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Sample records for three-layer antireflection coating

  1. Sol-gel antireflective coating on plastics

    Science.gov (United States)

    Ashley, Carol S.; Reed, Scott T.

    1990-01-01

    An antireflection film made from a reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

  2. Investigation of sol-gel antireflective coatings

    International Nuclear Information System (INIS)

    Schmid, A.; Guardalben, M.; Chipp, T.

    1984-03-01

    Very high power laser systems present material design challenges which often approach the inherent optical survival strength of components. Optical coatings in the UV region suffer from anomalously high absorption and scattering in the deposited layers. The losses caused by these effects are often unacceptable or, in the case of absorption, usually fatal to the absorbing coatings. Unfortunately, no metals exist that have high enough reflectivities in the UV to serve as uncoated mirrors as they normally do in the CO 2 region of the infrared. Adequate multilayer dielectric coatings are therefore critically important for the development and utilization of UV lasers. The same could be said for relfection suppressing antireflective coatings in that wavelength range. Antireflective properties of gradientindex designs have been rediscovered and their potential for resolving UV laser design difficulties has been vigorously tested. These antireflective properties have been attained on glass or fused silica surfaces by chemical surface treatments

  3. ANTIREFLECTION MULTILAYER COATINGS WITH THIN METAL LAYERS

    Directory of Open Access Journals (Sweden)

    L. A. Gubanova

    2016-03-01

    Full Text Available The design of anti-reflective coatings for metal surfaces of Al, Ti, N,i Cr is proposed. The coatings have the form of alternating layers of dielectric/metal/dielectric with the number of cells up to15. The method of calculation of such coatings is proposed. We have calculated the coatings of the type [HfO2/Cr/HfO2]15, [ZrO2/Ti/Al2O3]15, [ZrO2/Cr/ZrO2]15. It is shown that the proposed interference coatings provide reduction of the residual reflectance of the metal several times (from 3.5 to 6.0 in a wide spectral range (300-1000 nm. The proposed coatings can be recommended as anti-reflective coatings for energy saving solar systems and batteries, and photovoltaic cells.

  4. Antireflection coatings on plastics deposited by plasma ...

    Indian Academy of Sciences (India)

    Wintec

    Antireflection coatings (ARCs) are deposited on the surfaces of optical elements like spectacle lenses to increase light transmission and improve their performance. In the ophthalmic .... silica layer (Zajickova et al 1998, 2001; Benitez et al. 2000; Kuhr et al 2003 .... by the contact angle of a water drop on the surface. Due to its ...

  5. Subwavelength single layer absorption resonance antireflection coatings

    NARCIS (Netherlands)

    Huber, S. P.; van de Kruijs, R. W. E.; Yakshin, A. E.; Zoethout, E.; Boller, K.-J.; F. Bijkerk,

    2014-01-01

    We present theoretically derived design rules for an absorbing resonance antireflection coating for the spectral range of 100 &\\#x02013; 400 nm, applied here on top of a molybdenum-silicon multilayer mirror (Mo/Si MLM) as commonly used in extreme ultraviolet lithography. The design rules for

  6. Subwavelength single layer absorption resonance antireflection coatings

    NARCIS (Netherlands)

    Huber, Sebastiaan; van de Kruijs, Robbert Wilhelmus Elisabeth; Yakshin, Andrey; Zoethout, E.; Boller, Klaus J.; Bijkerk, Frederik

    2014-01-01

    We present theoretically derived design rules for an absorbing resonance antireflection coating for the spectral range of 100−400 nm, applied here on top of a molybdenum-silicon multilayer mirror (Mo/Si MLM) as commonly used in extreme ultraviolet lithography. The design rules for optimal

  7. Plasmonic and silicon spherical nanoparticle antireflective coatings

    Science.gov (United States)

    Baryshnikova, K. V.; Petrov, M. I.; Babicheva, V. E.; Belov, P. A.

    2016-03-01

    Over the last decade, plasmonic antireflecting nanostructures have been extensively studied to be utilized in various optical and optoelectronic systems such as lenses, solar cells, photodetectors, and others. The growing interest to all-dielectric photonics as an alternative optical technology along with plasmonics motivates us to compare antireflective properties of plasmonic and all-dielectric nanoparticle coatings based on silver and crystalline silicon respectively. Our simulation results for spherical nanoparticles array on top of amorphous silicon show that both silicon and silver coatings demonstrate strong antireflective properties in the visible spectral range. For the first time, we show that zero reflectance from the structure with silicon coatings originates from the destructive interference of electric- and magnetic-dipole responses of nanoparticle array with the wave reflected from the substrate, and we refer to this reflection suppression as substrate-mediated Kerker effect. We theoretically compare the silicon and silver coating effectiveness for the thin-film photovoltaic applications. Silver nanoparticles can be more efficient, enabling up to 30% increase of the overall absorbance in semiconductor layer. Nevertheless, silicon coatings allow up to 64% absorbance increase in the narrow band spectral range because of the substrate-mediated Kerker effect, and band position can be effectively tuned by varying the nanoparticles sizes.

  8. AntiReflection Coating D

    International Nuclear Information System (INIS)

    AIKEN, DANIEL J.

    1999-01-01

    Analytical expressions used to optimize AR coatings for single junction solar cells are extended for use in monolithic, series interconnected multi-junction solar cell AR coating design. The result is an analytical expression which relates the solar cell performance (through J(sub sc)) directly to the AR coating design through the device reflectance. It is also illustrated how AR coating design be used to provide an additional degree of freedom for current matching multi-junction devices

  9. High gain durable anti-reflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Brophy, Brenor L.; Colson, Thomas E.; Gonsalves, Peter R.; Abrams, Ze' ev R.

    2017-06-27

    Disclosed herein are polysilsesquioxane-based anti-reflective coating (ARC) compositions, methods of preparation, and methods of deposition on a substrate. In one embodiment, the polysilsesquioxane of this disclosure is prepared in a two-step process of acid catalyzed hydrolysis of organoalkoxysilane followed by addition of tetralkoxysilane that generates silicone polymers with >40 mol % silanol based on Si-NMR. These high silanol siloxane polymers are stable and have a long shelf-life in polar organic solvents at room temperature. Also disclosed are low refractive index ARC made from these compositions with and without additives such as porogens, templates, thermal radical initiator, photo radical initiators, crosslinkers, Si--OH condensation catalyst and nano-fillers. Also disclosed are methods and apparatus for applying coatings to flat substrates including substrate pre-treatment processes, coating processes and coating curing processes including skin-curing using hot-air knives. Also disclosed are coating compositions and formulations for highly tunable, durable, highly abrasion-resistant functionalized anti-reflective coatings.

  10. Witness sample preparation for measuring antireflection coatings.

    Science.gov (United States)

    Willey, Ronald R

    2014-02-01

    Measurement of antireflection coating of witness samples from across the worldwide industry has been shown to have excess variability from a sampling taken for the OSA Topical Meeting on Optical Interference Coatings: Measurement Problem. Various sample preparation techniques have been discussed with their limitations, and a preferred technique is recommended with its justification, calibration procedures, and limitations. The common practice of grinding the second side to reduce its reflection is less than satisfactory. One recommended practice is to paint the polished second side, which reduces its reflection to almost zero. A method to evaluate the suitability of given paints is also described.

  11. Comparative Study of Antireflection Coating Materials for Solar ...

    African Journals Online (AJOL)

    yaog

    2017-01-17

    Jan 17, 2017 ... Locally available absorber and antireflection coating materials for ... However, a black painted steel sheet metal costs less and is readily available in local ..... Testing of a new solar coating for solar water heating applications.

  12. Self-Cleaning Antireflective Optical Coatings

    KAUST Repository

    Guldin, Stefan

    2013-11-13

    Low-cost antireflection coatings (ARCs) on large optical surfaces are an ingredient-technology for high-performance solar cells. While nanoporous thin films that meet the zero-reflectance conditions on transparent substrates can be cheaply manufactured, their suitability for outdoor applications is limited by the lack of robustness and cleanability. Here, we present a simple method for the manufacture of robust self-cleaning ARCs. Our strategy relies on the self-assembly of a block-copolymer in combination with silica-based sol-gel chemistry and preformed TiO2 nanocrystals. The spontaneous dense packing of copolymer micelles followed by a condensation reaction results in an inverse opal-type silica morphology that is loaded with TiO2 photocatalytic hot-spots. The very low volume fraction of the inorganic network allows the optimization of the antireflecting properties of the porous ARC despite the high refractive index of the embedded photocatalytic TiO2 nanocrystals. The resulting ARCs combine high optical and self-cleaning performance and can be deposited onto flexible plastic substrates. © 2013 American Chemical Society.

  13. Organic antireflective coatings for 193-nm lithography

    Science.gov (United States)

    Trefonas, Peter, III; Blacksmith, Robert F.; Szmanda, Charles R.; Kavanagh, Robert J.; Adams, Timothy G.; Taylor, Gary N.; Coley, Suzanne; Pohlers, Gerd

    1999-06-01

    Organic anti-reflective coatings (ARCs) continue to play an important role in semiconductor manufacturing. These materials provide a convenient means of greatly reducing the resist photospeed swing and reflective notching. In this paper, we describe a novel class of ARC materials optimized for lithographic applications using 193 nm exposure tools. These ARCs are based upon polymers containing hydroxyl-alkyl methacrylate monomers for crosslinkable sites, styrene for a chromophore at 193 nm, and additional alkyl-methacrylate monomers as property modifiers. A glycouril crosslinker and a thermally-activated acidic catalyst provide a route to forming an impervious crosslinked film activate data high bake temperatures. ARC compositions can be adjusted to optimize the film's real and imaginary refractive indices. Selection of optimal target indices for 193 nm lithographic processing through simulations is described. Potential chromophores for 193 nm were explored using ZNDO modeling. We show how these theoretical studies were combined with material selection criteria to yield a versatile organic anti-reflectant film, Shipley 193 G0 ARC. Lithographic process data indicates the materials is capable of supporting high resolution patterning, with the line features displaying a sharp resist/ARC interface with low line edge roughness. The resist Eo swing is successfully reduced from 43 percent to 6 percent.

  14. Epoxy-based broadband antireflection coating for millimeter-wave optics.

    Science.gov (United States)

    Rosen, Darin; Suzuki, Aritoki; Keating, Brian; Krantz, William; Lee, Adrian T; Quealy, Erin; Richards, Paul L; Siritanasak, Praween; Walker, William

    2013-11-20

    We have developed epoxy-based, broadband antireflection coatings for millimeter-wave astrophysics experiments with cryogenic optics. By using multiple-layer coatings where each layer steps in dielectric constant, we achieved low reflection over a wide bandwidth. We suppressed the reflection from an alumina disk to 10% over fractional bandwidths of 92% and 104% using two-layer and three-layer coatings, respectively. The dielectric constants of epoxies were tuned between 2.06 and 7.44 by mixing three types of epoxy and doping with strontium titanate powder required for the high dielectric mixtures. At 140 K, the band-integrated absorption loss in the coatings was suppressed to less than 1% for the two-layer coating, and below 10% for the three-layer coating.

  15. Epoxy-based broadband anti-reflection coating for millimeter-wave optics

    OpenAIRE

    Rosen, Darin; Suzuki, Aritoki; Keating, Brian; Krantz, William; Lee, Adrian T.; Quealy, Erin; Richards, Paul L.; Siritanasak, Praween; Walker, William

    2013-01-01

    We have developed epoxy-based, broadband anti-reflection coatings for millimeter-wave astrophysics experiments with cryogenic optics. By using multiple-layer coatings where each layer steps in dielectric constant, we achieved low reflection over a wide bandwidth. We suppressed the reflection from an alumina disk to 10% over fractional bandwidths of 92% and 104% using two-layer and three-layer coatings, respectively. The dielectric constants of epoxies were tuned between 2.06 and 7.44 by mixin...

  16. Advanced Antireflection Coatings for High-Performance Solar Energy Applications

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Phase II objectives: Develop and refine antireflection coatings incorporating lanthanum titanate as an intermediate refractive index material; Investigate wet/dry thermal oxidation of aluminum containing semiconductor compounds as a means of forming a more transparent window layer with equal or better optical properties than its unoxidized form; Develop a fabrication process that allows integration of the oxidized window layer and maintains the necessary electrical properties for contacting the solar cell; Conduct an experimental demonstration of the best candidates for improved antireflection coatings.

  17. Standing Wave Field Distribution in Graded-Index Antireflection Coatings

    Directory of Open Access Journals (Sweden)

    Hongxiang Deng

    2018-01-01

    Full Text Available Standing wave field distributions in three classic types of graded-index antireflection coatings are studied. These graded-index antireflection coatings are designed at wavelengths from 200 nm to 1200 nm, which is the working wavelength range of high energy laser system for inertial-fusion research. The standing wave field distributions in these coatings are obtained by the numerical calculation of electromagnetic wave equation. We find that standing wave field distributions in these three graded-index anti-reflection coatings are quite different. For the coating with linear index distribution, intensity of standing wave field decreases periodically from surface to substrate with narrow oscillation range and the period is proportional to the incident wavelength. For the coating with exponential index distribution, intensity of standing wave field decreases periodically from surface to substrate with large oscillation range and the period is also proportional to the incident wavelength. Finally, for the coating with polynomial index, intensity of standing wave field is quickly falling down from surface to substrate without an obvious oscillation. We find that the intensity of standing wave field in the interface between coating and substrate for linear index, exponential index and polynomial index are about 0.7, 0.9 and 0.7, respectively. Our results indicate that the distributions of standing wave field in linear index coating and polynomial index coating are better than that in exponential index coating for the application in high energy laser system. Moreover, we find that the transmittance of linear index coating and polynomial index coating are also better than exponential index coating at the designed wavelength range. Present simulation results are useful for the design and application of graded-index antireflection coating in high energy laser system.

  18. Antireflection coatings for intraocular lenses of sapphire and fianite

    Energy Technology Data Exchange (ETDEWEB)

    Babin, A.A.; Konoplev, Yu.N.; Mamaev, Yu.A. [Inst. of Applied Physics, Nizhnii Novgorod (Russian Federation)] [and others

    1995-10-01

    Broadband antireflection coatings for intraocular lenses of sapphire and fianite are calculated and implemented practically. Their residual reflectance in the liquid with a refracting index of 1.336 is below 0.2% from each face virtually over the entire visible region. 7 refs., 2 figs., 2 tabs.

  19. Anti-reflection coatings applied by acid leaching process

    Science.gov (United States)

    Pastirik, E.

    1980-01-01

    The Magicote C process developed by S.M. Thompsen was evaluated for use in applying an antireflective coating to the cover plates of solar panels. The process uses a fluosilicic acid solution supersaturated with silica at elevated temperature to selectively attack the surface of soda-lime glass cover plates and alter the physical and chemical composition of a thin layer of glass. The altered glass layer constitutes an antireflective coating. The process produces coatings of excellent optical quality which possess outstanding resistance to soiling and staining. The coatings produced are not resistant to mechanical abrasion and are attacked to some extent by glass cleansers. Control of the filming process was found to be difficult.

  20. Antireflection coating on InP for semiconductor detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hantehzadeh, M.R. [Plasma Physics Research Center, Science and Research Campus of Islamic Azad University, Tehran (Iran, Islamic Republic of)]. E-mail: hanteh@sr.iau.ac.ir; Ghoranneviss, M. [Plasma Physics Research Center, Science and Research Campus of Islamic Azad University, Tehran (Iran, Islamic Republic of); Sari, A.H. [Plasma Physics Research Center, Science and Research Campus of Islamic Azad University, Tehran (Iran, Islamic Republic of); Sahlani, F. [Plasma Physics Research Center, Science and Research Campus of Islamic Azad University, Tehran (Iran, Islamic Republic of); Shokuhi, A. [Plasma Physics Research Center, Science and Research Campus of Islamic Azad University, Tehran (Iran, Islamic Republic of); Shariati, M. [Plasma Physics Research Center, Science and Research Campus of Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2006-10-25

    Aluminum nitride thin film by RF magnetron sputtering is used to produce antireflection coating on InP. The index of refection variation of aluminum nitride for different thickness at different wavelength in the range of 400 to 1500 nm is investigated using reflection spectroscopy. Subsequent Ar+ ion implantation at 30 keV with different doses on these coated layers has been performed. The morphology of aluminum nitride after ion implantation is characterized using atomic force microscopy AFM.

  1. Antireflection coating on InP for semiconductor detectors

    International Nuclear Information System (INIS)

    Hantehzadeh, M.R.; Ghoranneviss, M.; Sari, A.H.; Sahlani, F.; Shokuhi, A.; Shariati, M.

    2006-01-01

    Aluminum nitride thin film by RF magnetron sputtering is used to produce antireflection coating on InP. The index of refection variation of aluminum nitride for different thickness at different wavelength in the range of 400 to 1500 nm is investigated using reflection spectroscopy. Subsequent Ar+ ion implantation at 30 keV with different doses on these coated layers has been performed. The morphology of aluminum nitride after ion implantation is characterized using atomic force microscopy AFM

  2. Antireflection coatings with Chebyshev or Butterworth response - Design

    Science.gov (United States)

    Baumeister, Philip

    1986-12-01

    The approximation of Kard (1971) is used to find values for the refractive indices of nonabsorbing layers with equal optical thickness to produce an antireflection (AR) coating for a dielectric substrate that has a Chebyshev spectral response, with application to the design of bandpass filters. The method is numerically demonstrated with the example of four-layer Chebyshev AR coatings with narrow, medium and wide bandwidths, and substrates of indices 2, 5, and 10. Approximate indices are also given for the case when the radiant reflectance/transmittance of the coating vs frequency is maximally flat (Butterworth response).

  3. Wide spectrum antireflective coating for laser fusion systems. Final report

    International Nuclear Information System (INIS)

    Yoldas, B.E; Partlow, D.P.; Smith, H.D.; Mattox, D.M.

    1984-01-01

    A method of depositing a laser damage resistant, wide-spectrum antireflective coating on fused silica has been developed. This work was sponsored under a subcontract with the University of California, with technical direction from the Lawrence Livermore National Laboratory. The coating is applied from a specific silanol polymer solution and converted to a porous SiO 2 film. The pore size of the film is first reduced by a heat treatment to prevent uv scattering. Then gradation of the pore volume is achieved by a mild etching to a sufficient depth to prevent a smoother index transition from air to the substrate glass. The resulting antireflectivity covers the entire transmission range of silica and may be extended to a wavelength as short as 250 nm. Laser damage thresholds as high as 9 j/cm 2 have been demonstrated on processed samples

  4. Gradient SiNO anti-reflective layers in solar selective coatings

    Science.gov (United States)

    Ren, Zhifeng; Cao, Feng; Sun, Tianyi; Chen, Gang

    2017-08-01

    A solar selective coating includes a substrate, a cermet layer having nanoparticles therein deposited on the substrate, and an anti-reflection layer deposited on the cermet layer. The cermet layer and the anti-reflection layer may each be formed of intermediate layers. A method for constructing a solar-selective coating is disclosed and includes preparing a substrate, depositing a cermet layer on the substrate, and depositing an anti-reflection layer on the cermet layer.

  5. Ellipsometry of single-layer antireflection coatings on transparent substrates

    Science.gov (United States)

    Azzam, R. M. A.

    2017-11-01

    The complex reflection coefficients of p- and s-polarized light and ellipsometric parameters of a transparent substrate of refractive index n2, which is coated by a transparent thin film whose refractive index n1 =√{n2 } satisfies the anti-reflection condition at normal incidence, are considered as functions of film thickness d and angle of incidence ϕ. A unique coated surface, with n1 =√{n2 } and film thickness d equal to half of the film-thickness period Dϕ at angle ϕ and wavelength λ, reflects light of the same wavelength without change of polarization for all incident polarization states. (The reflection Jones matrix of such coated surface is the 2 × 2 identity matrix pre-multiplied by a scalar, hence tanΨ = 1,Δ = 0.) To monitor the deposition of an antireflection coating, the normalized Stokes parameters of obliquely reflected light (e.g. at ϕ =70∘) are measured until predetermined target values of those parameters are detected. This provides a more accurate means of film thickness control than is possible using a micro-balance technique or an intensity reflectance method.

  6. STUDY OF REFLECTION COEFFICIENT DISTRIBUTION FOR ANTI-REFLECTION COATINGS ON SMALL-RADIUS OPTICAL PARTS

    Directory of Open Access Journals (Sweden)

    L. A. Gubanova

    2015-03-01

    Full Text Available The paper deals with findings for the energy reflection coefficient distribution of anti- reflection coating along the surface of optical elements with a very small radius (2-12 mm. The factors influencing the magnitude of the surface area of the optical element, in which the energy reflection coefficient is constant, were detected. The main principles for theoretical models that describe the spectral characteristics of the multilayer interference coatings were used to achieve these objectives. The relative size of the enlightenment area is defined as the ratio of the radius for the optical element surface, where the reflection is less than a certain value, to its radius (ρ/r. The result of research is the following: this size is constant for a different value of the curvature radius for the optical element made of the same material. Its value is determined by the refractive index of material (nm, from which the optical element was made, and the design of antireflection coatings. For single-layer coatings this value is ρ/r = 0.5 when nm = 1.51; and ρ/r = 0.73 when nm = 1.75; for two-layer coatings ρ/r = 0.35 when nm = 1.51 and ρ/r = 0.41 when nm = 1.75. It is shown that with increasing of the material refractive index for the substrate size, the area of minimum reflection coefficient is increased. The paper considers a single-layer, two-layer, three-layer and five-layer structures of antireflection coatings. The findings give the possibility to conclude that equal thickness coverings formed on the optical element surface with a small radius make no equal reflection from the entire surface, and distribution of the layer thickness needs to be looked for, providing a uniform radiation reflection at all points of the spherical surface.

  7. Silicon Nitride Antireflection Coatings for Photovoltaic Cells

    Science.gov (United States)

    Johnson, C.; Wydeven, T.; Donohoe, K.

    1984-01-01

    Chemical-vapor deposition adapted to yield graded index of refraction. Silicon nitride deposited in layers, refractive index of which decreases with distance away from cell/coating interface. Changing index of refraction allows adjustment of spectral transmittance for wavelengths which cell is most effective at converting light to electric current. Average conversion efficiency of solar cells increased from 8.84 percent to 12.63 percent.

  8. Wide-band antireflection coatings; Breitbandige Antireflexbeschichtungen

    Energy Technology Data Exchange (ETDEWEB)

    Gombert, A.; Rommel, M. [Fraunhofer-Inst. fuer Solare Energiesysteme, Freiburg (Germany)

    1998-02-01

    In most cases, solar receivers - from solar collectors to buildings - have a transparent cover. In order to minimize the losses due to reflection, the aim is to find an AR coating which can be used for the broad bandwidth of the solar spectrum. Conventional solutions like multilayer systems with high and low refractive index layers are not suitable. The main problem is to produce layers with very low refractive indices. One solution which was investigated in the past is to synthesize layers with a low effective refractive index due to porosity; i.e. by mixing the bulk material with air on a subwavelength scale. Another possibility to achieve this mixture is given by subwave length surface-relief structures. Porous sol-gel coatings are suited for glass, subwavelength surface-relief structures can be replicated mainly in polymer materials by cheap embossing processes. (orig.) [Deutsch] Nahezu alle solaren Empfaenger sind transparent abgedeckt, z.B. durch Glascheiben. An diesen Abdeckungen wird ein Teil der einfallenden Solarstrahlung reflektiert. Diese Verluste koennen durch reflexionsmindernde Oberflaechen reduziert werden. Antireflexbeschichtungen, die z.B. fuer Brillenglaeser eingesetzt werden, eignen sich nicht fuer solare Entspiegelungen, da ihre spektrale Bandbreite nicht ausreicht. Das Hauptproblem liegt darin, dass Materialien mit sehr niedrigen Brechungsindices, wie sie fuer spektral breitbandige Antireflexbeschichtungen benoetigt werden, nicht verfuegbar sind. Der Ausweg besteht in poroesen Beschichtungen bzw. in einer Oberflaechenstrukturierung. Aufgrund des Luftanteils in der Mischung lassen sich sehr niedrige `effektive` Brechungsindices synthetisieren. Poroese Sol-Gel-Schichten eignen sich insbesondere zur Erhoehung der solaren Transmission von anorganischem Glas. Oberflaechenstrukturen sind aufgrund der Herstellbarkeit durch preisguenstige Praegeprozesse vielversprechend, finden aber derzeit ihre Anwendung ueberwiegend bei polymeren Materialien. (orig.)

  9. Technical and historical overview of the study at Livermore of porous antireflection coatings

    International Nuclear Information System (INIS)

    Milam, D.

    1985-01-01

    The testing program leading to selection of antireflection coatings for the NOVA laser is reviewed. Limiting problems that prevented use of some coating technologies are described, and estimates are made of the current value of pursuing solutions to those problems

  10. Broad Bandwidth Meta-Material Antireflection Coatings for Measurement of the Cosmic Microwave Background

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop broad-band metamaterial antireflection (AR) coatings for the far-infrared and millimeter wave bands. The proposed coating technology could...

  11. Design of multi-layer anti-reflection coating for terrestrial solar panel ...

    Indian Academy of Sciences (India)

    To date, there is no ideal anti-reflection (AR) coating available on solar glass which can effectively transmit the incident light within the visible wavelength range. However, there is a need to develop multifunctional coatingwith superior anti-reflection properties and self-cleaning ability meant to be used for solar glass panels.

  12. Multilayer Antireflection Coating for Triple Junction Solar Cells

    International Nuclear Information System (INIS)

    Zhan Feng; Wang Hai-Li; He Ji-Fang; Wang Juan; Huang She-Song; Ni Hi-Qiao; Niu Zhi-Chuan

    2011-01-01

    According to the theory of optical films, we simulate the reflectivity of antireflection coatings (ARCs) for solar cells of Ga 0.5 In 0.5 P/GaAs/Ge based on an optical transfer matrix. In order to provide sufficient consideration of the refractive index dispersion effect of multilayer ARCs, we use multi-dimensional matrix data for reliable simulation. After the reflection curves are obtained, the effective average reflectance R e is introduced to optimize the film system by minimizing R e . Optimization of single layer (Al 2 O 3 ), double layer (MgF 2 /ZnS) and triple layer (MgF 2 /Al 2 O 3 /ZnS) ARCs is realized by using this method for space and terrestrial applications. Effects of these ARCs are compared after optimization. These theoretical parameters can be used to guide experiments. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  13. Design Multilayer Antireflection Coatings for Terrestrial Solar Cells

    Directory of Open Access Journals (Sweden)

    Feng Zhan

    2014-01-01

    Full Text Available In order to analyze the influence of methods to design antireflection coatings (ARCs on reflectivity of broadband solar cells, we provide detailed analyses about the ARC coupled with a window layer and the refractive index dispersion effect of each layer. By multidimensional matrix data simulation, two methods were employed to measure the composite reflection of a SiO2/ZnS double-layer ARC within the spectral ranges of 300–870 nm (dual junction and 300–1850 nm (triple junction under AM1.5 solar radiation. A comparison study, between the results obtained from the commonly used weighted average reflectance method (WAR and that from the introduced effective average reflectance method (EAR, shows that the optimization of ARC by EAR method is convenient and feasible.

  14. Adhesion of Antireflective Coatings in Multijunction Photovoltaics: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Brock, Ryan; Dauskardt, Reinhold H.; Miller, David C.

    2016-06-16

    The development of a new composite dual cantilever beam (cDCB) thin-film adhesion testing method is reported, which allows the measurement of adhesion on the fragile thin substrates used in multijunction photovoltaics. We address the adhesion of several antireflective coating systems on multijunction cells. By varying interface chemistry and morphology, we demonstrate the ensuing effects on adhesion and help to develop an understanding of how high adhesion can be achieved, as adhesion values ranging from 0.5 J/m2 to 10 J/m2 were measured. Damp Heat (85 degrees C/85% RH) was used to invoke degradation of interfacial adhesion. We show that even with germanium substrates that fracture easily, quantitative measurements of adhesion can still be made at high test yield. The cDCB test is discussed as an important new methodology, which can be broadly applied to any system that makes use of thin, brittle, or otherwise fragile substrates.

  15. Development of Advanced Anti-Reflection Coatings for High Performance Solar Energy Applications, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — MicroLink Devices will increase the efficiency of multi-junction solar cells by designing and demonstrating advanced anti-reflection coatings (ARCs) that will...

  16. Development of Advanced Anti-Reflection Coatings for High Performance Solar Energy Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — MicroLink and its subcontractor Magnolia Solar will develop and demonstrate advanced anti-reflection coating (ARC) designs that will provide a better broadband and...

  17. Sol-gel derived antireflective coatings for silicon

    Energy Technology Data Exchange (ETDEWEB)

    Brinker, C J; Harrington, M S

    1981-08-01

    The preparation of TiO2-SiO2 AR coatings, containing from 30 to 95 mol % TiO2, from alkoxide precursor solutions (titanium tetraethoxide and silicon tetraethoxide) by a sol-gel process is presented. The preparation of the solutions is described, which involves the separate partial hydrolysis of one or both alkoxides prior to their mixing (Yoldas, 1980). The solutions are applied to polished, circular (1 and 2 in. diameter) silicon wafers by a spinning process. The coated wafers are successively heated in air at each of the following temperatures: 200, 300, 350, 400, and 450 C, and optical measurements are performed on them after each heat treatment. The durability of 90 and 95% TiO2 coatings is evaluated in both acidic and basic environments, and reflectivity, film thickness, and refractive index are measured as a function of exposure time. It is shown that sol-gel films applied at 400 C reveal broad regions of antireflectance compared to other titanium-based films.

  18. Applications of antireflection coatings in sonic crystal-based acoustic devices

    International Nuclear Information System (INIS)

    Wang Yun; Deng Ke; Xu Shengjun; Qiu Chunyin; Yang Hai; Liu Zhengyou

    2011-01-01

    The unwanted reflection seriously baffles the practical applications of sonic crystals, such as for various acoustic lenses designed by utilizing the in-band properties of sonic crystals. Herein we introduce the concept of the antireflection coating into the sonic crystal-based devices. The efficiency of such accessorial structures is demonstrated well by an originally high reflection system. Promising perspectives can be anticipated in extending the antireflection coating layers into more general acoustic applications through a flexible design process.

  19. INKJET PRINTING OF ALUMOOXIDE SOL FOR DEPOSITION OF ANTIREFLECTING COATINGS

    Directory of Open Access Journals (Sweden)

    E. A. Eremeeva

    2017-01-01

    Full Text Available Subject of Research. This work describes for the first time the formation of antireflective coating on the base of boehmite phase of AlOOH with low refractive index (1.35 by inkjet printing on the nonporous substrate. This method gives the possibility to increase the contrast of colorful interfering images by 32% obtaining by inkjet printing of titanium dioxide sol. The usage of this technology enables to obtain patterns with wide viewing angle and makes them highly stable. Methods. Traditional sol-gel method with peptizing agents and heating for 90oC was applied for sol synthesis. Then the mixture was under sonic treatment for the obtaining of viscous sol. The viscosity was determined by Brookfield HA/HB viscometer, and the surface tension by Kyowa DY-700 tensiometer. Aluminum oxide ink was deposited on polished slides (26×76 mm2, Paul Marienfeld, Germany, over titanium oxide layer. To print titania ink, we use a desktop office printer Canon Pixma IP 2840 and Dimatix DMP-2831. The thickness of an inkjet AlOOH layer after drying in the air and removal of the solvents did not exceed 150 nm with an RI not less than 1.35 in the entire visible range. Results. The stable colloidal ink was obtained for the first time on the base of aluminum oxide matrix with neutral pH. The rheology was regulated by controlling parameters of sol-gel method in the system of aqueous titanium dioxide sol and by adding ethanol that affects the charge of double electrical layer of disperse phase. The controllable coalesce of drops enables to apply antireflection coating within the thickness accuracy of 10 nm. The morphology of particles and the topology of printed structures were analyzed by optical, scanning electron and atomic-force microscopes. Practical Relevance. We have proposed the approach to obtain colorful, interference patterns using two types of high refractive inks with different refractive indexes. The inkjet printing method opens new opportunities for

  20. Improved HgCdTe detectors with novel antireflection coating

    Science.gov (United States)

    Babu, Sachi R.; Hu, Kelley; Manthripragada, Sridhar; Martineau, Robert J.; Kotecki, C. A.; Peters, F. A.; Burgess, A. S.; Krebs, Danny J.; Mott, David B.; Ewin, Audrey J.; Miles, A.; Nguyen, Trang L.; Shu, Peter K.

    1996-10-01

    The composite infrared spctrometer (CIRS) is an important instrument for the upcoming Cassini mission for sensing infrared (IR) radiation from the Saturanian planetary system. We have delivered a linear, ten element, mercury cadmium telluride (HgCdTe) photoconductive detector array for use on focal plane 3 (FP3), which is responsible for detecting radiation from the 9.1 micrometer to 16.6 micrometer wavelength range. Reliable HgCdTe detectors require robust passivation, a low-stress zinc sulfide (ZnS) anti-reflection (AR) coating with good adhesion, and a proper optical cavity design to smooth out the resonance in the detector spectral response. During the development of CIRS flight array, we have demonstrated the potential of using an in-situ interfacial layer, such as SiN(subscript x), between ZnS and the anodic oxide. Such an interfacial layer drastically improves the adhesion between the ZnS and oxide, without degrading the minority carrier lifetime. We have also demonstrated the feasibility of applying a SiN(subscript x) 'rain coat' layer over the ZnS to prevent moisture and other chemicals from attacking the AR coating, thus improving the long term reliability. This also enables device operation in a hazardous environment. The alumina/epoxy/HgCdTe/oxide/ZnS structure is a complicated multi-cavity optical system. We have developed an extensive device simulation, which enables us to make the optimal choice of individual cavity thickness for minimizing the resonance and maximizing the quantum efficiency. We have also used 0.05 micrometer alumina powder loaded epoxy to minimize the reflections at the epoxy/HgCdTe interface, thus minimizing the resonance.

  1. Wide band antireflective coatings Al2O3 / HfO2 / MgF2 for UV region

    Science.gov (United States)

    Winkowski, P.; Marszałek, Konstanty W.

    2013-07-01

    Deposition technology of the three layers antireflective coatings consists of hafnium compound are presented in this paper. Oxide films were deposited by means of e-gun evaporation in vacuum of 5x10-5 mbar in presence of oxygen and fluoride films by thermal evaporation. Substrate temperature was 250°C. Coatings were deposited onto optical lenses made from quartz glass (Corning HPFS). Thickness and deposition rate were controlled by thickness measuring system Inficon XTC/2. Simulations leading to optimization of thickness and experimental results of optical measurements carried during and after deposition process were presented. Physical thickness measurements were made during deposition process and were equal to 43 nm/74 nm/51 nm for Al2O3 / HfO2 / MgF2 respectively. Optimization was carried out for ultraviolet region from 230nm to the beginning of visible region 400 nm. In this region the average reflectance of the antireflective coating was less than 0.5% in the whole range of application.

  2. Selective dry etching of silicon containing anti-reflective coating

    Science.gov (United States)

    Sridhar, Shyam; Nolan, Andrew; Wang, Li; Karakas, Erdinc; Voronin, Sergey; Biolsi, Peter; Ranjan, Alok

    2018-03-01

    Multi-layer patterning schemes involve the use of Silicon containing Anti-Reflective Coating (SiARC) films for their anti-reflective properties. Patterning transfer completion requires complete and selective removal of SiARC which is very difficult due to its high silicon content (>40%). Typically, SiARC removal is accomplished through a non-selective etch during the pattern transfer process using fluorine containing plasmas, or an ex-situ wet etch process using hydrofluoric acid is employed to remove the residual SiARC, post pattern transfer. Using a non-selective etch may result in profile distortion or wiggling, due to distortion of the underlying organic layer. The drawbacks of using wet etch process for SiARC removal are increased overall processing time and the need for additional equipment. Many applications may involve patterning of active structures in a poly-Si layer with an underlying oxide stopping layer. In such applications, SiARC removal selective to oxide using a wet process may prove futile. Removing SiARC selectively to SiO2 using a dry etch process is also challenging, due to similarity in the nature of chemical bonds (Si - O) in the two materials. In this work, we present highly selective etching of SiARC, in a plasma driven by a surface wave radial line slot antenna. The first step in the process involves an in-situ modification of the SiARC layer in O2 plasma followed by selective etching in a NF3/H2 plasma. Surface treatment in O2 plasma resulted in enhanced etching of the SiARC layer. For the right processing conditions, in-situ NF3/H2 dry etch process demonstrated selectivity values greater than 15:1 with respect to SiO2. The etching chemistry, however, was sensitive to NF3:H2 gas ratio. For dilute NF3 in H2, no SiARC etching was observed. Presumably, this is due to the deposition of ammonium fluorosilicate layer that occurs for dilute NF3/H2 plasmas. Additionally, challenges involved in selective SiARC removal (selective to SiO2, organic

  3. Sprayed and Spin-Coated Multilayer Antireflection Coating Films for Nonvacuum Processed Crystalline Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Abdullah Uzum

    2017-01-01

    Full Text Available Using the simple and cost-effective methods, spin-coated ZrO2-polymer composite/spray-deposited TiO2-compact multilayer antireflection coating film was introduced. With a single TiO2-compact film on the surface of a crystalline silicon wafer, 5.3% average reflectance (the reflectance average between the wavelengths of 300 nm and 1100 nm was observed. Reflectance decreased further down to 3.3% after forming spin-coated ZrO2 on the spray-deposited TiO2-compact film. Silicon solar cells were fabricated using CZ-Si p-type wafers in three sets: (1 without antireflection coating (ARC layer, (2 with TiO2-compact ARC film, and (3 with ZrO2-polymer composite/TiO2-compact multilayer ARC film. Conversion efficiency of the cells improved by a factor of 0.8% (from 15.19% to 15.88% owing to the multilayer ARC. Jsc was improved further by 2 mA cm−2 (from 35.3 mA cm−2 to 37.2 mA cm−2 when compared with a single TiO2-compact ARC.

  4. Solar cells based upon multicrystalline Si with DLC antireflection and passivating coatings

    International Nuclear Information System (INIS)

    Klyui, N.; Litovchenko, V.; Neselevska, L.; Kostylyov, V.; Sarikov, A.; Taraschenko, N.; Kittler, M.; Seifert, W.

    2006-01-01

    The characteristics of multicrystalline Si solar cells covered by diamond-like carbon (DLC) antireflection coatings been experimentally studied. It has been shown that this kind of coating provides a significant increase of the efficiency of solar cells mainly due to the increase of the short-circuit current density. The effects of antireflection and of the surface and bulk passivation on the SC current-voltage characteristics due to the DLC deposition have been investigated theoretically. Physical mechanisms underlying the observed effects have been proposed

  5. The hydrophobic and omnidirectional antireflection coating of SiO2 nanospheres with C18-TEOS

    Science.gov (United States)

    Hsu, Cheng-Chih; Lan, Wen-Lin; Chen, Nien-Po; Wu, Chyan-Chyi

    2014-06-01

    This paper demonstrates the antireflection coating of SiO2 nanospheres applied to cover glass by using the optimal spin-coating method. Because of the hydrolysis and condensation reactions between the SiO2 nanosphere antireflection (AR) coating and n-octadecyltriethoxysilane solution (C18-TEOS), the contact angle of the AR coating with hydrophobic treatment is improved approximately 38%, and the moisture-resistance remains unchanged, which preserved similar transmittance for six weeks. Furthermore, the AR coating with hydrophobic treatment exhibits approximately 3% and 7% improvement in the transmittance at normal and oblique incidence, respectively. The hydrophobic and omnidirectional AR coating with nanoscale SiO2 particles can be fabricated using the proposed simple and economical method.

  6. Metasurface-based anti-reflection coatings at optical frequencies

    Science.gov (United States)

    Monti, Alessio; Alù, Andrea; Toscano, Alessandro; Bilotti, Filiberto

    2018-05-01

    In this manuscript, we propose a metasurface approach for the reduction of electromagnetic reflection from an arbitrary air‑dielectric interface. The proposed technique exploits the exotic optical response of plasmonic nanoparticles to achieve complete cancellation of the field reflected by a dielectric substrate by means of destructive interference. Differently from other, earlier anti-reflection approaches based on nanoparticles, our design scheme is supported by a simple transmission-line formulation that allows a closed-form characterization of the anti-reflection performance of a nanoparticle array. Furthermore, since the working principle of the proposed devices relies on an average effect that does not critically depend on the array geometry, our approach enables low-cost production and easy scalability to large sizes. Our theoretical considerations are supported by full-wave simulations confirming the effectiveness of this design principle.

  7. Scale-up of Nano-Engineered Anti-Reflection Coating Process for Large Plastic Optics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In a recently completed NASA SBIR program, Agiltron and the Massachusetts Institute of Technology developed a novel nanoporous UV anti-reflection coating technology...

  8. Effect of sol aging time on the anti-reflective properties of silica coatings templated with phosphoric acid

    Directory of Open Access Journals (Sweden)

    Wen Wen

    Full Text Available Silica anti-reflective coatings have been prepared by a sol–gel dip-coating process using the sol containing phosphoric acid as a pore-forming template. The effect of the aging time of the sol on the anti-reflective properties has been investigated. The surface topography of the silica AR coatings has been characterized. With increasing sol aging time, more over-sized pores larger than 100 nm are formed in the silica coatings. These could act as scattering centers, scattering visible light and thereby lowering transmittance. The optimal aging time was identified as 1 day, and the corresponding silica coatings showed a maximum transmittance of 99.2%, representing an 8% increase compared to the bare glass substrate. Keywords: Thin films, Anti-reflective coatings, Aging, Dip-coating, Sol–gel preparation

  9. Moisture resistant and anti-reflection optical coatings produced by plasma polymerization of organic compounds

    Science.gov (United States)

    Hollahan, J. R.; Wydeven, T.

    1975-01-01

    The need for protective coatings on critical optical surfaces, such as halide crystal windows or lenses used in spectroscopy, has long been recognized. It has been demonstrated that thin, one micron, organic coatings produced by polymerization of flourinated monomers in low temperature gas discharge (plasma) exhibit very high degrees of moisture resistence, e.g., hundreds of hours protection for cesium iodide vs. minutes before degradation sets in for untreated surfaces. The index of refraction of these coatings is intermediate between that of the halide substrate and air, a condition for anti-reflection, another desirable property of optical coatings. Thus, the organic coatings not only offer protection, but improved transmittance as well. The polymer coating is non-absorbing over the range 0.4 to 40 microns with an exception at 8.0 microns, the expected absorption for C-F bonds.

  10. Near zero reflection by nanostructured anti-reflection coating design for Si substrates

    Science.gov (United States)

    Al-Fandi, Mohamed; Makableh, Yahia F.; Khasawneh, Mohammad; Rabady, Rabi

    2018-05-01

    The nanostructure design of near zero reflection coating for Si substrates by using ZnO Nanoneedles (ZnONN) is performed and optimized for the visible spectral range. The design investigates the ZnONN tip to body ratio effect on the anti-reflection coating properties. Different tip to body ratios are used on Si substrates. Around zero reflection is achieved by the Nanoneedles structure design presented in this work, leading to minimal reflection losses from the Si surface. The current design evolves a solution to optical losses and surface contamination effects associated with Si solar cells.

  11. Anti-reflective polymer-nanocomposite coatings fabricated by RIR-MAPLE

    Science.gov (United States)

    Singaravalu, S.; Mayo, D. C.; Park, H. K.; Schriver, K. E.; Haglund, R. F.

    2013-02-01

    There is increasing demand for functional polymeric optical coatings for plastic substrates. In the case of anti-reflective (AR) coatings, this is challenging because polymers exhibit a relatively narrow range of refractive indices. We synthesized a four-layer AR stack using hybrid polymer:nanoparticle materials deposited by resonant infrared matrixassisted pulsed laser evaporation (RIR-MAPLE). An Er:YAG laser ablated frozen solutions of a high-index composite containing TiO2 nanoparticles and PMMA, alternating with a low-index solution of PMMA. The optimized AR coatings, with thicknesses calculated using commercial software, yielded a coating for polycarbonate with relative transmission over 94%, scattering less than 5% and a reflection coefficient below 0.8% across the visible range.

  12. Performance of "Moth Eye" Anti-Reflective Coatings for Solar Cell Applications

    Energy Technology Data Exchange (ETDEWEB)

    Clark, E.; Kane, M.; Jiang, P.

    2011-03-14

    An inexpensive, effective anti-reflective coating (ARC) has been developed at the University of Florida to significantly enhance the absorption of light by silicon in solar cells. This coating has nano-scale features, and its microstructure mimics that of various night active insects (e.g. a moth's eye). It is a square array of pillars, each about 700 nm high and having a diameter of about 300 nm. Samples of silicon having this coating were exposed either to various combinations of either elevated temperature and humidity or to gamma irradiation ({sup 60}Co) at the Savannah River National Laboratory, or to a broad spectrum ultraviolet light and to a 532 nm laser light at the University of Florida. The anti-reflective properties of the coatings were unaffected by any of these environmental stresses, and the microstructure of the coating was also unaffected. In fact, the reflectivity of the gamma irradiated ARC became lower (advantageous for solar cell applications) at wavelengths between 400 and 1000 nm. These results show that this coating is robust and should be tested in actual systems exposed to either weather or a space environment. Structural details of the ARCs were studied to optimize their performance. Square arrays performed better than hexagonal arrays - the natural moth-eye coating is indeed a square array. The optimal depth of the templated nanopillars in the ARC was investigated. A wet etching technology for ARC formation was developed that would be less expensive and much faster than dry etching. Theoretical modeling revealed that dimple arrays should perform better than nipple arrays. A method of fabricating both dimple and nipple arrays having the same length was developed, and the dimple arrays performed better than the nipple arrays, in agreement with the modeling. The commercial viability of the technology is quite feasible, since the technology is scalable and inexpensive. This technology is also compatible with current industrial

  13. Synthesis and Characterization of Antireflective ZnO Nanoparticles Coatings Used for Energy Improving Efficiency of Silicone Solar Cells

    Science.gov (United States)

    Pîslaru-Dǎnescu, Lucian; Chitanu, Elena; El-Leathey, Lucia-Andreea; Marinescu, Virgil; Marin, Dorian; Sbârcea, Beatrice-Gabriela

    2018-03-01

    The paper proposes a new and complex process for the synthesis of ZnO nanoparticles for antireflective coating corresponding to silicone solar cells applications. The process consists of two major steps: preparation of seed layer and hydrothermal growth of ZnO nanoparticles. Due to the fact that the seed layer morphology influences the ZnO nanoparticles proprieties, the process optimization of the seed layer preparation is necessary. Following the hydrothermal growth of the ZnO nanoparticles, antireflective coating of silicone solar cells is achieved. After determining the functional parameters of the solar cells provided either with glass or with ZnO, it is concluded that all the parameters values are superior in the case of solar cells with ZnO antireflection coating and are increasing along with the solar irradiance.

  14. Atomic Layer Deposition of Chemical Passivation Layers and High Performance Anti-Reflection Coatings on Back-Illuminated Detectors

    Science.gov (United States)

    Hoenk, Michael E. (Inventor); Greer, Frank (Inventor); Nikzad, Shouleh (Inventor)

    2014-01-01

    A back-illuminated silicon photodetector has a layer of Al2O3 deposited on a silicon oxide surface that receives electromagnetic radiation to be detected. The Al2O3 layer has an antireflection coating deposited thereon. The Al2O3 layer provides a chemically resistant separation layer between the silicon oxide surface and the antireflection coating. The Al2O3 layer is thin enough that it is optically innocuous. Under deep ultraviolet radiation, the silicon oxide layer and the antireflection coating do not interact chemically. In one embodiment, the silicon photodetector has a delta-doped layer near (within a few nanometers of) the silicon oxide surface. The Al2O3 layer is expected to provide similar protection for doped layers fabricated using other methods, such as MBE, ion implantation and CVD deposition.

  15. Titanium dioxide antireflective coating for silicon solar cells by spinning technique

    Energy Technology Data Exchange (ETDEWEB)

    Murozono, M; Kitamura, S

    1982-01-01

    Antireflective (AR) TiO2 films for Si solar cells are presently obtained by coating a solution that is derived from organotitanium compounds (with an acetylacetone ligand and an ethanol solvent) on the Si surface using a spinning technique, and then firing at high temperature. AR film thickness can be controlled by up to 1200 A by changing solution concentration and spin speed. Si solar cells with these AR films exhibit as much as a 50 percent improvement in conversion efficiency over uncoated cells. 12 references.

  16. Antireflective bilayer coatings based on Al2O3 film for UV region

    OpenAIRE

    Marszałek Konstanty; Winkowski Paweł; Marszałek Marta

    2015-01-01

    Bilayer antireflective coatings consisting of aluminium oxide Al2O3/MgF2 and Al2O3/SiO2 are presented in this paper. Oxide films were deposited by means of e-gun evaporation in vacuum of 5 × 10-3 Pa in the presence of oxygen, and magnesium fluoride was prepared by thermal evaporation on heated optical lenses made from quartz glass (Corning HPFS). Substrate temperature was maintained at 250 _C during the deposition. Thickness and deposition rate were controlled with a thickness measuring syste...

  17. Development of processing procedures for advanced silicon solar cells. [antireflection coatings and short circuit currents

    Science.gov (United States)

    Scott-Monck, J. A.; Stella, P. M.; Avery, J. E.

    1975-01-01

    Ten ohm-cm silicon solar cells, 0.2 mm thick, were produced with short circuit current efficiencies up to thirteen percent and using a combination of recent technical advances. The cells were fabricated in conventional and wraparound contact configurations. Improvement in cell collection efficiency from both the short and long wavelengths region of the solar spectrum was obtained by coupling a shallow junction and an optically transparent antireflection coating with back surface field technology. Both boron diffusion and aluminum alloying techniques were evaluated for forming back surface field cells. The latter method is less complicated and is compatible with wraparound cell processing.

  18. Antireflectance coating on shielding window glasses using glacial acetic acid at ambient temperature

    International Nuclear Information System (INIS)

    Sathi Sasidharan, N.; Deshingkar, D.S.; Wattal, P.K.

    2006-01-01

    High density lead glasses having thickness of several centimeters and large dimensions are used as shielding windows in hot cells. To improve visibility, the reflection of light from its optically polished surfaces needs to be minimized to improve transmission as absorption of light in the thick glasses can not be avoided. Antireflectance coating of a material having low refractive index is required for this purpose. Selective leaching of lead at ambient temperature in glacial acetic acid develops a silica rich leached layer on glass surface. Since silica has low refractive index, the leached layer serves as antireflectance coating. Two optically polished discs of shielding window glasses were leached in glacial acetic acid at ambient temperature for 2, 5 and 10 days and their reflectance and transmittance spectra were taken to find effect of leaching. For transparent glass transmittance could be improved from 78.76% to 85.31% after 10 days leaching. Reflectance from the glass could be decreased from 12.48 to 11.67%. For coloured glass transmittance improved from 87.77% to 88.24% after 5 days leaching while reflectance decreased from 12.28% to 5.6% during same period. Based on data generated, 10 days leaching time is recommended for developing anti reflectance coating on transparent shielding window glass and 5 days for coloured shielding window glass. The procedure can be used for shielding windows of any dimensions by fabrication a PVC tank of slightly high dimensions and filling with acetic acid (author)

  19. Development of Nanostructured Antireflection Coatings for Infrared and Electro-Optical Systems

    Directory of Open Access Journals (Sweden)

    Gopal G. Pethuraja

    2017-07-01

    Full Text Available Electro-optic infrared technologies and systems operating from ultraviolet (UV to long-wave infrared (LWIR spectra are being developed for a variety of defense and commercial systems applications. Loss of a significant portion of the incident signal due to reflection limits the performance of electro-optic infrared (IR sensing systems. A critical technology being developed to overcome this limitation and enhance the performance of sensing systems is advanced antireflection (AR coatings. Magnolia is actively involved in the development and advancement of nanostructured AR coatings for a wide variety of defense and commercial applications. Ultrahigh AR performance has been demonstrated for UV to LWIR spectral bands on various substrates. The AR coatings enhance the optical transmission through optical components and devices by significantly minimizing reflection losses, a substantial improvement over conventional thin-film AR coating technologies. Nanostructured AR coatings have been fabricated using a nanomanufacturable self-assembly process on substrates that are transparent for a given spectrum of interest ranging from UV to LWIR. The nanostructured multilayer structures have been designed, developed and optimized for various optoelectronic applications. The optical properties of optical components and sensor substrates coated with AR structures have been measured and the process parameters fine-tuned to achieve a predicted high level of performance. In this paper, we review our latest work on high quality nanostructure-based AR coatings, including recent efforts on the development of nanostructured AR coatings on IR substrates.

