be removed during gettering, confirmed by DLTS measurements. Synchrotron-based X-ray fluorescence microscopy indicates metal agglomerates at structural defects, yet the structural defect density is sufficiently low to enable high lifetimes. Consequently, after phosphorus diffusion gettering, epi silicon exhibits a higher lifetime than materials with similar bulk impurity contents but higher densities of structural defects, including multicrystalline ingot and ribbon silicon materials. Device simulations suggest a solar-cell efficiency potential of this material >23%.

  17. Nuclear breeder reactor fuel element with silicon carbide getter

    DOEpatents

    Christiansen, David W.; Karnesky, Richard A.

    1987-01-01

    An improved cesium getter 28 is provided in a breeder reactor fuel element or pin in the form of an extended surface area, low density element formed in one embodiment as a helically wound foil 30 located with silicon carbide, and located at the upper end of the fertile material upper blanket 20.

  18. Hydrogen gettering the overpressure gas from highly radioactive liquids

    SciTech Connect

    Riley, D.L.; McCoy, J.C.; Schicker, J.R.

    1996-04-01

    Remediation of current inventories of high-activity radioactive liquid waste (HALW) requires transportation of Type-B quantities of radioactive material, possibly up to several hundred liters. However, the only currently certified packaging is limited to quantities of 50 ml (0.01 gal) quantities of Type-B radioactive liquid. Efforts are under way to recertify the existing packaging to allow the shipment of up to 4 L (1.1 gal) of Type-B quantities of HALW, but significantly larger packaging could be needed in the future. Scoping studies and preliminary designs have identified the feasibility of retrofitting an insert into existing casks, allowing the transport of up to 380 L (100 gal) of HALW. However, the insert design and ultimate certification strategy depend heavily on the gas-generating attributes of the HALW. A non-vented containment vessel filled with HALW, in the absence of any gas-mitigation technologies, poses a deflagration threat and, therefore, gas generation, specifically hydrogen generation, must be reliably controlled during all phases of transportation. Two techniques are available to mitigate hydrogen accumulation: recombiners and getters. Getters have an advantage over recombiners in that oxides are not required to react with the hydrogen. A test plan was developed to evaluate three forms of getter material in the presence of both simulated HALW and the gases that are produced by the HALW. These tests demonstrated that getters can react with hydrogen in the presence of simulated waste and in the presence of several other gases generated by the HALW, such as nitrogen, ammonia, nitrous oxide, and carbon monoxide. Although the use of such a gettering system has been shown to be technically feasible, only a preliminary design for its use has been completed. No further development is planned until the requirement for bulk transport of Type-B quantities of HALW is more thoroughly defined.

  19. Results of applying a non-evaporative mitigation technique to laser-initiated surface damage on fused-silica

    SciTech Connect

    Adams, J J; Bolourchi, M; Bude, J D; Guss, G M; Matthews, M J; Nostrand, M C

    2010-10-26

    We present results from a study to determine an acceptable CO{sub 2} laser-based non-evaporative mitigation protocol for use on surface damage sites in fused-silica optics. A promising protocol is identified and evaluated on a set of surface damage sites created under ICF-type laser conditions. Mitigation protocol acceptability criteria for damage re-initiation and growth, downstream intensification, and residual stress are discussed. In previous work, we found that a power ramp at the end of the protocol effectively minimizes the residual stress (<25 MPa) left in the substrate. However, the biggest difficulty in determining an acceptable protocol was balancing between low re-initiation and problematic downstream intensification. Typical growing surface damage sites mitigated with a candidate CO{sub 2} laser-based mitigation protocol all survived 351 nm, 5 ns damage testing to fluences >12.5 J/cm{sup 2}. The downstream intensification arising from the mitigated sites is evaluated, and all but one of the sites has 100% passing downstream damage expectation values. We demonstrate, for the first time, a successful non-evaporative 10.6 {micro}m CO{sub 2} laser mitigation protocol applicable to fused-silica optics used on fusion-class lasers like the National Ignition Facility (NIF).

  20. Backside damage-gettering in cast polycrystalline silicon

    NASA Technical Reports Server (NTRS)

    Culik, J.; Roncin, S.; Alexander, P.

    1984-01-01

    The technique of backside-damage gettering improves the performance of short minority-carrier diffusion length, large-grain (grain diameter greater than 1 to 2 mm), cast polycrystalline silicon. On average, increases of nearly 20 percent in short-circuit current, 10 mV in open-circuit voltage, and 15 percent in peak-power were obtained by heat-treating 300 micron thick polycrystalline wafers at 1000 C in flowing nitrogen for 5 hours. Additional measurements of the bulk and space-charge recombination current components indicate that this improvement results from a significant increase in the minority-carrier diffusion length due to gettering of impurities from the bulk.

  1. Method of gettering hydrogen under conditions of low pressure

    DOEpatents

    Mendelsohn, Marshall H.; Gruen, Dieter M.

    1983-01-01

    A ternary intermetallic compound having the formula Zr(V.sub.1-x Cr.sub.x).sub.2 where x is in the range of 0.01 to 0.90 is capable of reversibly sorbing hydrogen at temperatures ranging from room temperature to 200.degree. C., at pressures down to 10.sup.-6 Torr. The compound is suitable for use as a hydrogen getter in low pressure, high temperature applications such as magnetic confinement fusion devices.

  2. Explosive composition with group VIII metal nitroso halide getter

    DOEpatents

    Walker, Franklin E.; Wasley, Richard J.

    1982-01-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1,500 and 10,000 meters per second and a minor amount of a getter additive comprising a non-explosive compound or mixture of non-explosive compounds capable of chemically reacting with free radicals or ions under shock initiation conditions of 2,000 calories/cm.sup.2 or less of energy fluence.

  3. Explosive composition with group VIII metal nitroso halide getter

    DOEpatents

    Walker, F.E.; Wasley, R.J.

    1982-06-22

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1,500 and 10,000 meters per second and a minor amount of a getter additive comprising a non-explosive compound or mixture of non-explosive compounds capable of chemically reacting with free radicals or ions under shock initiation conditions of 2,000 calories/cm[sup 2] or less of energy fluence.

  4. Getter Incorporation into Cast Stone and Solid State Characterizations

    SciTech Connect

    Asmussen, Robert M.; Lawter, Amanda R.; Stephenson, John R.; Bowden, Mark E.; Washton, Nancy M.; Neeway, James J.; Du, Yingge; Pearce, Carolyn I.; Clayton, Ray E.; Saslow, Sarah A.; Buck, Edgar C.; Cordova, Elsa; Qafoku, Nikolla

    2016-09-28

    Washington River Protection Solutions (WRPS) is collecting relevant available data on waste forms for use as a supplemental immobilization technology, to provide the additional capacity needed to treat low-activity waste (LAW) in Hanford Site tanks and complete the tank waste cleanup mission in a timely and cost-effective manner. One candidate supplemental waste form, fabricated using a low-temperature process, is a cementitious grout called Cast Stone. Cast Stone has been under investigation for this application at Pacific Northwest National Laboratory (PNNL) since initial screening tests in FY13. This report is the culmination of work to lower the diffusivities of Tc and I from Cast Stone using getters. Getters are compounds added to a system designed to selectively sequester a species of interest to provide increased stability to the species. The work contained within this report is related to waste form development and testing and does not directly support the 2017 integrated disposal facility (IDF) performance assessment. However, this work contains valuable information which may be used in performance assessment maintenance past FY17, and in future waste form development. This report on performance characterization of Tc and I getters in Cast Stone fabricated with simulated LAW covers several areas of interest and major findings to WRPS:

  5. Rate limiting mechanism of transition metal gettering in multicrystalline silicon

    SciTech Connect

    McHugo, S.A.; Thompson, A.C.; Imaizumi, M.; Hieslmair, H.; Weberr, E.R.

    1997-07-01

    The authors have performed studies on multicrystalline silicon used for solar cells in the as-grown state and after a series of processing and gettering steps. The principal goal of this work is to determine the rate limiting step for metal impurity gettering from multicrystalline silicon with an emphasis on the release of impurities from structural defects. Synchrotron-based x-ray fluorescence mapping was used to monitor the release process. Copper and nickel impurities were found to reside primarily at dislocations in the as-grown state of the material. Short annealing treatments rapidly dissolved the impurity agglomerates. Based on these results and modeling of the dissolution process, copper and nickel is in the form of small agglomerates (< 10 nm) clustered together over micron-scale regions in the as-grown material. Aluminum gettering further disintegrated the agglomerates to below the sensitivity of the system, 2--5 nm in radii. No significant barrier to release of copper or nickel from dislocations was observed.

  6. Nuclear breeder reactor fuel element with axial tandem stacking and getter

    DOEpatents

    Gibby, Ronald L.; Lawrence, Leo A.; Woodley, Robert E.; Wilson, Charles N.; Weber, Edward T.; Johnson, Carl E.

    1981-01-01

    A breeder reactor fuel element having a tandem arrangement of fissile and fertile fuel with a getter for fission product cesium disposed between the fissile and fertile sections. The getter is effective at reactor operating temperatures to isolate the cesium generated by the fissile material from reacting with the fertile fuel section.

  7. Material problems arising from impurity gettering of lithium by zirconium or titanium

    NASA Astrophysics Data System (ADS)

    Ulrich Borgstedt, Hans

    Hot trapping for purification of lithium is necessary to improve the compatibility of vanadium alloys with the blanket fluid. In hot traps operated at 973 K using titanium or zirconium as getter materials mass transfer between the structural materials, 18Cr-9Ni stainless steels, and the getter materials occurs. Mainly nickel and manganese migrate from the stainless steel housing to the getter foils. The leaching of nickel and manganese causes accelerated corrosion of the structural material. The deposition of nickel on the getter surfaces leads to the formation of crystalline surface layers or diffusion of this element into the foils forming alloys with titanium or zirconium. This second phenomenon may influence the efficiency of the gettering reactions.

  8. Nuclear reactor fuel element with vanadium getter on cladding

    DOEpatents

    Johnson, Carl E.; Carroll, Kenneth G.

    1977-01-01

    A nuclear reactor fuel element is described which has an outer cladding, a central core of fissionable or mixed fissionable and fertile fuel material and a layer of vanadium as an oxygen getter on the inner surface of the cladding. The vanadium reacts with oxygen released by the fissionable material during irradiation of the core to prevent the oxygen from reacting with and corroding the cladding. Also described is a method for coating the inner surface of small diameter tubes of cladding with a layer of vanadium.

  9. Engineering Report on the Fission Gas Getter Concept

    SciTech Connect

    Ecker, Lynne; Ghose, Sanjit; Gill, Simerjeet; Thallapally, Praveen K.; Strachan, Denis M.

    2012-11-01

    In 2010, the Department of Energy (DOE) requested that a Brookhaven National Laboratory (BNL)-led team research the possibility of using a getter material to reduce the pressure in the plenum region of a light water reactor fuel rod. During the first two years of the project, several candidate materials were identified and tested using a variety of experimental techniques, most with xenon as a simulant for fission products. Earlier promising results for candidate getter materials were found to be incorrect, caused by poor experimental techniques. In May 2012, it had become clear that none of the initial materials had demonstrated the ability to adsorb xenon in the quantities and under the conditions needed. Moreover, the proposed corrective action plan could not meet the schedule needed by the project manager. BNL initiated an internal project review which examined three questions: 1. Which materials, based on accepted materials models, might be capable of absorbing xenon? 2. Which experimental techniques are capable of not only detecting if xenon has been absorbed but also determine by what mechanism and the resulting molecular structure? 3. Are the results from the previous techniques useable now and in the future? As part of the second question, the project review team evaluated the previous experimental technique to determine why incorrect results were reported in early 2012. This engineering report is a summary of the current status of the project review, description of newly recommended experiments and results from feasibility studies at the National Synchrotron Light Source (NSLS).

  10. Contamination Effects of Getter Ion and Titanium Sublimation Pumped Systems on Optical Surfaces

    NASA Technical Reports Server (NTRS)

    Visentine, James T.; Richmond, Robert G.

    1973-01-01

    Previous studies have indicated that ultraclean vacuum can be produced when titanium sublimation pumps are used in conjunction with getter-ion pumps. Experiments are described in which the degrees of cleanliness of a typical getter-ion, titanium sublimation-pumped system were monitored by measuring the effects of surface contamination on the reflectance of evaporated vacuum ultraviolet mirrors. Results are presented which indicate that severe reflectance losses occurred when startup of a getter-ion pump was initiated at too high a chamber pressure. Significant reflectance losses also occurred as a result of titanium sublimation-pump operation. These data are reviewed and recommendations for improved system performance are presented.

  11. Self assembled molecular monolayers on high surface area materials as molecular getters

    DOEpatents

    King, D.E.; Herdt, G.C.; Czanderna, A.W.

    1997-01-07

    The present invention relates to a gettering material that may be used as a filtration medium to remove pollutants from the environment. The gettering material comprises a high surface area material having a metal surface that chemically bonds n-alkanethiols in an organized manner thereby forming a molecular monolayer over the metal surface. The n-alkanethiols have a free functional group that interacts with the environment thereby binding specific pollutants that may be present. The gettering material may be exposed to streams of air in heating, ventilation, and air conditioning systems or streams of water to remove specific pollutants from either medium. 9 figs.

  12. Self assembled molecular monolayers on high surface area materials as molecular getters

    DOEpatents

    King, David E.; Herdt, Gregory C.; Czanderna, Alvin W.

    1997-01-01

    The present invention relates to a gettering material that may be used as a filtration medium to remove pollutants from the environment. The gettering material comprises a high surface area material having a metal surface that chemically bonds n-alkanethiols in an organized manner thereby forming a molecular monolayer over the metal surface. The n-alkanethiols have a free functional group that interacts with the environment thereby binding specific pollutants that may be present. The gettering material may be exposed to streams of air in heating, ventilation, and air conditioning systems or streams of water to remove specific pollutants from either medium.

  13. Titanium-Based Getter Solution for Wafer-Level MEMS Vacuum Packaging

    NASA Astrophysics Data System (ADS)

    Chidambaram, Vivek; Ling, Xie; Bangtao, Chen

    2013-03-01

    Ultrahigh-vacuum conditions can be achieved by employing porous absorbent materials such as Ti, Zr, Ta, and Yt. Commercial getters are primarily Zr-based, since Zr possesses the best adsorption characteristics. Titanium is not considered as a candidate, since adsorption of gases by Ti is significantly reduced due to oxidation and other contamination. In the present work, it is demonstrated that the adsorption property of Ti can be substantially enhanced and benchmarked against other Zr-based commercial getters by employing a sacrificial layer such as Ni over Ti, and also by using other surface engineering techniques. It has been confirmed that, in addition to the activation temperature, the vacuum level during getter activation also plays a pivotal role in influencing the adsorption characteristics of Ti. It has been determined that the getter life could be significantly improved by the reversible adsorption characteristic of H2 gas, facilitating regeneration cycles.

  14. Studies of Hydrogen Getter Material Self-decomposition and Reaction Capacity

    SciTech Connect

    Saab, A P; Dinh, L N

    2007-03-19

    Diacetylene based hydrogen getters are examined in order to gauge their self decomposition products, as well as to determine possible origins for observed losses in origins getter capacity. Simple long term (several months) thermal aging tests were conducted, with periodic solid solid-phase micro micro-extraction (SPME) sampling followed by GC/MS analysis. The results suggest that bis(diphenylethynyl) benzene tends to decompose to give phenyl contaminants more readily than diphenylbutadiyne. Transmission electron microscopy (TEM) and electron diffraction studies of the palladium catalyst following varying extents of reaction with hydrogen show that there is no change to the catalyst particles, indicating that any change in capacity originates from other causes. These causes are suggested by Sievert's-type experiments on the reaction of the getter with a low pressure (about 10 Torr) hydrogen atmosphere. The reaction data indicate that the getter capacity depends on the pressure of hydrogen to which the material is exposed, and also its thermal history.

  15. Phosphorus vacancy cluster model for phosphorus diffusion gettering of metals in Si

    SciTech Connect

    Chen, Renyu; Trzynadlowski, Bart; Dunham, Scott T.

    2014-02-07

    In this work, we develop models for the gettering of metals in silicon by high phosphorus concentration. We first performed ab initio calculations to determine favorable configurations of complexes involving phosphorus and transition metals (Fe, Cu, Cr, Ni, Ti, Mo, and W). Our ab initio calculations found that the P{sub 4}V cluster, a vacancy surrounded by 4 nearest-neighbor phosphorus atoms, which is the most favorable inactive P species in heavily doped Si, strongly binds metals such as Cu, Cr, Ni, and Fe. Based on the calculated binding energies, we build continuum models to describe the P deactivation and Fe gettering processes with model parameters calibrated against experimental data. In contrast to previous models assuming metal-P{sub 1}V or metal-P{sub 2}V as the gettered species, the binding of metals to P{sub 4}V satisfactorily explains the experimentally observed strong gettering behavior at high phosphorus concentrations.

  16. 1,4-diphenylbutadiyne as a potential tritium getter

    SciTech Connect

    Miller, H.H.; Bissell, E.E.; Tsugawa, R.T.; Souers, P.C.

    1980-10-01

    Research on the acetylene compound 1,4-diphenylbutadiyne is an effort to develop an air-operative tritium gas scavenger. T/sub 2/ adds to the acetylene bond of the organic in the presence of a metal catalyst. The catalyst also stimulates the oxidation reaction as well. The butadiyne compound has shown good reaction efficiency at 300 ppM T/sub 2/ in static dry air. At this concentration 75% of the scavenged tritium was in the organic. This work has expanded to the investigation of liquid acetylenes, metal acetylene complexes, organometallics and acetylene based alcohols. The best of these compounds has gettered 100% of 10 to 500 ppM T/sub 2/ for both static and dynamic air flow conditions.

  17. Gettering of copper to hydrogen-induced cavities in silicon

    NASA Astrophysics Data System (ADS)

    Wong-Leung, J.; Ascheron, C. E.; Petravic, M.; Elliman, R. G.; Williams, J. S.

    1995-03-01

    Hydrogen implantation and subsequent thermal annealing is found to result in a well-defined band of cavities in Si. This band is an extremely efficient gettering layer for Cu which is also introduced into the near surface of Si by ion implantation. Profiling of implanted Cu indicates that ˜95% of an initial 3×1015 cm-2 Cu implant is redistributed following annealing at a temperature of 780 °C from a near-surface damaged layer to a narrow band of cavities of width ˜1000 Å at a depth of ˜1 μm. Furthermore, the Si between the surface and the cavity band is essentially defect-free and that some cavities contain the bulk Cu3Si phase.

  18. Activation process and absorption/desorption of D2O for Zr-V-Fe getter

    NASA Astrophysics Data System (ADS)

    Ichimura, K.; Inoue, N.; Ashida, K.; Watanabe, K.; Takeuchi, T.

    1984-12-01

    Nonevaporable getters have wide applicability for tritium handling systems. From this view point, the activation process of the Zr-V-Fe getter (St-707) and absorption/desorption of D2O on the getter surface were investigated, by means of XPS-SIMS and mass analyzed thermal desorption spectroscopy. XPS-SIMS measurements revealed that the getter surface exposed to air was covered with adsorbed H2O, CO and small amounts of hydrocarbons and that the getter components are oxidized. Upon heating of the getter above 500 °C, the adsorbed species disappeared from the surface, partly due to desorption and partly due to migration into the bulk. Consequently, metallic Zr and V appeared on the surface, whereas Fe disappeared. The surface composition was evaluated to be 87 at% Zr-13 at% V. After the activation, water (D2O ) was readily absorbed into the getter at 300 °C in the form of deuterium atoms. The absorption rate was proportional to the partial pressure of water, indicating that the rate determining step for the absorption is the dissociation of water molecules on the surface. The absorption rate constant was 0.009 and 0.24 cc/s/cm2 (net surface area) [or 1.5 and 39 cc/s/cm2 (projected area)] at 25 and 300°C, respectively. Only D2 was desorbed from the getter exposed to D2O at 25 and 300 °C. The rate determining step for the desorption is association of deuterium atoms on the surface diffused from the bulk.

  19. The Effects of Temperature and Carbon Tetrachloride on Polymer Based Hydrogen Getters

    SciTech Connect

    George M. Buffleben; Timothy J. Shepod

    2000-12-01

    This report summarizes hydrogen pumping by organic getters in the presence of carbon tetrachloride, and how the reduction of pumping in the presence of this catalyst poison can be minimized through the choice of catalyst. Catalyst A is shown to be preferred in a clean environment, and catalyst B for a poisoned environment. Additional, we examine the effects of temperature on pumping rates, and show that this getter is effective over a large temperature range from -23 to 107 degrees Celsius.

  20. Diffusive Barrier and Getter Under Waste Packages VA Reference Design Feature Evaluations

    SciTech Connect

    MacNeil, K.

    1999-05-24

    This technical document evaluates those aspects of the diffusive barrier and getter features which have the potential for enhancing the performance of the Viability Assessment Reference Design and are also directly related to the key attributes for the repository safety strategy of that design. The effects of advection, hydrodynamic dispersion, and diffusion on the radionuclide migration rates through the diffusive barrier were determined through the application of the one-dimensional, advection/dispersion/diffusion equation. The results showed that because advective flow described by the advection-dispersion equation dominates, the diffusive barrier feature alone would not be effective in retarding migration of radiocuclides. However, if the diffusive barrier were combined with one or more features that reduced the potential for advection, then transport of radionuclides would be dominated by diffusion and their migration from the EBS would be impeded. Apatite was chosen as the getter material used for this report. Two getter configurations were developed, Case 1 and Case 2. As in the evaluation of the diffusive barrier, the effects of advection, hydrodynamic dispersion, and diffusion on the migration of radionuclides through the getter are evaluated. However, in addition to these mechanisms, the one-dimensional advection/dispersion/diffusion model is modified to include the effect of sorption on radionuclide migration rates through the sorptive medium (getter). As a result of sorption, the longitudinal dispersion coefficient, and the average linear velocity are effectively reduced by the retardation factor. The retardation factor is a function of the getter material's dry bulk density, sorption coefficient and moisture content. The results of the evaluation showed that a significant delay in breakthrough through the getter can be achieved if the thickness of the getter barrier is increased.

  1. Segregation gettering by implantation-formed cavities and B-Si precipitates in silicon

    SciTech Connect

    Myers, S.M.; Petersen, G.A.; Follstaedt, D.M.

    1998-01-01

    The authors show that Fe, Co, Cu, and Au in Si undergo strong segregation gettering to cavities and B-Si precipitates formed by He or B ion implantation and annealing. The respective mechanisms are argued to be chemisorption on the cavity walls and occupation of solution sites within the disordered, B-rich, B-Si phase. The strengths of the reactions are evaluated, enabling prediction of gettering performance.

  2. Contact formation and gettering of precipitated impurities by multiple firing during semiconductor device fabrication

    DOEpatents

    Sopori, Bhushan

    2014-05-27

    Methods for contact formation and gettering of precipitated impurities by multiple firing during semiconductor device fabrication are provided. In one embodiment, a method for fabricating an electrical semiconductor device comprises: a first step that includes gettering of impurities from a semiconductor wafer and forming a backsurface field; and a second step that includes forming a front contact for the semiconductor wafer, wherein the second step is performed after completion of the first step.

  3. Performance testing of aged hydrogen getters against criteria for interim safe storage of plutonium bearing materials.

    SciTech Connect

    Shepodd, Timothy J.; Nissen, April; Buffleben, George M.

    2006-01-01

    Hydrogen getters were tested for use in storage of plutonium-bearing materials in accordance with DOE's Criteria for Interim Safe Storage of Plutonium Bearing Materials. The hydrogen getter HITOP was aged for 3 months at 70 C and tested under both recombination and hydrogenation conditions at 20 and 70 C; partially saturated and irradiated aged getter samples were also tested. The recombination reaction was found to be very fast and well above the required rate of 45 std. cc H2h. The gettering reaction, which is planned as the backup reaction in this deployment, is slower and may not meet the requirements alone. Pressure drop measurements and {sup 1}H NMR analyses support these conclusions. Although the experimental conditions do not exactly replicate the deployment conditions, the results of our conservative experiments are clear: the aged getter shows sufficient reactivity to maintain hydrogen concentrations below the flammability limit, between the minimum and maximum deployment temperatures, for three months. The flammability risk is further reduced by the removal of oxygen through the recombination reaction. Neither radiation exposure nor thermal aging sufficiently degrades the getter to be a concern. Future testing to evaluate performance for longer aging periods is in progress.

  4. Design optimization of metal getter reactors for removing tritium from flowing gas streams

    SciTech Connect

    Nobile, A.; Bieniewski, T.; Frame, K.; Little, R.; Fisher, K.

    1995-10-01

    A reaction engineering approach was used to design a SAES St 198 metal getter reactor for a glovebox detritiation system. The detritiation system will be used to decontaminate and decommission an Li(D, T)-contaminated glovebox previously used in the U.S. nuclear weapons program. The approach involved development of a model that calculates reactor breakthrough curves as a function of various reactor physical parameters. Experiments involving flow of deuterium in nitrogen through a small metal getter reactor validated the model. The model was then used to investigate the effects of temperature, getter pellet size, reactor diameter, and reactor volume on the reactor performance. The resulting design was a 7 cm diam. by 40 cm long cylindrical reactor that operates at 250 {degree}C, and is filled with 5 kg of as-received SAES St 198 getter pellets. The reactor handles a flow rate of 100 L/min. An St 909 getter reactor was used upstream of the St 198 reactor for impurity removal and water decomposition. The glovebox cleanup system design and getter reactor mechanical design are discussed. 14 refs., 6 figs.

  5. Phosphorus diffusion gettering process of multicrystalline silicon using a sacrificial porous silicon layer

    NASA Astrophysics Data System (ADS)

    Lotfi, Derbali; Hatem, Ezzaouia

    2012-07-01

    The aims of this work are to getter undesirable impurities from low-cost multicrystalline silicon (mc-Si) wafers and then enhance their electronic properties. We used an efficient process which consists of applying phosphorus diffusion into a sacrificial porous silicon (PS) layer in which the gettered impurities have been trapped after the heat treatment. As we have expected, after removing the phosphorus-rich PS layer, the electrical properties of the mc-Si wafers were significantly improved. The PS layers, realized on both sides of the mc-Si substrates, were formed by the stain-etching technique. The phosphorus treatment was achieved using a liquid POCl3-based source on both sides of the mc-Si wafers. The realized phosphorus/PS/Si/PS/phosphorus structures were annealed at a temperature ranging between 700°C and 950°C under a controlled O2 atmosphere, which allows phosphorus to diffuse throughout the PS layers and to getter eventual metal impurities towards the phosphorus-doped PS layer. The effect of this gettering procedure was investigated by means of internal quantum efficiency and the dark current-voltage ( I- V) characteristics. The minority carrier lifetime measurements were made using a WTC-120 photoconductance lifetime tester. The serial resistance and the shunt resistance carried out from the dark I- V curves confirm this gettering-related solar cell improvement. It has been shown that the photovoltaic parameters of the gettered silicon solar cells were improved with regard to the ungettered one, which proves the beneficial effect of this gettering process on the conversion efficiency of the multicrystalline silicon solar cells.

  6. Contamination and gettering evaluation by lifetime measurements during single crystal cell processing

    SciTech Connect

    Lagos, R.; Moehlecke, A.; Alonso, J.; Tobias, I.; Luque, A.

    1994-12-31

    In this work, the effects of contamination and gettering through two fabrication processes of monocrystalline solar cells are evaluated using lifetime measurements. The processes characterized were developed to produce n{sup +}pp{sup +} and p{sup +}nn{sup +} solar cells with phosphorus/aluminum and boron/phosphorus. The experiments indicate that in the laboratory environment, the lifetime degradation is influenced by the number of thermal processes. The gettering produced by aluminum in n{sup +}pp{sup +} cell processing and by phosphorus (with heavy doping) in p{sup +}nn{sup +} cell processing enhances the base lifetime. Slight phosphorus diffusion without supersaturation conditions, performed in the n{sup +}pp{sup +} process, does not produce sufficient gettering and has lower effect on the lifetime than boron diffusions that produce some gettering too. Also, the authors discovered that gettering is strongly reduced when local aluminum back surface field regions are formed in the rear face in a failed attempt of reducing the BSF recombination.

  7. Savannah River Site/K Area Complex getter life extension report.

    SciTech Connect

    Shepodd, Timothy J.; Woodsmall, Todd; Nissen, April

    2008-08-01

    The K Area Complex (KAC) at the Savannah River Site (SRS) has been utilizing HiTop hydrogen getter material in 9975 Shipping Containers to prevent the development of flammable environments during storage of moisture-containing plutonium oxides. Previous testing and subsequent reports have been performed and produced by Sandia National Laboratories (SNL) to demonstrate the suitability and longevity of the getter during storage at bounding thermal conditions. To date, results have shown that after 18 months of continuous storage at 70 C, the getter is able to both recombine gaseous hydrogen and oxygen into water when oxygen is available, and irreversibly getter (i.e. scavenge) hydrogen from the vapor space when oxygen is not available, both under a CO{sub 2} environment. [Refs. 1-5] Both of these reactions are catalytically enhanced and thermodynamically favorable. The purpose of this paper is to establish the justification that maintaining the current efforts of biannual testing is no longer necessary due to the robust performance of the getter material, the very unlikely potential that the recombination reaction will fail during storage conditions in KAC, and the insignificant aging effects that have been seen in the testing to date.

  8. Dependence of nickel gettering on crystalline nature in as-grown Czochralski silicon wafer

    NASA Astrophysics Data System (ADS)

    Lee, In-Ji; Paik, Ungyu; Park, Jea-Gun

    2013-02-01

    The efficiency of nickel gettering in vacancy- and interstitial-silicon-dominant crystalline nature was studied using wafers cut along the axial direction of a CZ-grown silicon ingot grown with a variable v/G ratio. Six crystalline areas (V-rich, P-band, PV, PI, B-band, and I-rich) were present within one wafer. Nickel gettering efficiency was estimated before and after a typical NAND-flash-memory heat-treatment. With as-grown CZ silicon wafers, nickel gettering depends on the crystalline nature, i.e., nickel atoms are mainly gathered at oxygen precipitates in bulk at vacancy-dominant crystalline regions and at the surface of pure silicon in the interstitial-silicon-dominant crystal region (PI). Rapid thermal annealing of a CZ silicon wafer at 1175 °C for 10 s in Ar/NH3 mixture ambient completely erased the dependency of nickel gettering on the crystalline nature and demonstrated an excellent getting ability for nickel contamination via the relaxation gettering of oxygen precipitates.

  9. Nitrogen Impurity Gettering in Oxide Dispersion Ductilized Chromium

    SciTech Connect

    Brady, Michael P; Anderson, Ian M; Weaver, Mark; Meyer III, Harry M; Walker, Larry R; Miller, Michael K; Larson, David James; Wright, Ian G; Sikka, Vinod K; Rar, Andrei; Pharr, George Mathews; Keiser, James R; Walls, Claudia Alexandra

    2003-01-01

    Work by Scruggs in the 1960s demonstrated that tensile ductility could be achieved at room temperature in powder metallurgically-produced Cr alloyed with MgO. During consolidation, much of the MgO converted to the MgCr{sub 2}O{sub 4} spinel phase, which was hypothesized to getter nitrogen from the Cr, rendering it ductile. We have duplicated this effect, achieving room temperature tensile elongations of 4% for hot-pressed Cr-6MgO-(0-1)Ti (wt.%) and 10% for hot-pressed and extruded Cr-6MgO-0.75Ti. Direct incorporation of nitrogen into the MgCr{sub 2}O{sub 4} phase was not detected; however, impurities, particularly nitrogen and sulfur, were observed to segregate to and/or precipitate at interfaces between the MgO/MgCr{sub 2}O{sub 4} phases and the Cr matrix. Exploratory studies of other non-spinel forming oxide dispersions (La{sub 2}O{sub 3}, TiO{sub 2} and Y{sub 2}O{sub 3}) showed a similar pattern of impurity segregation/precipitation, suggesting that there is nothing unique about spinel dispersions in Cr with regards to impurities. However, none of these other dispersions resulted in similar levels of tensile elongation.

  10. Cavity formation and impurity gettering in He-implanted Si

    SciTech Connect

    Follstaedt, D.M.; Myers, S.M.; Petersen, G.A.; Medernach, J.W.

    1994-12-31

    Cavity microstructures formed in Si after ion implantation of He and annealing at 700 C or above are examined with cross-section transmission electron microscopy. A threshold concentration of 1.6 at.% He is identified to form cavities that survive such anneals. The cavities coarsen with a constant volume of 15 nm{sup 3}/nm{sup 2} (per wafer surface area), corresponding to {approximately}0.75 lattice sites per implanted He atom. The internal area of the cavities is 3--7 times that of the wafer surface area for fluences of 1 {times} 10{sup 17} He/cm{sup 2}. Transition metal atoms (Cu, Ni, Co, Fe, Au) are shown to be strongly trapped (1.5--2.2 eV) on the cavity walls by chemisorption. Whereas Cu, Au and Ni are bound more strongly to the cavity sites than to their respective precipitated phases, Co and Fe are more strongly bound to their silicides; nonetheless, appreciable trapping of Co and Fe does occur in equilibrium with the silicides. Cavity trapping appears to be an effective gettering mechanism at low impurity levels, as needed to meet future microelectronics device requirements.

  11. Low temperature iron gettering by grown-in defects in p-type Czochralski silicon

    NASA Astrophysics Data System (ADS)

    Zhu, Haiyan; Yu, Xuegong; Zhu, Xiaodong; Wu, Yichao; He, Jian; Vanhellemont, Jan; Yang, Deren

    2016-11-01

    Low temperature iron gettering in as-grown boron doped Czochralski silicon (Cz-Si) at temperatures between 220 and 500 °C is studied using microwave-photoconductive decay based minority carrier lifetime measurements. Scanning infrared microscopy technique is used to study the defect density/size distribution in the samples before and after anneal. It is found that the decrease of interstitial iron (Fei) concentration shows a double exponential dependence on annealing time at all temperatures. This suggests the existence of two sinks for Fei. Meanwhile, the observed bulk defect densities and sizes in contaminated and as-grown samples are nearly the same, implying that the grown-in defects could be the gettering centers in this process. The results are important for understanding and controlling low temperature Fei gettering during processing of Cz-Si based devices.

  12. Carbon monoxide formation in UO2 kerneled HTR fuel particles containing oxygen getters

    NASA Astrophysics Data System (ADS)

    Proksch, E.; Strigl, A.; Nabielek, H.

    1986-01-01

    Mass spectrometric measurements of CO in irradiated UO2 fuel particles containing oxygen getters are summarized. Uranium carbide addition in the 3% to 15% range reduces the CO release by factors between 25 and 80, up to burn-up levels as high as 70% FIMA. Unintentional gettering by SiC in TRISO coated particles with failed inner pyrocarbon layers results in CO reduction factors between 15 and 110. For ZrC, ambiguous results are obtained; ZrC probably results in CO reduction by a factor of 40; Ce2O3 and La2O3 seem less effective than the carbides; for Ce2O3, reduction factors between 3 and 15 are found. However, the results are possibly incorrect due to premature oxidation of the getter already during fabrication. Addition of SiO2 + Al2O3 has no influence on CO release.

  13. Combined gettering and molten salt process for tritium recovery from lithium

    SciTech Connect

    Sze, D.K.; Finn, P.A.; Bartlit, J.; Tanaka, S.; Teria, T.; Yamawaki, M.

    1988-02-01

    A new tritium recovery concept from lithium has been developed as part of the US/Japan collaboration on Reversed-Field Pinch Reactor Design Studies. This concept combines the ..gamma..-gettering process as the front end to recover tritium from the coolant, and a molten salt recovery process to extract tritium for fuel processing. A secondary lithium is used to regenerate the tritium from the gettering bed and, in the process, increases the tritium concentration by a factor of about 20. That way, the required size of the molten salt process becomes very small. A potential problem is the possible poisoning of the gettering bed by the salt dissolved in lithium. 16 refs., 6 figs.

  14. Gettering of transition metals by cavities in silicon formed by helium ion implantation

    SciTech Connect

    Petersen, G.A.; Myers, S.M.; Follstaedt, D.M.

    1996-09-01

    We have recently completed studies which quantitatively characterize the ability of nanometer-size cavities formed by He ion implantation to getter detrimental metal impurities in Si. Cavity microstructures formed in Si by ion implantation of He and subsequent annealing have been found to capture metal impurities by two mechanisms: (1) chemisorption on internal walls at low concentrations and (2) silicide precipitation at concentrations exceeding the solid solubility. Experiments utilizing ion-beam analysis, cross-sectional transmission electron microscopy, and secondary ion mass spectrometry were performed to quantitatively characterize the gettering effects and to determine the free energies associated with the chemisorbed metal atoms as a function of temperature. Mathematical models utilizing these results have been developed to predict gettering behavior.

  15. Analytic study of developing flows in a tube laden with non-evaporating and evaporating drops via a modified linearization of the two-phase momentum equations

    NASA Astrophysics Data System (ADS)

    Khosid, S.; Tambour, Y.

    A novel modification of the classical Langhaar linearization of the mutually coupled momentum equations for developing two-phase flows in circular ducts is presented. This modification enables us to treat: (i) flows developing from spatially periodic initial velocity distributions without the presence of droplets, and (ii) two-phase flows in which monosize, non-evaporating and evaporating droplets suspended in a developing gas flow of an initially uniform velocity distribution exchange momentum with the host-gas flow. New solutions are presented for the downstream evolution in the velocity profiles which develop from spatially periodic initial velocity distributions that eventually reach the fully developed Poiseuille velocity profile. These solutions are validated by employing known numerical procedures, providing strong support for the physical underpinnings of the present modified linearization. New solutions are also presented for the evolution in drop velocities and vapour spatial distributions for evaporating droplets suspended in an initially uniform velocity profile of the host gas. Asymptotic solutions are presented for the flow region which lies very close to the inlet of the tube, where the relative velocity between the droplets and the host gas is high, and thus the velocity fields of the two phases are mutually coupled. These solutions provide new explicit formulae for the droplet velocity field as a function of the initial conditions and droplet diameter (relative to the tube diameter) for non-evaporating drops, and also as a function of evaporation rate for evaporating drops.

  16. Oxygen "getter" effects on microstructure and carrier transport in low temperature combustion-processed a-InXZnO (X = Ga, Sc, Y, La) transistors.

    PubMed

    Hennek, Jonathan W; Smith, Jeremy; Yan, Aiming; Kim, Myung-Gil; Zhao, Wei; Dravid, Vinayak P; Facchetti, Antonio; Marks, Tobin J

    2013-07-24

    In oxide semiconductors, such as those based on indium zinc oxide (IXZO), a strong oxygen binding metal ion ("oxygen getter"), X, functions to control O vacancies and enhance lattice formation, hence tune carrier concentration and transport properties. Here we systematically study, in the IXZO series, the role of X = Ga(3+) versus the progression X = Sc(3+) → Y(3+) → La(3+), having similar chemical characteristics but increasing ionic radii. IXZO films are prepared from solution over broad composition ranges for the first time via low-temperature combustion synthesis. The films are characterized via thermal analysis of the precursor solutions, grazing incidence angle X-ray diffraction (GIAXRD), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM) with high angle annular dark field (HAADF) imaging. Excellent thin-film transistor (TFT) performance is achieved for all X, with optimal compositions after 300 °C processing exhibiting electron mobilities of 5.4, 2.6, 2.4, and 1.8 cm(2) V(-1) s(-1) for Ga(3+), Sc(3+), Y(3+), and La(3+), respectively, and with I(on)/I(off) = 10(7)-10(8). Analysis of the IXZO TFT positive bias stress response shows X = Ga(3+) to be superior with mobilities (μ) retaining >95% of the prestress values and threshold voltage shifts (ΔV(T)) of <1.6 V, versus <85% μ retention and ΔV(T) ≈ 20 V for the other trivalent ions. Detailed microstructural analysis indicates that Ga(3+) most effectively promotes oxide lattice formation. We conclude that the metal oxide lattice formation enthalpy (ΔH(L)) and metal ionic radius are the best predictors of IXZO oxygen getter efficacy.

  17. Characterization and Testing of Improved Hydrogen Getter Materials - FY16 Annual Report

    SciTech Connect

    Hubbard, Kevin Mark; Sandoval, Cynthia Wathen

    2016-11-07

    Organic-based hydrogen getter materials have been in use for many years. These materials are able to prevent the dangerous buildup of hydrogen gas in sealed containers, and are also used to protect surrounding materials from degradation caused by chemical reactions. This document describes these materials.

  18. Deposition and Characterization of Improved Hydrogen Getter Materials - Report on FY 14-15 Activities

    SciTech Connect

    Hubbard, Kevin Mark; Sandoval, Cynthia Wathen

    2015-10-15

    The goals of this work have been two-fold. First, to perform an initial, quantitative, optimization of getter performance, with the primary variables being DEB/Pd ratio and UV power. Second, to simplify the deposition process to make it more compatible with the DOE production environment.

  19. The rate-limiting mechanism of transition metal gettering in multicrystalline silicon

    SciTech Connect

    McHugo, S.A.; Thompson, A.C.; Imaizumi, M.

    1997-04-01

    Multicrystalline silicon is a very interesting material for terrestrial solar cells. Its low cost and respectable energy conversion efficiency (12-15%) makes it arguably the most cost competitive material for large-volume solar power generation. However, the solar cell efficiency of this material is severely degraded by regions of high minority carrier recombination which have been shown to possess both dislocations and microdefects. These structural defects are known to increase in recombination activity with transition metal decoration. Therefore, gettering of metal impurities from the material would be expected to greatly enhance solar cell performance. Contrary to this rationale, experiments using frontside phosphorus and/or backside aluminum treatments have been found to improve regions with low recombination activity while having little or no effect on the high recombination regions and in turn only slightly improving the overall cell performance. The goal of this research is to determine the mechanism by which gettering is ineffectual on these high recombination regions. The authors have performed studies on integrated circuit (IC) quality single crystal and multicrystalline solar cell silicon (mc-silicon) in the as-grown state and after a variety of processing/gettering steps. With Surface Photovoltage measurements of the minority carrier diffusion length which is inversely proportional to carrier recombination, they have seen that aluminum gettering is effective for improving IC quality material but ineffective for improving the regions of initially low diffusion lengths (high recombination rates) in mc-silicon. Of particular interest is the great increase in diffusion length for IC material as compared to the mc-silicon. Clearly the IC material has benefited to a greater extent from the gettering procedure than the mc-silicon.

  20. Gettering of donor impurities by V in GaAs and the growth of semi-insulating crystals

    NASA Technical Reports Server (NTRS)

    Ko, K. Y.; Lagowski, J.; Gatos, H. C.

    1989-01-01

    Vanadium added to the GaAs melt getters shallow donor impurities (Si and S) and decreases their concentration in the grown crystals. This gettering is driven by chemical reactions in the melt rather than in the solid. Employing V gettering, reproducibly semi-insulating GaAs were grown by horizontal Bridgman and liquid-encapsulated Czochralski techniques, although V did not introduce any midgap energy levels. The compensation mechanism in these crystals was controlled by the balance between the native midgap donor EL2 and residual shallow acceptors. Vanadium gettering contributed to the reduction of the concentration of shallow donors below the concentration of acceptors. The present findings clarify the long-standing controversy on the role of V in achieving semi-insulating GaAs.

  1. Selection and Testing of "Getters" for Adsorption of Iodine-129 and Technetium-99: A Review

    SciTech Connect

    Mattigod, Shas V.; Serne, R. Jeffrey; Fryxell, Glen E.

    2003-09-24

    During the last several decades considerable research effort has been expended to identify suitable "getter" materials that can immobilize or delay the transport of anionic radionuclides (such as 129I and 99TcO4) that would be released from physically and chemically degrading waste packages. Several investigators have identified a number of important performance characteristics such as adsorption potential and chemical/physical stability that getter materials should possess for effective deployment in repository environments. A review of published literature indicated that various minerals and synthetic adsorbent materials such as, oxides, hydroxides, natural and modified aluminosilicates, sulfides, carbonates, phosphates, carbon, and functionalized novel sorbents have been tested for their getter properties. Oxide/hydroxide solids and many silicate minerals have poor capacity and selectivity for iodide (Kd : 0 – 10 ml/g) and release iodide with increasing pH. A few silicate minerals such as illite exhibit better selectivity for iodide (Kd : ~30 ml/g). Significantly improved iodide selectivity (Kd : 5,000 ml/g) has been observed with organically-modified silicate minerals such as montmorillonite and vermiculite. Sulfide minerals such as cinnabar and argentite typically adsorb iodide with very high selectivity (Kd : 3,000 – 80,000 ml/g). Synthetic materials such as calcium monosulfate aluminate and hydrotalcite show moderate iodide selectivity (Kd: ~25 – 300 ml/g). A new class of specially-designed synthetic getters when tested in groundwater and simulated waste package leachate adsorbed iodide with very high specificity (Kd: 100,000 – 1,000,000 ml/g). The long-term stability of these mineral and synthetic getters in post-closure environment needs further evaluation. Under oxic conditions and in groundwater or background salt solution, many of the oxide/ hydroxide solids and silicate minerals exhibit relatively poor capacity and selectivity (Kd: <5 ml/g) for

  2. WORKSHOP ON DEVELOPMENT OF RADIONUCLIDE GETTERS FOR THE YUCCA MOUNTAIN WASTE REPOSITORY

    SciTech Connect

    K.C. Holt

    2006-03-13

    One of the important that the U.S. Department of Energy (DOE) is currently undertaking is the development of a high-level nuclear waste repository to be located at Yucca Mountain, Nevada. Concern is generated by the Yucca Mountain Project (YMP) is due to potential releases as groundwater contamination, as described in the Total System Performance Assessment (TSPA). The dose to an off-site individual using this groundwater for drinking and irrigation is dominated by four radionuclides: Tc-99, I-127, Np-237, and U-238. Ideally, this dose would be limited to a single radionuclide, U-238; in other words, YMP would resemble a uranium ore body, a common geologic feature in the Western U.S. For this reason and because of uncertainties in the behavior of Tc-99, I-127, and Np-237, it would be helpful to limit the amount of Tc, I, and Np leaving the repository, which would greatly increase the confidence in the long-term performance of YMP. An approach to limiting the migration of Tc, I, and Np that is complementary to the existing YMP repository design plans is to employ sequestering agents or ''getters'' for these radionuclides such that their migration is greatly hindered, thus decreasing the amount of radionuclide leaving the repository. Development of such getters presents a number of significant challenges. The getter must have a high affinity and high selectivity for the radionuclide in question since there is approximately a 20- to 50-fold excess of other fission products and a 1000-fold excess of uranium in addition to the ions present in the groundwater. An even greater challenge is that the getters must function over a period greater than the half-life of the radionuclide (greater than 5 half-lives would be ideal). Typically, materials with a high affinity for Tc, I, or Np are not sufficiently durable. For example, strong-base ion exchange resins have a very high affinity for TcO{sub 4}{sup -} but are not expected to be durable. On the other hand, durable

  3. Method for absorbing hydrogen using an oxidation resisant organic hydrogen getter

    DOEpatents

    Shepodd, Timothy J.; Buffleben, George M.

    2009-02-03

    A composition for removing hydrogen from an atmosphere, comprising a mixture of a polyphenyl ether and a hydrogenation catalyst, preferably a precious metal catalyst, and most preferably platinum, is disclosed. This composition is stable in the presence of oxygen, will not polymerize or degrade upon exposure to temperatures in excess of 200.degree. C., or prolonged exposure to temperatures in the range of 100-300.degree. C. Moreover, these novel hydrogen getter materials can be used to efficiently remove hydrogen from mixtures of hydrogen/inert gas (e.g., He, Ar, N.sub.2), hydrogen/ammonia atmospheres, such as may be encountered in heat exchangers, and hydrogen/carbon dioxide atmospheres. Water vapor and common atmospheric gases have no adverse effect on the ability of these getter materials to absorb hydrogen.

  4. QED-1 device and measurements of gettering efficiency for a simulated divertor plasma

    SciTech Connect

    Owens, D.K.; Yamada, M.

    1980-03-01

    The QED-1 device at PPL has provided gettering efficiency data for neutralized hydrogen plasma on titanium. The hollow-anode arcjet produces a plasma column 1 cm in diameter with 10/sup 12/ < n/sub e/ < 10/sup 15/ cm/sup -3/ and T/sub i/ approx.< T/sub e/ = 3-10 eV, confined by an axial magnetic field of 1-6 kG. The gettering measurements are based on monitoring neutral gas density with respect to time in the divertor simulation chamber of QED-1. The present results indicate that the plasma particles lose their charge and most of their energy when they strike the neutralizer plate.

  5. Intrinsic Gettering of RIE Damage on Silicon Studied by Scanning DLTS and EBIC Methods

    NASA Astrophysics Data System (ADS)

    Ikuta, Kenji

    1987-07-01

    The degradation of silicon substrates due to reactive ion etching (RIE) damage and its elimination by intrinsic gettering (IG) are studied using scanning DLTS (SDLTS) and EBIC methods in an SEM. The SDLTS study clarifies that a hole trap of Ev+0.37 eV is introduced uniformly by RIE. Surface stacking faults are grown from latent defects associated with the trap during subsequent annealing. The EBIC analysis can predict macroscopic lifetime degradation due to the defect generation. IG is found to be successful in eliminating the degradation, when subsequent annealing is performed in O2, but not successful in N2 annealing. The gettering mechanism for RIE damage is also discussed in terms of the dependence on the annealing ambient.

  6. Method for gettering organic, inorganic and elemental iodine in aqueous solutions

    DOEpatents

    Beahm, Edward C.; Shockley, William E.

    1990-07-03

    A process for the removal of iodine from aqueous solutions, particularly the trapping of radioactive iodine to mitigate damage resulting from accidents or spills associated with nuclear reactors, by exposing the solution to well dispersed silver carbonate which reacts with the iodine and iodides, thereby gettering iodine and iodine compounds from solution. The iodine is not only removed from solution but also from the contiguous vapor.

  7. Method for gettering organic, inorganic and elemental iodine in aqueous solutions

    DOEpatents

    Beahm, Edward C.; Shockley, William E.

    1990-01-01

    A process for the removal of iodine from aqueous solutions, particularly the trapping of radioactive iodine to mitigate damage resulting from accidents or spills associated with nuclear reactors, by exposing the solution to well dispersed silver carbonate which reacts with the iodine and iodides, thereby gettering iodine and iodine compounds from solution. The iodine is not only removed from solution but also from the contiguous vapor.

  8. Assessment of Zr-Fe-V getter alloy for gas-gap heat switches

    NASA Technical Reports Server (NTRS)

    Prina, M.; Kulleck, J. G.; Bowman, R. C., Jr.

    2000-01-01

    A commercial Zr-V-Fe alloy (i.e., SAES Getters trade name alloy St-172) has been assessed as reversible hydrogen storage material for use in actuators of gas gap heat switches. Two prototype actuators containing the SAES St-172 material were built and operated for several thousand cycles to evaluate performance of the metal hydride system under conditions simulating heat switch operation.

  9. Carbon monoxide formation in UO 2 kerneled HTR fuel particles containing oxygen getters

    NASA Astrophysics Data System (ADS)

    Proksch, E.; Strigl, A.; Nabielek, H.

    1986-06-01

    Mass spectrometric measurements of CO in irradiated UO 2 kerneled HTR fuel particles containing various oxygen getters are summarized and evaluated. Uranium carbide addition in the 3 to 15% range reduces the CO release by factors between 25 and 80, up to burn-up levels as high as 70% FIMA. Unintentional gettering by SiC in TRISO coated particles with failed inner pyrocarbon layers results in CO reduction factors between 15 and 110. For ZrC, only somewhat ambiguous results have been obtained; most likely, ZrC results in CO reduction by a factor of about 40. Ce 2O 3 and La 2O 3 seem to be somewhat less effective than the three carbides; for Ce 2O 3, reduction factors between 3 and 15 have been found. However, these results are possibly incorrect due to premature oxidation of the getter already during fabrication. Addition of SiO 2 + Al 2O 3 has no influence on CO release at all.

  10. Effect of gamma irradiation on MnO2/Ag2O hydrogen getter

    NASA Astrophysics Data System (ADS)

    Chlique, Christophe; Lambertin, David; Galliez, Kévin; Labed, Véronique; Dannoux-Papin, Adeline; Jobic, Stéphane; Deniard, Philippe; Leoni, Elisa

    2015-03-01

    This study aims to show the stability of γ-MnO2/Ag2O hydrogen getter under gamma irradiation in order to be suitable for decreasing the hydrogen risk during the nuclear waste transportation. The chemical and the structural properties of the getter were barely unchanged for irradiated doses up to 4 MGy. The pair distribution function (PDF) analysis showed that the γ-MnO2, which can be describe as an intergrowth of the ramsdellite phase (R-MnO2) and the pyrolusite phase (β-MnO2), had the same intergrowth rate (around 60% for β-MnO2 and 40% for R-MnO2) after irradiation and the silver containing promoter was also unchanged. The getter remains therefore efficient for hydrogen trapping. Furthermore, γ-MnO2/Ag2O was tested in a closed environment in the presence of hydrogen released by organic technological waste radiolysis, such as polyvinyl chloride, ion exchange resins, polyethylene and silicone. Over 80% of the hydrogen, generated by organic radiolysis, was trapped under a 1.5 MGy gamma irradiation.

  11. Films.

    ERIC Educational Resources Information Center

    Philadelphia Board of Education, PA. Div. of Instructional Materials.

    The Affective Curriculum Research Project produced five films and two records during a series of experimental summer programs. The films and records form part of a curriculum designed to teach to the concerns of students. The films were an effort to describe the Philadelphia Cooperative Schools Program, to explain its importance, and to…

  12. Synthesis and properties of ferromagnetic nanostructures embedded within a high-quality crystalline silicon matrix via ion implantation and nanocavity assisted gettering processes

    SciTech Connect

    Malladi, Girish; Huang, Mengbing Murray, Thomas; Novak, Steven; Matsubayashi, Akitomo; LaBella, Vincent; Bakhru, Hassaram

    2014-08-07

    Integrating magnetic functionalities with silicon holds the promise of developing, in the most dominant semiconductor, a paradigm-shift information technology based on the manipulation and control of electron spin and charge. Here, we demonstrate an ion implantation approach enabling the synthesis of a ferromagnetic layer within a defect free Si environment by exploiting an additional implant of hydrogen in a region deep below the metal implanted layer. Upon post-implantation annealing, nanocavities created within the H-implanted region act as trapping sites for gettering the implanted metal species, resulting in the formation of metal nanoparticles in a Si region of excellent crystal quality. This is exemplified by the synthesis of magnetic nickel nanoparticles in Si implanted with H{sup +} (range: ∼850 nm; dose: 1.5 × 10{sup 16 }cm{sup −2}) and Ni{sup +} (range: ∼60 nm; dose: 2 × 10{sup 15 }cm{sup −2}). Following annealing, the H implanted regions populated with Ni nanoparticles of size (∼10–25 nm) and density (∼10{sup 11}/cm{sup 2}) typical of those achievable via conventional thin film deposition and growth techniques. In particular, a maximum amount of gettered Ni atoms occurs after annealing at 900 °C, yielding strong ferromagnetism persisting even at room temperature, as well as fully recovered crystalline Si environments adjacent to these Ni nanoparticles. Furthermore, Ni nanoparticles capsulated within a high-quality crystalline Si layer exhibit a very high magnetic switching energy barrier of ∼0.86 eV, an increase by about one order of magnitude as compared to their counterparts on a Si surface or in a highly defective Si environment.

  13. Synthesis and properties of ferromagnetic nanostructures embedded within a high-quality crystalline silicon matrix via ion implantation and nanocavity assisted gettering processes

    NASA Astrophysics Data System (ADS)

    Malladi, Girish; Huang, Mengbing; Murray, Thomas; Novak, Steven; Matsubayashi, Akitomo; LaBella, Vincent; Bakhru, Hassaram

    2014-08-01

    Integrating magnetic functionalities with silicon holds the promise of developing, in the most dominant semiconductor, a paradigm-shift information technology based on the manipulation and control of electron spin and charge. Here, we demonstrate an ion implantation approach enabling the synthesis of a ferromagnetic layer within a defect free Si environment by exploiting an additional implant of hydrogen in a region deep below the metal implanted layer. Upon post-implantation annealing, nanocavities created within the H-implanted region act as trapping sites for gettering the implanted metal species, resulting in the formation of metal nanoparticles in a Si region of excellent crystal quality. This is exemplified by the synthesis of magnetic nickel nanoparticles in Si implanted with H+ (range: ˜850 nm; dose: 1.5 × 1016 cm-2) and Ni+ (range: ˜60 nm; dose: 2 × 1015 cm-2). Following annealing, the H implanted regions populated with Ni nanoparticles of size (˜10-25 nm) and density (˜1011/cm2) typical of those achievable via conventional thin film deposition and growth techniques. In particular, a maximum amount of gettered Ni atoms occurs after annealing at 900 °C, yielding strong ferromagnetism persisting even at room temperature, as well as fully recovered crystalline Si environments adjacent to these Ni nanoparticles. Furthermore, Ni nanoparticles capsulated within a high-quality crystalline Si layer exhibit a very high magnetic switching energy barrier of ˜0.86 eV, an increase by about one order of magnitude as compared to their counterparts on a Si surface or in a highly defective Si environment.

  14. Intrinsic instability of thin liquid films on nanostructured surfaces

    NASA Astrophysics Data System (ADS)

    Rokoni, Arif; Hu, Han; Sun, Liyong; Sun, Ying

    2016-11-01

    The instability of a thin liquid film on nanostructures is not well understood but is important in liquid-vapor two-phase heat transfer (e.g., thin film evaporation and boiling), lubrication, and nanomanufacturing. In thin film evaporation, the comparison between the non-evaporating film thickness and the critical film breakup thickness determines the stability of the film: the film becomes unstable when the critical film breakup thickness is larger than the non-evaporating film thickness. In this study, a closed-form model is developed to predict the critical breakup thickness of a thin liquid film on 2D periodic nanostructures based on minimization of system free energy in the limit of a liquid monolayer. Molecular dynamics simulations are performed for water thin films on square nanostructures of varying depth and wettability and the simulations agree with the model predictions. The results show that the critical film breakup thickness increases with the nanostructure depth and the surface wettability. The model developed here enables the prediction of the minimum film thickness for stable thin film evaporation on a given nanostructure.

  15. Intrinsic instability of thin liquid films on nanostructured surfaces

    NASA Astrophysics Data System (ADS)

    Sun, L.; Hu, H.; Rokoni, A. A.; Sun, Y.

    2016-09-01

    The instability of a thin liquid film on nanostructures is not well understood but is important in liquid-vapor two-phase heat transfer (e.g., thin film evaporation and boiling), lubrication, and nanomanufacturing. In thin film evaporation, the comparison between the non-evaporating film thickness and the critical film breakup thickness determines the stability of the film: the film becomes unstable when the critical film breakup thickness is larger than the non-evaporating film thickness. In this study, a closed-form model is developed to predict the critical breakup thickness of a thin liquid film on 2D periodic nanostructures based on the minimization of system free energy in the limit of a liquid monolayer. Molecular dynamics simulations are performed for water thin films on square nanostructures of varying depth and wettability, and the simulations agree with the model predictions. The results show that the critical film breakup thickness increases with the nanostructure depth and the surface wettability. The model developed here enables the prediction of the minimum film thickness for a stable thin film evaporation on a given nanostructure.

  16. Films

    NASA Astrophysics Data System (ADS)

    Li, Ming; Zhang, Yang; Shao, Yayun; Zeng, Min; Zhang, Zhang; Gao, Xingsen; Lu, Xubing; Liu, J.-M.; Ishiwara, Hiroshi

    2014-09-01

    In this paper, we investigated the microstructure and electrical properties of Bi2SiO5 (BSO) doped SrBi2Ta2O9 (SBT) films deposited by chemical solution deposition. X-ray diffraction observation indicated that the crystalline structures of all the BSO-doped SBT films are nearly the same as those of a pure SBT film. Through BSO doping, the 2Pr and 2Ec values of SBT films were changed from 15.3 μC/cm2 and 138 kV/cm of pure SBT to 1.45 μC/cm2 and 74 kV/cm of 10 wt.% BSO-doped SBT. The dielectric constant at 1 MHz for SBT varied from 199 of pure SBT to 96 of 10 wt.% BSO-doped SBT. The doped SBT films exhibited higher leakage current than that of non-doped SBT films. Nevertheless, all the doped SBT films still had small dielectric loss and low leakage current. Our present work will provide useful insights into the BSO doping effects to the SBT films, and it will be helpful for the material design in the future nonvolatile ferroelectric memories.

  17. Strong segregation gettering of transition metals by implantation-formed cavities and boron-silicide precipitates in silicon

    SciTech Connect

    Myers, S.M.; Petersen, G.A.; Follstaedt, D.M.; Headley, T.J.

    1996-06-01

    We have mechanistically and quantitatively characterized the binding of transition-metal impurities in Si to cavities formed by He implantation and to B-Si precipitates resulting from B implantation. Both sinks are inferred to act by the segregation of metal atoms to pre-existing low-energy sites, namely surface chemisorption sites in the case of cavities and bulk solution sites in the case of the B-Si phase. These gettering processes exhibit large binding energies, and they are predicted to remain active for arbitrarily small initial impurity concentrations as a result of the segregation mechanisms. Both appear promising for gettering in Si devices.

  18. EFFECT OF THERMAL PROCESSES ON COPPER-TIN ALLOYS FOR ZINC GETTERING

    SciTech Connect

    Korinko, P.; Golyski, M.

    2013-11-01

    A contamination mitigation plan was initiated to address the discovery of radioactive zinc‐65 in a glovebox. A near term solution was developed, installation of heated filters in the glovebox piping. This solution is effective at retaining the zinc in the currently contaminated area, but the gamma emitting contaminant is still present in a system designed for tritium beta. A project was initiated to develop a solution to contain the {sup 65}Zn in the furnace module. Copper and bronze (a Cu/Sn alloy) were found to be candidate materials to combine with zinc‐65 vapor, using thermodynamic calculations. A series of binary Cu/Sn alloys were developed (after determining that commercial alloys were unacceptable), that were found to be effective traps of zinc vapor. The task described in this report was undertaken to determine if the bronze substrates would retain their zinc gettering capability after being exposed to simulated extraction conditions with oxidizing and reducing gases. Pure copper and three bronze alloys were prepared, exposed to varying oxidation conditions from 250 to 450{degree}C, then exposed to varying reduction conditions in He-H{sub 2} from 250-450{degree}C, and finally exposed to zinc vapor at 350{degree}C for four hours. The samples were characterized using scanning electron microscopy, X-ray diffraction, differential thermal analysis, mass change, and visual observation. It was observed that the as fabricated samples and the reduced samples all retained their zinc gettering capacity while samples in the "as-oxidized" condition exhibited losses in zinc gettering capacity. Over the range of conditions tested, i.e., composition, oxidation temperature, and reduction temperature, no particular sample composition appeared better. Samples reduced at 350{degree}C exhibited the greatest zinc capacity, although there were some testing anomalies associated with these samples. This work clearly demonstrated that the zinc gettering was not adversely

  19. Purification of liquid metal systems with sodium coolant from oxygen using getters

    NASA Astrophysics Data System (ADS)

    Kozlov, F. A.; Konovalov, M. A.; Sorokin, A. P.

    2016-05-01

    For increasing the safety and economic parameters of nuclear power stations (NPSs) with sodium coolant, it was decided to install all systems contacting radioactive sodium, including purification systems of circuit I, in the reactor vessel. The performance and capacity of cold traps (CTs) (conventional element of coolant purification systems) in these conditions are limited by their volume. It was proposed to use hot traps (HTs) in circuit I for coolant purification from oxygen. It was demonstrated that, at rated parameters of the installation when the temperature of the coolant streamlining the getter (gas absorber) is equal to 550°C, the hot trap can provide the required coolant purity. In shutdown modes at 250-300°C, the performance of the hot trap is reduced by four orders of magnitude. Possible HT operation regimes for shutdown modes and while reaching rated parameters were proposed and analyzed. Basic attention was paid to purification modes at power rise after commissioning and accidental contamination of the coolant when the initial oxygen concentration in it reached 25 mln-1. It was demonstrated that the efficiency of purification systems can be increased using HTs with the getter in the form of a foil or granules. The possibility of implementing the "fast purification" mode in which the coolant is purified simultaneously with passing over from the shutdown mode to the rated parameters was substantiated.

  20. Molecular simulation on interfacial structure and gettering efficiency of direct silicon bonded (110)/(100) substrates

    NASA Astrophysics Data System (ADS)

    Kariyazaki, Hiroaki; Aoki, Tatsuhiko; Izunome, Koji; Sueoka, Koji

    2010-06-01

    Direct silicon bonded (DSB) substrates with (110)/(100) hybrid orientation technology are attracting considerable attention as a promising technology for high performance bulk complementary metal-oxide semiconductor technology. We have investigated the structure and the gettering efficiency of the (110)/(100) interface parallelling each ⟨110⟩ direction (DSB interface) by molecular dynamics (MD) and first-principles calculation. In MD calculations, initial calculation cells of 15 atomic-configurations with coincidence-site lattices were prepared. It was found that (i) the calculated DSB interface was stable independent of the initial atomic-configurations and (ii) the interfacial structures were essentially the same among the calculated models. Moreover, the calculated interfacial structure corresponds to the reported TEM observation. The first-principles calculation showed that Si atoms in the DSB interface formed covalent bonding. The dangling bonds in Si (110) and (100) surfaces disappeared due to restructuring in the DSB interface. Furthermore, the DSB interface, which exists just below the device active region, was found to be an efficient gettering site for Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Hf atoms.

  1. Performance of Zr-Al getter pumps under transient load conditions

    SciTech Connect

    Emerson, L.C.; Mioduszewski, P.K.; Simpkins, J.E.

    1983-01-01

    Testing of the pump limiter concept in the Impurity Study Experiment (ISX-B) tokamak will involve the use of Zr-Al nonevaporable getter pumps capable of handling intermittent pulses of hydrogen and/or deuterium in the presence of carbon and oxygen impurity concentrations of several percent. To study the pumping characteristics under these conditions we have installed a Zr-Al cartridge pump in a vacuum chamber equipped with a fast gas puff feed system, a quadrupole residual gas analyzer, and a high speed ion gauge for transient pressure measurements. In this paper we report on the performance of the pump over a wide range of gas loads up to that sufficient to provide tens of monolayers coverage of the getter surface. With flow rates up to 13 torr L/s, pumping speeds for hydrogen were measured to be 1200-1500 L/s at pressures up to 10 mtorr. The measurements were carried out with gas pulses ranging in length from 50 ms to over 1 s and under conditions that provided a constant pumping speed for impurity species.

  2. Mechanical grooving effect on the gettering efficiency of crystalline silicon based solar cells

    NASA Astrophysics Data System (ADS)

    Zarroug, Ahmed; Hamed, Zied Ben; Derbali, Lotfi; Ezzaouia, Hatem

    2017-04-01

    This paper examines a gettering process of Czochralski silicon (CZ) via mechanical texture, followed by two step heat treatment in the presence of porous silicon layer (PSL) under oxygen flow gas. It is shown that a process with PS has a positive trend of improvement in the electronic quality, and found to be more efficient when used in combination with mechanical grooving. We obtained a significant increase of the effective minority carrier lifetime and majority charge carriers mobility. Thus, there is an apparent decrease in the resistivity. These parameters were estimated through a The Quasi-Steady-State Photo-Conductance technique (QSSPC), the van Der Pauw method and Hall Effect. Particularly, we have made obvious that the large enhancement of the electronic quality of the wafers can be related to the presence of grooves, the influence during which the gettering process is of importance to overcome the unexpected saturation phenomena. The current voltage I-V characteristics of all samples had been measured under illumination. They were shown to enhance the photovoltaic properties of solar cells.

  3. Characterization Of The Hydrogenation Products Of Bix (phenylethynyl) Benzene (DEB) Getter Using Combined GC/FTIR/MS, FT-Raman, and ATR Spectroscopies (U)

    SciTech Connect

    Smyrl, N. R.; Powell, G. L.

    2011-06-09

    Organic hydrogen getters are utilized to minimize hydrogen accumulation in sealed systems where such build up could produce either a safety problem from pressure build up or corrosion problem due the hydriding of metals contained in the sealed vessel. DEB (1,4 bis (phenyl ethynyl) benzene) is a hydrogen getter that is based on the palladium catalyzed hydrogenation of triple bonds to single bonds in aromatic aryl compound. DEB is a getter mixed with 25% carbon and 1% Pd and pressed into pellets with some porosity. The reaction mechanisms are complex involving solid state reactions with a heterogeneous catalyst leading to the many intermediates.

  4. Three-dimensional evaluation of gettering ability for oxygen atoms at small-angle tilt boundaries in Czochralski-grown silicon crystals

    SciTech Connect

    Ohno, Yutaka Inoue, Kaihei; Fujiwara, Kozo; Deura, Momoko; Kutsukake, Kentaro; Yonenaga, Ichiro; Shimizu, Yasuo; Inoue, Koji; Ebisawa, Naoki; Nagai, Yasuyoshi

    2015-06-22

    Three-dimensional distribution of oxygen atoms at small-angle tilt boundaries (SATBs) in Czochralski-grown p-type silicon ingots was investigated by atom probe tomography combined with transmission electron microscopy. Oxygen gettering along edge dislocations composing SATBs, post crystal growth, was observed. The gettering ability of SATBs would depend both on the dislocation strain and on the dislocation density. Oxygen atoms would agglomerate in the atomic sites under the tensile hydrostatic stress larger than about 2.0 GPa induced by the dislocations. It was suggested that the density of the atomic sites, depending on the tilt angle of SATBs, determined the gettering ability of SATBs.

  5. Screening protocol for iodine-specific getters in YMP-related invert applications.

    SciTech Connect

    Krumhansl, James Lee; Pless, Jason; Chwirka, J. Benjamin

    2006-07-01

    This document defines a standardized screening protocol for use in developing iodine ''getters'' for placement in the proposed YMP-repository invert. The work was funded by the US Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), Office of Science and Technology International (S&T) during 2004-2005. First, the likely environmental conditions in the invert are reviewed as a basis for defining the thermal and geochemical regimes in which a getter must function. These considerations, then, served as the basis for laying out a hierarchy of materials screening tests (Table 1). An experimental design for carrying out these screening tests follows next. Finally, the latter half of the document develops methods for preparing test solutions with chemistries that relate to various aspects of the YMP-repository environment (or, at least to such representations as were available from program documents late in 2004). Throughout the document priority was given to defining procedures that would quickly screen out unpromising candidate materials with a minimum amount of labor. Hence, the proposed protocol relies on batch tests over relatively short times, and on a hierarchy of short pre-test conditioning steps. So as not to repeat the mistakes (and frustrations) encountered in the past (notably in preparing WIPP test brines) particular care was also given to developing standardized test solution recipes that could be prepared easily and reproducibly. This document is principally intended for use as a decision-making tool in evaluating and planning research activities. It is explicitly NOT a roadmap for qualifying getters for actual placement in the repository. That would require a comprehensive test plan and a substantial consensus building effort. This document is also not intended to provide a complete list of all the tests that individuals may wish to carry out. Various materials will have their own peculiar concerns that will call for

  6. Screening Protocol for Iodine-Specific Getters in YMP-Related Invert Applications

    SciTech Connect

    J.L. Krumhansl; J.D. Pless; J.B. Chwirka

    2006-07-17

    This document defines a standardized screening protocol for use in developing iodine ''getters'' for placement in the proposed YMP-repository invert. The work was funded by the US Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), Office of Science and Technology International (S&T) during 2004-2005. First, the likely environmental conditions in the invert are reviewed as a basis for defining the thermal and geochemical regimes in which a getter must function. These considerations, then, served as the basis for laying out a hierarchy of materials screening tests (Table 1). An experimental design for carrying out these screening tests follows next. Finally, the latter half of the document develops methods for preparing test solutions with chemistries that relate to various aspects of the YMP-repository environment (or, at least to such representations as were available from program documents late in 2004). Throughout the document priority was given to defining procedures that would quickly screen out unpromising candidate materials with a minimum amount of labor. Hence, the proposed protocol relies on batch tests over relatively short times, and on a hierarchy of short pre-test conditioning steps. So as not to repeat the mistakes (and frustrations) encountered in the past (notably in preparing WIPP test brines) particular care was also given to developing standardized test solution recipes that could be prepared easily and reproducibly. This document is principally intended for use as a decision-making tool in evaluating and planning research activities. It is explicitly NOT a roadmap for qualifying getters for actual placement in the repository. That would require a comprehensive test plan and a substantial consensus building effort. This document is also not intended to provide a complete list of all the tests that individuals may wish to carry out. Various materials will have their own peculiar concerns that will call for

  7. Simple self-gettering differential-pump for minimizing source oxidation in oxide-MBE environment

    SciTech Connect

    Kim, Yong-Seung; Bansal, Namrata; Oh, Seongshik

    2011-07-15

    Source oxidation of easily oxidizing elements such as Ca, Sr, Ba, and Ti in an oxidizing ambient leads to their flux instability and is one of the biggest problems in the multielemental oxide molecular beam epitaxy technique. Here, the authors report a new scheme that can completely eliminate the source oxidation problem: a self-gettering differential pump using the source itself as the pumping medium. The pump simply comprises a long collimator mounted in front of the source in extended port geometry. With this arrangement, the oxygen partial pressure near the source was easily maintained well below the source oxidation regime, resulting in a stabilized flux, comparable to that of an ultrahigh-vacuum environment. Moreover, this pump has a self-feedback mechanism that allows a stronger pumping effectiveness for more easily oxidizing elements, which is a desired property for eliminating the source oxidation problem.