  20. Novel conformal organic antireflective coatings for advanced I-line lithography

    Science.gov (United States)

    Deshpande, Shreeram V.; Nowak, Kelly A.; Fowler, Shelly; Williams, Paul; Arjona, Mikko

    2001-08-01

    Flash memory chips are playing a critical role in semiconductor devices due to increased popularity of hand held electronic communication devices such as cell phones and PDAs (personal Digital Assistants). Flash memory offers two primary advantages in semiconductor devices. First, it offers flexibility of in-circuit programming capability to reduce the loss from programming errors and to significantly reduce commercialization time to market for new devices. Second, flash memory has a double density memory capability through stacked gate structures which increases the memory capability and thus saves significantly on chip real estate. However, due to stacked gate structures the requirements for manufacturing of flash memory devices are significantly different from traditional memory devices. Stacked gate structures also offer unique challenges to lithographic patterning materials such as Bottom Anti-Reflective Coating (BARC) compositions used to achieve CD control and to minimize standing wave effect in photolithography. To be applicable in flash memory manufacturing a BARC should form a conformal coating on high topography of stacked gate features as well as provide the normal anti-reflection properties for CD control. In this paper we report on a new highly conformal advanced i-line BARC for use in design and manufacture of flash memory devices. Conformal BARCs being significantly thinner in trenches than the planarizing BARCs offer the advantage of reducing BARC overetch and thus minimizing resist thickness loss.

  1. Layer-by-Layer-Assembled High-Performance Broadband Antireflection Coatings

    KAUST Repository

    Shimomura, Hiroomi

    2010-03-24

    Nanoparticles are indispensable ingredients of solution-processed optical, dielectric, and catalytic thin films. Although solution-based methods are promising low-cost alternatives to vacuum methods, they can have significant limitations. Coating uniformity, thickness control, roughness control, mechanical durability, and incorporation of a diverse set of functional organic molecules into nanoparticle thin films are major challenges. We have used the electrostatic layer-by-layer assembly technique to make uniform, conformal multistack nanoparticle thin films for optical applications with precise thickness control over each stack. Two particularly sought-after optical applications are broadband antireflection and structural color. The effects of interstack and surface roughness on optical properties of these constructs (e.g., haze and spectral response) have been studied quantitatively using a combination of Fourier-transform methods and atomic force microscopy measurements. Deconvoluting root-mean-square roughness into its large-, intermediate-, and small-scale components enables enhanced optical simulations. A 4-stack broadband antireflection coating (<0.5% average reflectance in the visible range, and 0.2% haze) composed of alternating high-index (n ≈ 1.96) and low-index (n ≈ 1.28) stacks has been made on glass substrate. Films calcinated at 550 °C endure a one-hour-long cloth cleaning test under 100 kPa normal stress. © 2010 American Chemical Society.

  2. Bright Single-Photon Sources Based on Anti-Reflection Coated Deterministic Quantum Dot Microlenses

    Directory of Open Access Journals (Sweden)

    Peter Schnauber

    2015-12-01

    Full Text Available We report on enhancing the photon-extraction efficiency (PEE of deterministic quantum dot (QD microlenses via anti-reflection (AR coating. The AR-coating deposited on top of the curved microlens surface is composed of a thin layer of Ta2O5, and is found to effectively reduce back-reflection of light at the semiconductor-vacuum interface. A statistical analysis of spectroscopic data reveals, that the AR-coating improves the light out-coupling of respective microlenses by a factor of 1.57 ± 0.71, in quantitative agreement with numerical calculations. Taking the enhancement factor into account, we predict improved out-coupling of light with a PEE of up to 50%. The quantum nature of emission from QDs integrated into AR-coated microlenses is demonstrated via photon auto-correlation measurements revealing strong suppression of two-photon emission events with g(2(0 = 0.05 ± 0.02. As such, these bright non-classical light sources are highly attractive with respect to applications in the field of quantum cryptography.

  3. Fabrication of Antireflection Nanodiamond Particle Film by the Spin Coating Deposition Technique

    Directory of Open Access Journals (Sweden)

    Chii-Ruey Lin

    2014-01-01

    Full Text Available Diamond-based antireflective (AR coatings were fabricated using a spin coating of diamond suspension at room temperature as nucleation enhancement procedure and microwave plasma enhanced chemical vapour deposition. Various working pressures were used to investigate their effect on the optical characterization of the as-deposited diamond films. Scanning electron microscopy (SEM and atomic forced microscopy (AFM were employed to analyze the surface properties of the diamond films. Raman spectra and transmission electron microscopy (TEM also were used for analysis of the microstructure of the films. The results showed that working pressure had a significant effect on thickness, surface roughness, and wettability of the as-deposited diamond films. Deposited under 35 Torr or working pressure, the film possessed a low surface roughness of 13.8 nm and fine diamond grain sizes of 35 nm. Reflectance measurements of the films also were carried out using UV-Vis spectrometer and revealed a low reflectance value of the diamond films. The achievement demonstrated feasibility of the proposed spin-coating procedure for large scale production and thus opens up a prospect application of diamond film as an AR coating in industrial optoelectronic device.

  4. An experimental study of antireflective coatings in Ge light detectors for scintillating bolometers

    Directory of Open Access Journals (Sweden)

    Mancuso M.

    2014-01-01

    Full Text Available Luminescent bolometers are double-readout devices able to measure simultaneously the phonon and the light yields after a particle interaction in the detector. This operation allows in some cases to tag the type of the interacting quantum, crucial issue for background control in rare event experiments such as the search for neutrinoless double beta decay and for interactions of particle dark matter candidates. The light detectors used in the LUCIFER and LUMINEU searches (projects aiming at the study of the double beta interesting candidates 82Se and 100Mo using ZnSe and ZnMoO4 scintillating bolometers consist of hyper-pure Ge thin slabs equipped with NTD thermistors. A substantial sensitivity improvement of the Ge light detectors can be obtained applying a proper anti-reflective coatings on the Ge side exposed to the luminescent bolometer. The present paper deals with the investigation of this aspect, proving and quantifying the positive effect of a SiO2 and a SiO coating and setting the experimental bases for future tests of other coating materials. The results confirm that an appropriate coating procedure helps in improving the sensitivity of bolometric light detectors by an important factor (in the range 20% – 35% and needs to be included in the recipe for the development of an optimized radio-pure scintillating bolometer.

  5. An experimental study of antireflective coatings in Ge light detectors for scintillating bolometers

    Science.gov (United States)

    Mancuso, M.; Beeman, J. W.; Giuliani, A.; Dumoulin, L.; Olivieri, E.; Pessina, G.; Plantevin, O.; Rusconi, C.; Tenconi, M.

    2014-01-01

    Luminescent bolometers are double-readout devices able to measure simultaneously the phonon and the light yields after a particle interaction in the detector. This operation allows in some cases to tag the type of the interacting quantum, crucial issue for background control in rare event experiments such as the search for neutrinoless double beta decay and for interactions of particle dark matter candidates. The light detectors used in the LUCIFER and LUMINEU searches (projects aiming at the study of the double beta interesting candidates 82Se and 100Mo using ZnSe and ZnMoO4 scintillating bolometers) consist of hyper-pure Ge thin slabs equipped with NTD thermistors. A substantial sensitivity improvement of the Ge light detectors can be obtained applying a proper anti-reflective coatings on the Ge side exposed to the luminescent bolometer. The present paper deals with the investigation of this aspect, proving and quantifying the positive effect of a SiO2 and a SiO coating and setting the experimental bases for future tests of other coating materials. The results confirm that an appropriate coating procedure helps in improving the sensitivity of bolometric light detectors by an important factor (in the range 20% - 35%) and needs to be included in the recipe for the development of an optimized radio-pure scintillating bolometer.

  6. Titanium dioxide antireflection coating for silicon solar cells by spray deposition

    Science.gov (United States)

    Kern, W.; Tracy, E.

    1980-01-01

    A high-speed production process is described for depositing a single-layer, quarter-wavelength thick antireflection coating of titanium dioxide on metal-patterned single-crystal silicon solar cells for terrestrial applications. Controlled atomization spraying of an organotitanium solution was selected as the most cost-effective method of film deposition using commercial automated equipment. The optimal composition consists of titanium isopropoxide as the titanium source, n-butyl acetate as the diluent solvent, sec-butanol as the leveling agent, and 2-ethyl-1-hexanol to render the material uniformly depositable. Application of the process to the coating of circular, large-diameter solar cells with either screen-printed silver metallization or with vacuum-evaporated Ti/Pd/Ag metallization showed increases of over 40% in the electrical conversion efficiency. Optical characteristics, corrosion resistance, and several other important properties of the spray-deposited film are reported. Experimental evidence indicates a wide tolerance in the coating thickness upon the overall efficiency of the cell. Considerations pertaining to the optimization of AR coatings in general are discussed, and a comprehensive critical survey of the literature is presented.

  7. Highly transparent triboelectric nanogenerator for harvesting water-related energy reinforced by antireflection coating

    Science.gov (United States)

    Liang, Qijie; Yan, Xiaoqin; Gu, Yousong; Zhang, Kui; Liang, Mengyuan; Lu, Shengnan; Zheng, Xin; Zhang, Yue

    2015-03-01

    Water-related energy is an inexhaustible and renewable energy resource in our environment, which has huge amount of energy and is not largely dictated by daytime and sunlight. The transparent characteristic plays a key role in practical applications for some devices designed for harvesting water-related energy. In this paper, a highly transparent triboelectric nanogenerator (T-TENG) was designed to harvest the electrostatic energy from flowing water. The instantaneous output power density of the T-TENG is 11.56 mW/m2. Moreover, with the PTFE film acting as an antireflection coating, the maximum transmittance of the fabricated T-TENG is 87.4%, which is larger than that of individual glass substrate. The T-TENG can be integrated with silicon-based solar cell, building glass and car glass, which demonstrates its potential applications for harvesting waste water energy in our living environment and on smart home system and smart car system.

  8. Anti-reflecting and passivating coatings for silicon solar cells on a basis of SO2 and TiO2 layers

    International Nuclear Information System (INIS)

    Taurbaev, T.I.; Nikulin, V.Eh.; Shorin, V.F.; Topanov, B.G.; Dikhanbaev, K.K.

    2002-01-01

    An analysis of influence of passivating layer on performance of anti-reflection coating of solar cells is carried out. The introduction of passivating SiO 2 layer between a frontal surface of the solar cell and TiO 2 +SiO 2 anti-reflection coating increase total reflection. If a thickness of a passivating layer no more than 20 Angstrom an increase of reflection does not exceed 0.5 %. However, for effective passivation the thickness of the passivating layer has to be within 100-1000 Angstrom region, thus the interference contribution of the passivating layer becomes essential and the AC is necessary to calculate as triple system SiO 2 -TiO 2 -SiO 2 . Such the three layers system ensuring average coefficient of reflection less of 3.5 % in a range 0.4-1.1 μm if the thickness of passivating SiO 2 layer no more 200 Angstrom. For solar cells with passivating SiO 2 layer thickness of 100 Angstrom and protective glass of non-interference thickness the single layer AC from TiO 2 allows to receive average value of reflection coefficient for a spectral range 0.4-1.1 μm no more than 9.5 %. The introduction of two additional layers SiO 2 and TiO 2 allows to reduce this value on 2.0-3.0 %. The comparison of calculation and experimental results is given. (author)

  9. MULTI-ZONE ANTIREFLECTION COATING ON A SUBSTRATE MADE OF OPTICAL ZINC SULPHIDE

    Directory of Open Access Journals (Sweden)

    T. D. Tan

    2014-01-01

    Full Text Available The paper deals with creation technique for a multi-zone antireflection coating on a substrate made of the optical zinc sulphide ZnS. The coating effectively operates simultaneously in the following spectral ranges: visible region of 450 - 700 nm, in the near infrared region of 1000 - 1100 nm, at the wavelength of 1.55 μm, and in the mid-infrared (IR spectrum of 3 - 5 microns. Reflection coefficient in the range of 450 - 700 nm is not more than 2%, in the range of 1000 - 1100 nm is less than 0.5%, in the range of 1500 - 1700 nm is close to 1.5% and in the range of 3 - 5 μm is equal to 0.6%. Analysis results of the deviation impact in the thickness of layers on the value changing of the energy reflection coefficient in the considered areas are given. Deviation in the thickness of the layer, contiguous with the air, is shown to have the greatest effect on the spectral characteristics of the obtained coating. Refractive index deviation for this layer influences the magnitude of the residual reflection.

  10. Broadband anti-reflective and water-repellent coatings on glass substrates for self-cleaning photovoltaic cells

    International Nuclear Information System (INIS)

    Li, Xiaoyu; He, Junhui; Liu, Weiyi

    2013-01-01

    Graphical abstract: High performance broadband antireflective and water-repellent coatings were fabricated on glass substrates, which can improve the short-circuit current of solar cells as much as 6.6% in comparison with glass substrates without the coatings. - Highlights: • Broadband anti-reflective and water-repellent coatings were fabricated. • Transmittance increased to 99.0%, significantly higher than that of commercial solar glasses. • The performance of standard solar cells with the AR coating was enhanced as much as 6.6%. - Abstract: High performance broadband antireflective (AR) and water-repellent coatings were fabricated on glass substrates by assembly of silica nanoparticles and polyelectrolytes via the layer-by-layer (LbL) assembly technique, followed by calcination and hydrophobic modification. A porous poly(diallyladimethylammonium chloride) (PDDA)/20 nm SiO 2 nanoparticles (S-20) multilayer coating with AR property was prepared first. The maximum transmittance is as high as 99.0%, while that of the glass substrate is only 91.3%. After calcination and hydrophobic modification, the coating became water-repellent while maintaining the good AR property. Such water-repellent AR coatings can improve the short-circuit current of solar cells as much as 6.6% in comparison with glass substrates without the coatings. Scanning electron microscopy (SEM) was used to observe the morphology and thickness of coatings. Transmission spectra and reflection spectra were characterized by UV–vis spectrophotometer. The surface wettability was studied by a contact angle/interface system

  11. Application of CBD-Zinc Sulfide Film as an Antireflection Coating on Very Large Area Multicrystalline Silicon Solar Cell

    Directory of Open Access Journals (Sweden)

    U. Gangopadhyay

    2007-01-01

    Full Text Available The low-cost chemical bath deposition (CBD technique is used to prepare CBD-ZnS films as antireflective (AR coating for multicrystalline silicon solar cells. The uniformity of CBD-ZnS film on large area of textured multicrystalline silicon surface is the major challenge of CBD technique. In the present work, attempts have been made for the first time to improve the rate of deposition and uniformity of deposited film by controlling film stoichiometry and refractive index and also to minimize reflection loss by proper optimization of molar percentage of different chemical constituents and deposition conditions. Reasonable values of film deposition rate (12.13 Å′/min., good film uniformity (standard deviation <1, and refractive index (2.35 along with a low percentage of average reflection (6-7% on a textured mc-Si surface are achieved with proper optimization of ZnS bath. 12.24% efficiency on large area (125 mm × 125 mm multicrystalline silicon solar cells with CBD-ZnS antireflection coating has been successfully fabricated. The viability of low-cost CBD-ZnS antireflection coating on large area multicrystalline silicon solar cell in the industrial production level is emphasized.

  12. Non-Vacuum Processed Polymer Composite Antireflection Coating Films for Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Abdullah Uzum

    2016-08-01

    Full Text Available A non-vacuum processing method for preparing polymer-based ZrO2/TiO2 multilayer structure antireflection coating (ARC films for crystalline silicon solar cells by spin coating is introduced. Initially, ZrO2, TiO2 and surface deactivated-TiO2 (SD-TiO2 based films were examined separately and the effect of photocatalytic properties of TiO2 film on the reflectivity on silicon surface was investigated. Degradation of the reflectance performance with increasing reflectivity of up to 2% in the ultraviolet region was confirmed. No significant change of the reflectance was observed when utilizing SD-TiO2 and ZrO2 films. Average reflectance (between 300 nm–1100 nm of the silicon surface coated with optimized polymer-based ZrO2 single or ZrO2/SD-TiO2 multilayer composite films was decreased down to 6.5% and 5.5%, respectively. Improvement of photocurrent density (Jsc and conversion efficiency (η of fabricated silicon solar cells owing to the ZrO2/SD-TiO2 multilayer ARC could be confirmed. The photovoltaic properties of Jsc, the open-circuit photo voltage (VOC, the fill factor (FF, and the η were 31.42 mA cm−2, 575 mV, 71.5% and 12.91%. Efficiency of the solar cells was improved by the ZrO2-polymer/SD-TiO2 polymer ARC composite layer by a factor of 0.8% with an increase of Jsc (2.07 mA cm−2 compared to those of fabricated without the ARC.

  13. Design of a new bottom antireflective coating composition for KrF resist

    Science.gov (United States)

    Mizutani, Kazuyoshi; Momota, Makoto; Aoai, Toshiaki; Yagihara, Morio

    1999-06-01

    A study for a new organic bottom antireflective coating (BARC) composition is described. A structural design of a light-absorbing dye was most important because dye structure not only plays a role in eliminating reflection from a substrate but also shows influence on dry etch rate of BARC material to a considerable extent. For example, an anthracene moiety with large absorption at 248 nm had undesirable dry etch resistance. 3-Hydroxy-2-naphthoic acid moiety was found to be one of suitable dyes for KrF BARC compositions, and the polymer bearing the dye showed enough absorbance and good erodability in dry etch. The BARC polymer was eroded as one and a half times faster than a novolak resin, and a little faster than an anthracene incorporated polymer. The result was discussed from the concepts of Ohnishi parameter and the ring parameter for dry etch durability of resist materials. BARC polymer should be thermoset by hard bake to eliminate intermixing with resist compositions. The BARC polymer bearing hydroxy group which is useful for a crosslinking reaction was thermoset in the presence of melamine-formaldehyde crosslinker and an acid catalyst after baking over 200 degrees C.

  14. Anti-reflection coatings for silicon solar cells from hydrogenated diamond like carbon

    Science.gov (United States)

    Das, Debajyoti; Banerjee, Amit

    2015-08-01

    Aiming towards a specific application as antireflection coatings (ARC) in Si solar cells, the growth of hydrogenated diamond like carbon (HDLC) films, by RF magnetron sputtering, has been optimized through comprehensive optical and structural studies. Various physical properties of the films e.g., (ID/IG) ratio in the Raman spectra, percentage of sp3 hybridization in XPS spectra, H-content in the network, etc., have been correlated with different ARC application properties e.g., transmittance, reflectance, optical band gap, refractive index, surface roughness, etc. The ARC properties have been optimized on unheated substrates, through systematic variations of RF power, gas flow rate, gas pressure and finally controlled introduction of hydrogen to the DLC network at its most favorable plasma parameters. The optimum HDLC films possess (T700)max ∼ 95.8%, (R700)min ∼ 3.87%, (n700)min ∼ 1.62 along with simultaneous (Eg)max ∼ 2.53 eV and ∼75.6% of sp3 hybridization in the C-network, corresponding to a bonded H-content of ∼23 at.%. Encouraging improvements in the ARC properties over the optimized DLC film were obtained with the controlled addition of hydrogen, and the optimum HDLC films appear quite promising for applications in Si solar cells. Systematic materials development has been performed through comprehensive understanding of the parameter space and its optimization, as elaborately discussed.

  15. Low-temperature grown indium oxide nanowire-based antireflection coatings for multi-crystalline silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yu-Cian; Chen, Chih-Yao; Chen, I Chen [Institute of Materials Science and Engineering, National Central University, Taoyuan (China); Kuo, Cheng-Wen; Kuan, Ta-Ming; Yu, Cheng-Yeh [TSEC Corporation, Hsinchu (China)

    2016-08-15

    Light harvesting by indium oxide nanowires (InO NWs) as an antireflection layer on multi-crystalline silicon (mc-Si) solar cells has been investigated. The low-temperature growth of InO NWs was performed in electron cyclotron resonance (ECR) plasma with an O{sub 2}-Ar system using indium nanocrystals as seed particles via the self-catalyzed growth mechanism. The size-dependence of antireflection properties of InO NWs was studied. A considerable enhancement in short-circuit current (from 35.39 to 38.33 mA cm{sup -2}) without deterioration of other performance parameters is observed for mc-Si solar cells coated with InO NWs. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Antireflective bilayer coatings based on Al2O3 film for UV region

    Directory of Open Access Journals (Sweden)

    Marszałek Konstanty

    2015-03-01

    Full Text Available Bilayer antireflective coatings consisting of aluminium oxide Al2O3/MgF2 and Al2O3/SiO2 are presented in this paper. Oxide films were deposited by means of e-gun evaporation in vacuum of 5 × 10-3 Pa in the presence of oxygen, and magnesium fluoride was prepared by thermal evaporation on heated optical lenses made from quartz glass (Corning HPFS. Substrate temperature was maintained at 250 _C during the deposition. Thickness and deposition rate were controlled with a thickness measuring system Inficon XTC/2. The experimental results of the optical measurements carried out during and after the deposition process have been presented. Physical thickness measurements were made during the deposition process and resulted in 44 nm/52 nm for Al2O3/MgF2 and 44 nm/50 nm for Al2O3/SiO2 system. Optimization was carried out for ultraviolet region with minimum of reflectance at 300 nm. The influence of post deposition annealing on the crystal structure was determined by X-ray measurements. In the range from ultraviolet to the beginning of visible region, the reflectance of both systems decreased and reached minimum at 290 nm. The value of reflectance at this point, for the coating Al2O3/MgF2 was equal to R290nm = 0.6 % and for Al2O3/SiO2R290nm = 1.1 %. Despite the difference between these values both are sufficient for applications in the UV optical systems for medicine and UV laser technology.

  17. Design and fabrication of anti-reflection coating on Gallium Phosphide, Zinc Selenide and Zinc Sulfide substrates for visible and infrared application

    Directory of Open Access Journals (Sweden)

    Mokrý P.

    2013-05-01

    Full Text Available Results of design and fabrication of a dual-band anti-reflection coating on a gallium phosphide (GaP, zinc selenide (ZnSe and zinc sulfide (ZnS substrates are presented. A multilayer stack structure of antireflection coatings made of zinc sulfide and yttrium fluoride (YF3 was theoretically designed for optical bands between 0.8 and 0.9 μm and between 9.5 and 10.5 μm. This stack was designed as efficient for these materials (GaP, ZnS, ZnSe together. Multilayer stack structure was deposited using thermal evaporation method. Theoretically predicted transmittance spectra were compared with transmitted spectra measured on coated substrates. Efficiency of anti-reflection coating is estimated and discrepancies are analyzed and discussed.

  18. Design of multi-layer anti-reflection coating for terrestrial solar panel ...

    Indian Academy of Sciences (India)

    2National Centre for Photovoltaic Research & Education, Department of Electrical Engineering,. Indian Institute of Technology, Bombay 400 076, India. MS received 14 .... improve the anti-reflective property, a low refractive index material like ...

  19. Single layer broadband anti-reflective coatings for plastic substrates produced by full wafer and roll-to-roll step-and-flash nano-imprint lithography

    NARCIS (Netherlands)

    Burghoorn, M.M.A.; Roosen-Melsen, D.A.; Riet, J.F.J. de; Sabik, S.; Vroon, Z.A.E.P.; Yakimets, I.; Buskens, P.J.P.

    2013-01-01

    Anti-reflective coatings (ARCs) are used to lower the reflection of light on the surface of a substrate. Here, we demonstrate that the two main drawbacks of moth eye-structured ARCs-i.e., the lack of suitable coating materials and a process for large area, high volume applications-can be largely

  20. Reflective and antireflective coatings for the optical chain of the ASTRI SST-2M prototype

    Science.gov (United States)

    Bonnoli, Giacomo; Canestrari, Rodolfo; Catalano, Osvaldo; Pareschi, Giovanni; Perri, Luca; Stringhetti, Luca

    2013-09-01

    ASTRI is a Flagship Project of the Italian Ministry of Education, University and Research, led by the Italian National Institute of Astrophysics, INAF. One of the main aims of the ASTRI Project is the design, construction and on-field verification of a dual mirror (2M) end-to-end prototype for the Small Size Telescope (SST) envisaged to become part of the Cherenkov Telescope Array. The ASTRI SST-2M prototype is designed according to the Schwarzschild-Couder optical scheme, and adopts a camera based on Silicon Photo Multipliers (SiPM); it will be assembled at the INAF astronomical site of Serra La Nave on mount Etna (Catania, Italy) in the second half of 2014, and will start scientific validation phase soon after. With its 4m wide primary dish, the telescope will be sensitive to multi-TeV Very High Energy (VHE) gamma rays up to 100 TeV and above, with a point spread function of ~2 arcminutes and a wide (semiaperture 4.8°) corrected field of view. The peculiarities of the optical design and of the SiPM bandpass pushed towards specifically optimized choices in terms of reflective coatings for both the primary and the secondary mirror. Fully dielectric multi-layer coatings have been developed and tested as an option for the primary mirror, aiming to filter out the large Night Sky Background contamination at wavelengths λ>~700 nm. On the other hand, for the large monolithic secondary mirror a simpler design with quartz-overcoated aluminium has been optimized for incidences far from normality. The conformation of the ASTRI camera in turn pushed towards the design of a reimaging system based on thin pyramidal light guides, that could be optionally integrated in the focal surface, aiming to increase the fill factor. An anti-reflective coating optimized for a wide range of incident angles faraway from normality was specifically developed to enhance the UV-optical transparency of these elements. The issues, strategy, simulations and experimental results are thoroughly

  1. Argon plasma treatment of silicon nitride (SiN) for improved antireflection coating on c-Si solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Hemanta; Mitra, Suchismita; Saha, Hiranmay; Datta, Swapan Kumar; Banerjee, Chandan, E-mail: chandanbanerjee74@gmail.com

    2017-01-15

    Highlights: • Antireflection properties of argon plasma treated silicon nitride layer and its effect on crystalline silicon solar cell. • The reduction in reflection due to the formation of a silicon oxynitride/silicon nitride double layer. • EQE reveals a relative increase of 2.72% in J{sub sc} and 4.46% in conversion efficiency. - Abstract: Antireflection properties of argon plasma treated silicon nitride layer and its effect on crystalline silicon solar cell is presented here. Hydrogenated silicon nitride (a-SiN:H) layer has been deposited on a silicon substrate by Plasma Enhanced Chemical Vapour Deposition (PECVD) using a mixture of silane (SiH{sub 4}), ammonia (NH{sub 3}) and hydrogen (H{sub 2}) gases followed by a argon plasma treatment. Optical analysis reveals a significant reduction in reflectance after argon plasma treatment of silicon nitride layer. While FESEM shows nanostructures on the surface of the silicon nitride film, FTIR reveals a change in Si−N, Si−O and N−H bonds. On the other hand, ellipsometry shows the variation of refractive index and formation of double layer. Finally, a c-Si solar cell has been fabricated with the said anti-reflection coating. External quantum efficiency reveals a relative increase of 2.72% in the short circuit current density and 4.46% in conversion efficiency over a baseline efficiency of 16.58%.

  2. Substrate-Versatile Approach to Robust Antireflective and Superhydrophobic Coatings with Excellent Self-Cleaning Property in Varied Environments.

    Science.gov (United States)

    Ren, Tingting; He, Junhui

    2017-10-04

    Robust antireflective and superhydrophobic coatings are highly desired in wide applications, such as optical devices, solar cell panels, architectural and automotive glasses, lab-on chip systems, and windows for electronic devices. Meanwhile, simple, low-cost, and substrate-versatile fabrication is also essential toward real applications of such coatings. Herein, we developed a substrate-versatile strategy to fabricate robust antireflective and superhydrophobic coatings with excellent self-cleaning property in varied environments, including air and oil and after oil contamination. A mixed ethanol suspension, which consists of 1H,1H,2H,2H-perfluorooctyltriethoxysilane modified dual-sized silica nanoparticles and acid-catalyzed silica precursor, was first synthesized. The acid-catalyzed silica precursor could help to form a highly cross-linked silica network by connecting the silica nanoparticles, thus significantly enhancing the robustness of coatings. The as-prepared coatings were able to withstand a water drop impact test, sand abrasion test, tape adhesion test, and knife and pencil scratching tests. More importantly, it was also found that the wettability and self-cleaning property of coatings after oil contamination were surprisingly different from those in air and oil. These observations are explainable by the alteration of interface; i.e., the alteration of interface has significant effects on the functional properties of coatings. Additionally, the mixed suspension could be sprayed onto various hard and soft substrates including glass, polyethylene terephthalate (PET), polycarbonate (PC), and poly(methyl methacrylate) (PMMA), opening up a feasible route toward varied practical applications in solar cell panels, optical devices, architectural and automotive glasses, droplet manipulators, and fluid control.

  3. Application of CBD-Zinc Sulfide Film as an Antireflection Coating on Very Large Area Multicrystalline Silicon Solar Cell

    OpenAIRE

    U. Gangopadhyay; K. Kim; S. K. Dhungel; H. Saha; J. Yi

    2007-01-01

    The low-cost chemical bath deposition (CBD) technique is used to prepare CBD-ZnS films as antireflective (AR) coating for multicrystalline silicon solar cells. The uniformity of CBD-ZnS film on large area of textured multicrystalline silicon surface is the major challenge of CBD technique. In the present work, attempts have been made for the first time to improve the rate of deposition and uniformity of deposited film by controlling film stoichiometry and refractive index and also to minimize...

  4. SiO2 Antireflection Coatings Fabricated by Electron-Beam Evaporation for Black Monocrystalline Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Minghua Li

    2014-01-01

    Full Text Available In this work we prepared double-layer antireflection coatings (DARC by using the SiO2/SiNx:H heterostructure design. SiO2 thin films were deposited by electron-beam evaporation on the conventional solar cell with SiNx:H single-layer antireflection coatings (SARC, while to avoid the coverage of SiO2 on the front side busbars, a steel mask was utilized as the shelter. The thickness of the SiNx:H as bottom layer was fixed at 80 nm, and the varied thicknesses of the SiO2 as top layer were 105 nm and 122 nm. The results show that the SiO2/SiNx:H DARC have a much lower reflectance and higher external quantum efficiency (EQE in short wavelengths compared with the SiNx:H SARC. A higher energy conversion efficiency of 17.80% was obtained for solar cells with SiO2 (105 nm/SiNx:H (80 nm DARC, an absolute conversion efficiency increase of 0.32% compared with the conventional single SiNx:H-coated cells.

  5. Nanostructured antistatic and antireflective thin films made of indium tin oxide and silica over-coat layer

    Science.gov (United States)

    Cho, Young-Sang; Hong, Jeong-Jin; Yang, Seung-Man; Choi, Chul-Jin

    2010-08-01

    Stable dispersion of colloidal indium tin oxide nanoparticles was prepared by using indium tin oxide nanopowder, organic solvent, and suitable dispersants through attrition process. Various comminution parameters during the attrition step were studied to optimize the process for the stable dispersion of indium tin oxide sol. The transparent and conductive films were fabricated on glass substrate using the indium tin oxide sol by spin coating process. To obtain antireflective function, partially hydrolyzed alkyl silicate was deposited as over-coat layer on the pre-fabricated indium tin oxide film by spin coating technique. This double-layered structure of the nanostructured film was characterized by measuring the surface resistance and reflectance spectrum in the visible wavelength region. The final film structure was enough to satisfy the TCO regulations for EMI shielding purposes.

  6. Anti-reflective coating for visible light using a silver nanodisc metasurface with a refractive index of less than 1.0

    Science.gov (United States)

    Yasuda, Hideki; Matsuno, Ryo; Koito, Naoki; Hosoda, Hidemasa; Tani, Takeharu; Naya, Masayuki

    2017-12-01

    Suppression of visible-light reflection from material surfaces is an important technology for many applications such as flat-panel displays, camera lenses, and solar panels. In this study, we developed an anti-reflective coating design based on a silver nanodisc metasurface. The effective refractive index of a 10-nm-thick monolayer of silver nanodiscs was less than 1.0, which enabled strong suppression of reflection from the underlying substrate. The nanodisc structure was easy to fabricate using a conventional roll-to-roll wet-coating method. The anti-reflective structure was fabricated over a large area.

  7. A comparative study on omnidirectional anti-reflection SiO2 nanostructure films coating by glancing angle deposition

    Science.gov (United States)

    Prachachet, R.; Samransuksamer, B.; Horprathum, M.; Eiamchai, P.; Limwichean, S.; Chananonnawathorn, C.; Lertvanithphol, T.; Muthitamongkol, P.; Boonruang, S.; Buranasiri, P.

    2018-02-01

    Fabricated omnidirectional anti-reflection nanostructure films as a one of the promising alternative solar cell applications have attracted enormous scientific and industrial research benefits to their broadband, effective over a wide range of incident angles, lithography-free and high-throughput process. Recently, the nanostructure SiO2 film was the most inclusive study on anti-reflection with omnidirectional and broadband characteristics. In this work, the three-dimensional silicon dioxide (SiO2) nanostructured thin film with different morphologies including vertical align, slant, spiral and thin films were fabricated by electron beam evaporation with glancing angle deposition (GLAD) on the glass slide and silicon wafer substrate. The morphological of the prepared samples were characterized by field-emission scanning electron microscope (FE-SEM) and high-resolution transmission electron microscope (HRTEM). The transmission, omnidirectional and birefringence property of the nanostructure SiO2 films were investigated by UV-Vis-NIR spectrophotometer and variable angle spectroscopic ellipsometer (VASE). The spectrophotometer measurement was performed at normal incident angle and a full spectral range of 200 - 2000 nm. The angle dependent transmission measurements were investigated by rotating the specimen, with incidence angle defined relative to the surface normal of the prepared samples. This study demonstrates that the obtained SiO2 nanostructure film coated on glass slide substrate exhibits a higher transmission was 93% at normal incident angle. In addition, transmission measurement in visible wavelength and wide incident angles -80 to 80 were increased in comparison with the SiO2 thin film and glass slide substrate due to the transition in the refractive index profile from air to the nanostructure layer that improve the antireflection characteristics. The results clearly showed the enhanced omnidirectional and broadband characteristic of the three dimensional Si

  8. Dual functional porous anti-reflective coatings with a photocatalytic effect based on a single layer system

    Science.gov (United States)

    Jilavi, M. H.; Mousavi, S. H.; Müller, T. S.; de Oliveira, P. W.

    2018-05-01

    Anti-reflection and photocatalytic properties are desirable for improving the optical properties of electronic devices. We describe a method of fabrication a single-layer, anti-reflective (AR) thin film with an additional photocatalytic property. The layer is deposited on glass substrates by means of a low-cost dip-coating method using a SiO2-TiO2 solution. A comparative study was undertaken to investigate the effects of TiO2 concentrations on the photocatalytic properties of the film and to determine the optimal balance between transmittance and photocatalysis. The average transmittance increases from T = 90.51% to T = 95.46 ± 0.07% for the wavelengths between 380 and 1200 nm. The structural characterization indicated the formation of thin, porous SiO2-TiO2 films with a roughness of less than 7.5 nm. The quality of the samples was evaluated by a complete test program of the mechanical, chemical and accelerated weathering stability. This results open up new possibilities for cost-effective AR coatings for the glass and solar cell industries.

  9. THE INFLUENCE OF PLASMONIC AND DIELECTRIC INCLUSIONS ON ANTIREFLECTIVE PROPERTIES OF HOMOGENEOUS COATINGS FOR SILICON PHOTOVOLTAIC STRUCTURES

    Directory of Open Access Journals (Sweden)

    K. V. Baryshnikova

    2015-09-01

    Full Text Available Subject of Study. Theoretical analysis of the efficiency for the antireflective coatings based on plasmonic silver (Ag and dielectric silicon (Si nanoparticles is presented. We observe the increase of light absorption in the active layer, which is related to the optical resonant properties of considered nanoparticles. Characteristic property of the studied composite layer is its ability to combine the functions of electric contacts and anti-reflective coating. Method. Numerical calculations were performed in CST Microwave Studio with FDFD method (Finite Difference in Frequency Domain. The optical parameters of materials were extracted from the experimentally measured data available in literature. Geometrical parameters of composite layer – size and location of particles – were varied. Comparison of light absorption efficiency for different coatings on top of the active layer is presented: the homogeneous Indium Tin Oxide (ITO layer, ITO layer with the spherical nanoparticle inclusions on the ITO surface, ITO layer with spherical nanoparticle bulk inclusions. Periodical lattices of particles with sizes of range between 15 and 80 nm were considered. Nanoparticles of this size have dominant dipole response. Main Results. Numerical calculations have shown that nanoparticle inclusions cause significant deformation of the absorption spectra with appearing of resonant pecularities in the wavelength range equal to 300-800 nm. It originates from the nanoparticle resonant features, which are similar to the resonant features of isolated nanoparticles. Absorption in the active layer decreases sharply at the resonant wavelength. Resonant response of nanoparticles placed on the ITO surface differs significally from the isolated ones: the resonant frequency and Q-factor decrease. It was shown that absorption in the active layer decreases by 25 % when the size of Ag and Si particles increases. Ag nanoparticles, placed in ITO layer on top of the active layer

  10. Enhancement of the CIGS solar cell's efficiency by anti-reflection coating with teflon AF

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Hong-Sub; Kim, Chan; Rhee, Il-Su [Kyungpook National University, Daegu (Korea, Republic of); Jo, Hyun-Jun; Kim, Dae-Hwan [Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of); Hong, Sung-Wook [Daegu University, Gyeongsan (Korea, Republic of)

    2014-11-15

    An anti-reflection (AR) layer of Teflon AF was deposited on the front surface of a Cu(In,Ga)Se{sub 2} (CIGS) solar cell with a structure of grid/TCO/ZnO/CdS/Cu(In,Ga)Se{sub 2}/Mo/glass by using the spin coating method. This AR layer reduced the front-surface reflection, which resulted in high efficiency for the CIGS solar cell. The thickness of the Teflon AF layer was varied to determine the thickness that gave the highest transmittance of incident light into the active absorber of the CIGS solar cell. The optimum thickness of the Teflon AF layer was found to be 105 nm. CIGS solar cells with a Teflon AF layer of 105 nm were constructed, and their efficiencies were compared with those of solar cells without a Teflon AF layer. The average increase in the relative efficiency of the solar cells was 2.63% due to the inclusion of an anti-reflection layer of Teflon AF.

  11. Influence of double- and triple-layer antireflection coatings on the formation of photocurrents in multijunction III–V solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Musalinov, S. B.; Anzulevich, A. P.; Bychkov, I. V. [Chelyabinsk State University (Russian Federation); Gudovskikh, A. S. [Russian Academy of Sciences, St. Petersburg Academic University (Russian Federation); Shvarts, M. Z., E-mail: shvarts@scell.ioffe.ru [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation)

    2017-01-15

    The results of simulation by the transfer-matrix method of TiO{sub 2}/SiO{sub 2} double-layer and TiO{sub 2}/Si{sub 3}N{sub 4}/SiO{sub 2} triple-layer antireflection coatings for multijunction InGaP/GaAs/Ge heterostructure solar cells are presented. The TiO{sub 2}/SiO{sub 2} double-layer antireflection coating is experimentally developed and optimized. The experimental spectral dependences of the external quantum yield of the InGaP/GaAs/Ge heterostructure solar cell and optical characteristics of antireflection coatings, obtained in the simulation, are used to determine the photogenerated current densities of each subcell in the InGaP/GaAs/Ge solar cell under AM1.5D irradiation conditions (1000 W/m{sup 2}) and for the case of zero reflection loss. It is shown in the simulation that the optimized TiO{sub 2}/Si{sub 3}N{sub 4}/SiO{sub 2} triple-layer antireflection coating provides a 2.3 mA/cm{sup 2} gain in the photocurrent density for the Ge subcell under AM1.5D conditions in comparison with the TiO{sub 2}/SiO{sub 2} double-layer antireflection coating under consideration. This thereby provides an increase in the fill factor of the current–voltage curve and in the output electric power of the multijunction solar cell.

  12. Ta2O5/ Al2O3/ SiO2 - antireflective coating for non-planar optical surfaces by atomic layer deposition

    Science.gov (United States)

    Pfeiffer, K.; Schulz, U.; Tünnermann, A.; Szeghalmi, A.

    2017-02-01

    Antireflective coatings are essential to improve transmittance of optical elements. Most research and development of AR coatings has been reported on a wide variety of plane optical surfaces; however, antireflection is also necessary on nonplanar optical surfaces. Physical vapor deposition (PVD), a common method for optical coatings, often results in thickness gradients on strongly curved surfaces, leading to a failure of the desired optical function. In this work, optical thin films of tantalum pentoxide, aluminum oxide and silicon dioxide were prepared by atomic layer deposition (ALD), which is based on self-limiting surface reactions. The results demonstrate that ALD optical layers can be deposited on both vertical and horizontal substrate surfaces with uniform thicknesses and the same optical properties. A Ta2O5/Al2O3/ SiO2 multilayer AR coating (400-700 nm) was successfully applied to a curved aspheric glass lens with a diameter of 50 mm and a center thickness of 25 mm.

  13. Modelling of solar cells with down-conversion of high energy photons, anti-reflection coatings and light trapping

    International Nuclear Information System (INIS)

    Vos, Alexis de; Szymanska, Aleksandra; Badescu, Viorel

    2009-01-01

    In classical solar cells, each absorbed photon gives rise to one electron-hole pair, irrespective of the photon energy. By applying an appropriate photoluminescent layer in front of the solar cell semiconductor, one can convert one high energy photon into two low energy photons (so-called down-conversion). In the present study, we do not consider photoluminescent layers that merely shift down photon energies (without enhancing the number of photons). In principle, these two photons can then generate two electron-hole pairs in the solar cell, thus increasing the efficiency of the device. However, the two photons emitted by the converter, are not necessarily emitted in the direction of the semiconductor: they can also be emitted in the direction 'back to the sun'. As most semiconductors have a high refractive index, in case the luminescent material has a low refractive index, more than half of the photoluminescence emission is lost in the sun direction, resulting in a net loss of light current generated by the solar cell instead of an increase. On the other hand, a high refractive index of the conversion layer (e.g. equal to the solar cell refractive index) will lead to a bad optical coupling with the air and a good optical coupling with the semiconductor, and therefore, more than 50% of the emitted low energy photons will actually reach the solar cell. However, in the latter case, many solar photons do not reach the converter in the first place because of reflection at the air-converter interface. As a result, it turns out that, in the absence of any anti-reflection coating, a refractive index n 2 of the converting layer in the range between n 1 1/2 and n 1 is optimal, where n 1 is the refractive index of the solar cell material. If, however, an anti-reflection coating is applied between air and the converter, the best choice for n 2 is n 1 . Finally, if two anti-reflection coatings are applied (the former between air and the converter, the latter between the

  14. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger

    2014-01-01

    We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used in an inject......We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used...

  15. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger

    We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used in an inject......We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used...

  16. Improved opto-electronic properties of silicon heterojunction solar cells with SiO x /Tungsten-doped indium oxide double anti-reflective coatings

    Science.gov (United States)

    Yu, Jian; Zhou, Jie; Bian, Jiantao; Zhang, Liping; Liu, Yucheng; Shi, Jianhua; Meng, Fanying; Liu, Jinning; Liu, Zhengxin

    2017-08-01

    Amorphous SiO x was prepared by plasma enhanced chemical vapor deposition (PECVD) to form SiO x /tungsten-doped indium oxide (IWO) double anti-reflective coatings for silicon heterojunction (SHJ) solar cell. The sheet resistance of SiO x /IWO stacks decreases due to plasma treatment during deposition process, which means thinner IWO film would be deposited for better optical response. However, the comparisons of three anti-reflective coating (ARC) structures reveal that SiO x film limits carier transport and the path of IWO-SiO x -Ag structure is non-conductive. The decrease of sheet resistance is defined as pseudo conductivity. IWO film capping with SiO x allows observably reduced reflectance and better response in 300-400 and 600-1200 nm wavelength ranges. Compared with IWO single ARC, the average reflection is reduced by 1.65% with 70 nm SiO x /80 nm IWO double anti-reflective coatings (DARCs) in 500-1200 nm wavelength range, leading to growing external quantum efficiency response, short circuit current density (J sc), and efficiency. After well optimization of SiO x /IWO stacks, an impressive efficiency of 23.08% is obtained with high J sc and without compromising open circuit voltage (V oc) and fill factor. SiO x /IWO DARCs provide better anti-reflective properties over a broad range of wavelength, showing promising application for SHJ solar cells.

  17. Understanding deviations in lithographic patterns near interfaces: Characterization of bottom anti-reflective coatings (BARC) and the BARC resist interface

    Science.gov (United States)

    Lenhart, Joseph L.; Fischer, Daniel; Sambasivan, Sharadha; Lin, Eric K.; Wu, Wen-Li; Guerrero, Douglas J.; Wang, Yubao; Puligadda, Rama

    2007-02-01

    Interactions between a bottom anti-reflective coating (BARC) and a photoresist can critically impact lithographic patterns. For example, a lithographic pattern can shrink or spread near a BARC interface, a process called undercutting or footing respectively, due to incompatibility between the two materials. Experiments were conducted on two industrial BARC coatings in an effort to determine the impact of BARC surface chemistry on the footing and undercutting phenomena. The BARC coatings were characterized by near edge X-ray absorption fine structure (NEXAFS), contact angle measurements, and neutron and X-ray reflectivity. Contact angle measurement using a variety of fluids showed that the fluid contact angles were independent of the type of BARC coating or the BARC processing temperature. NEXAFS measurements showed that the surface chemistry of each BARC was also independent of the processing temperature. These results suggest that acid-base interactions at the BARC-resist interface are not the cause of the footing-undercutting phenomena encountered in lithographic patterns.

  18. Stability of anti-reflection coatings via the self-assembly encapsulation of silica nanoparticles by diazo-resins

    Science.gov (United States)

    Metzman, Jonathan S.; Ridley, Jason I.; Khalifa, Moataz B.; Heflin, James R.

    2015-12-01

    A modified silica nanoparticle (MSNP) solution was formed by the encapsulation of negatively charged silica nanoparticles by the UV-crosslinkable polycation oligomer diazo-resin (DAR). Appropriate DAR encapsulation concentrations were determined by use of zeta-potential and dynamic light scattering measurements. The MSNPs were used in conjunction with poly(styrene sulfonate) (PSS) to grow homogenous ionic self-assembled multilayer anti-reflection coatings. Stability was induced within the films by the exposure of UV-irradiation that allowed for crosslinking of the DAR and PSS. The films were characterized by UV/vis/IR spectroscopy and field emission scanning electron microscopy. The transmission and reflection levels were >98.5% and <0.05%, respectively. The refractive indices resided in the 1.25-1.26 range. The solvent stability was tested by sonication of the films in a ternary solvent (H2O/DMF/ZnCl2 3:5:2 w/w/w).

  19. Long term testing and evaluation of PV modules with and without Sunarc antireflective coating of the cover glass

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Han, Jiangong

    2015-01-01

    Two Photovoltaic (PV) modules have been manufactured by Swemodule. One with Sunarc antireflective coated glass and one without glass surface treatment. The modules have been tested at DTU during 16 months under realistic outdoor conditions. Exactly the same polycrystalline cells were used...... in the modules. No cleaning of the glass has been made except for removal of bird droppings and leaves on single cells that could give a very wrong comparison. The PV modules were mounted due south at 45 degree tilt angle. They were connected to the electric grid with small 250W module inverters from Involar...... that also realized the MPP tracking to give the maximum output of each module. The electric power output was measured both on the AC and DC side and with different measurement equipment to be sure about the accuracy in improvement. The results indicate a potential long term improvement in a system from 3...

  20. Antireflection coating design for series interconnected multi-junction solar cells

    International Nuclear Information System (INIS)

    Aiken, Daniel J.

    1999-01-01

    AR coating design for multi-junction solar cells can be more challenging than in the single junction case. Reasons for this are discussed. Analytical expressions used to optimize AR coatings for single junction solar cells are extended for use in monolithic, series interconnected multi-junction solar cell AR coating design. The result is an analytical expression which relates the solar cell performance (through J(sub SC)) directly to the AR coating design through the device reflectance. It is also illustrated how AR coating design can be used to provide an additional degree of freedom for current matching multi-junction devices

  1. Electrical and Optical Characterization of Sputtered Silicon Dioxide, Indium Tin Oxide, and Silicon Dioxide/Indium Tin Oxide Antireflection Coating on Single-Junction GaAs Solar Cells

    Directory of Open Access Journals (Sweden)

    Wen-Jeng Ho

    2017-06-01

    Full Text Available This study characterized the electrical and optical properties of single-junction GaAs solar cells coated with antireflective layers of silicon dioxide (SiO2, indium tin oxide (ITO, and a hybrid layer of SiO2/ITO applied using Radio frequency (RF sputtering. The conductivity and transparency of the ITO film were characterized prior to application on GaAs cells. Reverse saturation-current and ideality factor were used to evaluate the passivation performance of the various coatings on GaAs solar cells. Optical reflectance and external quantum efficiency response were used to evaluate the antireflective performance of the coatings. Photovoltaic current-voltage measurements were used to confirm the efficiency enhancement obtained by the presence of the anti-reflective coatings. The conversion efficiency of the GaAs cells with an ITO antireflective coating (23.52% exceeded that of cells with a SiO2 antireflective coating (21.92%. Due to lower series resistance and higher short-circuit current-density, the carrier collection of the GaAs cell with ITO coating exceeded that of the cell with a SiO2/ITO coating.

  2. Realization of Colored Multicrystalline Silicon Solar Cells with SiO2/SiNx:H Double Layer Antireflection Coatings

    Directory of Open Access Journals (Sweden)

    Minghua Li

    2013-01-01

    Full Text Available We presented a method to use SiO2/SiNx:H double layer antireflection coatings (DARC on acid textures to fabricate colored multicrystalline silicon (mc-Si solar cells. Firstly, we modeled the perceived colors and short-circuit current density (Jsc as a function of SiNx:H thickness for single layer SiNx:H, and as a function of SiO2 thickness for the case of SiO2/SiNx:H (DARC with fixed SiNx:H (refractive index n=2.1 at 633 nm, and thickness = 80 nm. The simulation results show that it is possible to achieve various colors by adjusting the thickness of SiO2 to avoid significant optical losses. Therefore, we carried out the experiments by using electron beam (e-beam evaporation to deposit a layer of SiO2 over the standard SiNx:H for 156×156 mm2 mc-Si solar cells which were fabricated by a conventional process. Semisphere reflectivity over 300 nm to 1100 nm and I-V measurements were performed for grey yellow, purple, deep blue, and green cells. The efficiency of colored SiO2/SiNx:H DARC cells is comparable to that of standard SiNx:H light blue cells, which shows the potential of colored cells in industrial applications.

  3. An Evaluation of Atmospheric-pressure Plasma for the Cost-Effective Deposition of Antireflection Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rob Sailer; Guruvenket Srinivasan; Kyle W. Johnson; Douglas L. Schulz

    2010-04-01

    Atmospheric-pressure plasma deposition (APPD) has previously been used to deposit various functional materials including polymeric surface modification layers, transparent conducting oxides, and photo catalytic materials. For many plasma polymerized coatings, reaction occurs via free radical mechanism where the high energy electrons from the plasma activate the olefinic carbon-carbon double bonds - a typical functional group in such precursors. The precursors for such systems are typically inexpensive and readily available and have been used in vacuum PECVD previously. The objectives are to investigate: (1) the effect of plasma power, gas composition and substrate temperature on the Si-based film properties using triethylsilane(TES) as the precursor; and (2) the chemical, mechanical, and optical properties of several experimental matrices based on Design of Experiment (DOE) principals. A simple APPD route has been utilized to deposit Si based films from an inexpensive precursor - Triethylsilane (TES). Preliminary results indicates formation of Si-C & Si-O and Si-O, Si-C & Si-N bonds with oxygen and nitrogen plasmas respectively. N{sub 2}-O{sub 2} plasma showed mixed trend; however oxygen remains a significant portion of all films, despite attempts to minimize exposure to atmosphere. SiN, SiC, and SiO ratios can be modified by the reaction conditions resulting in differing film properties. SE studies revealed that films with SiN bond possess refractive index higher than coatings with Si-O/Si-C bonds. Variable angle reflectance studies showed that SiOCN coatings offer AR properties; however thickness and refractive index optimization of these coatings remains necessary for application as potential AR coatings.