  8. Experiences from nonevaporable getter-coated vacuum chambers at the MAX II synchrotron light source

    SciTech Connect

    Hansson, A.; Wallen, E.; Berglund, M.; Kersevan, R.; Hahn, M.

    2010-03-15

    Vacuum chambers coated with nonevaporable getter (NEG) materials have been used in straight sections of synchrotron light sources for the past 10 years. The MAX II storage ring, where four NEG-coated insertion device vacuum chambers and three NEG-coated dipole vacuum chambers have been installed, is the first synchrotron light source to also use NEG-coated dipole vacuum chambers. In connection with the installation of the latest two NEG-coated dipole chambers in April 2009, the evolution of the pressure and lifetime-limiting effects in MAX II has been determined from measurements with movable scrapers. The results have been compared with results from scraper measurements done in 2003, before any NEG-coated vacuum chambers were installed in the storage ring. Less than three months after the installation of the latest dipole chambers the vacuum system in MAX II was performing well with a pressure already lower than the pressure measured in 2003.

  9. Evaluation of RTV as a Moldable Matrix When Combined With Molecular Sieve and Organic Hydrogen Getter

    SciTech Connect

    Knight, J. A.

    2011-12-01

    This work was undertaken in an effort to develop a combined RTV 615/3Å molecular sieve/DEB molded component. A molded RTV 615/3Å molecular sieve component is currently in production, and an RTV 615/DEB component was produced in the past. However, all three materials have never before been combined in a single production part, and this is an opportunity to create a new component capable of being molded to shape, performing desiccation, and hydrogen gettering. This analysis looked at weapons system parameters and how they might influence part design. It also looked at material processing and how it related to mixing, activating a dessicant, and hydrogen uptake testing.

  10. Workshop on development of radionuclide getters for the Yucca Mountain waste repository: proceedings.

    SciTech Connect

    Moore, Robert Charles; Lukens, Wayne W. (Lawrence Berkeley National Laboratory)

    2006-03-01

    The proposed Yucca Mountain repository, located in southern Nevada, is to be the first facility for permanent disposal of spent reactor fuel and high-level radioactive waste in the United States. Total Systems Performance Assessment (TSPA) analysis has indicated that among the major radionuclides contributing to dose are technetium, iodine, and neptunium, all of which are highly mobile in the environment. Containment of these radionuclides within the repository is a priority for the Yucca Mountain Project (YMP). These proceedings review current research and technology efforts for sequestration of the radionuclides with a focus on technetium, iodine, and neptunium. This workshop also covered issues concerning the Yucca Mountain environment and getter characteristics required for potential placement into the repository.

  11. Metal gettering by boron-silicide precipitates in boron-implanted silicon

    SciTech Connect

    Myers, S.M.; Petersen, G.A.; Headley, T.J.; Michael, J.R.; Aselage, T.A.; Seager, C.H.

    1996-09-01

    We show that Fe, Co, Cu, and Au impurities in Si are strongly gettered to boron-silicide precipitates formed by supersaturation B implantation and annealing. Effective binding free energies relative to interstitial solution range form somewhat above 1 to more than 2 eV. The B-Si precipitates formed at temperatures {le}1100{degrees}C lack long range structural order but closely resemble and icosahedral B{sub 3}Si phase in composition, local bonding, and chemical potential. Evidence indicates that the metal atoms go into solution in the B-Si phase, and this is interpreted in terms of the novel bonding and structural characteristics of B-rich icosahedral compounds.

  12. Absorption/desorption of hydrogen isotopes and isotopic waters by Zr-alloy getters

    SciTech Connect

    Ichimura, K.; Matsuyama, M.; Watanabe, K.; Takeuchi, T.

    1988-07-01

    Zr-alloy getters have been applied to tritium handling and vacuum conditioning for fusion devices. Some of their properties, however, should be improved to apply them in future devices. From this viewpoint, we have studied the effects of alloying on the getter properties of Zr alloys. We found that the activation energy of absorption and desorption of hydrogen varied considerably with alloying. The activation energy for hydrogen absorption was 0.74 for Zr/sub 61/Al/sub 39/, 0.01 for Zr/sub 57/V/sub 36/Fe/sub 7/, 0.63 for Zr/sub 67/Ni/sub 33/, and 2.8 kcal/mol for Zr/sub 85/Ni/sub 15/, whereas that for Zr was 2.6 kcal/mol. The heat of hydrogen absorption was 27.8 kcal/mol for Zr: it changed with alloying as 32.0--33.4 (Zr/sub 61/Al/sub 39/), 27.8--28.4 (Zr/sub 57/V/sub 36/Fe/sub 7/), 29.0 (Zr/sub 67/Ni/sub 33/), and 28.0 (Zr/sub 85/Ni/sub 15/). In addition, the ratio of the pumping speed of water vapor to that of hydrogen at room temperature varied with alloying element: for example, 1/40 for Zr/sub 57/V/sub 36/Fe/sub 7/ and 1/4 for Zr/sub 67/Ni/sub 33/. The alloying effects mentioned above are considered due to modification of the electronic and/or geometric structure of Zr with alloying.

  13. An investigation of the gettering properties of silicon-germanium and silicon-carbon compounds

    SciTech Connect

    Barbero, C.J.

    1993-01-01

    Work concerning silicon-germanium (SiGe) and silicon-carbon (SiC) compounds is presented in this dissertation. Extended Hueckel (EHT) parameters for the band structure of group IV semiconductors and semiconductor compounds are put forth using established parameters. It will be demonstrated that EHT theory can accurately predict the band structure for the pure group IV semiconductors, however provides notably unusual results for alloy systems. Relativistic Extended Hueckel (REX) Theory is employed to understand the outcome of transition metals in SiGe and SiC compounds. The gettering effect and efficiency of germanium and carbon is demonstrated by using a 54 atom cluster. SiGe and SiC samples were prepared using keV ion implantation. It was found that annealing germanium implanted samples constrains germanium in a substitutional position. The consequences of different doses and different energies for germanium implanted silicon is also explored. It is established that increasing energy as well as increasing dose has the effect of creating amorphous layers and can cause alloying. Some of the germanium implanted silicon samples were used to study the gettering of copper, which was evaporated on the backside of the samples. Further studies include keV ion implantation of transition metals (iron and nickel) into silicon substrates that were implanted with MeV germanium and carbon prior to keV (iron and nickel) implantation. The effects of transition metals (i.e., iron, nickel and copper) evaporated on ultrahigh vacuum-chemical vapor deposition (UHV-CVD) prepared SiGe compounds was also investigated. Techniques such as Rutherford Backscattering (RBS), Ion Channeling, Secondary Ion Mass Spectrometry (SIMS), Capacitance-Voltage (C-V) and Deep Level Transient Spectroscopy (DLTS) were used to study the effects of implantation energy, implantation dose and annealing temperature as well as the different results produced by introduction of several transition metals.

  14. Molecular dynamic simulation of platinum heater and associated nano-scale liquid argon film evaporation and colloidal adsorption characteristics.

    PubMed

    Maroo, Shalabh C; Chung, J N

    2008-12-01

    A novel 'fluid-wall thermal equilibrium model' for the wall-fluid heat transfer boundary condition has been developed in this paper to capture the nano-scale physics of transient phase transition of a thin liquid argon film on a heated platinum surface and the eventual colloidal adsorption phenomenon as the evaporation is diminishing using molecular dynamics. The objective of this work is to provide microscopic characterizations of the dynamic thermal energy transport mechanisms during the liquid film evaporation and also the resulting non-evaporable colloidal adsorbed liquid layer at the end of the evaporation process. A nanochannel is constructed of platinum (Pt) wall atoms with argon as the working fluid. The proposed model is validated by heating liquid argon between two Pt walls and comparing the thermal conductivity and change in internal energy to thermodynamic properties of argon. Later on, phase change process is studied by simulating evaporation of a thin liquid argon film on a Pt wall using the proposed model. Gradual evaporation of the liquid film occurs although the film does not vaporize completely. An ultra-thin layer of liquid argon is noticed to have "adsorbed" on the platinum surface. An analysis similar to the theoretical study by Hamaker (1937) is performed for the non-evaporating film and the value of the Hamaker-type constant falls in the typical range. This analysis is done to quantify the non-evaporating film with an attempt to use molecular dynamics simulation results in continuum mechanics.

  15. Improved Hydrogen Gas Getters for TRU Waste Transuranic and Mixed Waste Focus Area - Phase 2 Final Report

    SciTech Connect

    Stone, Mark Lee

    2002-04-01

    Alpha radiolysis of hydrogenous waste and packaging materials generates hydrogen gas in radioactive storage containers. For that reason, the Nuclear Regulatory Commission (NRC) limits the flammable gas (hydrogen) concentration in the Transuranic Package Transporter-II (TRUPACT-II) containers to 5 vol% of hydrogen in air, which is the lower explosion limit. Consequently, a method is needed to prevent the build up of hydrogen to 5 vol% during the storage and transport of the TRUPACT-II containers (up to 60 days). One promising option is the use of hydrogen getters. These materials scavenge hydrogen from the gas phase and irreversibly bind it in the solid phase. One proven getter is a material called 1,4-bis (phenylethynyl) benzene, or DEB. It has the needed binding rate and capacity, but some of the chemical species that might be present in the containers could interfere with its ability to remove hydrogen. This project is focused upon developing a protective polymeric membrane coating for the DEB getter material, which comes in the form of small, irregularly shaped particles. This report summarizes the experimental results of the second phase of the development of the materials.

  16. Method of forming metal hydride films

    NASA Technical Reports Server (NTRS)

    Steinberg, R.; Alger, D. L.; Cooper, D. W. (Inventor)

    1977-01-01

    The substrate to be coated (which may be of metal, glass or the like) is cleaned, both chemically and by off-sputtering in a vacuum chamber. In an ultra-high vacuum system, vapor deposition by a sublimator or vaporizer coats a cooled shroud disposed around the substrate with a thin film of hydride forming metal which getters any contaminant gas molecules. A shutter is then opened to allow hydride forming metal to be deposited as a film or coating on the substrate. After the hydride forming metal coating is formed, deuterium or other hydrogen isotopes are bled into the vacuum system and diffused into the metal film or coating to form a hydride of metal film. Higher substrate temperatures and pressures may be used if various parameters are appropriately adjusted.

  17. Combined Impact of Heterogeneous Lifetime and Gettering on Solar Cell Performance

    SciTech Connect

    Morishige, A.; Wagner, H.; Hofstetter, J.; Avci, I.; Canizo, C.; Buonassisi, T.

    2015-03-23

    We couple numerical process and device simulations to provide a framework for understanding the combined effects of as-grown wafer impurity distribution, processing parameters, and solar cell architecture. For this study, we added the Impurity-to-Efficiency simulator to Synopsys’ Sentaurus Process software using the Alagator Scripting Language. Our results quantify how advanced processing can eliminate differences in efficiency due to different as-grown impurity concentrations and due to different area fractions of defective wafer regions. We identify combinations of as-grown impurity distributions and process parameters that produce solar cells limited by point defects and those that are limited by precipitated impurities. Gettering targeted at either point defect or precipitate reduction can then be designed and applied to increase cell efficiency. We also visualize the post-processing iron and total recombination distributions in 2D maps of the wafer cross-section. PV researchers and companies can input their initial iron distributions and processing parameters into our software and couple the resulting process simulation results with a solar cell device design of interest to conduct their own analyses. The Alagator scripts we developed are freely available online at http://pv.mit.edu/impurity-to-efficiency-i2e-simulator-for-sentaurus-tcad/.

  18. Experimental investigation of the efficiency of HTO reduction by Zr-Fe-Mn getter alloy

    SciTech Connect

    Ghezzi, F.; Shmayda, W.T.; Bonizzoni, G.

    1997-01-01

    Tritium gas handling involves the production of tritiated water, which is 10000 times more hazardous than tritium gas. If tritium emission to the environment must be minimized, the need to process tritiated water and recover the chemically bound tritium appears clear. Facilities for processing tritiated water produced in fission reactors are already available, while facilities for a deuterium-tritium fusion machine are under development. However, these facilities are intended for large-scale applications and are neither practical nor economical for small-scale applications. HTO vapor reduction to HT over a hot metal getter other than uranium offers a simple, safe, and economical solution. A high alloy capacity and conversion rate combined with a low tritium residual inventory in the exhausted alloy make this method attractive. An experimental investigation of the efficiency of reducing HTO by a Zr-Fe-Mn alloy is presented. The results, obtained by three independent diagnostics (stripper set, ionization chambers, and mass spectrometry), show that for gas residence times > 1 s and alloy temperature > 400{degree}C, a conversion efficiency exceeding 90% is achievable. Specific conversion rates > 0.1 {mu}mol/s.g{sup -1} are observed during te alloy usage, while a capacity of the alloy, measured as an oxygen-to-alloy mole ratio, > 2.6 has been measured. 50 refs., 21 figs., 5 tabs.

  19. Complete Initial Scoping Tests on the Incorporation of Novel Loaded Iodine Getters into GCM.

    SciTech Connect

    Nenoff, Tina M.; Garino, Terry J.; Croes, Kenneth James

    2015-08-18

    This study encompasses initial scoping tests on the incorporation of a novel iodine loaded getter material into the Sandia developed low temperature sintering glass ceramic material (GCM) waste form. In particular, we studied the PNNL Ag-I-Aerogel. Optical microscopy indicates inhomogenous samples based on particle sizes and variations in color (AgI vs Ag/AgO on silica). TGA/MS data when heated in air indicates loss of iodine and organics (CO2) between 250-450°C a total of ~15wt% loss, with additional / small iodine loss when during 550°C hold for 1 hr. TGA/MS data when heated in N2 indicates less organic and slightly less iodine loss below 550°C, with no loss of iodine in 550°C 1 hour hold. Furthermore, a substantial mass loss of sulfur containing compounds is observed (m/e of 34 and 36) between 150 – 550°C in both air and N2 sintering atmospheres. In an effort to capture iodine lost to volatilization during heating (at temps below glass sintering temperature of 550°C), we added 5 wt% Ag flake to the AgIaerogel. Resulting data indicates the iodine is retained with the addition of the Ag flake, resulting in only a small iodine loss (< 1wt%) at ~350°C. No method of curtailing loss of sulfur containing compounds due to heating was successful in this scoping study.

  20. Yucca mountain project getter program results(year 1):I-129 and other anions of concern.

    SciTech Connect

    Krumhansl, James Lee; Pless, Jason; Chwirka, J. Benjamin

    2006-07-01

    Although high level nuclear wastes (HLW) contain a daunting array of radioisotopes, only a restricted number are long-lived enough to be problematic, and of these many are either effectively insoluble or are likely to be scavenged from solution by minerals indigenous to all aquifers. Those few constituents likely to travel significant distances through aquifers either form colloids (and travel as particulates) or anions--which are not sorbed onto the predominantly negatively charged mineral surfaces. Iodine ({sup 129}I) is one such constituent and may travel as either iodide (I{sup -}) or iodate (IO{sub 3}{sup -}) depending on whether conditions are mildly reducing or oxidizing. Conventionally, {sup 99}Tc (traveling as TcO{sub 4}{sup -}) is regarded as being of greater concern since it is both more abundant and has a shorter half life (e.g., has a higher specific activity). However, it is unclear whether TcO{sub 4}{sup -} will ever actually form in the mildly reducing environments thought likely within degrading HLW canisters. Instead, technetium may remain reduced as highly insoluble Tc(IV), in which case {sup 129}I might become a significant risk driver in performance assessment (PA) calculations. In the 2004-2005 time frame the US Department of Energy (DOE)--Office of Civilian Radioactive Waste Management (OCRUM), Office of Science and Technology International (S&T) funded a program to identify ''getters'' for possible placement in the invert beneath HLW packages in the repository being planned by the Yucca Mountain Project (YMP). This document reports on progress made during the first (and only) year of this activity. The problem is not a new one and the project did not proceed in a complete vacuum of information. Potential leads came from past studies directed at developing anion getters for a near surface low-level waste facility at Hanford, which suggested that both copper-containing compounds and hydrotalcite-group minerals might be promising. Later work

  1. Effect of Helium implantation on gettering and electrical properties of 4H-SiC epilayers

    SciTech Connect

    Biondo, Stephane; Regula, Gabrielle; Ottaviani, Laurent; Palais, Olivier; Pichaud, Bernard

    2011-01-07

    This paper tests the gettering ability of sites created by He implantation in 4H-SiC while heating the sample or not, and their impact on carrier lifetime. The spatial distribution of implantation-induced defects (cavities, stacking faults and dislocations) is studied by transmission electron microscopy (TEM) and is compared to gold profiles performed by Rutherford Backscattering (RBS) in samples intentionally contaminated with gold. Minority carrier lifetimes are also measured with a specific set-up based on microwave photoconductivity decay ({mu}-PCD). Though gold atoms do not seem to be efficiently trapped by cavities, the presence of dislocations is of major importance to monitor gold diffusion. Indeed, they can double both its level and its diffusion length in the bulk. Gold is assumed to diffuse faster along dislocation cores. Besides, the implantation-related defects are found to improve the carrier lifetime in the material, but the role of He{sup 2+} left in cavities remains to be investigated.

  2. Assessing materials (''Getters'') to immobilize or retard the transport of technetium through the engineered barrier system at the potential Yucca Mountain nuclear waste repository

    SciTech Connect

    Viani, B E

    1999-03-15

    Current performance assessment calculations show that technetium (Tc) and neptunium (Np) will deliver the major fraction of the radiation dose to the accessible environment from the potential Yucca Mountain nuclear waste repository. Therefore, materials that can immobilize or delay the transport of Tc or Np (getters) are being considered for addition to either the waste-package or the backfill adjacent to the waste-package. Of the two radionuclides, Tc presents the greater challenge in identifying a suitable getter material. This report identifies several materials that warrant further consideration for immobilizing and/or sorbing Tc as additives to the backfill, and recommends active carbon and an inorganic oxide for initial testing. Other materials, such as zero valent iron, might be useful as getters if they were placed in the waste package itself, a subject that merits further investigation.

  3. Surface characterization of a Zr--V--Fe getter by XPS-SIMS: activation process and D/sub 2/O exposure

    SciTech Connect

    Ichimura, K.; Ashida, K.; Watanabe, K.

    1985-03-01

    To apply hydrogen storage materials (getters) to tritium recovery and storage, it is important to understand the activation process of the getters and their pumping characteristics not only for tritium gas, but also impurity gases such as HTO. From this viewpoint, the activation process of the Zr--V--Fe getter (St-707, SAES Getters) and absorption process of D/sub 2/O were investigated with XPS-SIMS. An as-received getter surface was observed to be covered with H/sub 2/O, CO, O/sub 2/, and hydrocarbons. In addition, the getter components formed respective oxides on the surface. The activation, which consisted of vacuum heating above 500 /sup 0/C, caused the disappearance of the adsorbed impurities from the surface, forming a metallic surface consisting of Zr(87 at.%) and V(13 at.%). Exposure to D/sub 2/O vapor at 25 /sup 0/C resulted in the adsorption of D/sub 2/O as D/sub 2/O(a) and/or OD(a). In addition, a part of the surface was oxidized. Elevation of the exposure temperature to 300 /sup 0/C caused the disappearance of the D/sub 2/O(a) and/or OD(a). Consequently the O-coverage decreased, although the partially oxidized surface remained. We conclude that both Zr and V function as the active sites for the decomposition of D/sub 2/O(a) and/or OD(a). However, the Zr sites work more actively for the decomposition reaction than the V sites do. Consequently, these Zr sites determine the absorption rate.

  4. Theoretical analysis of oxygen diffusion at startup in an alkali metal heat pipe with gettered alloy walls

    NASA Technical Reports Server (NTRS)

    Tower, L. K.

    1973-01-01

    The diffusion of oxygen into, or out of, a gettered alloy exposed to oxygenated alkali liquid metal coolant, a situation arising in some high temperature heat transfer systems, was analyzed. The relation between the diffusion process and the thermochemistry of oxygen in the alloy and in the alkali metal was developed by making several simplifying assumptions. The treatment is therefore theoretical in nature. However, a practical example pertaining to the startup of a heat pipe with walls of T-111, a tantalum alloy, and lithium working fluid illustrates the use of the figures contained in the analysis.

  5. Absorption and desorption of hydrogen, deuterium, and tritium for Zr--V--Fe getter

    SciTech Connect

    Ichimura, K.; Inoue, N.; Watanabe, K.; Takeuchi, T.

    1984-07-01

    Nonevaporable getters have wide applicability for developing the tritium handling techniques for thermonuclear fusion devices. From this viewpoint, mechanisms of the absorption and desorption of hydrogen isotopes and the isotope effects were investigated for a Zr--V--Fe alloy (St-707) by means of the mass analyzed thermal desorption spectroscopy. It was observed that the absorption rate was proportional to the first power of the pressure, indicating that the rate limiting step is the dissociative adsorption of hydrogen isotopes on the surface. The activation energy was very small, in the order of magnitude of a few tens of calories per mole in a temperature range from -196 to 200 /sup 0/C. The desorption rate was proportional to the square of the amount of absorption, indicating that the rate limiting step is the associative desorption reaction of hydrogen atoms or ions diffused to the surface from the bulk. The rate constants for hydrogen and deuterium were determined as k/sub d/(H/sub 2/) = (5.3/sup +2.6//sub -1.7/)exp(-(28.0 +- 0.7) x 10/sup 3//RT) and k/sub d/(D/sub 2/) = (5.0/sup +2.7//sub -1.7/)exp(-(28.6 +- 0.8) x 10/sup 3//RT) in (1/Pa 1 s), respectively, where R is in (cal/mol deg). With regard to tritium, the rate constant was evaluated as k/sub d/(T/sub 2/) = (5.0/sup +20//sub -4.0/)exp(-(29.3 +- 3) x 10/sup 3//RT), however, the frequency factor will have to be corrected by knowing the relative sensitivity factor of the mass spectrometer for tritium (T/sub 2/).

  6. Gettering effects in Si{sub x}Ge{sub 1-x} single crystalline wafers

    SciTech Connect

    Wollweber, J.; Schulz, D.; Schroeder, W.

    1995-08-01

    The new interest in single crystal growth of SiGe solid solutions is caused by the development of advanced electronics. The SiGe alloys are mostly used in the form of Si/Si{sub x}Ge{sub 1-x} epitaxial layers in heterostructures, the perfect bulk crystals are required to study fundamental properties. Furthermore, Si{sub x}Ge{sub 1-x} crystals can be used as a substrate material instead of Silicon in order to avoid the buffer layers between the Silicon substrate and strained Si{sub x}Ge{sub 1-x}. Monocrystalline SiGe alloys may be a potential candidate as a base material for infrared solar cells too because of an enhanced IR-sensitivity. In this paper we report a new approach to the growth of Si{sub x}Ge{sub 1-x} single crystals (up to 2{double_prime} in diameter) using the crucible free rf-heated float zone technique as well as the Czochralski-technique for solar cells. The goal is to produce solar cells with an increased photo current in comparison to Silicon cells. based on the lower bandgap of the alloyed crystal. In order to be able to use the Si cells technology (a matter still pending to be proven), low contents of Ge are intended, desirably in the range of about x=0.2. It is worth to mention, that in the conventional Silicon cell processes which give efficiencies up to 18-19%, this efficiency is not limited by the bulk base recombination in the lifetime is above 200 {mu}s there. We can conclude, that there is no basic limitation did prevents Si{sub x}Ge{sub 1-x} wafers to present high lifetimes, above 200{mu}s, at least if the Ge content is below 5%. We can also conclude that the phosphorous gettering from a POCl{sub 3} source, used in silicon, can be successfully used to enhance lifetimes in Si{sub x}Ge{sub 1-x}, at least for the Ge concentration used here.

  7. High-Q Wafer Level Package Based on Modified Tri-Layer Anodic Bonding and High Performance Getter and Its Evaluation for Micro Resonant Pressure Sensor

    PubMed Central

    Wang, Liying; Du, Xiaohui; Wang, Lingyun; Xu, Zhanhao; Zhang, Chenying; Gu, Dandan

    2017-01-01

    In order to achieve and maintain a high quality factor (high-Q) for the micro resonant pressure sensor, this paper presents a new wafer level package by adopting cross-layer anodic bonding technique of the glass/silicon/silica (GSS) stackable structure and integrated Ti getter. A double-layer structure similar to a silicon-on-insulator (SOI) wafer is formed after the resonant layer and the pressure-sensitive layer are bonded by silicon direct bonding (SDB). In order to form good bonding quality between the pressure-sensitive layer and the glass cap layer, the cross-layer anodic bonding technique is proposed for vacuum package by sputtering Aluminum (Al) on the combination wafer of the pressure-sensitive layer and the resonant layer to achieve electrical interconnection. The model and the bonding effect of this technique are discussed. In addition, in order to enhance the performance of titanium (Ti) getter, the prepared and activation parameters of Ti getter under different sputtering conditions are optimized and discussed. Based on the optimized results, the Ti getter (thickness of 300 nm to 500 nm) is also deposited on the inside of the glass groove by magnetron sputtering to maintain stable quality factor (Q). The Q test of the built testing system shows that the number of resonators with a Q value of more than 10,000 accounts for more than 73% of the total. With an interval of 1.5 years, the Q value of the samples remains almost constant. It proves the proposed cross-layer anodic bonding and getter technique can realize high-Q resonant structure for long-term stable operation. PMID:28300752

  8. Impact of preparation conditions on the magnetocaloric properties of Gd thin films

    NASA Astrophysics Data System (ADS)

    Kirby, H. F.; Belyea, D. D.; Willman, J. T.; Hendryx, C. J.; Miller, C. W.

    2012-02-01

    The impact of the deposition temperature and gettering were investigated on Ta(5nm)/Gd(30nm)/Ta(5nm) thin films' magneto caloric(MCE) properties. The samples were grown by magnetron at temperatures up to 600 C, with and without gettering. Structure of the samples was investigated by X-ray diffraction and ray reflectivity. The isothermal magnetization of the samples was above and below the Curie temperature of the Gd. The entropy change associated with the second order phasewas calculated from M(H,T) using the thermodynamic Maxwell. Increasing the deposition temperature generally improves entropy peak (magnitude, FWHM, and temperature of the peak), but leads to significant oxidation. The ungettered sample grown at00 C was purely GdO (111). Gettering the chamber by sputtering Tathe walls of the chamber for 30 minutes prior to deposition this oxidation issue, and increased the relative cooling power RCP) of films grown at elevated temperatures. The RCP values of the sample set were increased by as much as 42% over ungettered. Supported by AFOSR and NSF.

  9. Update to SAND2007-0095, SAND2007-1789P, and SAND2007-7165P: 18-Month 70°C Aging Study of HiTop Hydrogen Getter for WSRC

    SciTech Connect

    Buffleben, George M.; Nissen, April; Shepodd, Timothy J.

    2008-05-01

    Hydrogen getters were tested for use in storage of plutonium-bearing materials in accordance with DOE's Criteria for Interim Safe Storage of Plutonium Bearing Materials. The original studies, documented in Sandia Report SAND2007-0095, included HiTop getter material aged for 3 months at 70°C. This material was aged for an additional 3 months for a total of 6 months at 70°C, and the performance of the getter was evaluated again and documented in Sandia Report SAND2007-1789P. This material was then aged for an additional 7 months for a total of 13 months at 70°C, and the performance of the getter under recombination and gettering conditions was evaluated. A sample of the 13 months aged getter was exposed to radiation at SRNL, and the performance of this sample was also evaluated. The results of the 13 months study is reported in SAND2007-7165P. The HiTop material was aged for an additional 5 months for a total of 18 months. This material was split into two samples with the second sample being exposed to radiation at SRNL. The performance of the 18 month aged HiTop material is covered in this report. The 18-month aged material showed similar performance under gettering conditions to the previously aged material: the recombination rate is well above the required rate of 45 std. cc H2/h, and the gettering reaction occurs in the absence of oxygen at a slower rate. Both pressure drop measurements and 1H NMR analyses support these conclusions. 1H NMR analyses show extremely minor changes in the 18-month aged material, which can be possibly attributed to slight decomposition of the HiTop material or absorption of contaminants during the aging process.

  10. Growth and Doping of Al(x)Ga(1-x)N Films by Electron Cyclotron Resonance Assisted Molecular Beam

    DTIC Science & Technology

    1994-08-31

    r 1u! silv of fa in ul:ts miicroijaph of in upper region oft a domain showinL Itn to localized re,-ions of ,x urtzite strucuure (i-rkedj thle various...99.995% purity) was purified to >99.99999% A. Film Growth by gettering with a Zr/Fe-based alloy . The nitrogen flow rate for all films grown in this...ness. For high-temperature experiments the samples were 4 placed on top of a copper finger of an electrical heater, which 10 Epitaxial enabled us to

  11. Yucca Mountain Project Getter Program Results (Year 1) I-I29 and Other Anions of Concern

    SciTech Connect

    J.L. Krumhansl; J.D. Pless; J.B. Chwirka; K.C. Holt

    2006-07-17

    Although high level nuclear wastes (HLW) contain a daunting array of radioisotopes, only a restricted number are long-lived enough to be problematic, and of these many are either effectively insoluble or are likely to be scavenged from solution by minerals indigenous to all aquifers. Those few constituents likely to travel significant distances through aquifers either form colloids (and travel as particulates) or anions--which are not sorbed onto the predominantly negatively charged mineral surfaces. Iodine ({sup 129}I) is one such constituent and may travel as either iodide (I{sup -}) or iodate (IO{sub 3}{sup -}) depending on whether conditions are mildly reducing or oxidizing. Conventionally, {sup 99}Tc (traveling as TcO{sub 4}{sup 0}) is regarded as being of greater concern since it is both more abundant and has a shorter half life (e.g., has a higher specific activity). However, it is unclear whether TcO{sub 4}{sup -} will ever actually form in the mildly reducing environments thought likely within degrading HLW canisters. Instead, technetium may remain reduced as highly insoluble Tc(lV), in which case {sup 129}I might become a significant risk driver in performance assessment (PA) calculations. In the 2004-2005 time frame the US Department of Energy (DOE)--Office of Civilian Radioactive Waste Management (OCRUM), Office of Science and Technology International (S&T) funded a program to identify ''getters'' for possible placement in the invert beneath HLW packages in the repository being planned by the Yucca Mountain Project (YMP). This document reports on progress made during the first (and only) year of this activity. The problem is not a new one and the project did not proceed in a complete vacuum of information. Potential leads came from past studies directed at developing anion getters for a near surface low-level waste facility at Hanford, which suggested that both copper-containing compounds and hydrotalcite-group minerals might be promising. Later work

  12. OPERATION OF A TRITIUM GLOVEBOX CLEAN-UP SYSTEM USING ZIRCONIUM MANGANESE IRON AND ZIRCONIUM TWO IRON METAL GETTERS

    SciTech Connect

    E. LARSON; K. COOK

    2000-08-01

    A metal hydride-based tritium clean-up system has been successfully operated for more than four years on an 11 m{sup 3} helium/nitrogen glovebox which was used for handling metal tritide powders. The clean-up system consists of two beds: (1) a Zr-Mn-Fe (in a 10% by weight Al binder, SAES ST909) bed operating at 675 C followed by (2) a Zr{sub 2}Fe (SAES ST198) bed operating at 250 C. The Zr-Mn-Fe bed serves to condition the gas stream by cracking hydrogenous impurities (such as H{sub 2}O and hydrocarbons) and absorbing oxygen and carbon. The Zr{sub 2}Fe bed absorbs the hydrogen isotopes from the flowing stream by forming a solid hydride compound. These beds contain 3 kilograms of Zr{sub 2}Fe and have been loaded routinely with 230-250 STP liters of hydrogen isotopes in earlier trials. The Zr-Mn-Fe alloy exhibits an anomaly during activation, namely an exotherm upon initial exposure to nitrogen. The purpose of this work is to better understand this reaction. Nitrogen absorption studies were done in order to quantify the nitrogen taken up by the getter and to characterize the reaction kinetics. In addition, ST909 phases before and after the reaction were studied with x-ray diffraction.

  13. Analysis of copper-rich precipitates in silicon: chemical state,gettering, and impact on multicrystalline silicon solar cellmaterial

    SciTech Connect

    Buonassisi, Tonio; Marcus, Matthew A.; Istratov, Andrei A.; Heuer, Matthias; Ciszek, Theodore F.; Lai, Barry; Cai, Zhonghou; Weber,Eicke R.

    2004-11-08

    In this study, synchrotron-based x-ray absorption microspectroscopy (mu-XAS) is applied to identifying the chemical states of copper-rich clusters within a variety of silicon materials, including as-grown cast multicrystalline silicon solar cell material with high oxygen concentration and other silicon materials with varying degrees of oxygen concentration and copper contamination pathways. In all samples, copper silicide (Cu3Si) is the only phase of copper identified. It is noted from thermodynamic considerations that unlike certain metal species, copper tends to form a silicide and not an oxidized compound because of the strong silicon-oxygen bonding energy; consequently the likelihood of encountering an oxidized copper particle in silicon is small, in agreement with experimental data. In light of these results, the effectiveness of aluminum gettering for the removal of copper from bulk silicon is quantified via x-ray fluorescence microscopy (mu-XRF),and a segregation coefficient is determined from experimental data to beat least (1-2)'103. Additionally, mu-XAS data directly demonstrates that the segregation mechanism of Cu in Al is the higher solubility of Cu in the liquid phase. In light of these results, possible limitations for the complete removal of Cu from bulk mc-Si are discussed.

  14. Analysis of copper-rich precipitates in silicon: Chemical state, gettering, and impact on multicrystalline silicon solar cell material

    NASA Astrophysics Data System (ADS)

    Buonassisi, Tonio; Marcus, Matthew A.; Istratov, Andrei A.; Heuer, Matthias; Ciszek, Theodore F.; Lai, Barry; Cai, Zhonghou; Weber, Eicke R.

    2005-03-01

    In this study, synchrotron-based x-ray absorption microspectroscopy (μ-XAS) is applied to identify the chemical states of copper-rich clusters within a variety of silicon materials, including as-grown cast multicrystalline silicon solar cell material with high oxygen concentration and other silicon materials with varying degrees of oxygen concentration and copper contamination pathways. In all samples, copper silicide (Cu3Si) is the only phase of copper identified. It is noted from thermodynamic considerations that unlike certain metal species, copper tends to form a silicide and not an oxidized compound because of the strong silicon-oxygen bonding energy; consequently the likelihood of encountering an oxidized copper particle in silicon is small, in agreement with experimental data. In light of these results, the effectiveness of aluminum gettering for the removal of copper from bulk silicon is quantified via x-ray fluorescence microscopy, and a segregation coefficient is determined from experimental data to be at least (1-2)×103. Additionally, μ-XAS data directly demonstrate that the segregation mechanism of Cu in Al is the higher solubility of Cu in the liquid phase. In light of these results, possible limitations for the complete removal of Cu from bulk mc-Si are discussed.

  15. Substrate effect on the room-temperature ferromagnetism in un-doped ZnO films

    NASA Astrophysics Data System (ADS)

    Zhan, Peng; Wang, Weipeng; Xie, Zheng; Li, Zhengcao; Zhang, Zhengjun; Zhang, Peng; Wang, Baoyi; Cao, Xingzhong

    2012-07-01

    Room-temperature ferromagnetism was achieved in un-doped ZnO films on silicon and quartz substrates. Photoluminescence measurement and positron annihilation analysis suggested that the ferromagnetism was originated from singly occupied oxygen vacancies (roughly estimated as ˜0.55 μB/vacancy), created in ZnO films by annealing in argon. The saturated magnetization of ZnO films was enhanced from ˜0.44 emu/g (on quartz) to ˜1.18 emu/g (on silicon) after annealing at 600 °C, as silicon acted as oxygen getter and created more oxygen vacancies in ZnO films. This study clarified the origin of ferromagnetism in un-doped ZnO and provides an idea to enhance the ferromagnetism.

  16. Increasing minority carrier lifetime in as-grown multicrystalline silicon by low temperature internal gettering

    NASA Astrophysics Data System (ADS)

    Al-Amin, M.; Murphy, J. D.

    2016-06-01

    We report a systematic study into the effects of long low temperature (≤500 °C) annealing on the lifetime and interstitial iron distributions in as-grown multicrystalline silicon (mc-Si) from different ingot height positions. Samples are characterised in terms of dislocation density, and lifetime and interstitial iron concentration measurements are made at every stage using a temporary room temperature iodine-ethanol surface passivation scheme. Our measurement procedure allows these properties to be monitored during processing in a pseudo in situ way. Sufficient annealing at 300 °C and 400 °C increases lifetime in all cases studied, and annealing at 500 °C was only found to improve relatively poor wafers from the top and bottom of the block. We demonstrate that lifetime in poor as-grown wafers can be improved substantially by a low cost process in the absence of any bulk passivation which might result from a dielectric surface film. Substantial improvements are found in bottom wafers, for which annealing at 400 °C for 35 h increases lifetime from 5.5 μs to 38.7 μs. The lifetime of top wafers is improved from 12.1 μs to 23.8 μs under the same conditions. A correlation between interstitial iron concentration reduction and lifetime improvement is found in these cases. Surprisingly, although the interstitial iron concentration exceeds the expected solubility values, low temperature annealing seems to result in an initial increase in interstitial iron concentration, and any subsequent decay is a complex process driven not only by diffusion of interstitial iron.

  17. Surface segregation as a means of gettering Cu in liquid-phase-epitaxy silicon thin layers grown from Al-Cu-Si solutions

    SciTech Connect

    Wang, T.H.; Ciszek, T.F.; Reedy, R.; Asher, S.; King, D.

    1996-05-01

    The authors demonstrate that, by using the natural surface segregation phenomenon, Cu can be gettered to the surface from the bulk of silicon layers so that its concentrations in the liquid-phase-epitaxy (LPE) layers are much lower than its solubility at the layer growth temperature and the reported 10{sup 17} cm{sup {minus}3} degradation threshold for solar-cell performance. Secondary-ion mass spectroscopy (SIMS) analysis indicates that, within a micron-deep sub-surface region, Cu accumulates even in as-grown LPE samples. Slower cooling after growth to room temperature enhances this Cu enrichment. X-ray photoelectron spectroscopy (XPS) measurement shows as much as 3.2% Cu in a surface region of about 50 {Angstrom}. More surface-sensitive, ion-scattering spectroscopy (ISS) analysis further reveals about 7% of Cu at the top surface. These results translate to an areal gettering capacity of about 1.0 x 10{sup 16} cm{sup {minus}2}, which is higher than the available total-area density of Cu in the layer and substrate (3.6 x 10{sup 15} cm{sup {minus}2} for a uniform 1.2 x 10{sup 17}cm{sup {minus}3} Cu throughout the layer and substrate with a total thickness of 300 {mu}m).

  18. Performance modeling of Deep Burn TRISO fuel using ZrC as a load-bearing layer and an oxygen getter

    NASA Astrophysics Data System (ADS)

    Wongsawaeng, Doonyapong

    2010-01-01

    The effects of design choices for the TRISO particle fuel were explored in order to determine their contribution to attaining high-burnup in Deep Burn modular helium reactor fuels containing transuranics from light water reactor spent fuel. The new design features were: (1) ZrC coating substituted for the SiC, allowing the fuel to survive higher accident temperatures; (2) pyrocarbon/SiC "alloy" substituted for the inner pyrocarbon coating to reduce layer failure and (3) pyrocarbon seal coat and thin ZrC oxygen getter coating on the kernel to eliminate CO. Fuel performance was evaluated using General Atomics Company's PISA code. The only acceptable design has a 200-μm kernel diameter coupled with at least 150-μm thick, 50% porosity buffer, a 15-μm ZrC getter over a 10-μm pyrocarbon seal coat on the kernel, an alloy inner pyrocarbon, and ZrC substituted for SiC. The code predicted that during a 1600 °C postulated accident at 70% FIMA, the ZrC failure probability is <10-4.

  19. The Effect of Gas Ion Bombardment on the Secondary Electron Yield of TiN, TiCN and TiZrV Coatings For Suppressing Collective Electron Effects in Storage Rings

    SciTech Connect

    Le Pimpec, F.; Kirby, R.E.; King, F.K.; Pivi, M.; /SLAC

    2006-01-25

    In many accelerator storage rings running positively charged beams, ionization of residual gas and secondary electron emission (SEE) in the beam pipe will give rise to an electron cloud which can cause beam blow-up or loss of the circulating beam. A preventative measure that suppresses electron cloud formation is to ensure that the vacuum wall has a low secondary emission yield (SEY). The SEY of thin films of TiN, sputter deposited Non-Evaporable Getters and a novel TiCN alloy were measured under a variety of conditions, including the effect of re-contamination from residual gas.

  20. Electromagnetic characterization of nonevaporable getter properties between 220-330 and 500-750 GHz for the Compact Linear Collider damping rings

    NASA Astrophysics Data System (ADS)

    Koukovini-Platia, E.; Rumolo, G.; Zannini, C.

    2017-01-01

    Due to its effective pumping ability, nonevaporable getter (NEG) coating is considered for the vacuum chambers of the Compact Linear Collider (CLIC) electron damping rings (EDR). The aim is to suppress fast beam ion instabilities. The electromagnetic (EM) characterization of the NEG properties up to ultra-high frequencies is required for the correct impedance modeling of the damping ring (DR) components. The properties are determined using rectangular waveguides which are coated with NEG. The method is based on a combination of complex transmission coefficient S21 measurements with a vector network analyzer (VNA) and 3D simulations using CST Microwave Studio® (CST MWS). The frequency ranges discussed in this paper are 220-330 and 500-750 GHz.

  1. Mössbauer study of the proximity gettering of cobalt atoms to He-induced nanosized voids in c-Si

    NASA Astrophysics Data System (ADS)

    Deweerd, W.; Barancira, T.; Bukshpan, S.; Demuynck, S.; Langouche, G.; Milants, K.; Moons, R.; Verheyden, J.; Pattyn, H.

    1996-06-01

    We observe a strong gettering of ion implanted 57Co to the internal surface of empty nanosized voids in c-Si, hampering normal silicide formation. The cavities are introduced by implanting He far above the solubility limits and subsequent desorption at 700 °C during 30 min. After 57Co implantation and thermal treatment, a previously unobserved Mössbauer spectrum was recorded that could be fitted consistently with two quadrupole doublets. They differ largely in binding strength and electric-field gradient Vzz and we preliminarily interpret them as an edge site (strong binding, smaller Vzz) and a surface site (loose binding, larger Vzz) at the internal surface of the faceted voids. The spectra are stable upon high-temperature annealing.

  2. Preparation of CaO as OLED getter material through control of crystal growth of CaCO{sub 3} by block copolymers in aqueous solution

    SciTech Connect

    Park, Jae-Hyung; Oh, Seong-Geun

    2009-01-08

    As the starting materials of organic light-emitting diode (OLED) getter, calcium carbonate (CaCO{sub 3}) particles with various shapes and crystal structures have been successfully prepared with additives (L64 or PEGPG), which contain blocks of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO). These CaCO{sub 3} particles were calcinated into highly crystalline calcium oxide (CaO) nanoparticles with high capacity of water adsorption up to 14.23 wt.%. The CaCO{sub 3} and CaO particles prepared at various conditions were characterized using the field emission scanning electron microscopy (FE-SEM), Fourier transform infrared microscopy (FT-IR), X-ray powder diffraction (XRD), and dynamic vapor sorption (DVS) method.

  3. Background reduction by a getter pump around the ionization volume of a Lamb-shift polarimeter and possible improvements of polarized ion sources

    SciTech Connect

    Engels, R.; Emmerich, R.; Grigoryev, K.; Paetz gen Schieck, H.; Ley, J.; Mikirtychyants, M.; Rathmann, F.; Sarkadi, J.; Seyfarth, H.; Tenckhoff, G.; Vasilyev, A.

    2005-05-15

    The Koeln-Juelich Lamb-shift polarimeter is used to measure the nuclear polarization of the hydrogen or deuterium beam produced with the atomic-beam source for the polarized target at the ANKE spectrometer at COSY-Juelich. The precision of the earlier results had been dominated by the recombination of atoms in the ionizer. Protons or deuterons from the dissociative ionization of unpolarized recombined H{sub 2} or D{sub 2} molecules had strongly contributed to the extracted ion beam. To suppress this effect, in the new ionizer a nonevaporable getter pump of about 2000 l/s H{sub 2} or D{sub 2} pumping speed surrounds the ionization volume. It reduces the extracted current of unpolarized ions, produced from the recombined molecular gas, by a factor of about 20 compared with the earlier value, which reduces the error of the polarization measurements to about 0.5%. Now the H{sub 2} or D{sub 2} molecules in the ionization volume predominantly are those which are contained in the incoming beam from the atomic beam source. This allows the measurement of the fraction of unpolarized molecules in the polarized atomic H-vector or D-vector beam. The improvement achieved is a valuable step toward the measurement of the nuclear polarization of a gas sample, extracted from the storage cell of the polarized internal gas target for the spectrometer ANKE in the COSY-Juelich storage ring with the Lamb-shift polarimeter. Furthermore, the results show that the polarization of proton or deuteron beams would be increased by the installation of such a pump around the ionization volume of atomic-beam ion sources with an electron-impact ionizer. For ECR ionizers the recombined H{sub 2} or D{sub 2} molecules would be absorbed, whereas the noble gases, used as buffer, are not pumped by the getter material.

  4. Deposition and characterization of TiZrV-Pd thin films by dc magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Wang, Jie; Zhang, Bo; Xu, Yan-Hui; Wei, Wei; Fan, Le; Pei, Xiang-Tao; Hong, Yuan-Zhi; Wang, Yong

    2015-12-01

    TiZrV film is mainly applied in the ultra-high vacuum pipes of storage rings. Thin film coatings of palladium, which are added onto the TiZrV film to increase the service life of nonevaporable getters and enhance H2 pumping speed, were deposited on the inner face of stainless steel pipes by dc magnetron sputtering using argon gas as the sputtering gas. The TiZrV-Pd film properties were investigated by atomic force microscope (AFM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and X-Ray Diffraction (XRD). The grain size of TiZrV and Pd films were about 0.42-1.3 nm and 8.5-18.25 nm respectively. It was found that the roughness of TiZrV films is small, about 2-4 nm, but for Pd film it is large, about 17-19 nm. The PP At. % of Pd in TiZrV/Pd films varied from 86.84 to 87.56 according to the XPS test results. Supported by National Natural Science Funds of China (11205155) and Fundamental Research Funds for the Central Universities (WK2310000041)

  5. Film Reviews.

    ERIC Educational Resources Information Center

    Lance, Larry M.; Atwater, Lynn

    1987-01-01

    Reviews four Human Sexuality films and videos. These are: "Personal Decisions" (Planned Parenthood Federation of America, 1985); "The Touch Film" (Sterling Production, 1986); "Rethinking Rape" (Film Distribution Center, 1985); "Not A Love Story" (National Film Board of Canada, 1981). (AEM)

  6. Influence of ceramic package internal components on the performance of vacuum sealed uncooled bolometric detectors

    NASA Astrophysics Data System (ADS)

    Paquet, Alex; Deshaies, Sébastien; Desroches, Yan; Whalin, Jeff; Topart, Patrice

    2013-03-01

    INO has developed a hermetic vacuum packaging technology for uncooled bolometric detectors based on ceramic leadless chip carriers (LCC). Cavity pressures less than 3 mTorr are obtained. Processes are performed in a state-of-the art semi-automated vacuum furnace that allows for independent activation of non-evaporable thin film getters. The getter activation temperature is limited by both the anti-reflection coated silicon or germanium window and the MEMS device built on CMOS circuits. Temperature profiles used to achieve getter activation and vacuum sealing were optimized to meet lifetime and reliability requirements of packaged devices. Internal package components were carefully selected with respect to their outgassing behavior so that a good vacuum performance was obtained. In this paper, INO's packaging process is described. The influence of various package internal components, in particular the CMOS circuits, on vacuum performance is presented. The package cavity pressure was monitored using INO's pressure microsensors and the gas composition was determined by internal vapor analysis. Lifetime was derived from accelerated testing after storage of packaged detectors at various temperatures from room temperature to 120°C. A hermeticity yield over 80% was obtained for batches of twelve devices packaged simultaneously. Packaged FPAs submitted to standard MIL-STD-810 reliability testing (vibration, shock and temperature cycling) exhibited no change in IR response. Results show that vacuum performance strongly depends on CMOS circuit chips. Detectors packaged using a thin film getter show no change in cavity pressure after storage for more than 30 days at 120°C. Moreover, INO's vacuum sealing process is such that even without a thin film getter, a base pressure of less than 10 mTorr is obtained and no pressure change is observed after 40 days at 85°C.

  7. On the breakup of a thin liquid film subject to interfacial shear

    NASA Astrophysics Data System (ADS)

    Saber, Hamed H.; El-Genk, Mohamed S.

    2004-02-01

    The breakup of a thin non-evaporating liquid film that is either flowing down or climbing on a vertical or inclined surface and subject to cocurrent or countercurrent interfacial shear (or gas flow) is investigated analytically. Analytical expressions for the dimensionless liquid film thickness, Delta_{scriptsizemin}, and wetting rate, Gamma_{scriptsizemin}, at breakup are derived based on the minimization of the total energy of a stable rivulet, formed following the film breakup. For a downflowing liquid film, increasing the cocurrent interfacial shear (or gas velocity) or decreasing the equilibrium contact angle, theta_{o}, decreases both Delta_{scriptsizemin} and Gamma _{scriptsizemin}, below their values with zero interfacial shear. Conversely, increasing the countercurrent interfacial shear or theta_{o}, increases both Delta_{scriptsizemin} and Gamma_{scriptsizemin}, above their values with zero interfacial shear. The predictions of Delta _{scriptsizemin} and Gamma _{scriptsizemin} for a climbing water film on a vertical surface are in good agreement with reported experimental data for a wide range of cocurrent gas velocities.

  8. Film Boxes.

    ERIC Educational Resources Information Center

    Osterer, Irv

    2002-01-01

    Presents an art lesson in which students created three-dimensional designs for 35mm film packages to improve graphic arts learning. Describes how the students examined and created film boxes using QuarkXPress software. (CMK)

  9. Film Reviews

    ERIC Educational Resources Information Center

    Dowling, John, Ed.

    1976-01-01

    Reviews five instructional films on: P-N junctions; crystal diodes; nuclear fusion research; Schlieren photography; and the energy crisis; including discussions of solar, nuclear, and fossil fuel energy. Also lists numerous other available films. (MLH)

  10. On Film

    ERIC Educational Resources Information Center

    Watts, Marty

    2006-01-01

    In this article, the author discusses the role of window films in enhancing indoor air quality in schools. Historically, window film has been used to reduce temperatures in buildings prone to overheating. Too much solar energy entering through windows makes occupants uncomfortable and air conditioning more costly. Film has been a simple solution…

  11. Nanocomposite films

    DOEpatents

    Mitlin, David; , Ophus, Colin; Evoy, Stephane; Radmilovic, Velimir; Mohammadi, Reza; Westra, Ken; Nelson-Fitzpatrick, Nathaniel; Lee, Zonghoon

    2010-07-20

    A thin-film composition of nanocrystal molybdenum in an amorphous metallic matrix may be formed by co-sputtering Mo with aluminum or nickel. NEMS cantilevers may be formed from the film. The films exhibit high nanoindentation hardness and a reduction in roughness and intrinsic stress, while maintaining resistivity in the metallic range.

  12. Film ispalators

    SciTech Connect

    Startsev, Aleksandr V; Stoilov, Yurii Yu

    2002-05-31

    New physical objects, ispalators based on free soap films, exhibit persistent flows of the soap solution in open and closed volumes in air with additions of gases of the C{sub 8}F{sub 18} type (p = 20 Torr) at temperature drops on the films of the order of tenths and hundredths of kelvin. The flows move continuously at a velocity of 5 - 20 cm s{sup -1}. It is found that the parts of an inclined ispalator film show anomalous behaviour upon heating: their weight increases and they move downward over the film, whereas the unheated parts of the film move upward. Continuous radial vortex flows accompanied by the formation and washing of the regions of a thin black film are observed on circular films in closed volumes upon their uniform external cooling by evaporating water for 5 - 10 hours. The rapid flows make film ispalators the efficient heat carriers, which operate at small temperature drops (tenths and hundredths of kelvin) and surpass copper in the amount of thermal energy being transferred. The outlook for the further study and applications of film ispalators for detecting thermal fields and laser radiation is discussed. (laser applications and other topics in quantum electronics)

  13. About Films.

    ERIC Educational Resources Information Center

    Christman, Robert; Krockover, Gerald H.

    1984-01-01

    Lists and briefly describes 46 college-level films. Films are arranged in the following categories: volcanism and earthquakes; plate tectonics; energy, water, and environmental concerns; petroleum and coal; astronomy; space exploration, space shuttle; paleontology; geomorphology; and mineralogy, petrology, and economic geology. (BC)

  14. Film Language.

    ERIC Educational Resources Information Center

    Hudlin, Edward W.

    1979-01-01

    The author briefly surveys some of the claims made about the presumed nature of film as language and some of the problems that arise. He considers the views of two influential schools of film criticism: the Russian formalists (Pudovkin and Eisenstein) and the British semiologist (Peter Wollen). (Author/SJL)

  15. Thin Film?

    NASA Astrophysics Data System (ADS)

    Kariper, İ. Afşin

    2014-09-01

    This study focuses on the critical surface tension of lead sulfite (PbSO3) crystalline thin film produced with chemical bath deposition on substrates (commercial glass).The PbSO3 thin films were deposited at room temperature at different deposition times. The structural properties of the films were defined and examined according to X-ray diffraction (XRD) and the XRD results such as dislocation density, average grain size, and no. of crystallites per unit area. Atomic force microscopy was used to measure the film thickness and the surface properties. The critical surface tension of the PbSO3 thin films was measured with an optical tensiometer instrument and calculated using the Zisman method. The results indicated that the critical surface tension of films changed in accordance with the average grain size and film thickness. The film thickness increased with deposition time and was inversely correlated with surface tension. The average grain size increased according to deposition time and was inversely correlated with surface tension.

  16. A Real Attention-Getter

    NASA Technical Reports Server (NTRS)

    2003-01-01

    While most parents would agree that playing videos games is the antithesis of time well spent for their children, recent advances involving NASA biofeedback technology are proving otherwise. The same techniques used to measure brain activity in NASA pilots during flight simulation exercises are now a part of a revolutionary video game system that is helping to improve overall mental awareness for Americans of all ages, including those who suffer from Attention Deficit Hyperactivity Disorder (ADHD).

  17. Getters for Reliable Hermetic Packages

    NASA Technical Reports Server (NTRS)

    Ramesham, R.

    2000-01-01

    A variety of sealed-off devices such as cathode ray tubes (CRT's) electron tubes, plasma displays, particle accelarators and colliders vacuum thermal insulation, ultra-high vacuum (UHV), extreme high vacuum (XHV) systems for semiconductor processing, X-ray tubes, lamps, field-emission displays (FEDs) flat panel displays (FPDs), some microelectromechanical systems (MEMS) and science instruments for space applications, nuclear systems require a vacuum for their successful operation.

  18. Getter materials for cracking ammonia

    DOEpatents

    Boffito, Claudio; Baker, John D.

    1999-11-02

    A method is provided for cracking ammonia to produce hydrogen. The method includes the steps of passing ammonia over an ammonia-cracking catalyst which is an alloy including (1) alloys having the general formula Zr.sub.1-x Ti.sub.x M.sub.1 M.sub.2, wherein M.sub.1 and M.sub.2 are selected independently from the group consisting of Cr, Mn, Fe, Co, and Ni, and x is between about 0.0 and about 1.0 inclusive; and between about 20% and about 50% Al by weight. In another aspect, the method of the invention is used to provide methods for operating hydrogen-fueled internal combustion engines and hydrogen fuel cells. In still another aspect, the present invention provides a hydrogen-fueled internal combustion engine and a hydrogen fuel cell including the above-described ammonia-cracking catalyst.

  19. Polymer formulations for gettering hydrogen

    DOEpatents

    Shepodd, Timothy J.; Even, Jr., William R.

    2000-01-01

    A novel method for preparing a hydrogenation composition comprising organic polymer molecules having carbon--carbon double bonds, for removing hydrogen from the atmosphere within enclosed spaces and particularly from atmospheres within enclosed spaces that contain air, water vapor, oxygen, carbon dioxide or ammonia. The organic polymers molecules containing carbon--carbon double bonds throughout their structures, preferably polybutadiene, polyisoprene and derivatives thereof, intimately mixed with an insoluble noble metal catalyst composition. High molecular weight polymers may be added to the organic polymer/catalyst mixture in order to improve their high temperature performance. The hydrogenation composition is prepared by dispersing the polymers in a suitable solvent, forming thereby a solution suspension, flash-freezing droplets of the solution in a liquid cryogen, freeze-drying the frozen droplets to remove frozen solvent incorporated in the droplets, and recovering the dried powder thus formed.

  20. Film Makers On Film Making.

    ERIC Educational Resources Information Center

    Geduld, Harry M., Ed.

    This collection includes essays by and interviews with more than 30 film-makers, both classic and contemporary, on the subjects of their major interests and procedures in making films. The directors are: Louis Lumiere, Cecil Hepworth, Edwin S. Porter, Mack Sennett, David W. Griffith, Robert Flaherty, Charles Chaplin, Eric von Stroheim, Dziga…

  1. Piezoelectric Film.

    ERIC Educational Resources Information Center

    Garrison, Steve

    1992-01-01

    Presents activities that utilize piezoelectric film to familiarize students with fundamental principles of electricity. Describes classroom projects involving chemical sensors, microbalances, microphones, switches, infrared sensors, and power generation. (MDH)

  2. Polymer films

    DOEpatents

    Granick, Steve; Sukhishvili, Svetlana A.

    2004-05-25

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  3. Polymer films

    DOEpatents

    Granick, Steve; Sukhishvili, Svetlana A.

    2008-12-30

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  4. Film Reviews

    ERIC Educational Resources Information Center

    Ladd, George T.

    1974-01-01

    Briefly describes films about the following topics: water cycles, the energy crisis, the eruption of Mt. Aetna, the hot springs of Yellowstone National Park, and methods of using pine cones to determine the ages of ancient civilizations. (MLH)

  5. Secondary electron yield measurements from thin surface coatings for NLC electron cloud reduction

    SciTech Connect

    Le Pimpec, F

    2004-05-17

    In the beam pipe of the positron damping ring of the Next Linear Collider, electrons will be created by beam interaction with the surrounding vacuum chamber wall and give rise to an electron cloud. Several solutions are possible for avoiding the electron cloud, without changing the beam bunch structure or the diameter of the vacuum chamber. Some of the currently available solutions for preventing this spurious electron load include reducing residual gas ionization by the beam, minimizing beam photon-induced electron production, and lowering the secondary electron yield (SEY) of the chamber wall. We will report on recent SEY measurements performed at SLAC on TiN coatings and TiZrV non-evaporable getter thin films.

  6. Science Fiction on Film.

    ERIC Educational Resources Information Center

    Burmester, David

    1985-01-01

    Reviews science fiction films used in a science fiction class. Discusses feature films, short science fiction films, short story adaptations, original science fiction pieces and factual science films that enrich literature. (EL)

  7. An x-ray photoemission spectroscopy investigation of thermal activation induced changes in surface composition and chemical bonds of two gettering alloys: Zr sub 2 Fe versus Zr sub 57 V sub 36 Fe sub 7

    SciTech Connect

    Sancrotti, M.; Trezzi, G. ); Manini, P. )

    1991-03-01

    We report comparative XPS ({ital h}{nu}=1253.6 eV) core level (Zr 3{ital d}; C 1{ital s}; O 1{ital s}; Fe 2{ital p}; V 2{ital p}) results from two relevant gettering alloys: Zr{sub 2}Fe and Zr{sub 57}V{sub 36}Fe{sub 7}. The samples were studied as-received (after in-air fracturing of bulk ingots) and after different annealing treatments (up to 700 {degree}C) performed in ultrahigh vacuum. With increasing temperature both alloys show a progressive dissolution of Zr oxides, an increase in the metallic character of the surface, the gradual loss of C based adsorbates, and a progressive increase in the surface Zr content and at the expense of the C concentration. At temperatures in the range 300--550 {degree}C a fraction of the C atoms form metallic carbides. OH-based groups are depleted from the surface at low temperatures (200 {degree}C), resulting in a sizable decrease of the near surface O content, while a nearly constant O concentration is found at intermediate and high temperatures. Only minor changes are observed for the near surface concentrations of Fe in Zr{sub 2}Fe and Fe and V in Zr{sub 57}V{sub 36}Fe{sub 7} as a function of temperature. The two alloys show strong differences in the activation kinetics of these changes, with surface metallization being initiated at lower temperatures and proceeding faster in Zr{sub 57}V{sub 36}Fe{sub 7}. Metallic carbides are found to almost completely dissolve in Zr{sub 57}V{sub 36}Fe{sub 7} at 600--700 {degree}C, while they are retained even at high temperatures in Zr{sub 2}Fe. The kinetic differences determined via XPS are consistent with the differences in gettering behavior of Zr{sub 2}Fe and Zr{sub 57}V{sub 36}Fe{sub 7}.

  8. Film Credits

    ERIC Educational Resources Information Center

    Borja, Rhea R.

    2006-01-01

    With the advent of easy-to-use digital technology, schools are responding to the interests of their media-savvy students by offering more courses in filmmaking. In this article, the author features different films produced by students. Among other things, she discusses the students' growing interest in filmmaking.

  9. Black Films and Film-Makers.

    ERIC Educational Resources Information Center

    Patterson, Lindsay, Ed.

    The development of black films and the attitudes of the film industry toward black films and black actors are some of the topics examined in this anthology of essays. Section 1, "Nigger to Supernigger," contains such articles as "The Death of Rastus: Negroes in American Films" by Thomas R. Cripps and "Folk Values in a New Medium" by Alain Locke…

  10. Film and History.

    ERIC Educational Resources Information Center

    Schaber, Robin L.

    2002-01-01

    Provides an annotated bibliography of Web sites that focus on using film to teach history. Includes Web sites in five areas: (1) film and education; (2) history of cinema; (3) film and history resources; (4) film and women; and (5) film organizations. (CMK)

  11. War. Peace. Film Guide.

    ERIC Educational Resources Information Center

    Dougall, Lucy

    The revised and expanded film guide designed for educators includes annotations of over 200 films, plus a large number of program resources for intelligent film use. Selected from over five hundred films previewed from 1969, up-to-date films were chosen that would help interpret the causes of war, increase awareness of the dehumanizing effects of…

  12. Filming The Man Hunters

    ERIC Educational Resources Information Center

    Hockings, Paul

    1976-01-01

    "The Man Hunters" is a film about paleoanthropology. This article is a personal account of how the film was put together using anthropological knowledge and numerous anthropologists and how the film was received by the American public. (Author)

  13. Ferroelectric ultrathin perovskite films

    DOEpatents

    Rappe, Andrew M; Kolpak, Alexie Michelle

    2013-12-10

    Disclosed herein are perovskite ferroelectric thin-film. Also disclosed are methods of controlling the properties of ferroelectric thin films. These films can be used in a variety materials and devices, such as catalysts and storage media, respectively.

  14. Film Presentation Techniques.

    ERIC Educational Resources Information Center

    Monod, Pierre

    1976-01-01

    This article discusses three types of films and their use in the second language classroom. The description film is objective and static, and elicits adjectives and adverbs. This kind of film should be presented three times, each time followed by a different set of learning exercises. The culture film - characterized by descriptions, scenes from…

  15. Films on Oceanography.

    ERIC Educational Resources Information Center

    Cuzon du Rest, R. P.

    This film list compiled by the U.S. Naval Oceanographic Office is separated into six categories: general oceanography, biology, chemistry, engineering, geology, and physics. An index of films is followed by addresses of Naval Districts and lists of distribution centers. Each film listed is described as to content, running time, type of film,…

  16. Thin film interference of colloidal thin films.

    PubMed

    Cong, Hailin; Cao, Weixiao

    2004-09-14

    A stairlike colloidal crystal thin film composed of poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) monodispersed colloids was fabricated on an inclined silicon substrate. Different bright colors were observed on the various parts of the film with different layers as white light irradiated perpendicularly on it. The relationship between the colors and layers of the film was investigated and discussed according to the principle of thin film interference. On the basis of the phenomenon of thin film interference, a one-layer colloidal film having uniform color was researched and it would display diverse colors before and after swollen by styrene (St). A circular stairlike colloidal film was achieved to mimic the colors of the peacock tail feather.

  17. Carbon thin film thermometry

    NASA Technical Reports Server (NTRS)

    Collier, R. S.; Sparks, L. L.; Strobridge, T. R.

    1973-01-01

    The work concerning carbon thin film thermometry is reported. Optimum film deposition parameters were sought on an empirical basis for maximum stability of the films. One hundred films were fabricated for use at the Marshall Space Flight Center; 10 of these films were given a precise quasi-continuous calibration of temperature vs. resistance with 22 intervals between 5 and 80 K using primary platinum and germanium thermometers. Sensitivity curves were established and the remaining 90 films were given a three point calibration and fitted to the established sensitivity curves. Hydrogen gas-liquid discrimination set points are given for each film.

  18. Durable solar mirror films

    DOEpatents

    O'Neill, Mark B.; Henderson, Andrew J.; Hebrink, Timothy J.; Katare, Rajesh K.; Jing, Naiyong; North, Diane; Peterson, Eric M.

    2017-02-14

    The present disclosure generally relates to durable solar mirror films, methods of making durable solar mirror films, and constructions including durable solar mirror films. In one embodiment, the present disclosure relates to a solar mirror film comprising: a multilayer optical film layer including having a coefficient of hygroscopic expansion of less than about 30 ppm per percent relative humidity; and a reflective layer having a coefficient of hygroscopic expansion.

  19. The Educational Film Industry

    ERIC Educational Resources Information Center

    Tortora, Vincent R.; Schillaci, Peter

    1975-01-01

    Increased dialog is needed among educational film producers, distributors, and consumers in order to be sure that what is being produced meets educators' needs and also to help solve the financial problems of the film industry. (LS)

  20. Microstructure of Thin Films

    DTIC Science & Technology

    1990-02-07

    optical properties ." (Final text in preparation). John Lehan, "Microstructural analysis of thin films by Rutherford Backscattering...correlation of optical properties and micro- Ion assisted deposition (IAD) is known to produce structure of IAD thin films with ion beam parameters thin films ...1.5-eV interband absorption. P (eV) R (%) P (, -V) R %) Optical properties of metal thin films in the spectral 0 98.3 0 88.8 range of

  1. Non-Evaporative Cooling via Inelastic Collisions in an Optical Trap

    DTIC Science & Technology

    2013-02-28

    first-order Zeeman effect rather than second-order Zeeman effect for cooling, resulting in easier experimental apparatus design. The use of two atoms...the second-order Zeeman effect . This energy is supplied by the atoms’ kinetic energy in the collision. After the spin-exchange collisions have been...population, but have reduced kinetic energy. In effect , the spin-exchange collisions transfer kinetic energy to Zeeman energy that is subsequently

  2. Formation, release and assembly of a non-evaporative photocurable liquid through micromolding and inkjet printing

    NASA Astrophysics Data System (ADS)

    Chen, Chin-Tai; Huang, Hsiang-Pi

    2013-09-01

    This paper presents a hybrid method combining micromolding and inkjet printing for the formation of microparts at milli- to micrometer scales. Two-dimensional footprints of versatile shapes such as rotors and characters are first realized by micromolding. Then microdroplets are inkjet-printed into the micro-cavities of the micromolds, yielding three-dimensional formations of liquid with remarkable heights. Printed liquid of NOA 89 is photocurable for ultraviolet (UV) light, featuring 100% solids without the evaporation involved in solidification. After UV curing the liquid formations created solid and coherent textures with voids found through experiments. The shapes and morphologies of the formed parts are found to be uniform and smooth while using hydrophobic PDMS (polydimethysiloxane) as the material of the micromolds. Moreover, release of microparts from those molds is achievable by simple bending due to the elastomer property of PDMS. The molds and parts remain intact after separation. The assembly of the released parts of the rotors into the micro-channels of a PDMS fluidic chip is also demonstrated. Hence, the current method provides access to a cost-efficient manufacturing process of microparts with little waste as the micromolds can be reused via inkjet printing.

  3. Film as Film; Understanding and Judging Movies.

    ERIC Educational Resources Information Center

    Perkins, V. F.

    The criteria for judging movies which are presented here are based on the belief that film criticism becomes rational, if not "objective", when it displays and inspects the nature of its evidence and the bases of its arguments. The author dissents from the view of early film theorists that montage is the essence of cinema, and that cinema is to be…

  4. Getting into Film.

    ERIC Educational Resources Information Center

    London, Mel

    This book describes the various aspects of the film industry and the many jobs related to filmmaking, stressing that no "formula" exists for finding a successful career in the film industry. Chapters provide information on production, writing for film, cinematography, editing, music, sound, animation and graphics, acting and modeling, the "unsung…

  5. Australian Film Studies.

    ERIC Educational Resources Information Center

    Breen, Myles P.

    Although Australia had a vigorous film industry in the silent film era, it was stifled in the 1930s when United States and British interests bought up the Australian distribution channels and closed down the indigenous industry. However, the industry and film study have undergone a renaissance since the advent of the Labor government in 1972,…

  6. The Language of Film.

    ERIC Educational Resources Information Center

    Whitaker, Rod

    This book, designed for the film maker, critic, and serious filmgoer, explores elements of filmic expression from the creative and perceptual points of view. Chapters (1) trace the linguistic and mechanical development of film, (2) discuss the contributions of image and sound to film content, (3) suggest the contributions of editing and montage,…

  7. Playing With Film.

    ERIC Educational Resources Information Center

    Gaffney, Maureen, Ed.

    1980-01-01

    Designed for media specialists and educators, this issue includes five articles on innovative museum film programs. The first article describes a successful film program conducted at the Staten Island Children's Museum. The second article describes inventive children's programs at the Delaware Museum of Art. The programs use films and activities…

  8. 99 Films on Drugs.

    ERIC Educational Resources Information Center

    Weber, David O., Ed.

    This catalog describes and evaluates 16-millimeter films about various aspects of drug use. Among the subjects covered by the 99 films are the composition and effects of different drugs, reasons why people use drugs, life in the drug culture, the problem of law enforcement, and various means of dealing with drug users. Each film is synopsized. Two…

  9. Focus on Shakespearean Films.

    ERIC Educational Resources Information Center

    Eckert, Charles W., Ed.

    This is an anthology of reviews and critical pieces of the significant and available Shakespearean films made between 1935 and 1966. Included are three general essays on Shakespearean film by Ian Johnson, Henri Lemaitre, and Geoffrey Reeves. The specific films and their reviewers are: A Midsummer's Night Dream (1935) Allardyce Nicoll and Richard…

  10. Health Careers Film Guide.

    ERIC Educational Resources Information Center

    National Institutes of Health (DHEW), Bethesda, MD. Bureau of Health Manpower Education.

    This document, which represents a survey of the entire health career film field, was designed to provide information for people interested in a health career. The guide indicates that a major criteria for film selection was recency; however, some older films that give a fairly accurate image of a profession were included, with some emphasis given…

  11. Thick Film Interference.

    ERIC Educational Resources Information Center

    Trefil, James

    1983-01-01

    Discusses why interference effects cannot be seen with a thick film, starting with a review of the origin of interference patterns in thin films. Considers properties of materials in films, properties of the light source, and the nature of light. (JN)

  12. Marine Science Film Catalogue.

    ERIC Educational Resources Information Center

    Chapman, Frank L.