  4. Composite films prepared by plasma ion-assisted deposition (IAD) for design and fabrication of antireflection coatings in visible and near-infrared spectral regions

    Science.gov (United States)

    Tsai, Rung-Ywan; Ho, Fang C.

    1994-11-01

    Ion-assisted deposition (IAD) processes configured with a well-controlled plasma source at the center base of a vacuum chamber, which accommodates two independent e-gun sources, is used to deposition TiO2MgF2 and TiO2-SiO2 composite films of selected component ratios. Films prepared by this technology are found durable, uniform, and nonabsorbing in visible and near-IR regions. Single- and multilayer antireflection coatings with refractive index from 1.38 to 2.36 at (lambda) equals 550 nm are presented. Methods of enhancement in optical performance of these coatings are studied. The advantages of AR coatings formed by TiO2-MgF2 composite films over those similar systems consisting of TiO2-SiO2 composite films in both visible and near-IR regions are also presented.

  5. Functional photocatalytically active and scratch resistant antireflective coating based on TiO{sub 2} and SiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, M., E-mail: michal.mazur@pwr.edu.pl [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Wojcieszak, D.; Kaczmarek, D.; Domaradzki, J. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Song, S.; Gibson, D.; Placido, F. [Institute of Thin Films, Sensors & Imaging, University of the West of Scotland, Scottish Universities Physics Alliance, High Street, Paisley PA1 2BE (United Kingdom); Mazur, P. [University of Wroclaw, Institute of Experimental Physics, Max Born 9, 50-204 Wroclaw (Poland); Kalisz, M. [Motor Transport Institute, Centre for Material Testing and Mechatronics, Jagiellonska 80, 03-301 Warsaw (Poland); Poniedzialek, A. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland)

    2016-09-01

    Graphical abstract: - Highlights: • Designed multilayer was deposited by microwave assisted magnetron sputtering method. • AR coating in designed wavelength range had transmittance higher than 97%. • The AR multilayer was hydrophobic and photocatalytically active. • AR coating was scratch resistant. • Deposited multilayer had higher hardness than the glass substrate. - Abstract: Antireflection (AR) multilayer coating, based on combination of five TiO{sub 2} and SiO{sub 2} thin films, was deposited by microwave assisted reactive magnetron sputtering process on microscope glass substrates. In this work X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy and wettability measurements were used to characterize the structural and surface properties of the deposited coating. These studies revealed that prepared coating was amorphous with low surface roughness. Photocatalytic properties were determined based on phenol decomposition reaction. Measurements of optical properties showed that transmittance in the visible wavelength range was increased after the deposition of AR coating as-compared to bare glass substrate. The mechanical properties were determined on the basis of nano-indentation and scratch resistance tests. Performed research has shown that deposition of an additional thin 10 nm thick TiO{sub 2} thin film top layer, the prepared AR coating was photocatalytically active, hydrophobic, scratch resistant and had increased hardness as-compared to bare glass substrate. These results indicate that prepared AR multilayer could be used also as a self-cleaning and protective coating.

  6. Three-layer magnetoconvection

    International Nuclear Information System (INIS)

    Lin, M.-K.; Silvers, L.J.; Proctor, M.R.E.

    2008-01-01

    It is believed that some stars have two or more convection zones in close proximity near to the stellar photosphere. These zones are separated by convectively stable regions that are relatively narrow. Due to the close proximity of these regions it is important to construct mathematical models to understand the transport and mixing of passive and dynamic quantities. One key quantity of interest is a magnetic field, a dynamic vector quantity, that can drastically alter the convectively driven flows, and have an important role in coupling the different layers. In this Letter we present the first investigation into the effect of an imposed magnetic field in such a geometry. We focus our attention on the effect of field strength and show that, while there are some similarities with results for magnetic field evolution in a single layer, new and interesting phenomena are also present in a three layer system

  7. Effect of diffuse roof cover with anti-reflection coating for roses; Effect van diffuus kasdek met Anti Reflectie coating bij Roos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Victoria, N.; Kempkes, F.

    2012-10-15

    The rose Red Naomi was cultivated in two greenhouses at Wageningen UR Greenhouse Horticulture in Bleiswijk, Netherlands (August 2010 - September 2011). One greenhouse covered with normal float glass; the other with AR coated diffuse glass (70% haze). This Anti-Reflection coating on both glass sides compensated for the loss in light transmission caused by the diffusing structure in the glass. The diffuse AR glass lead to a 5.2% higher production (>6.1% fresh weight). Sunscreens were necessary in spring and summer to avoid high light levels on the flower buds, as they cause very high bud temperatures leading to quality problems (blue petal edges and burnt leaf tips). The diffuse greenhouse cover allowed a 100 W/m{sup 2} higher screening threshold than the reference glass. This caused a 2.7% higher daily light integral, able to explain part of the extra production obtained. Part of the extra production achieved can not be explained by the measured factors as no differences were found in the amount of light intercepted by the crop or in leaf photosynthesis under both cover types. The light under the diffuse AR cover was nevertheless much smoother, so the crop seemed to suffer less (lower bud temperatures and less burned leaf tips), and this should provide an explanation for the rest of the extra production. The cover properties did not influence disease development (powdery mildew). The obtained extra production makes the tempered, diffuse glass with Anti Reflection coating on both sides economically feasible [Dutch] Tussen augustus 2010 en september 2011 is bij Wageningen UR Glastuinbouw het effect van diffuus glas, met dubbelzijdige AR coating, op de productie en energiegebruik van roos 'Red Naomi' onderzocht. Onder het diffuse glas werden 5,2% meer bloemtakken geproduceerd, deze rozen waren ook iets langer en zwaarder (6,1% meer versgewicht). Dit verschil kan deels verklaard worden doordat er onder het diffuse glas pas bij hogere stralingsniveau

  8. High-etch-rate bottom-antireflective coating and gap-fill materials using dextrin derivatives in via first dual-Damascene lithography process

    Science.gov (United States)

    Takei, Satoshi; Sakaida, Yasushi; Shinjo, Tetsuya; Hashimoto, Keisuke; Nakajima, Yasuyuki

    2008-03-01

    The present paper describes a novel class of bottom antireflective coating (BARC) and gap fill materials using dextrin derivatives. The general trend of interconnect fabrication for such a high performance LSI is to apply cupper (Cu)/ low-dielectric-constant (low-k) interconnect to reduce RC delay. A via-first dual damascene process is one of the most promising processes to fabricate Cu/ low-k interconnect due to its wide miss-alignment margin. The sacrificial materials containing dextrin derivatives under resist for lithography were developed in via-first dual damascene process. The dextrin derivatives in this study was obtained by the esterification of the hydroxyl groups of dextrin resulting in improved solubility in the resist solvents such as propylene glycol monomethylether, propylene glycol monomethylether acetate, and ethyl lactate due to avoid the issue of defects that were caused by incompatability. The etch rate of our developed BARC and gap fill materials using dextrin derivatives was more than two times faster than one of the ArF resists evaluated in a CF4 gas condition using reactive ion etching. The improved etch performance was also verified by comparison with poly(hydroxystyrene), acrylate-type materials and latest low-k materials as a reference. In addition to superior etch performance, these materials showed good resist profiles and via filling performance without voids in via holes.

  9. Improvement in photovoltaic properties of silicon solar cells with a doped porous silicon layer with rare earth (Ce, La) as antireflection coatings

    International Nuclear Information System (INIS)

    Atyaoui, Malek; Dimassi, Wissem; Atyaoui, Atef; Elyagoubi, Jalel; Ouertani, Rachid; Ezzaouia, Hatem

    2013-01-01

    The performance improvement of solar cells due to the formation of a porous silicon layer treated with rare earth (Ce, La) in the n + emitter of silicon n + /p junctions has been investigated. The photovoltaic properties of the cells with and without treatment of the porous silicon layer are compared. From the reflection measurements, it was shown that the cells with treated PS layers have lower reflectivity value compared to cell with untreated PS layer. The main result is that the photovoltaic energy conversion efficiency of solar cells can be enhanced by using the treated porous silicon layers with the rare earth (Ce, La) as anti-reflection coatings. -- Highlights: • The reduction of optical loss in silicon (c-Si) solar cells attracts the attention of many researches to achieve high efficiencies. • To attain this aim, the treated PS layers with rare earth (La, Ce) are suggested to be used as an (ARC) of c-Si solar cell. • The result showed a decrease in the optical losses which can explain the improved photovoltaic properties

  10. Improvement in photovoltaic properties of silicon solar cells with a doped porous silicon layer with rare earth (Ce, La) as antireflection coatings

    Energy Technology Data Exchange (ETDEWEB)

    Atyaoui, Malek, E-mail: atyaoui.malek@yahoo.fr [Laboratoire de Photovoltaïque, Centre de recherches et des technologies de l' energie, technopole de Borj-Cédria, PB:95, Hammam Lif 2050 (Tunisia); Dimassi, Wissem [Laboratoire de Photovoltaïque, Centre de recherches et des technologies de l' energie, technopole de Borj-Cédria, PB:95,Hammam Lif 2050 (Tunisia); Atyaoui, Atef [Laboratoire de traitement des eaux usées, Centre de recherches et des technologies des eaux, technopole de Borj-Cédria, PB: 273, Soliman 8020 (Tunisia); Elyagoubi, Jalel; Ouertani, Rachid; Ezzaouia, Hatem [Laboratoire de Photovoltaïque, Centre de recherches et des technologies de l' energie, technopole de Borj-Cédria, PB:95,Hammam Lif 2050 (Tunisia)

    2013-09-15

    The performance improvement of solar cells due to the formation of a porous silicon layer treated with rare earth (Ce, La) in the n{sup +} emitter of silicon n{sup +}/p junctions has been investigated. The photovoltaic properties of the cells with and without treatment of the porous silicon layer are compared. From the reflection measurements, it was shown that the cells with treated PS layers have lower reflectivity value compared to cell with untreated PS layer. The main result is that the photovoltaic energy conversion efficiency of solar cells can be enhanced by using the treated porous silicon layers with the rare earth (Ce, La) as anti-reflection coatings. -- Highlights: • The reduction of optical loss in silicon (c-Si) solar cells attracts the attention of many researches to achieve high efficiencies. • To attain this aim, the treated PS layers with rare earth (La, Ce) are suggested to be used as an (ARC) of c-Si solar cell. • The result showed a decrease in the optical losses which can explain the improved photovoltaic properties.

  11. Optical properties of the Al2O3/SiO2 and Al2O3/HfO2/SiO2 antireflective coatings

    Science.gov (United States)

    Marszałek, Konstanty; Winkowski, Paweł; Jaglarz, Janusz

    2014-01-01

    Investigations of bilayer and trilayer Al2O3/SiO2 and Al2O3/HfO2/SiO2 antireflective coatings are presented in this paper. The oxide films were deposited on a heated quartz glass by e-gun evaporation in a vacuum of 5 × 10-3 [Pa] in the presence of oxygen. Depositions were performed at three different temperatures of the substrates: 100 °C, 200 °C and 300 °C. The coatings were deposited onto optical quartz glass (Corning HPFS). The thickness and deposition rate were controlled with Inficon XTC/2 thickness measuring system. Deposition rate was equal to 0.6 nm/s for Al2O3, 0.6 nm - 0.8 nm/s for HfO2 and 0.6 nm/s for SiO2. Simulations leading to optimization of the thin film thickness and the experimental results of optical measurements, which were carried out during and after the deposition process, have been presented. The optical thickness values, obtained from the measurements performed during the deposition process were as follows: 78 nm/78 nm for Al2O3/SiO2 and 78 nm/156 nm/78 nm for Al2O3/HfO2/SiO2. The results were then checked by ellipsometric technique. Reflectance of the films depended on the substrate temperature during the deposition process. Starting from 240 nm to the beginning of visible region, the average reflectance of the trilayer system was below 1 % and for the bilayer, minima of the reflectance were equal to 1.6 %, 1.15 % and 0.8 % for deposition temperatures of 100 °C, 200 °C and 300 °C, respectively.

  12. Improved antireflection based on biomimetic nanostructures at material interface

    Science.gov (United States)

    Zhang, Lingyu; Song, Gang

    2018-02-01

    Reducing light reflections on the surface of materials has important applications in many fields, such as solar cells, photodetectors, and optical sensors, etc. An effective method of decreasing reflection is using the anti-reflective coating with a gradient refractive index. In this study, we designed a nanostructure composed of optimized cone arrays on the flat thin film surface. The tapered nanostructure forms an anti-reflection layer. The effective refractive index of the anti-reflection layer changes smoothly with the depth so that the surface can efficiently reduce the reflection in a wide visible light range. Moreover, the reflection can also be modulated by adjusting the height and the period of the nanocones. Furthermore, there is an optimal wavelength at which the highest anti-reflection efficiency is achieved. The results here provide a theoretical guidance for the practical design of broadband anti-reflection nanostructures at the device surface.

  13. Comparison of Anti-Reflective Coated and Uncoated Surfaces Figured by Pitch-Polishing and Magneto-Rheological Processes

    International Nuclear Information System (INIS)

    Chow, R.; Thomas, M.D.; Bickel, R.; Taylor, J.R.

    2002-01-01

    When completed, the National Ignition Facility (NIF) will provide laser energies in the Mega-joule range. Successful pulse amplification to these extremely high levels requires that all small optics, found earlier in the beamline, have stringent surface and laser fluence requirements. In addition, they must operate reliably for 30 years constituting hundreds of thousands of shots. As part of the first four beamlines, spherical and aspherical lenses were required for the beam relaying telescopes. The magneto-rheological technique allows for faster and more accurate finishing of aspheres. The spherical and aspherical lenses were final figured using both conventional-pitch polishing processes for high quality laser optics and the magneto-rheological finishing process. The purpose of this paper is to compare the surface properties between these two finishing processes. Some lenses were set aside from production for evaluation. The surface roughness in the mid-frequency range was measured and the scatter was studied. Laser damage testing at 1064 nm (3-ns pulse width) was performed on surfaces in both the uncoated and coated condition.

  14. Photo-Electrical Characterization of Silicon Micropillar Arrays with Radial p/n Junctions Containing Passivation and Anti-Reflection Coatings

    NARCIS (Netherlands)

    Vijselaar, Wouter; Elbersen, R.; Tiggelaar, Roald M.; Gardeniers, Han; Huskens, Jurriaan

    2017-01-01

    In order to assess the contributions of anti-reflective and passivation effects in microstructured silicon-based solar light harvesting devices, thin layers of aluminum oxide (Al2O3), silicon dioxide (SiO2), silicon-rich silicon nitride (SiNx), and indium tin oxide (ITO), with a thickness ranging

  15. Sub-50-nm self-assembled nanotextures for enhanced broadband antireflection in silicon solar cells.

    Science.gov (United States)

    Rahman, Atikur; Ashraf, Ahsan; Xin, Huolin; Tong, Xiao; Sutter, Peter; Eisaman, Matthew D; Black, Charles T

    2015-01-21

    Materials providing broadband light antireflection have applications as highly transparent window coatings, military camouflage, and coatings for efficiently coupling light into solar cells and out of light-emitting diodes. In this work, densely packed silicon nanotextures with feature sizes smaller than 50 nm enhance the broadband antireflection compared with that predicted by their geometry alone. A significant fraction of the nanotexture volume comprises a surface layer whose optical properties differ substantially from those of the bulk, providing the key to improved performance. The nanotexture reflectivity is quantitatively well-modelled after accounting for both its profile and changes in refractive index at the surface. We employ block copolymer self-assembly for precise and tunable nanotexture design in the range of ~10-70 nm across macroscopic solar cell areas. Implementing this efficient antireflection approach in crystalline silicon solar cells significantly betters the performance gain compared with an optimized, planar antireflection coating.

  16. Fabrication of silicon solar cell with >18% efficiency using spin-on-film processing for phosphorus diffusion and SiO{sub 2}/graded index TiO{sub 2} anti-reflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yi-Yu; Ho, Wen-Jeng, E-mail: wjho@ntut.edu.tw; Yeh, Chien-Wu

    2015-11-01

    Highlights: • Employed SOF technology for both phosphorus diffusion and multi-layer ARCs. • Optical properties of TiO{sub 2}, SiO{sub 2}, and SiO{sub 2}/TiO{sub 2}/TiO{sub 2} films are characterized. • Photovoltaic performances of the fabricated solar cells are measured and compared. • An impressive efficiency of 18.25% was obtained by using the SOF processes. - Abstract: This study employed spin-on film (SOF) technology for the fabrication of phosphorus diffusion and multi-layer anti-reflective coatings (ARCs) with a graded index on silicon (Si) wafers. Low cost and high efficiency solar cells are important issues for the operating cost of a photovoltaic system. SOF technology for the fabrication of solar cells can be for the achievement of this goal. This study succeeded in the application of SOF technology in the preparation of both phosphorus diffusion and SiO{sub 2}/graded index TiO{sub 2} ARCs for Si solar cells. Optical properties of TiO{sub 2}, SiO{sub 2}, and multi-layer SiO{sub 2}/TiO{sub 2} deposition by SOF are characterized. Electrical and optical characteristics of the fabricated solar cells are measured and compared. An impressive efficiency of 18.25% was obtained by using the SOF processes.

  17. Superhydrophobic and anti-reflective ZnO nanorod-coated FTO transparent conductive thin films prepared by a three-step method

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bao-jia, E-mail: li_bjia@126.com [School of Materials Science and Engineering, Jiangsu University, Zhenjiang, 212013 (China); Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang, 212013 (China); Huang, Li-jing; Ren, Nai-fei [Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang, 212013 (China); School of Mechanical Engineering, Jiangsu University, Zhenjiang, 212013 (China); Kong, Xia; Cai, Yun-long; Zhang, Jie-lu [Jiangsu Tailong Reduction Box Co. Ltd., Taixing, 225400 (China)

    2016-07-25

    A ZnO nanorod-coated FTO film was prepared by sputtering an AZO layer on FTO glass, thermal annealing of the AZO/FTO film, and hydrothermal growth of ZnO nanorods at 70 °C on the annealed AZO/FTO film using zinc foils as zinc source. Two other ZnO nanorod-coated FTO films were also prepared by hydrothermal growths of ZnO nanorods on the FTO glass and the unannealed AZO/FTO film respectively for comparison purpose. The results were observed in detail using X-ray diffraction, scanning electron microscopy, water contact/sliding angle measurement, spectrophotometry and four-point probe measurement. The ZnO nanorods on the annealed AZO/FTO film were found to exhibit denser distribution and better orientation than those on the FTO glass and the unannealed AZO/FTO film. As a result, the ZnO nanorod-coated annealed AZO/FTO film demonstrated superhydrophobicity, high transparency and low reflectance in the visible range. Also this film had the lowest sheet resistance of 4.0 Ω/sq, implying its good electrical conductivity. This investigation provides a valuable reference for developing multifunctional transparent conductive films. - Highlights: • ZnO nanorod-coated annealed AZO/FTO film was obtained by a three-step method. • FTO and unannealed AZO/FTO films were also used as substrates for comparison. • ZnO nanorods on the annealed AZO/FTO film were denser and more vertically-oriented. • The ZnO nanorod-coated annealed AZO/FTO film (Z/TA-FTO) had superhydrophobicity. • The Z/TA-FTO exhibited high transparency, low reflectance and good conductivity.

  18. Simulation and fabrication of SiO{sub 2}/graded-index TiO{sub 2} antireflection coating for triple-junction GaAs solar cells by using the hybrid deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jheng-Jie; Ho, Wen-Jeng, E-mail: wjho@ntut.edu.tw; Lee, Yi-Yu; Chang, Chia-Ming

    2014-11-03

    GaAs-based multi-junction solar cells (MJ-SCs) provide a wide solar-energy absorption-band (300–1800 nm), but designing and fabricating a broadband antireflection coating (ARC) are challenging. Because MJ-SCs are typically in a series that connects each subcell, the total output current is limited by the subcell that generates the smallest photocurrent. Thus, the ARC for MJ-SCs must be designed not only to obtain broadband absorption but also to minimize light reflection at the wavelength band of the current-limited cell. This study proposes a broadband SiO{sub 2}/graded-index TiO{sub 2} ARC for improving the current-limited subcell performance by using a hybrid deposition (e-beam evaporation and spin-on coating). A bottom TiO{sub 2} layer and a top SiO{sub 2} layer were deposited through e-beam evaporation, but the middle TiO{sub 2} layer was deposited using spin-on coating because the refractive index values of the TiO{sub 2} films could be tuned by applying the spin speed. Therefore, the graded-index TiO{sub 2} layers were easily obtained using a hybrid deposition method. In addition, a suitable reflectance spectrum of an ARC structure for a middle-cell current-limited triple-junction (3-J) GaAs solar cell was simulated using commercial optical software. The photovoltaic current–voltage and external quantum efficiency (EQE) were measured and compared. The resulting improvements of a short-circuit current of 32.4% and conversion efficiency of 31.8% were attributed to an enhanced EQE of 32.97% as well as a low broadband reflectance exhibited on the middle cell of the 3-J GaAs solar cell with a SiO{sub 2}/graded-index TiO{sub 2} ARC. - Highlights: • A broadband SiO{sub 2}/graded-index TiO{sub 2} ARC obtained by a hybrid deposition • A suitable triple-layer ARC was simulated by a commercial optical software. • Optical reflection, photovoltaic I–V, and EQE of 3-J GaAs solar cell were characterized. • An increased J{sub sc} of 32.4% and an increased

  19. Development of antireflection coatings with a sup 6 LiF/ sup 6 sup 2 Ni multilayer converter for ultracold neutron detectors

    CERN Document Server

    Maier-Komor, P; Bergmaier, A; Dollinger, G; Paul, S; Schott, W

    2002-01-01

    High efficiency detectors for ultracold neutrons (UCN) are needed at the new high flux neutron source, Forschungsreaktor Muenchen II. In the development described, silicon PIN diodes were chosen to detect the alpha-particles or the tritons created in the reaction sup 6 Li(n,alpha)t. The high reflectance of UCN on sup 6 Li with its positive optical potential must be compensated by a material with negative optical potential. The isotope sup 6 sup 2 Ni was chosen for this. To avoid problems due to chemical reactions of Li with humidity, the compound sup 6 LiF was chosen. One hundred and fifty double layers of sup 6 LiF/ sup 6 sup 2 Ni had to be deposited by physical vapor deposition on silicon PIN diodes which had already been coated with 88 nm approx 77 mu g/cm sup 2 of sup 5 sup 8 Ni for reflection of the UCN. The theoretical optimal thickness of the sup 6 sup 2 Ni layers is 3 nm, and that of sup 6 LiF is 6 nm. Since expensive isotopes were involved, a small source-to-substrate distance had to be used, but wit...

  20. Self-Cleaning Antireflective Optical Coatings

    KAUST Repository

    Guldin, Stefan; Kohn, Peter; Stefik, Morgan; Song, Juho; Divitini, Giorgio; Ecarla, Fanny; Ducati, Caterina; Wiesner, Ulrich; Steiner, Ullrich

    2013-01-01

    -copolymer in combination with silica-based sol-gel chemistry and preformed TiO2 nanocrystals. The spontaneous dense packing of copolymer micelles followed by a condensation reaction results in an inverse opal-type silica morphology that is loaded with TiO2 photocatalytic

  1. Antireflection coatings on plastics deposited by plasma ...

    Indian Academy of Sciences (India)

    In the ophthalmic industry, plastic lenses are rapidly displacing glass lenses ... Moreover, the plasma polymerization process allows deposition of optical films at room temperature, essential for plastics. ... Bulletin of Materials Science | News.

  2. The role of random nanostructures for the omnidirectional anti-reflection properties of the glasswing butterfly

    Science.gov (United States)

    Siddique, Radwanul Hasan; Gomard, Guillaume; Hölscher, Hendrik

    2015-04-01

    The glasswing butterfly (Greta oto) has, as its name suggests, transparent wings with remarkable low haze and reflectance over the whole visible spectral range even for large view angles of 80°. This omnidirectional anti-reflection behaviour is caused by small nanopillars covering the transparent regions of its wings. In difference to other anti-reflection coatings found in nature, these pillars are irregularly arranged and feature a random height and width distribution. Here we simulate the optical properties with the effective medium theory and transfer matrix method and show that the random height distribution of pillars significantly reduces the reflection not only for normal incidence but also for high view angles.

  3. Two-layer anti-reflection strategies for implant applications

    Science.gov (United States)

    Guerrero, Douglas J.; Smith, Tamara; Kato, Masakazu; Kimura, Shigeo; Enomoto, Tomoyuki

    2006-03-01

    A two-layer bottom anti-reflective coating (BARC) concept in which a layer that develops slowly is coated on top of a bottom layer that develops more rapidly was demonstrated. Development rate control was achieved by selection of crosslinker amount and BARC curing conditions. A single-layer BARC was compared with the two-layer BARC concept. The single-layer BARC does not clear out of 200-nm deep vias. When the slower developing single-layer BARC was coated on top of the faster developing layer, the vias were cleared. Lithographic evaluation of the two-layer BARC concept shows the same resolution advantages as the single-layer system. Planarization properties of a two-layer BARC system are better than for a single-layer system, when comparing the same total nominal thicknesses.

  4. Biomimetic Moth-eye Nanofabrication: Enhanced Antireflection with Superior Self-cleaning Characteristic.

    Science.gov (United States)

    Sun, Jingyao; Wang, Xiaobing; Wu, Jinghua; Jiang, Chong; Shen, Jingjing; Cooper, Merideth A; Zheng, Xiuting; Liu, Ying; Yang, Zhaogang; Wu, Daming

    2018-04-03

    Sub-wavelength antireflection moth-eye structures were fabricated with Nickel mold using Roll-to-Plate (R2P) ultraviolet nanoimprint lithography (UV-NIL) on transparent polycarbonate (PC) substrates. Samples with well replicated patterns established an average reflection of 1.21% in the visible light range, 380 to 760 nm, at normal incidence. An excellent antireflection property of a wide range of incidence angles was shown with the average reflection below 4% at 50°. Compared with the unpatterned ultraviolet-curable resin coating, the resulting sub-wavelength moth-eye structure also exhibited increased hydrophobicity in addition to antireflection. This R2P method is especially suitable for large-area product preparation and the biomimetic moth-eye structure with multiple performances can be applied to optical devices such as display screens, solar cells, or light emitting diodes.

  5. Welding and manufacture technology of three-layer bellows

    International Nuclear Information System (INIS)

    Dou Zhengping; Jiang Yunbo; Xie Zhiqiang; Pei Qiusheng; Wang Jindong; Zhang Zhiqiang

    2005-01-01

    Using argon tungsten arc welding the technology research and manufacture was carried out for three-layer bellows with the diameter of 350 mm or 230 mm. The theory rigidity and fatigue intensity of welded bellows were experimentally confirmed, the reasonable welding parameters was selected, and three-layer welded bellows with the diameter of 350 mm or 230 mm were manufactured. Quality of welded bellows accords with techniques standard. (authors)

  6. Effects of laser radiation on surfaces and coatings

    International Nuclear Information System (INIS)

    Lowdermilk, W.H.

    1985-01-01

    A summary is given of the principal aspects of laser-induced damage to polished optical surfaces and dielectric, thin-film, high-reflectivity and antireflective coatings. Methods for producing porous antireflective surfaces and coatings and their damage properties are also reviewed. Finally, new areas of basic research to solve current and future problems are addressed

  7. Study on sodium water glass-based anti-reflective film and its application in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Q.Z. [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Shi, J.F., E-mail: shijf@ms.giec.ac.cn [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China); Wang, L.L.; Li, Y.J.; Zhong, L.W. [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China); Xu, G., E-mail: xugang@ms.giec.ac.cn [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China)

    2016-07-01

    In this paper, anti-reflective (AR) films are prepared from sodium water glass with a simple dip-coating method. The effects of SiO{sub 2}/Na{sub 2}O molar ratio, concentration of water glass, and withdrawal speed on the anti-reflection performance of the AR films are systematically studied. The optimized AR film is further applied in dye-sensitized solar cells (DSCs). The optical properties and surface morphology of AR films are analyzed by ultraviolet-visible spectrophotometer, scanning electron microscope, and atomic force microscope. Transmittance of the glass coated with sodium water glass-based AR film is increased by 3.2% when the SiO{sub 2}/Na{sub 2}O molar ratio, concentration, and withdrawal speed equal to 3.8, 5 wt%, and 80 mm/min, respectively. Under this condition, the thickness of the AR film is 127 nm and the AR film has obvious porous structure. In addition, the power conversion efficiency of DSC coated by AR film is increased from 7.92% to 8.24%, compared with the DSC without AR film. - Highlights: • Anti-reflective films are prepared from sodium water glass. • Transmittance of anti-reflective film is increased by 3.2%. • Efficiency of dye-sensitized cell is improved by anti-reflective film.

  8. Study on sodium water glass-based anti-reflective film and its application in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Huang, Q.Z.; Shi, J.F.; Wang, L.L.; Li, Y.J.; Zhong, L.W.; Xu, G.

    2016-01-01

    In this paper, anti-reflective (AR) films are prepared from sodium water glass with a simple dip-coating method. The effects of SiO_2/Na_2O molar ratio, concentration of water glass, and withdrawal speed on the anti-reflection performance of the AR films are systematically studied. The optimized AR film is further applied in dye-sensitized solar cells (DSCs). The optical properties and surface morphology of AR films are analyzed by ultraviolet-visible spectrophotometer, scanning electron microscope, and atomic force microscope. Transmittance of the glass coated with sodium water glass-based AR film is increased by 3.2% when the SiO_2/Na_2O molar ratio, concentration, and withdrawal speed equal to 3.8, 5 wt%, and 80 mm/min, respectively. Under this condition, the thickness of the AR film is 127 nm and the AR film has obvious porous structure. In addition, the power conversion efficiency of DSC coated by AR film is increased from 7.92% to 8.24%, compared with the DSC without AR film. - Highlights: • Anti-reflective films are prepared from sodium water glass. • Transmittance of anti-reflective film is increased by 3.2%. • Efficiency of dye-sensitized cell is improved by anti-reflective film.

  9. Antireflection/Passivation Step For Silicon Cell

    Science.gov (United States)

    Crotty, Gerald T.; Kachare, Akaram H.; Daud, Taher

    1988-01-01

    New process excludes usual silicon oxide passivation. Changes in principal electrical parameters during two kinds of processing suggest antireflection treatment almost as effective as oxide treatment in passivating cells. Does so without disadvantages of SiOx passivation.

  10. Coulomb oscillations in three-layer graphene nanostructures

    International Nuclear Information System (INIS)

    Guettinger, J; Stampfer, C; Molitor, F; Graf, D; Ihn, T; Ensslin, K

    2008-01-01

    We present transport measurements on a tunable three-layer graphene single electron transistor (SET). The device consists of an etched three-layer graphene flake with two narrow constrictions separating the island from source and drain contacts. Three lateral graphene gates are used to electrostatically tune the device. An individual three-layer graphene constriction has been investigated separately showing a transport gap near the charge neutrality point. The graphene tunneling barriers show a strongly nonmonotonic coupling as a function of gate voltage indicating the presence of localized states in the constrictions. We show Coulomb oscillations and Coulomb diamond measurements proving the functionality of the graphene SET. A charging energy of ∼0.6 meV is extracted.

  11. Design and analysis of three-layer-core optical fiber

    Science.gov (United States)

    Zheng, Siwen; Liu, Yazhuo; Chang, Guangjian

    2018-03-01

    A three-layer-core single-mode large-mode-area fiber is investigated. The three-layer structure in the core, which is composed of a core-index layer, a cladding-index layer, and a depression-index layer, could achieve a large effective area Aeff while maintaining an ultralow bending loss without deteriorating cutoff behaviors. The single-mode large mode area of 100 to 330 μm2 could be achieved in the fiber. The effective area Aeff can be further enlarged by adjusting the layer parameters. Furthermore, the bending property could be improved in this three-layer-core structure. The bending loss could decrease by 2 to 4 orders of magnitude compared with the conventional step-index fiber with the same Aeff. These characteristics of three-layer-core fiber suggest that it can be used in large-mode-area wide-bandwidth high-capacity transmission or high-power optical fiber laser and amplifier in optical communications, which could be used for the basic physical layer structure of big data storage, reading, calculation, and transmission applications.

  12. Electromagnetic Pulse of a Vertical Electric Dipole in the Presence of Three-Layered Region

    Directory of Open Access Journals (Sweden)

    D. Cheng

    2015-01-01

    Full Text Available Approximate formulas are obtained for the electromagnetic pulses due to a delta-function current in a vertical electric dipole on the planar surface of a perfect conductor coated by a dielectric layer. The new approximated formulas for the electromagnetic field in time domain are retreated analytically and some new results are obtained. Computations and discussions are carried out for the time-domain field components radiated by a vertical electric dipole in the presence of three-layered region. It is shown that the trapped-surface-wave terms should be included in the total transient field when both the vertical electric dipole and the observation point are on or near the planar surface of the dielectric-coated earth.

  13. Dynamic Response of Three-Layered Annular Plate with Imperfections

    Directory of Open Access Journals (Sweden)

    Pawlus Dorota

    2015-02-01

    Full Text Available This paper presents the imperfection sensitivity of annular plate with three-layered structure. The plate composed of thin elastic facings and a thicker elastic core is loaded in facing plane. The classical issue of a three-layered plate was solved for dynamic deflection problem using the approximation methods: orthogonalization and finite difference. The solution includes the axisymmetric and asymmetric plate modes of the dynamic stability loss. The evaluation of the rate of plate sensitivity to imperfection of plate preliminary geometry has been enriched by the analysis of plate models built of finite elements. The ABAQUS program has been used. The numerous calculation results in the form of deflection characteristics, buckling modes, values of critical parameters create the view of response of dynamic plate structure with different rate of imperfection and linear in time loading growth, too.

  14. Antireflective surface structures in glass by self-assembly of SiO2 nanoparticles and wet etching.

    Science.gov (United States)

    Maier, Thomas; Bach, David; Müllner, Paul; Hainberger, Rainer; Brückl, Hubert

    2013-08-26

    We describe the fabrication of an antireflective surface structure with sub-wavelength dimensions on a glass surface using scalable low-cost techniques involving sol-gel coating, thermal annealing, and wet chemical etching. The glass surface structure consists of sand dune like protrusions with 250 nm periodicity and a maximum peak-to-valley height of 120 nm. The antireflective structure increases the transmission of the glass up to 0.9% at 700 nm, and the transmission remains enhanced over a wide spectral range and for a wide range of incident angles. Our measurements reveal a strong polarization dependence of the transmission change.

  15. Antireflective glass nanoholes on optical lenses.

    Science.gov (United States)

    Lee, Youngseop; Bae, Sang-In; Eom, Jaehyeon; Suh, Ho-Cheol; Jeong, Ki-Hun

    2018-05-28

    Antireflective structures, inspired from moth eyes, are still reserved for practical use due to their large-area nanofabrication and mechanical stability. Here we report an antireflective optical lens with large-area glass nanoholes. The nanoholes increase light transmission due to the antireflective effect, depending on geometric parameters such as fill factor and height. The glass nanoholes of low effective refractive index are achieved by using solid-state dewetting of ultrathin silver film, reactive ion etching, and wet etching. An ultrathin silver film is transformed into nanoholes for an etch mask in reactive ion etching after thermal annealing at a low temperature. Unlike conventional nanopillars, nanoholes exhibit high light transmittance with enhancement of ~4% over the full visible range as well as high mechanical hardness. Also, an antireflective glass lens is achieved by directly employing nanoholes on the lens surface. Glass nanoholes of highly enhanced optical and mechanical performance can be directly utilized for commercial glass lenses in various imaging and lighting applications.

  16. Some exact results for the three-layer Zamolodchikov model

    International Nuclear Information System (INIS)

    Boos, H.E.; Mangazeev, V.V.

    2001-01-01

    In this paper we continue the study of the three-layer Zamolodchikov model started in our previous works (H.E. Boos, V.V. Mangazeev, J. Phys. A 32 (1999) 3041-3054 and H.E. Boos, V.V. Mangazeev, J. Phys. A 32 (1999) 5285-5298). We analyse numerically the solutions to the Bethe ansatz equations obtained in H.E. Boos, V.V. Mangazeev, J. Phys. A 32 (1999) 5285-5298. We consider two regimes I and II which differ by the signs of the spherical sides (a 1 ,a 2 ,a 3 )→(-a 1 ,-a 2 ,-a 3 ). We accept the two-line hypothesis for the regime I and the one-line hypothesis for the regime II. In the thermodynamic limit we derive integral equations for distribution densities and solve them exactly. We calculate the partition function for the three-layer Zamolodchikov model and check a compatibility of this result with the functional relations obtained in H.E. Boos, V.V. Mangazeev, J. Phys. A 32 (1999) 5285-5298. We also do some numeric checkings of our results

  17. The Influence of Three-Layer Knitted Fabrics’ Structure on Electrostatic and Comfort Properties

    Directory of Open Access Journals (Sweden)

    Sandra VARNAITĖ ŽURAVLIOVA

    2013-12-01

    Full Text Available In our times, when electricity and electrical devices are around us every day, it is very important to be protected from electrostatic discharge. The best protection from electric charge dissipation provides conductive textile materials. For the last few decades fine and flexible conductive yarns were developed, which ensure very good electrostatic properties. Unfortunately, due to their chemical nature, these yarns do not distinguish good comfort properties. The main purpose of development of such textiles is to determine the influence of conductive yarns and hollow fiber yarns arrangements in the middle layer of the three layer weft-knitted fabrics to electrostatic and comfort properties. So, in order to have flexible textile materials with good electrostatic and comfort properties, multifunctional three layer weft-knitted fabrics of combined pattern were designed and manufactured for this research work. Two groups of polyester based three layer knitted fabrics with different arrangement of conductive yarns (such as carbon core yarn and polyester silver coated yarn and polyester yarn of special design (Coolmax®, Thermolite® were investigated. The parameters of electrostatic characteristics, such as surface and vertical resistances as well as charge decay properties were measured. The results have showed that all tested fabrics have excellent shielding properties. The main influence on the electrostatic properties of tested fabrics has the arrangement of conductive carbon core yarns inserted in the knits. In order to evaluate the comfort of knitted fabrics the air permeability, hygroscopicity, time of absorption and drying degree of fabrics were evaluated. It was determined, that the values of comfort parameters depend on the quantity and distribution of Coolmax® and Thermolite® yarns in the fabrics.DOI: http://dx.doi.org/10.5755/j01.ms.19.4.2235

  18. Dispersion properties of three-layered orthotropic shells

    International Nuclear Information System (INIS)

    Markus, S.

    1995-01-01

    This paper studies the harmonic wave propagation in thick, cylindrical, three-layered shells of infinite length. Both the outer layers and the core are composites made of short strand fiberglass and polyester resin. The randomly oriented fibers were approximately in parallel planes to constitute a transversely isotropic fibre composite. The planes of isotropy in the outer layers are orthogonal to the plane of isotropy at the core. A closed form solution of the exact linear equations of elasticity in sought in terms of a Frobenius series. The influence of the core thickness on the dynamics of the wave motion is estimated from numerically computed dispersion curves. Asymmetric wave motion is given prime consideration and the different types of waves which can occur are identified over a wide range of wave numbers

  19. Strength of the Three Layer Beam with Two Binding Layers

    Directory of Open Access Journals (Sweden)

    Smyczyński M. J.

    2016-09-01

    Full Text Available The paper is devoted to the strength analysis of a simply supported three layer beam. The sandwich beam consists of: two metal facings, the metal foam core and two binding layers between the faces and the core. In consequence, the beam is a five layer beam. The main goal of the study is to elaborate a mathematical model of this beam, analytical description and a solution of the three-point bending problem. The beam is subjected to a transverse load. The nonlinear hypothesis of the deformation of the cross section of the beam is formulated. Based on the principle of the stationary potential energy the system of four equations of equilibrium is derived. Then deflections and stresses are determined. The influence of the binding layers is considered. The results of the solutions of the bending problem analysis are shown in the tables and figures. The analytical model is verified numerically using the finite element analysis, as well as experimentally.

  20. SANS study of three-layer micellar particles

    CERN Document Server

    Plestil, J; Kuklin, A I; Cubitt, R

    2002-01-01

    Three-layer nanoparticles were prepared by polymerization of methyl methacrylate (MMA) in aqueous micellar solutions of poly(methyl methacrylate)-block-poly(methacrylic acid) (PMMA-b-PMA) and polystyrene-block-poly(methacrylic acid) (PS-b-PMA). The resulting polymer forms a layer on the core surface of the original micelles. SANS curves were fitted using an ellipsoidal (PMMA/PMMA/PMA) or spherical (PS/PMMA/PMA) model for the particle core. The particle size (for the presented series of the PMMA/PMMA/PMA particles, the core semiaxes ranged from 87 to 187 A and the axis ratio was about 6) can be finely tuned by variation of monomer concentration. Time-resolved SANS experiments were carried out to describe the growth of the PS/PMMA/PMA particles during polymerization. (orig.)

  1. Antireflective Boundary Conditions for Deblurring Problems

    Directory of Open Access Journals (Sweden)

    Marco Donatelli

    2010-01-01

    Full Text Available This survey paper deals with the use of antireflective boundary conditions for deblurring problems where the issues that we consider are the precision of the reconstruction when the noise is not present, the linear algebra related to these boundary conditions, the iterative and noniterative regularization solvers when the noise is considered, both from the viewpoint of the computational cost and from the viewpoint of the quality of the reconstruction. In the latter case, we consider a reblurring approach that replaces the transposition operation with correlation. For many of the considered items, the anti-reflective algebra coming from the given boundary conditions is the optimal choice. Numerical experiments corroborating the previous statement and a conclusion section end the paper.

  2. Optimizing analysis of W-AlN cermet solar absorbing coatings

    International Nuclear Information System (INIS)

    Zhang Qichu

    2001-01-01

    The layer thickness and tungsten metal volume fraction of W-AlN cermet solar selective absorbing coatings on a W, Cu or Al infrared reflector with a surface aluminium oxynitride (AlON) or Al 2 O 3 ceramic anti-reflector layer were optimized using physical modelling calculations. Due to limited published data for the refractive index of AlN, and likely oxygen contamination during reactive sputtering of AlN ceramic materials, AlON was used as the ceramic component and the published value of its refractive index was employed. The dielectric function and then the complex refractive index of W-AlON cermet materials were calculated using the Ping Sheng approximation. The downhill simplex method in multi-dimensions was used in the numerical calculation to achieve maximum photo-thermal conversion efficiency at 350 0 C under a concentration factor of 30 for a solar collector tube. Optimization calculation results show that the initial graded (ten-step layers) cermet films all converge to something close to a three-layer film structure, which consists of a low metal volume fraction cermet layer on a high metal volume fraction cermet layer on a metallic infrared reflector with a surface ceramic anti-reflection layer. The optimized three-layer solar coatings have a high solar absorptance of 0.95 for AlON and 0.96 for the Al 2 O 3 anti-reflection layer, and a low hemispherical emittance of 0.073 at 350 deg. C. For the optimized three-layer films the solar radiation is efficiently absorbed internally and by phase interference. Thermal loss is very low for optimized three-layer films due to high reflectance values in the thermal infrared wavelength range and a very sharp edge between low solar reflectance and high thermal infrared reflectance. The high metal volume fraction cermet layer has a metal-like optical behaviour in the thermal infrared wavelength range and makes the largest contribution to the increase of emittance compared with that of the metal infrared reflector

  3. Optimizing analysis of W-AlN cermet solar absorbing coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qichu [School of Physics, University of Sydney, NSW (Australia)

    2001-11-07

    The layer thickness and tungsten metal volume fraction of W-AlN cermet solar selective absorbing coatings on a W, Cu or Al infrared reflector with a surface aluminium oxynitride (AlON) or Al{sub 2}O{sub 3} ceramic anti-reflector layer were optimized using physical modelling calculations. Due to limited published data for the refractive index of AlN, and likely oxygen contamination during reactive sputtering of AlN ceramic materials, AlON was used as the ceramic component and the published value of its refractive index was employed. The dielectric function and then the complex refractive index of W-AlON cermet materials were calculated using the Ping Sheng approximation. The downhill simplex method in multi-dimensions was used in the numerical calculation to achieve maximum photo-thermal conversion efficiency at 350{sup 0}C under a concentration factor of 30 for a solar collector tube. Optimization calculation results show that the initial graded (ten-step layers) cermet films all converge to something close to a three-layer film structure, which consists of a low metal volume fraction cermet layer on a high metal volume fraction cermet layer on a metallic infrared reflector with a surface ceramic anti-reflection layer. The optimized three-layer solar coatings have a high solar absorptance of 0.95 for AlON and 0.96 for the Al{sub 2}O{sub 3} anti-reflection layer, and a low hemispherical emittance of 0.073 at 350 deg. C. For the optimized three-layer films the solar radiation is efficiently absorbed internally and by phase interference. Thermal loss is very low for optimized three-layer films due to high reflectance values in the thermal infrared wavelength range and a very sharp edge between low solar reflectance and high thermal infrared reflectance. The high metal volume fraction cermet layer has a metal-like optical behaviour in the thermal infrared wavelength range and makes the largest contribution to the increase of emittance compared with that of the metal

  4. Optimizing analysis of W-AlN cermet solar absorbing coatings

    Energy Technology Data Exchange (ETDEWEB)

    Qi-Chu Zhang [University of Sydney, NSW (Australia). School of Physics

    2001-11-07

    The layer thickness and tungsten metal volume fraction of W-AlN cermet solar selective absorbing coatings on a W, Cu or Al infrared reflector with a surface aluminium oxynitride (AlON) or Al{sub 2}O{sub 3} ceramic anti-reflector layer were optimized using physical modelling calculations. Due to limited published data for the refractive index of AlN, and likely oxygen contamination during reactive sputtering of AlN ceramic materials, AlON was used as the ceramic component and the published value of its refractive index was employed. The dielectric function and then the complex refractive index of W-AlON cermet materials were calculated using the Ping Sheng approximation. The downhill simplex method in multi-dimensions was used in the numerical calculation to achieve maximum photo-thermal conversion efficiency at 350{sup o}C under a concentration factor of 30 for a solar collector tube. Optimization calculation results show that the initial graded (ten-step layers) cermet films all converge to something close to a three-layer film structure, which consists of a low metal volume fraction cermet layer on a high metal volume fraction cermet layer on a metallic infrared reflector with a surface ceramic anti-reflection layer. The optimized three-layer solar coatings have a high solar absorptance of 0.95 for AlON and 0.96 for the Al{sub 2}O{sub 3} anti-reflection layer, and a low hemispherical emittance of 0.073 at 350{sup o}C. For the optimized three-layer films the solar radiation is efficiently absorbed internally and by phase interference. Thermal loss is very low for optimized three-layer films due to high reflectance values in the thermal infrared wavelength range and a very sharp edge between low solar reflectance and high thermal infrared reflectance. The high metal volume fraction cermet layer has a metal-like optical behaviour in the thermal infrared wavelength range and makes the largest contribution to the increase of emittance compared with that of the metal

  5. Broad-band anti-reflection coupler for a : Si thin-film solar cell

    International Nuclear Information System (INIS)

    Lo, S.-S.; Chen, C.-C.; Garwe, Frank; Pertch, Thomas

    2007-01-01

    This work numerically demonstrates a new anti-reflection coupler (ARC) with high coupling efficiency in a Si substrate solar cell. The ARC in which the grating is integrated on a glass encapsulation and a three-layer impedance match layer is proposed. A coupling efficiency of 90% is obtained at wavelengths between 350 and 1200 nm in the TE and TM modes when the incident angle is less than 30 0 . In comparison with a 1μm absorber layer, the integrated absorption of an a-Si thin-film solar cell without a new ARC is doubled, at long wavelengths (750 nm ≤ λ ≤ 1200 nm), as calculated by FDTD method

  6. Triple Layer Antireflection Design Concept for the Front Side of c-Si Heterojunction Solar Cell Based on the Antireflective Effect of nc-3C-SiC:H Emitter Layer

    Directory of Open Access Journals (Sweden)

    Erick Omondi Ateto

    2016-01-01

    Full Text Available We investigated the antireflective (AR effect of hydrogenated nanocrystalline cubic silicon carbide (nc-3C-SiC:H emitter and its application in the triple layer AR design for the front side of silicon heterojunction (SHJ solar cell. We found that the nc-3C-SiC:H emitter can serve both as an emitter and antireflective coating for SHJ solar cell, which enables us to realize the triple AR design by adding one additional dielectric layer to normally used SHJ structure with a transparent conductive oxide (TCO and an emitter layer. The optimized SHJ structure with the triple layer AR coating (LiF/ITO/nc-3C-SiC:H exhibit a short circuit current density (Jsc of 38.65 mA/cm2 and lower reflectivity of about 3.42% at wavelength range of 300 nm–1000 nm.

  7. Fabrication and performance of polymer-nanocomposite anti-reflective thin films deposited by RIR-MAPLE

    Science.gov (United States)

    Singaravelu, S.; Mayo, D. C.; Park, H. K.; Schriver, K. E.; Klopf, J. M.; Kelley, M. J.; Haglund, R. F.

    2014-07-01

    Design of polymer anti-reflective (AR) optical coatings for plastic substrates is challenging because polymers exhibit a relatively narrow range of refractive indices. Here, we report synthesis of a four-layer AR stack using hybrid polymer:nanoparticle materials deposited by resonant infrared matrix-assisted pulsed laser evaporation. An Er:YAG laser ablated frozen solutions of a high-index composite containing TiO2 nanoparticles and poly(methyl-methacrylate) (PMMA), alternating with a layer of PMMA. The optimized AR coatings, with thicknesses calculated using commercial software, yielded a coating for polycarbonate with transmission over 97 %, scattering nanocomposite.

  8. Analysis of an anti-reflecting nanowire transparent electrode for solar cells

    Science.gov (United States)

    Zhao, Zhexin; Wang, Ken Xingze; Fan, Shanhui

    2017-03-01

    Transparent electrodes are an important component in many optoelectronic devices, especially solar cells. In this paper, we investigate a nanowire transparent electrode that also functions as an anti-reflection coating for silicon solar cells, taking into account the practical constraints that the electrode is typically encapsulated and needs to be in electric contact with the semiconductor. Numerical simulations show that the electrode can provide near-perfect broadband anti-reflection over much of the frequency range above the silicon band gap for both polarizations while keeping the sheet resistance sufficiently low. To provide insights into the physics mechanism of this broadband anti-reflection, we introduce a generalized Fabry-Perot model, which captures the effects of the higher order diffraction channels as well as the modification of the reflection coefficient of the interface introduced by the nanowires. This model is validated using frequency-domain electromagnetic simulations. Our work here provides design guidelines for nanowire transparent electrode in a device configuration that is relevant for solar cell applications.

  9. Multifunctional high-reflective and antireflective layer systems with easy-to-clean properties

    International Nuclear Information System (INIS)

    Gloess, D.; Frach, P.; Gottfried, C.; Klinkenberg, S.; Liebig, J.-S.; Hentsch, W.; Liepack, H.; Krug, M.

    2008-01-01

    High-reflective (HR) and even more antireflective (AR) layer systems are in use for widespread applications. Multifunctional layer systems providing high optical functionality with an easy-to-clean or a self-cleaning behaviour would be preferable for many applications to avoid soiling of the surface. In this paper, the feasibility of fabrication by highly productive pulse magnetron sputtering in an in-line coating plant is investigated. Easy-to-clean properties are achieved by a top layer of photocatalytic and photoinduced hydrophilic TiO 2 . Multifunctional HR layer systems were successfully deposited on glass and polyethylene terephthalate (PET) substrates at a low deposition temperature of 150 deg. C, demonstrating the possibility of coating certain polymer materials. Double-sided multifunctional AR layer systems with a single-sided photoinduced hydrophilic TiO 2 top coating have a resulting reflectivity of about 3% and transmittance of about 97% in the visible range of light

  10. Impedance spectroscopy of heterojunction solar cell a-SiC/c-Si with ITO antireflection film investigated at different temperatures

    International Nuclear Information System (INIS)

    Šály, V; Pern, M; Janíček, F; Mikolášek, M; Packa, J; Huran, J

    2017-01-01

    Progressive smart photovoltaic technologies including heterostructures a-SiC/c-Si with ITO antireflection film are one of the prospective replacements of conventional photovoltaic silicon technology. Our paper is focused on the investigation of heterostructures a-SiC/c-Si provided with a layer of ITO (indium oxide/tin oxide 90/10 wt.%) which acts as a passivating and antireflection coating. Prepared photovoltaic cell structure was investigated at various temperatures and the influence of temperature on its operation was searched. The investigation of the dynamic properties of heterojunction PV cells was carried out using impedance spectroscopy. The equivalent AC circuit which approximates the measured impedance data was proposed. Assessment of the influence of the temperature on the operation of prepared heterostructure was carried out by analysis of the temperature dependence of AC equivalent circuit elements. (paper)

  11. Impedance spectroscopy of heterojunction solar cell a-SiC/c-Si with ITO antireflection film investigated at different temperatures

    Science.gov (United States)

    Šály, V.; Perný, M.; Janíček, F.; Huran, J.; Mikolášek, M.; Packa, J.

    2017-04-01

    Progressive smart photovoltaic technologies including heterostructures a-SiC/c-Si with ITO antireflection film are one of the prospective replacements of conventional photovoltaic silicon technology. Our paper is focused on the investigation of heterostructures a-SiC/c-Si provided with a layer of ITO (indium oxide/tin oxide 90/10 wt.%) which acts as a passivating and antireflection coating. Prepared photovoltaic cell structure was investigated at various temperatures and the influence of temperature on its operation was searched. The investigation of the dynamic properties of heterojunction PV cells was carried out using impedance spectroscopy. The equivalent AC circuit which approximates the measured impedance data was proposed. Assessment of the influence of the temperature on the operation of prepared heterostructure was carried out by analysis of the temperature dependence of AC equivalent circuit elements.

  12. Questionable effects of antireflective coatings on inefficiently cooled solar cells

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Galster, Georg; Larsen, Esben

    1998-01-01

    of the output power and efficiency curves throughout the day the coherence between technical parameters of the solar cells and the climate in the operation region is observed and examined. It is shown how the drop in output power around noon can be avoided by fitting technical parameters of the solar cells......A model for temperature effects in p-n junction solar cells is introduced. The temperature of solar cells and the losses in the solar cell junction region caused by elevating temperature are discussed. The model developed is examined for low-cost silicon solar cells. In order to improve the shape...

  13. Broadband antireflection nanodome structures on SiC substrate

    DEFF Research Database (Denmark)

    Ou, Yiyu; Zhu, Xiaolong; Møller, Uffe Visbech

    2013-01-01

    Nanodome structures are demonstrated on the SiC substrate by using nanosphere lithography and dry etching. Significant surface antireflection has been observed over a broad spectral range from 400 nm to 1600 nm....

  14. Mechanical comparison of a polymer nanocomposite to a ceramic thin-film anti-reflective filter

    International Nuclear Information System (INIS)

    Druffel, Thad; Geng Kebin; Grulke, Eric

    2006-01-01

    Thin-film filters on optical components have been in use for decades and, for those industries utilizing a polymer substrate, the mismatch in mechanical behaviour has caused problems. Surface damage including scratches and cracks induces haze on the optical filter, reducing the transmission of the optical article. An in-mold anti-reflective (AR) filter incorporating 1/4-wavelength thin films based on a polymer nanocomposite is outlined here and compared with a traditional vacuum deposition AR coating. Nanoindentation and nanoscratch techniques are used to evaluate the mechanical properties of the thin films. Scanning electron microscopy (SEM) images of the resulting indentations and scratches are then compared to the force deflection curves to further explain the phenomena. The traditional coatings fractured by brittle mechanisms during testing, increasing the area of failure, whereas the polymer nanocomposite gave ductile failure with less surface damage

  15. Mechanical comparison of a polymer nanocomposite to a ceramic thin-film anti-reflective filter.

    Science.gov (United States)

    Druffel, Thad; Geng, Kebin; Grulke, Eric

    2006-07-28

    Thin-film filters on optical components have been in use for decades and, for those industries utilizing a polymer substrate, the mismatch in mechanical behaviour has caused problems. Surface damage including scratches and cracks induces haze on the optical filter, reducing the transmission of the optical article. An in-mold anti-reflective (AR) filter incorporating 1/4-wavelength thin films based on a polymer nanocomposite is outlined here and compared with a traditional vacuum deposition AR coating. Nanoindentation and nanoscratch techniques are used to evaluate the mechanical properties of the thin films. Scanning electron microscopy (SEM) images of the resulting indentations and scratches are then compared to the force deflection curves to further explain the phenomena. The traditional coatings fractured by brittle mechanisms during testing, increasing the area of failure, whereas the polymer nanocomposite gave ductile failure with less surface damage.

  16. Porous Nanomaterials for Ultrabroadband Omnidirectional Anti-Reflection Surfaces with Applications in High Concentration Photovoltaics

    KAUST Repository

    Yao, Yuan

    2016-12-06

    Materials for nanoporous coatings that exploit optimized chemistries and self-assembly processes offer capabilities to reach ≈98% transmission efficiency and negligible scattering losses over the broad wavelength range of the solar spectrum from 350 nm to 1.5 μm, on both flat and curved glass substrates. These nanomaterial anti-reflection coatings also offer wide acceptance angles, up to ±40°, for both s- and p-polarization states of incident light. Carefully controlled bilayer films have allowed for the fabrication of dual-sided, gradient index profiles on plano-convex lens elements. In concentration photovoltaics platforms, the resultant enhancements in the photovoltaics efficiencies are ≈8%, as defined by experimental measurements on systems that use microscale triple-junction solar cells. These materials and their applications in technologies that require control over interface reflections have the potential for broad utility in imaging systems, photolithography, light-emitting diodes, and display technologies.

  17. Pressing of three-layer, dry-formed MDF with binderless hardboard faces

    Science.gov (United States)

    Otto Suchsland; George E. Woodson; Charles W. McMillin

    1986-01-01

    Severely cooked Masonite pulp was used as face material in three-layer experimental medium-density fiberboard (MDF). The core layer consisted of conventional MDF furnish with resin binder added. The faces were formed absolutely dry without additives of any kind. The three-layer mat was hot-pressed to overall densities ranging from 44 to 56 pcf. The faces had hardboard-...

  18. Optical thin films and coatings from materials to applications

    CERN Document Server

    Flory, Francois

    2013-01-01

    Optical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. This book provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas.$bOptical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. Optical thin films and coatings provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas. Part one explores the design and manufacture of optical coatings. Part two highlights unconventional features of optical thin films including scattering properties of random structures in thin films, optical properties of thin film materials at short wavelengths, thermal properties and colour effects. Part three focusses on novel materials for optical thin films and coatings...

  19. Simple, Fast, and Cost-Effective Fabrication of Wafer-Scale Nanohole Arrays on Silicon for Antireflection

    Directory of Open Access Journals (Sweden)

    Di Di

    2014-01-01

    Full Text Available A simple, fast, and cost-effective method was developed in this paper for the high-throughput fabrication of nanohole arrays on silicon (Si, which is utilized for antireflection. Wafer-scale polystyrene (PS monolayer colloidal crystal was developed as templates by spin-coating method. Metallic shadow mask was prepared by lifting off the oxygen etched PS beads from the deposited chromium film. Nanohole arrays were fabricated by Si dry etching. A series of nanohole arrays were fabricated with the similar diameter but with different depth. It is found that the maximum depth of the Si-hole was determined by the diameter of the Cr-mask. The antireflection ability of these Si-hole arrays was investigated. The results show that the reflection decreases with the depth of the Si-hole. The deepest Si-hole arrays show the best antireflection ability (reflection 600 nm, which was about 28 percent of the nonpatterned silicon wafer’s reflection. The proposed method has the potential for high-throughput fabrication of patterned Si wafer, and the low reflectivity allows the application of these wafers in crystalline silicon solar cells.

  20. Modified geometry three-layered tablet as a platform for class II ...

    African Journals Online (AJOL)

    Modified geometry three-layered tablet as a platform for class II drugs zero-order release system. Abdullah Monahi Albogami, Mustafa E. Omer, Abdulkareem M. Al Bekairy, Abdulmalik Alkatheri, Alaa Eldeen B. Yassin ...

  1. Coatings and Tints of Spectacle Lenses

    Directory of Open Access Journals (Sweden)

    H. Zeki Büyükyıldız

    2012-10-01

    Full Text Available Spectacle lenses are made of mineral or organic (plastic materials. Various coatings and tints are applied to the spectacle lenses according to the characteristic of the lens material, and for the personal needs and cosmetic purpose. The coatings may be classified in seven groups: 1 Anti-reflection coatings, 2 Hard coatings, 3 Clean coat, 4 Mirror coatings, 5 Color tint coating (one of coloring processes, 6 Photochromic coating (one of photochromic processes, and 7 Anti-fog coatings. Anti-reflection coatings reduce unwanted reflections from the lens surfaces and increase light transmission. Hard coatings are applied for preventing the plastic lens surface from scratches and abrasion. Hard coatings are not required for the mineral lenses due to their hardness. Clean coat makes the lens surface smooth and hydrophobic. Thus, it prevents the adherence of dust, tarnish, and dirt particles on the lens surface. Mirror coatings are applied onto the sunglasses for cosmetic purpose. Color tinted and photochromic lenses are used for sun protection and absorption of the harmful UV radiations. Anti-fog coatings make the lens surface hydrophilic and prevent the coalescence of tiny water droplets on the lens surface that reduces light transmission. (Turk J Ophthalmol 2012; 42: 359-69

  2. One-Pot Fabrication of Antireflective/Antibacterial Dual-Function Ag NP-Containing Mesoporous Silica Thin Films.

    Science.gov (United States)

    Wang, Kaikai; He, Junhui

    2018-04-04

    Thin films that integrate antireflective and antibacterial dual functions are not only scientifically interesting but also highly desired in many practical applications. Unfortunately, very few studies have been devoted to the preparation of thin films with both antireflective and antibacterial properties. In this study, mesoporous silica (MSiO 2 ) thin films with uniformly dispersed Ag nanoparticles (Ag NPs) were prepared through a one-pot process, which simultaneously shows high transmittance, excellent antibacterial activity, and mechanical robustness. The optimal thin-film-coated glass substrate demonstrates a maximum transmittance of 98.8% and an average transmittance of 97.1%, respectively, in the spectral range of 400-800 nm. The growth and multiplication of typical bacteria, Escherichia coli ( E. coli), were effectively inhibited on the coated glass. Pencil hardness test, tape adhesion test, and sponge washing test showed favorable mechanical robustness with 5H pencil hardness, 5A grade adhesion, and functional durability of the coating, which promises great potential for applications in various touch screens, windows for hygiene environments, and optical apparatuses for medical uses such as endoscope, and so on.

  3. Fabrication and performance of polymer-nanocomposite anti-reflective thin films deposited by RIR-MAPLE

    Energy Technology Data Exchange (ETDEWEB)

    Singaravelu, S.; Mayo, D. C.; Park, H-. K.; Schriver, K. E.; Klopf, John M. [W& M, JLAB; Kelley, Michael J. [W& M; Haglund, R. F. [VANDERBILT

    2014-07-01

    Design of polymer anti-reflective (AR) optical coatings for plastic substrates is challenging because polymers exhibit a relatively narrow range of refractive indices. Here, we report synthesis of a four-layer AR stack using hybrid polymer: nanoparticle materials deposited by resonant infrared matrix-assisted pulsed laser evaporation. An Er: YAG laser ablated frozen solutions of a high-index composite containing TiO2 nanoparticles and poly(methylmethacrylate) (PMMA), alternating with a layer of PMMA. The optimized AR coatings, with thicknesses calculated using commercial software, yielded a coating for polycarbonate with transmission over 97 %, scattering <3 %, and a reflection coefficient below 0.5 % across the visible range, with a much smaller number of layers than would be predicted by a standard thin film calculation. The TiO2 nanoparticles contribute more to the enhanced refractive index of the high-index layers than can be accounted for by an effective medium model of the nanocomposite.

  4. An Antireflective Nanostructure Array Fabricated by Nanosilver Colloidal Lithography on a Silicon Substrate

    Directory of Open Access Journals (Sweden)

    Park Seong-Je

    2010-01-01

    Full Text Available Abstract An alternative method is presented for fabricating an antireflective nanostructure array using nanosilver colloidal lithography. Spin coating was used to produce the multilayered silver nanoparticles, which grew by self-assembly and were transformed into randomly distributed nanosilver islands through the thermodynamic action of dewetting and Oswald ripening. The average size and coverage rate of the islands increased with concentration in the range of 50–90 nm and 40–65%, respectively. The nanosilver islands were critically affected by concentration and spin speed. The effects of these two parameters were investigated, after etching and wet removal of nanosilver residues. The reflection nearly disappeared in the ultraviolet wavelength range and was 17% of the reflection of a bare silicon wafer in the visible range.

  5. New temperable solar coatings: Tempsol

    Science.gov (United States)

    Demiryont, Hulya

    2001-11-01

    This paper deals with the large area deposition and coating properties of the thermo-stable (temperable/bendable) solar coating material, CuO, and some new optical coating systems comprising CuO films for architectural and automotive/transportation applications. The CuO solar coating is combined with other coating layers, for example, an anti-reflection film, a reflection film, a coloration coating layer, etc., which are also thermo-stable. The film systems are developed at the research laboratory by D.C. Magnetron reactive sputtering process. The new developed technologies then transferred to the production line. Product performances are compared before and after heat treatment of the coating systems. Performance tables and other physical properties, including optical parameters, mechanical and environmental stability, storage properties, etc., are also presented for this new product series.

  6. Analysis of Nanoparticle Additive Couple Stress Fluids in Three-layered Journal Bearing

    International Nuclear Information System (INIS)

    Rao, T V V L N; Sufian, S; Mohamed, N M

    2013-01-01

    The present theoretical study investigates the load capacity and friction coefficient in a three-layered journal bearing lubricated with nanoparticle additive couple stress fluids. The couple stresses effects are analyzed based on Stokes micro-continuum theory. The nondimensional pressure and shear stress expressions are derived using modified Reynolds equation. The nondimensional load capacity increases and the coefficient of friction decreases using nanoparticle additive lubricants with couple stress effects. The three-layered journal bearing performance characteristics are improved with increase in both (i) surface adsorbent fluid film layer thickness and (ii) dynamic viscosity ratio of surface to core layer.

  7. The continuous structure bending of the three-layer plate with the lightweight aggregate

    Directory of Open Access Journals (Sweden)

    Zhuravlev Alexander

    2017-01-01

    Full Text Available This paper deals with the problem of finding the effective way to solve the task of the composite construction bending of the three-layer plate with the lightweight aggregate, which operates on a continuous pattern. The expressions for the parameters determination, regarding a reduction of support bending moments due to the shear deformation of the middle layer, are given. The three-membered structure equation, connecting three bending moments, occurring above three adjacent pillars of the continuous three-layer beam, is obtained based on the condition of the movement compatibility.

  8. One kind of atmosphere-ocean three layer model for calculating the velocity of ocean current

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Z; Xi, P

    1979-10-01

    A three-layer atmosphere-ocean model is given in this paper to calcuate the velocity of ocean current, particularly the function of the vertical coordinate, taking into consideratiln (1) the atmospheric effect on the generation of ocean current, (2) a calculated coefficient of the eddy viscosity instead of an assumed one, and (3) the sea which actually varies in depth.

  9. Surface Passivation and Antireflection Behavior of ALD on n-Type Silicon for Solar Cells

    Directory of Open Access Journals (Sweden)

    Ing-Song Yu

    2013-01-01

    Full Text Available Atomic layer deposition, a method of excellent step coverage and conformal deposition, was used to deposit TiO2 thin films for the surface passivation and antireflection coating of silicon solar cells. TiO2 thin films deposited at different temperatures (200°C, 300°C, 400°C, and 500°C on FZ n-type silicon wafers are in the thickness of 66.4 nm ± 1.1 nm and in the form of self-limiting growth. For the properties of surface passivation, Si surface is effectively passivated by the 200°C deposition TiO2 thin film. Its effective minority carrier lifetime, measured by the photoconductance decay method, is improved 133% at the injection level of  cm−3. Depending on different deposition parameters and annealing processes, we can control the crystallinity of TiO2 and find low-temperature TiO2 phase (anatase better passivation performance than the high-temperature one (rutile, which is consistent with the results of work function measured by Kelvin probe. In addition, TiO2 thin films on polished Si wafer serve as good ARC layers with refractive index between 2.13 and 2.44 at 632.8 nm. Weighted average reflectance at AM1.5G reduces more than half after the deposition of TiO2. Finally, surface passivation and antireflection properties of TiO2 are stable after the cofire process of conventional crystalline Si solar cells.

  10. Graphene-Tapered ZnO Nanorods Array as a Flexible Antireflection Layer

    Directory of Open Access Journals (Sweden)

    Taeseup Song

    2015-01-01

    Full Text Available Flexible solar cells have drawn a great deal of attention due to their various advantages including deformable and wearable characteristics. In the solar cells, the antireflection layer plays an important role in the improvement in the conversion efficiency by increasing the light transmission and suppressing the Fresnel refraction. For the successful implantation of the antireflection layer into the flexible solar cells, the flexible mechanical property of the antireflection layer is also necessary. However, the study on flexible antireflection layer for the flexible solar cells or optoelectronics is still lacking. In this study, we report the graphene-tapered ZnO nanorods array as a flexible antireflection layer for the application in flexible solar cells. Flexible two-dimensional graphene sheet and the tapered morphology of ZnO nanorods enable conformal coverage on the flexible substrate with curved surface and significant improvements in antireflection properties, respectively.

  11. Optical coatings for laser fusion applications

    International Nuclear Information System (INIS)

    Lowdermilk, W.H.; Milam, D.; Rainer, F.

    1980-01-01

    Lasers for fusion experiments use thin-film dielectric coatings for reflecting, antireflecting and polarizing surface elements. Coatings are most important to the Nd:glass laser application. The most important requirements of these coatings are accuracy of the average value of reflectance and transmission, uniformity of amplitude and phase front of the reflected or transmitted light, and laser damage threshold. Damage resistance strongly affects the laser's design and performance. The success of advanced lasers for future experiments and for reactor applications requires significant developments in damage resistant coatings for ultraviolet laser radiation

  12. Graded index and randomly oriented core-shell silicon nanowires for broadband and wide angle antireflection

    Directory of Open Access Journals (Sweden)

    P. Pignalosa

    2011-09-01

    Full Text Available Antireflection with broadband and wide angle properties is important for a wide range of applications on photovoltaic cells and display. The SiOx shell layer provides a natural antireflection from air to the Si core absorption layer. In this work, we have demonstrated the random core-shell silicon nanowires with both broadband (from 400nm to 900nm and wide angle (from normal incidence to 60º antireflection characteristics within AM1.5 solar spectrum. The graded index structure from the randomly oriented core-shell (Air/SiOx/Si nanowires may provide a potential avenue to realize a broadband and wide angle antireflection layer.

  13. Three layer model analysis on two-phase critical flow through a converging nozzle

    International Nuclear Information System (INIS)

    Ochi, J.; Ayukawa, K.

    1991-01-01

    A three layer model is proposed for a two-phase critical flow through a converging nozzle in this paper. Most previous analyses of the two phase flow have been based on a homogeneous or a separated flow model as the conservation equations. These results were found to have large deviations from the actual measurements for two phase critical flows. The presented model is based on the assumption that a flow consists of three layers with a mixing region between gas and liquid phase layers. The effect of gas and liquid fraction occupied in the mixing layer was made clear from the numerical results. The measurements of the critical flow rate and the pressure profiles through a converging nozzle were made with air-water flow. The calculated results of these models are discussed in comparison with the experimental data for the flow rates and the pressure distributions under critical conditions

  14. A three-layer distributed RC network with two transmission zeros

    Science.gov (United States)

    Huelsman, L. P.

    1974-01-01

    This report describes the properties of a three-layer distributed RC network consisting of two resistive layers separated by a dielectric which may be used to realize two zeros of transmission on the j-omega axis of the complex frequency plane. The relative location of the two zeros is controlled by the location of a contact placed on one of the resistive layers.

  15. The Research of Clinical Decision Support System Based on Three-Layer Knowledge Base Model

    Directory of Open Access Journals (Sweden)

    Yicheng Jiang

    2017-01-01

    Full Text Available In many clinical decision support systems, a two-layer knowledge base model (disease-symptom of rule reasoning is used. This model often does not express knowledge very well since it simply infers disease from the presence of certain symptoms. In this study, we propose a three-layer knowledge base model (disease-symptom-property to utilize more useful information in inference. The system iteratively calculates the probability of patients who may suffer from diseases based on a multisymptom naive Bayes algorithm, in which the specificity of these disease symptoms is weighted by the estimation of the degree of contribution to diagnose the disease. It significantly reduces the dependencies between attributes to apply the naive Bayes algorithm more properly. Then, the online learning process for parameter optimization of the inference engine was completed. At last, our decision support system utilizing the three-layer model was formally evaluated by two experienced doctors. By comparisons between prediction results and clinical results, our system can provide effective clinical recommendations to doctors. Moreover, we found that the three-layer model can improve the accuracy of predictions compared with the two-layer model. In light of some of the limitations of this study, we also identify and discuss several areas that need continued improvement.

  16. Natural convection of the oxide pool in a three-layer configuration of core melts

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su-Hyeon; Park, Hae-Kyun; Chung, Bum-Jin, E-mail: bjchung@khu.ac.kr

    2017-06-15

    Highlights: • Natural convection of oxide pool in 3-layer configuration during IVR was investigated. • High Ra was achieved by using mass transfer experiments based on analogy concept. • Heat ratio to light metal layer was 14% higher for 3-layer configuration than 2-layer one. • Heat transfer to heavy metal layer was poor and hence heat load to side wall increased. • Angular heat loads to side wall showed strengthened heat focusing at uppermost location. - Abstract: We investigated the natural convection of the oxide layer in a three-layer configuration of core melts in a severe accident. In order to achieve high modified Rayleigh numbers of 10{sup 12}–10{sup 13}, mass transfer experiments were performed using a copper sulfate electroplating system based upon the analogy between heat and mass transfer. Four different cooling conditions of the top and the bottom plates were tested. The upward heat ratios were 14% higher for three-layer than for two-layer due to the reduced heights and the downward heat ratios were lower the same amount. The local Nusselt numbers for the top and the bottom plates were measured and compared with the two layer configuration. To explore the heat load to the reactor vessel, the angle-dependent heat fluxes at the side wall, were measured and compared with the two-layer configuration. Heat load to the side wall and peak heat at the uppermost location were intensified for the three-layer configuration.

  17. Self-organized, effective medium black silicon antireflection structures for silicon optics in the mid-infrared

    Science.gov (United States)

    Steglich, Martin; Käsebier, Thomas; Kley, Ernst-Bernhard; Tünnermann, Andreas

    2016-09-01

    Thanks to its high quality and low cost, silicon is the material of choice for optical devices operating in the mid-infrared (MIR; 2 μm to 6 μm wavelength). Unfortunately in this spectral region, the refractive index is comparably high (about 3.5) and leads to severe reflection losses of about 30% per interface. In this work, we demonstrate that self-organized, statistical Black Silicon structures, fabricated by Inductively Coupled Plasma Reactive Ion Etching (ICP-RIE), can be used to effectively suppress interface reflection. More importantly, it is shown that antireflection can be achieved in an image-preserving, non-scattering way. This enables Black Silicon antireflection structures (ARS) for imaging applications in the MIR. It is demonstrated that specular transmittances of 97% can be easily achieved on both flat and curved substrates, e.g. lenses. Moreover, by a combined optical and morphological analysis of a multitude of different Black Silicon ARS, an effective medium criterion for the examined structures is derived that can also be used as a design rule for maximizing sample transmittance in a desired wavelength range. In addition, we show that the mechanical durability of the structures can be greatly enhanced by coating with hard dielectric materials like diamond-like carbon (DLC), hence enabling practical applications. Finally, the distinct advantages of statistical Black Silicon ARS over conventional AR layer stacks are discussed: simple applicability to topological substrates, absence of thermal stress and cost-effectiveness.

  18. Plasticity and fracture modeling of three-layer steel composite Tribond® 1200 for crash simulation

    NARCIS (Netherlands)

    Eller, Tom; Ramaker, Kenny; Greve, Lars; Andres, M.T.; Hazrati Marangalou, Javad; van den Boogaard, Antonius H.

    2017-01-01

    A constitutive model is presented for the three-layer steel composite Tribond® 1200. Tribond® is a hot forming steel which consists of three layers: a high strength steel core between two outer layers of ductile low strength steel. The model is designed to provide an accurate prediction of the

  19. The amplitude modulation of laser diode emission with antireflection piezo films on mirrors

    International Nuclear Information System (INIS)

    Abrarov, S.M.; Karimov, Kh.S.; Akhmedov, Kh.M.

    2001-01-01

    Present article is devoted to amplitude modulation of laser diode emission with antireflection piezo films on mirrors. The modulator based on laser diode and the emission amplitude modulation of which is performed by electric field impact on antireflection piezo films applied on mirrors was studied.

  20. Energy efficient three-layer panels and elastic compliance of their middle layer

    Directory of Open Access Journals (Sweden)

    Petrov Stanislav

    2017-01-01

    Full Text Available Three-layer panels are referred to light weight energy efficient building envelopes. According to current trends, mineral wool from basalt fiber is preferable to be used as panels middle layer. All three-layers of the construction together account for mechanical properties, though these layers taken separately have very different mechanical properties. The work of such a composite design has a number of features that require careful consideration when calculating the panels for strength. Thus, it has not yet been described how squeeze reduction of a relatively soft middle layer affects the load bearing capacity of a panel. When panels are exposed to external loads, their middle layer is squeezed thus changing the characteristics of the panel. This effect is particularly evident in supporting structures. Besides, squeeze reduction of the middle layer changes its elastic-plastic propeties. The purpose of this work is to study the effect of the middle layer of an energy efficient panel squeeze reduction on its load bearing capacity. When solving this task, the authors worked out a methodology which takes into account squeeze reduction of a middle layer and its effect on load bearing capacity of the panel. The researches introduced an algorithm for solving this task and created a tool that allows to easily receive the exact solution. The paper presents this methodology and describes a computer program for calculating three-layer panels with account of changing elastic compliance of a middle layer. The main result of the work is an extended methodology of calculation of the panels and an obtained engineering tool that allows to quickly obtain an extended solution.

  1. Three-layered models of Ganymede and Callisto - compositions, structures, and aspects of evolution

    International Nuclear Information System (INIS)

    Mueller, S.; Mckinnon, W.B.

    1988-01-01

    The structural models presently defined for Ganymede and Callisto, which encompass a pure-ice upper layer, a mixed ice/rock lower mantle, and a rock core, incorporate three alternative rock component candidates representing various degrees of silicate hydration and oxidation. The three-layered model facilitates close study of the radius increase required for the internal differentiation of an ice-rock satellite; such expansion is determined to be most significant early in the process, and less so as differentiation approaches completion. The probability of postaccretional melting due to radiogenic heating is calculated. 78 references

  2. Gadolinium removal from the moderator system of TAPP - 3 using the three layer bed

    International Nuclear Information System (INIS)

    Tripathi, V.S.; Balaji, V.; Venkateswaran, G.; Dash, S.C.

    2008-01-01

    Nitric acid leaching from the weak base anion (WBA) exchanger had been evaluated and based on this a 5% mixture of nitric acid loaded weak base anion exchanger with fresh weak base anion exchanger (NLWBA) at the bottom of the ion exchange column has been devised to maintain an outlet pH in the range of 5.0 to 5.5 during Gd removal from the moderator system of TAPP - 3 and 4. A three layered bed had been constituted wherein strong acid cation (SAC) exchanger is placed as the top layer while a mixed bed of SAC and WBA or pure WBA is used as the middle layer and the 5% NLWBA was used as the bottom most layer. This bed configuration would result in an iso-pH regime in the moderator system during the Gd removal along with quantitative removal of Gd. Two three-layer bed columns were prepared at TAPS - 3 and 4 in July 07. The resin was loaded in batches and after preparing the column, the column was deuterated with heavy water (> 99.75 % w/w) at a steady flow rate of 280 ml/min. After achieving high-grade isotopic purity viz. > 99.75 % w/w., these columns were preserved for their use after SDS - 2 actuation in the plant. Biennial Shut Down (BSD) of Unit - 3 was taken on 04-05-08 by SDS-2 actuation resulting in 16.37 ppm Gd in the moderator system. Gd removal to the extent about 8 mg/kg as designed could be done on one three layer bed. The use of this bed has resulted in an iso-pH regime at the column inlet and outlet. Conductivity values observed in the system were within the specifications. The three layer bed of a configuration slightly modified from the one tested in this work is expected to improve the column efficiency to 100% from the presently observed 87% and 97% respectively for the IX-2 and IX-3. (author)

  3. Thermal Advantages for Solar Heating Systems with a Glass Cover with Antireflection Surfaces

    DEFF Research Database (Denmark)

    Furbo, Simon; Shah, Louise Jivan

    2003-01-01

    Investigations elucidate how a glass cover with antireflection surfaces can improve the efficiency of a solar collector and the thermal performance of solar heating systems. The transmittances for two glass covers for a flat-plate solar collector were measured for different incidence angles....... The two glasses are identical, except for the fact that one of them is equipped with antireflection surfaces by the company SunArc A/ S. The transmittance was increased by 5–9%-points due to the antireflection surfaces. The increase depends on the incidence angle. The efficiency at incidence angles of 08...... and the incidence angle modifier were measured for a flat-plate solar collector with the two cover plates. The collector efficiency was increased by 4–6%-points due to the antireflection surfaces, depending on the incidence angle. The thermal advantage with using a glass cover with antireflection surfaces...

  4. Simulation of thermal environment in a three-layer vinyl greenhouse by natural ventilation control

    Science.gov (United States)

    Jin, Tea-Hwan; Shin, Ki-Yeol; Yoon, Si-Won; Im, Yong-Hoon; Chang, Ki-Chang

    2017-11-01

    A high energy, efficient, harmonious, ecological greenhouse has been highlighted by advanced future agricultural technology recently. This greenhouse is essential for expanding the production cycle toward growth conditions through combined thermal environmental control. However, it has a negative effect on farming income via huge energy supply expenses. Because not only production income, but operating costs related to thermal load for thermal environment control is important in farming income, it needs studies such as a harmonious ecological greenhouse using natural ventilation control. This study is simulated for energy consumption and thermal environmental conditions in a three-layered greenhouse by natural ventilation using window opening. A virtual 3D model of a three-layered greenhouse was designed based on the real one in the Gangneung area. This 3D model was used to calculate a thermal environment state such as indoor temperature, relative humidity, and thermal load in the case of a window opening rate from 0 to 100%. There was also a heat exchange operated for heating or cooling controlled by various setting temperatures. The results show that the cooling load can be reduced by natural ventilation control in the summer season, and the heat exchange capacity for heating can also be simulated for growth conditions in the winter season.

  5. Time-difference imaging of magnetic induction tomography in a three-layer brain physical phantom

    International Nuclear Information System (INIS)

    Liu, Ruigang; Li, Ye; Fu, Feng; You, Fusheng; Shi, Xuetao; Dong, Xiuzhen

    2014-01-01

    Magnetic induction tomography (MIT) is a contactless and noninvasive technique to reconstruct the conductivity distribution in a human cross-section. In this paper, we want to study the feasibility of imaging the low-contrast perturbation and small volume object in human brains. We construct a three-layer brain physical phantom which mimics the real conductivity distribution of brains by introducing an artificial skull layer. Using our MIT data acquisition system on this phantom and differential algorithm, we have obtained a series of reconstructed images of conductivity perturbation objects. All of the conductivity perturbation objects in the brain phantom can be clearly distinguished in the reconstructed images. The minimum detectable conductivity difference between the object and the background is 0.03 S m −1  (12.5%). The minimum detectable inner volume of the objects is 3.4 cm 3 . The three-layer brain physical phantom is able to simulate the conductivity distribution of the main structures of a human brain. The images of the low-contrast perturbation and small volume object show the prospect of MIT in the future. (paper)

  6. Simulation of thermal environment in a three-layer vinyl greenhouse by natural ventilation control

    Directory of Open Access Journals (Sweden)

    Jin Tea-Hwan

    2017-01-01

    Full Text Available A high energy, efficient, harmonious, ecological greenhouse has been highlighted by advanced future agricultural technology recently. This greenhouse is essential for expanding the production cycle toward growth conditions through combined thermal environmental control. However, it has a negative effect on farming income via huge energy supply expenses. Because not only production income, but operating costs related to thermal load for thermal environment control is important in farming income, it needs studies such as a harmonious ecological greenhouse using natural ventilation control. This study is simulated for energy consumption and thermal environmental conditions in a three-layered greenhouse by natural ventilation using window opening. A virtual 3D model of a three-layered greenhouse was designed based on the real one in the Gangneung area. This 3D model was used to calculate a thermal environment state such as indoor temperature, relative humidity, and thermal load in the case of a window opening rate from 0 to 100%. There was also a heat exchange operated for heating or cooling controlled by various setting temperatures. The results show that the cooling load can be reduced by natural ventilation control in the summer season, and the heat exchange capacity for heating can also be simulated for growth conditions in the winter season.

  7. Biomimetic nanostructures in ZnS and ZnSe provide broadband anti-reflectivity

    Science.gov (United States)

    Chan, L.; DeCuir, E. A., Jr.; Fu, R.; Morse, D. E.; Gordon, M. J.

    2017-11-01

    Graded-index, moth eye-inspired anti-reflective features were fabricated in ZnS and ZnSe via nanosphere lithography using a Langmuir-Blodgett dip-coating method with plasma-based mask reduction and pattern transfer. Arrays of hexagonally close-packed conical frusta (top diameter = 300 nm, pitch = 690 nm, height = 2800 nm) were realized by isotropic etching (size-reduction) of the colloidal mask with CF4/Ar, followed by pattern transfer into the substrate using CH4/H2 plasma etching. Substantial increases in broadband transmission were achieved across the 2-20 μm range, yielding 23% and 26% single-side transmission improvement, and 92% and 88% absolute double-side transmission for ZnS and ZnSe, respectively, in excellent agreement with finite difference time domain (FDTD) optical simulations. Experimental differences in direct versus total transmission, and the general fall off of transmission at short wavelengths, were attributed to diffuse forward scattering and diffractive effects, as predicted by far-field scattering patterns using FDTD. The fabrication method presented can be used to enhance efficiency for multiple IR applications by minimizing reflective losses, while offering the further advantages of scalability and low cost.

  8. In Vivo Evaluation of Short-Term Performance of New Three-Layer Collagen-Based Vascular Graft Designed for Low-Flow Peripheral Vascular Reconstructions

    Directory of Open Access Journals (Sweden)

    Tomas Grus

    2018-01-01

    Full Text Available Aim. The aim of this study was to evaluate short-term patency of the new prosthetic graft and its structural changes after explantation. Methods. The study team developed a three-layer conduit composed of a scaffold made from polyester coated with collagen from the inner and outer side with an internal diameter of 6 mm. The conduit was implanted as a bilateral bypass to the carotid artery in 7 sheep and stenosis was created in selected animals. After a period of 161 days, the explants were evaluated as gross and microscopic specimens. Results. The initial flow rate (median ± IQR in grafts with and without artificial stenosis was 120±79 ml/min and 255±255 ml/min, respectively. Graft occlusion occurred after 99 days in one of 13 conduits (patency rate: 92%. Wall-adherent thrombi occurred only in sharp curvatures in two grafts. Microscopic evaluation showed good engraftment and preserved structure in seven conduits; inflammatory changes with foci of bleeding, necrosis, and disintegration in four conduits; and narrowing of the graft due to thickening of the wall with multifocal separation of the outer layer in two conduits. Conclusions. This study demonstrates good short-term patency rates of a newly designed three-layer vascular graft even in low-flow conditions in a sheep model.

  9. ZnO/Al{sub 2}O{sub 3} core/shell nanorods array as excellent anti-reflection layers on silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lung, Chun-Ming; Wang, Wei-Cheng [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (China); Chen, Ching-Hsiang [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei, 106, Taiwan (China); Chen, Liang-Yih, E-mail: sampras@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei, 106, Taiwan (China); Chen, Miin-Jang, E-mail: mjchen@ntu.edu.tw [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (China)

    2016-09-01

    A simple, low-temperature hydrothermal method and atomic layer deposition (ALD) were used to fabricate ZnO nanostructures as subwavelength-structure antireflection layers (SWS ARLs) on Si solar cells. ZnO seed layers with wafer-scale uniformity were prepared, and ALD was used to reproduce two types of ZnO-based structures, nanorod arrays (NRAs) and nanotip arrays (NTAs). The study examined diammonium phosphate concentrations during growth, conducted simulations based on three-dimensional finite-difference time-domain and reflection analyses, performed X-ray diffractometer, field-emission scanning electron microscope, and high-resolution transmission electron microscope characterizations, measured total reflectance spectra by using a spectrophotometer with integrated spheres, and ran solar simulations to determine the efficiency of the Si solar cells. Coating the ZnO NTAs on the Si solar cells yielded a low total reflectance over a broad band range and produced omnidirectional light scattering on the cells, causing incident light to have a shallow penetration depth near the p–n junction and leading to an increase in short current density ({sub Jsc}). Coating the ZnO NTAs with an Al{sub 2}O{sub 3} shell induced continuous variation in the refractive index, further decreasing the total reflectance to approximately 5.5%, and protected the ZnO NTAs from the harmful acidic environment. Significantly increasing the J{sub sc} and η levels of the Si solar cells, the Al{sub 2}O{sub 3}@ZnO-NTA antireflection structure produced a high efficiency of 17.79%. Its superior performance, including low and wideband reflectance, a low process temperature, and a significant increase in efficiency, indicates the potential of this antireflective structure for enhancing solar cell efficiency in photovoltaic devices. - Highlights: • ZnO nanotip arrays were synthesized by hydrothermal methods as antireflection layer. • The total reflectance is low around 7.8% from 400 nm to 1000

  10. Full-Wave Analysis of Microstrip Antennas in Three-Layered Spherical Media

    Directory of Open Access Journals (Sweden)

    Tao Yu

    2013-01-01

    Full Text Available A model of three-layered spherical microstrip antenna has been analyzed based on Rao-Wilton-Glisson (RWG triangular basis functions using mixed potential integral equation (MPIE. Firstly, the model of antenna and the dyadic Green’s function in spherical microstrip antennas are given at the beginning of this paper. Then, due to the infinite series convergence problem, asymptotic extraction approach is presented to accelerate the Green’s functions convergence speed when source and field points are located in the same layer and different layers. The convergence speed can be accelerated observably by using this method. Finally, in order to simplify impedance matrix elements calculation at the junction of the probe and patch, a novel division fashion of pair of triangles is adopted in this paper. The input impedance result obtained shows the validity and effectiveness of the analysis method comparing with published data.

  11. Influence of Parameters of Core Bingham Material on Critical Behaviour of Three-Layered Annular Plate

    Directory of Open Access Journals (Sweden)

    Pawlus Dorota

    2017-12-01

    Full Text Available The paper presents the dynamic response of annular three-layered plate subjected to loads variable in time. The plate is loaded in the plane of outer layers. The plate core has the electrorheological properties expressed by the Bingham body model. The dynamic stability loss of plate with elastic core is determined by the critical state parameters, particularly by the critical stresses. Numerous numerical observations show the influence of the values of viscosity constant and critical shear stresses, being the Bingham body parameters, on the supercritical viscous fluid plate behaviour. The problem has been solved analytically and numerically using the orthogonalization method and finite difference method. The solution includes both axisymmetric and asymmetric plate dynamic modes.

  12. Research on performance of three-layer MG-OXC system based on MLAG and OCDM

    Science.gov (United States)

    Wang, Yubao; Ren, Yanfei; Meng, Ying; Bai, Jian

    2017-10-01

    At present, as traffic volume which optical transport networks convey and species of traffic grooming methods increase rapidly, optical switching techniques are faced with a series of issues, such as more requests for the number of wavelengths and complicated structure management and implementation. This work introduces optical code switching based on wavelength switching, constructs the three layers multi-granularity optical cross connection (MG-OXC) system on the basis of optical code division multiplexing (OCDM) and presents a new traffic grooming algorithm. The proposed architecture can improve the flexibility of traffic grooming, reduce the amount of used wavelengths and save the number of consumed ports, hence, it can simplify routing device and enhance the performance of the system significantly. Through analyzing the network model of switching structure on multicast layered auxiliary graph (MLAG) and the establishment of traffic grooming links, and the simulation of blocking probability and throughput, this paper shows the excellent performance of this mentioned architecture.

  13. A Decomposition Method for Security Constrained Economic Dispatch of a Three-Layer Power System

    Science.gov (United States)

    Yang, Junfeng; Luo, Zhiqiang; Dong, Cheng; Lai, Xiaowen; Wang, Yang

    2018-01-01

    This paper proposes a new decomposition method for the security-constrained economic dispatch in a three-layer large-scale power system. The decomposition is realized using two main techniques. The first is to use Ward equivalencing-based network reduction to reduce the number of variables and constraints in the high-layer model without sacrificing accuracy. The second is to develop a price response function to exchange signal information between neighboring layers, which significantly improves the information exchange efficiency of each iteration and results in less iterations and less computational time. The case studies based on the duplicated RTS-79 system demonstrate the effectiveness and robustness of the proposed method.

  14. Propagation behavior of two transverse surface waves in a three-layer piezoelectric/piezomagnetic structure

    Science.gov (United States)

    Nie, Guoquan; Liu, Jinxi; Liu, Xianglin

    2017-10-01

    Propagation of transverse surface waves in a three-layer system consisting of a piezoelectric/piezomagnetic (PE/PM) bi-layer bonded on an elastic half-space is theoretically investigated in this paper. Dispersion relations and mode shapes for transverse surface waves are obtained in closed form under electrically open and shorted boundary conditions at the upper surface. Two transverse surface waves related both to Love-type wave and Bleustein-Gulyaev (B-G) type wave propagating in corresponding three-layer structure are discussed through numerically solving the derived dispersion equation. The results show that Love-type wave possesses the property of multiple modes, it can exist all of the values of wavenumber for every selected thickness ratios regardless of the electrical boundary conditions. The presence of PM interlayer makes the phase velocity of Love-type wave decrease. There exist two modes allowing the propagation of B-G type wave under electrically shorted circuit, while only one mode appears in the case of electrically open circuit. The modes of B-G type wave are combinations of partly normal dispersion and partly anomalous dispersion whether the electrically open or shorted. The existence range of mode for electrically open case is greatly related to the thickness ratios, with the thickness of PM interlayer increasing the wavenumber range for existence of B-G type wave quickly shortened. When the thickness ratio is large enough, the wavenumber range of the second mode for electrically shorted circuit is extremely narrow which can be used to remove as an undesired mode. The propagation behaviors and mode shapes of transverse surface waves can be regulated by the modification of the thickness of PM interlayer. The obtained results provide a theoretical prediction and basis for applications of PE-PM composites and acoustic wave devices.

  15. PTX-loaded three-layer PLGA/CS/ALG nanoparticle based on layer-by-layer method for cancer therapy.

    Science.gov (United States)

    Wang, Fang; Yuan, Jian; Zhang, Qian; Yang, Siqian; Jiang, Shaohua; Huang, Chaobo

    2018-05-17

    Poly (lactic-co-glycolic acid) (PLGA) nanoparticles are an ideal paclitaxel (PTX)-carrying system due to its biocompatibility and biodegradability. But it possessed disadvantage of drug burst release. In this research, a layer-by-layer deposition of chitosan (CS) and sodium alginate (ALG) was applied to modify the PLGA nanoparticles. The surface charges and morphology of the PLGA, PLGA/CS and PLGA/CS/ALG particles was measured by capillary electrophoresis and SEM and TEM, respectively. The drug encapsulation and loading efficiency were confirmed by ultraviolet spectrophotometer. The nanoparticles were stable and exhibited controlled drug release performance, with good cytotoxicity to human lung carcinoma cells (HepG 2). Cumulatively, our research suggests that this kind of three-layer nanoparticle with LbL-coated shield has great properties to act as a novel drug-loaded system.

  16. Use of ZnO as antireflective, protective, antibacterial, and biocompatible multifunction nanolayer of thermochromic VO2 nanofilm for intelligent windows

    International Nuclear Information System (INIS)

    Zhou, Huaijuan; Li, Jinhua; Bao, Shanhu; Li, Jian; Liu, Xuanyong; Jin, Ping

    2016-01-01

    Graphical abstract: - Highlights: • A multifunctional VO 2 /ZnO bilayer film is designed and deposited by magnetron sputtering apparatus. • The ZnO top layer can enhance the antireflective, antioxidative and anti-corrosion functions of the VO 2 film. • The ZnO top layer can endow VO 2 film with excellent antibacterial performance. • The ZnO top layer can attenuate the cytotoxicity of VO 2 thin film. - Abstract: A multifunctional VO 2 /ZnO bilayer film is designed and deposited by magnetron sputtering apparatus. The integration of the antireflective, antioxidative and anti-corrosion functions, and antibacterial performance makes the heterostructure film a promising candidate in the energy-saving smart window. The ZnO thin film as the antireflection layer can markedly boost the solar regulation efficiency (ΔT sol ) from 7.7% to 12.2% and possesses excellent luminous transmittance (T lum-L = 50.3%) in the low-temperature semiconductor phase. The ZnO layer as the protection barrier can not only protect VO 2 thin film from oxidation to much toxic V 2 O 5 , but also decrease the release of V ions. Besides, the synergistic effect of releasing killing by Zn 2+ ions and contact killing by ZnO NPs makes ZnO thin film an outstanding antibacterial coating. In terms of the biological safety, ZnO coating with appropriate film thickness can effectively attenuate the cytotoxicity of VO 2 on human HIBEpiC cells. We hope this work can provide new insights for better designing of novel multifunctional VO 2 -based intelligent energy-saving windows.

  17. Tunable, flexible antireflection layer of ZnO nanowires embedded in PDMS.

    Science.gov (United States)

    Kim, Min Kyu; Yi, Dong Kee; Paik, Ungyu

    2010-05-18

    In this article, we report the fabrication of ordered hybrid structures composed of ZnO nanowires and a polymeric matrix with a polymer precursor infiltrating the nanowire arrays. The antireflective properties of the resulting ZnO nanowire-embedded polydimethylsiloxane composite (ZPC) were investigated at various ZnO nanowire lengths and ZPC bending angles. Interestingly, we found that whereas the antireflective properties showed a strong dependence on the length of the embedded ZnO nanowires in PDMS, the bending of ZPC has little effect on the antireflective properties.

  18. Novel anti-reflection technology for GaAs single-junction solar cells using surface patterning and Au nanoparticles.

    Science.gov (United States)

    Kim, Youngjo; Lam, Nguyen Dinh; Kim, Kangho; Kim, Sangin; Rotermund, Fabian; Lim, Hanjo; Lee, Jaejin

    2012-07-01

    Single-junction GaAs solar cell structures were grown by low-pressure MOCVD on GaAs (100) substrates. Micro-rod arrays with diameters of 2 microm, 5 microm, and 10 microm were fabricated on the surfaces of the GaAs solar cells via photolithography and wet chemical etching. The patterned surfaces were coated with Au nanoparticles using an Au colloidal solution. Characteristics of the GaAs solar cells with and without the micro-rod arrays and Au nanoparticles were investigated. The short-circuit current density of the GaAs solar cell with 2 microm rod arrays and Au nanoparticles increased up to 34.9% compared to that of the reference cell without micro-rod arrays and Au nanoparticles. The conversion efficiency of the GaAs solar cell that was coated with Au nanoparticles on the patterned surface with micro-rod arrays can be improved from 14.1% to 19.9% under 1 sun AM 1.5G illumination. These results show that micro-rod arrays and Au nanoparticle coating can be applied together in surface patterning to achieve a novel cost-effective anti-reflection technology.

  19. A three-layer magnetic shielding for the MAIUS-1 mission on a sounding rocket

    International Nuclear Information System (INIS)

    Kubelka-Lange, André; Herrmann, Sven; Grosse, Jens; Lämmerzahl, Claus; Rasel, Ernst M.; Braxmaier, Claus

    2016-01-01

    Bose-Einstein-Condensates (BECs) can be used as a very sensitive tool for experiments on fundamental questions in physics like testing the equivalence principle using matter wave interferometry. Since the sensitivity of these experiments in ground-based environments is limited by the available free fall time, the QUANTUS project started to perform BEC interferometry experiments in micro-gravity. After successful campaigns in the drop tower, the next step is a space-borne experiment. The MAIUS-mission will be an atom-optical experiment that will show the feasibility of experiments with ultra-cold quantum gases in microgravity in a sounding rocket. The experiment will create a BEC of 10"5 "8"7Rb-atoms in less than 5 s and will demonstrate application of basic atom interferometer techniques over a flight time of 6 min. The hardware is specifically designed to match the requirements of a sounding rocket mission. Special attention is thereby spent on the appropriate magnetic shielding from varying magnetic fields during the rocket flight, since the experiment procedures are very sensitive to external magnetic fields. A three-layer magnetic shielding provides a high shielding effectiveness factor of at least 1000 for an undisturbed operation of the experiment. The design of this magnetic shielding, the magnetic properties, simulations, and tests of its suitability for a sounding rocket flight are presented in this article.

  20. Laser-excited photoluminescence of three-layer GaAs double-heterostructure laser material

    International Nuclear Information System (INIS)

    Nash, F.R.; Dixon, R.W.; Barnes, P.A.; Schumaker, N.E.

    1975-01-01

    The successful fabrication of high-quality DH GaAs lasers from a simplified three-layer structure is reported. A major asset of this structure is the transparency of its final layer to recombination radiation occurring in the active layer, thus permitting the use of nondestructive photoluminescent techniques for material evaluation prior to device fabrication. In the course of photoluminescence investigations on this material the additional important observation has been made that indirect excitation (in which photocarriers are generated in the top ternary layer) has significant advantages over direct excitation (in which photocarriers are generated directly in the active layer). These include (i) the direct measurement of Al concentrations in both upper layers, (ii) the measurements of the minority-carrier diffusion length in the upper layer, (iii) an easily obtained indication of taper in the thickness of the upper layer, and (iv) surprisingly effective excitation of the active layer. By combining direct and indirect excitation it is shown that a clearer understanding of the location and detrimental influences of defects in the GaAs laser structure may be obtained. For example, the width of the region of reduced luminescence associated with many defects is found to be very excitation dependent and is confirmed to arise fr []m reduced active region luminescence. The photoluminescent excitation techniques described should be useful in the study of other heterostructure devices and material systems

  1. Application of a Three-Layer Photochemical Box Model in an Athens Street Canyon.

    Science.gov (United States)

    Proyou, Athena G; Ziomas, Loannis C; Stathopoulos, Antony

    1998-05-01

    The aim of this paper is to show that a photochemical box model could describe the air pollution diurnal profiles within a typical street canyon in the city of Athens. As sophisticated three-dimensional dispersion models are computationally expensive and they cannot serve to simulate pollution levels in the scale of an urban street canyon, a suitably modified three-layer photochemical box model was applied. A street canyon of Athens with heavy traffic was chosen to apply the aforementioned model. The model was used to calculate pollutant concentrations during two days with meteorological conditions favoring pollutant accumulation. Road traffic emissions were calculated based on existing traffic load measurements. Meteorological data, as well as various pollutant concentrations, in order to compare with the model results, were provided by available measurements. The calculated concentrations were found to be in good agreement with measured concentration levels and show that, when traffic load and traffic composition data are available, this model can be used to predict pollution episodes. It is noteworthy that high concentrations persisted, even after additional traffic restriction measures were taken on the second day because of the high pollution levels.

  2. Mechanical performance of SiC three-layer cladding in PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Angelici Avincola, Valentina, E-mail: valentina.avincola@kit.edu [Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Guenoun, Pierre, E-mail: pguenoun@mit.edu [Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); Shirvan, Koroush, E-mail: kshirvan@mit.edu [Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States)

    2016-12-15

    Highlights: • FEA calculations of the stress distribution in SiC three-layer cladding. • Simulation of SiC mechanical performance under operation and accident conditions. • Failure probability analysis of SiC in steady-state and accident conditions. - Abstract: The silicon carbide cladding concept is currently under investigation with regard to increasing the accident tolerance and economic performance of light-water reactor fuels. In this work, the stress fields in the multi-layered silicon carbide cladding for LWR fuels are calculated using the commercial finite element analysis software ADINA. The material properties under irradiation are implemented as a function of temperature. The cladding is studied under operating and accident conditions, specifically for the loss-of-coolant accident (LOCA). During the LOCA, the blowdown and the reflood phases are modeled, including the quench waterfront. The calculated stresses along the cladding thickness show a high sensitivity to the assumptions regarding material properties. The resulting stresses are compared with experimental data and the probability of failure is calculated considering a Weibull model.