    Forty-eight motion picture films and filmstrips in the field of marine science are catalogued in this booklet. Following the alphabetical index, one page is devoted to each film indicating its type, producer, recommended grade level, running time, and presence of color and/or sound. A summary of film content, possible uses, and outstanding…

  13. Film Program Notes from the Current Holdings of the Anthology Film Archives; Outlines of 41 Films.

    ERIC Educational Resources Information Center

    Anthology Film Archives, New York, NY.

    This collection of film program notes includes mixed commentary on some of the films held in the Anthology Film Archives (a film and book library in New York City). Some of the films are described by synopsis of the episodes and others by translation into English of the foreign language subtitles. However, each film noted is identified by full…

  14. Electrically Conductive Polyimide Films

    NASA Technical Reports Server (NTRS)

    St. Clair, Anne K.; Ezzel, Stephen A.; Taylor, Larry T.; Boston, Harold G.

    1993-01-01

    Semiconducting surfaces of SnO2 formed by curing polyamic acids containing tin complexes. Polyimide films made semiconductive via incorporation of semiconductive surface layers of SnO2. If SnO2-surfaced polyimide film used as free-standing film, then semiconductive layer protected by top coat of polyimide, deposited as film from solution directly onto SnO2. Resultant films flexible and resistant to both weather and high temperature. Used on aircraft to provide resistance to lightning strikes, and in microelectronics and flexible circuitry.

  15. Pyrolyzed thin film carbon

    NASA Technical Reports Server (NTRS)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

    2010-01-01

    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  16. Chronicles of foam films.

    PubMed

    Gochev, G; Platikanov, D; Miller, R

    2016-07-01

    The history of the scientific research on foam films, traditionally known as soap films, dates back to as early as the late 17th century when Boyle and Hooke paid special attention to the colours of soap bubbles. Their inspiration was transferred to Newton, who began systematic study of the science of foam films. Over the next centuries, a number of scientists dealt with the open questions of the drainage, stability and thickness of foam films. The significant contributions of Plateau and Gibbs in the middle/late 19th century are particularly recognized. After the "colours" method of Newton, Reinold and Rücker as well as Johhonnot developed optical methods for measuring the thickness of the thinner "non-colour" films (first order black) that are still in use today. At the beginning of the 20th century, various aspects of the foam film science were elucidated by the works of Dewar and Perrin and later by Mysels. Undoubtedly, the introduction of the disjoining pressure by Derjaguin and the manifestation of the DLVO theory in describing the film stability are considered as milestones in the theoretical development of foam films. The study of foam films gained momentum with the introduction of the microscopic foam film methodology by Scheludko and Exerowa, which is widely used today. This historical perspective serves as a guide through the chronological development of knowledge on foam films achieved over several centuries.

  17. Ceramic Composite Thin Films

    NASA Technical Reports Server (NTRS)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  18. "Silent" Films Revisited: Captioned Films for the Deaf.

    ERIC Educational Resources Information Center

    Kovalik, Gail L.

    1992-01-01

    Provides a history of the Captioned Films/Videos for the Deaf program and describes the kinds of films and videos available, including feature films and educational materials. Silent films are discussed; captioning processes are described; implications for librarians are discussed; and regional depository libraries for captioned films for the deaf…

  19. Self regulating formulations for safe hydrogen gettering

    DOEpatents

    Shepodd, Timothy Jon

    2004-03-16

    A method and composition are disclosed for preventing uncontrolled exothermic reaction in the presence of a catalyst. A catalyst deployed as a finely divided powder which is attached to the surface of a low melting point wax or wax-like material which is utilized as a carrier for the catalyst. During operation should the catalyst overheat due to uncontrolled conditions brought about by a run-away reaction the heat of reaction melts the low melting point wax which would itself wet the surface of the catalyst and prevent further catalysis.

  20. Self regulating formulations for safe hydrogen gettering

    DOEpatents

    Shepodd, Timothy Jon

    2002-01-01

    A method and composition are disclosed for preventing uncontrolled exothermic reaction in the presence of a catalyst. A catalyst deployed as a finely divided powder which is attached to the surface of a low melting point wax or wax-like material which is utilized as a carrier for the catalyst. During operation should the catalyst overheat due to uncontrolled conditions brought about by a run-away reaction the heat of reaction melts the low melting point wax which would itself wet the surface of the catalyst and prevent further catalysis.

  1. Coating of plasma polymerized film

    NASA Technical Reports Server (NTRS)

    Morita, S.; Ishibashi, S.

    1980-01-01

    Plasma polymerized thin film coating and the use of other coatings is suggested for passivation film, thin film used for conducting light, and solid body lubrication film of dielectrics of ultra insulators for electrical conduction, electron accessories, etc. The special features of flow discharge development and the polymerized film growth mechanism are discussed.

  2. Film Music. Factfile No. 8.

    ERIC Educational Resources Information Center

    Elsas, Diana, Ed.; And Others

    Organizations listed here with descriptive information include film music clubs and music guilds and associations. These are followed by a representative list of schools offering film music and/or film sound courses. Sources are listed for soundtrack recordings, sound effects/production music, films on film music, and oral history programs. The…

  3. Documentary Elements in Early Films.

    ERIC Educational Resources Information Center

    Sanderson, Richard A.

    Focusing on documentary elements, this study examines the film content and film techniques of 681 motion pictures produced in the United States prior to 1904. Analysis of films by type, subject matter, and trends in subject matter shows that one-third of the early films are documentary in type and three-fourths of the films use subject matter of a…

  4. Renaissance of the Film.

    ERIC Educational Resources Information Center

    Bellone, Julius, Ed.

    The post-World War II period was one of the liveliest in the history of the cinema. This is a collection of 33 critical articles on some of the best films of the perd. Most of the essays explicate the themes and symbols of the films. The essays deal with these films: "The Apu Trilogy,""L'Avventura,""Balthazar,""Blow-Up,""Bonnie and Clyde," Citizen…

  5. Clinical careers film.

    PubMed

    2015-09-01

    Those interested in developing clinical academic careers might be interested in a short animated film by Health Education England (HEE) and the National Institute for Health Research. The three-minute film, a frame from which is shown below, describes the sort of opportunities that are on offer to all professionals as part of the HEE's clinical academic careers framework. You can view the film on YouTube at tinyurl.com/pelb95c.

  6. Daylight Redirecting Window Film

    DTIC Science & Technology

    2013-12-01

    EW-201014) Daylight Redirecting Window Film December 2013 This document has been cleared for public release; Distribution...DEC 2013 2. REPORT TYPE 3. DATES COVERED 00-00-2013 to 00-00-2013 4. TITLE AND SUBTITLE Daylight Redirecting Window Film 5a. CONTRACT NUMBER...CCE cost of conserved energy DoD Department of Defense DRF daylight redirecting film EPA U.S. Environmental Protection Agency ESTCP

  7. Thermally processed keratin films

    NASA Astrophysics Data System (ADS)

    Barone, Justin; Schmidt, Walter

    2004-03-01

    Keratin obtained from poultry feathers is blended with -OH containing second phases. Films are prepared by pressing the blended keratin at temperatures concurrent with typical polymer processing temperatures. The films are completely cohesive as opposed to partially cohesive if pressed under the same conditions without blending. The films are "tough" and the mechanical properties show similarities to the properties of commercially available commodity thermoplastics. The keratin films are produced in a few minutes without reducing or oxidizing agents. The mobility of the keratin chains during blending is shown to relate to the serine (S), threonine (T), and tyrosine (Y) contents in the amino acid sequence relative to cystine (C).

  8. Protective overcoating of films

    NASA Technical Reports Server (NTRS)

    Maas, K. A.

    1972-01-01

    Kodak Film Type SO-212 was emulsion overcoated with gelatin and lacquer to evaluate the feasibility of application of the coatings, any image degradation, and the relative protection offered against abrasion. Evaluated were: Eastman motion picture film lacquer Type 485, water solutions of Eastman purified Calfskin gelatin, and experimental Eastman gelatin stripping film of 4 and 6 microns. Conclusions reached were: (1) All coatings can be applied with relative ease with the only limitation being that of equipment. (2) None of the coatings degrade the processed image. (3) All of the coatings provide protection to the emulsion. These conclusions apply to any film which may be considered for overcoating.

  9. Droplet-mediated formation of embedded GaAs nanowires in MBE GaAs1-x Bi x films

    NASA Astrophysics Data System (ADS)

    Wood, Adam W.; Collar, Kristen; Li, Jincheng; Brown, April S.; Babcock, Susan E.

    2016-03-01

    We have examined the morphology and composition of embedded nanowires that can be formed during molecular beam epitaxy of GaAs1-x Bi x using high angle annular dark field (‘Z-contrast’) imaging in an aberration-corrected scanning transmission electron microscope. Samples were grown in Ga-rich growth conditions on a stationary GaAs substrate. Ga-rich droplets are observed on the surface with lateral trails extending from the droplet in the [110] direction. Cross-sectional scanning transmission electron microscopy of the film reveals epitaxial nanowire structures of composition ˜GaAs embedded in the GaAs1-x Bi x epitaxial layers. These nanowires extend from a surface droplet to the substrate at a shallow angle of inclination (˜4°). They typically are 4 μm long and have a lens-shaped cross section with major and minor axes dimensions of 800 and 120 nm. The top surface of the nanowires exhibits a linear trace in longitudinal cross-section, across which the composition change from ˜GaAs to GaAs1-x Bi x appears abrupt. The bottom surfaces of the nanowires appear wavy and the composition change appears to be graded over ˜25 nm. The droplets have phase separated into Ga- and Bi-rich components. A qualitative model is proposed in which Bi is gettered into Ga droplets, leaving Bi depleted nanowires in the wakes of the droplets as they migrate in one direction across the surface during GaAs1-x Bi x film growth.

  10. Film tension of liquid nano-film from molecular modeling

    NASA Astrophysics Data System (ADS)

    Peng, Tiefeng; Yang, Siyuan; Xiang, Fan; Liang, Yunpei; Li, Qibin; Gao, Xuechao; Liu, Sanjun

    2017-02-01

    Due to its geometry simplicity, the forces of thin liquid film are widely investigated and equivalently employed to explore the phys-chemical properties and mechanical stability of many other surfaces or colloid ensembles. The surface tension of bulk liquid (σ∞) and film tension (γ) are the most important parameters. Considering the insufficiency of detailed interpretation of film tension under micro-scale circumstances, a method for film tension was proposed based on numerical modeling. Assuming surface tension at different slab thicknesses being identical to the surface tension of film, the surface tension and disjoining pressure were subsequently used to evaluate the film tension based on the derivation of film thermodynamics, and a decreasing tendency was discovered for low temperature regions. The influence of saline concentration on nano-films was also investigated, and the comparison of film tensions suggested that higher concentration yielded larger film tension, with stronger decreasing intensity as a function of film thickness. Meanwhile, at thick film range (15-20 nm), film tension of higher concentration film continued to decrease as thickness increase, however it arrived to constant value for that of lower concentration. Finally, it was found that the film tension was almost independent on the film curvature, but varied with the thickness. The approach is applicable to symmetric emulsion films containing surfactants and bi-layer lipid films.

  11. The Possibility of Film Criticism.

    ERIC Educational Resources Information Center

    Poague, Leland; Cadbury, William

    1989-01-01

    Examines the role of critical language in film criticism. Compares and contrasts Monroe Beardsley's philosophy on film aesthetics with the New Criticism. Outlines some of the contributions Beardsley has made to the study of film criticism. (KM)

  12. Optical thin film devices

    NASA Astrophysics Data System (ADS)

    Mao, Shuzheng

    1991-11-01

    Thin film devices are applied to almost all modern scientific instruments, and these devices, especially optical thin film devices, play an essential role in the performances of the instruments, therefore, they are attracting more and more attention. Now there are numerous kinds of thin film devices and their applications are very diversified. The 300-page book, 'Thin Film Device and Applications,' by Prof. K. L. Chopra gives some general ideas, and my paper also outlines the designs, fabrication, and applications of some optical thin film devices made in my laboratory. Optical thin film devices have been greatly developed in the recent decades. Prof. A. Thelan has given a number of papers on the theory and techniques, Prof. H. A. Macleod's book, 'Thin Film Optical Filters,' has concisely concluded the important concepts of optical thin film devices, and Prof. J. A. Dobrowobski has proposed many successful designs for optical thin film devices. Recently, fully-automatic plants make it easier to produce thin film devices with various spectrum requirements, and some companies, such as Balzers, Leybold AG, Satis Vacuum AG, etc., have manufactured such kinds of coating plants for research or mass-production, and the successful example is the production of multilayer antireflection coatings with high stability and reproducibility. Therefore, it could be said that the design of optical thin film devices and coating plants is quite mature. However, we cannot expect that every problem has been solved, the R&D work still continues, the competition still continues, and new design concepts, new techniques, and new film materials are continually developed. Meanwhile, the high-price of fully-automatic coating plants makes unpopular, and automatic design of coating stacks is only the technique for optimizing the manual design according to the physical concepts and experience, in addition, not only the optical system, but also working environment should be taken into account when

  13. Microfilm--Which Film Type, Which Application?

    ERIC Educational Resources Information Center

    Dodson, Suzanne Cates

    1985-01-01

    Report on characteristics of different kinds of microfilm available indicates proper film for specific needs. Silver halide and nonsilver films, diazo film, vesicular film, reaction of films to light, effect of heat and humidity on films, film susceptibility to scratching, and potential longevity of film types are covered. (35 references) (EJS)

  14. Water depth penetration film test

    NASA Technical Reports Server (NTRS)

    Lockwood, H. E.; Perry, L.; Sauer, G. E.; Lamar, N. T.

    1974-01-01

    As part of the National Aeronautics and Space Administration Earth Resources Program, a comparative and controlled evaluation of nine film-filter combinations was completed to establish the relative effectiveness in recording water subsurface detail if exposed from an aerial platform over a typical water body. The films tested, with one exception, were those which prior was suggested had potential. These included an experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and a black-and-white infrared film. Selective filtration was used with all films.

  15. Thin-film forces in pseudoemulsion films

    SciTech Connect

    Bergeron, V.; Radke, C.J. |

    1991-06-01

    Use of foam for enhanced oil recovery (EOR) has shown recent success in steam-flooding field applications. Foam can also provide an effective barrier against gas coning in thin oil zones. Both of these applications stem from the unique mobility-control properties a stable foam possesses when it exists in porous media. Unfortunately, oil has a major destabilizing effect on foam. Therefore, it is important for EOR applications to understand how oil destroys foam. Studies all indicate that stabilization of the pseudoemulsion film is critical to maintain foam stability in the presence of oil. Hence, to aid in design of surfactant formulations for foam insensitivity to oil the authors pursue direct measurement of the thin-film or disjoining forces that stabilize pseudoemulsion films. Experimental procedures and preliminary results are described.

  16. Creative Film-Making.

    ERIC Educational Resources Information Center

    Smallman, Kirk

    The fundamentals of motion picture photography are introduced with a physiological explanation for the illusion of motion in a film. Film stock formats and emulsions, camera features, and lights are listed and described. Various techniques of exposure control are illustrated in terms of their effects. Photographing action with a stationary or a…

  17. Abstract Film and Beyond.

    ERIC Educational Resources Information Center

    Le Grice, Malcolm

    A theoretical and historical account of the main preoccupations of makers of abstract films is presented in this book. The book's scope includes discussion of nonrepresentational forms as well as examination of experiments in the manipulation of time in films. The ten chapters discuss the following topics: art and cinematography, the first…

  18. Film Canister Science

    ERIC Educational Resources Information Center

    Ferstl, Andrew; Schneider, Jamie L.

    2007-01-01

    Opaque film canisters are readily available, cheap, and useful for scientific inquiry in the classroom. They can also be surprisingly versatile and useful as a tool for stimulating scientific inquiry. In this article, the authors describe inquiry activities using film canisters for preservice teachers, including a "black box" activity and several…

  19. Films for Childhood Educators.

    ERIC Educational Resources Information Center

    Winick, Mariann Pezzella

    This is a review of films in six thematic groupings: (1) The Open Classroom on Film, (2) The Developing Child, (3) Readiness and the Natural Abilities of Children, (4) Schools as Mirrors, (5) Families: Weavers of Civilization, (6) Children: The Legacy. Each review describes strengths and weaknesses, and gives guidance for follow-up usage. All…

  20. Authors on Film.

    ERIC Educational Resources Information Center

    Geduld, Harry M., Ed.

    Different authors' attitudes toward film are revealed through five different sections of this book: (1) articles, essays, and reviews pertaining to the silent cinema and the transition to sound; (2) general statements on the film medium or filmmakers and their messages; (3) essays dealing with the problems, involvements, and reflections of the…

  1. Construction of Meaning: Film.

    ERIC Educational Resources Information Center

    Pryluck, Calvin

    1995-01-01

    Notes that film has no clear set of rules, unlike all languages, which are deductive systems interpreted according to clear sets of rules. Suggests that film is an inductive system whose interpretation is based on a general understanding of events depicted as modified by production variables such as lighting, camera angles, and the context of…

  2. Protolytic carbon film technology

    SciTech Connect

    Renschler, C.L.; White, C.A.

    1996-04-01

    This paper presents a technique for the deposition of polyacrylonitrile (PAN) on virtually any surface allowing carbon film formation with only the caveat that the substrate must withstand carbonization temperatures of at least 600 degrees centigrade. The influence of processing conditions upon the structure and properties of the carbonized film is discussed. Electrical conductivity, microstructure, and morphology control are also described.

  3. FAA Film Catalog.

    ERIC Educational Resources Information Center

    Federal Aviation Administration (DOT), Washington, DC.

    Some 75 films from the U.S. Department of Transportation's Federal Aviation Administration are listed in this catalog. Topics dealt with include aerodynamics, airports, aviation history and careers, flying clubs, navigation and weather. Most of the films are 16mm sound and color productions. Filmstrips requiring a 35mm projector and phonograph or…

  4. Stabilized chromium oxide film

    DOEpatents

    Nyaiesh, A.R.; Garwin, E.L.

    1986-08-04

    Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150A are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.

  5. Stabilized chromium oxide film

    DOEpatents

    Garwin, Edward L.; Nyaiesh, Ali R.

    1988-01-01

    Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150.ANG. are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.

  6. Dental Training Films.

    ERIC Educational Resources Information Center

    Veterans Administration Medical Center, Washington, DC.

    This dental training films catalog is organized into two sections. Section I is a category listing of the films by number and title, indexed according to generalized headings; categories are as follow: anatomy, articulator systems, complete dentures, dental assisting, dental laboratory technology, dental materials, dental office emergencies,…

  7. Radiographic film package

    SciTech Connect

    Muylle, W. E.

    1985-08-27

    A radiographic film package for non-destructive testing, comprising a radiographic film sheet, an intensifying screen with a layer of lead bonded to a paper foil, and a vacuum heat-sealed wrapper with a layer of aluminum and a heat-sealed easy-peelable thermoplastic layer.

  8. On Teaching Ethnographic Film

    ERIC Educational Resources Information Center

    Clarfield, Geoffrey

    2013-01-01

    The author of this article, a developmental anthropologist, illustrates how the instructor can use ethnographic films to enhance the study of anthropology and override notions about the scope and efficacy of Western intervention in the Third World, provided the instructor places such films in their proper historical and cultural context. He…

  9. Film and the Humanities.

    ERIC Educational Resources Information Center

    O'Connor, John E., Ed.

    This report on a conference, which brought together representatives of various humanistic disciplines to explore the cross-disciplinary appeal of film study as well as the use of film in stimulating scholarship and teaching, includes a narrative summary of the day's conversations and issues raised, as well as of reprints of articles that suggest…

  10. Thick film hydrogen sensor

    DOEpatents

    Hoffheins, Barbara S.; Lauf, Robert J.

    1995-01-01

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  11. Thick film hydrogen sensor

    DOEpatents

    Hoffheins, B.S.; Lauf, R.J.

    1995-09-19

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors. 8 figs.

  12. Mechanics of Thin Films

    DTIC Science & Technology

    1992-02-06

    S. Hwang, Thermal conductivity of thin films: measurement and microstructural effects, in Thin- film heat transfer, properties and processing, ed...thermal, electrical, optical and magnetic properties . As typical examples we mention microelectronics, optical coatings and multilayers for use in optical...interplay between mechanical properties (elastic moduli), thermal properties (thermal conductivity, thermal expansion coefficient), and optical

  13. Filming for Television.

    ERIC Educational Resources Information Center

    Englander, A. Arthur; Petzold, Paul

    Film makers, professional or amateur, will find in this volume an extensive discussion of the adaptation of film technique to television work, of the art of the camera operator, and of the productive relationships between people, organization, and hardware. Chapters include "The Beginnings," an overview of the interrelationship between roles in…

  14. Film Study Hang Ups.

    ERIC Educational Resources Information Center

    Grenier, Charles F.

    1969-01-01

    The interest and delight which students find in film should be preserved from a teacher's excessive zeal to analyze and explain. As the beauty of poetry is frequently diminished through exhaustive analyses of similes, rhyme schemes, and other technical devices, the value of film to high school students can be weakened through too great an emphasis…

  15. Selective inorganic thin films

    SciTech Connect

    Phillips, M.L.F.; Weisenbach, L.A.; Anderson, M.T.

    1995-05-01

    This project is developing inorganic thin films as membranes for gas separation applications, and as discriminating coatings for liquid-phase chemical sensors. Our goal is to synthesize these coatings with tailored porosity and surface chemistry on porous substrates and on acoustic and optical sensors. Molecular sieve films offer the possibility of performing separations involving hydrogen, air, and natural gas constituents at elevated temperatures with very high separation factors. We are focusing on improving permeability and molecular sieve properties of crystalline zeolitic membranes made by hydrothermally reacting layered multicomponent sol-gel films deposited on mesoporous substrates. We also used acoustic plate mode (APM) oscillator and surface plasmon resonance (SPR) sensor elements as substrates for sol-gel films, and have both used these modified sensors to determine physical properties of the films and have determined the sensitivity and selectivity of these sensors to aqueous chemical species.

  16. The National Film Registry: Acquiring Our Film Heritage.

    ERIC Educational Resources Information Center

    Ziegler, Roy A.

    The National Film Registry, which is primarily a designated list of films to be preserved by the Library of Congress, is also a valuable tool for selecting "films that are culturally, historically, and aesthetically significant." Following a brief discussion of the history and selection process of the National Film Registry, Southeast…

  17. Film Theory and Hugo Munsterberg's "The Film": A Psychological Study.

    ERIC Educational Resources Information Center

    Wicclair, Mark R.

    1978-01-01

    Hugo Munsterberg's "The Film: A Psychological Study" is one of the earliest essays in the area of film theory. Unfortunately, it has remained relatively unknown since its publication in 1916. The author discusses two concepts raised by Munsterberg: the contrast between films in the theatrical mode and films in the cinematic mode.…

  18. Chiral atomically thin films.

    PubMed

    Kim, Cheol-Joo; Sánchez-Castillo, A; Ziegler, Zack; Ogawa, Yui; Noguez, Cecilia; Park, Jiwoong

    2016-06-01

    Chiral materials possess left- and right-handed counterparts linked by mirror symmetry. These materials are useful for advanced applications in polarization optics, stereochemistry and spintronics. In particular, the realization of spatially uniform chiral films with atomic-scale control of their handedness could provide a powerful means for developing nanodevices with novel chiral properties. However, previous approaches based on natural or grown films, or arrays of fabricated building blocks, could not offer a direct means to program intrinsic chiral properties of the film on the atomic scale. Here, we report a chiral stacking approach, where two-dimensional materials are positioned layer-by-layer with precise control of the interlayer rotation (θ) and polarity, resulting in tunable chiral properties of the final stack. Using this method, we produce left- and right-handed bilayer graphene, that is, a two-atom-thick chiral film. The film displays one of the highest intrinsic ellipticity values (6.5 deg μm(-1)) ever reported, and a remarkably strong circular dichroism (CD) with the peak energy and sign tuned by θ and polarity. We show that these chiral properties originate from the large in-plane magnetic moment associated with the interlayer optical transition. Furthermore, we show that we can program the chiral properties of atomically thin films layer-by-layer by producing three-layer graphene films with structurally controlled CD spectra.

  19. Chiral atomically thin films

    NASA Astrophysics Data System (ADS)

    Kim, Cheol-Joo; Sánchez-Castillo, A.; Ziegler, Zack; Ogawa, Yui; Noguez, Cecilia; Park, Jiwoong

    2016-06-01

    Chiral materials possess left- and right-handed counterparts linked by mirror symmetry. These materials are useful for advanced applications in polarization optics, stereochemistry and spintronics. In particular, the realization of spatially uniform chiral films with atomic-scale control of their handedness could provide a powerful means for developing nanodevices with novel chiral properties. However, previous approaches based on natural or grown films, or arrays of fabricated building blocks, could not offer a direct means to program intrinsic chiral properties of the film on the atomic scale. Here, we report a chiral stacking approach, where two-dimensional materials are positioned layer-by-layer with precise control of the interlayer rotation (θ) and polarity, resulting in tunable chiral properties of the final stack. Using this method, we produce left- and right-handed bilayer graphene, that is, a two-atom-thick chiral film. The film displays one of the highest intrinsic ellipticity values (6.5 deg μm-1) ever reported, and a remarkably strong circular dichroism (CD) with the peak energy and sign tuned by θ and polarity. We show that these chiral properties originate from the large in-plane magnetic moment associated with the interlayer optical transition. Furthermore, we show that we can program the chiral properties of atomically thin films layer-by-layer by producing three-layer graphene films with structurally controlled CD spectra.

  20. Feature Films in Your Library

    ERIC Educational Resources Information Center

    Spehr, Paul

    1970-01-01

    Trained film librarians, given a well planned and carefully developed program can answer the needs of the new film students. Includes lists of motion picture distributors, cinema periodicals, significant feature films, and classic American feature-length films. (Author/JB)

  1. Film Images of Private Schools.

    ERIC Educational Resources Information Center

    Resnick, David

    2000-01-01

    Examines public debate over private education in the context of the Hollywood dramatic feature film. Analyses four recent films that all portray private schools negatively. Film representation of public schools is more optimistic. Asserts that the films ignore or misrepresent three strengths of private education: effective leadership, small school…

  2. Reference for radiographic film interpreters

    NASA Technical Reports Server (NTRS)

    Austin, D. L.

    1970-01-01

    Reference of X-ray film images provides examples of weld defects, film quality, stainless steel welded tubing, and acceptable weld conditions. A summary sheet details the discrepancies shown on the film strip. This reference aids in interpreting and evaluating radiographic film of weldments.

  3. Film: The Reality of Being.

    ERIC Educational Resources Information Center

    Sheratsky, Rodney E.

    The visual media, particularly film, has challenged today's educators by competing for students' time and interests and by providing a relevancy that books designed for school use do not have. Using film study to combat the supposed immorality of theatrical films and employing instructional film to transmit information has provided a negative…

  4. The Art of the Film.

    ERIC Educational Resources Information Center

    Lindgren, Ernest

    The author prefaces his consideration of films as an art form with a discussion of the mechanics of filmmaking. He describes the division of talent on a movie set, details the history of the tools of filmmakers, and explains the production and reproduction of a film. The influence of film techniques on plot development in a fiction film is…

  5. Children's Film Programming: A Handbook.

    ERIC Educational Resources Information Center

    Gallery Association of New York State, Inc.

    Directed at the staffs of art institutions, community centers, libraries, historical societies, and schools, this practical guide is intended to help in the selection and use of films for children. "Film," in this handbook refers to 16mm films presented in public screenings--not videotape versions of films, and not material originally…

  6. Diagnosing Disputes in Film Criticism.

    ERIC Educational Resources Information Center

    Schultz, Robert A.

    1979-01-01

    By classifying and analyzing actual disputes in film criticism, the author considers the following questions: Are there connections between film theory and film criticism? If so, which are healthy and which are diseased? If not, what alternative healthy function might film theory have? (Author/SJL)

  7. Biomimetic thin film synthesis

    SciTech Connect

    Graff, G.L.; Campbell, A.A.; Gordon, N.R.

    1995-05-01

    The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

  8. Thin film hydrogen sensor

    DOEpatents

    Cheng, Yang-Tse; Poli, Andrea A.; Meltser, Mark Alexander

    1999-01-01

    A thin film hydrogen sensor, includes: a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end.

  9. Thin film hydrogen sensor

    DOEpatents

    Cheng, Y.T.; Poli, A.A.; Meltser, M.A.

    1999-03-23

    A thin film hydrogen sensor includes a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end. 5 figs.

  10. Negative birefringent polyimide films

    NASA Technical Reports Server (NTRS)

    Harris, Frank W. (Inventor); Cheng, Stephen Z. D. (Inventor)

    1994-01-01

    A negative birefringent film, useful in liquid crystal displays, and a method for controlling the negative birefringence of a polyimide film is disclosed which allows the matching of an application to a targeted amount of birefringence by controlling the degree of in-plane orientation of the polyimide by the selection of functional groups within both the diamine and dianhydride segments of the polyimide which affect the polyimide backbone chain rigidity, linearity, and symmetry. The higher the rigidity, linearity and symmetry of the polyimide backbone, the larger the value of the negative birefringence of the polyimide film.

  11. Ultrahard carbon nanocomposite films

    SciTech Connect

    SIEGAL,MICHAEL P.; TALLANT,DAVID R.; PROVENCIO,PAULA P.; OVERMYER,DONALD L.; SIMPSON,REGINA L.; MARTINEZ-MIRANDA,L.J.

    2000-01-27

    Modest thermal annealing to 600 C of diamondlike amorphous-carbon (a-C) films grown at room temperature results in the formation of carbon nanocomposites with hardness similar to diamond. These nanocomposite films consist of nanometer-sized regions of high density a-C embedded in an a-C matrix with a reduced density of 5--10%. The authors report on the evolution of density and bonding topologies as a function of annealing temperature. Despite a decrease in density, film hardness actually increases {approximately} 15% due to the development of the nanocomposite structure.

  12. Ion beam deposited protective films

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.

    1981-01-01

    Single or dual ion beam sources were used to deposit thin films for different applications. Metal and metal oxide films were evaluated as protective coatings for the materials. Film adherence was measured and the most promising films were then tested under environments similar to operating conditions. It was shown that some materials do protect die material (H-13 steel) and do reduce thermal fatigue. Diamondlike films have many useful applications. A series of experiments were conducted to define and optimize new approaches to the manufacture of such films. A dual beam system using argon and methane gases was developed to generate these films.

  13. Magnetron sputtered boron films

    DOEpatents

    Makowiecki, D.M.; Jankowski, A.F.

    1998-06-16

    A method is described for the production of thin boron and titanium/boron films by magnetron sputter deposition. The amorphous boron films contain no morphological growth features, unlike those found when thin films are prepared by various physical vapor deposition processes. Magnetron sputter deposition method requires the use of a high density crystalline boron sputter target which is prepared by hot isostatic pressing. Thin boron films prepared by this method are useful for producing hardened surfaces, surfacing machine tools, etc. and for ultra-thin band pass filters as well as the low Z element in low Z/high Z optical components, such as mirrors which enhance reflectivity from grazing to normal incidence. 8 figs.

  14. Magnetron sputtered boron films

    DOEpatents

    Makowiecki, Daniel M.; Jankowski, Alan F.

    1998-01-01

    A method is described for the production of thin boron and titanium/boron films by magnetron sputter deposition. The amorphous boron films contain no morphological growth features, unlike those found when thin films are prepared by various physical vapor deposition processes. Magnetron sputter deposition method requires the use of a high density crystalline boron sputter target which is prepared by hot isostatic pressing. Thin boron films prepared by this method are useful for producing hardened surfaces, surfacing machine tools, etc. and for ultra-thin band pass filters as well as the low Z element in low Z/high Z optical components, such as mirrors which enhance reflectivity from grazing to normal incidence.

  15. TAMPERPROOF FILM BADGE

    DOEpatents

    Kocher, L.F.

    1958-10-01

    A persornel dosimeter film badge made of plastic, with provision for a picture of the wearer and an internal slide containing photographic film that is sensitive to various radiations, is described. Four windows made of differing material selectively attenuate alpha, beta, gamma rays, and neutrons so as to distinguish the particular type of radiation the wearer was subjected to. In addition, a lead shield has the identification number of the wearer perforated thereon so as to identify the film after processing. An internal magnetically actuated latch securely locks the slide within the body, and may be withdrawn only upon the external application of two strong magnetic forces in order to insure that the wearer or other curious persons will not accidentally expose the film to visual light.

  16. Sprites on Film

    NASA Video Gallery

    Filmed at 10,000 frames per second by Japan's NHK television, movies like this of electromagnetic bursts called "sprites" will help scientists better understand how weather high in the atmosphere r...

  17. Amorphous diamond films

    DOEpatents

    Falabella, S.

    1998-06-09

    Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions. 1 fig.

  18. Nanostructured thermoplastic polyimide films

    DOEpatents

    Aglan, Heshmat

    2015-05-19

    Structured films containing multi-walled carbon nanotubes ("MWCNTs") have enhanced mechanical performance in terms of strength, fracture resistance, and creep recovery of polyimide ("PI") films. Preferably, the loadings of MWCNTs can be in the range of 0.1 wt % to 0.5 wt %. The strength of the new PI films dried at 60.degree. C. increased by 55% and 72% for 0.1 wt % MWCNT and 0.5 wt % MWCNT loadings, respectively, while the fracture resistance increased by 23% for the 0.1 wt % MWCNTs and then decreases at a loading of 0.5 wt % MWCNTs. The films can be advantageously be created by managing a corresponding shift in the annealing temperature at which the maximum strength occurs as the MWCNT loadings increase.

  19. Multifunctional thin film surface

    DOEpatents

    Brozik, Susan M.; Harper, Jason C.; Polsky, Ronen; Wheeler, David R.; Arango, Dulce C.; Dirk, Shawn M.

    2015-10-13

    A thin film with multiple binding functionality can be prepared on an electrode surface via consecutive electroreduction of two or more aryl-onium salts with different functional groups. This versatile and simple method for forming multifunctional surfaces provides an effective means for immobilization of diverse molecules at close proximities. The multifunctional thin film has applications in bioelectronics, molecular electronics, clinical diagnostics, and chemical and biological sensing.

  20. Oxide Films RF Applications

    DTIC Science & Technology

    2006-06-01

    different stabilities and properties . Certain applications, such as integrated dielectrics or photoelectrochemical cells, require thin films of TiO2 that...interesting dielectric properties . Another is that the (001) plane of anatase TiO2 is one of the two main layers stacked along the (100) direction in...Public Release 13. SUPPLEMENTARY NOTES .bDib ibuUl I U 1 iited 14. ABSTRACT TiO2 films were grown using a reactive molecular beam epitaxy system

  1. Thin film tritium dosimetry

    DOEpatents

    Moran, Paul R.

    1976-01-01

    The present invention provides a method for tritium dosimetry. A dosimeter comprising a thin film of a material having relatively sensitive RITAC-RITAP dosimetry properties is exposed to radiation from tritium, and after the dosimeter has been removed from the source of the radiation, the low energy electron dose deposited in the thin film is determined by radiation-induced, thermally-activated polarization dosimetry techniques.

  2. Magnetoresistance of Au films

    DOE PAGES

    Zhang, D. L.; Song, X. H.; Zhang, X.; ...

    2014-12-10

    Measurement of the magnetoresistance (MR) of Au films as a function of temperature and film thickness reveals a strong dependence on grain size distribution and clear violation of the Kohler s rule. Using a model of random resistor network, we show that this result can be explained if the MR arises entirely from inhomogeneity due to grain boundary scattering and thermal activation of grain boundary atoms.

  3. Dielectric Composite Thin Films

    DTIC Science & Technology

    1989-11-01

    more compressive under deposition conditions, such as high temperature, low pressure or energetic ion bombardment, that produce a more densely packed...film porosity and silica content. Thus, films formed at high temperatures and low pressures , as well as under ion bombardment during deposition, have...and their mixtures were deposited on 100-300 *C substrates and under reactive gas III. RESULTS pressures of 1-10x 10- Torr 02. 02 was UHP grade with A

  4. Polymer film composite transducer

    DOEpatents

    Owen, Thomas E.

    2005-09-20

    A composite piezoelectric transducer, whose piezoeletric element is a "ribbon wound" film of piezolectric material. As the film is excited, it expands and contracts, which results in expansion and contraction of the diameter of the entire ribbon winding. This is accompanied by expansion and contraction of the thickness of the ribbon winding, such that the sound radiating plate may be placed on the side of the winding.

  5. Multiresonant layered plasmonic films

    SciTech Connect

    DeVetter, Brent M.; Bernacki, Bruce E.; Bennett, Wendy D.; Schemer-Kohrn, Alan; Alvine, Kyle J.