  3. A three-layer magnetic shielding for the MAIUS-1 mission on a sounding rocket

    Energy Technology Data Exchange (ETDEWEB)

    Kubelka-Lange, André, E-mail: andre.kubelka@zarm.uni-bremen.de; Herrmann, Sven; Grosse, Jens; Lämmerzahl, Claus [Center of Applied Space Technology and Microgravity (ZARM), University of Bremen, Am Fallturm, 28359 Bremen (Germany); Rasel, Ernst M. [Institut für Quantenoptik, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover (Germany); Braxmaier, Claus [Center of Applied Space Technology and Microgravity (ZARM), University of Bremen, Am Fallturm, 28359 Bremen (Germany); DLR Institute for Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany)

    2016-06-15

    Bose-Einstein-Condensates (BECs) can be used as a very sensitive tool for experiments on fundamental questions in physics like testing the equivalence principle using matter wave interferometry. Since the sensitivity of these experiments in ground-based environments is limited by the available free fall time, the QUANTUS project started to perform BEC interferometry experiments in micro-gravity. After successful campaigns in the drop tower, the next step is a space-borne experiment. The MAIUS-mission will be an atom-optical experiment that will show the feasibility of experiments with ultra-cold quantum gases in microgravity in a sounding rocket. The experiment will create a BEC of 10{sup 5} {sup 87}Rb-atoms in less than 5 s and will demonstrate application of basic atom interferometer techniques over a flight time of 6 min. The hardware is specifically designed to match the requirements of a sounding rocket mission. Special attention is thereby spent on the appropriate magnetic shielding from varying magnetic fields during the rocket flight, since the experiment procedures are very sensitive to external magnetic fields. A three-layer magnetic shielding provides a high shielding effectiveness factor of at least 1000 for an undisturbed operation of the experiment. The design of this magnetic shielding, the magnetic properties, simulations, and tests of its suitability for a sounding rocket flight are presented in this article.

  4. Retrieval of Parameters for Three-Layer Media with Nonsmooth Interfaces for Subsurface Remote Sensing

    Directory of Open Access Journals (Sweden)

    Yuriy Goykhman

    2012-01-01

    Full Text Available A solution to the inverse problem for a three-layer medium with nonsmooth boundaries, representing a large class of natural subsurface structures, is developed in this paper using simulated radar data. The retrieval of the layered medium parameters is accomplished as a sequential nonlinear optimization starting from the top layer and progressively characterizing the layers below. The optimization process is achieved by an iterative technique built around the solution of the forward scattering problem. The forward scattering process is formulated by using the extended boundary condition method (EBCM and constructing reflection and transmission matrices for each interface. These matrices are then combined into the generalized scattering matrix for the entire system, from which radar scattering coefficients are then computed. To be efficiently utilized in the inverse problem, the forward scattering model is simulated over a wide range of unknowns to obtain a complete set of subspace-based equivalent closed-form models that relate radar backscattering coefficients to the sought-for parameters including dielectric constants of each layer and separation of the layers. The inversion algorithm is implemented as a modified conjugate-gradient-based nonlinear optimization. It is shown that this technique results in accurate retrieval of surface and subsurface parameters, even in the presence of noise.

  5. Technical assessment of three layered cement-bonded boards produced from wastepaper and sawdust

    International Nuclear Information System (INIS)

    Fuwape, Joseph Adeola; Fabiyi, James Sunday; Osuntuyi, Edward Olusola

    2007-01-01

    The technical properties of three layered cement-bonded boards (CBBs) made from wastepaper and sawdust were investigated. The CBBs were produced at three density levels of 1000, 1200 and 1300 kg/m 3 and at four cement/particle ratios of 2.0:1, 2.5:1, 3.0:1 and 3.5:1 on a weight to weight basis. The technical properties evaluated were modulus of rupture (MOR), modulus of elasticity (MOE), water absorption (WA) and thickness swelling (TS). The MOR values ranged from 4.85 to 11.69 MPa and MOE values ranged from 2.80 to 5.57 GPa. The mean values of WA and TS after 24 h of water soaking of the CBBs ranged from 18.18% to 40.49% and 3.55% to 12.13%, respectively. MOR and MOE of the CBBs increased with increase in board density, but MOR decreased with the increase in cement/particle ratio. On the other hand, WA and TS decreased with increase in board density and cement/particle ratio. CBBs produced from wastepaper and sawdust at cement/particle ratios of 3.0:1 and 3.5:1 are suitable for building construction such as paneling, ceiling and partitioning

  6. Molecular dynamics simulations of the three-layer hydrate of Na-montmorillonite

    International Nuclear Information System (INIS)

    Holmboe, Michael; Bourg, Ian C.

    2012-01-01

    the size of hundreds to tens or hundreds of thousands particles, MD simulations can be used to reveal how dynamic processes on the macro-scale (such as laboratory-scale values of the EA of diffusion), arise from the molecular scale. In order to obtain accurate and realistic transport properties of solutes in clays, such as self-diffusion coefficients, sorption behavior and EA of diffusion, one must probe realistic and physically relevant geochemical systems. Many previous studies using molecular simulation techniques studied relatively small smectite/water systems ( 4 atoms) using 'frozen' smectite clay layers, in order to save computational time, whereas the use of fully flexible clay layers has been advocated by several authors. In this study we present a sensitivity analysis of MD simulations of the three-layer hydrate of Na-montmorillonite. We focus in particular on the self-diffusion coefficients and their temperature-dependence, as well as structural data for the three-layer hydration state, which is expected to be the predominant hydration state in the bentonite barrier in different concepts of geological nuclear waste disposal, such as the Swedish KBS-3 concept. We also present a methodology for calculating the EA of diffusion for solutes in the interlayer nano-pores for temperatures 278 to 353 K, correcting for system size effects inherent to MD simulations as well as viscosity related effects for the SPC/E water model. In brief, our methodology uses the versatile MD code LAMMPS with a rigid SPC/E water model and the CLAYFF force field, which is known to satisfyingly predict structural and thermodynamical properties of smectite interlayer water and exchangeable cations. The CLAYFF force field describes the non-bonded atomic partial charges together with the van der Waals parameters of the clay structural atoms, which in this study is a typical 2:1 Na + -exchanged smectite (Wyoming montmorillonite) containing a negative structural charge of 0.66/unit cell

  7. Simulation of Natural Convection in the Oxide Layer of Three-Layer Corium Pool in an IVR

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su-Hyeon; Park, Hae-Kyun; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

    2016-10-15

    This paper describes the three-layer phenomena and preliminary plan to simulate the oxide layer experimentally. We will perform the mass transfer experiments using a copper sulfate-sulfuric acid (CuSO{sub 4}-H{sub 2}SO{sub 4}) electroplating system based on the heat and mass transfer analogy concept. By performing the mass transfer experiments, we can achieve the high buoyancy condition with small facilities. The test facility is semicircular whose bottom is chopped, simulating the oxide pool above the heavy metal layer in a three-layer configuration. We will measure the heat flux at the top plate, side wall and bottom plate, and compare these results with those for a two-layer pool. In a three-layer configuration, the upper light metal layer becomes thinner, increasing the focusing effect. Thus, it is important to evaluate the heat flux from the oxide pool to the upper metallic layer. However, there is few heat transfer studies for a three-layer configuration. This paper is to discuss and to make a plan for the heat transfer experiments of oxide pool in a three- layer system. We will perform the mass transfer experiments based on the heat and mass transfer analogy concept. The test results will be analyzed phenomenologically and compared with two-layer results.

  8. Neutron diffusion approximation solution for the the three layer borehole cylindrical geometry. Pt. 1. Theoretical description

    International Nuclear Information System (INIS)

    Czubek, J.A.; Woznicka, U.

    1997-01-01

    A solution of the neutron diffusion equation is given for a three layer cylindrical coaxial geometry. The calculation is performed in two neutron-energy groups which distinguish the thermal and epithermal neutron fluxes in the media irradiated by the fast point neutron source. The aim of the calculation is to define the neutron slowing down and migration lengths which are observed at a given point of the system. Generally, the slowing down and migration lengths are defined for an infinite homogenous medium (irradiated by the point neutron source) as a quotient of the neutron flux moment of the (2n + 2)-order to the moment of the 2n-order. Czubek(1992) introduced in the same manner the apparent neutron slowing down length and the apparent migration length for a given multi-region cylindrical geometry. The solutions in the present paper are applied to the method of semi-empirical calibration of neutron well-logging tools. The three-region cylindrical geometry corresponds to the borehole of radius R 1 surrounded by the intermediate region (e.g. mud cake) of thickness (R 2 -R 1 ) and finally surrounded by the geological formation which spreads from R 2 up to infinity. The cylinders of an infinite length are considered. The paper gives detailed solutions for the 0-th, 2-nd and 4-th neutron moments of the neutron fluxes for each neutron energy group and in each cylindrical layer. A comprehensive list of the solutions for integrals containing Bessel functions or their derivatives, which are absent in common tables of integrals, is also included. (author)

  9. Neutron diffusion approximation solution for the the three layer borehole cylindrical geometry. Pt. 1. Theoretical description

    Energy Technology Data Exchange (ETDEWEB)

    Czubek, J.A.; Woznicka, U. [The H. Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland)

    1997-12-31

    A solution of the neutron diffusion equation is given for a three layer cylindrical coaxial geometry. The calculation is performed in two neutron-energy groups which distinguish the thermal and epithermal neutron fluxes in the media irradiated by the fast point neutron source. The aim of the calculation is to define the neutron slowing down and migration lengths which are observed at a given point of the system. Generally, the slowing down and migration lengths are defined for an infinite homogenous medium (irradiated by the point neutron source) as a quotient of the neutron flux moment of the (2n{sup +}2)-order to the moment of the 2n-order. Czubek(1992) introduced in the same manner the apparent neutron slowing down length and the apparent migration length for a given multi-region cylindrical geometry. The solutions in the present paper are applied to the method of semi-empirical calibration of neutron well-logging tools. The three-region cylindrical geometry corresponds to the borehole of radius R{sub 1} surrounded by the intermediate region (e.g. mud cake) of thickness (R{sub 2}-R{sub 1}) and finally surrounded by the geological formation which spreads from R{sub 2} up to infinity. The cylinders of an infinite length are considered. The paper gives detailed solutions for the 0-th, 2-nd and 4-th neutron moments of the neutron fluxes for each neutron energy group and in each cylindrical layer. A comprehensive list of the solutions for integrals containing Bessel functions or their derivatives, which are absent in common tables of integrals, is also included. (author) 6 refs, 2 figs

  10. Thermal Rayleigh-Marangoni convection in a three-layer liquid-metal-battery model

    Science.gov (United States)

    Köllner, Thomas; Boeck, Thomas; Schumacher, Jörg

    2017-05-01

    The combined effects of buoyancy-driven Rayleigh-Bénard convection (RC) and surface tension-driven Marangoni convection (MC) are studied in a triple-layer configuration which serves as a simplified model for a liquid metal battery (LMB). The three-layer model consists of a liquid metal alloy cathode, a molten salt separation layer, and a liquid metal anode at the top. Convection is triggered by the temperature gradient between the hot electrolyte and the colder electrodes, which is a consequence of the release of resistive heat during operation. We present a linear stability analysis of the state of pure thermal conduction in combination with three-dimensional direct numerical simulations of the nonlinear turbulent evolution on the basis of a pseudospectral method. Five different modes of convection are identified in the configuration, which are partly coupled to each other: RC in the upper electrode, RC with internal heating in the molten salt layer, and MC at both interfaces between molten salt and electrode as well as anticonvection in the middle layer and lower electrode. The linear stability analysis confirms that the additional Marangoni effect in the present setup increases the growth rates of the linearly unstable modes, i.e., Marangoni and Rayleigh-Bénard instability act together in the molten salt layer. The critical Grashof and Marangoni numbers decrease with increasing middle layer thickness. The calculated thresholds for the onset of convection are found for realistic current densities of laboratory-sized LMBs. The global turbulent heat transfer follows scaling predictions for internally heated RC. The global turbulent momentum transfer is comparable with turbulent convection in the classical Rayleigh-Bénard case. In summary, our studies show that incorporating Marangoni effects generates smaller flow structures, alters the velocity magnitudes, and enhances the turbulent heat transfer across the triple-layer configuration.

  11. Excitation of magnetic inhomogeneities in three-layer ferromagnetic structure with different parameters of the magnetic anisotropy and exchange

    Energy Technology Data Exchange (ETDEWEB)

    Ekomasov, E.G., E-mail: EkomasovEG@gmail.com [Bashkir State University, 32, Validy Str., Ufa, 450076 (Russian Federation); Murtazin, R.R. [Bashkir State University, 32, Validy Str., Ufa, 450076 (Russian Federation); Nazarov, V.N. [Institute of Molecule and Crystal Physics Ufa Research Centre of Russian Academy of Sciences, Prospekt Oktyabrya 151, Ufa, 450075 (Russian Federation)

    2015-07-01

    The generation and evolution of magnetic inhomogeneities, emerging in a thin flat layer with the parameters of the magnetic anisotropy and exchange interaction, with the parameters different from other two thick layers of the three-layer ferromagnetic structure, were investigated. The parameters ranges that determine the possibility of their existence were found. The possibility of the external magnetic field influence on the structure and dynamic properties of localized magnetic inhomogeneities was shown. - Highlights: • The generation of magnetic inhomogeneities in the three-layer ferromagnetic. • The influence of an external field on the parameters of magnetic inhomogeneities. • Numerical study of the structure and dynamics of magnetic inhomogeneities.

  12. Three-layer GSO depth-of-interaction detector for high-energy gamma camera

    International Nuclear Information System (INIS)

    Yamamoto, S.; Watabe, H.; Kawachi, N.; Fujimaki, S.; Kato, K.; Hatazawa, J.

    2014-01-01

    Using Ce-doped Gd 2 SiO 5 (GSO) of different Ce concentrations, three-layer DOI block detectors were developed to reduce the parallax error at the edges of a pinhole gamma camera for high-energy gamma photons. GSOs with Ce concentrations of 1.5 mol% (decay time ∼40 ns), 0.5 mol% crystal (∼60 ns), 0.4 mol% (∼80 ns) were selected for the depth of interaction (DOI) detectors. These three types of GSOs were optically coupled in the depth direction, arranged in a 22×22 matrix and coupled to a flat panel photomultiplier tube (FP-PMT, Hamamatsu H8500). Sizes of these GSO cells were 1.9 mm×1.9 mm×4 mm, 1.9 mm×1.9 mm×5 mm, and 1.9 mm×1.9 mm×6 mm for 1.5 mol%, 0.5 mol%, and 0.4 mol%, respectively. With these combinations of GSOs, all spots corresponding to GSO cells were clearly resolved in the position histogram. Pulse shape spectra showed three peaks for these three decay times of GSOs. The block detector was contained in a 2-cm-thick tungsten shield, and a pinhole collimator with a 0.5-mm aperture was mounted. With pulse shape discrimination, we separated the point source images of the Cs-137 for each DOI layer. The point source image of the lower layer was detected at the most central part of the field-of-view, and the distribution was the smallest. The point source image of the higher layer was detected at the most peripheral part of the field-of-view, and the distribution was widest. With this information, the spatial resolution of the pinhole gamma camera can be improved. We conclude that DOI detection is effective for pinhole gamma cameras for high energy gamma photons

  13. Effective antireflection properties of porous silicon nanowires for photovoltaic applications

    KAUST Repository

    Najar, Adel

    2013-01-01

    Porous silicon nanowires (PSiNWs) have been prepared by metal-assisted chemical etching method on the n-Si substrate. The presence of nano-pores with pore size ranging between 10-50nm in SiNWs was confirmed by electron tomography (ET) in the transmission electron microscope (TEM). The PSiNWs give strong photoluminescence peak at red wavelength. Ultra-low reflectance of <5% span over wavelength 250 nm to 1050 nm has been measured. The finite-difference time-domain (FDTD) method has been employed to model the optical reflectance for both Si wafer and PSiNWs. Our calculation results are in agreement with the measured reflectance from nanowires length of 6 µm and 60% porosity. The low reflectance is attributed to the effective graded index of PSiNWs and enhancement of multiple optical scattering from the pores and nanowires. PSiNW structures with low surface reflectance can potentially serve as an antireflection layer for Si-based photovoltaic devices.

  14. Simple method for measuring reflectance of optical coatings

    International Nuclear Information System (INIS)

    Wen Gui Wang; Yi Sheng Chen

    1995-01-01

    The quality of optical coatings has an important effect on the performance of optical instrument. The last few years, the requirements for super low loss dielectric mirror coatings used in low gain laser systems such as free electron laser and the ring laser etc., have given an impetus to the development of the technology of precise reflectance measurement of optical coatings. A reliable and workable technique is to measure the light intensity decay time of optical resonant cavity. This paper describes a measuring method which is dependent on direct measurement of the light intensity decay time of a resonant cavity comprised of low loss optical components. According to the evolution of a luminous flux stored inside the cavity, this method guarantees not only a quick and precise reflectance measurements of low loss highly reflecting mirror coatings but also transmittance measurements of low loss antireflection coatings and is especially effective with super los loss highly reflecting mirror. From the round-trip path length of the cavity and the speed of light, the light intensity exponential decay time of an optical cavity is easy to obtain and the cavity losses can be deduced. An optical reflectance of low loss highly mirror coatings and antireflection coatings is precisely measured as well. This is highly significant for the discrimination of the coating surface characteristics, the improvement of the performance of optical instrument and the development of high technology

  15. Apparatus and method of manufacture for depositing a composite anti-reflection layer on a silicon surface

    Science.gov (United States)

    Pain, Bedabrata (Inventor)

    2012-01-01

    An apparatus and associated method are provided. A first silicon layer having at least one of an associated passivation layer and barrier is included. Also included is a composite anti-reflection layer including a stack of layers each with a different thickness and refractive index. Such composite anti-reflection layer is disposed adjacent to the first silicon layer.

  16. Fluorine Based Superhydrophobic Coatings

    Directory of Open Access Journals (Sweden)

    Jean-Denis Brassard

    2012-05-01

    Full Text Available Superhydrophobic coatings, inspired by nature, are an emerging technology. These water repellent coatings can be used as solutions for corrosion, biofouling and even water and air drag reduction applications. In this work, synthesis of monodispersive silica nanoparticles of ~120 nm diameter has been realized via Stöber process and further functionalized using fluoroalkylsilane (FAS-17 molecules to incorporate the fluorinated groups with the silica nanoparticles in an ethanolic solution. The synthesized fluorinated silica nanoparticles have been spin coated on flat aluminum alloy, silicon and glass substrates. Functionalization of silica nanoparticles with fluorinated groups has been confirmed by Fourier Transform Infrared spectroscopy (FTIR by showing the presence of C-F and Si-O-Si bonds. The water contact angles and surface roughness increase with the number of spin-coated thin films layers. The critical size of ~119 nm renders aluminum surface superhydrophobic with three layers of coating using as-prepared nanoparticle suspended solution. On the other hand, seven layers are required for a 50 vol.% diluted solution to achieve superhydrophobicity. In both the cases, water contact angles were more than 150°, contact angle hysteresis was less than 2° having a critical roughness value of ~0.700 µm. The fluorinated silica nanoparticle coated surfaces are also transparent and can be used as paint additives to obtain transparent coatings.

  17. THE CALCULATION OF STRESS-STRAIN STATE OF THREE-LAYER BEAM TAKING INTO ACCOUNT EDGE EFFECTS

    Directory of Open Access Journals (Sweden)

    Kh. M. Muselemov

    2015-01-01

    Full Text Available The work is dedicated to the calculation of the stress-strain state (SSS of the three-layer beam (TLB subject to boundary effects.In this paper, a system of differential equations of equilibrium of the threelayer beam. To solve these equations, it is necessary to know the 12 boundary conditions, co-which depend on support conditions and loading of sandwich beams under study. This system of equations is solved by the application package of mathematical modeling "Maple 5.4." The solution of this system we obtain expressions for determining de-formations and stress all components (bearing layers and filler, a three-layer beam anywhere under specified conditions of fastening the ends of the beam and its loading. 

  18. Design and fabrication of a nanostructured surface combining antireflective and enhanced-hydrophobic effects

    International Nuclear Information System (INIS)

    Chang, Y C; Mei, G H; Chang, T W; Wang, T J; Lin, D Z; Lee, C K

    2007-01-01

    Herein, we propose a special type of periodic subwavelength structure, which is optically an effective gradient-index (GRIN) antireflective surface that also exhibits enhanced-hydrophobic behaviour. Our new concept was developed adopting both the effective medium theory (EMT) and Wenzel's wettability model. To demonstrate the concept, an inverted pyramid structure was fabricated by electron beam (EB) lithography and anisotropic etching. The experimental data was found to be in good agreement with the theoretical prediction. Some potential applications that can benefit from this combination of antireflection and enhanced-hydrophobicity features are discussed

  19. Moth eye-inspired anti-reflective surfaces for improved IR optical systems & visible LEDs fabricated with colloidal lithography and etching.

    Science.gov (United States)

    Chan, Lesley W; Morse, Daniel E; Gordon, Michael J

    2018-05-08

    Near- and sub-wavelength photonic structures are used by numerous organisms (e.g. insects, cephalopods, fish, birds) to create vivid and often dynamically-tunable colors, as well as create, manipulate, or capture light for vision, communication, crypsis, photosynthesis, and defense. This review introduces the physics of moth eye (ME)-like, biomimetic nanostructures and discusses their application to reduce optical losses and improve efficiency of various optoelectronic devices, including photodetectors, photovoltaics, imagers, and light emitting diodes. Light-matter interactions at structured and heterogeneous surfaces over different length scales are discussed, as are the various methods used to create ME-inspired surfaces. Special interest is placed on a simple, scalable, and tunable method, namely colloidal lithography with plasma dry etching, to fabricate ME-inspired nanostructures in a vast suite of materials. Anti-reflective surfaces and coatings for IR devices and enhancing light extraction from visible light emitting diodes are highlighted.

  20. Design of multi-layer anti-reflection coating for terrestrial solar panel ...

    Indian Academy of Sciences (India)

    2National Centre for Photovoltaic Research & Education, Department of Electrical Engineering,. Indian Institute of Technology, Bombay 400 076, India ..... [6] Rancourt J D 1996 Optical thin films: user handbook (USA: McGraw-Hill Publications).

  1. Broad Bandwidth Metamaterial Antireflection Coatings for Measurement of the Cosmic Microwave Background

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cosmic Microwave Background (CMB) contains a number of faint signals that, if measured, could revolutionize our understandings of the Universe and fundamental...

  2. Layer-by-Layer-Assembled High-Performance Broadband Antireflection Coatings

    KAUST Repository

    Shimomura, Hiroomi; Gemici, Zekeriyya; Cohen, Robert E.; Rubner, Michael F.

    2010-01-01

    uniformity, thickness control, roughness control, mechanical durability, and incorporation of a diverse set of functional organic molecules into nanoparticle thin films are major challenges. We have used the electrostatic layer-by-layer assembly technique

  3. Indoor measurement of angle resolved light absorption by antireflective glass in solar panels

    DEFF Research Database (Denmark)

    Amdemeskel, Mekbib Wubishet; Benatto, Gisele Alves dos Reis; Riedel, Nicholas

    2017-01-01

    measurements with trackers. The experimental results showed optical responses that are stable and suitable for indoor characterization of solar cells. We find the characteristic optical response of six different antireflective glasses, and based on such measurements, we perform PVsyst simulations and present...

  4. A study of the anti-reflection efficiency of natural nano-arrays of varying sizes

    International Nuclear Information System (INIS)

    Sun Mingxia; Liang Aiping; Zheng Yongmei; Watson, Gregory S; Watson, Jolanta A

    2011-01-01

    The dependence of optical reflectivity and wettability on the surface topography of 32 species of cicada wing membranes has been investigated using UV-visible spectrophotometry, contact angle measurements and environmental scanning electron microscopy. The nanoscale hexagonally close packed protrusions have been shown to exhibit an anti-reflection and in some cases an anti-wetting function. The parameters of the structures were measured to be 77-148 nm in diameter, 44-117 nm in spacing and 159-481 nm in height. The transmittance spectrum and static contact angles were measured. At a wavelength range of 500-2500 nm, only minor differences in the anti-reflection performance were observed for each cicada species ascribed to the mechanism of impedance matching between cuticle and air. The transmittance properties of cicada wings were altered successfully through the scanning probe microscope-based manipulation by reducing the protrusion height via the contact mode. A near linear dependence was found between a decrease in protuberance height and a resulting increase in reflectance intensity. A diversity of wettability was observed with contact angles varying from 56.5 0 to 146.0 0 . Both effects of anti-reflection and wettability are dependent on the height of protrusions. The anti-reflection is insensitive when the wavelength is larger than the lateral feature size of the nanostructure. The stronger hydrophobic properties are generally associated with a larger diameter, closer spacing and greater height of protrusions when the wing membrane is intact.

  5. Minimizing scattering from antireflective surfaces replicated from low-aspect-ratio black silicon

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe; Mortensen, N. Asger

    2012-01-01

    The scattering properties of randomly structured antireflective black silicon polymer replica have been investigated. Using a two-step casting process, the structures can be replicated in Ormocomp on areas of up to 3 in. in diameter. Fourier analysis of scanning electron microscopy images...

  6. Omnidirectional luminescence enhancement of fluorescent SiC via pseudoperiodic antireflective subwavelength structures

    DEFF Research Database (Denmark)

    Ou, Yiyu; Jokubavicius, Valdas; Yakimova, Rositza

    2012-01-01

    In the present work, an approach of fabricating pseudoperiodic antireflective subwavelength structures (ARS) on fluorescent SiC by using self-assembled etch mask is demonstrated. By applying the pseudoperiodic (ARS), the average surface reflectance at 6° incidence over the spectral range of 390...

  7. Manufacturing and coating of optical components for the EnMAP hyperspectral imager

    Science.gov (United States)

    Schürmann, M.; Gäbler, D.; Schlegel, R.; Schwinde, S.; Peschel, T.; Damm, C.; Jende, R.; Kinast, J.; Müller, S.; Beier, M.; Risse, S.; Sang, B.; Glier, M.; Bittner, H.; Erhard, M.

    2016-07-01

    The optical system of the hyperspectral imager of the Environmental Mapping and Analysis Program (EnMAP) consists of a three-mirror anastigmat (TMA) and two independent spectrometers working in the VNIR and SWIR spectral range, respectively. The VNIR spectrometer includes a spherical NiP coated Al6061 mirror that has been ultra-precisely diamond turned and finally coated with protected silver as well as four curved fused silica (FS) and flint glass (SF6) prisms, respectively, each with broadband antireflection (AR) coating, while the backs of the two outer prisms are coated with a high-reflective coating. For AR coating, plasma ion assisted deposition (PIAD) has been used; the high-reflective enhanced Ag-coating on the backside has been deposited by magnetron sputtering. The SWIR spectrometer contains four plane and spherical gold-coated mirrors, respectively, and two curved FS prisms with a broadband antireflection coating. Details about the ultra-precise manufacturing of metal mirrors and prisms as well as their coating are presented in this work.

  8. Reduction of coating induced polarization aberrations by controlling the polarization state variation

    International Nuclear Information System (INIS)

    Li, Yanghui; Shen, Weidong; Zheng, Zhenrong; Zhang, Yueguang; Liu, Xu; Hao, Xiang

    2011-01-01

    The mechanism of coating induced polarization state variation is analysed by the Jones matrix. Pauli spin matrices are used to establish the relationship between coating induced polarization state variation and polarization aberrations. To reduce coating induced polarization aberrations, we propose that δ = 0 and T s = T p at arbitrary incident angle should be appended as two additional optimization goals of optical coating design when the requirements of transmittance are met. Two typical anti-reflection (AR) coatings are designed and the polarization state variation induced by them is simulated. The MTF (modulation transfer function) calculated by polarization ray tracing is applied to evaluate the polarization aberrations of the practical lithography objective system with the two AR coatings. All the obtained results show that the coating induced polarization aberrations can be reduced by optimizing the angle dependent properties of the optical coating without additional optical elements

  9. Y{sub 2}O{sub 3}: Eu{sup 3+}, Tb{sup 3+} spherical particles based anti-reflection and wavelength conversion bi-functional films: Synthesis and application to solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Hui [School of Physics, Northwest University, Xi’an 710069 (China); National Photoelectric Technology and Functional Materials & Application of Science and Technology International Cooperation Base, Northwest University, Xi’an 710069 (China); Ji, Ruonan [School of Physics, Northwest University, Xi’an 710069 (China); Hu, Xiaoyun, E-mail: hxy3275@nwu.edu.cn [School of Physics, Northwest University, Xi’an 710069 (China); National Photoelectric Technology and Functional Materials & Application of Science and Technology International Cooperation Base, Northwest University, Xi’an 710069 (China); Han, Linzi; Hao, Yuanyuan; Sun, Qian [School of Physics, Northwest University, Xi’an 710069 (China); Zhang, Dekai [School of Physics, Northwest University, Xi’an 710069 (China); National Photoelectric Technology and Functional Materials & Application of Science and Technology International Cooperation Base, Northwest University, Xi’an 710069 (China); Fan, Jun [School of Chemical Engineering, Northwest University, Xi’an 710069 (China); Bai, Jintao [School of Physics, Northwest University, Xi’an 710069 (China); National Photoelectric Technology and Functional Materials & Application of Science and Technology International Cooperation Base, Northwest University, Xi’an 710069 (China); and others

    2015-04-25

    Highlights: • Eu{sup 3+} and Tb{sup 3+} co-doped Y{sub 2}O{sub 3} particles were successfully prepared. The as prepared particles can convert UV region photos to visible photons between 460 nm and 640 nm, which just matched the spectral response of most solar cells. • Y{sub 2}O{sub 3} is not only a good photoluminescence host material, but also it has high corrosion resistivity, thermal stability, and transparency from violet to infrared light. Cooperated with SiO{sub 2} sols, it could realize a better anti-reflection property. • As a proof-of-concept application, the as prepared bi-functional films could effectively improve the photoelectric conversion efficiency by 0.23% compared to pure SiO{sub 2} AR coating film and 0.55% compared to glass. - Abstract: In this study, Eu{sup 3+} and Tb{sup 3+} co-doped Y{sub 2}O{sub 3} particles were prepared via the simple, cost-effective urea homogeneous precipitation method without additives. The chosen particles were added in the SiO{sub 2} sols to get anti-reflection (AR) and wavelength conversion bi-functional films. Careful investigations were carried out to find the optimum preparation conditions and proper morphology. SEM images showed that the particle sizes reduced as metal ion/urea ratio decreased. Additionally, the extracted particles turned from sphere to lamellar type when the deionized water, which was used as solvent, reduced to a certain extent. The mechanisms of the morphology formation and diversification were proposed as well. The as prepared materials can convert UV region photos to visible photons between 460 nm and 640 nm, which just matched the spectral response of most solar cells. The spherical sample showed better luminescence performance than the one with lamellar morphology. In addition, the optical transmittance spectra indicated that the films adding spherical particles had better anti-reflective performance, and the best adding amount was 0.08 g. Finally, As a proof-of-concept application

  10. Three-layered polyplex as a microRNA targeted delivery system for breast cancer gene therapy

    Science.gov (United States)

    Li, Yan; Dai, Yu; Zhang, Xiaojin; Chen, Jihua

    2017-07-01

    MicroRNAs (miRNAs), small non-coding RNAs, play an important role in modulating cell proliferation, migration, and differentiation. Since miRNAs can regulate multiple cancer-related genes simultaneously, regulating miRNAs could target a set of related oncogenic genes or pathways. Owing to their reduced immune response and low toxicity, miRNAs with small size and low molecular weight have become increasingly promising therapeutic drugs in cancer therapy. However, one of the major challenges of miRNAs-based cancer therapy is to achieve specific, effective, and safe delivery of therapeutic miRNAs into cancer cells. Here we provide a strategy using three-layered polyplex with folic acid as a targeting group to systemically deliver miR-210 into breast cancer cells, which results in breast cancer growth being inhibited.

  11. The DC field components of horizontal and vertical electric dipole sources immersed in three-layered stratified media

    Directory of Open Access Journals (Sweden)

    D. Llanwyn Jones

    Full Text Available Formulas for computing the Cartesian components of the static (DC fields of horizontal electric dipoles ( HEDs and vertical electric dipoles ( VEDs located in the central zone of a three-layer horizontally stratified medium are derived and presented in a summary form suitable for immediate computation. Formulas are given for the electric and magnetic field components in the upper and central regions. In the general case the computation involves the summation of a convergent infinite series. For the particular case of an infinitely thick central region (corresponding to the two-layer problem, the analysis produces relatively simple closed-form equations for the field components which are suitable for a 'hand calculation'. Specimen calculations for dipoles in seawaters are included and the derived results are compared with computations made using an ac model.

  12. The DC field components of horizontal and vertical electric dipole sources immersed in three-layered stratified media

    Directory of Open Access Journals (Sweden)

    D. Llanwyn Jones

    1997-04-01

    Full Text Available Formulas for computing the Cartesian components of the static (DC fields of horizontal electric dipoles ( HEDs and vertical electric dipoles ( VEDs located in the central zone of a three-layer horizontally stratified medium are derived and presented in a summary form suitable for immediate computation. Formulas are given for the electric and magnetic field components in the upper and central regions. In the general case the computation involves the summation of a convergent infinite series. For the particular case of an infinitely thick central region (corresponding to the two-layer problem, the analysis produces relatively simple closed-form equations for the field components which are suitable for a 'hand calculation'. Specimen calculations for dipoles in seawaters are included and the derived results are compared with computations made using an ac model.

  13. Three-layered architecture of the popliteal fascia that acts as a kinetic retinaculum for the hamstring muscles.

    Science.gov (United States)

    Satoh, Masahiro; Yoshino, Hiroyuki; Fujimura, Akira; Hitomi, Jiro; Isogai, Sumio

    2016-09-01

    When patients report pain in the popliteal fossa upon knee extension, the pain is usually localized in the lower region of the popliteal fossa. However, some patients complain of pain in the upper region of the popliteal fossa as the knee is flexed, which motivated us to examine the role of the popliteal fascia as the retinaculum of the hamstring muscles. Thirty-four thighs from 19 Japanese cadavers were dissected. The popliteal fascia was defined as the single aponeurotic sheet covering the popliteal fossa. We found that the fascia acted as a three-layered retinaculum for the flexor muscles of the thigh and provided a secure route for neurovascular structures to the lower leg in any kinetic position of the knee joint. The superficial layer of the popliteal fascia covering the thigh was strongly interwoven with the epimysium of biceps femoris along its lateral aspect and with that of the semimembranosus along its medial aspect, ensuring that the flexor muscles remained in their correct positions. The intermediate layer arose from the medial side of biceps femoris and merged medially with the superficial layer. The profound layer stretched transversely between the biceps femoris and the semimembranosus. Moreover, we investigated the nerve distribution in the popliteal fascia using Sihler's staining and whole-mount immunostaining for neurofilaments. The three-layered fascia was constantly innervated by branches from the posterior femoral cutaneous or saphenous nerve. The nerves were closely related and distributed to densely packed collagen fibers in the superficial layer as free or encapsulated nerve endings, suggesting that the fascia is involved in pain in the upper region of the popliteal fossa.

  14. Black metal thin films by deposition on dielectric antireflective moth-eye nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Caringal, Gideon Peter; Clausen, Jeppe Sandvik

    2015-01-01

    Although metals are commonly shiny and highly reflective, we here show that thin metal films appear black when deposited on a dielectric with antireflective moth-eye nanostructures. The nanostructures were tapered and close-packed, with heights in the range 300-600 nm, and a lateral, spatial...... frequency in the range 5-7 mu m(-1). A reflectance in the visible spectrum as low as 6%, and an absorbance of 90% was observed for an Al film of 100 nm thickness. Corresponding experiments on a planar film yielded 80% reflectance and 20% absorbance. The observed absorbance enhancement is attributed...... to a gradient effect causing the metal film to be antireflective, analogous to the mechanism in dielectrics and semiconductors. We find that the investigated nanostructures have too large spatial frequency to facilitate efficient coupling to the otherwise non-radiating surface plasmons. Applications...

  15. 3-D Printed Anti-Reflection Structures for the Terahertz Region

    Science.gov (United States)

    Bomba, Jarosław; Suszek, Jarosław; Makowski, Michał; Sobczyk, Artur; Sypek, Maciej

    2018-01-01

    Terahertz radiation has a growing number of applications in material characterization, where spectral fingerprinting and diffractive effects are the carriers of information. On the other hand, electromagnetic waves in the range of millimeters exhibit strong unwanted specular reflections, resulting in uncontrolled interferences. This problem is especially disturbing in the goniometric time-domain spectroscopy (TDS) configuration, where angular distribution of the field modified by the sample is altered by unwanted reflections. For this reason, low-cost anti-reflection layers are desired. Here, we present a simple way of designing and manufacturing one-sided and two-sided anti-reflection polyamide layers for the THz range. The structures were fabricated using 3-D printers based on selective laser sintering. We demonstrate experimentally in the goniometric time-domain spectroscopy the significant reduction of wavelength-dependent oscillations in Fabry-Perot configuration in the range between 0.1 and 0.3 THz. We also examine the influence of the anti-reflection layers on the distribution of THz energy in reflected, transmitted, and diffracted fields.

  16. Both antireflection and superhydrophobicity structures achieved by direct laser interference nanomanufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dapeng; Wang, Zuobin, E-mail: wangz@cust.edu.cn; Maple, Carsten [JR3CN and CNM, Changchun University of Science and Technology, Changchun, 130022 (China); JR3CN and IRAC, University of Bedfordshire, Luton, Bedfordshire LU1 3JU (United Kingdom); Zhang, Ziang [JR3CN and CNM, Changchun University of Science and Technology, Changchun, 130022 (China); Yue, Yong [JR3CN and CNM, Changchun University of Science and Technology, Changchun, 130022 (China); JR3CN and IRAC, University of Bedfordshire, Luton, Bedfordshire LU1 3JU (United Kingdom); DCSSE, Xi' an Jiaotong-Liverpool University, Suzhou, 215123 (China); Li, Dayou; Qiu, Renxi [JR3CN and IRAC, University of Bedfordshire, Luton, Bedfordshire LU1 3JU (United Kingdom)

    2014-06-21

    Inspired by nature, a number of techniques have been developed to fabricate the bionic structures of lotus leaves and moth eyes in order to realize the extraordinary functions of self-cleaning and antireflection. Compared with the existing technologies, we present a straightforward method to fabricate well-defined micro and nano artificial bio-structures in this work. The proposed method of direct laser interference nanomanufacturing (DLIN) takes a significant advantage of high efficiency as only a single technological procedure is needed without pretreatment, mask, and pattern transfer processes. Meanwhile, the corresponding structures show both antireflection and superhydrophobicity properties simultaneously. The developed four-beam nanosecond laser interference system configuring the TE-TE-TE-TE and TE-TE-TE-TM polarization modes was set up to generate periodic micro cone and hole structures with a huge number of nano features on the surface. The theoretical and experimental results have shown that the periodic microcone structure exhibits excellent properties with both a high contact angle (CA = 156.3°) and low omnidirectional reflectance (5.9–15.4%). Thus, DLIN is a novel and promising method suitable for mass production of self-cleaning and antireflection surface structures.

  17. Design principles for morphologies of antireflection patterns for solar absorbing applications.

    Science.gov (United States)

    Moon, Yoon-Jong; Na, Jin-Young; Kim, Sun-Kyung

    2015-07-01

    Two-dimensional surface texturing is a widespread technology for imparting broadband antireflection, yet its design rules are not completely understood. The dependence of the reflectance spectrum of a periodically patterned glass film on various structural parameters (e.g., pitch, height, shape, and fill factor) has been investigated by means of full-vectorial numerical simulations. An average weighted reflectivity accounting for the AM1.5G solar spectrum (λ=300-1000  nm) was sinusoidally modulated by a rod pattern's height, and was minimized for pitches of 400-600 nm. When a rationally optimized cone pattern was used, the average weighted reflectivity was less than 0.5%, for incident angles of up to 40° off normal. The broadband antireflection of a cone pattern was reproduced well by a graded refractive index film model corresponding to its geometry, with the addition of a diffraction effect resulting from its periodicity. The broadband antireflection ability of optimized cone patterns is not limited to the glass material, but rather is generically applicable to other semiconductor materials, including Si and GaAs. The design rules developed herein represent a key step in the development of light-absorbing devices, such as solar cells.

  18. Improved broadband and quasi-omnidirectional anti-reflection properties with biomimetic silicon nanostructures.

    Science.gov (United States)

    Huang, Yi-Fan; Chattopadhyay, Surojit; Jen, Yi-Jun; Peng, Cheng-Yu; Liu, Tze-An; Hsu, Yu-Kuei; Pan, Ci-Ling; Lo, Hung-Chun; Hsu, Chih-Hsun; Chang, Yuan-Huei; Lee, Chih-Shan; Chen, Kuei-Hsien; Chen, Li-Chyong

    2007-12-01

    Nature routinely produces nanostructured surfaces with useful properties, such as the self-cleaning lotus leaf, the colour of the butterfly wing, the photoreceptor in brittlestar and the anti-reflection observed in the moth eye. Scientists and engineers have been able to mimic some of these natural structures in the laboratory and in real-world applications. Here, we report a simple aperiodic array of silicon nanotips on a 6-inch wafer with a sub-wavelength structure that can suppress the reflection of light at a range of wavelengths from the ultraviolet, through the visible part of the spectrum, to the terahertz region. Reflection is suppressed for a wide range of angles of incidence and for both s- and p-polarized light. The antireflection properties of the silicon result from changes in the refractive index caused by variations in the height of the silicon nanotips, and can be simulated with models that have been used to explain the low reflection from moth eyes. The improved anti-reflection properties of the surfaces could have applications in renewable energy and electro-optical devices for the military.

  19. Surface Nanostructures Formed by Phase Separation of Metal Salt-Polymer Nanocomposite Film for Anti-reflection and Super-hydrophobic Applications

    Science.gov (United States)

    Con, Celal; Cui, Bo

    2017-12-01

    This paper describes a simple and low-cost fabrication method for multi-functional nanostructures with outstanding anti-reflective and super-hydrophobic properties. Our method employed phase separation of a metal salt-polymer nanocomposite film that leads to nanoisland formation after etching away the polymer matrix, and the metal salt island can then be utilized as a hard mask for dry etching the substrate or sublayer. Compared to many other methods for patterning metallic hard mask structures, such as the popular lift-off method, our approach involves only spin coating and thermal annealing, thus is more cost-efficient. Metal salts including aluminum nitrate nonahydrate (ANN) and chromium nitrate nonahydrate (CNN) can both be used, and high aspect ratio (1:30) and high-resolution (sub-50 nm) pillars etched into silicon can be achieved readily. With further control of the etching profile by adjusting the dry etching parameters, cone-like silicon structure with reflectivity in the visible region down to a remarkably low value of 2% was achieved. Lastly, by coating a hydrophobic surfactant layer, the pillar array demonstrated a super-hydrophobic property with an exceptionally high water contact angle of up to 165.7°.

  20. Ordered and disordered evolution of the pore mesostructure in hybrid silica anti-reflective films obtained by one-pot self-assembly method

    Energy Technology Data Exchange (ETDEWEB)

    Ghazzal, Mohamed N., E-mail: g_nawfel@yahoo.fr; Debecker, Damien P.; Gaigneaux, Eric M.

    2016-07-29

    Hybrid mesoporous silica films were prepared in acid-catalysed medium using a one-pot self-assembly method. A gradual content of methyl groups was introduced into the inorganic framework by co-condensation of tetraethyl orthosilicate and methyltriethoxysilane. To better understand how the ordered and disordered transition occurs in mesoporous hybrid organosilica sytem as function of the MTES molar ratio in the starting solution, textural, chemical and optical properties of the films were studied by transmission electronic microscopy (TEM), grazing-incident small angle X-ray scattering (GISAXS), transmission Fourier transformed infrared (FTIR) and UV–visible spectroscopy. Increasing the loading of the incorporated organic groups (up to 40% in the starting solution) led simultaneously to a disorganization of the pore mesostructure and a reduction in the pore diameter. Concomitantly, a disordered domain of the silica rings in the walls was observed, which created bond strains in the silica wall contributing also to the disorganization of the pore mesostructure. Furthermore, an optimal MTES content was identified in order to obtain antireflection coatings, exhibiting low reflection in the visible range. - Highlights: • Mesoporous hybrid silica films where prepared by one-pot co-condensation of MTES and TEOS. • Ordered and disordered mesostructures were studied as function as variable MTES molar ratio. • A rearrangement of the silica cyclic species occurred as the molar ratio of MTES increases. • Transmittance of the silica coatings is affected by the MTES molar ratio.

  1. Gradient Mn-La-Pt Catalysts with Three-layered Structure for Li-O2 battery

    Science.gov (United States)

    Cai, Kedi; Yang, Rui; Lang, Xiaoshi; Zhang, Qingguo; Wang, Zhenhua; He, Tieshi

    2016-01-01

    Gradient Mn-La-Pt catalysts with three-layered structure of manganese dioxide (MnO2), lanthanum oxide (La2O3), and Platinum (Pt) for Li-O2 battery are prepared in this study. The mass ratio of the catalysts is respectively 5:2:3, 4:2:4, and 3:2:5 (MnO2: La2O3: Pt) which is start from the side of the electrolyte. The relationship between morphology structure and electrochemical performance of gradient catalyst is investigated by energy dispersive spectrometry and constant current charge/discharge test. The Li-O2 battery based on gradient Mn-La-Pt catalysts shows high discharge specific capacity (2707 mAh g−1), specific energy density (8400 Wh kg−1) and long cycle life (56 cycles). The improvement of the Li-O2 battery discharge capacity is attributed to the gradient distribution of MnO2 and Pt and the involvement of La2O3 that can improve the energy density of the battery. More important, this work will also provide new ideas and methods for the research of other metal-air battery. PMID:27731340

  2. Thermal diffusivity measurements of molten salts using a three-layered cell by the laser flash method

    Science.gov (United States)

    Ohta, Hiromichi; Ogura, Gaku; Waseda, Yoshio; Suzuki, Mustumi

    1990-10-01

    A simple cell and easy data processing are described for measuring the thermal diffusivity of a liquid sample at high temperatures using the laser flash method. A cell consists of a liquid sample sandwiched by two metallic plates. The front surface of one metallic plate is exposed to a single pulse of beam laser and the resulting temperature rise of the back surface of the other metallic plate is measured. The logarithmic analysis proposed by James using the initial time region of the temperature response curve of a two layered cell system has been extended to apply to the present three layered cell system in order to estimate the thermal diffusivity value of a liquid sample. Measurements of distilled water and methanol were made first and the results were found to be in good agreement with the reference data. Then, the thermal diffusivities of molten NaNO3 at 593-660 K and of molten KNO3 at 621-694 K were determined and the results also appear to agree reasonably well with those reported in the literature.

  3. Interaction of a monopole vortex with an isolated topographic feature in a three-layer geophysical flow

    Directory of Open Access Journals (Sweden)

    E. A. Ryzhov

    2013-02-01

    Full Text Available In the frame of a three-layer, quasi-geostrophic analytical model of an f-plane geophysical flow, the Lagrangian advection induced by the interaction of a monopole vortex with an isolated topographic feature is addressed. Two different cases when the monopole is located either within the upper or the middle layer are of our interest. In the bottom layer, there is a delta-function topographic feature, which generates a closed recirculation region in its vicinity due to the background flow. This recirculation region extends to the middle and upper layers, and it plays the role of a topographic vortex. The interaction between the monopole and the topographic vortex causes a complex, including chaotic, advection of fluid particles. We show that the model's parameters, namely the monopole and topographic vortices' strengths and initial positions, and the layers' depths and densities, are responsible for the diverse advection patterns. While the patterns are rather complicated, one can single out two major processes, which mostly govern the fluid particle advection. The first one is the variation in time of the system's phase space structure, so that within the closed region of the topographic vortex, there appear periodically unclosed particle pathways by which the particles leave the topographic vortex. The second one is chaotic advection that arises from the nonstationarity of the monopole–topography interaction.

  4. Three-layered radio frequency coil arrangement for sodium MRI of the human brain at 9.4 Tesla.

    Science.gov (United States)

    Shajan, G; Mirkes, Christian; Buckenmaier, Kai; Hoffmann, Jens; Pohmann, Rolf; Scheffler, Klaus

    2016-02-01

    A multinuclei imaging setup with the capability to acquire both sodium ((23) Na) and proton ((1) H) signals at 9.4 Tesla is presented. The main objective was to optimize coil performance at the (23) Na frequency while still having the ability to acquire satisfactory (1) H images. The setup consisted of a combination of three radio frequency (RF) coils arranged in three layers: the innermost layer was a 27-channel (23) Na receive helmet which was surrounded by a four-channel (23) Na transceiver array. The outer layer consisted of a four-channel (1) H dipole array for B0 shimming and anatomical localization. Transmit and receive performance of the (23) Na arrays was compared to a single-tuned (23) Na birdcage resonator. While the transmit efficiency of the (23) Na transceiver array was comparable to the birdcage, the (23) Na receive array provided substantial signal-to-noise ratio (SNR) gain near the surface and comparable SNR in the center. The utility of this customized setup was demonstrated by (23) Na images of excellent quality. High SNR, efficient transmit excitation and B0 shimming capability can be achieved for (23) Na MRI at 9.4T using novel coil combination. This RF configuration is easily adaptable to other multinuclei applications at ultra high field (≥ 7T). © 2015 Wiley Periodicals, Inc.

  5. Nanoscale silver-assisted wet etching of crystalline silicon for anti-reflection surface textures.

    Science.gov (United States)

    Li, Rui; Wang, Shuling; Chuwongin, Santhad; Zhou, Weidong

    2013-01-01

    We report here an electro-less metal-assisted chemical etching (MacEtch) process as light management surface-texturing technique for single crystalline Si photovoltaics. Random Silver nanostructures were formed on top of the Si surface based on the thin film evaporation and annealing process. Significant reflection reduction was obtained from the fabricated Si sample, with approximately 2% reflection over a wide spectra range (300 to 1050 nm). The work demonstrates the potential of MacEtch process for anti-reflection surface texture fabrication of large area, high efficiency, and low cost thin film solar cell.

  6. Broadband antireflective silicon carbide surface produced by cost-effective method

    DEFF Research Database (Denmark)

    Argyraki, Aikaterini; Ou, Yiyu; Ou, Haiyan

    2013-01-01

    A cost-effective method for fabricating antireflective subwavelength structures on silicon carbide is demonstrated. The nanopatterning is performed in a 2-step process: aluminum deposition and reactive ion etching. The effect, of the deposited aluminum film thickness and the reactive ion etching...... conditions, on the average surface reflectance and nanostructure landscape have been investigated systematically. The average reflectance of silicon carbide surface is significantly suppressed from 25.4% to 0.05%, under the optimal experimental conditions, in the wavelength range of 390-784 nm. The presence...... of stochastic nanostructures also changes the wetting properties of silicon carbide surface from hydrophilic (47°) to hydrophobic (108°)....

  7. Sol-gel optical coatings for lasers: Part 1

    International Nuclear Information System (INIS)

    Floch, H.G.; Belleville, P.F.; Priotton, J.J.