    2017-01-01

    Multi-resonant nanoplasmonic films have numerous applications in areas such as nonlinear optics, sensing, and tamper indication. While techniques such as focused ion beam milling and electron beam lithography can produce high-quality multi-resonant films, these techniques are expensive, serial processes that are difficult to scale at the manufacturing level. Here, we present the fabrication of multi-resonant nanoplasmonic films using a layered stacking technique. Periodically-spaced gold nanocup substrates were fabricated using self-assembled polystyrene nanospheres followed by oxygen plasma etching and metal deposition via magnetron sputter coating. By adjusting etch parameters and initial nanosphere size, it was possible to achieve an optical response ranging from the visible to the near-infrared. Singly resonant, flexible films were first made by performing peel-off using an adhesive-coated polyolefin film. Through stacking layers of the nanofilm, we demonstrate fabrication of multi-resonant films at a fraction of the cost and effort as compared to top-down lithographic techniques.

  6. A high-Q resonant pressure microsensor with through-glass electrical interconnections based on wafer-level MEMS vacuum packaging.

    PubMed

    Luo, Zhenyu; Chen, Deyong; Wang, Junbo; Li, Yinan; Chen, Jian

    2014-12-16

    This paper presents a high-Q resonant pressure microsensor with through-glass electrical interconnections based on wafer-level MEMS vacuum packaging. An approach to maintaining high-vacuum conditions by integrating the MEMS fabrication process with getter material preparation is presented in this paper. In this device, the pressure under measurement causes a deflection of a pressure-sensitive silicon square diaphragm, which is further translated to stress build up in "H" type doubly-clamped micro resonant beams, leading to a resonance frequency shift. The device geometries were optimized using FEM simulation and a 4-inch SOI wafer was used for device fabrication, which required only three photolithographic steps. In the device fabrication, a non-evaporable metal thin film as the getter material was sputtered on a Pyrex 7740 glass wafer, which was then anodically bonded to the patterned SOI wafer for vacuum packaging. Through-glass via holes predefined in the glass wafer functioned as the electrical interconnections between the patterned SOI wafer and the surrounding electrical components. Experimental results recorded that the Q-factor of the resonant beam was beyond 22,000, with a differential sensitivity of 89.86 Hz/kPa, a device resolution of 10 Pa and a nonlinearity of 0.02% F.S with the pressure varying from 50 kPa to 100 kPa. In addition, the temperature drift coefficient was less than -0.01% F.S/°C in the range of -40 °C to 70 °C, the long-term stability error was quantified as 0.01% F.S over a 5-month period and the accuracy of the microsensor was better than 0.01% F.S.

  7. A High-Q Resonant Pressure Microsensor with Through-Glass Electrical Interconnections Based on Wafer-Level MEMS Vacuum Packaging

    PubMed Central

    Luo, Zhenyu; Chen, Deyong; Wang, Junbo; Li, Yinan; Chen, Jian

    2014-01-01

    This paper presents a high-Q resonant pressure microsensor with through-glass electrical interconnections based on wafer-level MEMS vacuum packaging. An approach to maintaining high-vacuum conditions by integrating the MEMS fabrication process with getter material preparation is presented in this paper. In this device, the pressure under measurement causes a deflection of a pressure-sensitive silicon square diaphragm, which is further translated to stress build up in “H” type doubly-clamped micro resonant beams, leading to a resonance frequency shift. The device geometries were optimized using FEM simulation and a 4-inch SOI wafer was used for device fabrication, which required only three photolithographic steps. In the device fabrication, a non-evaporable metal thin film as the getter material was sputtered on a Pyrex 7740 glass wafer, which was then anodically bonded to the patterned SOI wafer for vacuum packaging. Through-glass via holes predefined in the glass wafer functioned as the electrical interconnections between the patterned SOI wafer and the surrounding electrical components. Experimental results recorded that the Q-factor of the resonant beam was beyond 22,000, with a differential sensitivity of 89.86 Hz/kPa, a device resolution of 10 Pa and a nonlinearity of 0.02% F.S with the pressure varying from 50 kPa to 100 kPa. In addition, the temperature drift coefficient was less than −0.01% F.S/°C in the range of −40 °C to 70 °C, the long-term stability error was quantified as 0.01% F.S over a 5-month period and the accuracy of the microsensor was better than 0.01% F.S. PMID:25521385

  8. EXPERIENCE IN REDUCING ELECTRON CLOUD AND DYNAMIC PRESSURE RISE IN WARM AND COLD REGIONS IN RHIC.

    SciTech Connect

    ZHANG, S.Y.; AHRENS,L.; ALLESI, J.; BAI, M.; BLASKIEWICZ, M.; CAMERON, P.; CONNOLLY, R.; DREES, A.; FISCHER, W.; GULLOTTA, J.; HE, P.; HSEUH, H.C.; HUANG, H.; LEE, R.; LITVINENKO, V.; MACKAY, W.W.; MONTAG, C.; NICOLETTI, A.; OERTER, B.; PILAT, F.; PTITSYN, V.; ROSER, T.; SATOGATA, T.; SMART, L.; SYNDSTRUP, L.; TEPIKIAN, S.; THIEBERGER, P.; TRBOJEVIC, D.; WEI, J.; ZENO, K.

    2006-06-23

    The large scale application of non-evaporable getter coating in RHIC has been effective in reducing the electron cloud. Since beams with higher intensity and smaller bunch spacing became possible in operation, the emittance growth is of concern. Study results are reported together with experiences of machine improvements: saturated NEG coatings, anti-grazing ridges in warm sections, and the pre-pumping in cryogenic regions.

  9. Capacitor film surface assessment studies

    NASA Astrophysics Data System (ADS)

    Galperin, I.; White, W.

    1985-02-01

    In the present investigation of the optical surface of the three widely used, biaxially oriented capacitor films, polypropylene, polyvinylidene fluoride, and polyester, with attention to film surface defects and thickness variation, the defects and their rate of occurrence proved traceable in terms of polymer structure, chemical grouping, and fabrication processing. Film thickness variation was small, yet differed for each film type. Film breakdown voltages have been determined, and alternative causes for the voltage values obtained are proposed. A reciprocal relation is noted between the film breakdown voltage and the dielectric constant.

  10. Droplet-mediated formation of embedded GaAs nanowires in MBE GaAs(1-x)Bi(x) films.

    PubMed

    Wood, Adam W; Collar, Kristen; Li, Jincheng; Brown, April S; Babcock, Susan E

    2016-03-18

    We have examined the morphology and composition of embedded nanowires that can be formed during molecular beam epitaxy of GaAs(1-x)Bi(x) using high angle annular dark field ('Z-contrast') imaging in an aberration-corrected scanning transmission electron microscope. Samples were grown in Ga-rich growth conditions on a stationary GaAs substrate. Ga-rich droplets are observed on the surface with lateral trails extending from the droplet in the [110] direction. Cross-sectional scanning transmission electron microscopy of the film reveals epitaxial nanowire structures of composition ∼GaAs embedded in the GaAs(1-x)Bi(x) epitaxial layers. These nanowires extend from a surface droplet to the substrate at a shallow angle of inclination (∼4°). They typically are 4 μm long and have a lens-shaped cross section with major and minor axes dimensions of 800 and 120 nm. The top surface of the nanowires exhibits a linear trace in longitudinal cross-section, across which the composition change from ∼GaAs to GaAs(1-x)Bi(x) appears abrupt. The bottom surfaces of the nanowires appear wavy and the composition change appears to be graded over ∼25 nm. The droplets have phase separated into Ga- and Bi-rich components. A qualitative model is proposed in which Bi is gettered into Ga droplets, leaving Bi depleted nanowires in the wakes of the droplets as they migrate in one direction across the surface during GaAs(1-x)Bi(x) film growth.

  11. Epitaxial thin films

    DOEpatents

    Hunt, Andrew Tye; Deshpande, Girish; Lin, Wen-Yi; Jan, Tzyy-Jiuan

    2006-04-25

    Epitatial thin films for use as buffer layers for high temperature superconductors, electrolytes in solid oxide fuel cells (SOFC), gas separation membranes or dielectric material in electronic devices, are disclosed. By using CCVD, CACVD or any other suitable deposition process, epitaxial films having pore-free, ideal grain boundaries, and dense structure can be formed. Several different types of materials are disclosed for use as buffer layers in high temperature superconductors. In addition, the use of epitaxial thin films for electrolytes and electrode formation in SOFCs results in densification for pore-free and ideal gain boundary/interface microstructure. Gas separation membranes for the production of oxygen and hydrogen are also disclosed. These semipermeable membranes are formed by high-quality, dense, gas-tight, pinhole free sub-micro scale layers of mixed-conducting oxides on porous ceramic substrates. Epitaxial thin films as dielectric material in capacitors are also taught herein. Capacitors are utilized according to their capacitance values which are dependent on their physical structure and dielectric permittivity. The epitaxial thin films of the current invention form low-loss dielectric layers with extremely high permittivity. This high permittivity allows for the formation of capacitors that can have their capacitance adjusted by applying a DC bias between their electrodes.

  12. Dewetting of Thin Polymer Films

    NASA Astrophysics Data System (ADS)

    Dixit, P. S.; Sorensen, J. L.; Kent, M.; Jeon, H. S.

    2001-03-01

    DEWETTING OF THIN POLYMER FILMS P. S. Dixit,(1) J. L. Sorensen,(2) M. Kent,(2) H. S. Jeon*(1) (1) Department of Petroleum and Chemical Engineering, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801, jeon@nmt.edu (2) Department 1832, Sandia National Laboratories, Albuquerque, NM. Dewetting of thin polymer films is of technological importance for a variety of applications such as protective coatings, dielectric layers, and adhesives. Stable and smooth films are required for the above applications. Above the glass transition temperature (Tg) the instability of polymer thin films on a nonwettable substrate can be occurred. The dewetting mechanism and structure of polypropylene (Tg = -20 ^circC) and polystyrene (Tg = 100 ^circC) thin films is investigated as a function of film thickness (25 Åh < 250 Åand quenching temperature. Contact angle measurements are used in conjunction with optical microscope to check the surface homogeneity of the films. Uniform thin films are prepared by spin casting the polymer solutions onto silicon substrates with different contact angles. We found that the stable and unstable regions of the thin films as a function of the film thickness and quenching temperature, and then constructed a stability diagram for the dewetting of thin polymer films. We also found that the dewetting patterns of the thin films are affected substantially by the changes of film thickness and quenching temperature.

  13. Virus-PEDOT Biocomposite Films

    PubMed Central

    Donavan, Keith C.; Arter, Jessica A.

    2012-01-01

    Virus-poly(3,4-ethylenedioxythiophene) (virus-PEDOT) biocomposite films are prepared by electropolymerizing 3,4-ethylenedioxythiophene (EDOT) in aqueous electrolytes containing 12 mM LiClO4 and the bacteriophage M13. The concentration of virus in these solutions, [virus]soln, is varied from 3 nM to 15 nM. A quartz crystal microbalance is used to directly measure the total mass of the biocomposite film during its electrodeposition. In combination with a measurement of the electrodeposition charge, the mass of the virus incorporated into the film is calculated. These data show that concentration of the M13 within the electropolymerized film, [virus]film, increases linearly with [virus]soln. The incorporation of virus particles into the PEDOT film from solution is efficient, resulting in a concentration ratio: [virus]film:[virus]soln ≈450. Virus incorporation into the PEDOT causes roughening of the film topography that is observed using scanning electron microscopy and atomic force microscopy (AFM). The electrical conductivity of the virus-PEDOT film, measured perpendicular to the plane of the film using conductive tip AFM, decreases linearly with virus loading, from 270 μS/cm for pure PE-DOT films to 50 μS/cm for films containing 100 μM virus. The presence on the virus surface of displayed affinity peptides did not significantly influence the efficiency of incorporation into virus-PEDOT biocomposite films. PMID:22856875

  14. Filming eugenics: teaching the history of eugenics through film.

    PubMed

    Ooten, Melissa; Trembanis, Sarah

    2007-01-01

    In teaching eugenics to undergraduate students and general public audiences, film should he considered as a provocative and fruitful medium that can generate important discussions about the intersections among eugenics, gender, class, race, and sexuality. This paper considers the use of two films, A Bill of Divorcement and The Lynchburg Story, as pedagogical tools for the history of eugenics. The authors provide background information on the films and suggestions for using the films to foster an active engagement with the historical eugenics movement.

  15. Thin films and uses

    DOEpatents

    Baskaran, Suresh; Graff, Gordon L.; Song, Lin

    1998-01-01

    The invention provides a method for synthesizing a titanium oxide-containing film comprising the following steps: (a) preparing an aqueous solution of a titanium chelate with a titanium molarity in the range of 0.01M to 0.6M. (b) immersing a substrate in the prepared solution, (c) decomposing the titanium chelate to deposit a film on the substrate. The titanium chelate maybe decomposed acid, base, temperature or other means. A preferred method provides for the deposit of adherent titanium oxide films from C2 to C5 hydroxy carboxylic acids. In another aspect the invention is a novel article of manufacture having a titanium coating which protects the substrate against ultraviolet damage. In another aspect the invention provides novel semipermeable gas separation membranes, and a method for producing them.

  16. Holographic thin film analyzer

    NASA Technical Reports Server (NTRS)

    Williams, J. R.; Norden, B. N. (Inventor)

    1973-01-01

    A system for the analysis and measurement of thin films in which the light output of a laser is split into two beams is discribed. The first beam is focused to illuminate the entire area of a photographic plate and the second beam is colummated and directed through a relatively small portion of the photographic plate onto the sample with the film to be observed. The surface of the sample is positioned at a slight angle with respect to a plane normal to the second beam and the light reflected from the sample arrives back at the photographic plate in a region other than through which the second beam originally passes. By making two successive exposures during the deposition of material on the surface of the sample, holograms are recorded on the photographic plate. The plate is then developed and interference lines of the hologram provide a measurement of the film or material deposited between exposure.

  17. Thin θ -film optics

    NASA Astrophysics Data System (ADS)

    Huerta, Luis

    2016-12-01

    A Chern-Simons theory in 3D is accomplished by the so-called θ term in the action (θ /2 )∫F ∧F , which contributes only to observable effects on the boundaries of such a system. When electromagnetic radiation interacts with the system, the wave is reflected and its polarization is rotated at the interface, even when both the θ system and the environment are pure vacuum. These topics have been studied extensively. Here, we investigate the optical properties of a thin θ film, where multiple internal reflections could interfere coherently. The cases of pure vacuum and a material with magnetoelectric properties are analyzed. It is found that the film reflectance is enhanced compared to ordinary non-θ systems and the interplay between magnetoelectric properties and the θ parameter yield film opacity and polarization properties which could be interesting in the case of topological insulators, among other topological systems.

  18. Photographic film image enhancement

    NASA Technical Reports Server (NTRS)

    Horner, J. L.

    1975-01-01

    A series of experiments were undertaken to assess the feasibility of defogging color film by the techniques of optical spatial filtering. A coherent optical processor was built using red, blue, and green laser light input and specially designed Fourier transformation lenses. An array of spatial filters was fabricated on black and white emulsion slides using the coherent optical processor. The technique was first applied to laboratory white light fogged film, and the results were successful. However, when the same technique was applied to some original Apollo X radiation fogged color negatives, the results showed no similar restoration. Examples of each experiment are presented and possible reasons for the lack of restoration in the Apollo films are discussed.

  19. Thin film temperature sensor

    NASA Technical Reports Server (NTRS)

    Grant, H. P.; Przybyszewski, J. S.

    1980-01-01

    Thin film surface temperature sensors were developed. The sensors were made of platinum-platinum/10 percent rhodium thermocouples with associated thin film-to-lead wire connections and sputtered on aluminum oxide coated simulated turbine blades for testing. Tests included exposure to vibration, low velocity hydrocarbon hot gas flow to 1250 K, and furnace calibrations. Thermal electromotive force was typically two percent below standard type S thermocouples. Mean time to failure was 42 hours at a hot gas flow temperature of 1250 K and an average of 15 cycles to room temperature. Failures were mainly due to separation of the platinum thin film from the aluminum oxide surface. Several techniques to improve the adhesion of the platinum are discussed.

  20. The Nuclear Debate in Film

    ERIC Educational Resources Information Center

    Dowling, John

    1977-01-01

    Provides a nuclear film bibliography grouped into the areas of: building and using the bomb; living with the bomb; and living with nuclear power. These films are for mature high school students and older. (MLH)

  1. Thin film solar cell workshop

    NASA Technical Reports Server (NTRS)

    Armstrong, Joe; Jeffrey, Frank

    1993-01-01

    A summation of responses to questions posed to the thin-film solar cell workshop and the ensuing discussion is provided. Participants in the workshop included photovoltaic manufacturers (both thin film and crystalline), cell performance investigators, and consumers.

  2. Thin films for material engineering

    NASA Astrophysics Data System (ADS)

    Wasa, Kiyotaka

    2016-07-01

    Thin films are defined as two-dimensional materials formed by condensing one by one atomic/molecular/ionic species of matter in contrast to bulk three-dimensional sintered ceramics. They are grown through atomic collisional chemical reaction on a substrate surface. Thin film growth processes are fascinating for developing innovative exotic materials. On the basis of my long research on sputtering deposition, this paper firstly describes the kinetic energy effect of sputtered adatoms on thin film growth and discusses on a possibility of room-temperature growth of cubic diamond crystallites and the perovskite thin films of binary compound PbTiO3. Secondly, high-performance sputtered ferroelectric thin films with extraordinary excellent crystallinity compatible with MBE deposited thin films are described in relation to a possible application for thin-film MEMS. Finally, the present thin-film technologies are discussed in terms of a future material science and engineering.

  3. Current Film Periodicals in English. Revised Edition.

    ERIC Educational Resources Information Center

    Reilly, Adam, Comp.

    This bibliography of about 200 periodicals dealing with film covers several types of magazine: scholarly journals on film aesthetics, like "The Film Journal"; news notes for movie fans, like "Film Nut News"; magazines which cover films as well as the other arts, like "Cue" and "After Dark"; film education periodicals, like "Media and Methods";…

  4. Biomimetic thin film deposition

    NASA Astrophysics Data System (ADS)

    Rieke, P. C.; Campbell, A. A.; Tarasevich, B. J.; Fryxell, G. E.; Bentjen, S. B.

    1991-04-01

    Surfaces derivatized with organic functional groups were used to promote the deposition of thin films of inorganic minerals. These derivatized surfaces were designed to mimic the nucleation proteins that control mineral deposition during formation of bone, shell, and other hard tissues in living organisms. By the use of derivatized substrates control was obtained over the phase of mineral deposited, the orientation of the crystal lattice and the location of deposition. These features are of considerable importance in many technically important thin films, coatings, and composite materials. Methods of derivatizing surfaces are considered and examples of controlled mineral deposition are presented.

  5. Superconducting Electronic Film Structures

    DTIC Science & Technology

    1991-02-14

    superconductors, yttrium , barium, copper, oxides, high, critical, temperature, thin films, tunneling, barriers, thallium, sputtering. 19. ABSTRACT (Continue on...50*C lower than that required for YBCO. In common with YBCO, the best films grew epitaxially with a c-axis orientation on SrTiO3 , LaAIO 3, and NdGaO 3...for c-axis growth were (001) faces of LaAIO 3, NdGaO 3 , SrTiO3 , MgO. yttria-stabilized ZrO2 (YSZ), 11 and (1102) sapphire. Low substrate

  6. Thin film photovoltaic device

    DOEpatents

    Catalano, Anthony W.; Bhushan, Manjul

    1982-01-01

    A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids.

  7. Thin film ceramic thermocouples

    NASA Technical Reports Server (NTRS)

    Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)

    2011-01-01

    A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

  8. Thin Film Phosphor Development

    DTIC Science & Technology

    1989-01-01

    followed in Fig. 1. Two different garnet phases are observed in the fired films. The "low temperature " phase observed in the film treated at 9(X)°C has a... garnets ,1 121 thle experimentall~v-ob,•crved lattice constar.als correspond to the followving lmh composition for the low and high temperature phases...deposited, which is probably an yttrium rich garnet (see Figure 1). At I100)°C we start to see the appearance of both phases. As the firing temperature

  9. NMR characterization of thin films

    DOEpatents

    Gerald II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2010-06-15

    A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

  10. VACUUM DEPOSITION OF THIN FILMS,

    DTIC Science & Technology

    The book deals with methods of obtaining and processing thin films , methods of measuring the deposition rate and thickness of thin-film layers, and...the main fields of application of thin films . Vacuum requirements and the requirements for the composition of the residual medium in thermal...evaporation and cathode sputtering are given, and modern methods of producing and measuring vacuums and the equipment used in obtaining thin films are described. (Author)

  11. Center for Thin Film Studies

    DTIC Science & Technology

    1991-01-22

    techniques for reducing roughness were developed and tested . Substrate Preparation We deposited Si films by sputtering on a variety of substrates, and...deposition," Mod. Phys. Lett. B 3, 1039 (1989). 41 42 Nd: YAG LASER ABLATION OF BaTiO 3 THIN FILMS *URSULA J. GIBSON, **J.A. RUFFNER,***J.J. MCNALLY...thin films of barium titanate onto a variety of substrates, using picosecond and nanosecond pulsed Nd: YAG lasers. The films were deposited from a hot

  12. Teaching Argumentative Writing through Film.

    ERIC Educational Resources Information Center

    Fluitt-Dupuy, Jan

    2001-01-01

    Discusses how watching and discussing feature films and writing reviews of these films in the English-as-a-Second/Foreign-Language classroom can be instrumental in teaching the principles of good argumentative writing within the confines of the simple movie review. Six steps for teaching a film review unit are provided. (Author/VWL)

  13. Longevity Of Dry Film Lubricants

    NASA Technical Reports Server (NTRS)

    Kannel, J. W.; Stockwell, R. D.

    1993-01-01

    Report describes evaluation of dry film lubricants candidate for use in rotary joints of proposed Space Station. Study included experiments and theoretical analyses focused on longevity of sputtered molybdenum disulfide films and ion-plated lead films under conditions partially simulating rolling contact.

  14. Coated Aluminized Film Resists Corrosion

    NASA Technical Reports Server (NTRS)

    Rockoff, H. J.

    1982-01-01

    Commercially available corrosion-protection coating allows less costly metals - aluminum in particular used in heat-reflecting films for thermal barriers. Previously, such films had to incorporate gold as reflective layer to withstand humidity, moisture, and salt spray without corroding. This protective coating prevents corrosion of metalized films during evironmental exposure yet remains flexible, thermally stable and clear.

  15. Radical Pedagogy, Prison, and Film

    ERIC Educational Resources Information Center

    O'Neill, Dierdre

    2015-01-01

    This article explores the work of The Inside Film project. Inside Film works with a specific group of people (prisoners and ex-prisoners) in a particular set of circumstances (in prison or on parole) exploring how film making can be used within prison education or with people who have been to prison as a means of fostering a critical engagement…

  16. Analysis of Film as Communication.

    ERIC Educational Resources Information Center

    Stupp, Vicki O'Donnell

    Films function as a persuasive process in that they bring about a reinforcement or change in attitude, belief, or behavior by producing a cognitive restructuring of the audience's frame of reference. Organized research into the effects of films falls into two categories: macro-media studies exploring the way films reflect the psychological…

  17. Polyheterocycle Langmuir-Blodgett Films

    DTIC Science & Technology

    1989-05-29

    3-alkyl thiophene) and Stearic acid LB films. Thc oricntation of single- and Multi-laycr films on platinum substrates have bccn studicd by Ncar Edgc...not surface active. The LB films were obtained by spreading a mixture of the poly(3-alkvl thiophenes) and stearic acid (C,71-5 COOH ) onto the water

  18. Making Diamondlike Films More Transparent

    NASA Technical Reports Server (NTRS)

    Mirtich, Michael J.; Kussmaul, Michael T.; Sovey, James S.; Banks, Bruce A.

    1994-01-01

    Diamondlike carbon films highly transparent to visible light made by dual-ion-beam deposition process. Hard, resistant to scratching, and hermetic. Used as protective coatings on eyeglasses, magnetic recording heads, computer hard disks, and windows in bar-code scanners. Amorphous diamondlike carbon films preferable to polycrystalline diamond films in these and other applications. Smooth and adherent and deposited at room temperature.

  19. Methods for producing complex films, and films produced thereby

    DOEpatents

    Duty, Chad E.; Bennett, Charlee J. C.; Moon, Ji -Won; Phelps, Tommy J.; Blue, Craig A.; Dai, Quanqin; Hu, Michael Z.; Ivanov, Ilia N.; Jellison, Jr., Gerald E.; Love, Lonnie J.; Ott, Ronald D.; Parish, Chad M.; Walker, Steven

    2015-11-24

    A method for producing a film, the method comprising melting a layer of precursor particles on a substrate until at least a portion of the melted particles are planarized and merged to produce the film. The invention is also directed to a method for producing a photovoltaic film, the method comprising depositing particles having a photovoltaic or other property onto a substrate, and affixing the particles to the substrate, wherein the particles may or may not be subsequently melted. Also described herein are films produced by these methods, methods for producing a patterned film on a substrate, and methods for producing a multilayer structure.

  20. A Film Canister Colorimeter.

    ERIC Educational Resources Information Center

    Gordon, James; James, Alan; Harman, Stephanie; Weiss, Kristen

    2002-01-01

    A low-cost, low-tech colorimeter was constructed from a film canister. The student-constructed colorimeter was used to show the Beer-Lambert relationship between absorbance and concentration and to calculate the value of the molar absorptivity for permanganate at the wavelength emission maximum for an LED. Makes comparisons between this instrument…

  1. Rating Films on TV.

    ERIC Educational Resources Information Center

    Herman, Ginette; Leyens, Jacques-Philippe

    1977-01-01

    An analysis of the film viewing habits of Belgian television viewers reveals that movies with advisories regarding sex and violence are watched more than the movies without them. However, movies with qualifications tend to be judged less interesting than movies without qualifications. (JMF)

  2. Surrealism and Film.

    ERIC Educational Resources Information Center

    Matthews, J. H.

    This book is a critical, genre study of surrealist films including a general discussion of the backgrounds, influences, and overall traits of surrealism as a mode of artistic response to an absurdist world. Citing the impetus of Jacques Vache and Andre Breton as the originators of surrealism, the work expands upon the themes of fractured realism…

  3. Paradoxes in Film Ratings

    ERIC Educational Resources Information Center

    Moore, Thomas L.

    2006-01-01

    The author selected a simple random sample of 100 movies from the "Movie and Video Guide" (1996), by Leonard Maltin. The author's intent was to obtain some basic information on the population of roughly 19,000 movies through a small sample. The "Movie and Video Guide" by Leonard Maltin is an annual ratings guide to movies. While not all films ever…

  4. Film as Composition.

    ERIC Educational Resources Information Center

    Costanzo, William

    1986-01-01

    Describes the development of a freshman English program based on the analogy of film as composition and discusses implications of this program for other teachers of writing at a time when television and movies are giving unprecedented competition to the printed page for students' attention. (HTH)

  5. Films in Depth.

    ERIC Educational Resources Information Center

    Schrievogel, Paul A.; Prete, Anthony T.

    Bound in a slipcover rather than in signatures, this "book" is made up of thirteen separately bound booklets. The first booklet is an introduction to the use of film in the classroom both in teaching the filmic art and in increasing the visual literacy of students on the high school and early college levels. The twelve other booklets each treat a…

  6. Protein thin film machines.

    PubMed

    Federici, Stefania; Oliviero, Giulio; Hamad-Schifferli, Kimberly; Bergese, Paolo

    2010-12-01

    We report the first example of microcantilever beams that are reversibly driven by protein thin film machines fueled by cycling the salt concentration of the surrounding solution. We also show that upon the same salinity stimulus the drive can be completely reversed in its direction by introducing a surface coating ligand. Experimental results are throughout discussed within a general yet simple thermodynamic model.

  7. Films on Deafness.

    ERIC Educational Resources Information Center

    Parlato, Salvatore J., Jr., Comp.

    This filmography on deafness, which contains summaries of 192 16mm films arranged in alphabetical order by title, covers a wide variety of topics as evidenced by the categorical title index: communication, the nature of deafness, detection and measurement of deafness, education and training, multi-handicaps, and noise pollution. Running time, date…

  8. Intercultural Training with Films

    ERIC Educational Resources Information Center

    Roell, Christine

    2010-01-01

    Films are a great medium to use not only to practice English, but also to facilitate intercultural learning. Today English is a global language spoken by people from many countries and cultural backgrounds. Since culture greatly impacts communication, it is helpful for teachers to introduce lessons and activities that reveal how different…

  9. Balloon film strain measurement

    NASA Astrophysics Data System (ADS)

    Rand, James L.

    In order to understand the state of stress in scientific balloons, a need exists for the measurement of film deformation in flight. The results of a flight test program are reported where material strain was measured for the first time during the inflation, launch, ascent and float of a typical natural shape, zero pressure scientific balloon.

  10. Introduction to Film.

    ERIC Educational Resources Information Center

    Burns, Gary

    There are numerous ways to structure the introduction to film course so as to meet the needs of the different types of students who typically enroll. Assuming there is no production component in the course, the teacher is left with two major approaches to choose from--historical and aesthetic. The units in the course will typically be built around…

  11. Diamond films: Historical perspective

    SciTech Connect

    Messier, R.

    1993-01-01

    This section is a compilation of notes and published international articles about the development of methods of depositing diamond films. Vapor deposition articles are included from American, Russian, and Japanese publications. The international competition to develop new deposition methodologies is stressed. The current status of chemical vapor deposition of diamond is assessed.

  12. Thin film photovoltaic cell

    DOEpatents

    Meakin, John D.; Bragagnolo, Julio

    1982-01-01

    A thin film photovoltaic cell having a transparent electrical contact and an opaque electrical contact with a pair of semiconductors therebetween includes utilizing one of the electrical contacts as a substrate and wherein the inner surface thereof is modified by microroughening while being macro-planar.

  13. Film: The Creative Eye.

    ERIC Educational Resources Information Center

    Sohn, David A.

    Short films are often experimental in nature. They can place aspects of the environment which are usually unnoticed in such a way as to sharpen our observations of the world, and "create a new awareness, a fuller sense of life and being." Based on the premise that visual literacy is becoming increasingly important, this book describes several…

  14. Film, Radio, and Television.

    ERIC Educational Resources Information Center

    Hardesty, Carolyn, Ed.

    1990-01-01

    This journal issue covers the history of film, radio, and television in Iowa. The first article, "When Pictures and Sound Came to Iowa," summarizes the origin of movies and radio and their early beginnings in Iowa. Using old photographs and measurement charts, the viewing, reading, and listening habits of young people in 1950 and 1958…

  15. Films: 1971/72 Catalog of Films, Film Loops and Filmstrips for Schools, Colleges and Libraries.

    ERIC Educational Resources Information Center

    Learning Corp. of America, New York, NY.

    The films in this catalog are available for sale or rent from Learning Corporation of America. For elementary grades, films are available for use in the language arts and social studies classes. For junior and senior high, college, and adult courses, films are listed for instruction in art, music, and dance; environmental studies; United States…

  16. Colorless, Transparent, Aromatic Polyimide Films

    NASA Technical Reports Server (NTRS)

    St. Clair, A. K.; St. Clair, T. L.; Ezzell, K. S.; Ely, R. M.

    1986-01-01

    New process yields aromatic condensation polyimide films essentially colorless. Films between 90- and 100-percent transparent at visible wavelength of 500 nm. Optically transparent polyimide films made from variety of aromatic condensation polyimides. Range from very pale in color to colorless, compared to bright yellow color of conventional/ commercial aromatic polyimide film. Increased transparency achieved at no sacrifice in thermal stability, flexibility, toughness, or mechanical properties. These features extremely attractive as films or coating materials for aerospace applications or for any other applications where high optical transparency or thermal stability is required.

  17. Orientation filtering for crystalline films

    DOEpatents

    Smith, Henry I.; Atwater, Harry A.; Thompson, Carl V.; Geis, Michael W.

    1986-12-30

    A substrate is coated with a film to be recrystallized. A pattern of crystallization barriers is created in the film, for example, by etching voids in the film. An encapsulation layer is generally applied to protect the film, fill the voids and otherwise enhance a recrystallization process. Recrystallization is carried out such that certain orientations pass preferentially through the barrier, generally as a result of growth-velocity anisotropy. The result is a film of a specific predetermined crystallographic orientation, a range of orientations or a set of discrete orientations.

  18. Orientation filtering for crystalline films

    DOEpatents

    Smith, H.I.; Atwater, H.A.; Thompson, C.V.; Geis, M.W.

    1986-12-30

    A substrate is coated with a film to be recrystallized. A pattern of crystallization barriers is created in the film, for example, by etching voids in the film. An encapsulation layer is generally applied to protect the film, fill the voids and otherwise enhance a recrystallization process. Recrystallization is carried out such that certain orientations pass preferentially through the barrier, generally as a result of growth-velocity anisotropy. The result is a film of a specific predetermined crystallographic orientation, a range of orientations or a set of discrete orientations. 7 figs.

  19. Thin-film optical initiator

    DOEpatents

    Erickson, Kenneth L.

    2001-01-01

    A thin-film optical initiator having an inert, transparent substrate, a reactive thin film, which can be either an explosive or a pyrotechnic, and a reflective thin film. The resultant thin-film optical initiator system also comprises a fiber-optic cable connected to a low-energy laser source, an output charge, and an initiator housing. The reactive thin film, which may contain very thin embedded layers or be a co-deposit of a light-absorbing material such as carbon, absorbs the incident laser light, is volumetrically heated, and explodes against the output charge, imparting about 5 to 20 times more energy than in the incident laser pulse.

  20. Process to form mesostructured films

    DOEpatents

    Brinker, C. Jeffrey; Anderson, Mark T.; Ganguli, Rahul; Lu, Yunfeng

    1999-01-01

    This invention comprises a method to form a family of supported films film with pore size in the approximate range 0.8-20 nm exhibiting highly ordered microstructures and porosity derived from an ordered micellar or liquid-crystalline organic-inorganic precursor structure that forms during film deposition. Optically transparent, 100-500-nm thick films exhibiting a unique range of microstructures and uni-modal pore sizes are formed in seconds in a continuous coating operation. Applications of these films include sensors, membranes, low dielectric constant interlayers, anti-reflective coatings, and optical hosts.

  1. Method for making carbon films

    DOEpatents

    Tan, M.X.

    1999-07-29

    A method for treating an organic polymer material, preferably a vinylidene chloride/vinyl chloride copolymer (Saran) to produce a flat sheet of carbon film material having a high surface area ([approx equal]1000 m[sup 2] /g) suitable as an electrode material for super capacitor applications. The method comprises heating a vinylidene chloride/vinyl chloride copolymer film disposed between two spaced apart graphite or ceramic plates to a first temperature of about 160 C for about 14 hours to form a stabilized vinylidene chloride/vinyl chloride polymer film, thereafter heating the stabilized film to a second temperature of about 750 C in an inert atmosphere for about one hour to form a carbon film; and finally activating the carbon film to increase the surface area by heating the carbon film in an oxidizing atmosphere to a temperature of at least 750--850 C for between 1--6 hours. 2 figs.

  2. Method for making carbon films

    DOEpatents

    Tan, Ming X.

    1999-01-01

    A method for treating an organic polymer material, preferably a vinylidene chloride/vinyl chloride copolymer (Saran) to produce a flat sheet of carbon film material having a high surface area (.apprxeq.1000 m.sup.2 /g) suitable as an electrode material for super capacitor applications. The method comprises heating a vinylidene chloride/vinyl chloride copolymer film disposed between two spaced apart graphite or ceramic plates to a first temperature of about 160.degree. C. for about 14 hours to form a stabilized vinylidene chloride/vinyl chloride polymer film, thereafter heating the stabilized film to a second temperature of about 750.degree. C. in an inert atmosphere for about one hour to form a carbon film; and finally activating the carbon film to increase the surface area by heating the carbon film in an oxidizing atmosphere to a temperature of at least 750-850.degree. C. for between 1-6 hours.