    1995-01-01

    Many manufacturers and users claim that optical coatings are best prepared by physical vapor deposition technology. Others believe that sol-gel technology is an effective and competitive alternative. This article, the first of three, emphasizes sol-gel thin-film history and relates it to high-power laser technology, chemistry of the sol-gel process, production of optical coatings and deposition techniques. The second and third articles describe the preparation and performance of antireflective and highly reflective sol-gel optical coatings, respectively, that have been developed for the 1.8-MJ/500-TW (351-nm) pulsed neodymium-glass laser. This powerful laser is to be used in France's Inertial Confinement Fusion (ICF) program. It will demonstrate, at the laboratory scale, ignition of deuterium-tritium fusion fuel

  8. Microstructure and Mechanical Properties of Three-Layer TIG-Welded 2219 Aluminum Alloys with Dissimilar Heat Treatments

    Science.gov (United States)

    Zhang, Dengkui; Li, Quan; Zhao, Yue; Liu, Xianli; Song, Jianling; Wang, Guoqing; Wu, Aiping

    2018-05-01

    2219-C10S and 2219-CYS aluminum alloys are 2219 aluminum alloys with different heat treatment processes, and they have been widely used in the aerospace industry. In the present study, 2219-C10S and 2219-CYS aluminum alloys were butt-welded by three-layer tungsten inert gas arc welding (with the welding center of the third layer shifted toward the CYS side), and the microstructure characteristics and mechanical properties of the welded joint were investigated. The lamellar θ' phases, the bulk or rod θ phases, and the coarse rod-shaped or pancake-shaped Al-Cu-Fe-Mn phases coexisted in the two aluminum alloys. The Cu content of the α-Al matrix and the distribution of eutectic structures of different welding layers in the weld zone (WZ) were varied, implying that the segregation degrees of the Cu element were different due to the different welding thermal cycles in different welding layers. The microhardness values of the CYS side were much higher than those of the C10S side in each region on both sides of the joint. The tensile test deformation was concentrated mainly in the regions of WZ and the over aged zone (OAZ), where the microhardness values were relatively low. The main deformation concentrated region was transferred from the CYS side to the C10S side with the increase in the tensile load during the tensile test. The fracture behavior of the tensile test showed that the macroscopic crack initiated near the front weld toe had gone through the crack blunt region, the shear fracture region of the partially melted zone (PMZ), and the shear fracture region of OAZ. Meanwhile, the fracture characteristics gradually evolved from brittle to ductile. The concentrated stress and the dense eutectic structure in the region near the front weld toe of the C10S side contributed to the fracture of the joint. The shift of the welding center of the third layer to the CYS side resulted in two effects: (i) the microhardness values from the middle layer to the top layer in the

  9. High temperature solar selective coatings

    Science.gov (United States)

    Kennedy, Cheryl E

    2014-11-25

    Improved solar collectors (40) comprising glass tubing (42) attached to bellows (44) by airtight seals (56) enclose solar absorber tubes (50) inside an annular evacuated space (54. The exterior surfaces of the solar absorber tubes (50) are coated with improved solar selective coatings {48} which provide higher absorbance, lower emittance and resistance to atmospheric oxidation at elevated temperatures. The coatings are multilayered structures comprising solar absorbent layers (26) applied to the meta surface of the absorber tubes (50), typically stainless steel, topped with antireflective Savers (28) comprising at least two layers 30, 32) of refractory metal or metalloid oxides (such as titania and silica) with substantially differing indices of refraction in adjacent layers. Optionally, at least one layer of a noble metal such as platinum can be included between some of the layers. The absorbent layers cars include cermet materials comprising particles of metal compounds is a matrix, which can contain oxides of refractory metals or metalloids such as silicon. Reflective layers within the coating layers can comprise refractory metal silicides and related compounds characterized by the formulas TiSi. Ti.sub.3SiC.sub.2, TiAlSi, TiAN and similar compounds for Zr and Hf. The titania can be characterized by the formulas TiO.sub.2, Ti.sub.3O.sub.5. TiOx or TiO.sub.xN.sub.1-x with x 0 to 1. The silica can be at least one of SiO.sub.2, SiO.sub.2x or SiO.sub.2xN.sub.1-x with x=0 to 1.

  10. Variation in the Optical Properties of the SiC-SiO2 Composite Antireflection Layer in Crystalline Silicon Solar Cells by Annealing

    Science.gov (United States)

    Jannat, Azmira; Li, Zhen Yu; Akhter, M. Shaheer; Yang, O.-Bong

    2017-11-01

    This study showed the effects of annealing on a sol-gel-derived SiC-SiO2 composite antireflection (AR) layer and investigated the optical and photovoltaic properties of crystalline silicon (Si) solar cells. The SiC-SiO2 composite AR coating showed a considerable decrease in reflectance from 7.18% to 3.23% at varying annealing temperatures of 450-800°C. The refractive indices of the SiC-SiO2 composite AR layer were tuned from 2.06 to 2.45 with the increase in annealing temperature. The analysis of the current density-voltage characteristics indicated that the energy conversion efficiencies of the fabricated Si solar cells gradually increased from 16.99% to 17.73% with increasing annealing temperatures of 450-800°C. The annealing of the SiC-SiO2 composite AR layer in Si solar cells was crucial to improving the optical, morphological, and photovoltaic properties.

  11. 3D-Printed Broadband Dielectric Tube Terahertz Waveguide with Anti-Reflection Structure

    Science.gov (United States)

    Vogt, Dominik Walter; Leonhardt, Rainer

    2016-11-01

    We demonstrate broadband, low loss, and close-to-zero dispersion guidance of terahertz (THz) radiation in a dielectric tube with an anti-reflection structure (AR-tube waveguide) in the frequency range from 0.2 to 1.0 THz. The anti-reflection structure (ARS) consists of close-packed cones in a hexagonal lattice arranged on the outer surface of the tube cladding. The feature size of the ARS is in the order of the wavelength between 0.2 and 1.0 THz. The waveguides are fabricated with the versatile and cost efficient 3D-printing method. Terahertz time-domain spectroscopy (THz-TDS) measurements as well as 3D finite-difference time-domain simulations (FDTD) are performed to extensively characterize the AR-tube waveguides. Spectrograms, attenuation spectra, effective phase refractive indices, and the group-velocity dispersion parameters β 2 of the AR-tube waveguides are presented. Both the experimental and numerical results confirm the extended bandwidth and smaller group-velocity dispersion of the AR-tube waveguide compared to a low loss plain dielectric tube THz waveguide. The AR-tube waveguide prototypes show an attenuation spectrum close to the theoretical limit given by the infinite cladding tube waveguide.

  12. Deep and tapered silicon photonic crystals for achieving anti-reflection and enhanced absorption.

    Science.gov (United States)

    Hung, Yung-Jr; Lee, San-Liang; Coldren, Larry A

    2010-03-29

    Tapered silicon photonic crystals (PhCs) with smooth sidewalls are realized using a novel single-step deep reactive ion etching. The PhCs can significantly reduce the surface reflection over the wavelength range between the ultra-violet and near-infrared regions. From the measurements using a spectrophotometer and an angle-variable spectroscopic ellipsometer, the sub-wavelength periodic structure can provide a broad and angular-independent antireflective window in the visible region for the TE-polarized light. The PhCs with tapered rods can further reduce the reflection due to a gradually changed effective index. On the other hand, strong optical resonances for TM-mode can be found in this structure, which is mainly due to the existence of full photonic bandgaps inside the material. Such resonance can enhance the optical absorption inside the silicon PhCs due to its increased optical paths. With the help of both antireflective and absorption-enhanced characteristics in this structure, the PhCs can be used for various applications.

  13. Fabrication of antireflective nanostructures for crystalline silicon solar cells by reactive ion etching

    International Nuclear Information System (INIS)

    Lin, Hsin-Han; Chen, Wen-Hua; Wang, Chi-Jen; Hong, Franklin Chau-Nan

    2013-01-01

    In this study we have fabricated large-area (15 × 15 cm 2 ) subwavelength antireflection structure on poly-Si substrates to reduce their solar reflectivity. A reactive ion etching system was used to fabricate nanostructures on the poly-silicon surface. Reactive gases, composed of chlorine (Cl 2 ), sulfur hexafluoride (SF 6 ) and oxygen (O 2 ), were activated to fabricate nanoscale pyramids by RF plasma. The poly-Si substrates were etched in various gas compositions for 6–10 min to form nano-pyramids. The sizes of pyramids were about 200–300 nm in heights and about 100 nm in width. Besides the nanoscale features, the high pyramid density on the poly-Si surface is another important factor to reduce the reflectivity. Low-reflectivity surface was fabricated with reflectivity significantly reduced down to < 2% for photons in a wavelength range of 500–900 nm. - Highlights: ► Large-area (15 × 15 cm 2 ) antireflection structures fabricated on poly-Si substrates ► Si nano-pyramids produced by utilizing self-masked reactive ion etching process ► High density of nanoscale pyramids was formed on the entire substrate surface. ► Surface reflectivity below 2% was achieved in the wavelength range of 500–900 nm

  14. Selectively coated high efficiency glazing for solar-thermal flat-plate collectors

    International Nuclear Information System (INIS)

    Ehrmann, N.; Reineke-Koch, R.

    2012-01-01

    In order to increase the efficiency of solar-thermal flat-plate collectors at temperatures above 100 °C or with low solar irradiation, we implement a double glazing with a low-emitting (low-e) coating on the inner pane to improve the insulation of the transparent cover. Since commercially available low-e glazing provides only insufficient solar transmittance for the application in thermal flat-plate collectors we are developing a sputter-deposited low e-coating system based on transparent conductive oxides which provides a high solar transmittance of 85% due to additional antireflective coatings and the use of low-iron glass substrates. Durability tests of the developed coating system show that our low e-coating system is well suitable even at high temperatures, humidity and condensation.

  15. High-power optical coatings for a mega-joule class ICF laser

    International Nuclear Information System (INIS)

    Kozlowski, M.R.; Thomas, I.M.; Campbell, J.H.; Rainer, F.

    1992-11-01

    As a consequence of advancements in Inertial Confinement Fusion research, LLNL is developing plans for a new 1.5 to 2 mega-joule solid-state Nd:glass laser designed to achieve fusion ignition. The new design is possible in part due to advances in optical coatings suitable for high power laser systems. High damage threshold mirrors and polarizers are comprised of electron beam deposited dielectric multilayers. Subthreshold illumination, or laser conditioning, of the multilayer coatings results in an increase in the damage thresholds by factors of 2 to 3 at 1.06μm, thus meeting the fluence requirements of the advanced architecture. For anti-reflective coatings, protective organic coatings for non-linear crystals and phase plates for beam smoothing, sol-gel films provide high damage thresholds coatings at low cost

  16. Experimental evaluation of coating delamination in vinyl coated metal forming

    International Nuclear Information System (INIS)

    Son, Young Ki; Lee, Chan Joo; Kim, Byung Min; Lee, Jung Min; Byoen, Sang Doek; Lee, Soen Bong

    2012-01-01

    In this paper, a new evaluation and prediction method for coating delamination during sheet metal forming is presented. On the basis of the forming limit diagram (FLD), the current study evaluates the delamination of PET coating by using a cross cut specimen, dome test, and rectangular cup drawing test. Dome test specimens were subjected to biaxial, plane strain, and uniaxial deformation modes. Rectangular cup drawing test specimens were subjected to the deep drawing deformation mode, and compression deformation mode. A vinyl coated metal (VCM) sheet consists of three layers of polymer on the sheet metals: a protective film, a PET layer and a PVC layer. The areas with coating delamination were identified, and the results of the evaluation were plotted according to major and minor strain values, depicting coating delamination. The constructed delamination limit diagram (DLD) can be used to determine the forming limit of VCM during the complex press forming process. ARGUS (GOM) was employed to identify the strain value and deformation mode of the delaminated surface after the press forming. After identifying the areas of delamination, the DLD of the PET coating can be constructed in a format similar to that of the FLD. The forming limit of the VCM sheet can be evaluated using the superimposition of the delamination limit strain of the coating onto the FLD of VCM sheet. The experimental results showed that the proposed test method will support the sheet metal forming process design for VCM sheets. The assessment method presented in this study can be used to determine the delamination limit strain under plastic deformation of other polymer coated metals. The experimental results suggested that the proposed testing method is effective in evaluating delamination for specific applications

  17. Experimental evaluation of coating delamination in vinyl coated metal forming

    Energy Technology Data Exchange (ETDEWEB)

    Son, Young Ki; Lee, Chan Joo; Kim, Byung Min [Pusan National Univ., Busan (Korea, Republic of); Lee, Jung Min [Korea Institute of Industrial Technology, Busan (Korea, Republic of); Byoen, Sang Doek [HA Digital Engineering Gr., Seongsan Gu (Korea, Republic of); Lee, Soen Bong [Keimyung Univ., Daegu (Korea, Republic of)

    2012-10-15

    In this paper, a new evaluation and prediction method for coating delamination during sheet metal forming is presented. On the basis of the forming limit diagram (FLD), the current study evaluates the delamination of PET coating by using a cross cut specimen, dome test, and rectangular cup drawing test. Dome test specimens were subjected to biaxial, plane strain, and uniaxial deformation modes. Rectangular cup drawing test specimens were subjected to the deep drawing deformation mode, and compression deformation mode. A vinyl coated metal (VCM) sheet consists of three layers of polymer on the sheet metals: a protective film, a PET layer and a PVC layer. The areas with coating delamination were identified, and the results of the evaluation were plotted according to major and minor strain values, depicting coating delamination. The constructed delamination limit diagram (DLD) can be used to determine the forming limit of VCM during the complex press forming process. ARGUS (GOM) was employed to identify the strain value and deformation mode of the delaminated surface after the press forming. After identifying the areas of delamination, the DLD of the PET coating can be constructed in a format similar to that of the FLD. The forming limit of the VCM sheet can be evaluated using the superimposition of the delamination limit strain of the coating onto the FLD of VCM sheet. The experimental results showed that the proposed test method will support the sheet metal forming process design for VCM sheets. The assessment method presented in this study can be used to determine the delamination limit strain under plastic deformation of other polymer coated metals. The experimental results suggested that the proposed testing method is effective in evaluating delamination for specific applications.

  18. One-step Maskless Fabrication and Optical Characterization of Silicon Surfaces with Antireflective Properties and a White Color Appearance

    DEFF Research Database (Denmark)

    Sun, Ling; Feidenhans'l, Nikolaj Agentoft; Telecka, Agnieszka

    2016-01-01

    We report a simple one-step maskless fabrication of inverted pyramids on silicon wafers by reactive ion etching. The fabricated surface structures exhibit excellent anti-reflective properties: The total reflectance of the nano inverted pyramids fabricated by our method can be as low as 12% withou...... milky white color....

  19. Corrosion Resistance Of Electroless Ni-P/Cu/Ni-P Multilayer Coatings

    Directory of Open Access Journals (Sweden)

    Zhao G.L.

    2015-06-01

    Full Text Available Ni-P/Cu/Ni-P multilayer coatings were prepared by deposition of Cu layer between two Ni–P layers. The Cu layer was deposited by metal displacement reaction between Cu2+ and Fe atoms. Corrosion behavior of single-layer Ni-P coatings, double-layer Ni-P/Cu coatings, and three-layer Ni-P/Cu/Ni-P coatings were investigated by electrochemical tests in 3.5% NaCl solution. The three-layer coatings exhibited more positive Ecorr and decreased Icorr compared with conventional single-layer Ni-P coatings, which indicated an improved corrosion resistance. The polarization curves of the three-layer coatings were characterized by two passive regions. The improved corrosion resistance was not only attributed to the function of the blocked pores of Cu. The Cu interlayer also acted as a sacrificial layer instead of a barrier in the coatings, which altered the corrosion mechanism and further improved the corrosion resistance of the coatings.

  20. On the roto-translatory internal motions of a three layer non-isobarycentric Earth model: a Lagrangian system approach

    Science.gov (United States)

    Escapa, Alberto; Fukushima, Toshio

    2010-05-01

    The internal structure of numerous celestial bodies are well approximated by means of a three layer model composed of a solid external layer, which encloses a fluid layer containing a solid body. An analysis of the inner dynamics of this model can provide some constrains on its rheological characteristics; an information that in many situations is only accessible through this indirect way. In addition, the understanding of this kind of motions, especially of those associated with a rigid displacement (a rotation or a relative translation) of the solid layers, is of primary importance to establish with enough accuracy the definition of the terrestrial reference frames. In the Earth case, most approaches to this formidable problem rely on the numerical solution of the respective elastic field equations, once they have been projected on a set of spherical harmonics functions of a given degree. Due to its intrinsic nature these numerical methods do not provide by themselves much insight into the internal dynamics, hence the interest to develop simpler dynamical models that reproduces the main characteristics of the motion and allows obtaining analytical approximate solutions of the problem. To this aim, and as a first stage, we have considered the internal dynamics of a simple Earth model made up of a spherical rigid mantle, an inviscid, homogeneous fluid outer core and a spherical rigid inner core. Initially the barycenters of all the constituents are located at the same point (isobarycentric model) and the whole system rotates with constant angular velocity around the figure axis. When this situation is perturbed both the motions of the fluid and of the solid layers depart from the reference uniform rotation. However, following Busse (1974) we have assumed that the motion of the mantle is the same as in the unperturbed state, and that the inner core dynamics only suffers a variation of oscillatory nature in the translational motion of its barycenter. As a consequence

  1. Model-based analysis of nonstationary thermal mode in premises with an insolation passive heating system with a three-layer translucent shield

    International Nuclear Information System (INIS)

    Avezova, N.R.; Avezov, R.R.; Rashidov, Y.K. et al.

    2014-01-01

    The results of the model-based study of nonstationary thermal mode in premises with an insolation passive heating system with a three-layer translucent shield are presented. The article is aimed at determining daily variations in the air temperature of the heated premise on typical heating season days and analyzing the optimization of the thermal capacity of the short-term (daily) thermal battery of the heating system on this basis. (author)

  2. Invited Article: Narrowband terahertz bandpass filters employing stacked bilayer metasurface antireflection structures

    Science.gov (United States)

    Chang, Chun-Chieh; Huang, Li; Nogan, John; Chen, Hou-Tong

    2018-05-01

    We experimentally demonstrate high-performance narrowband terahertz (THz) bandpass filters through cascading multiple bilayer metasurface antireflection structures. Each bilayer metasurface, consisting of a square array of silicon pillars with a self-aligned top gold resonator-array and a complementary bottom gold slot-array, enables near-zero reflection and simultaneously close-to-unity single-band transmission at designed operational frequencies in the THz spectral region. The THz bandpass filters based on stacked bilayer metasurfaces allow a fairly narrow, high-transmission passband, and a fast roll-off to an extremely clean background outside the passband, thereby providing superior bandpass performance. The demonstrated scheme of narrowband THz bandpass filtering is of great importance for a variety of applications where spectrally clean, high THz transmission over a narrow bandwidth is desired, such as THz spectroscopy and imaging, molecular detection and monitoring, security screening, and THz wireless communications.

  3. Scalable Production of Mechanically Robust Antireflection Film for Omnidirectional Enhanced Flexible Thin Film Solar Cells.

    Science.gov (United States)

    Wang, Min; Ma, Pengsha; Yin, Min; Lu, Linfeng; Lin, Yinyue; Chen, Xiaoyuan; Jia, Wei; Cao, Xinmin; Chang, Paichun; Li, Dongdong

    2017-09-01

    Antireflection (AR) at the interface between the air and incident window material is paramount to boost the performance of photovoltaic devices. 3D nanostructures have attracted tremendous interest to reduce reflection, while the structure is vulnerable to the harsh outdoor environment. Thus the AR film with improved mechanical property is desirable in an industrial application. Herein, a scalable production of flexible AR films is proposed with microsized structures by roll-to-roll imprinting process, which possesses hydrophobic property and much improved robustness. The AR films can be potentially used for a wide range of photovoltaic devices whether based on rigid or flexible substrates. As a demonstration, the AR films are integrated with commercial Si-based triple-junction thin film solar cells. The AR film works as an effective tool to control the light travel path and utilize the light inward more efficiently by exciting hybrid optical modes, which results in a broadband and omnidirectional enhanced performance.

  4. High quality antireflective ZnS thin films prepared by chemical bath deposition

    International Nuclear Information System (INIS)

    Tec-Yam, S.; Rojas, J.; Rejón, V.; Oliva, A.I.

    2012-01-01

    Zinc sulfide (ZnS) thin films for antireflective applications were deposited on glass substrates by chemical bath deposition (CBD). Chemical analysis of the soluble species permits to predict the optimal pH conditions to obtain high quality ZnS films. For the CBD, the ZnCl 2 , NH 4 NO 3 , and CS(NH 2 ) 2 were fixed components, whereas the KOH concentration was varied from 0.8 to 1.4 M. Groups of samples with deposition times from 60 to 120 min were prepared in a bath with magnetic agitation and heated at 90 °C. ZnS films obtained from optimal KOH concentrations of 0.9 M and 1.0 M exhibited high transparency, homogeneity, adherence, and crystalline. The ZnS films presented a band gap energy of 3.84 eV, an atomic Zn:S stoichiometry ratio of 49:51, a transmittance above 85% in the 300–800 nm wavelength range, and a reflectance below 25% in the UV–Vis range. X-ray diffraction analysis revealed a cubic structure in the (111) orientation for the films. The thickness of the films was tuned between 60 nm and 135 nm by controlling the deposition time and KOH concentration. The incorporation of the CBD-ZnS films into ITO/ZnS/CdS/CdTe and glass/Mo/ZnS heterostructures as antireflective layer confirms their high optical quality. -- Highlights: ► High quality ZnS thin films were prepared by chemical bath deposition (CBD). ► Better CBD-ZnS films were achieved by using 0.9 M-KOH concentration. ► Reduction in the reflectance was obtained for ZnS films used as buffer layers.

  5. Laser-damage thresholds of thin-film optical coatings at 248 nm

    International Nuclear Information System (INIS)

    Milam, D.; Rainer, F.; Lowdermilk, W.H.

    1981-01-01

    We have measured the laser-induced damage thresholds for 248 nm wavelength light of over 100 optical coatings from commercial vendors and research institutions. All samples were irradiated once per damage site with temporally multi-lobed, 20-ns pulses generated by a KrF laser. The survey included high, partial, and dichroic reflectors, anti-reflective coatings, and single layer films. The samples were supplied by ten vendors. The majority of samples tested were high reflectors and antireflective coatings. The highest damage thresholds were 8.5 to 9.4 J/cm 2 , respectively. Although these represent extremes of what has been tested so far, several vendors have produced coatings of both types with thresholds which consistently exceed 6 J/cm 2 . Repeated irradiations of some sites were made on a few samples. These yielded no degradation in threshold, but in fact some improvement in damage resistance. These same samples also exhibited no change in threshold after being retested seven months later

  6. Design of functional hybrid coatings with anti-biofouling, self-cleaning and anti-reflecting applications

    OpenAIRE

    Santiago Sánchez, Alexander

    2016-01-01

    263 p. Los recubrimientos son aplicados sobre diferentes superficies con fines fundamentalmente decorativos y de protección. Sin embargo, hoy en día el mercado de estos materiales está siendo sometido a unas especificaciones cada vez más severas. Así, los recubrimientos actuales deben, además de ser decorativos y protectores del sustrato, impartir al mismo otras propiedades adicionales como por ejemplo baja adherencia a los microorganismos, facilidad de limpieza y propiedades auto-reparabl...

  7. Fabrication of highly transparent diamond-like carbon anti-reflecting coating for Si solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Amit, E-mail: erdd@iacs.res.in; Das, Debajyoti, E-mail: erdd@iacs.res.in [Nano-Science Group, Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700032 (India)

    2014-04-24

    ARC grade highly transparent unhydrogenated diamond-like carbon (DLC) films were produced, directly from a-C target, using RF magnetron sputtering deposition technique, for optoelectronic applications. Optical band gap, transmittance, reflectance, sp{sup 3} fraction, I{sub D}/I{sub G}, density, and refractive index of the films have been estimated with the help of optical tools like Uv-vis spectrophotometer, ellipsometer and micro-Raman. Optimum ARC-qualities have been identified in low-temperature grown DLC films at an Ar pressure of 4 mTorr in the reactor, accomplishing its key requirements for use in silicon solar cells.

  8. Silicon nitride and intrinsic amorphous silicon double antireflection coatings for thin-film solar cells on foreign substrates

    International Nuclear Information System (INIS)

    Li, Da; Kunz, Thomas; Wolf, Nadine; Liebig, Jan Philipp; Wittmann, Stephan; Ahmad, Taimoor; Hessmann, Maik T.; Auer, Richard; Göken, Mathias; Brabec, Christoph J.

    2015-01-01

    Hydrogenated intrinsic amorphous silicon (a-Si:H) was investigated as a surface passivation method for crystalline silicon thin film solar cells on graphite substrates. The results of the experiments, including quantum efficiency and current density-voltage measurements, show improvements in cell performance. This improvement is due to surface passivation by an a-Si:H(i) layer, which increases the open circuit voltage and the fill factor. In comparison with our previous work, we have achieved an increase of 0.6% absolute cell efficiency for a 40 μm thick 4 cm 2 aperture area on the graphite substrate. The optical properties of the SiN x /a-Si:H(i) stack were studied using spectroscopic ellipsometer techniques. Scanning transmission electron microscopy inside a scanning electron microscope was applied to characterize the cross section of the SiN x /a-Si:H(i) stack using focus ion beam preparation. - Highlights: • We report a 10.8% efficiency for thin-film silicon solar cell on graphite. • Hydrogenated intrinsic amorphous silicon was applied for surface passivation. • SiN x /a-Si:H(i) stacks were characterized by spectroscopic ellipsometer techniques. • Cross-section micrograph was obtained by scanning transmission electron microscopy. • Quantum efficiency and J-V measurements show improvements in the cell performance

  9. The fusion of dt{mu}, tt{mu} and dd{mu} molecules in three-layer arrangement including deuterium degrader and moderator

    Energy Technology Data Exchange (ETDEWEB)

    Gheisari, R. [Physics Department, Persian Gulf University, Bushehr 75169 (Iran)

    2010-09-15

    Muon dynamics and forced chemical confinement fusion in three-layer arrangement consisting of the H/T, D{sub 2} (the degrader and moderator) and D/T fusion layers are investigated with a new kinetic model. Point kinematic equations are numerically solved to calculate the numbers of dt{mu}, tt{mu} and dd{mu} chain reactions. We show that the {mu}-cycling coefficient X{sub c} approximately equals 156, at optimal condition. Our model and results are in contradiction with beliefs of Mahdavi and Zanganeh. Our model is confirmed by recent experiment where was performed for the hydrogen mixture. (author)

  10. Bioactivity of calcium phosphate bioceramic coating fabricated by laser cladding

    Science.gov (United States)

    Zhu, Yizhi; Liu, Qibin; Xu, Peng; Li, Long; Jiang, Haibing; Bai, Yang

    2016-05-01

    There were always strong expectations for suitable biomaterials used for bone regeneration. In this study, to improve the biocompatiblity of titanium alloy, calcium phosphate bioceramic coating was obtained by laser cladding technology. The microstructure, phases, bioactivity, cell differentiation, morphology and resorption lacunae were investigated by optical microscope (OM), x-ray diffraction (XRD), methyl thiazolyl tetrazolium (MTT) assay, tartrate-resistant acid phosphatase (TRAP) staining and scanning electronic microscope (SEM), respectively. The results show that bioceramic coating consists of three layers, which are a substrate, an alloyed layer and a ceramic layer. Bioactive phases of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) were found in ceramic coating. Osteoclast precursors have excellent proliferation on the bioceramic surface. The bioceramics coating could be digested by osteoclasts, which led to the resorption lacunae formed on its surface. It revealed that the gradient bioceramic coating has an excellent bioactivity.

  11. Bioactivity of calcium phosphate bioceramic coating fabricated by laser cladding

    International Nuclear Information System (INIS)

    Zhu, Yizhi; Liu, Qibin; Xu, Peng; Li, Long; Jiang, Haibing; Bai, Yang

    2016-01-01

    There were always strong expectations for suitable biomaterials used for bone regeneration. In this study, to improve the biocompatiblity of titanium alloy, calcium phosphate bioceramic coating was obtained by laser cladding technology. The microstructure, phases, bioactivity, cell differentiation, morphology and resorption lacunae were investigated by optical microscope (OM), x-ray diffraction (XRD), methyl thiazolyl tetrazolium (MTT) assay, tartrate-resistant acid phosphatase (TRAP) staining and scanning electronic microscope (SEM), respectively. The results show that bioceramic coating consists of three layers, which are a substrate, an alloyed layer and a ceramic layer. Bioactive phases of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) were found in ceramic coating. Osteoclast precursors have excellent proliferation on the bioceramic surface. The bioceramics coating could be digested by osteoclasts, which led to the resorption lacunae formed on its surface. It revealed that the gradient bioceramic coating has an excellent bioactivity. (letter)

  12. Study of microstructure and superconducting properties of Nb3Al-tapes, obtained by heat treatment of three-layer and multilayer composites Nb/AlCu

    International Nuclear Information System (INIS)

    Korzhov, Valeriy P.

    2012-01-01

    The structure and superconductivity of three- and multilayer composite tapes of Nb/AlCu after high- temperature heating at 1750-1850 0 C for 1-3 seconds were investigated. Three-layer composites of Nb/AlCu/Nb with thickness of 50 microns were obtained by applying a vacuum rolling at 400-450 0 C and subsequent rolling at room temperature. Multilayer lengthy composites of Nb/AlCu obtained by extrusion with subsequent flattening by rolling of complex blank, collected in a special way. The effect of copper on the structure and properties of three-layer tapes was investigated. Copper increased the critical current of the superconductor. The critical current density in multilayered Nb 3 Al-tape reaches the value 8.10 4 A/cm 2 in magnetic field 14 T. The critical bending radius of the tape is 7 mm. Key words: multilayer composite tape, extrusion, rolling, superconducting Nb 3 Al-tape, high- temperature heat treatment, critical current density

  13. Three-layer microfibrous peripheral nerve guide conduit composed of elastin-laminin mimetic artificial protein and poly(L-lactic acid

    Directory of Open Access Journals (Sweden)

    Sachiro eKakinoki

    2014-07-01

    Full Text Available We developed a microfibrous poly(L-lactic acid (PLLA nerve conduit with a three-layered structure to simultaneously enhance nerve regeneration and prevent adhesion of surrounding tissue. The inner layer was composed of PLLA microfiber containing 25% elastin-laminin mimetic protein (AG73-(VPGIG30 that promotes neurite outgrowth. The thickest middle layer was constructed of pure PLLA microfibers that impart the large mechanical stremgth to the conduit. A 10% poly(ethylene glycol was added to the outer layer to prevent the adhesion with the surrounding tissue. The AG73-(VPGIG30 composisting of an elastin-like repetitive sequence (VPGIG30 and a laminin-derived sequence (RKRLQVQLSIRT: AG73 was biosynthesized using Escherichia coli. The PLLA microfibrous conduits were fabricated using an electrospinning procedure. AG73-(VPGIG30 was successfully mixed in the PLLA microfibers, and the PLLA/AG73-(VPGIG30 microfibers were stable under physiological conditions. The PLLA/AG73-(VPGIG30 microfibers enhanced adhesion and neurite outgrowth of PC12 cells. The electrospun microfibrous conduit with a three-layered structure was implanted for bridging a 2.0-cm gap in the tibial nerve of a rabbit. Two months after implantation, no adhesion of surrounding tissue was observed, and the action potential was slightly improved in the nerve conduit with the PLLA/AG73-(VPGIG30 inner layer.

  14. Three-layer microfibrous peripheral nerve guide conduit composed of elastin-laminin mimetic artificial protein and poly(L-lactic acid)

    Science.gov (United States)

    Kakinoki, Sachiro; Nakayama, Midori; Moritan, Toshiyuki; Yamaoka, Tetsuji

    2014-07-01

    We developed a microfibrous poly(L-lactic acid) (PLLA) nerve conduit with a three-layered structure to simultaneously enhance nerve regeneration and prevent adhesion of surrounding tissue. The inner layer was composed of PLLA microfiber containing 25% elastin-laminin mimetic protein (AG73-(VPGIG)30) that promotes neurite outgrowth. The thickest middle layer was constructed of pure PLLA microfibers that impart the large mechanical stremgth to the conduit. A 10% poly(ethylene glycol) was added to the outer layer to prevent the adhesion with the surrounding tissue. The AG73-(VPGIG)30 composisting of an elastin-like repetitive sequence (VPGIG)30 and a laminin-derived sequence (RKRLQVQLSIRT: AG73) was biosynthesized using Escherichia coli. The PLLA microfibrous conduits were fabricated using an electrospinning procedure. AG73-(VPGIG)30 was successfully mixed in the PLLA microfibers, and the PLLA/AG73-(VPGIG)30 microfibers were stable under physiological conditions. The PLLA/AG73-(VPGIG)30 microfibers enhanced adhesion and neurite outgrowth of PC12 cells. The electrospun microfibrous conduit with a three-layered structure was implanted for bridging a 2.0-cm gap in the tibial nerve of a rabbit. Two months after implantation, no adhesion of surrounding tissue was observed, and the action potential was slightly improved in the nerve conduit with the PLLA/AG73-(VPGIG)30 inner layer.

  15. A high-sensitivity fiber-optic evanescent wave sensor with a three-layer structure composed of Canada balsam doped with GeO2.

    Science.gov (United States)

    Zhong, Nianbing; Zhao, Mingfu; Zhong, Lianchao; Liao, Qiang; Zhu, Xun; Luo, Binbin; Li, Yishan

    2016-11-15

    In this paper, we present a high-sensitivity polymer fiber-optic evanescent wave (FOEW) sensor with a three-layer structure that includes bottom, inter-, and surface layers in the sensing region. The bottom layer and inter-layer are POFs composed of standard cladding and the core of the plastic optical fiber, and the surface layer is made of dilute Canada balsam in xylene doped with GeO2. We examine the morphology of the doped GeO2, the refractive index and composition of the surface layer and the surface luminous properties of the sensing region. We investigate the effects of the content and morphology of the GeO2 particles on the sensitivity of the FOEW sensors by using glucose solutions. In addition, we examine the response of sensors incubated with staphylococcal protein A plus mouse IgG isotype to goat anti-mouse IgG solutions. Results indicate very good sensitivity of the three-layer FOEW sensor, which showed a 3.91-fold improvement in the detection of the target antibody relative to a conventional sensor with a core-cladding structure, and the novel sensor showed a lower limit of detection of 0.2ng/l and a response time around 320s. The application of this high-sensitivity FOEW sensor can be extended to biodefense, disease diagnosis, biomedical and biochemical analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Characterization and properties of an advanced composite substrate for YBCO-coated conductors

    DEFF Research Database (Denmark)

    Gao, M.; Suo, H.; Zhao, Y.

    2010-01-01

    Thin, biaxially textured Ni5W/Ni12W/Ni5W composite substrates for coated conductor applications have been fabricated. The particularity of this three-layer composite configuration resides in the elemental diffusion between the outer layer and the core layer. Due to the migration of elemental W...

  17. Motorcycle helmets: What about their coating?

    Science.gov (United States)

    Schnegg, Michaël; Massonnet, Geneviève; Gueissaz, Line

    2015-07-01

    In traffic accidents involving motorcycles, paint traces can be transferred from the rider's helmet or smeared onto its surface. These traces are usually in the form of chips or smears and are frequently collected for comparison purposes. This research investigates the physical and chemical characteristics of the coatings found on motorcycles helmets. An evaluation of the similarities between helmet and automotive coating systems was also performed.Twenty-seven helmet coatings from 15 different brands and 22 models were considered. One sample per helmet was collected and observed using optical microscopy. FTIR spectroscopy was then used and seven replicate measurements per layer were carried out to study the variability of each coating system (intravariability). Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were also performed on the infrared spectra of the clearcoats and basecoats of the data set. The most common systems were composed of two or three layers, consistently involving a clearcoat and basecoat. The coating systems of helmets with composite shells systematically contained a minimum of three layers. FTIR spectroscopy results showed that acrylic urethane and alkyd urethane were the most frequent binders used for clearcoats and basecoats. A high proportion of the coatings were differentiated (more than 95%) based on microscopic examinations. The chemical and physical characteristics of the coatings allowed the differentiation of all but one pair of helmets of the same brand, model and color. Chemometrics (PCA and HCA) corroborated classification based on visual comparisons of the spectra and allowed the study of the whole data set at once (i.e., all spectra of the same layer). Thus, the intravariability of each helmet and its proximity to the others (intervariability) could be more readily assessed. It was also possible to determine the most discriminative chemical variables based on the study of the PCA loadings. Chemometrics

  18. Topological characterization of antireflective and hydrophobic rough surfaces: are random process theory and fractal modeling applicable?

    Science.gov (United States)

    Borri, Claudia; Paggi, Marco

    2015-02-01

    The random process theory (RPT) has been widely applied to predict the joint probability distribution functions (PDFs) of asperity heights and curvatures of rough surfaces. A check of the predictions of RPT against the actual statistics of numerically generated random fractal surfaces and of real rough surfaces has been only partially undertaken. The present experimental and numerical study provides a deep critical comparison on this matter, providing some insight into the capabilities and limitations in applying RPT and fractal modeling to antireflective and hydrophobic rough surfaces, two important types of textured surfaces. A multi-resolution experimental campaign using a confocal profilometer with different lenses is carried out and a comprehensive software for the statistical description of rough surfaces is developed. It is found that the topology of the analyzed textured surfaces cannot be fully described according to RPT and fractal modeling. The following complexities emerge: (i) the presence of cut-offs or bi-fractality in the power-law power-spectral density (PSD) functions; (ii) a more pronounced shift of the PSD by changing resolution as compared to what was expected from fractal modeling; (iii) inaccuracy of the RPT in describing the joint PDFs of asperity heights and curvatures of textured surfaces; (iv) lack of resolution-invariance of joint PDFs of textured surfaces in case of special surface treatments, not accounted for by fractal modeling.

  19. Calculation of femtosecond pulse laser induced damage threshold for broadband antireflective microstructure arrays.

    Science.gov (United States)

    Jing, Xufeng; Shao, Jianda; Zhang, Junchao; Jin, Yunxia; He, Hongbo; Fan, Zhengxiu

    2009-12-21

    In order to more exactly predict femtosecond pulse laser induced damage threshold, an accurate theoretical model taking into account photoionization, avalanche ionization and decay of electrons is proposed by comparing respectively several combined ionization models with the published experimental measurements. In addition, the transmittance property and the near-field distribution of the 'moth eye' broadband antireflective microstructure directly patterned into the substrate material as a function of the surface structure period and groove depth are performed by a rigorous Fourier model method. It is found that the near-field distribution is strongly dependent on the periodicity of surface structure for TE polarization, but for TM wave it is insensitive to the period. What's more, the femtosecond pulse laser damage threshold of the surface microstructure on the pulse duration taking into account the local maximum electric field enhancement was calculated using the proposed relatively accurate theoretical ionization model. For the longer incident wavelength of 1064 nm, the weak linear damage threshold on the pulse duration is shown, but there is a surprising oscillation peak of breakdown threshold as a function of the pulse duration for the shorter incident wavelength of 532 nm.

  20. Design and Preparation of a Micro-Pyramid Structured Thin Film for Broadband Infrared Antireflection

    Directory of Open Access Journals (Sweden)

    Shaobo Ge

    2018-05-01

    Full Text Available A micro-pyramid structured thin film with a broad-band infrared antireflection property is designed and fabricated by using the single-point diamond turning (SPDT technique and combined with nano-imprint lithography (NIL. A structure with dimensions of 10 μm pitch and 5 μm height is transferred from the copper mold to the silicon nitride optical film by using NIL and proportional inductively-coupled plasma (ICP etching. Reflectance of the micro-optical surface is reduced below 1.0% over the infrared spectral range (800–2500 nm. A finite-difference-time-domain (FDTD analysis indicates that this micro-structure can localize photons and enhance the absorption inside the micro-pyramid at long wavelengths. As described above, the micro-pyramid array has been integrated in an optical film successfully. Distinguishing from the traditional micro-optical components, considering the effect of refraction and diffraction, it is a valuable and flexible method to take account of the interference effect of optical film.

  1. Multifunctional porous silicon nanopillar arrays: antireflection, superhydrophobicity, photoluminescence, and surface-enhanced Raman scattering

    International Nuclear Information System (INIS)

    Kiraly, Brian; Yang, Shikuan; Huang, Tony Jun

    2013-01-01

    We have fabricated porous silicon nanopillar arrays over large areas with a rapid, simple, and low-cost technique. The porous silicon nanopillars show unique longitudinal features along their entire length and have porosity with dimensions on the single-nanometer scale. Both Raman spectroscopy and photoluminescence data were used to determine the nanocrystallite size to be <3 nm. The porous silicon nanopillar arrays also maintained excellent ensemble properties, reducing reflection nearly fivefold from planar silicon in the visible range without any optimization, and approaching superhydrophobic behavior with increasing aspect ratio, demonstrating contact angles up to 138°. Finally, the porous silicon nanopillar arrays were made into sensitive surface-enhanced Raman scattering (SERS) substrates by depositing metal onto the pillars. The SERS performance of the substrates was demonstrated using a chemical dye Rhodamine 6G. With their multitude of properties (i.e., antireflection, superhydrophobicity, photoluminescence, and sensitive SERS), the porous silicon nanopillar arrays described here can be valuable in applications such as solar harvesting, electrochemical cells, self-cleaning devices, and dynamic biological monitoring. (paper)

  2. Plasma-Induced, Self-Masking, One-Step Approach to an Ultrabroadband Antireflective and Superhydrophilic Subwavelength Nanostructured Fused Silica Surface.

    Science.gov (United States)

    Ye, Xin; Shao, Ting; Sun, Laixi; Wu, Jingjun; Wang, Fengrui; He, Junhui; Jiang, Xiaodong; Wu, Wei-Dong; Zheng, Wanguo

    2018-04-25

    In this work, antireflective and superhydrophilic subwavelength nanostructured fused silica surfaces have been created by one-step, self-masking reactive ion etching (RIE). Bare fused silica substrates with no mask were placed in a RIE vacuum chamber, and then nanoscale fluorocarbon masks and subwavelength nanostructures (SWSs) automatically formed on these substrate after the appropriate RIE plasma process. The mechanism of plasma-induced self-masking SWS has been proposed in this paper. Plasma parameter effects on the morphology of SWS have been investigated to achieve perfect nanocone-like SWS for excellent antireflection, including process time, reactive gas, and pressure of the chamber. Optical properties, i.e., antireflection and optical scattering, were simulated by the finite difference time domain (FDTD) method. Calculated data agree well with the experiment results. The optimized SWS show ultrabroadband antireflective property (up to 99% from 500 to 1360 nm). An excellent improvement of transmission was achieved for the deep-ultraviolet (DUV) range. The proposed low-cost, highly efficient, and maskless method was applied to achieve ultrabroadband antireflective and superhydrophilic SWSs on a 100 mm optical window, which promises great potential for applications in the automotive industry, goggles, and optical devices.

  3. Stable Single-Mode Operation of Distributed Feedback Quantum Cascade Laser by Optimized Reflectivity Facet Coatings

    Science.gov (United States)

    Wang, Dong-Bo; Zhang, Jin-Chuan; Cheng, Feng-Min; Zhao, Yue; Zhuo, Ning; Zhai, Shen-Qiang; Wang, Li-Jun; Liu, Jun-Qi; Liu, Shu-Man; Liu, Feng-Qi; Wang, Zhan-Guo

    2018-02-01

    In this work, quantum cascade lasers (QCLs) based on strain compensation combined with two-phonon resonance design are presented. Distributed feedback (DFB) laser emitting at 4.76 μm was fabricated through a standard buried first-order grating and buried heterostructure (BH) processing. Stable single-mode emission is achieved under all injection currents and temperature conditions without any mode hop by the optimized antireflection (AR) coating on the front facet. The AR coating consists of a double layer dielectric of Al2O3 and Ge. For a 2-mm laser cavity, the maximum output power of the AR-coated DFB-QCL was more than 170 mW at 20 °C with a high wall-plug efficiency (WPE) of 4.7% in a continuous-wave (CW) mode.

  4. Development of beryllium-based neutron target system with three-layer structure for accelerator-based neutron source for boron neutron capture therapy.

    Science.gov (United States)

    Kumada, Hiroaki; Kurihara, Toshikazu; Yoshioka, Masakazu; Kobayashi, Hitoshi; Matsumoto, Hiroshi; Sugano, Tomei; Sakurai, Hideyuki; Sakae, Takeji; Matsumura, Akira

    2015-12-01

    The iBNCT project team with University of Tsukuba is developing an accelerator-based neutron source. Regarding neutron target material, our project has applied beryllium. To deal with large heat load and blistering of the target system, we developed a three-layer structure for the target system that includes a blistering mitigation material between the beryllium used as the neutron generator and the copper heat sink. The three materials were bonded through diffusion bonding using a hot isostatic pressing method. Based on several verifications, our project chose palladium as the intermediate layer. A prototype of the neutron target system was produced. We will verify that sufficient neutrons for BNCT treatment are generated by the device in the near future. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. A two-in-one superhydrophobic and anti-reflective nanodevice in the grey cicada Cicada orni (Hemiptera)

    Energy Technology Data Exchange (ETDEWEB)

    Dellieu, Louis, E-mail: louis.dellieu@unamur.be; Sarrazin, Michaël, E-mail: michael.sarrazin@unamur.be; Simonis, Priscilla; Deparis, Olivier; Vigneron, Jean Pol [Research Center in Physics of Matter and Radiation (PMR), Department of Physics, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur (Belgium)

    2014-07-14

    Two separated levels of functionality are identified in the nanostructure which covers the wings of the grey cicada Cicada orni (Hemiptera). The upper level is responsible for superhydrophobic character of the wing, while the lower level enhances its anti-reflective behavior. Extensive wetting experiments with various chemical species and optical measurements were performed in order to assess the bi-functionality. Scanning electron microscopy imaging was used to identify the nanostructure morphology. Numerical optical simulations and analytical wetting models were used to prove the roles of both levels of the nanostructure. In addition, the complex refractive index of the chitinous material of the wing was determined from measurements.

  6. A two-in-one superhydrophobic and anti-reflective nanodevice in the grey cicada Cicada orni (Hemiptera)

    Science.gov (United States)

    Dellieu, Louis; Sarrazin, Michaël; Simonis, Priscilla; Deparis, Olivier; Vigneron, Jean Pol

    2014-07-01

    Two separated levels of functionality are identified in the nanostructure which covers the wings of the grey cicada Cicada orni (Hemiptera). The upper level is responsible for superhydrophobic character of the wing, while the lower level enhances its anti-reflective behavior. Extensive wetting experiments with various chemical species and optical measurements were performed in order to assess the bi-functionality. Scanning electron microscopy imaging was used to identify the nanostructure morphology. Numerical optical simulations and analytical wetting models were used to prove the roles of both levels of the nanostructure. In addition, the complex refractive index of the chitinous material of the wing was determined from measurements.

  7. A two-in-one superhydrophobic and anti-reflective nanodevice in the grey cicada Cicada orni (Hemiptera)

    International Nuclear Information System (INIS)

    Dellieu, Louis; Sarrazin, Michaël; Simonis, Priscilla; Deparis, Olivier; Vigneron, Jean Pol

    2014-01-01

    Two separated levels of functionality are identified in the nanostructure which covers the wings of the grey cicada Cicada orni (Hemiptera). The upper level is responsible for superhydrophobic character of the wing, while the lower level enhances its anti-reflective behavior. Extensive wetting experiments with various chemical species and optical measurements were performed in order to assess the bi-functionality. Scanning electron microscopy imaging was used to identify the nanostructure morphology. Numerical optical simulations and analytical wetting models were used to prove the roles of both levels of the nanostructure. In addition, the complex refractive index of the chitinous material of the wing was determined from measurements.

  8. Porous Nanomaterials for Ultrabroadband Omnidirectional Anti-Reflection Surfaces with Applications in High Concentration Photovoltaics

    KAUST Repository

    Yao, Yuan; Lee, Kyu Tae; Sheng, Xing; Batara, Nicolas A.; Hong, Nina; He, Junwen; Xu, Lu; Hussain, Muhammad Mustafa; Atwater, Harry A.; Lewis, Nathan S.; Nuzzo, Ralph G.; Rogers, John A.

    2016-01-01

    Materials for nanoporous coatings that exploit optimized chemistries and self-assembly processes offer capabilities to reach ≈98% transmission efficiency and negligible scattering losses over the broad wavelength range of the solar spectrum from 350

  9. Nanoscale imaging of photocurrent enhancement by resonator array photovoltaic coatings

    Science.gov (United States)

    Ha, Dongheon; Yoon, Yohan; Zhitenev, Nikolai B.

    2018-04-01

    Nanoscale surface patterning commonly used to increase absorption of solar cells can adversely impact the open-circuit voltage due to increased surface area and recombination. Here, we demonstrate absorptivity and photocurrent enhancement using silicon dioxide (SiO2) nanosphere arrays on a gallium arsenide (GaAs) solar cell that do not require direct surface patterning. Due to the combined effects of thin-film interference and whispering gallery-like resonances within nanosphere arrays, there is more than 20% enhancement in both absorptivity and photocurrent. To determine the effect of the resonance coupling between nanospheres, we perform a scanning photocurrent microscopy based on a near-field scanning optical microscopy measurement and find a substantial local photocurrent enhancement. The nanosphere-based antireflection coating (ARC), made by the Meyer rod rolling technique, is a scalable and a room-temperature process; and, can replace the conventional thin-film-based ARCs requiring expensive high-temperature vacuum deposition.

  10. Antireflective conducting nanostructures with an atomic layer deposited an AlZnO layer on a transparent substrate

    International Nuclear Information System (INIS)

    Park, Hyun-Woo; Ji, Seungmuk; Herdini, Diptya Suci; Lim, Hyuneui; Park, Jin-Seong; Chung, Kwun-Bum

    2015-01-01

    Graphical abstract: - Highlights: • We investigated the antireflective conducting nanostructures on a transparent substrate using atomic layer deposited AlZnO films. • The conformal AlZnO layer on a transparent nanostructured substrate exhibited 5.52 × 10 −4 Ω cm in resistivity and 88% in average visible transmittance. • The improvement of transparency was explained by the gradual changes of the refractive index in the film depth direction. • The decrease in electrical resistivity is strongly correlated to the increased surface area with the nanostructure and the change of chemical bonding states. - Abstract: The antireflective conducting nanostructures on a transparent substrate were shown to have enhanced optical and electrical properties via colloidal lithography and atomic layer deposition. The conformal AlZnO layer on a transparent nanostructured substrate exhibited 5.52 × 10 −4 Ω cm in resistivity and 88% in average visible transmittance, both of which were superior to those of a flat transparent conducting substrate. The improvement of transparency was explained by the gradual changes of the refractive index in the film depth direction. The decrease in electrical resistivity is strongly correlated to the increased surface area with the nanostructure and the change of chemical bonding states.

  11. Hard coatings

    International Nuclear Information System (INIS)

    Dan, J.P.; Boving, H.J.; Hintermann, H.E.

    1993-01-01

    Hard, wear resistant and low friction coatings are presently produced on a world-wide basis, by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, CVD and PVD. Some of the most advanced processes, especially those dedicated to thin film depositions, basically belong to CVD or PVD technologies, and will be looked at in more detail. The hard coatings mainly consist of oxides, nitrides, carbides, borides or carbon. Over the years, many processes have been developed which are variations and/or combinations of the basic CVD and PVD methods. The main difference between these two families of deposition techniques is that the CVD is an elevated temperature process (≥ 700 C), while the PVD on the contrary, is rather a low temperature process (≤ 500 C); this of course influences the choice of substrates and properties of the coating/substrate systems. Fundamental aspects of the vapor phase deposition techniques and some of their influences on coating properties will be discussed, as well as the very important interactions between deposit and substrate: diffusions, internal stress, etc. Advantages and limitations of CVD and PVD respectively will briefly be reviewed and examples of applications of the layers will be given. Parallel to the development and permanent updating of surface modification technologies, an effort was made to create novel characterisation methods. A close look will be given to the coating adherence control by means of the scratch test, at the coating hardness measurement by means of nanoindentation, at the coating wear resistance by means of a pin-on-disc tribometer, and at the surface quality evaluation by Atomic Force Microscopy (AFM). Finally, main important trends will be highlighted. (orig.)

  12. A three-layer model of self-assembly induced surface-energy variation experimentally extracted by using nanomechanically sensitive cantilevers

    International Nuclear Information System (INIS)

    Zuo Guomin; Li Xinxin

    2011-01-01

    This research is aimed at elucidating surface-energy (or interfacial energy) variation during the process of molecule-layer self-assembly on a solid surface. A quasi-quantitative plotting model is proposed and established to distinguish the surface-energy variation contributed by the three characteristic layers of a thiol-on-gold self-assembled monolayer (SAM), namely the assembly-medium correlative gold/head-group layer, the chain/chain interaction layer and the tail/medium layer, respectively. The data for building the model are experimentally extracted from a set of correlative thiol self-assemblies in different media. The variation in surface-energy during self-assembly is obtained by in situ recording of the self-assembly induced nanomechanical surface-stress using integrated micro-cantilever sensors. Based on the correlative self-assembly experiment, and by using the nanomechanically sensitive self-sensing cantilevers to monitor the self-assembly induced surface-stressin situ, the experimentally extracted separate contributions of the three layers to the overall surface-energy change aid a comprehensive understanding of the self-assembly mechanism. Moreover, the quasi-quantitative modeling method is helpful for optimal design, molecule synthesis and performance evaluation of molecule self-assembly for application-specific surface functionalization.