  3. Professor Camillo Negro's Neuropathological Films.

    PubMed

    Chiò, Adriano; Gianetto, Claudia; Dagna, Stella

    2016-01-01

    Camillo Negro, Professor in Neurology at the University of Torino, was a pioneer of scientific film. From 1906 to 1908, with the help of his assistant Giuseppe Roasenda and in collaboration with Roberto Omegna, one of the most experienced cinematographers in Italy, he filmed some of his patients for scientific and educational purposes. During the war years, he continued his scientific film project at the Military Hospital in Torino, filming shell-shocked soldiers. In autumn 2011, the Museo Nazionale del Cinema, in partnership with the Faculty of Neurosciences of the University of Torino, presented a new critical edition of the neuropathological films directed by Negro. The Museum's collection also includes 16 mm footage probably filmed in 1930 by Doctor Fedele Negro, Camillo's son. One of these films is devoted to celebrating the effects of the so-called "Bulgarian cure" on Parkinson's disease.

  4. Thin film superconductor magnetic bearings

    DOEpatents

    Weinberger, Bernard R.

    1995-12-26

    A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.

  5. Lonsdaleite Films with Nanometer Thickness.

    PubMed

    Kvashnin, Alexander G; Sorokin, Pavel B

    2014-02-06

    We investigate the properties of potentially the stiffest quasi-2-D films with lonsdaleite structure. Using a combination of ab initio and empirical potential approaches, we analyze the elastic properties of lonsdaleite films in both elastic and inelastic regimes and compare them with graphene and diamond films. We review possible fabrication methods of lonsdaleite films using the pure nanoscale "bottom-up" paradigm: by connecting carbon layers in multilayered graphene. We propose the realization of this method in two ways: by applying direct pressure and by using the recently proposed chemically induced phase transition. For both cases, we construct the phase diagrams depending on temperature, pressure, and film thickness. Finally, we consider the electronic properties of lonsdaleite films and establish the nonlinear dependence of the band gap on the films' thicknesses and their lower effective masses in comparison with bulk crystal.

  6. Combustion effects on film cooling

    NASA Technical Reports Server (NTRS)

    Rousar, D. C.; Ewen, R. L.

    1977-01-01

    The effects of: (1) a reactive environment on film cooling effectiveness, and (2) film cooling on rocket engine performance were determined experimentally in a rocket thrust chamber assembly operating with hydrogen and oxygen propellants at 300 psi chamber pressure. Tests were conducted using hydrogen, helium, and nitrogen film coolants in an instrumented, thin walled, steel thrust chamber. The film cooling, performance loss, and heat transfer coefficient data were correlated with the ALRC entrainment film cooling model which relates film coolant effectiveness and mixture ratio at the wall to the amount of mainstream gases entrained with the film coolant in a mixing layer. In addition, a comprehensive thermal analysis computer program, HOCOOL, was prepared from previously existing ALRC computer programs and analytical techniques.

  7. Host thin films incorporating nanoparticles

    NASA Astrophysics Data System (ADS)

    Qureshi, Uzma

    The focus of this research project was the investigation of the functional properties of thin films that incorporate a secondary nanoparticulate phase. In particular to assess if the secondary nanoparticulate material enhanced a functional property of the coating on glass. In order to achieve this, new thin film deposition methods were developed, namely use of nanopowder precursors, an aerosol assisted transport technique and an aerosol into atmospheric pressure chemical vapour deposition system. Aerosol assisted chemical vapour deposition (AACVD) was used to deposit 8 series of thin films on glass. Five different nanoparticles silver, gold, ceria, tungsten oxide and zinc oxide were tested and shown to successfully deposit thin films incorporating nanoparticles within a host matrix. Silver nanoparticles were synthesised and doped within a titania film by AACVD. This improved solar control properties. A unique aerosol assisted chemical vapour deposition (AACVD) into atmospheric pressure chemical vapour deposition (APCVD) system was used to deposit films of Au nanoparticles and thin films of gold nanoparticles incorporated within a host titania matrix. Incorporation of high refractive index contrast metal oxide particles within a host film altered the film colour. The key goal was to test the potential of nanopowder forms and transfer the suspended nanopowder via an aerosol to a substrate in order to deposit a thin film. Discrete tungsten oxide nanoparticles or ceria nanoparticles within a titanium dioxide thin film enhanced the self-cleaning and photo-induced super-hydrophilicity. The nanopowder precursor study was extended by deposition of zinc oxide thin films incorporating Au nanoparticles and also ZnO films deposited from a ZnO nanopowder precursor. Incorporation of Au nanoparticles within a VO: host matrix improved the thermochromic response, optical and colour properties. Composite VC/TiC and Au nanoparticle/V02/Ti02 thin films displayed three useful

  8. Role of point defects/defect complexes in silicon device processing. Book of abstracts, fourth workshop

    SciTech Connect

    Not Available

    1994-06-01

    The 41 abstracts are arranged into 6 sessions: impurities and defects in commercial substrates: their sources, effects on material yield, and material quality; impurity gettering in silicon: limits and manufacturability of impurity gettering and in silicon solar cells; impurity/defect passivation; new concepts in silicon growth: improved initial quality and thin films; and silicon solar cell design opportunities.

  9. Rupture of vertical soap films

    NASA Astrophysics Data System (ADS)

    Rio, Emmanuelle

    2014-11-01

    Soap films are ephemeral and fragile objects. They tend to thin under gravity, which gives rise to the fascinating variations of colors at their interfaces but leads systematically to rupture. Even a child can create, manipulate and admire soap films and bubbles. Nevertheless, the reason why it suddenly bursts remains a mystery although the soap chosen to stabilize the film as well as the humidity of the air seem very important. One difficulty to study the rupture of vertical soap films is to control the initial solution. To avoid this problem we choose to study the rupture during the generation of the film at a controlled velocity. We have built an experiment, in which we measure the maximum length of the film together with its lifetime. The generation of the film is due to the presence of a gradient of surface concentration of surfactants at the liquid/air interface. This leads to a Marangoni force directed toward the top of the film. The film is expected to burst only when its weight is not balanced anymore by this force. We will show that this leads to the surprising result that the thicker films have shorter lifetimes than the thinner ones. It is thus the ability of the interface to sustain a surface concentration gradient of surfactants which controls its stability.

  10. Molecular films associated with LDEF

    NASA Technical Reports Server (NTRS)

    Crutcher, E. R.; Warner, K. J.

    1992-01-01

    The molecular films deposited on the surface of the Long Duration Exposure Facility (LDEF) originated from the paints and room-temperature-vulcanized (RTV) silicone materials intentionally used on the satellite and not from residual contaminants. The high silicone content of most of the films and the uniformity of the films indicates a homogenization process in the molecular deposition and suggests a chemically most favored composition for the final film. The deposition on interior surfaces and vents indicated multiple bounce trajectories or repeated deposition-reemission cycles. Exterior surface deposits indicated a significant return flux. Ultraviolet light exposure was required to fix the deposited film as is indicated by the distribution of the films on interior surfaces and the thickness of films at the vent locations. Thermal conditions at the time of exposure to ultraviolet light seems to be an important factor in the thickness of the deposit. Sunrise facing (ram direction) surfaces always had the thicker film. These were the coldest surfaces at the time of their exposure to ultraviolet light. The films have a layered structure suggesting cyclic deposition. As many as 34 distinct layers were seen in the films. The cyclic nature of the deposition and the chemical uniformity of the film one layer to the next suggest an early deposition of the films though there is evidence for the deposition of molecular films throughout the nearly six year exposure of the satellite. A final 'spray' of an organic material associated with water soluble salts occurred very late in the mission. This may have been the result of one of the shuttle dump activities.

  11. Advanced thin film thermocouples

    NASA Technical Reports Server (NTRS)

    Kreider, K. G.; Semancik, S.; Olson, C.

    1984-01-01

    The fabrication, materials characterization, and performance of thin film platinum rhodium thermocouples on gas turbine alloys was investigated. The materials chosen for the study were the turbine blade alloy systems MAR M200+Hf with NiCoCrAlY and FeCrAlY coatings, and vane alloy systems MAR M509 with FeCrAlY. Research was focussed on making improvements in the problem areas of coating substrate stability, adhesion, and insulation reliability and durability. Diffusion profiles between the substrate and coating with and without barrier coatings of Al2O3 are reported. The relationships between fabrication parameters of thermal oxidation and sputtering of the insulator and its characterization and performance are described. The best thin film thermocouples were fabricated with the NiCoCrAlY coatings which were thermally oxidized and sputter coated with Al2O3.

  12. Magnetoresistance of Au films

    SciTech Connect

    Zhang, D. L. Song, X. H.; Zhang, X.; Zhang, X.-G.

    2014-12-14

    Classical magnetoresistance (MR) in nonmagnetic metals are conventionally understood in terms of the Kohler rule, with violation usually viewed as anomalous electron transport, in particular, as evidence of non-Fermi liquid behavior. Measurement of the MR of Au films as a function of temperature and film thickness reveals a strong dependence on grain size distribution and clear violation of the Kohler rule. Using a model of random resistor network, we show that this result can be explained if the MR arises entirely from inhomogeneity due to grain boundary scattering and thermal activation of grain boundary atoms. Consequently, the Kohler rule should not be used to distinguish normal and anomalous electron transport in solids.

  13. Falling film evaporator

    DOEpatents

    Bruns, Lester E.

    1976-01-01

    A falling film evaporator including a vertically oriented pipe heated exteriorly by a steam jacket and interiorly by a finned steam tube, all heating surfaces of the pipe and steam tube being formed of a material wet by water such as stainless steel, and packing within the pipe consisting of Raschig rings formed of a material that is not wet by water such as polyvinylidene fluoride.

  14. Thin film composite electrolyte

    DOEpatents

    Schucker, Robert C.

    2007-08-14

    The invention is a thin film composite solid (and a means for making such) suitable for use as an electrolyte, having a first layer of a dense, non-porous conductive material; a second layer of a porous ionic conductive material; and a third layer of a dense non-porous conductive material, wherein the second layer has a Coefficient of thermal expansion within 5% of the coefficient of thermal expansion of the first and third layers.

  15. Nonlinear optical thin films

    NASA Technical Reports Server (NTRS)

    Leslie, Thomas M.

    1993-01-01

    A focused approach to development and evaluation of organic polymer films for use in optoelectronics is presented. The issues and challenges that are addressed include: (1) material synthesis, purification, and the tailoring of the material properties; (2) deposition of uniform thin films by a variety of methods; (3) characterization of material physical properties (thermal, electrical, optical, and electro-optical); and (4) device fabrication and testing. Photonic materials, devices, and systems were identified as critical technology areas by the Department of Commerce and the Department of Defense. This approach offers strong integration of basic material issues through engineering applications by the development of materials that can be exploited as the active unit in a variety of polymeric thin film devices. Improved materials were developed with unprecedented purity and stability. The absorptive properties can be tailored and controlled to provide significant improvement in propagation losses and nonlinear performance. Furthermore, the materials were incorporated into polymers that are highly compatible with fabrication and patterning processes for integrated optical devices and circuits. By simultaneously addressing the issues of materials development and characterization, keeping device design and fabrication in mind, many obstacles were overcome for implementation of these polymeric materials and devices into systems. We intend to considerably improve the upper use temperature, poling stability, and compatibility with silicon based devices. The principal device application that was targeted is a linear electro-optic modulation etalon. Organic polymers need to be properly designed and coupled with existing integrated circuit technology to create new photonic devices for optical communication, image processing, other laser applications such as harmonic generation, and eventually optical computing. The progression from microscopic sample to a suitable film

  16. Waterborne Polymeric Films.

    DTIC Science & Technology

    1981-02-01

    Parameters of Test Fluids I " 3. Energies of Vaporization and Molar Volumes of Some Acrylic Monomers 29 4. Physical Properties of Synthetic Polymers 31 S...Physical Properties of Synthetic Acrylic Aqueous Dispersions 33 6. Anionic Acrylic Clear-film Formulations 35 7 Fluid Resistance of Anionic Acrylic...41 11. Energeis of Vaporization and Molar Volumes of Some Polyurethanes 45 12. Solution Properties of Synthetic Polyurethanes 47 13. Aqueous

  17. Spring magnet films.

    SciTech Connect

    Bader, S. D.; Fullerton, E. E.; Gornakov, V. S.; Inomata, A.; Jiang, J. S.; Nikitenko, V. I.; Shapiro, A. J.; Shull, R. D.; Sowers, C. H.

    1999-03-29

    The properties of exchange-spring-coupled bilayer and superlattice films are highlighted for Sm-Co hard magnet and Fe or Co soft magnet layers. The hexagonal Sm-Co is grown via magnetron sputtering in a- and b-axis epitaxial orientations. In both cases the c-axis, in the film plane, is the easy axis of magnetization. Trends in coercivity with film thickness are established and related to the respective microstructure of the two orientations. The magnetization reversal process for the bilayers is examined by magnetometry and magneto-optical imaging, as well as by simulations that utilize a one-dimensional model to provide the spin configuration for each atomic layer. The Fe magnetization is pinned to that of the Sm-Co at the interface, and reversal proceeds via a progressive twisting of the Fe magnetization. The Fe demagnetization curves are reversible as expected for a spring magnet. Comparison of experiment and simulations indicates that the spring magnet behavior can be understood from the intrinsic properties of the hard and soft layers. Estimated are made of the ultimate gain in performance that can potentially be realized in this system.

  18. Effect of Repetitive Film Showings on Learning.

    ERIC Educational Resources Information Center

    Mc Tavish, C. L.

    In a study made in 1949 to determine the increment in learning that could be attributed to repetition, four general science films were shown to each of four groups of college students in such a way that each group saw one of the films once, a second film twice, a third film three times, and a fourth film four times. The experimental population…

  19. Short Films for Physics Teaching, A Catalog.

    ERIC Educational Resources Information Center

    Bluestone, Barbara Z.; Roth, Richard F.

    This annotated film catalog is a product of the Conference on Single Concept Films in College Physics Teaching sponsored by the Commission on College Physics. Both 8mm and 16mm single concept films are listed for physics and related disciplines. The catalog includes commercial, noncommercial, and foreign films. However, the film coverage was…

  20. Films on the arms race

    SciTech Connect

    Dowling, J.

    1983-01-01

    Films convey the historical perspectives, the biographical stories, the insights of the participants, and the horror of nuclear war - far better than can any physicist. While films are not very efficient for covering details, derivation, or numbers, they can not be beaten in showing what really happens in a nuclear explosion, in getting across general concepts, in illustrating the parameters of a problem, and the problem itself. Most importantly, films and TV can reach the people who must be informed about these issues if we are to resolve the problems. The author points out how films can contribute to an understanding of the issues of the arms race and nuclear war, with references to specific films. An annotated bibliography of 37 films is then presented.

  1. Elasticity of Flowing Soap films

    NASA Astrophysics Data System (ADS)

    Kim, Ildoo; Mandre, Shreyas

    2016-11-01

    The robustness of soap films and bubbles manifests their mechanical stability. The single most important factor underlying the mechanical stability of soap films is its elasticity. Non-destructive measurement of the elasticity in these films has been cumbersome, because of its flowing nature. Here we provide a convenient, reproducible, and non-destructive method for measuring the elasticity by generating and inspecting Marangoni waves. Our method is based on generating an oblique shock by inserting a thin cylindrical obstacle in the flowing film, and converting the measured the shock angle to elasticity. Using this method, we find a constant value for the elasticity of 22 dyne/cm in the commonly used range of film widths, thicknesses or flow rates, implying that the surface of the film is chemically saturated with soap molecules.

  2. Fracture characteristics of balloon films

    NASA Technical Reports Server (NTRS)

    Portanova, Marc A.

    1989-01-01

    An attempt was made to determine the failure modes of high altitude scientific balloons through an investigation of the fracture characteristics of the thin polyethylene films. Two films were the subject of the evaluation, Winzen Int.'s Stratafilm SF-85 and Raven Industries' Astro-E. Research began with an investigation of the film's cold brittleness point and it's effect on the ultimate strength and elasticity of the polyethylene film. A series of preliminary investigations were conducted to develop an understanding of the material characteristics. The primary focus of this investigation was on the notch sensitivity of the films. Simple stress strain tests were also conducted to enable analysis employing fracture toughness parameters. Studies were conducted on both film types at 23 C (room temperature), -60 C, -90 C, and -120 C.

  3. Characterization of Nanostructured Polymer Films

    DTIC Science & Technology

    2014-12-23

    of the film for complete polymer chain relaxation, including relaxation of surface features . The presence of intact surface globules at a substrate...AFRL-OSR-VA-TR-2015-0059 Characterization of Nanostructured Polymer Films RODNEY PRIESTLEY TRUSTEES OF PRINCETON UNIVERSITY Final Report 12/23/2014...Report 3. DATES COVERED (From - To) 06/01/2012-08/31/2014 4. TITLE AND SUBTITLE Characterization of Nanostructured Polymer Films 5a. CONTRACT

  4. Diamond films for laser hardening

    NASA Technical Reports Server (NTRS)

    Albin, S.; Watkins, L.; Ravi, K.; Yokota, S.

    1989-01-01

    Laser-damage experiments were performed on free-standing polycrystalline diamond films prepared by plasma-enhanced CVD. The high laser-induced stress resistance found for this material makes it useful for thin-film coatings for laser optics. Results for diamond-coated silicon substrates demonstrate the enhanced damage threshold imparted by diamond thin-film coatings to materials susceptible to laser damage.

  5. Frequency mixer having ferromagnetic film

    DOEpatents

    Khitun, Alexander; Roshchin, Igor V.; Galatsis, Kosmas; Bao, Mingqiang; Wang, Kang L.

    2016-03-29

    A frequency conversion device, which may include a radiofrequency (RF) mixer device, includes a substrate and a ferromagnetic film disposed over a surface of the substrate. An insulator is disposed over the ferromagnetic film and at least one microstrip antenna is disposed over the insulator. The ferromagnetic film provides a non-linear response to the frequency conversion device. The frequency conversion device may be used for signal mixing and amplification. The frequency conversion device may also be used in data encryption applications.

  6. Communicating Science: Lessons from Film.

    PubMed

    Berlin, Heather A

    2016-04-01

    Films engage us visually, aurally, viscerally, and emotionally. Incorporating science themes into films has the potential to open up new audiences to scientific ideas, pique their interests, and inspire them to engage in a broader discussion of the science itself. Here, I discuss several narrative techniques and strategies employed in film to effectively engage the audience around science themes, which may be useful tools for scientists looking to become better communicators.

  7. Drying of thin colloidal films

    NASA Astrophysics Data System (ADS)

    Routh, Alexander F.

    2013-04-01

    When thin films of colloidal fluids are dried, a range of transitions are observed and the final film profile is found to depend on the processes that occur during the drying step. This article describes the drying process, initially concentrating on the various transitions. Particles are seen to initially consolidate at the edge of a drying droplet, the so-called coffee-ring effect. Flow is seen to be from the centre of the drop towards the edge and a front of close-packed particles passes horizontally across the film. Just behind the particle front the now solid film often displays cracks and finally the film is observed to de-wet. These various transitions are explained, with particular reference to the capillary pressure which forms in the solidified region of the film. The reasons for cracking in thin films is explored as well as various methods to minimize its effect. Methods to obtain stratified coatings through a single application are considered for a one-dimensional drying problem and this is then extended to two-dimensional films. Different evaporative models are described, including the physical reason for enhanced evaporation at the edge of droplets. The various scenarios when evaporation is found to be uniform across a drying film are then explained. Finally different experimental techniques for examining the drying step are mentioned and the article ends with suggested areas that warrant further study.

  8. Slow rupture of polymer films

    NASA Astrophysics Data System (ADS)

    Kliakhandler, Igor

    2004-11-01

    Bursting of soap film is a fast and fascinating process. It turns out that certain polymer films rupture in a somewhat similar fashion, but much slower. The slowness of the process allows one to study the rupture of polymer films with details. The rupture process in Hele-Shaw-like fashion shows remarkable properties, and is a very simple system. It turns out that propagation speed of the rupture is a function of the film thickness, and rheologic properties of the polymer. Experimental results will be compared with theory, together with demonstration of the experiment.

  9. Evaluation of the Blood Film.

    PubMed

    Campbell, Terry W

    2015-09-01

    Evaluation of hemic cell morphology in stained blood film may be the most important part of the hematologic evaluation of exotic animals. The blood film provides important information regarding red blood cell abnormalities, such as changes in cell shape and color, presence of inclusions, and, in the case of lower vertebrates, changes in the position of the cell nucleus. Stained blood film also provides information about changes in leukocyte numbers and morphology, and shows important hemic features of mammalian platelets and the thrombocytes of lower vertebrates. The blood film is needed in the detection and identification of blood parasites.

  10. Oxide Films for RF Applications

    DTIC Science & Technology

    2008-07-01

    structured thin film superlattices of (AEO)m( TiO2 )n - type with varying m and n numbers in order to generate a homologous series of materials having...mechanisms in MBE oxide films The proposed goal was to identify, isolate, and reduce sources of loss in thin film dielectrics. It is important to note...that the loss in bulk single crystals is often orders of magnitude below that of their thin film counterparts. It is believed that defects in thin

  11. Process to form mesostructured films

    DOEpatents

    Brinker, C.J.; Anderson, M.T.; Ganguli, R.; Lu, Y.F.

    1999-01-12

    This invention comprises a method to form a family of supported films with pore size in the approximate range 0.8-20 nm exhibiting highly ordered microstructures and porosity derived from an ordered micellar or liquid-crystalline organic-inorganic precursor structure that forms during film deposition. Optically transparent, 100-500-nm thick films exhibiting a unique range of microstructures and uni-modal pore sizes are formed in seconds in a continuous coating operation. Applications of these films include sensors, membranes, low dielectric constant interlayers, anti-reflective coatings, and optical hosts. 12 figs.

  12. "Kuleshov on Film": A Spectator-Centered Film Theory.

    ERIC Educational Resources Information Center

    Curran, Trisha

    This paper describes some of the theories of cinematography of Soviet film theorist and filmmaker Lev Kuleshov. It points out that for him, film was communication portraying people's activities emanating from the environment. It explains that he was especially interested in audience response, particularly that of the proletariat, and that he felt…

  13. Electrically conductive palladium-containing polyimide films

    NASA Technical Reports Server (NTRS)

    St.clair, A. K.; Furtsch, T. A.; Taylor, L. T.

    1981-01-01

    Palladium addition makes light, flexible film with low resistivity to relieve space charging. Polyimide film is prepared in four steps: preparation of polyamic acid in polar solvent; addition of soluable palladium complex salt; fabrication of film of "palladium polyamic acid" solution; and thermal imidization of film to palladium-containing polyimide by 300 C heating. Lowered resistivities were achieved without loss in film flexibility or increase in film weight.

  14. Radiation grafting on natural films

    NASA Astrophysics Data System (ADS)

    Lacroix, M.; Khan, R.; Senna, M.; Sharmin, N.; Salmieri, S.; Safrany, A.

    2014-01-01

    Different methods of polymer grafting using gamma irradiation are reported in the present study for the preparation of newly functionalized biodegradable films, and some important properties related to their mechanical and barrier properties are described. Biodegradable films composed of zein and poly(vinyl alcohol) (PVA) were gamma-irradiated in presence of different ratios of acrylic acid (AAc) monomer for compatibilization purpose. Resulting grafted films (zein/PVA-g-AAc) had their puncture strength (PS=37-40 N mm-1) and puncture deformation (PD=6.5-9.8 mm) improved for 30% and 50% PVA in blend, with 5% AAc under 20 kGy. Methylcellulose (MC)-based films were irradiated in the presence of 2-hydroxyethyl methacrylate (HEMA) or silane, in order to determine the effect of monomer grafting on the mechanical properties of films. It was found that grafted films (MC-g-HEMA and MC-g-silane) using 35% monomer performed higher mechanical properties with PS values of 282-296 N mm-1 and PD of 5.0-5.5 mm under 10 kGy. Compatibilized polycaprolactone (PCL)/chitosan composites were developed via grafting silane in chitosan films. Resulting trilayer grafted composite film (PCL/chitosan-g-silane/PCL) presented superior tensile strength (TS=22 MPa) via possible improvement of interfacial adhesion (PCL/chitosan) when using 25% silane under 10 kGy. Finally, MC-based films containing crystalline nanocellulose (CNC) as a filling agent were prepared and irradiated in presence of trimethylolpropane trimethacrylate (TMPTMA) as a grafted plasticizer. Grafted films (MC-g-TMPTMA) presented superior mechanical properties with a TS of 47.9 MPa and a tensile modulus (TM) of 1792 MPa, possibly due to high yield formation of radicals to promote TMPTMA grafting during irradiation. The addition of CNC led to an additional improvement of the barrier properties, with a significant 25% reduction of water vapor permeability (WVP) of grafted films.

  15. Protective Film Moves Aside

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Relatively warmer daytime temperatures on Mars have allowed the biobarrier -- a shiny, protective film -- to peel away a little more from the robotic arm of NASA's Phoenix Mars Lander.

    This image shows the spacecraft's robotic arm in its stowed configuration, with the biobarrier unpeeled on landing day, or Sol (Martian day) 0, and the lander's first full day on Mars, Sol 1.

    The 'elbow' of the arm can be seen at the top center of the picture, and the biobarrier is the shiny film seen to the left of the arm.

    The biobarrier is an extra precaution to protect Mars from contamination with any bacteria from Earth. While the whole spacecraft was decontaminated through cleaning, filters and heat, the robotic arm was given additional protection because it is the only spacecraft part that will directly touch the ice below the surface of Mars.

    Before the arm was heated, it was sealed in the biobarrier, which is made of a trademarked film called Tedlar that holds up to baking like a turkey-basting bag. This ensures that any new bacterial spores that might have appeared during the final steps before launch and during the journey to Mars will not contact the robotic arm.

    After Phoenix landed, springs were used to pop back the barrier, giving it room to deploy.

    These images were taken on May 25, 2008 and May 26, 2008 by the spacecraft's Surface Stereo Imager.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  16. Plasma deposition of organic thin films: Control of film chemistry

    SciTech Connect

    Ratner, B.D.

    1993-12-31

    Plasma deposition of thin, polymeric films represent a versatile surface modification technology. Although these thin films are exploited for many applications, complaints heard about plasma deposited films are that their structures are uncharacterizable, that organic functionality is lost in their production and that reproducibility is difficult. Recently, new methods for film production, reactor control and surface characterization have led to well characterized plasma deposited thin polymeric films (PDTPF) with defined structure and organic functionality. Such PDTPF often closely resemble conventionally prepared homopolymers. Methods that can be used to control the chemistry of PDTPF are the minimization of the plasma power, pulsing the RF field to reduce the {open_quotes}plasma on{close_quotes} time, use of a Faraday cage to reduce electron bombardment, positioning the sample downfield from the glow zone, the use of monomers containing polymerizable double bonds and the use of a cold substrate to condense vapor simultaneously with plasma deposition.

  17. Antireflective polyimide based films

    NASA Astrophysics Data System (ADS)

    Cao, Yuanmei

    The goal of this work was to prepare antireflective and anti-abrasion films using polyimide and organically modified silica nanoparticle thin films. A series of thin film were prepared from colorless and soluble polyimide with organically modified silica colloids via a solution casting method. The polyimide was selected for its optical properties. Three type of organically modified silica nanoparticles were prepared by grafting polysiloxane, polyfluoroester and fluoroalkyl groups onto silica nanoparticles. The molecular weight of the polysiloxane, polyfluoroester and the amount of fluorinated alkyl groups were varied. The organically modified silica colloids were characterized by TEM, DLS, FTIR, 1H NMR, solid state 13C NMR and solid state 29Si NMR. The coatings were characterized by UV-Vis transmittance spectra and SEM. The effect of modified silica loading, the molecular weight of polymer and type of solvent on AR properties were studied. An enhancement in antireflective activity was observed for 1 wt% LPDMS modified (low molecular weight) silica coatings, 3 wt% fluorosilica-10 and 3% L-MPS-PF-SILICA nanoparticles (low molecular weight polyfluoroester modified silica) in dimethylacetamide (DMAc). In comparison with cyclopentanone (CPT), DMAc favors migration of silica particles towards coating-air interface giving higher transmittance. The migration of particles to the surface and consequent increased surface roughness were observed by SEM. The present study suggested a roll to roll solution casting method to create antireflective coatings. This approach had potential to be used for a one-step large-scale manufacturing of antireflective coating. Four acrylated bismaleimide were made via two-step process. The first step involved the solution imidization to form hydroxylated bismaleimide. In the second step, hydroxylated bismaleimide was reacted with acryloyl chloride to form acrylated bismaleimide. The acrylated bismaleimide were characterized by FTIR, 1H NMR, 13C

  18. Carbonaceous film coating

    DOEpatents

    Maya, Leon

    1989-01-01

    A method of making a carbonaceous film comprising heating tris(1,3,2-benzodiazaborolo)borazine or dodecahydro tris[1,3,2]diazaborine[1,2-a:1'2'-c:1"2"-e]borazine in an inert atmosphere in the presence of a substrate to a temperature at which the borazine compound decomposes, and the decomposition products deposit onto the substrate to form a thin, tenacious, highly reflective conductive coating having a narrow band gap which is susceptible of modification and a relatively low coefficient of friction.

  19. Thin film hydrogen sensor

    DOEpatents

    Lauf, Robert J.; Hoffheins, Barbara S.; Fleming, Pamela H.

    1994-01-01

    A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed.

  20. Cardiovascular Cine Film Quality

    NASA Astrophysics Data System (ADS)

    Scheid, Carl C.

    1983-12-01

    The detection of a cardiovascular stenosis involves the complex interaction of technique selection, system performance and anatomy. Technique selection for instance involves choosing the correct focal spot, pulse width, KVp, and frame rate for a given patient and projection angle. In order to provide guidance in this selection process, these variables were investigated in terms of their impact on image quality. Conclusions which were confirmed clinically are summarized in terms of recommended techniques for a range of patient sizes. The confirmation includes clinical films which demonstrates the effects of parameter changes.

  1. Carbonaceous film coating

    DOEpatents

    Maya, L.

    1988-04-27

    A method of making a carbonaceous film comprising heating tris(1,3,2-benzodiazaborolo)borazine or dodecahydro tris(1,3,2)diazaborine(1,2-a:1'2'-c:1''2''-e)borazine in an inert atmosphere in the presence of a substrate to a temperature at which the borazine compound decomposes, and the decomposition products deposit onto the substrate to form a thin, tenacious, highly reflective conductive coating having a narrow band gap which is susceptible of modification and a relatively low coefficient of friction.

  2. Turbine airfoil film cooling

    NASA Technical Reports Server (NTRS)

    Hylton, Larry D.

    1986-01-01

    Emphasis is placed on developing more accurate analytical models for predicting turbine airfoil external heat transfer rates. Performance goals of new engines require highly refined, accurate design tools to meet durability requirements. In order to obtain improvements in analytical capabilities, programs are required which focus on enhancing analytical techniques through verification of new models by comparison with relevant experimental data. The objectives of the current program are to develop an analytical approach, based on boundary layer theory, for predicting the effects of airfoil film cooling on downstream heat transfer rates and to verify the resulting analytical method by comparison of predictions with hot cascade data obtained under this program.

  3. High Performance YBCO Films

    DTIC Science & Technology

    1992-07-01

    growing high quality MgO films on SrF2 substrates is the oxygen partial pressure during the growth. The x-ray data presented in Fig. 13 indicates a...fluo-ide and quartz substrates. The best result with two buffer layers (MgO and YSZ) on SrF2 was an onset temperature (Tc) of 82K and a transition...With a YSZ buffer an onset temperature of 85K and a transition width of 5K was achieved. Recent success was demonstrated by Neocera ( under a NASA

  4. A Film Canister Colorimeter

    NASA Astrophysics Data System (ADS)

    Gordon, James; James, Alan; Harman, Stephanie; Weiss, Kristen

    2002-08-01

    A low-cost, low-tech colorimeter was constructed from a film canister. The light source and filter monochromator was an interchangeable LED. The detector for this system was a voltage-divider circuit composed of a photoresistor in series with a fixed resistor. The student-constructed colorimeter was used to show the Beer–Lambert relationship between absorbance and concentration and to calculate the value of the molar absorptivity for permanganate at the wavelength emission maximum for the LED. Comparisons were made between this instrument and three commercial spectrometers and colorimeters.

  5. Predicting film genres with implicit ideals.

    PubMed

    Olney, Andrew McGregor

    2012-01-01

    We present a new approach to defining film genre based on implicit ideals. When viewers rate the likability of a film, they indirectly express their ideal of what a film should be. Across six studies we investigate the category structure that emerges from likability ratings and the category structure that emerges from the features of film. We further compare these data-driven category structures with human annotated film genres. We conclude that film genres are structured more around ideals than around features of film. This finding lends experimental support to the notion that film genres are set of shifting, fuzzy, and highly contextualized psychological categories.

  6. Beryllium thin films for resistor applications

    NASA Technical Reports Server (NTRS)

    Fiet, O.

    1972-01-01

    Beryllium thin films have a protective oxidation resistant property at high temperature and high recrystallization temperature. However, the experimental film has very low temperature coefficient of resistance.

  7. Fire resistant films for aircraft applications

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.

    1983-01-01

    Alternative sandwich panel decorative films were investigated as replacements for the polyvinyl fluoride currently used in aircraft interiors. Candidate films were studied for flammability, smoke emission, toxic gas emission, flame spread, and suitability as a printing surface for the decorative acrylic ink system. Several of the candidate films tested were flame modified polyvinyl fluoride, polyvinylidene fluoride, polyimide, polyamide, polysulfone, polyphenylsulfone, polyethersulfone, polybenzimidazole, polycarbonate, polyparabanic acid, polyphosphazene, polyetheretherketon, and polyester. The films were evaluated as pure films only, films silk-screened with an acrylic ink, and films adhered to a phenolic fiberglass substrate. Films which exhibited the highest fire resistant properties included PEEK polyetheretherketon, Aramid polyamide, and ISO-BPE polyester.

  8. ADVANCED THIN-FILM SOLAR CELLS.

    DTIC Science & Technology

    SEMICONDUCTING FILMS), (* SOLAR CELLS , MANUFACTURING, GALLIUM ALLOYS, ARSENIC ALLOYS, PLATINUM, OXIDES, TRANSPORT PROPERTIES, MOLYBDENUM, METAL FILMS, COPPER, HYDROGEN, GERMANIUM ALLOYS, TIN ALLOYS, ZINC, CRYSTAL GROWTH.

  9. Liquid film demonstration experiment Skylab SL-4

    NASA Technical Reports Server (NTRS)

    Darbro, W.

    1975-01-01

    The liquid film demonstration experiment performed on Skylab 4 by Astronaut Gerald Carr, which involved the construction of water and soap films by boundary expansion and inertia, is discussed. Results include a 1-ml globule of water expanded into a 7-cm-diameter film as well as complex film structures produced by inertia whose lifetimes are longer in the low-g environment. Also discussed are 1-g acceleration experiments in which the unprovoked rupture of films was photographed and film lifetimes of stationary and rotated soap films were compared. Finally, there is a mathematical discussion regarding minimal surfaces, an isoperimetric problem, and liquid films.

  10. Predicting Film Genres with Implicit Ideals

    PubMed Central

    Olney, Andrew McGregor

    2013-01-01

    We present a new approach to defining film genre based on implicit ideals. When viewers rate the likability of a film, they indirectly express their ideal of what a film should be. Across six studies we investigate the category structure that emerges from likability ratings and the category structure that emerges from the features of film. We further compare these data-driven category structures with human annotated film genres. We conclude that film genres are structured more around ideals than around features of film. This finding lends experimental support to the notion that film genres are set of shifting, fuzzy, and highly contextualized psychological categories. PMID:23423823

  11. Electrical initiation of an energetic nanolaminate film

    DOEpatents

    Tringe, Joseph W.; Gash, Alexander E.; Barbee, Jr., Troy W.

    2010-03-30

    A heating apparatus comprising an energetic nanolaminate film that produces heat when initiated, a power source that provides an electric current, and a control that initiates the energetic nanolaminate film by directing the electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature. Also a method of heating comprising providing an energetic nanolaminate film that produces heat when initiated, and initiating the energetic nanolaminate film by directing an electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature.

  12. Cinemabilia; Catalogue of Film Literature.

    ERIC Educational Resources Information Center

    Cinemabilia, New York, NY.

    The catalog lists and briefly annotates more than 3,500 current, second-hand, and out-of-print books about film that are available from Cinemabilia, New York City. The catalog is divided into 37 categories. The section on special genre lists works on horror, science fiction, Westerns, and Tarzan films, ranging from "Drums of Fu-Manchu" to "Movie…

  13. Thin film ion conducting coating

    DOEpatents

    Goldner, Ronald B.; Haas, Terry; Wong, Kwok-Keung; Seward, George

    1989-01-01

    Durable thin film ion conducting coatings are formed on a transparent glass substrate by the controlled deposition of the mixed oxides of lithium:tantalum or lithium:niobium. The coatings provide durable ion transport sources for thin film solid state storage batteries and electrochromic energy conservation devices.