  13. Tensile property improvement of TWIP-cored three-layer steel sheets fabricated by hot-roll-bonding with low-carbon steel or interstitial-free steel

    Science.gov (United States)

    Park, Jaeyeong; Kim, Jung-Su; Kang, Minju; Sohn, Seok Su; Cho, Won Tae; Kim, Hyoung Seop; Lee, Sunghak

    2017-01-01

    TWIP-cored three-layer steel sheets were newly fabricated by hot rolling of TWIP steel sheet surrounded by low-carbon (LC) or interstitial-free (IF) steel sheets. TWIP/LC or TWIP/IF interfaces were well bonded without pores or voids, while a few pearlites were thinly formed along the interfaces. The strengths and elongation of the TWIP-cored sheets increased as the volume fraction of TWIP-cored region increased, and were also well matched with the ones calculated by a rule of mixtures based on volume fraction or force fraction. According to digital image correlation and electron back-scatter diffraction analyses, very high strain hardening effect in the initial deformation stage and active twin formation in the interfacial region beneficially affected the overall homogeneous deformation in the TWIP-cored sheets without any yield point phenomenon occurring in the LC sheet and serrations occurring in the TWIP sheet, respectively. These TWIP-cored sheets can cover a wide range of yield strength, tensile strength, and ductility levels, e.g., 320~498 MPa, 545~878 MPa, and 48~54%, respectively, by controlling the volume fraction of TWIP-cored region, and thus present new applications to multi-functional automotive steel sheets requiring excellent properties.

  14. Effect of interface structure regulation caused by variation of imidization rate on conduction current characteristics of PI/nano-Al2O3 three-layer composite films

    Science.gov (United States)

    Ma, Xinyu; Liu, Lizhu; Zhang, Xiaorui; He, Hongju

    2018-06-01

    A series of sandwich structure PI films were prepared by different imidization process, with pure PI film as the interlayer and PI/Al2O3 composite films as outer layers. The imidization rate of the film with different cured processes was calculated by characterizing by infrared spectrum (FT-IR), and the morphology of interlayer interface with different imidization rates by scanning electron microscope (SEM). When the imidization conditions of the first and second films were 260 °C/120 min, the composite films displayed better interface structure and higher imidization rate (ID) than others. Moreover, results also showed that the conduction current of three-layer composite film steadily improved with increased ID and temperature, and was higher than that of the pure film. At the temperature of 30 °C, the electrical aging threshold at different ID was obtained. When the ID reached the maximum value of 78.9%, the electrical aging threshold reached the maximum 41.69 kV/mm.

  15. A three-layer immunoradiometric assay for determination of IgG subclass antibodies in Human Sera (''IgG subclass RAST'')

    International Nuclear Information System (INIS)

    Djurup, R.; Soendergaard, I.; Weeke, B.; University of Copenhagen, Denmark); Magnusson, C.G.M.

    1984-01-01

    We report the development of a three-layer immunoradiometric assay (TIRA) for measurement of IgG antibodies of all four subclasses in human sera. The first layer consists of diluted human serum, the second layer is monoclonal mouse antibodies to human IgG subclasses, and the third layer is 125 I-labelled rabbit anti-mouse IgG. Monoclonal anti-IgGI, anti-IgG3 and anti-IgG4 reacted only with their complementary IgG subclass, whereas the anti-IgG2 showed slight cross-reactivity to immunoglobins of other subclasses and classes and to light chain proteins. The observed cross-reactivity was found to be without importance, when the TIRA was applied to measurement of IgG subclass antibodies. Equipotency was established by use of appropriate dilutions of the monoclonal antibodies, and the assay was calibrated by use of human reference serum. The TIRA therefore permits reliable inter-individual and intra-individual comparisons of the IgG antibody response in all four subclasses. Non-specific binding obtained with pooled normal human serum was below 0.33%. Inter-assay coefficient of variation was between 18 and 27%. The TIRA was applied to measurement of IgG subclass antibodies to timothy grass pollen in sera from grass pollen allergies undergoing immunotherapy. (author)

  16. Optical performance of random anti-reflection structured surfaces (rARSS) on spherical lenses

    Science.gov (United States)

    Taylor, Courtney D.

    Random anti-reflection structured surfaces (rARSS) have been reported to improve transmittance of optical-grade fused silica planar substrates to values greater than 99%. These textures are fabricated directly on the substrates using reactive-ion/inductively-coupled plasma etching (RIE/ICP) techniques, and often result in transmitted spectra with no measurable interference effects (fringes) for a wide range of wavelengths. The RIE/ICP processes used in the fabrication process to etch the rARSS is anisotropic and thus well suited for planar components. The improvement in spectral transmission has been found to be independent of optical incidence angles for values from 0° to +/-30°. Qualifying and quantifying the rARSS performance on curved substrates, such as convex lenses, is required to optimize the fabrication of the desired AR effect on optical-power elements. In this work, rARSS was fabricated on fused silica plano-convex (PCX) and plano-concave (PCV) lenses using a planar-substrate optimized RIE process to maximize optical transmission in the range from 500 to 1100 nm. An additional set of lenses were etched in a non-optimized ICP process to provide additional comparisons. Results are presented from optical transmission and beam propagation tests (optimized lenses only) of rARSS lenses for both TE and TM incident polarizations at a wavelength of 633 nm and over a 70° full field of view in both singlet and doublet configurations. These results suggest optimization of the fabrication process is not required, mainly due to the wide angle-of-incidence AR tolerance performance of the rARSS lenses. Non-optimized recipe lenses showed low transmission enhancement, and confirmed the need to optimized etch recipes prior to process transfer of PCX/PCV lenses. Beam propagation tests indicated no major beam degradation through the optimized lens elements. Scanning electron microscopy (SEM) images confirmed different structure between optimized and non-optimized samples

  17. Performance Improvement of GaN-Based Flip-Chip White Light-Emitting Diodes with Diffused Nanorod Reflector and with ZnO Nanorod Antireflection Layer

    Directory of Open Access Journals (Sweden)

    Hsin-Ying Lee

    2014-01-01

    Full Text Available The GaN-based flip-chip white light-emitting diodes (FCWLEDs with diffused ZnO nanorod reflector and with ZnO nanorod antireflection layer were fabricated. The ZnO nanorod array grown using an aqueous solution method was combined with Al metal to form the diffused ZnO nanorod reflector. It could avoid the blue light emitted out from the Mg-doped GaN layer of the FCWLEDs, which caused more blue light emitted out from the sapphire substrate to pump the phosphor. Moreover, the ZnO nanorod array was utilized as the antireflection layer of the FCWLEDs to reduce the total reflection loss. The light output power and the phosphor conversion efficiency of the FCWLEDs with diffused nanorod reflector and 250 nm long ZnO nanorod antireflection layer were improved from 21.15 mW to 23.90 mW and from 77.6% to 80.1% in comparison with the FCWLEDs with diffused nanorod reflector and without ZnO nanorod antireflection layer, respectively.

  18. Protective Coatings

    Science.gov (United States)

    1980-01-01

    General Magnaplate Corporation's pharmaceutical machine is used in the industry for high speed pressing of pills and capsules. Machine is automatic system for molding glycerine suppositories. These machines are typical of many types of drug production and packaging equipment whose metal parts are treated with space spinoff coatings that promote general machine efficiency and contribute to compliance with stringent federal sanitation codes for pharmaceutical manufacture. Collectively known as "synergistic" coatings, these dry lubricants are bonded to a variety of metals to form an extremely hard slippery surface with long lasting self lubrication. The coatings offer multiple advantages; they cannot chip, peel or be rubbed off. They protect machine parts from corrosion and wear longer, lowering maintenance cost and reduce undesired heat caused by power-robbing friction.

  19. Temporal scaling law and intrinsic characteristic of laser induced damage on the dielectric coating

    Science.gov (United States)

    Zhou, Li; Jiang, Youen; Wang, Chao; Wei, Hui; Zhang, Peng; Fan, Wei; Li, Xuechun

    2018-01-01

    High power laser is essential for optical manipulation and fabrication. When the laser travels through optics and to the target finally, irreversible damage on the dielectric coating is always accompanied without knowing the law and principle of laser induced damage. Here, an experimental study of laser induced damage threshold (LIDT) Fth of the dielectric coating under different pulse duration t is implemented. We observe that the temporal scaling law of square pulse for high-reflectivity (HR) coating and anti-reflectivity (AR) coating are Fth = 9.53t0.47 and Fth = 6.43t0.28 at 1064 nm, respectively. Moreover, the intrinsic LIDT of HR coating is 62.7 J/cm2 where the coating is just 100% damaged by gradually increasing the fluence densities of a 5ns-duration pulse, which is much higher than the actual LIDT of 18.6 J/cm2. Thus, a more robust and reliable high power laser system will be a reality, even working at very high fluence, if measures are taken to improve the actual LIDT to a considerable level near the intrinsic value.

  20. Facile Deposition of Ultrafine Silver Particles on Silicon Surface Not Submerged in Precursor Solutions for Applications in Antireflective Layer

    Directory of Open Access Journals (Sweden)

    Bing Jiang

    2014-01-01

    Full Text Available Using a facile deposition method, the ultrafine silver particles are successfully deposited on the Si surface that is not submerged in precursor solutions. The ultrafine silver particles have many advantages, such as quasiround shape, uniformity in size, monodisperse distribution, and reduction of agglomeration. The internal physical procedure in the deposition is also investigated. The results show that there are more particles on the rough Si surface due to the wetting effect of solid-liquid interface. The higher concentration of ethanol solvent can induce the increase of quantity and size of particles on Si surface not in solutions. The ultrafine particles can be used to prepare porous Si antireflective layer in solar cell applications.

  1. Polarization and fluence effects in femtosecond laser induced micro/nano structures on stainless steel with antireflection property

    Science.gov (United States)

    Yao, Caizhen; Ye, Yayun; Jia, Baoshen; Li, Yuan; Ding, Renjie; Jiang, Yong; Wang, Yuxin; Yuan, Xiaodong

    2017-12-01

    In this paper, micro/nano structures on stainless steel were prepared in single spot irradiation mode and scan mode by using femtosecond laser technique. The influence of polarization and fluence on the formation of micro/nano structures were explored. Surface morphology, microstructure, roughness and composition of prepared samples were characterized. The antireflection property and wettability of laser treated samples were also tested and compared with that of original stainless steel.Results showed that the laser-induced spot consists of two distinct regions due to the Gaussian beam profile: a core region of moth-eye-like structure and a peripheral region of nanoparticles-covered laser-induced periodic surface structure (NC-LIPSS). The proportion of the core region and dimension of micro/nano structure increase with increasing laser fluence. Polarization can be used to tune the direction of NC-LIPSS. Atomic ratios of Cr and Mn increase and atomic ratio of Ni decreases after laser irradiation. Oxygen is not detected on laser irradiated samples, indicating that oxidation reactions are not significant during the interaction process between femtosecond laser and 304 stainless steel. These are good for the application of stainless steel as its physical properties would not change or even enhanced. The overlaps between two laser scan lines significantly influence the surface roughness and should be controlled carefully during the preparation process. The laser irradiated surface has a better antireflection property in comparison with that of original stainless steel, which may due to the scattering and absorption of micro/nano structures. Contact angle of micro/nano structured stainless steel decreases with the increase of laser fluence. The hydrophilic property can be explained by Wenzel's model. The interference between the surface plasmon wave and the incident light wave leads to the formation of NC-LIPSS.

  2. Coating materials

    International Nuclear Information System (INIS)

    Ozeki, Takao; Kimura, Tadashi; Kobayashi, Juichi; Maeda, Yutaka; Nakamoto, Hideo.

    1969-01-01

    A non-solvent type coating material composition having properties as good as thermosetting acrylic or amino alkid resins is provided by employing active energy irradiation, particularly electron beams, using a radically polymerizable low molecular compound (A) (hereafter called an oligomer) containing at least two vinyl radicals in one molecule. This oligomer is produced by reacting an epoxy-containing vinyl monomer with alpha-, beta-ethylene unsaturated carboxylic acids or their anhydrides. The composition (I) contains 10% - 100% of this oligomer. In embodiments, an oligomer having a fiberous trivinyl construction is produced by reacting 180 parts by weight of glycidyl methacrylate ester with 130 parts of itaconic acid in the presence of a polymerization-inhibitor and an addition reaction catalyst at 90 0 C for 6 hours. In practice, the coating material compositions (1), consist of the whole oligomer [I-1]; (2), consist of 10-90% of (A) component and 90%-10% of vinyl monomers containing at least 30% (meth) acrylic monomer [I-2]; (3), 10%-90% of component (A) and 90%-10% of other monomers containing at least two vinyl radicals [I-3]; (4), a mixture of (I-2) and (I-3), [I-4]; and (5), consist of 50% or less unsaturated polyester of 500-5,000 molecular weight range or drying oil, or alkyd resin of 500-5,000 molecular weight range modified by drying oil, [I-5]. As a catalyst a tertiary amino vinyl compound is preferred. Five examples are given. (Iwakiri, K.)

  3. Coatings and Corrosion Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The mission of the Coatings and Corrosion Laboratory is to develop and analyze the effectiveness of innovative coatings test procedures while evaluating the...

  4. A three-layer immunoradiometric assay for antibodies in different immunoglobulin classes and its application to the detection of chicken thyroglobulin autoantibodies and of antibodies to sheep erythrocytes

    International Nuclear Information System (INIS)

    Carvalho, L.C.P. de; Roitt, I.M.; Wick, G.

    1980-01-01

    A versatile solid-phase assay for detection of antibodies in different immunoglobulin classes is described. The assay has been applied to: (1) the detection of IgG and IgM antithyroglobulin autoantibodies in chickens with spontaneous autoimmune thyroiditis, and (2) the detection of anti-sheep cell antibodies in normal chickens. Thyroglobulin-coated plastic tubes or formaldehyde-fixed sheep erythrocytes were used as the solid phase. Antisera were added in succession to the solid-phase antigen so as to form 3 antibody layers: (1) chicken antibody against the solid-phase antigen; (2) heavy-chain-specific rabbit anti-chicken immunoglobulin; and (3) 125 I-labelled goat anti-rabbit immunoglobulin. The assay is suitable for routine determinations on large numbers of samples; its sensitivity enables small volumes of serum to be tested and allows considerable economy in the use of valuable class-specific antisera. The radiolabelled reagent can be readily applied to other assays employing rabbit antisera. (Auth.)

  5. Graphene Coatings

    DEFF Research Database (Denmark)

    Stoot, Adam Carsten; Camilli, Luca; Bøggild, Peter

    2014-01-01

    Owing to its remarkable electrical and mechanical properties, graphene has been attracting tremendous interest in materials science. In particular, its chemical stability and impermeability make it a promising protective membrane. However, recent investigations reveal that single layer graphene...... cannot be used as a barrier in the long run, due to galvanic corrosion phenomena arising when oxygen or water penetrate through graphene cracks or domain boundaries. Here, we overcome this issue by using a multilayered (ML) graphene coating. Our lab- as well as industrial-scale tests demonstrate that ML...... graphene can effectively protect Ni in harsh environments, even after long term exposure. This is made possible by the presence of a high number of graphene layers, which can efficiently mask the cracks and domain boundaries defects found in individual layers of graphene. Our findings thus show...

  6. Coating materials

    International Nuclear Information System (INIS)

    Ozeki, Takao; Kimura, Tadashi; Kobayashi, Juichi; Maeda, Yutaka; Nakamoto, Hideo.

    1969-01-01

    A non-solvent type coating material composition is provided which can be hardened by irradiation with active energy, particularly electron beams, using a composition which contains 10%-100% of a radically polymerizable low molecular compound (A), (hereafter called an oligomer), having at least two vinyl radicals in one molecule. These compositions have a high degree of polymerization and characteristics equivalent to thermosetting acrylic or amino alkyd resin. The oligomer (A) is produced by reacting an epoxy-containing vinyl monomer with saturated polycarboxylic acids or anhydrides. In one embodiment, 146 parts by weight of adipic acid and 280 parts of glycidyl methacrylate ester undergo addition reaction in the presence of a polymerization-inhibitor and a catalyst at 90 0 C for 6 hours to produce an oligomer having a fiberous divinyl construction. The coating composition utilizes this oligomer in the forms of (I-1), a whole oligomer; (I-2), 0%-90% of this oligomer and 90%-10% of a vinyl monomer containing at least 30% of (meth) acrylic monomer; (I-3), 10%-90% of such oligomer and 90%-10% of other monomers containing at least two vinyl radicals in one molecule; (I-4), a mixture of (I-2) and (I-3) in proportion of 1/9 to 9/1, and (I-5), above four compositions each containing 50% or less unsaturated polyester or drying oil having 500-5,000 molecules or a drying oil-modified alkyd resin having 500-5,000 molecules. Four examples are given. (Iwakiri, K.)

  7. Electrocurtain coating process for coating solar mirrors

    Science.gov (United States)

    Kabagambe, Benjamin; Boyd, Donald W.; Buchanan, Michael J.; Kelly, Patrick; Kutilek, Luke A.; McCamy, James W.; McPheron, Douglas A.; Orosz, Gary R.; Limbacher, Raymond D.

    2013-10-15

    An electrically conductive protective coating or film is provided over the surface of a reflective coating of a solar mirror by flowing or directing a cation containing liquid and an anion containing liquid onto the conductive surface. The cation and the anion containing liquids are spaced from, and preferably out of contact with one another on the surface of the reflective coating as an electric current is moved through the anion containing liquid, the conductive surface between the liquids and the cation containing liquid to coat the conductive surface with the electrically conductive coating.

  8. Fabrication of Polymeric Antireflection Film Manufactured by Anodic Aluminum Oxide Template on Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Jenn-Kai Tsai

    2017-03-01

    Full Text Available In this study, high energy conversion efficient dye-sensitized solar cells (DSSCs were successfully fabricated by attaching a double anti-reflection (AR layer, which is composed of a subwavelength moth-eye structured polymethyl methacrylate (PMMA film and a polydimethylsiloxane (PDMS film. An efficiency of up to 6.79% was achieved. The moth-eye structured PMMA film was fabricated by using an anodic aluminum oxide (AAO template which is simple, low-cost and scalable. The nano-pattern of the AAO template was precisely reproduced onto the PMMA film. The photoanode was composed of Titanium dioxide (TiO2 nanoparticles (NPs with a diameter of 25 nm deposited on the fluorine-doped tin oxide (FTO glass substrate and the sensitizer N3. The double AR layer was proved to effectively improve the short-circuit current density (JSC and conversion efficiency from 14.77 to 15.79 mA/cm2 and from 6.26% to 6.79%, respectively.

  9. Lithography-Free Fabrication of Large Area Subwavelength Antireflection Structures Using Thermally Dewetted Pt/Pd Alloy Etch Mask

    Directory of Open Access Journals (Sweden)

    Kang Jeong-Jin

    2009-01-01

    Full Text Available Abstract We have demonstrated lithography-free, simple, and large area fabrication method for subwavelength antireflection structures (SAS to achieve low reflectance of silicon (Si surface. Thin film of Pt/Pd alloy on a Si substrate is melted and agglomerated into hemispheric nanodots by thermal dewetting process, and the array of the nanodots is used as etch mask for reactive ion etching (RIE to form SAS on the Si surface. Two critical parameters, the temperature of thermal dewetting processes and the duration of RIE, have been experimentally studied to achieve very low reflectance from SAS. All the SAS have well-tapered shapes that the refractive index may be changed continuously and monotonously in the direction of incident light. In the wavelength range from 350 to 1800 nm, the measured reflectance of the fabricated SAS averages out to 5%. Especially in the wavelength range from 550 to 650 nm, which falls within visible light, the measured reflectance is under 0.01%.

  10. Low Temperature Powder Coating

    Science.gov (United States)

    2011-02-09

    of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) • Legacy primers contain hexavalent chrome • Conventional powder coatings...coatings both in laboratory and field service evaluations • LTCPC allows environmental cost reductions through VOC/HAP elimination and hexavalent ... chrome reduction. • The LTCPC process greatly shortens the coating operation (LTCPC cures much more rapidly then conventional wet coatings) resulting in

  11. Oxidation protection of multilayer CVD SiC/B/SiC coatings for 3D C/SiC composite

    International Nuclear Information System (INIS)

    Liu Yongsheng; Cheng Laifei; Zhang Litong; Wu Shoujun; Li Duo; Xu Yongdong

    2007-01-01

    A CVD boron coating was introduced between two CVD SiC coating layers. EDS and XRD results showed that the CVD B coating was a boron crystal without other impurity elements. SEM results indicated that the CVD B coating was a flake-like or column-like crystal with a compact cross-section. The crack width in the CVD SiC coating deposited on CVD B is smaller than that in a CVD SiC coating deposited on CVD SiC coating. After oxidation at 700 deg. C and 1000 deg. C, XRD results indicated that the coating was covered by product B 2 O 3 or B 2 O 3 .xSiO 2 film. The cracks were sealed as observed by SEM. There was a large amount of flake-like material on hybrid coating surface after oxidation at 1300 deg. C. Oxidation weight loss and residual flexural strength results showed that hybrid SiC/B/SiC multilayer coating provided better oxidation protection for C/SiC composite than a three layer CVD SiC coating at temperatures from 700 deg. C to 1000 deg. C for 600 min, but worse oxidation protection above 1000 deg. C due to the large amount of volatilization of B 2 O 3 or B 2 O 3 .xSiO 2

  12. Environmental Barrier Coatings for Ceramic Matrix Composites - An Overview

    Science.gov (United States)

    Lee, Kang; Zhu, Dongming; Wiesner, Valerie Lynn; van Roode, Mark; Kashyap, Tania; Zhu, Dongming; Wiesner, Valerie

    2016-01-01

    Ceramic Matrix Composites (CMCs) are increasingly being considered as structural materials for advanced power generation equipment. Broadly speaking the two classes of materials are oxide-based CMCs and non-oxide based CMCs. The non-oxide CMCs are primarily silicon-based. Under conditions prevalent in the gas turbine hot section the water vapor formed in the combustion of gaseous or liquid hydrocarbons reacts with the surface-SiO2 to form volatile products. Progressive surface recession of the SiC-SiC CMC component, strength loss as a result of wall thinning and chemical changes in the component occur, which leads to the loss of structural integrity and mechanical strength and becomes life limiting to the equipment in service. The solutions pursued to improve the life of SiC-SiC CMCs include the incorporation of an external barrier coating to provide surface protection to the CMC substrate. The coating system has become known as an Environmental Barrier Coating (EBC). The relevant early coatings work was focused on coatings for corrosion protection of silicon-based monolithic ceramics operating under severely corrosive conditions. The development of EBCs for gas turbine hot section components was built on the early work for silicon-based monolithics. The first generation EBC is a three-layer coating, which in its simplest configuration consists of a silicon (Si) base coat applied on top of the CMC, a barium-strontium-aluminosilicate (BSAS) surface coat resistant to water vapor attack, and a mullite-based intermediate coating layer between the Si base coat and BSAS top coat. This system can be represented as Si-Mullite-BSAS. While this baseline EBC presented a significant improvement over the uncoated SiC-SiC CMC, for the very long durations of 3-4 years or more expected for industrial operation further improvements in coating durability are desirable. Also, for very demanding applications with higher component temperatures but shorter service lives more rugged EBCs

  13. Flow coating apparatus and method of coating

    Science.gov (United States)

    Hanumanthu, Ramasubrahmaniam; Neyman, Patrick; MacDonald, Niles; Brophy, Brenor; Kopczynski, Kevin; Nair, Wood

    2014-03-11

    Disclosed is a flow coating apparatus, comprising a slot that can dispense a coating material in an approximately uniform manner along a distribution blade that increases uniformity by means of surface tension and transfers the uniform flow of coating material onto an inclined substrate such as for example glass, solar panels, windows or part of an electronic display. Also disclosed is a method of flow coating a substrate using the apparatus such that the substrate is positioned correctly relative to the distribution blade, a pre-wetting step is completed where both the blade and substrate are completed wetted with a pre-wet solution prior to dispensing of the coating material onto the distribution blade from the slot and hence onto the substrate. Thereafter the substrate is removed from the distribution blade and allowed to dry, thereby forming a coating.

  14. Engineered pipeline field joint coating solutions for demanding conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lwemuchi, Andre L.; Gudme, Carl C.; Buchanan, Robert [Canusa-CPS, Toronto, OT (Canada)

    2009-12-19

    Trends in the oil and gas pipeline industry see that the demand for new technologies and engineered solutions for pipeline external coatings are increasing. In general, superior mechanical resistance and long term performance are being required in addition to operating at higher temperatures. This demand for more robust coatings has been created because of factors such as more remote fields, deep onshore reservoirs, deep water offshore fields and heavy oil that must be pumped at higher temperatures. The development of new techniques for pipeline construction is also exposing the coatings to more aggressive construction conditions. Because of this, the use of three layer and multi-layer polypropylene mainline coating systems have been growing considerably. Following this trend, the field joint coating manufacturers developed polypropylene systems and more recently had to work on engineered solutions required for recent offshore projects in Europe where very thick polypropylene field joint heat-shrinkable systems were provided. In addition, projects in remote locations such as the recently completed projects in the Brazilian Amazon required special logistics and field services. The growth of the mining industry in South America with slurry pipelines constructed in the recent years also demanded thicker, more robust coatings. The popularization of directional drilling and shore approach applications moved the industry to develop improved abrasion resistant coating systems such as using sacrificial elements to protect the primary coating integrity after the pipeline pull. PETROBRAS plans to replace existing thermally insulated pipelines crossing Great Sao Paulo. Therefore, pumping heavy oil at high temperatures created the need to develop improved mainline and field joint coatings to avoid having the same sort of problems they are facing in existing thermally insulated lines. Due to these needs, the field joint coating manufactures have been challenged to provide

  15. Preparation and characterization of SiO2:Sm3+ nanotube arrays with 1.06 μm laser antireflective property

    International Nuclear Information System (INIS)

    Tan, Wei-min; Huang, Ning; Wang, Li-jun; Song, Tian-shun; Lu, Chun-hua; Wang, Liu-fang; Zhang, Jun-zhi

    2013-01-01

    SiO 2 : Sm 3+ nanotube arrays with excellent antireflective property at 1.06 μm were synthesized by a template-assisted sol–gel process. The molecular structure, morphology and optical properties of the fabricated SiO 2 :Sm 3+ nanotube arrays were investigated by a Fourier transform infrared spectroscope (FTIR), a Scanning electron microscope (SEM), and a spectro-fluorometer, respectively. The experimental results demonstrate that the SiO 2 :Sm 3+ nanotube arrays were formed via the AAO membrane during the sol–gel process. The remarkable antireflective characteristic of about 0.166% at 1.06 μm was attributed to the drastic decrease of effective refraction index which enhances the matching effect between air and substrate. As well as the absorption performance of Sm3+ at 1.06 μm which consumes the energies of incident light. - Graphical abstract: Directional aligned SiO 2 :Sm 3+ nanotube arrays were synthesized in AAO template by sol–gel process, and the antiflective performance of arrays is prominent comparing to the blank AAO template. Highlights: ► SiO 2 :Sm 3+ nanotube arrays are synthesized by a template-assisted sol–gel process. ► SiO 2 :Sm 3+ nanotube arrays have remarkable antireflective properties at 1.06 μm. ► The subwavelength structure results in a decrease of effective refraction index. ► The absorption performance of Sm 3+ at 1.06 μm consume the energies of incident light

  16. Conservation of Monuments by a Three-Layered Compatible Treatment of TEOS-Nano-Calcium Oxalate Consolidant and TEOS-PDMS-TiO2 Hydrophobic/Photoactive Hybrid Nanomaterials

    Directory of Open Access Journals (Sweden)

    Chrysi Kapridaki

    2018-04-01

    Full Text Available In the conservation of monuments, research on innovative nanocomposites with strengthening, hydrophobic and self-cleaning properties have attracted the interest of the scientific community and promising results have been obtained as a result. In this study, stemming from the need for the compatibility of treatments in terms of nanocomposite/substrate, a three-layered compatible treatment providing strengthening, hydrophobic, and self-cleaning properties is proposed. This conservation approach was implemented treating lithotypes and mortars of different porosity and petrographic characteristics with a three-layered treatment comprising: (a a consolidant, tetraethoxysilane (TEOS-nano-Calcium Oxalate; (b a hydrophobic layer of TEOS-polydimethylsiloxane (PDMS; and (c a self-cleaning layer of TiO2 nanoparticles from titanium tetra-isopropoxide with oxalic acid as hole-scavenger. After the three-layered treatment, the surface hydrophobicity was improved due to PDMS and nano-TiO2 in the interface substrate/atmosphere, as proven by the homogeneity and the Si–O–Ti hetero-linkages of the blend protective/self-cleaning layers observed by Scanning Electron Microscope (SEM, Transmission Electron Microscope (TEM and Fourier-Transform Infrared Spectroscopy (FTIR. The aesthetic, microstructural, mechanical and permeabile compatibility of the majority of treated substrates ranged within acceptability limits. The improved photocatalytic activity, as proven by the total discoloration of methylene blue in the majority of cases, was attributed to the anchorage of TiO2, through the Si–O–Ti bonds to SiO2, in the interface with the atmosphere, thus enhancing photoactivation.

  17. Fabrication of High Transparency Diamond-Like Carbon Film Coating on D263T Glass at Room Temperature as an Antireflection Layer

    Directory of Open Access Journals (Sweden)

    Chii-Ruey Lin

    2013-01-01

    Full Text Available This study intends to deposit high transmittance diamond-like carbon (DLC thin films on D263T glass substrate at room temperature via a diamond powder target using the radio frequency (RF magnetron sputtering technique. Moreover, various process parameters were used to tune the properties of the thin films by using the Taguchi method. Experimental results show that the content of sp3 bonded carbon decreases in accordance with the effect of the substrate temperature. In addition, the hardness of all as-deposited single-layer DLC films ranges from 13.2 to 22.5 GPa, and the RMS surface roughness was improved significantly with the decrease in sputtering pressure. The water repellent of the deposited DLC films improved significantly with the increase of the sp3 content, and its contact angle was larger than that of the noncoated one by 1.45 times. Furthermore, the refraction index (n of all as-deposited DLC films ranges from 1.95 to 2.1 at λ = 600 nm. These results demonstrate that the thickness increased as the reflectance increased. DLC film under an RF power of 150 W possesses high transmissive ability (>81% and low average reflectance ability (<9.5% in the visible wavelengths (at λ = 400–700 nm.

  18. A study of the optical properties and adhesion of zinc sulfide anti-reflection thin film coated on a germanium substrate

    Energy Technology Data Exchange (ETDEWEB)

    Firoozifar, S.A.R. [Atomic and Molecular Group, Faculty of Physics, Yazd University, Yazd (Iran, Islamic Republic of); Behjat, A., E-mail: abehjat@yazduni.ac.ir [Atomic and Molecular Group, Faculty of Physics, Yazd University, Yazd (Iran, Islamic Republic of); Photonics Research Group, Engineering Research Center, Yazd University, Yazd (Iran, Islamic Republic of); Kadivar, E. [Physics Department, Persian Gulf University, Bushehr (Iran, Islamic Republic of); Ghorashi, S.M.B.; Zarandi, M. Borhani [Atomic and Molecular Group, Faculty of Physics, Yazd University, Yazd (Iran, Islamic Republic of)

    2011-11-01

    To conduct this study, zinc sulfide (ZnS) thin films deposited on germanium (Ge) substrates were prepared by an evaporation method. The effects of deposition rate and annealing on the optical properties and adhesion of the ZnS thin films were investigated. The transmission intensity and the X-ray diffraction (XRD) pattern of the samples showed that the transmittance of the samples decreases by increasing the evaporation rates. However, with the increase of the annealing temperature, crystallinity of the thin films improves which, in turn, results in the enhancement of the transmission intensity in a far infrared region. The maximum grain size was obtained at the annealing temperature of 225 deg. C. Our experimental results also show that evaporation rate and annealing influences the adhesion of ZnS thin films to Ge substrates.

  19. Alleviation of process-induced cracking of the antireflection TiN coating (ARC-TiN) in Al-Cu and Al-Cu-Si films

    CERN Document Server

    Peng, Y C; Yang, Y R; Hsieh, W Y; Hsieh, Y F

    1999-01-01

    The alleviation of cracking of the TiN-ARC layer on Al-Cu and Al-Cu-Si films after the development process has been achieved. For the TiN-ARC/Al-Cu system, the stress-induced defects decreased with increasing TiN-ARC layer thickness. In contrast, for the TiN-ARC/Al-Cu-Si system, Si nodules formed during cooling, thereby inducing poor coverage with high aspect-ratio holes. As a result, the photoresist developer penetrated through the films. Chemical vapor deposition of TiN-ARC or predeposition of a Ti Interposing layer was used to eliminate the formation of Si nodules.

  20. Antireflective sub-wavelength structures for improvement of the extraction efficiency and color rendering index of monolithic white light-emitting diode

    DEFF Research Database (Denmark)

    Ou, Yiyu; Corell, Dennis Dan; Dam-Hansen, Carsten

    2011-01-01

    We have theoretically investigated the influence of antireflective sub-wavelength structures on a monolithic white light-emitting diode (LED). The simulation is based on the rigorous coupled wave analysis (RCWA) algorithm, and both cylinder and moth-eye structures have been studied in the work. Our...... simulation results show that a moth-eye structure enhances the light extraction efficiency over the entire visible light range with an extraction efficiency enhancement of up to 26 %. Also for the first time to our best knowledge, the influence of sub-wavelength structures on both the color rendering index...

  1. High performance and thermally stable tandem solar selective absorber coating for concentrated solar thermal power (CSP) application

    Science.gov (United States)

    Prasad, M. Shiva; Kumar, K. K. Phani; Atchuta, S. R.; Sobha, B.; Sakthivel, S.

    2018-05-01

    A novel tandem absorber system (Mn-Cu-Co-Ox-ZrO2/SiO2) developed on an austenitic stainless steel (SS-304) substrate to show an excellent optical performance (αsol: 0.96; ɛ: 0.23@500 °C). In order to achieve this durable tandem, we experimented with two antireflective layers such as ZrO2-SiO2 and nano SiO2 layer on top of Mn-Cu-Co-Ox-ZrO2 layer. We optimized the thickness of antireflective layers to get good tandem system in terms of solar absorptance and emittance. Field emission scanning electron microscopy (FESEM), UV-Vis-NIR and Fourier transform infrared spectroscopy (FTIR) were used to characterize the developed coatings. Finally, the Mn-Cu-Co-Ox-ZrO2/SiO2 exhibits high temperature resistance up to 800 °C, thus allow an increase in the operating temperature of CSP which may lead to high efficiency. We successfully developed a high temperature resistant tandem layer with easy manufacturability at low cost which is an attractive candidate for concentrated solar power generation (CSP).

  2. The gridless plasma ion source (GIS) for plasma ion assisted optical coating

    International Nuclear Information System (INIS)

    You Dawei; Li Xiaoqian; Wang Yu; Lin Yongchang

    2004-01-01

    High-quality optical coating is a key technology for modern optics. Ion-assisted deposition technology was used to improve the vaporized coating in 1980's. The GIS (gridless ion source), which is an advanced plasma source for producing a high-quality optical coating in large area, can produce a large area uniformity>1000 mm (diameter), a high ion current density ∼0.5 mA/cm 2 , 20 eV-200 eV energetic plasma ions and can activate reactive gas and film atoms. Now we have developed a GIS system. The GIS and the plasma ion-assisted deposition technology are investigated to achieve a high-quality optical coating. The GIS is a high power and high current source with a power of 1 kW-7.5 kW, a current of 10 A- 70 A and an ion density of 200 μA/cm 2 -500 μA/cm 2 . Because of the special magnetic structure, the plasma-ion extraction efficiency has been improved to obtain a maximum ion density of 500 μA/cm 2 in the medium power (∼4 kW) level. The GIS applied is of a special cathode structure, so that the GIS operation can be maintained under a rather low power and the lifetime of cathode will be extended. The GIS has been installed in the LPSX-1200 type box coating system. The coated TiO 2 , SiO 2 films such as antireflective films with the system have the same performance reported by Leybold Co, 1992, along with a controllable refractive index and film structure. (authors)

  3. European coatings conference - Marine coatings. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This volume contains 13 lectures (manuscripts or powerpoint foils) with the following topics: 1. Impact of containerization on polyurethane and polyurea in marine and protective coatings (Malte Homann); 2. The application of combinatorial/high-throughput methods to the development of marine coatings (Bret Chisholm); 3. Progress and perspectives in the AMBIO (advanced nanostructured surfaces for the control of biofouling) Project (James Callow); 4. Release behaviour due to shear and pull-off of silicone coatings with a thickness gradient (James G. Kohl); 5. New liquid rheology additives for high build marine coatings (Andreas Freytag); 6. Effective corrosion protection with polyaniline, polpyrrole and polythiophene as anticorrosice additives for marine paints (Carlos Aleman); 7. Potential applications of sol gel technology for marine applications (Robert Akid); 8: Performance of biocide-free Antifouling Coatings for leisure boats (Bernd Daehne); 9. Novel biocidefree nanostructured antifouling coatings - can nano do the job? (Corne Rentrop); 10. One component high solids, VOC compliant high durability finish technology (Adrian Andrews); 11. High solid coatings - the hybrid solution (Luca Prezzi); 12. Unique organofunctional silicone resins for environmentally friendly high-performance coatings (Dieter Heldmann); 13. Silicone-alkyd paints for marine applications: from battleship-grey to green (Thomas Easton).

  4. Ag/C:F Antibacterial and hydrophobic nanocomposite coatings

    Science.gov (United States)

    Kylián, Ondřej; Kratochvíl, Jiří; Petr, Martin; Kuzminova, Anna; Slavínská, Danka; Biederman, Hynek; Beranová, Jana

    Silver-based nanomaterials that exhibit antibacterial character are intensively studied as they represent promising weapon against multi-drug resistant bacteria. Equally important class of materials represent coatings that have highly water repellent nature. Such materials may be used for fabrication of anti-fogging or self-cleaning surfaces. The aim of this study is to combine both of these valuable material characteristics. Antibacterial and highly hydrophobic Ag/C:F nanocomposite films were fabricated by means of gas aggregation source of Ag nanoparticles and sputter deposition of C:F matrix. The nanocomposite coatings had three-layer structure C:F base layer/Ag nanoparticles/C:F top layer. It is shown that the increasing number of Ag nanoparticles in produced coatings leads not only in enhancement of their antibacterial activity, but also causes substantial increase of their hydrophobicity. Under optimized conditions, the coatings are super-hydrophobic with water contact angle equal to 165∘ and are capable to induce 6-log reduction of bacteria presented in solution within 4h.

  5. PIT Coating Requirements Analysis

    International Nuclear Information System (INIS)

    MINTEER, D.J.

    2000-01-01

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products

  6. PIT Coating Requirements Analysis

    Energy Technology Data Exchange (ETDEWEB)

    MINTEER, D.J.

    2000-10-20

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products.

  7. Coatings for laser fusion

    International Nuclear Information System (INIS)

    Lowdermilk, W.H.

    1981-01-01

    Optical coatings are used in lasers systems for fusion research to control beam propagation and reduce surface reflection losses. The performance of coatings is important in the design, reliability, energy output, and cost of the laser systems. Significant developments in coating technology are required for future lasers for fusion research and eventual power reactors

  8. Fuel particle coating data

    International Nuclear Information System (INIS)

    Hollabaugh, C.M.; Wagner, P.; Wahman, L.A.; White, R.W.

    1977-01-01

    Development of coating on nuclear fuel particles for the High-Temperature Fuels Technology program at the Los Alamos Scientific Laboratory included process studies for low-density porous and high-density isotropic carbon coats, and for ZrC and ''alloy'' C/ZrC coats. This report documents the data generated by these studies

  9. Effect of SiO2 coating in bolometric Ge light detectors for rare event searches

    International Nuclear Information System (INIS)

    Beeman, J.W.; Gentils, A.; Giuliani, A.; Mancuso, M.; Pessina, G.; Plantevin, O.; Rusconi, C.

    2013-01-01

    In germanium-based light detectors for scintillating bolometers, a SiO 2 anti-reflective coating is often applied on the side of the germanium wafer exposed to light with the aim to improve its light collection efficiency. In this paper, we report about a measurement, performed in the temperature range 25–35 mK, of the light-collection increase obtained thanks to this method, which resulted to be of the order of 20%. The procedure followed has been carefully selected in order to minimize systematic effects. The employed light sources have the same spectral features (peaking at ∼630nm wavelength) that will characterize future neutrinoless double beta decay experiments on the isotope 82 Se and based on ZnSe crystals, such as LUCIFER. The coupling between source and light detector reproduces the configuration used in scintillating bolometers. The present measurement clarifies the role of SiO 2 coating and describes a method and a set-up that can be extended to the study of other types of coatings and luminescent materials

  10. Effect of SiO2 coating in bolometric Ge light detectors for rare event searches

    Science.gov (United States)

    Beeman, J. W.; Gentils, A.; Giuliani, A.; Mancuso, M.; Pessina, G.; Plantevin, O.; Rusconi, C.

    2013-05-01

    In germanium-based light detectors for scintillating bolometers, a SiO2 anti-reflective coating is often applied on the side of the germanium wafer exposed to light with the aim to improve its light collection efficiency. In this paper, we report about a measurement, performed in the temperature range 25-35 mK, of the light-collection increase obtained thanks to this method, which resulted to be of the order of 20%. The procedure followed has been carefully selected in order to minimize systematic effects. The employed light sources have the same spectral features (peaking at ˜630 nm wavelength) that will characterize future neutrinoless double beta decay experiments on the isotope 82Se and based on ZnSe crystals, such as LUCIFER. The coupling between source and light detector reproduces the configuration used in scintillating bolometers. The present measurement clarifies the role of SiO2 coating and describes a method and a set-up that can be extended to the study of other types of coatings and luminescent materials.

  11. Bio-inspired, sub-wavelength surface structures for ultra-broadband, omni-directional anti-reflection in the mid and far IR.

    Science.gov (United States)

    Gonzalez, Federico Lora; Gordon, Michael J

    2014-06-02

    Quasi-ordered moth-eye arrays were fabricated in Si using a colloidal lithography method to achieve highly efficient, omni-directional transmission of mid and far infrared (IR) radiation. The effect of structure height and aspect ratio on transmittance and scattering was explored experimentally and modeled quantitatively using effective medium theory. The highest aspect ratio structures (AR = 9.4) achieved peak transmittance of 98%, with >85% transmission for λ = 7-30 μm. A detailed photon balance was constructed by measuring transmission, forward scattering, specular reflection and diffuse reflection to quantify optical losses due to near-field effects. In addition, angle-dependent transmission measurements showed that moth-eye structures provide superior anti-reflective properties compared to unstructured interfaces over a wide angular range (0-60° incidence). The colloidal lithography method presented here is scalable and substrate-independent, providing a general approach to realize moth-eye structures and anti-reflection in many IR-compatible material systems.

  12. The flaw-detected coating and its applications in R&M of aircrafts

    Science.gov (United States)

    Hu, Feng; Liu, Mabao; Lü, Zhigang

    2009-07-01

    A monitoring method called ICM (Intelligent Coating Monitoring), which is based mainly on the intelligent coating sensors, has the capability to monitor crack initiation and growth in fatigue test coupons has been suggested in this study. The intelligent coating sensor is normally consisted of three layers: driving layer, sensing layer and protective layer where necessary. Fatigue tests with ICM for various materials demonstrate the capability to detect cracks with lfuel tank of an aircraft), or (ii) to take advantage of early detection and apply less invasive life-extension repairs, as well as reduce interruption of service when flaws are detected. Implementation of ICM is expected to improve fleet management practices and modify damage tolerance assumptions.

  13. Alfinated coating structure on HS6-5-2 (SW7M high speed steel

    Directory of Open Access Journals (Sweden)

    T. Szymczak

    2010-10-01

    Full Text Available The paper presents the results of immersion alfinated coating structure in AlSi5 silumin on HS6-5-2 (SW7M high speed steel. Alfinating bath temperature was 750 ± 5 ° C, time of sample immersion was τ = 180s. Thickness of obtained coating under specified conditions was g = 150μm. Manufactured coating consists of three layers of different construction phase. The first layer from the substrate „g1`” constructed with a AlFe phase consist of alloy additives constituents of HS6-5-2 (SW7M steel: W, Mo, V, Cr and Si. On it crystallizes the second layer „g1``” of AlFeWMoCr intermetallic phases also containing Si and small amount of V. Last, the outer layer „g2” of the coating is composed with silumin including AlFeWMoCrVSi intermetallic phases. Within all layers of the coating occurs carbides. Penetration of carbides to individual coating layers is mainly due to steel surface partial melting and crystallizing layers „g1`” and „g1``” by alfinating liquid and shifting into her of carbides as well as partial carbides rejection by crystallization front of intermetallic phases occurs in coating.

  14. ATHENA optimized coating design

    DEFF Research Database (Denmark)

    Ferreira, Desiree Della Monica; Christensen, Finn Erland; Jakobsen, Anders Clemen

    2012-01-01

    The optimization of coating design for the ATHENA mission si described and the possibility of increasing the telescope effective area in the range between 0.1 and 10 keV is investigated. An independent computation of the on-axis effective area based on the mirror design of ATHENA is performed...... in order to review the current coating baseline. The performance of several material combinations, considering a simple bi-layer, simple multilayer and linear graded multilayer coatings are tested and simulation of the mirror performance considering both the optimized coating design and the coating...

  15. Metallic coating of microspheres

    International Nuclear Information System (INIS)

    Meyer, S.F.

    1980-01-01

    Extremely smooth, uniform metal coatings of micrometer thicknesses on microscopic glass spheres (microspheres) are often needed as targets for inertial confinement fusion (ICF) experiments. The first part of this paper reviews those methods used successfully to provide metal coated microspheres for ICF targets, including magnetron sputtering, electro- and electroless plating, and chemical vapor pyrolysis. The second part of this paper discusses some of the critical aspects of magnetron sputter coating of microspheres, including substrate requirements, the sticking of microspheres during coating (preventing a uniform coating), and the difficulties in growing the desired dense, smooth, uniform microstructure on continuously moving spherical substrates

  16. Antibacterial polymer coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mollye C.; Allen, Ashley N.; Barnhart, Meghan; Tucker, Mark David; Hibbs, Michael R.

    2009-09-01

    A series of poly(sulfone)s with quaternary ammonium groups and another series with aldehyde groups are synthesized and tested for biocidal activity against vegetative bacteria and spores, respectively. The polymers are sprayed onto substrates as coatings which are then exposed to aqueous suspensions of organisms. The coatings are inherently biocidal and do not release any agents into the environment. The coatings adhere well to both glass and CARC-coated coupons and they exhibit significant biotoxicity. The most effective quaternary ammonium polymers kills 99.9% of both gram negative and gram positive bacteria and the best aldehyde coating kills 81% of the spores on its surface.

  17. The Structure of the Silumin Coat on Alloy Cast Steels

    Directory of Open Access Journals (Sweden)

    T. Szymczak

    2012-04-01

    Full Text Available The work presents the analysis results of the structure of the coat obtained by dipping in silumin AlSi5 of two grades of alloy cast steel: GX6CrNiTi18-10 (LH18N9T and GX39Cr13 (LH14. The temperature of the silumin bath was 750±5°C, and the hold-up time of the cast steel element τ = 180 s. The absolute thickness of the coat obtained in the given conditions was g = 104 μm on cast steel GX6CrNiTi18-10 and g = 132 μm on GX39Cr13. The obtained coat consisted of three layers of different phase structure. The first layer from the base “g1`” was constructed of the phase AlFe including Si and alloy additives of the tested cast steel grades: Cr and Ni (GX6CrNiTi18-10 and Cr (GX39Cr13. The second layer “g1``” of intermetallic phases AlFe which also contains Si and Cr crystallizes on it. The last, external layer “g2” of the coat consists of the silumin containing the intermetallic phases AlFeSi which additionally can contain alloy additives of the cast steel. It was shown that there were no carbides on the coat of the tested cast steels which are the component of their microstructure, as it took place in the case of the coat on the high speed steels.

  18. Coated Aerogel Beads

    Science.gov (United States)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2014-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  19. Anticorrosive coatings: a review

    DEFF Research Database (Denmark)

    Sørensen, Per Aggerholm; Kiil, Søren; Dam-Johansen, Kim

    2009-01-01

    of volatile organic compounds (VOCs) have caused significant changes in the anticorrosive coating industry. The requirement for new VOC-compliant coating technologies means that coating manufacturers can no longer rely on the extensive track record of their time-served products to convince consumers...... of their suitability for use. An important aspect in the development of new VOC-compliant, high-performance anticorrosive coating systems is a thorough knowledge of the components in anticorrosive coatings, their interactions, their advantages and limitations, as well as a detailed knowledge on the failure modes......, and inhibitive coatings are outlined. In the past decades, several alternatives to organic solvent-borne coatings have reached the commercial market. This review also presents some of these technologies and discusses some of their advantages and limitations. Finally, some of the mechanisms leading to degradation...

  20. Pixelated coatings and advanced IR coatings

    Science.gov (United States)

    Pradal, Fabien; Portier, Benjamin; Oussalah, Meihdi; Leplan, Hervé

    2017-09-01

    Reosc developed pixelated infrared coatings on detector. Reosc manufactured thick pixelated multilayer stacks on IR-focal plane arrays for bi-spectral imaging systems, demonstrating high filter performance, low crosstalk, and no deterioration of the device sensitivities. More recently, a 5-pixel filter matrix was designed and fabricated. Recent developments in pixelated coatings, shows that high performance infrared filters can be coated directly on detector for multispectral imaging. Next generation space instrument can benefit from this technology to reduce their weight and consumptions.

  1. Combustion chemical vapor desposited coatings for thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hampikian, J.M.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States)

    1995-10-01

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings.

  2. Characterization of Cr-O cermet solar selective coatings deposited by using direct-current magnetron sputtering technology

    International Nuclear Information System (INIS)

    Lee, Kil Dong

    2006-01-01

    Cr-O (Cr-CrO) cermet solar selective coatings with a double cermet layer film structure were prepared by using a special direct-current (dc) magnetron sputtering technology. The typical film structure from the surface to the bottom substrate was an Al 2 O 3 anti-reflection layer on a double Cr-O cermet layer on an Al metal infrared reflection layer. The deposited Cr-O cermet solar selective coating had an absorptance of α = 0.93 - 0.95 and an emittance of ε = 0.09 - 0.10(100 .deg. C). The absorption layers of the Cr-O cermet coatings deposited on glass and silicon substrates were identified as being amorphous by using X-ray diffraction (XRD). Atomic force microscopy (AFM) showed that Cr-O cermet layers were very smooth and that their grain sizes were very small. The result of thermal stability test showed that the Cr-O cermet solar selective coating was stable for use at temperatures of under 400 .deg. C.

  3. Zr-ZrO sub 2 cermet solar coatings designed by modelling calculations and deposited by dc magnetron sputtering

    CERN Document Server

    Zhang Qi Chu; Lee, K D; Shen, Y G

    2003-01-01

    High solar performance Zr-ZrO sub 2 cermet solar coatings were designed using a numerical computer model and deposited experimentally. The layer thickness and Zr metal volume fraction for the Zr-ZrO sub 2 cermet solar selective coatings on a Zr or Al reflector with a surface ZrO sub 2 or Al sub 2 O sub 3 anti-reflection layer were optimized to achieve maximum photo-thermal conversion efficiency at 80 deg. C under concentration factors of 1-20 using the downhill simplex method in multi-dimensions in the numerical calculation. The dielectric function and the complex refractive index of Zr-ZrO sub 2 cermet materials were calculated using Sheng's approximation. Optimization calculations show that Al sub 2 O sub 3 /Zr-ZrO sub 2 /Al solar coatings with two cermet layers and three cermet layers have nearly identical solar absorptance, emittance and photo-thermal conversion efficiency that are much better than those for films with one cermet layer. The optimized Al sub 2 O sub 3 /Zr-ZrO sub 2 /Al solar coating film w...

  4. The three layers of adaptation granularity

    NARCIS (Netherlands)

    Cristea, A.I.; Calvi, L.; Brusilovsky, P.; Corbett, A.; Rosis, de F.