  14. Teaching the Holocaust through Film.

    ERIC Educational Resources Information Center

    Michalczyk, John J.

    The use of Holocaust-related films and Holocaust survivors as classroom resources is analyzed. The perspective and function of four film genres are outlined as follows. Newsreels, made by the Nazis to chronicle their "progress," provide powerful raw footage of the concentration camp experience. Documentaries, generally made by Allied…

  15. Improved Dielectric Films For Capacitors

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S.; Lewis, Carol R.; Cygan, Peter J.; Jow, T. Richard

    1994-01-01

    Dielectric films made from blends of some commercially available high-dielectric-constant cyanoresins with each other and with cellulose triacetate (CTA) have both high dielectric constants and high breakdown strengths. Dielectric constants as high as 16.2. Films used to produce high-energy-density capacitors.

  16. Latino Film and Video Images.

    ERIC Educational Resources Information Center

    Vazquez, Blanca, Ed.

    1990-01-01

    This theme issue of the "Centro Bulletin" examines media stereotypes of Latinos and presents examples of alternatives. "From Assimilation to Annihilation: Puerto Rican Images in U.S. Films" (R. Perez) traces the representation of Puerto Ricans from the early days of television to the films of the 1970s. "The Latino 'Boom'…

  17. Methods of Producing Thin Films,

    DTIC Science & Technology

    The report describes various methods of producing thin films , especially for microelectronics. In addition to the classical methods of forming thin ... films by vacuum vapor deposition, it also describes processes of diode sputtering and modern methods of cathode sputtering by means of a third

  18. Films for Sociology, First Edition.

    ERIC Educational Resources Information Center

    LeBeau, Bryan, Comp.

    This catalog contains a listing of over 1,000 16mm films of interest to students, teachers, and researchers in sociology. Whenever possible, content reflects current trends toward increased interdisciplinary investigation. In the main body of the catalog, the films are listed alphabetically by title. For each entry, information is given on…

  19. Liquid-film electron stripper

    DOEpatents

    Gavin, Basil F.

    1986-01-01

    An improved liquid-film electron stripper particularly for high intensity heavy ion beams which produces constant regenerated, stable, free-standing liquid films having an adjustable thickness between 0.3 to 0.05 microns. The improved electron stripper is basically composed of at least one high speed, rotating disc with a very sharp, precision-like, ground edge on one said of the disc's periphery and with a highly polished, flat, radial surface adjacent the sharp edge. A fine stream of liquid, such as oil, impinges at a 90.degree. angle adjacent the disc's sharp outer edge. Film terminators, located at a selected distance from the disc perimeter are positioned approximately perpendicular to the film. The terminators support, shape, and stretch the film and are arranged to assist in the prevention of liquid droplet formation by directing the collected film to a reservoir below without breaking or interfering with the film. One embodiment utilizes two rotating discs and associated terminators, with the discs rotating so as to form films in opposite directions, and with the second disc being located down beam-line relative to the first disc.

  20. The Thin Oil Film Equation

    NASA Technical Reports Server (NTRS)

    Brown, James L.; Naughton, Jonathan W.

    1999-01-01

    A thin film of oil on a surface responds primarily to the wall shear stress generated on that surface by a three-dimensional flow. The oil film is also subject to wall pressure gradients, surface tension effects and gravity. The partial differential equation governing the oil film flow is shown to be related to Burgers' equation. Analytical and numerical methods for solving the thin oil film equation are presented. A direct numerical solver is developed where the wall shear stress variation on the surface is known and which solves for the oil film thickness spatial and time variation on the surface. An inverse numerical solver is also developed where the oil film thickness spatial variation over the surface at two discrete times is known and which solves for the wall shear stress variation over the test surface. A One-Time-Level inverse solver is also demonstrated. The inverse numerical solver provides a mathematically rigorous basis for an improved form of a wall shear stress instrument suitable for application to complex three-dimensional flows. To demonstrate the complexity of flows for which these oil film methods are now suitable, extensive examination is accomplished for these analytical and numerical methods as applied to a thin oil film in the vicinity of a three-dimensional saddle of separation.

  1. Thin film atomic hydrogen detectors

    NASA Technical Reports Server (NTRS)

    Gruber, C. L.

    1977-01-01

    Thin film and bead thermistor atomic surface recombination hydrogen detectors were investigated both experimentally and theoretically. Devices were constructed on a thin Mylar film substrate. Using suitable Wheatstone bridge techniques sensitivities of 80 microvolts/2x10 to the 13th power atoms/sec are attainable with response time constants on the order of 5 seconds.

  2. Films in the ESL Classroom.

    ERIC Educational Resources Information Center

    Gex, Judith Coppock

    The most important consideration with regard to classroom use of films in an English as a second language (ESL) class is that it should be previewed by the teacher and selected according to criteria such as those suggested here. In example, short silent films that are uncluttered in appearance are good vehicles for teaching vocabulary. Some…

  3. Metal oxide films on metal

    DOEpatents

    Wu, Xin D.; Tiwari, Prabhat

    1995-01-01

    A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.

  4. Symbolism in the Feature Film.

    ERIC Educational Resources Information Center

    Bakony, Edward

    A study of symbolism in feature films reveals how the symbolism employed by film makers can serve as a bridge between feeling and thought, and between aesthetics and cognition. What individuals read from and learn through a symbol varies with what they bring to it. The filmmaker's symbolims must be universal and not private. However, symbolism in…

  5. Uses for Free Film Cans

    ERIC Educational Resources Information Center

    Batoff, Mitchell E.; Harmen, Jerry

    1973-01-01

    Describes multiple uses of empty film cans for equipping an elementary school science classroom. Instructional units in which film cans may be useful include buoyancy, mobiles, growing seeds, peas and particles, rocks and minerals, structures, field studies, sound, balancing, electricity, pedulums, chemical change, and optics, light, color. (PS)

  6. Magnetochromatic thin-film microplates.

    PubMed

    He, Le; Janner, Michael; Lu, Qipeng; Wang, Mingsheng; Ma, Hua; Yin, Yadong

    2015-01-07

    A new type of magnetochromatic material is developed based on thin-film interference of microplates self-assembled from super-paramagnetic nanocrystals. Dynamic optical tuning can be achieved through orientational manipulation of free-standing super-paramagnetic thin-film microplates using external magnetic fields.

  7. Thin Film Inorganic Electrochemical Systems.

    DTIC Science & Technology

    1995-07-01

    determined that thin film cathodes of LiCoO2 can be readily performed by either spray pyrolysis or spin coating . These cathodes are electrochemically...active. We have also determined that thin film anodes of Li4Ti5O12 can be prepared by spray pyrolysis or spin coating . These anodes are also

  8. Feminist Film Theory and Criticism.

    ERIC Educational Resources Information Center

    Mayne, Judith

    1985-01-01

    Discusses Laura Mulvey's 1975 essay, "Visual Pleasure and Narrative Cinema," and the ideas about feminist film theory and psychoanalysis as a critical tool which it raises. Suggests contradiction is the central issue in feminist film theory. Explores definitions of women's cinema. (SA)

  9. System for measuring film thickness

    DOEpatents

    Batishko, Charles R.; Kirihara, Leslie J.; Peters, Timothy J.; Rasmussen, Donald E.

    1990-01-01

    A system for determining the thicknesses of thin films of materials exhibiting fluorescence in response to exposure to excitation energy from a suitable source of such energy. A section of film is illuminated with a fixed level of excitation energy from a source such as an argon ion laser emitting blue-green light. The amount of fluorescent light produced by the film over a limited area within the section so illuminated is then measured using a detector such as a photomultiplier tube. Since the amount of fluorescent light produced is a function of the thicknesses of thin films, the thickness of a specific film can be determined by comparing the intensity of fluorescent light produced by this film with the intensity of light produced by similar films of known thicknesses in response to the same amount of excitation energy. The preferred embodiment of the invention uses fiber optic probes in measuring the thicknesses of oil films on the operational components of machinery which are ordinarily obscured from view.

  10. Films and the English Class.

    ERIC Educational Resources Information Center

    Donelson, Kenneth, Ed.

    1971-01-01

    The importance of film in the English classroom and its vitality in the English curriculum are discussed. Articles that comprise this issue of the bulletin are: The Trouble with Film Teaching by James E. Cutts; "You Ain't Heard Nothin' Yet" or Send Your Students to the Flicks Tonight by Bob Haskett; It's the Reel Thing: The Verite of Cinema Is…

  11. The Public Library Film Redefined.

    ERIC Educational Resources Information Center

    Peltier, Euclid

    1978-01-01

    An historical discussion of three types of film--teaching, information, and entertainment--is presented. The numbers of films in each category, especially the last, which includes the animated, unnarrated, iconographic, underground, and avant-garde, has grown substantially. Libraries have quickly accepted all except the revolutionary philosophies…

  12. Selective inorganic thin films

    SciTech Connect

    Phillips, M.L.F.; Pohl, P.I.; Brinker, C.J.

    1997-04-01

    Separating light gases using membranes is a technology area for which there exists opportunities for significant energy savings. Examples of industrial needs for gas separation include hydrogen recovery, natural gas purification, and dehydration. A membrane capable of separating H{sub 2} from other gases at high temperatures could recover hydrogen from refinery waste streams, and facilitate catalytic dehydrogenation and the water gas shift (CO + H{sub 2}O {yields} H{sub 2} + CO{sub 2}) reaction. Natural gas purification requires separating CH{sub 4} from mixtures with CO{sub 2}, H{sub 2}S, H{sub 2}O, and higher alkanes. A dehydrating membrane would remove water vapor from gas streams in which water is a byproduct or a contaminant, such as refrigeration systems. Molecular sieve films offer the possibility of performing separations involving hydrogen, natural gas constituents, and water vapor at elevated temperatures with very high separation factors. It is in applications such as these that the authors expect inorganic molecular sieve membranes to compete most effectively with current gas separation technologies. Cryogenic separations are very energy intensive. Polymer membranes do not have the thermal stability appropriate for high temperature hydrogen recovery, and tend to swell in the presence of hydrocarbon natural gas constituents. The authors goal is to develop a family of microporous oxide films that offer permeability and selectivity exceeding those of polymer membranes, allowing gas membranes to compete with cryogenic and adsorption technologies for large-scale gas separation applications.

  13. Soap film gas flowmeter

    SciTech Connect

    Lalin, H.S.; Bermudez, J.E.; Fleming, W.T.

    1987-09-08

    A soap film gas flowmeter is described comprising: a flow tube having a hollow body with opposite open ends through which a soap film is propelled and a first closed chamber housing a soap solution. It also includes means for supporting the flow tube in a substantially vertical position with the open bottom end of the flow tube disposed in the first chamber above the soap solution; a second closed chamber into which the open top end of the flow tube extends and gas inlet means for introducing gas into the first chamber at a flow rate to be measured using the flowmeters. A gas exit means is included for discharging the gas introduced into the first chamber through the second chamber. Plus there are means for generating a single soap bubble from the soap solution substantially at the bottom end of the flow tube and a relatively large opening in the flowtube for providing an open passageway for inlet gas to pass through the flowtube when the bottom open end of the flowtube is covered by the soap solution.

  14. Thermopower of thin iron films

    NASA Astrophysics Data System (ADS)

    Schepis, Randy; Schröder, Klaus

    1992-02-01

    Thin iron films were prepared by evaporation in a high vacuum system (pressure in the 10 -5 MPa range). The thermopower was measured in situ near room temperature as a function of film thickness. Iron films with rather high resistivity values showed a strong thickness effect of the Seeback coefficient, S, with the difference between S (bulk) and S (film) reaching values of up to (19±3) μV/K for a sample 5 nm thick. The difference between S (bulk) and S (film) decreased with increasing d values. However, a sample with a resistance value of 50 μΩ cm at d = 5 n had an S value which differed by less than 3 μV/K from S (bulk).

  15. A new radiochromic dosimeter film

    NASA Astrophysics Data System (ADS)

    Sidney, L. N.; Lynch, D. C.; Willet, P. S.

    By employing acid-sensitive leuco dyes in a chlorine-containing polymer matrix, a new radiochromic dosimeter film has been developed for gamma, electron beam, and ultraviolet radiation. These dosimeter films undergo a color change from colorless to royal blue, red fuchsia, or black, depending on dye selection, and have been characterized using a visible spectrophotometer over an absorbed dose range of 1 to 100 kGy. The primary features of the film are improved color stability before and after irradiation, whether stored in the dark or under artificial lights, and improved moisture resistance. The effects of absorbed dose, dose rate, and storage conditions on dosimeter performance are discussed. The dosimeter material may be produced as a free film or coated onto a transparent substrate and optionally backed with adhesive. Potential applications for these materials include gamma sterilization indicator films for food and medical products, electron beam dosimeters, and in-line radiation monitors for electron beam and ultraviolet processing.

  16. Anode film formation and control

    DOEpatents

    Koski, O.; Marschman, S.C.

    1990-05-01

    A protective film is created about the anode within a cryolite-based electrolyte during electrolytic production of aluminum from alumina. The film functions to minimize corrosion of the anode by the cryolitic electrolyte and thereby extend the life of the anode. Various operating parameters of the electrolytic process are controlled to maintain the protective film about the anode in a protective state throughout the electrolytic reduction of alumina. Such parameters include electrolyte temperature, electrolyte ratio, current density, and Al[sub 2]O[sub 3] concentration. An apparatus is also disclosed to enable identification of the onset of anode corrosion due to disruption of the film to provide real time information regarding the state of the film. 3 figs.

  17. Anode film formation and control

    DOEpatents

    Koski, Oscar; Marschman, Steven C.

    1990-01-01

    A protective film is created about the anode within a cryolite-based electrolyte during electrolytic production of aluminum from alumina. The film function to minimize corrosion of the anode by the cryolitic electrolyte and thereby extend the life of the anode. Various operating parameters of the electrolytic process are controlled to maintain the protective film about the anode in a protective state throughout the electrolytic reduction of alumina. Such parameters include electrolyte temperature, electrolyte ratio, current density, and Al.sub.2 O.sub.3 concentration. An apparatus is also disclosed to enable identification of the onset of anode corrosion due to disruption of the film to provide real time information regarding the state of the film.

  18. Film Fabrication Technologies at NREL

    NASA Technical Reports Server (NTRS)

    Mcconnell, Robert D.

    1993-01-01

    The National Renewable Energy Laboratory (NREL) has extensive capabilities for fabricating a variety of high-technology films. Much of the in-house work in NREL's large photovoltaics (PV) program involves the fabrication of multiple thin-film semiconducting layers constituting a thin-film PV device. NREL's smaller program in superconductivity focuses on the fabrication of superconducting films on long, flexible tape substrates. This paper focuses on four of NREL's in-house research groups and their film fabrication techniques, developed for a variety of elements, alloys, and compounds to be deposited on a variety of substrates. As is the case for many national laboratories, NREL's technology transfer efforts are focusing on Cooperative Research and Development Agreements (CRADA's) between NREL researchers and private industry researchers.

  19. Contributions of Film Introductions and Film Summaries to Learning from Instructional Films.

    ERIC Educational Resources Information Center

    Lathrop, C. W., Jr.; Norford, C. A.

    An exploratory study of the contribution to learning of typical introductory and summarizing sequences in instructional films underlined the need for further experimental work to determine what kinds of introductory and concluding sequences are most useful in promoting learning from films. The first part of the study was concerned with film…

  20. Film thickness for different regimes of fluid-film lubrication

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.

    1980-01-01

    Film thickness equations are provided for four fluid-film lubrication regimes found in elliptical contacts. These regimes are isoviscous-rigid; viscous-rigid; elastohydrodynamic lubrication of low-elastic-modulus materials (soft EHL), or isoviscous-elastic; and elastohydrodynamic lubrication of high-elastic-modulus materials (hard EHL), or viscous-elastic. The influence or lack of influence of elastic and viscous effects is the factor that distinguishes these regimes. The results are presented as a map of the lubrication regimes, with film thickness contours on a log-log grid of the viscosity and elasticity for three values of the ellipticity parameter.

  1. Effects on film structure on mechanical and adhesion properties of latex films

    SciTech Connect

    Charmeau, J.Y.; Holl, Y.; Kientz, E.

    1995-12-31

    In order to investigate the effect of the particular structure of latex films on mechanical (stress-strain behavior) and adhesion (measured by peeling) properties, this work compares these characteristics for latex films and corresponding {open_quotes}solution films{close_quotes}. Solution films were obtained by dissolving the latex film in an appropriate solvent and forming a new film by evaporating the solvent. Four different systems were studied. It was shown that latex films have Young`s moduli systematically much higher than the corresponding solution films. This is due to the fact that the hydrophilic shells of the latex particles form a continuous phase in the latex film which increases the modulus thanks to polar interactions. However, adhesion energy for latex films is always smaller than for solution films. This is interpreted in terms of structure of the film-support interface and dissipative processes within the bulk of the films.

  2. Ferromagnetic thin films

    DOEpatents

    Krishnan, K.M.

    1994-12-20

    A ferromagnetic [delta]-Mn[sub 1[minus]x]Ga[sub x] thin film having perpendicular anisotropy is described which comprises: (a) a GaAs substrate, (b) a layer of undoped GaAs overlying said substrate and bonded thereto having a thickness ranging from about 50 to about 100 nanometers, (c) a layer of [delta]-Mn[sub 1[minus]x]Ga[sub x] overlying said layer of undoped GaAs and bonded thereto having a thickness ranging from about 20 to about 30 nanometers, and (d) a layer of GaAs overlying said layer of [delta]-Mn[sub 1[minus]x]Ga[sub x] and bonded thereto having a thickness ranging from about 2 to about 5 nanometers, wherein x is 0.4[+-]0.05. 7 figures.

  3. Thin film hydrogen sensor

    DOEpatents

    Lauf, R.J.; Hoffheins, B.S.; Fleming, P.H.

    1994-11-22

    A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed. 6 figs.

  4. Ferromagnetic thin films

    DOEpatents

    Krishnan, Kannan M.

    1994-01-01

    A ferromagnetic .delta.-Mn.sub.1-x Ga.sub.x thin film having perpendicular anisotropy is described which comprises: (a) a GaAs substrate, (b) a layer of undoped GaAs overlying said substrate and bonded thereto having a thickness ranging from about 50 to about 100 nanometers, (c) a layer of .delta.-Mn.sub.1-x Ga.sub.x overlying said layer of undoped GaAs and bonded thereto having a thickness ranging from about 20 to about 30 nanometers, and (d) a layer of GaAs overlying said layer of .delta.-Mn.sub.1-x Ga.sub.x and bonded thereto having a thickness ranging from about 2 to about 5 nanometers, wherein x is 0.4 .+-.0.05.

  5. Polyimide Aerogel Thin Films

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann; Guo, Haiquan

    2012-01-01

    Polyimide aerogels have been crosslinked through multifunctional amines. This invention builds on "Polyimide Aerogels With Three-Dimensional Cross-Linked Structure," and may be considered as a continuation of that invention, which results in a polyimide aerogel with a flexible, formable form. Gels formed from polyamic acid solutions, end-capped with anhydrides, and cross-linked with the multifunctional amines, are chemically imidized and dried using supercritical CO2 extraction to give aerogels having density around 0.1 to 0.3 g/cubic cm. The aerogels are 80 to 95% porous, and have high surface areas (200 to 600 sq m/g) and low thermal conductivity (as low as 14 mW/m-K at room temperature). Notably, the cross-linked polyimide aerogels have higher modulus than polymer-reinforced silica aerogels of similar density, and can be fabricated as both monoliths and thin films.

  6. Antimicrobial edible films and coatings.

    PubMed

    Cagri, Arzu; Ustunol, Zeynep; Ryser, Elliot T

    2004-04-01

    Increasing consumer demand for microbiologically safer foods, greater convenience, smaller packages, and longer product shelf life is forcing the industry to develop new food-processing, cooking, handling, and packaging strategies. Nonfluid ready-to-eat foods are frequently exposed to postprocess surface contamination, leading to a reduction in shelf life. The food industry has at its disposal a wide range of nonedible polypropylene- and polyethylene-based packaging materials and various biodegradable protein- and polysaccharide-based edible films that can potentially serve as packaging materials. Research on the use of edible films as packaging materials continues because of the potential for these films to enhance food quality, food safety, and product shelf life. Besides acting as a barrier against mass diffusion (moisture, gases, and volatiles), edible films can serve as carriers for a wide range of food additives, including flavoring agents, antioxidants, vitamins, and colorants. When antimicrobial agents such as benzoic acid, sorbic acid, propionic acid, lactic acid, nisin, and lysozyme have been incorporated into edible films, such films retarded surface growth of bacteria, yeasts, and molds on a wide range of products, including meats and cheeses. Various antimicrobial edible films have been developed to minimize growth of spoilage and pathogenic microorganisms, including Listeria monocytogenes, which may contaminate the surface of cooked ready-to-eat foods after processing. Here, we review the various types of protein-based (wheat gluten, collagen, corn zein, soy, casein, and whey protein), polysaccharide-based (cellulose, chitosan, alginate, starch, pectin, and dextrin), and lipid-based (waxes, acylglycerols, and fatty acids) edible films and a wide range of antimicrobial agents that have been or could potentially be incorporated into such films during manufacture to enhance the safety and shelf life of ready-to-eat foods.

  7. Language, Culture, and the Feature Film.

    ERIC Educational Resources Information Center

    Straub, Hans

    2002-01-01

    Suggests that one way to provide cultural contexts for language learning is by using feature films for instructional purposes. Highlights the benefits of feature films, discusses the selection of films, and describes a process for using feature films in the language classroom. (Author/VWL)

  8. FILM WORKSHOP SUCCESSFUL WITH TSU STUDENTS.

    ERIC Educational Resources Information Center

    BAHRENBERG, JIM

    AN UPWARD BOUND FILM WORKSHOP AT TEXAS SOUTHERN UNIVERSITY EXPOSED STUDENTS TO FILMS AS A CREATIVE ART FORM, A MEANS OF COMMUNICATION, AND A BASIS FOR DISCUSSING VALUES. IN ADDITION TO VIEWING SEVERAL SHORT, PROFESSIONALLY-DEVELOPED FILMS, STUDENTS WROTE AND PRODUCED TWO OF THEIR OWN. ONE STUDENT-PRODUCED FILM--A LIGHT SHOW--ILLUMINATED THE UNITY…

  9. EFFECT OF REPETITIVE FILM SHOWINGS ON LEARNING.

    ERIC Educational Resources Information Center

    MCTAVISH, C.L.; AND OTHERS

    A DETERMINATION OF THE INCREMENT IN LEARNING ATTRIBUTABLE SOLELY TO ONE, TWO, AND THREE REPETITIONS OF A FILM OVER AND ABOVE A SINGLE SHOWING WAS INVESTIGATED. THE SUBJECTS WERE 319 COLLEGE FRESHMEN WHO WERE DIVIDED INTO FOUR GROUPS AND WHO WERE SHOWN FOUR GENERAL SCIENCE FILMS. EACH GROUP SAW ONE OF THE FILMS ONCE, A SECOND FILM TWICE, A THIRD…

  10. Geoflicks Reviewed--Films about Hawaiian Volcanoes.

    ERIC Educational Resources Information Center

    Bykerk-Kauffman, Ann

    1994-01-01

    Reviews 11 films on volcanic eruptions in the United States. Films are given a one- to five-star rating and the film's year, length, source and price are listed. Top films include "Inside Hawaiian Volcanoes" and "Kilauea: Close up of an Active Volcano." (AIM)

  11. Historical Films in the Latin Classroom.

    ERIC Educational Resources Information Center

    Buller, Jeffrey L.

    Guidelines and lesson plans are presented for teachers of Latin using historical films as instructional and support materials. A discussion of the use of historical films addresses these issues in classroom practice: the legality of using films in the classroom (copyrights); techniques for using historical films as sources of cultural information;…

  12. "Space slitter" for film or tape

    NASA Technical Reports Server (NTRS)

    Johnson, W. H.

    1978-01-01

    Device cuts film or tape into strips by guiding film in channel under cutting blades. Device is operated by lifting pressure bar to insert blades into film. Film is then pulled through blades. Cutter has potential uses in advertising, commercial art, and publishing fields.

  13. 19 CFR 12.41 - Prohibited films.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Prohibited films. 12.41 Section 12.41 Customs... SPECIAL CLASSES OF MERCHANDISE Immoral Articles § 12.41 Prohibited films. (a) Importers of films, shall certify on Customs Form 3291 that the imported films contain no obscene or immoral matter, nor any...

  14. 19 CFR 12.41 - Prohibited films.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Prohibited films. 12.41 Section 12.41 Customs... SPECIAL CLASSES OF MERCHANDISE Immoral Articles § 12.41 Prohibited films. (a) Importers of films, shall certify on Customs Form 3291 that the imported films contain no obscene or immoral matter, nor any...

  15. 19 CFR 12.41 - Prohibited films.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Prohibited films. 12.41 Section 12.41 Customs... SPECIAL CLASSES OF MERCHANDISE Immoral Articles § 12.41 Prohibited films. (a) Importers of films, shall certify on Customs Form 3291 that the imported films contain no obscene or immoral matter, nor any...

  16. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  17. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  18. 19 CFR 12.41 - Prohibited films.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Prohibited films. 12.41 Section 12.41 Customs... SPECIAL CLASSES OF MERCHANDISE Immoral Articles § 12.41 Prohibited films. (a) Importers of films, shall certify on Customs Form 3291 that the imported films contain no obscene or immoral matter, nor any...

  19. 19 CFR 12.41 - Prohibited films.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Prohibited films. 12.41 Section 12.41 Customs... SPECIAL CLASSES OF MERCHANDISE Immoral Articles § 12.41 Prohibited films. (a) Importers of films, shall certify on Customs Form 3291 that the imported films contain no obscene or immoral matter, nor any...

  20. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  1. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  2. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  3. Using Popular Children's Films in Science

    ERIC Educational Resources Information Center

    Wadsworth, Elle; Croker, Stev; Harrison, Tim

    2012-01-01

    Watching films is a common activity for children outside of school, and incorporating popular films that contain scientific references has the potential to spark interest in the classroom. Clips rather than entire films can be used, as the children will maintain focus on the lesson objectives while being excited by the appeal of the film. The use…

  4. Subjective Sexual Arousal to Films of Masturbation

    ERIC Educational Resources Information Center

    Mosher, Donald L.; Abramson, Paul R.

    1977-01-01

    A film of a male or female masturbating was viewed by 96 males and 102 females. Males reported the highest level of sexual arousal to the female film and the lowest level of arousal to the male film. Females were sexually aroused by both films. (Author)

  5. A 3M high temperature dielectric film

    NASA Technical Reports Server (NTRS)

    Hampl, Edward, Jr.

    1994-01-01

    The performance characteristics of a dielectric film are summarized. Additionally, the film's environmental and chemical properties are listed: low shrinkage to 300 C; moisture insensitive; low outgassing under vacuum; excellent surface qualities--easy metallization of film; flame retardant; and low smoke generation. A series of graphs that display the performance characteristics of the film are also presented.

  6. Focus on Young Film Makers: Student Film Making--Types and Techniques.

    ERIC Educational Resources Information Center

    Putsch, Henry E.

    1968-01-01

    Brief descriptions of 10 styles of student film making include references to specific films employing the techniques. The styles of film making listed are animation, pixillation animation, collage, draw-on, documentary, bio-documentary, story line, impressionistic, commercials, and the school film. Directions for submitting films to the Young Film…

  7. American Film Genres: Approaches to a Critical Theory of Popular Film.

    ERIC Educational Resources Information Center

    Kaminsky, Stuart M.

    This book is divided into twelve sections and contains photographs from many of the films discussed. The introduction defines film genre and describes the general theories behind this book; "The Individual Film" analyzes the film "Little Caesar" as it relates to the genre of gangster films; "Comparative Forms"…

  8. Surface wrinkling on polydopamine film

    NASA Astrophysics Data System (ADS)

    Meng, Jieyun; Xie, Jixun; Han, Xue; Lu, Conghua

    2016-05-01

    In this paper, we report a non-lithographic strategy to realize surface patterns on polydopamine films. It is based on surface wrinkling, which is induced on polydopamine (PDA) films that are grown on uniaxially pre-strained polydimethylsiloxane (PDMS) substrates through self-polymerization of dopamine, followed by the pre-strain release. We investigate the influences of the experimental conditions including polymerization time, prestrain and the dopamine solution concentration on the wrinkling patterns. Furthermore, we take advantage of the reducibility of PDA to fabricate silver nanoparticle-deposited PDA films with surface-wrinkled patterns, which may have potential applications in the related fields.

  9. Ultrathin Polymer Films for Microlithography

    DTIC Science & Technology

    1988-07-13

    exposure the PINAA was developed in a solution made of 3:7 cellosolve : methanol for 13 seconds. Cellosolve was chosen because it is strong enough to...can achieve on thicker resist (> 100 nm) for the same exposure conditions. Recently, we have exposed 14.3 nrm L-B PMMA films on a high resolution...Polymer Films LB PMMA Spin-Cast PNMA Spin-Cast Novolac (10 wafers) (5 wafers) (5 wafers) Film Thickness 14.3 nrm 14 nrm 22 nm Pinhole Density < 10/cm 2

  10. Surface nanostructures in manganite films.

    PubMed

    Gambardella, A; Graziosi, P; Bergenti, I; Prezioso, M; Pullini, D; Milita, S; Biscarini, F; Dediu, V A

    2014-06-19

    Ultrathin manganite films are widely used as active electrodes in organic spintronic devices. In this study, a scanning tunnelling microscopy (STM) investigation with atomic resolution revealed previously unknown surface features consisting of small non-stoichiometric islands. Based upon this evidence, a new mechanism for the growth of these complex materials is proposed. It is suggested that the non-stoichiometric islands result from nucleation centres that are below the critical threshold size required for stoichiometric crystalline growth. These islands represent a kinetic intermediate of single-layer growth regardless of the film thickness, and should be considered and possibly controlled in manganite thin-film applications.

  11. Film boiling of mercury droplets

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.; Schoessow, G. J.; Chmielewski, C. E.

    1975-01-01

    Vaporization times of mercury droplets in Leidenfrost film boiling on a flat horizontal plate are measured in an air atmosphere. Extreme care was used to prevent large amplitude droplet vibrations and surface wetting; therefore, these data can be compared to film boiling theory. Diffusion from the upper surface of the drop appears as a dominant mode of mass transfer from the drop. A closed-form analytical film boiling theory is developed to account for the diffusive evaporation. Reasonable agreement between data and theory is seen.

  12. Tailoring nanocrystalline diamond film properties

    DOEpatents

    Gruen, Dieter M.; McCauley, Thomas G.; Zhou, Dan; Krauss, Alan R.

    2003-07-15

    A method for controlling the crystallite size and growth rate of plasma-deposited diamond films. A plasma is established at a pressure in excess of about 55 Torr with controlled concentrations of hydrogen up to about 98% by volume, of unsubstituted hydrocarbons up to about 3% by volume and an inert gas of one or more of the noble gases and nitrogen up to about 98% by volume. The volume ratio of inert gas to hydrogen is preferably maintained at greater than about 4, to deposit a diamond film on a suitable substrate. The diamond film is deposited with a predetermined crystallite size and at a predetermined growth rate.

  13. Photovoltaic properties of polymer films

    NASA Astrophysics Data System (ADS)

    Reucroft, P. J.; Ullal, H.

    1980-03-01

    The effect of metal electrode and film thickness on the photovoltaic energy conversion efficiency in (1:1) mole ratio films of poly (N-vinylcarbazole) (PVK) and 2,4,7-trinitrofluorenone (TNF) has been investigated. Low work function metals increase the Schottky barrier height which leads to increases in the photovoltaic energy conversion efficiency. A ten-fold decrease in film thickness produces a thousand-fold increase in photovoltaic energy conversion efficiency. A theoretical model which assumes that the photovoltaic current is limited by Child's law predicts photovoltaic efficiencies which are in good agreement with the measured efficiencies.

  14. Surface Nanostructures in Manganite Films

    PubMed Central

    Gambardella, A.; Graziosi, P.; Bergenti, I.; Prezioso, M.; Pullini, D.; Milita, S.; Biscarini, F.; Dediu, V. A.

    2014-01-01

    Ultrathin manganite films are widely used as active electrodes in organic spintronic devices. In this study, a scanning tunnelling microscopy (STM) investigation with atomic resolution revealed previously unknown surface features consisting of small non-stoichiometric islands. Based upon this evidence, a new mechanism for the growth of these complex materials is proposed. It is suggested that the non-stoichiometric islands result from nucleation centres that are below the critical threshold size required for stoichiometric crystalline growth. These islands represent a kinetic intermediate of single-layer growth regardless of the film thickness, and should be considered and possibly controlled in manganite thin-film applications. PMID:24941969

  15. Liquid-film electron stripper

    DOEpatents

    Leemann, B.T.; Yourd, R.B.

    1982-03-09

    A thin freestanding oil film is produced in vacuum by directing an oil stream radially inward to the hollow-ground sharp outer edge of a rotating disc. The sides of the edge are roughened somewhat to aid in dispersing oil from the disc. Oil is removed from the surface of disc to prevent formation of oil droplets which might spin off the disc and disrupt the oil film. An ion beam is directed through the thin oil film so that electrons are stripped from the ions to increase their charge.

  16. Liquid-film electron stripper

    DOEpatents

    Leemann, Beat T.; Yourd, Roland B.

    1984-01-01

    A thin freestanding oil film is produced in vacuum by directing an oil stream radially inward to the hollow-ground sharp outer edge of a rotating disc. The sides of the edge are roughened somewhat to aid in dispersing oil from the disc. Oil is removed from the surface of disc to prevent formation of oil droplets which might spin off the disc and disrupt the oil film. An ion beam is directed through the thin oil film so that electrons are stripped from the ions to increase their charge.

  17. Film boiling of mercury droplets

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.; Schoessow, G. J.; Chmielewski, C. E.

    1975-01-01

    Vaporization times of mercury droplets in Leidenfrost film boiling on a flat horizontal plate are measured in an air atmosphere. Extreme care was used to prevent large amplitude droplet vibrations and surface wetting; therefore, these data can be compared to film boiling theory. For these data, diffusion from the upper surface of the drop is a dominant mode of mass transfer from the drop. A closed-form analytical film boiling theory is developed to account for the diffusive evaporation. Reasonable agreement between data and theory is seen.

  18. Vapor deposition of thin films

    DOEpatents

    Smith, David C.; Pattillo, Stevan G.; Laia, Jr., Joseph R.; Sattelberger, Alfred P.

    1992-01-01

    A highly pure thin metal film having a nanocrystalline structure and a process of preparing such highly pure thin metal films of, e.g., rhodium, iridium, molybdenum, tungsten, rhenium, platinum, or palladium by plasma assisted chemical vapor deposition of, e.g., rhodium(allyl).sub.3, iridium(allyl).sub.3, molybdenum(allyl).sub.4, tungsten(allyl).sub.4, rhenium(allyl).sub.4, platinum(allyl).sub.2, or palladium(allyl).sub.2 are disclosed. Additionally, a general process of reducing the carbon content of a metallic film prepared from one or more organometallic precursor compounds by plasma assisted chemical vapor deposition is disclosed.

  19. Importance of combining convection with film cooling

    NASA Technical Reports Server (NTRS)

    Colladay, R. S.

    1971-01-01

    The interaction of film and convection cooling and its effect on wall cooling efficiency is investigated analytically for two cooling schemes for advanced gas turbine applications. The two schemes are full coverage- and counterflow-film cooling. In full coverage film cooling, the cooling air issues from a large number of small discrete holes in the surface. Counterflow film cooling is a film-convection scheme with film injection from a slot geometry. The results indicate that it is beneficial to utilize as much of the cooling air heat sink as possible for convection cooling prior to ejecting it as a film.

  20. Importance of combining convection with film cooling.

    NASA Technical Reports Server (NTRS)

    Colladay, R. S.

    1972-01-01

    The interaction of film and convection cooling and its effect on wall cooling efficiency is investigated analytically for two cooling schemes for advanced gas turbine applications. The two schemes are full coverage- and counterflow-film cooling. In full coverage film cooling, the cooling air issues from a large number of small discrete holes in the surface. Counterflow film cooling is a film-convection scheme with film injection from a slot geometry. The results indicate that it is beneficial to utilize as much of the cooling air heat sink as possible for convection cooling prior to ejecting it as a film.