    2003-01-01

    In spite of the interest in AHS, there are not as many applications as could be expected. We have previously pinpointed the problem to rely on the difficulty of AHS authoring. Adaptive features that have been successfully introduced and implemented until now are often too fine grained, and an author

  5. Development of technique for AR coating and nickel and copper metallization of solar cells. FPS Project: Product development

    Science.gov (United States)

    Taylor, W.

    1982-01-01

    Printed nickel overplated with copper and applied on top of a predeposited silicon nitride antireflective coating system for metallizing solar cells was analyzed. The ESL D and E paste formulations, and the new formulations F, G, H, and D-1 were evaluated. The nickel thick films were tested after firing for stability in the cleaning and plating solutions used in the Vanguard-Pacific brush plating process. It was found that the films are very sensitive to the leaning and alkaline copper solutions. Less sensitivity was displayed to the neutral copper solution. Microscopic and SEM observations show segregation of frit at the silicon nitride thick film interface with loose frit residues after lifting off plated grid lines.

  6. Preliminary coating design and coating developments for ATHENA

    DEFF Research Database (Denmark)

    Jakobsen, Anders Clemen; Ferreira, Desiree Della Monica; Christensen, Finn Erland

    2011-01-01

    We present initial novel coating design for ATHENA. We make use of both simple bilayer coatings of Ir and B4C and more complex constant period multilayer coatings to enhance the effective area and cover the energy range from 0.1 to 10 keV. We also present the coating technology used...... for these designs and present test results from coatings....

  7. Plasma sprayed thermoregulating coatings

    International Nuclear Information System (INIS)

    Kudinov, V.V.; Puzanov, A.A.; Zambrzhitskij, A.P.; Soboleva, V.V.

    1979-01-01

    Shown is the possibility of plasma spraying application for thermoregulating coating formation. Given are test results of service properties of BeO, Al 2 O 2 plasma coatings on the substrates of the MA2-1 magnesium alloy. Described is a device for studying durability of coating optical parameters under ultraviolet irradiation in deep vacuum. Dynamics of absorption coefficient, growth caused by an increase in absorption centers amount under such irradiation is investigated

  8. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  9. Silica coatings on clarithromycin.

    Science.gov (United States)

    Bele, Marjan; Dmitrasinovic, Dorde; Planinsek, Odon; Salobir, Mateja; Srcic, Stane; Gaberscek, Miran; Jamnik, Janko

    2005-03-03

    Pre-crystallized clarithromycin (6-O-methylerythromycin A) particles were coated with silica from the tetraethyl orthosilicate (TEOS)-ethanol-aqueous ammonia system. The coatings had a typical thickness of 100-150 nm and presented about 15 wt.% of the silica-drug composite material. The properties of the coatings depended on reactant concentration, temperature and mixing rate and, in particular, on the presence of a cationic surfactant (cetylpyridinium chloride). In the presence of cetylpyridinium chloride the silica coatings slightly decreased the rate of pure clarithromycin dissolution.

  10. Optimization of Heat Transfer on Thermal Barrier Coated Gas Turbine Blade

    Science.gov (United States)

    Aabid, Abdul; Khan, S. A.

    2018-05-01

    In the field of Aerospace Propulsion technology, material required to resist the maximum temperature. In this paper, using thermal barrier coatings (TBCs) method in gas turbine blade is used to protect hot section component from high-temperature effect to extend the service life and reduce the maintenance costs. The TBCs which include three layers of coating corresponding initial coat is super alloy-INCONEL 718 with 1 mm thickness, bond coat is Nano-structured ceramic-metallic composite-NiCoCrAIY with 0.15 mm thickness and top coat is ceramic composite-La2Ce2O7 with 0.09 mm thickness on the nickel alloy turbine blade which in turn increases the strength, efficiency and life span of the blades. Modeling a gas turbine blade using CATIA software and determining the amount of heat transfer on thermal barrier coated blade using ANSYS software has been performed. Thermal stresses and effects of different TBCs blade base alloys are considered using CATIA and ANSYS.

  11. Study of the mechanical properties of single- layer and multi-layer metallic coatings with protective-decorative applications

    Directory of Open Access Journals (Sweden)

    Cherneva Sabina

    2018-01-01

    Full Text Available Single thin coating of matt nickel (Nimat, a mirror bright copper (Cubright, a mirror bright nickel (Nibright and their combinations were electrochemically deposited on brass substrate with thickness 500 μm. The basic aim was electrodeposition of two-layer Cubright/Nimat and Nibright/Cubright systems, and three-layer Nibright Cubrigh/Nimat system, which are among the most widely applied protective and decorative systems in light and medium operating conditions of corrosion. The thicknesses of the obtained films varied from 1 μm to 3.25 μm. They were investigated via nanoindentation experiments, in order to characterize their basic physical and mechanical characteristics, related with their good adhesion and corrosion protective ability, as well as ensuring the integrity of the system “protective coating/substrate” to possible mechanical, dynamic and/or thermal stresses. As a result, load-displacement curves were obtained and indentation hardness and indentation modulus were calculated using the Oliver & Pharr approximation method. The dependence of the indentation modulus and the indentation hardness on the depth of the indentation, surface morphology and structure of the obtained coatings, their texture and surface roughness were investigated too. The obtained results showed that the three-layer Nibright/Cubright /Niimat/CuZn37 system has highest indentation modulus and indentation hardness, following by two-layer Nibright/Cubright system and single layer coatings.

  12. Preparation of composite micro/nano structure on the silicon surface by reactive ion etching: Enhanced anti-reflective and hydrophobic properties

    Science.gov (United States)

    Zeng, Yu; Fan, Xiaoli; Chen, Jiajia; He, Siyu; Yi, Zao; Ye, Xin; Yi, Yougen

    2018-05-01

    A silicon substrate with micro-pyramid structure (black silicon) is prepared by wet chemical etching and then subjected to reactive ion etching (RIE) in the mixed gas condition of SF6, CHF3 and He. We systematically study the impacts of flow rates of SF6, CHF3 and He, the etching pressure and the etching time on the surface morphology and reflectivity through various characterizations. Meanwhile, we explore and obtain the optimal combination of parameters for the preparation of composite structure that match the RIE process based on the basis of micro-pyramid silicon substrate. The composite sample prepared under the optimum parameters exhibits excellent anti-reflective performance, hydrophobic, self-cleaning and anti-corrosive properties. Based on the above characteristics, the composite micro/nano structure can be applied to solar cells, photodetectors, LEDs, outdoor devices and other important fields.

  13. Fabrication of p-n heterostructure ZnO/Si moth-eye structures: Antireflection, enhanced charge separation and photocatalytic properties

    Science.gov (United States)

    Zeng, Yu; Chen, XiFang; Yi, Zao; Yi, Yougen; Xu, Xibin

    2018-05-01

    The pyramidal silicon substrate is formed by wet etching, then ZnO nanorods are grown on the surface of the pyramidal microstructure by a hydrothermal method to form a moth-eye composite heterostructure. The composite heterostructure of this material determines its excellent anti-reflection properties and ability to absorb light from all angles. In addition, due to the effective heterojunction binding area, the composite micro/nano structure has excellent photoelectric conversion performance. Its surface structure and the large specific surface area gives the material super hydrophilicity, excellent gas sensing characteristic, and photocatalytic properties. Based on the above characteristics, the micro/nano heterostructure can be used in solar cells, sensors, light-emitting devices, and photocatalytic fields.

  14. Integrating anti-reflection and superhydrophobicity of moth-eye-like surface morphology on a large-area flexible substrate

    International Nuclear Information System (INIS)

    Liu, Chia-Hsing; Niu, Pei-Lun; Sung, Cheng-Kuo

    2014-01-01

    This paper proposes an ultraviolet nanoimprint lithography (UV-NIL) roll-to-roll (R2R) process with argon and oxygen (Ar–O 2 ) plasma ashing and coating of a dilute perfluorodecyltrichlorosilane (FDTS) layer to fabricate the large-area moth-eye-like surface morphology on a polyethylene terephthalate substrate. By using Maxwell-Garnett's effective medium theory, the optimal dimensions of the moth-eye-like surface morphology was designed and fabricated with UV-NIL R2R process to obtain maximum transmittance ratio. In addition, the base angle (θ = 30.1°) of the moth-eye-like surface morphology was modified with Ar–O 2 plasma ashing and coated with a dilute FDTS layer to possess both superhydrophobic and air-retention properties. This increases both the transmittance ratio of 4% and contact angle to 153°. (paper)

  15. Superhydrophobic silica coating by dip coating method

    International Nuclear Information System (INIS)

    Mahadik, Satish A.; Parale, Vinayak; Vhatkara, Rajiv S.; Mahadik, Dinesh B.; Kavale, Mahendra S.; Wagh, Pratap B.; Gupta, Satish; Gurav, Jyoti

    2013-01-01

    Herein, we report a simple and low cost method for the fabrication of superhydrophobic coating surface on quartz substrates via sol-gel dip coating method at room temperature. Desired surface chemistry and texture growth for superhydrophobicity developed under double step sol–gel process at room temperature. The resultant superhydrophobic surfaces were characterized by Field-emission scanning electron microscopy (FE-SEM), Atomic force microscopy (AFM), water contact angle (WCA) measurement, differential thermal gravimetric analysis-differential thermal analysis (TGA-DTA) calorimetry and optical spectrometer. Coating shows the ultra high water contact angle about 168 ± 2° and water sliding angle 3 ± 1° and superoleophilic with petroleum oils. This approach allows a simple strategy for the fabrication process of superhydrophilic–superhydrophobic on same surfaces with high thermal stability of superhydrophobicity up to 560 °C. Thus, durability, special wettability and thermal stability of superhydrophobicity expand their application fields.

  16. Coated electroactive materials

    Science.gov (United States)

    Amine, Khalil; Abouimrane, Ali

    2016-08-30

    A process includes suspending an electroactive material in a solvent, suspending or dissolving a carbon precursor in the solvent; and depositing the carbon precursor on the electroactive material to form a carbon-coated electroactive material. Compositions include a graphene-coated electroactive material prepared from a solution phase mixture or suspension of an electroactive material and graphene, graphene oxide, or a mixture thereof.

  17. Rock-hard coatings

    OpenAIRE

    Muller, M.

    2007-01-01

    Aircraft jet engines have to be able to withstand infernal conditions. Extreme heat and bitter cold tax coatings to the limit. Materials expert Dr Ir. Wim Sloof fits atoms together to develop rock-hard coatings. The latest invention in this field is known as ceramic matrix composites. Sloof has signed an agreement with a number of parties to investigate this material further.

  18. Metallurgical coating system

    International Nuclear Information System (INIS)

    Daniels, L.C.; Whittaker, G.S.

    1984-01-01

    The present invention relates to a novel metallurgical coating system which provides corrosion resistance and non-stick properties to metallic components which are subjected to unusually severe operating conditions. The coating system comprises a first layer comprising tantalum which is deposited upon a substrate and a second layer comprising molybdenum disilicide which is deposited upon the first layer

  19. Rock-hard coatings

    NARCIS (Netherlands)

    Muller, M.

    2007-01-01

    Aircraft jet engines have to be able to withstand infernal conditions. Extreme heat and bitter cold tax coatings to the limit. Materials expert Dr Ir. Wim Sloof fits atoms together to develop rock-hard coatings. The latest invention in this field is known as ceramic matrix composites. Sloof has

  20. Unobtrusive graphene coatings

    NARCIS (Netherlands)

    Mugele, Friedrich Gunther

    2012-01-01

    The contact angle of water drops on substrates for which the wettability is dominated by van der Waals forces remains unchanged when the substrates are coated with a monolayer of graphene. Such 'wetting transparency' could lead to superior conducting and hydrophobic graphene-coated surfaces with

  1. Coating thickness measurement

    International Nuclear Information System (INIS)

    1976-12-01

    The standard specifies measurements of the coating thickness, which make use of beta backscattering and/or x-ray fluorescence. For commonly used combinations of coating material and base material the appropriate measuring ranges and radionuclides to be used are given for continuous as well as for discontinuous measurements

  2. Duplex aluminized coatings

    Science.gov (United States)

    Gedwill, M. A.; Grisaffe, S. J. (Inventor)

    1975-01-01

    The surface of a metallic base system is initially coated with a metallic alloy layer that is ductile and oxidation resistant. An aluminide coating is then applied to the metallic alloy layer. The chemistry of the metallic alloy layer is such that the oxidation resistance of the subsequently aluminized outermost layer is not seriously degraded.

  3. Coated ceramic breeder materials

    Science.gov (United States)

    Tam, Shiu-Wing; Johnson, Carl E.

    1987-01-01

    A breeder material for use in a breeder blanket of a nuclear reactor is disclosed. The breeder material comprises a core material of lithium containing ceramic particles which has been coated with a neutron multiplier such as Be or BeO, which coating has a higher thermal conductivity than the core material.

  4. High performance W-AIN cermet solar coatings designed by modelling calculations and deposited by DC magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Qi-Chu Zhang [The University of Sydney (Australia). School of Physics; Shen, Y.G. [City University of Hong Kong (Hong Kong). Department of Manufacturing Engineering and Engineering Management

    2004-01-25

    High solar performance W-AIN cermet solar coatings were designed using a numerical computer model and deposited experimentally. In the numerical calculations aluminium oxynitride (AlON) was used as ceramic component. The dielectric functions and then complex refractive index of W-AlON cermet materials were calculated using the Sheng's approximation. The layer thickness and W metal volume fraction were optimised to achieve maximum photo-thermal conversion efficiency for W-AlON cermet solar coatings on an Al reflector with a surface AlON ceramic anti-reflection layer. Optimisation calculations show that the W-AlON cermet solar coatings with two and three cermet layers have nearly identical solar absorptance, emittance and photo-thermal conversion efficiency that are much better than those for films with one cermet layer. The optimised calculated AlON/W-AlON/Al solar coating film with two cermet layers has a high solar absorptance of 0.953 and a low hemispherical emittance of 0.051 at 80{sup o}C for a concentration factor of 2. The AlN/W-AlN/Al solar selective coatings with two cermet layers were deposited using two metal target direct current magnetron sputtering technology. During the deposition of W-AlN cermet layer, both Al and W targets were run simultaneously in a gas mixture of argon and nitrogen. By substrate rotation a multi-sub-layer system consisting of alternating AlN ceramic and W metallic sub-layers was deposited that can be considered as a macro-homogeneous W-AlN cermet layer. A solar absorptance of 0.955 and nearly normal emittance of 0.056 at 80{sup o}C have been achieved for deposited W-AlN cermet solar coatings. (author)

  5. High performance W-AlN cermet solar coatings designed by modelling calculations and deposited by DC magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qi-Chu [School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia); Shen, Y.G. [Department of Manufacturing Engineering and Engineering Management, City University of Hong Kong (Hong Kong)

    2004-01-25

    High solar performance W-AlN cermet solar coatings were designed using a numerical computer model and deposited experimentally. In the numerical calculations aluminium oxynitride (AlON) was used as ceramic component. The dielectric function and then complex refractive index of W-AlON cermet materials were calculated using the Sheng's approximation. The layer thickness and W metal volume fraction were optimised to achieve maximum photo-thermal conversion efficiency for W-AlON cermet solar coatings on an Al reflector with a surface AlON ceramic anti-reflection layer. Optimisation calculations show that the W-AlON cermet solar coatings with two and three cermet layers have nearly identical solar absorptance, emittance and photo-thermal conversion efficiency that are much better than those for films with one cermet layer. The optimised calculated AlON/W-AlON/Al solar coating film with two cermet layers has a high solar absorptance of 0.953 and a low hemispherical emittance of 0.051 at 80C for a concentration factor of 2. The AlN/W-AlN/Al solar selective coatings with two cermet layers were deposited using two metal target direct current magnetron sputtering technology. During the deposition of W-AlN cermet layer, both Al and W targets were run simultaneously in a gas mixture of argon and nitrogen. By substrate rotation a multi-sub-layer system consisting of alternating AlN ceramic and W metallic sub-layers was deposited that can be considered as a macro-homogeneous W-AlN cermet layer. A solar absorptance of 0.955 and nearly normal emittance of 0.056 at 80C have been achieved for deposited W-AlN cermet solar coatings.

  6. Radiation curable coating compositions

    International Nuclear Information System (INIS)

    Jenkinson, R.D.; Carder, C.H.

    1979-01-01

    The present invention provides a low-toxicity diluent component for radiation curable coating compositions that contain an acrylyl or methacryly oligomer or resin component such as an acrylyl urethane oligomer. The low-toxicity diluent component of this invention is chosen from the group consisting of tetraethlorthosilicate and tetraethoxyethylorthosilicate. When the diluent component is used as described, benefits in addition to viscosity reduction, may be realized. Application characteristics of the uncured coatings composition, such as flowability, leveling, and smoothness are notably improved. Upon curing by exposure to actinic radiation, the coating composition forms a solid, non-tacky surface free of pits, fissures or other irregularities. While there is no readily apparent reactive mechanism by which the orthosilicate becomes chemically bonded to the cured coating, the presence of silicon in the cured coating has been confirmed by scanning electron microscopy. 12 drawing

  7. Charged-particle coating

    International Nuclear Information System (INIS)

    Johnson, W.L.; Crane, J.K.; Hendricks, C.D.

    1980-01-01

    Advanced target designs require thicker (approx. 300 μm) coatings and better surface finishes that can be produced with current coating techniques. An advanced coating technique is proposed to provide maximum control of the coating flux and optimum manipulation of the shell during processing. In this scheme a small beam of ions or particles of known incident energy are collided with a levitated spherical mandrel. Precise control of the incident energy and angle of the deposition flux optimizes the control of the coating morphology while controlled rotation and noncontact support of the shell minimizes the possibility of particulate or damage generated defects. Almost infinite variability of the incident energy and material in this process provides increased flexibility of the target designs which can be physically realized

  8. Coating thickness measuring device

    International Nuclear Information System (INIS)

    Joffe, B.B.; Sawyer, B.E.; Spongr, J.J.

    1984-01-01

    A device especially adapted for measuring the thickness of coatings on small, complexly-shaped parts, such as, for example, electronic connectors, electronic contacts, or the like. The device includes a source of beta radiation and a radiation detector whereby backscatter of the radiation from the coated part can be detected and the thickness of the coating ascertained. The radiation source and detector are positioned in overlying relationship to the coated part and a microscope is provided to accurately position the device with respect to the part. Means are provided to control the rate of descent of the radiation source and radiation detector from its suspended position to its operating position and the resulting impact it makes with the coated part to thereby promote uniformity of readings from operator to operator, and also to avoid excessive impact with the part, thereby improving accuracy of measurement and eliminating damage to the parts

  9. POSS(Registered TradeMark) Coatings for Solar Cells: An Update

    Science.gov (United States)

    Brandhorst, Henry; Isaacs-Smith, Tamara; Wells, Brian; Lichtenhan, Joseph D.; Fu, Bruce X.

    2007-01-01

    Presently, solar cells are covered with Ce-doped microsheet cover glasses that are attached with Dow Corning DC 93-500 silicone adhesive. Various antireflection coatings are often applied to the cover glass to increase cell performance. This general approach has been used from the beginning of space exploration. However, it is expensive and time consuming. Furthermore, as the voltage of solar arrays increases, significant arcing has occurred in solar arrays, leading to loss of satellite power. The cause has been traced to differential voltages between strings and the close spacing between them with no insulation covering the edges of the solar cells. In addition, this problem could be ameliorated if the cover glass extended over the edges of the cell, but this would impact packing density. An alternative idea that might solve all these issues and be less expensive and more protective is to develop a coating that could be applied over the entire array. Such a coating must be resistant to atomic oxygen for low earth orbits below about 700 km, it must be resistant to ultraviolet radiation for all earth and near-sun orbits and, of course, it must withstand the damaging effects of space radiation. Coating flexibility would be an additional advantage. Based on past experience, one material that has many of the desired attributes of a universal protective coating is the Dow Corning DC 93-500. Of all the potential optical plastics, it appears to be the most suitable for use in space. As noted above, DC 93-500 has been extensively used to attach cover glasses to crystalline solar cells and has worked exceptionally well over the years. It is flexible and generally resistant to electrons, protons and ultraviolet (UV and VUV) radiation; although a VUV-rejection coating or VUV-absorbing ceria-doped cover glass may be required for long mission durations. It can also be applied in a thin coating (< 25 m) by conventional liquid coating processes. Unfortunately, when exposed to

  10. Effect of SiO{sub 2} coating in bolometric Ge light detectors for rare event searches

    Energy Technology Data Exchange (ETDEWEB)

    Beeman, J.W. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gentils, A. [Centre de Spectrométrie Nuclaire et de Spectrométrie de Masse, CNRS and Université Paris-Sud, F-91405 Orsay (France); Giuliani, A., E-mail: andrea.giuliani@csnsm.in2p3.fr [Centre de Spectrométrie Nuclaire et de Spectrométrie de Masse, CNRS and Université Paris-Sud, F-91405 Orsay (France); Università dell' Insubria, Dipartimento di Scienza e Alta Tecnologia, 22100 Como, Italy, (Italy); INFN, Sezione di Milano Bicocca, 20126 Milano (Italy); Mancuso, M. [Università dell' Insubria, Dipartimento di Scienza e Alta Tecnologia, 22100 Como, Italy, (Italy); INFN, Sezione di Milano Bicocca, 20126 Milano (Italy); Pessina, G. [Università di Milano-Bicocca, Dipartimento di Fisica, and INFN, Sezione di Milano Bicocca, 20126 Milano (Italy); Plantevin, O. [Centre de Spectrométrie Nuclaire et de Spectrométrie de Masse, CNRS and Université Paris-Sud, F-91405 Orsay (France); Rusconi, C. [Università dell' Insubria, Dipartimento di Scienza e Alta Tecnologia, 22100 Como, Italy, (Italy); INFN, Sezione di Milano Bicocca, 20126 Milano (Italy)

    2013-05-01

    In germanium-based light detectors for scintillating bolometers, a SiO{sub 2} anti-reflective coating is often applied on the side of the germanium wafer exposed to light with the aim to improve its light collection efficiency. In this paper, we report about a measurement, performed in the temperature range 25–35 mK, of the light-collection increase obtained thanks to this method, which resulted to be of the order of 20%. The procedure followed has been carefully selected in order to minimize systematic effects. The employed light sources have the same spectral features (peaking at ∼630nm wavelength) that will characterize future neutrinoless double beta decay experiments on the isotope {sup 82}Se and based on ZnSe crystals, such as LUCIFER. The coupling between source and light detector reproduces the configuration used in scintillating bolometers. The present measurement clarifies the role of SiO{sub 2} coating and describes a method and a set-up that can be extended to the study of other types of coatings and luminescent materials.

  11. Coatings to prevent frost

    DEFF Research Database (Denmark)

    Lusada, Ricardo; Holberg, Stefan; Bennedsen, Jeanette Marianne Dalgaard

    2016-01-01

    The ability of hydrophobic, organic–inorganic hybrid coatings to decelerate frost propagation was investigated. Compared to a bare aluminum surface, the coatings do not significantly reduce the freezing probability of supercooled water drops. On both surfaces, the probability for ice nucleation...... at temperatures just below 0°C, for example at −4°C, is low. Freezing of a single drop on aluminum leads, however, to instant freezing of the complete surface. On hydrophobic coatings, such a freezing drop is isolated; the frozen area grows slowly. At −4°C surface temperature in a +12°C/90% relative humidity...

  12. Effect of Thickness on the Morphology and Corrosion Behavior of Cerium-Based Conversion Coatings on AZ31B Magnesium Alloy

    Science.gov (United States)

    Castano, Carlos E.; Maddela, Surender; O'Keefe, Matthew J.; Wang, Yar-Ming

    Cerium-based conversion coatings (CeCCs) were deposited onto AZ31B magnesium alloy substrates using a spontaneous reaction of CeCl3, H2O2 and gelatin in a water-based solution. The coating thickness was adjusted by controlling the immersion time in the deposition solution. Prior to deposition, the AZ31B substrates were treated using an acid pickling in nitric acid and then an alkaline cleaning in sodium metasilicate pentahydrate. After deposition, the coated samples were immersed in a phosphate bath that converted cerium oxide/hydroxide into cerium phosphate. Electrochemical impedance spectroscopy, potentiodynamic polarization and neutral salt spray testing studies indicated that 100 nm thick CeCC had better corrosion performance than 400 nm coatings. Characterization of the CeCCs by transmission electron microscopy (TEM) revealed a three layer structure with different compositions.

  13. Thermally joining and/or coating or thermally separating the workpieces having heat-sensitive coating, comprises restoring coating by thermally coating the coating material after thermally joining and/or coating or thermally separating

    OpenAIRE

    Riedel, Frank; Winkelmann, Ralf; Puschmann, Markus

    2011-01-01

    The method for thermally joining and/or coating or thermally separating the workpieces (1), which have a heat-sensitive coating (2), comprises restoring the coating by thermally coating a coating material (3) after thermally joining and/or coating or thermally separating the workpieces. A part of the thermal energy introduced in the workpiece for joining and/or coating or separating or in the workpieces is used for thermally coating the coating material. Two workpieces are welded or soldered ...

  14. POWDER COAT APPLICATIONS

    Science.gov (United States)

    The report discusses an investigation of critical factors that affect the use of powder coatings on the environment, cost, quality, and production. The investigation involved a small business representative working with the National Defense Center for Environmental Excellence (ND...

  15. Inorganic Coatings Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The inorganic Coatings Lab provides expertise to Navy and Joint Service platforms acquisition IPTs to aid in materials and processing choices which balance up-front...

  16. Robust Fiber Coatings

    National Research Council Canada - National Science Library

    Goettler, Richard

    2002-01-01

    The highly desired ceramic matrix composite is the one in which the high strength and strain-to-failure is achieved through judicious selection of a fiber coating that can survive the high-temperature...

  17. Coating of substrates

    International Nuclear Information System (INIS)

    Cairns, J.A.; Nelson, R.L.; Woodhead, J.L.

    1979-01-01

    The process is concerned with providing substrates with coatings obtainable from sols, for example to protect the substrate (such as in nuclear reactors or hydrocarbon cracking plant) or to provide a carrier for catalytically active material. Hitherto, coatings obtained from sols have had a high porosity and high surface area so that they have not been entirely satisfactory for the above applications. In the process described, dense, low-porosity coatings are provided by contacting the substrate with a sol of refractory material (e.g. CeO 2 or SiO 2 ) convertible to a gel of density at least 40% of the theoretical density of the refractory material, and converting the sol to the gel. Optionally, the gel may be converted to a ceramic coating by firing. (author)

  18. Friction surfaced Stellite6 coatings

    International Nuclear Information System (INIS)

    Rao, K. Prasad; Damodaram, R.; Rafi, H. Khalid; Ram, G.D. Janaki; Reddy, G. Madhusudhan; Nagalakshmi, R.

    2012-01-01

    Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: ► Stellite6 used as coating material for friction surfacing. ► Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. ► Finer and uniformly distributed carbides in friction surfaced coatings. ► Absence of melting results compositional homogeneity in FS Stellite6 coatings.

  19. Radiation hardening coating material

    International Nuclear Information System (INIS)

    McDonald, W.H.; Prucnal, P.J.; DeMajistre, Robert.

    1977-01-01

    This invention concerns a radiation hardening coating material. First a resin is prepared by reaction of bisphenol diglycidylic ether with acrylic or methacrylic acids. Then the reactive solvent is prepared by reaction of acrylic or methacrylic acids with epichlorhydrine or epibromhydrine. Then a solution consisting of the resin dissolved in the reactive solvent is prepared. A substrate (wood, paper, polyesters, polyamines etc.) is coated with this composition and exposed to ionizing radiations (electron beams) or ultraviolet radiations [fr

  20. Hydroxyapatite coatings for biomedical applications

    CERN Document Server

    Zhang, Sam

    2013-01-01

    Hydroxyapatite coatings are of great importance in the biological and biomedical coatings fields, especially in the current era of nanotechnology and bioapplications. With a bonelike structure that promotes osseointegration, hydroxyapatite coating can be applied to otherwise bioinactive implants to make their surface bioactive, thus achieving faster healing and recovery. In addition to applications in orthopedic and dental implants, this coating can also be used in drug delivery. Hydroxyapatite Coatings for Biomedical Applications explores developments in the processing and property characteri

  1. 三层网络监控的新型煤矿井下电力安全监控系统研究%Three layer of network monitoring of new coal mine underground power safety monitoring system research

    Institute of Scientific and Technical Information of China (English)

    伍龙; 吴永祥; 周孟然

    2011-01-01

    利用嵌入式监控分站作为中继站,智能电力装置面向现场设备进行实时数据采集,结合地面微机管理系统,形成了三层网络监控的新型煤矿井下电力安全监控系统。介绍了系统硬件设计,并完成了系统软件设计和测试,结果表明:监控系统运行正常、动作可靠、灵敏度高、显示正确无误、各项指标均达到了设计要求,实现了三级网络整定保护定值和远程监控,提高了煤矿井下电力安全监控系统的实时数据处理能力。%Use embedded monitoring RACES as Repeaters,intelligent power device for on-site equipment real-time data acquisition,micro-processor management on the ground,formed three layer of network monitoring of new coal mine underground power safety monitoring system.This paper introduces the hardware design,and completed the system software design and test,the result shows that the monitoring system operating normally,reliable operation,high sensitivity,display correct,all indexes meet the design requirements,improve the power safety monitoring system coal mine underground real-time data processing ability.

  2. Biocompatibility of Niobium Coatings

    Directory of Open Access Journals (Sweden)

    René Olivares-Navarrete

    2011-09-01

    Full Text Available Niobium coatings deposited by magnetron sputtering were evaluated as a possible surface modification for stainless steel (SS substrates in biomedical implants. The Nb coatings were deposited on 15 mm diameter stainless steel substrates having an average surface roughness of 2 mm. To evaluate the biocompatibility of the coatings three different in vitro tests, using human alveolar bone derived cells, were performed: cellular adhesion, proliferation and viability. Stainless steel substrates and tissue culture plastic were also studied, in order to give comparative information. No toxic response was observed for any of the surfaces, indicating that the Nb coatings act as a biocompatible, bioinert material. Cell morphology was also studied by immune-fluorescence and the results confirmed the healthy state of the cells on the Nb surface. X-ray diffraction analysis of the coating shows that the film is polycrystalline with a body centered cubic structure. The surface composition and corrosion resistance of both the substrate and the Nb coating were also studied by X-ray photoelectron spectroscopy and potentiodynamic tests. Water contact angle measurements showed that the Nb surface is more hydrophobic than the SS substrate.

  3. Coated particle waste form development

    International Nuclear Information System (INIS)

    Oma, K.H.; Buckwalter, C.Q.; Chick, L.A.

    1981-12-01

    Coated particle waste forms have been developed as part of the multibarrier concept at Pacific Northwest Laboratory under the Alternative Waste Forms Program for the Department of Energy. Primary efforts were to coat simulated nuclear waste glass marbles and ceramic pellets with low-temperature pyrolytic carbon (LT-PyC) coatings via the process of chemical vapor deposition (CVD). Fluidized bed (FB) coaters, screw agitated coaters (SAC), and rotating tube coaters were used. Coating temperatures were reduced by using catalysts and plasma activation. In general, the LT-PyC coatings did not provide the expected high leach resistance as previously measured for carbon alone. The coatings were friable and often spalled off the substrate. A totally different concept, thermal spray coating, was investigated at PNL as an alternative to CVD coating. Flame spray, wire gun, and plasma gun systems were evaluated using glass, ceramic, and metallic coating materials. Metal plasma spray coatings (Al, Sn, Zn, Pb) provided a two to three orders-of-magnitude increase in chemical durability. Because the aluminum coatings were porous, the superior leach resistance must be due to either a chemical interaction or to a pH buffer effect. Because they are complex, coated waste form processes rank low in process feasibility. Of all the possible coated particle processes, plasma sprayed marbles have the best rating. Carbon coating of pellets by CVD ranked ninth when compared with ten other processes. The plasma-spray-coated marble process ranked sixth out of eleven processes

  4. Improved performance of Mg–Y alloy thin film switchable mirrors after coating with a superhydrophobic surface

    Energy Technology Data Exchange (ETDEWEB)

    La, Mao [Department of Chemistry and Environmental Science, Inner Mongolia Normal University, Hohhot, Inner Mongolia, 010020 (China); State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Zhou, Huaijuan; Li, Ning; Xin, Yunchuan [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Sha, Ren, E-mail: sr@imnu.edu.cn [Department of Chemistry and Environmental Science, Inner Mongolia Normal University, Hohhot, Inner Mongolia, 010020 (China); Bao, Shanhu, E-mail: shanhu.bao@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Jin, Ping [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China)

    2017-05-01

    Highlights: • The PTFE films was prepared for use as the top layer of Mg–Y/Pd switchable mirrors. • The PTFE as an antireflection layer to improve the luminous transmission, and also to enhance the switching durability of the switchable mirrors. • The PTFE film has a superhydrophobic surface, which endows the Mg–Y/Pd switchable mirrors with self-cleaning properties. - Abstract: The magnesium based switchable mirrors can reversibly change their optical properties between the transparent and the reflective state as a result of hydrogenation and dehydrogenation. These films can potentially be applied as new energy-saving windows, by controlling the transmittance of solar radiation through the regulation of their reflective state. In this study, magnesium–yttrium (Mg–Y) alloy thin films were prepared using a DC magnetron sputtering method. However, the luminous transmittance in the transparent state and the switching durability of switchable mirrors are too poor to satisfy practical demands. In order to improve the films switching durability, luminous transmittance and the surface functionalization, polytetrafluoroethylene (PTFE) was coated with thermal vacuum deposition for use as the top layer of Mg–Y/Pd switchable mirrors. The PTFE layer had a porous network structure and exhibited a superhydrophobic surface with a water contact angle of approximately 152°. By characterization, PTFE thin films shows the excellent protection role against the oxidization of Mg, the switching durability of the films were improved 3 times, and also shows the antireflection role the luminous transmission of films was enhanced by 7% through the top covered with PTFE.

  5. Improved performance of Mg–Y alloy thin film switchable mirrors after coating with a superhydrophobic surface

    International Nuclear Information System (INIS)

    La, Mao; Zhou, Huaijuan; Li, Ning; Xin, Yunchuan; Sha, Ren; Bao, Shanhu; Jin, Ping

    2017-01-01

    Highlights: • The PTFE films was prepared for use as the top layer of Mg–Y/Pd switchable mirrors. • The PTFE as an antireflection layer to improve the luminous transmission, and also to enhance the switching durability of the switchable mirrors. • The PTFE film has a superhydrophobic surface, which endows the Mg–Y/Pd switchable mirrors with self-cleaning properties. - Abstract: The magnesium based switchable mirrors can reversibly change their optical properties between the transparent and the reflective state as a result of hydrogenation and dehydrogenation. These films can potentially be applied as new energy-saving windows, by controlling the transmittance of solar radiation through the regulation of their reflective state. In this study, magnesium–yttrium (Mg–Y) alloy thin films were prepared using a DC magnetron sputtering method. However, the luminous transmittance in the transparent state and the switching durability of switchable mirrors are too poor to satisfy practical demands. In order to improve the films switching durability, luminous transmittance and the surface functionalization, polytetrafluoroethylene (PTFE) was coated with thermal vacuum deposition for use as the top layer of Mg–Y/Pd switchable mirrors. The PTFE layer had a porous network structure and exhibited a superhydrophobic surface with a water contact angle of approximately 152°. By characterization, PTFE thin films shows the excellent protection role against the oxidization of Mg, the switching durability of the films were improved 3 times, and also shows the antireflection role the luminous transmission of films was enhanced by 7% through the top covered with PTFE.

  6. Coatings for directional eutectics

    Science.gov (United States)

    Rairden, J. R.; Jackson, M. R.

    1976-01-01

    Coatings developed to provide oxidation protection for the directionally-solidified eutectic alloy NiTaC-B (4.4 weight percent Cr) were evaluated. Of seven Co-, Fe- and Ni-base coatings that were initially investigated, best resistance to cyclic oxidation was demonstrated by duplex coatings fabricated by depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam source followed by deposition of an Al overlayer using the pack cementation process. It was found that addition of carbon to the coating alloy substantially eliminated the problem of fiber denudation in TaC-type eutectic alloys. Burner rig cycled NiTaC-B samples coated with Ni-20Cr-5Al-0.1C-0.1Y+Al and rupture-tested at 1100 deg C performed as well as or better than uncoated, vacuum cycled and air-tested NiTaC-13; however, a slight degradation with respect to uncoated material was noted in air-stress rupture tests at 870 deg C for both cycled and uncycled samples.

  7. The structure of the alphinizing coat on alloy steels

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2008-12-01

    Full Text Available In this paper results of the structure of the coat alphinizing in AlSi5 silumin on alloy steels: acid-proof 1H18N9T (X6CrNiTi18-10 and high speed SW18 (HS18-0-1 were presented. The temperature of the alphinizing bath was amounts to750±5°C, and immersion time of the element τ = 180s. It was shown, that there is the different “g” coat thickness on testing steels. On the 1H18N9T steel it amounts to g = 52μm, and on the SW18 steel – g = 203μm. Regardless of a grade of testing alloy steels the coat consist of three layers with diversified phasic structure. There is different chemical composition of coat layers on testing steels. The first layer from the base consist of AlFe phase containing alloy addictions of steels: Cr and Ni (1H18N9T and W, V and Cr (SW18. On this layer crystallize the second layer of intermetallic phases. It is the phase containing the main alloy addiction of steels: AlFeCr (1H18N9T and AlFeW (SW18. The last, outside layer consist of silumin containing AlFeNi intermetallic phases on the 1H18N9T steel and AlFeW on the SW18 steel. Regardless of the grade of testing steels there is Si element in all layers of the coat. There are morphological differences in tested layers. The second layer (AlFeW phase inside the coat on the SW18 steel consist of faced crystals growing into in outside silumin layer. On the 1H18N9T steel a boundary between transient and outside layer is more uniform. Free separations of intermetallic phases inside silumin layer on the 1H18N9T steel have lamellar and on the SW18 steel – faced form.

  8. Influence of etching process parameters on the antireflection property of Si SWSs by thermally dewetted Ag and Ag/SiO{sub 2} nanopatterns

    Energy Technology Data Exchange (ETDEWEB)

    Leem, Jung Woo; Yu, Jae Su [Department of Electronics and Radio Engineering, Kyung Hee University, 446-701 Yongin (Korea, Republic of); Song, Young Min; Lee, Yong Tak [Department of Information and Communications, Gwangju Institute of Science and Technology, 500-712 Gwangju (Korea, Republic of)

    2011-08-15

    The etching parameter dependent antireflection characteristics of disordered Si subwavelength structures (SWSs) by inductively coupled plasma (ICP) etching in a mixture gas of SiCl{sub 4}/Ar using thermally dewetted Ag and Ag/SiO{sub 2} nanopatterns are investigated. The average size and period of Si SWSs are closely correlated with thermal dewetting conditions. For desirable Ag nanoparticle patterns, the profile of Si SWSs is optimized by changing the ICP etching process parameters to obtain the lowest reflectance spectrum. The most tapered SWS with the highest height leads to a relatively low reflectance. The Ag nanopatterns result in more tapered and rough surface SWSs compared to the Ag/SiO{sub 2} nanopatterns, indicating a slightly reduced reflectance. The Si SWS etched using Ag nanopatterns by SiCl{sub 4}/Ar of 5 sccm/10 sccm at 50 W RF power, 200 W ICP power, and 10 mTorr process pressure exhibits a very low total reflectance of <{proportional_to}2.4% in the wavelength range of 400-1000 nm, maintaining a specular reflectance of <16% at 350-1100 nm up to the incident angle of {theta}{sub i} = 50 . (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. METHOD OF PROTECTIVELY COATING URANIUM

    Science.gov (United States)

    Eubank, L.D.; Boller, E.R.

    1959-02-01

    A method is described for protectively coating uranium with zine comprising cleaning the U for coating by pickling in concentrated HNO/sub 3/, dipping the cleaned U into a bath of molten zinc between 430 to 600 C and containing less than 0 01% each of Fe and Pb, and withdrawing and cooling to solidify the coating. The zinccoated uranium may be given a; econd coating with another metal niore resistant to the corrosive influences particularly concerned. A coating of Pb containing small proportions of Ag or Sn, or Al containing small proportions of Si may be applied over the zinc coatings by dipping in molten baths of these metals.

  10. Zirconium nitride hard coatings

    International Nuclear Information System (INIS)

    Roman, Daiane; Amorim, Cintia Lugnani Gomes de; Soares, Gabriel Vieira; Figueroa, Carlos Alejandro; Baumvol, Israel Jacob Rabin; Basso, Rodrigo Leonardo de Oliveira

    2010-01-01

    Zirconium nitride (ZrN) nanometric films were deposited onto different substrates, in order to study the surface crystalline microstructure and also to investigate the electrochemical behavior to obtain a better composition that minimizes corrosion reactions. The coatings were produced by physical vapor deposition (PVD). The influence of the nitrogen partial pressure, deposition time and temperature over the surface properties was studied. Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and corrosion experiments were performed to characterize the ZrN hard coatings. The ZrN films properties and microstructure changes according to the deposition parameters. The corrosion resistance increases with temperature used in the films deposition. Corrosion tests show that ZrN coating deposited by PVD onto titanium substrate can improve the corrosion resistance. (author)

  11. Fabrication of a Ni nano-imprint stamp for an anti-reflective layer using an anodic aluminum oxide template.

    Science.gov (United States)

    Park, Eun-Mi; Lim, Seung-Kyu; Ra, Senug-Hyun; Suh, Su-Jung

    2013-11-01

    Aluminum anodizing can alter pore diameter, density distribution, periodicity and layer thickness in a controlled way. Because of this property, porous type anodic aluminum oxide (AAO) was used as a template for nano-structure fabrication. The alumina layer generated at a constant voltage increased the pore size from 120 nm to 205 nm according to an increasing process time from 60 min to 150 min. The resulting fabricated AAO templates had pore diameters at or less than 200 nm. Ni was sputtered as a conductive layer onto this AAO template and electroplated using DC and pulse power. Comparing these Ni stamps, those generated from electroplating using on/reverse/off pulsing had an ordered pillar array and maintained the AAO template morphology. This stamp was used for nano-imprinting on UV curable resin coated glass wafer. Surface observations via electron microscopy showed that the nano-imprinted patterned had the same shape as the AAO template. A soft mold was subsequently fabricated and nano-imprinted to form a moth-eye structure on the glass wafer. An analysis of the substrate transmittance using UV-VIS/NIR spectroscopy showed that the transmittance of the substrate with the moth-eye structure was 5% greater that the non-patterned substrate.

  12. Nanophase hardfaced coatings

    Energy Technology Data Exchange (ETDEWEB)

    Reisgen, U.; Stein, L.; Balashov, B.; Geffers, C. [RWTH Aachen University (Germany). ISF - Welding and Joining Institute

    2009-08-15

    This paper demonstrates the possibility of producing iron or chromium-based nanophase hardfaced coatings by means of common arc welding methods (TIG, PTA). The appropriate composition of the alloys to be deposited allows to control the structural properties and thus also the coating properties of the weld metal. Specific variations of the alloying elements allow also the realisation of a nanostructured solidification of the carbides and borides with cooling rates that are common for arc surfacing processes. The hardfaced coatings, which had been thus produced, showed phase dimensions of approximately 100-300 nm. Based on the results it is established that the influence of the surfacing parameters and of the coating thickness and thus the influence of the heat control on the nanostructuring process is, compared with the influence of the alloy composition, of secondary importance. The generation of nanoscale structures in hardfaced coatings allows the improvement of mechanical properties, wear resistance and corrosion resistance. Potential applications for these types of hardfaced coatings lie, in particular, in the field of cutting tools that are exposed to corrosion and wear. (Abstract Copyright [2009], Wiley Periodicals, Inc.) [German] Diese Arbeit demonstriert die Moeglichkeit zur Herstellung Eisen- und Chrom-basierter nanophasiger Hartauftragschweissschichten mithilfe ueblicher Lichtbogenschweissverfahren (WIG-, Plasma-Pulver-Auftragschweissen - PPA). Eine geeignete Zusammensetzung der aufzutragenden Legierungen ermoeglicht es, die Gefuegeeigenschaften und damit die Schichteigenschaften des Schweissgutes zu kontrollieren. Gezielte Variationen der Legierungselemente erlauben die Realisierung einer nanostrukturierten Erstarrung der Karbide und Boride bei fuer Lichtbogen-Auftragschweissprozessen ueblichen Abkuehlgeschwindigkeiten. In den so erzeugten Hartschichten werden Phasengroessen von ca. 100-300 nm erreicht. Auf Basis der gewonnenen Ergebnisse kann

  13. Tribology and coatings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    The future use of fuel-efficient, low-emission, advanced transportation systems (for example, those using low-heat-rejection diesel engines or advanced gas turbines) presents new challenges to tribologists and materials scientists. High service temperatures, corrosive environments, and extreme contact pressures are among the concerns that make necessary new tribological designs, novel materials, and effective lubrication concepts. Argonne is working on methods to reduce friction, wear and corrosion, such as soft metal coatings on ceramics, layered compounds, diamond coatings, and hard surfaces.

  14. Active Packaging Coatings

    Directory of Open Access Journals (Sweden)

    Luis J. Bastarrachea

    2015-11-01

    Full Text Available Active food packaging involves the packaging of foods with materials that provide an enhanced functionality, such as antimicrobial, antioxidant or biocatalytic functions. This can be achieved through the incorporation of active compounds into the matrix of the commonly used packaging materials, or by the application of coatings with the corresponding functionality through surface modification. The latter option offers the advantage of preserving the packaging materials’ bulk properties nearly intact. Herein, different coating technologies like embedding for controlled release, immobilization, layer-by-layer deposition, and photografting are explained and their potential application for active food packaging is explored and discussed.

  15. Mechanically Invisible Polymer Coatings

    DEFF Research Database (Denmark)

    2014-01-01

    phase comprises particles, said particles comprising a filler material and an encapsulating coating of a second polymeric material, wherein the backbones of the first and second polymeric materials are the same. The composition may be used in electroactive polymers (EAPs) in order to obtain mechanically......The present invention relates to a composition comprising encapsulated particles in a polymeric material. The composition comprises a continuous phase and a discontinuous phase incorporated therein, wherein the continuous phase comprises a first polymeric material and wherein the discontinuous...... invisible polymer coatings....

  16. Methods and means for coating paper by film coating

    NARCIS (Netherlands)

    van der Maarel, Marc; Ter Veer, Arend Berend Cornelis; Vrieling-Smit, Annet; Delnoye, Pierre

    2015-01-01

    This invention relates to the field of paper coating, more in particular to means and methods for providing paper with at least one layer of pigment using film coating to obtain a well printable surface. Provided is a method for preparing coated paper comprising the steps of: a) providing a

  17. Raising the shields: PCR in the presence of metallic surfaces protected by tailor-made coatings.

    Science.gov (United States)

    Scherag, Frank D; Brandstetter, Thomas; Rühe, Jürgen

    2014-10-01

    The implementation of PCR reactions in the presence of metallic surfaces is interesting for the generation of novel bioanalytical devices, because metals exhibit high mechanical stability, good thermal conductivity, and flexibility during deformation. However, metallic substrates are usually non-compatible with enzymatic reactions such as PCR due to poisoning of the active center of the enzyme or nonspecific adsorption of the enzymeto the metal surface, which could result in protein denaturation. We present a method for the generation of polymer coatings on metallic surfaces which are designed to minimize protein adsorption and also prevent the release of metal ions. These coatings consist of three layers covalently linked to each other; a self-assembled monolayer to promote adhesion, a photochemically generated barrier layer and a photochemically generated hydrogel. The coatings can be deposited onto aluminum, stainless steel, gold and copper surfaces. We compare PCR efficiencies in the presence of bare metallic surfaces with those of surfaces treated with the novel coating system. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. UV Coatings, Polarization, and Coronagraphy

    Science.gov (United States)

    Bolcar, Matthew R.; Quijada, Manuel; West, Garrett; Balasubramanian, Bala; Krist, John; Martin, Stefan; Sabatke, Derek

    2016-01-01

    Presenation for the Large UltraViolet Optical Infrared (LUVOIR) and Habitable Exoplanet Imager (HabEx) Science and Technology Definition Teams (STDT) on technical considerations regarding ultraviolet coatings, polarization, and coronagraphy. The presentations review the state-of-the-art in ultraviolet coatings, how those coatings generate polarization aberrations, and recent study results from both the LUVOIR and HabEx teams.

  19. Coatings for transport industry

    Directory of Open Access Journals (Sweden)

    Krzysztof LUKASZKOWICZ

    2014-09-01

    Full Text Available The investigations concerned structural analysis, as well as mechanical properties and wear resistant of MeN/DLC double-layer coating deposited by hybrid PVD/PACVD method. In sliding dry friction conditions, after the break-in time, the friction coefficient for the investigated elements is set in the range between 0.03-0.06.

  20. Ion Deposited Carbon Coatings.

    Science.gov (United States)

    1983-07-01

    PAGE ("’hen Dita t,,I,, efl TABLE OF CONTENTS Section No. Title Page No. 1.0 OBJECTIVE 1 2.0 SCOPE 2 3.0 BACKGROUND 3 4.0 COATINGS DEPOSITION 4 4.1...scientific, ards of measure. The Committee, and Confer- technical, practical, and teaching purposes.ence voting members, are leading professional On the

  1. Polydopamine-coated capsules

    Science.gov (United States)

    White, Scott R.; Sottos, Nancy R.; Kang, Sen; Baginska, Marta B.

    2018-04-17

    One aspect of the invention is a polymer material comprising a capsule coated with PDA. In certain embodiments, the capsule encapsulates a functional agent. The encapsulated functional agent may be an indicating agent, healing agent, protecting agent, pharmaceutical drug, food additive, or a combination thereof.

  2. Diamond-Like Carbon Coatings as Encapsulants for Photovoltaic Solar Cells

    International Nuclear Information System (INIS)

    Pern, F. J.; Panosyan, Zh.; Gippius, A. A.; Kontsevoy, J. A.; Touryan, K.; Voskanyan, S.; Yengibaryan, Y.

    2005-01-01

    High-quality single-layer and bilayer diamond-like carbon (DLC) thin films are fabricated by two technologies, namely, ion-assisted plasma-enhanced deposition (IAPED) and electron cyclotron resonance (ECR) deposition. Deposition on various substrates, such as sapphires and solar cells, has been performed at low substrate temperatures (50 ∼ 80 C). The two deposition technologies allow good control over the growth conditions to produce DLC films with desired optical properties, thickness, and energy bandgap. The bilayer-structured DLC can be fabricated by using IAPED for the bottom layer followed by ECR for the top layer, or just by IAPED for both layers with different compositions. The DLC films have shown good spatial uniformity, density, microhardness, and adhesion strength. They exhibit excellent stability against attack by strong acids, prolonged damp-heat exposure at 85 C and 85% relative humidity, mechanical scratch, ultrasonication, and irradiation by ultraviolet (UV), protons, and electrons. When deposited on crystalline Si and GaAs solar cells in single-layer and/or bilayer structure, the DLC films not only serve as antireflection coating and protective encapsulant, but also improve the cell efficiencies

  3. Active coatings technologies for tailorable military coating systems

    Science.gov (United States)

    Zunino, J. L., III

    2007-04-01

    The main objective of the U.S. Army's Active Coatings Technologies Program is to develop technologies that can be used in combination to tailor coatings for utilization on Army Materiel. The Active Coatings Technologies Program, ACT, is divided into several thrusts, including the Smart Coatings Materiel Program, Munitions Coatings Technologies, Active Sensor packages, Systems Health Monitoring, Novel Technology Development, as well as other advanced technologies. The goal of the ACT Program is to conduct research leading to the development of multiple coatings systems for use on various military platforms, incorporating unique properties such as self repair, selective removal, corrosion resistance, sensing, ability to modify coatings' physical properties, colorizing, and alerting logistics staff when tanks or weaponry require more extensive repair. A partnership between the U.S. Army Corrosion Office at Picatinny Arsenal, NJ along with researchers at the New Jersey Institute of Technology, NJ, Clemson University, SC, University of New Hampshire, NH, and University of Massachusetts (Lowell), MA, are developing the next generation of Smart Coatings Materiel via novel technologies such as nanotechnology, Micro-electromechanical Systems (MEMS), meta-materials, flexible electronics, electrochromics, electroluminescence, etc. This paper will provide the reader with an overview of the Active Coatings Technologies Program, including an update of the on-going Smart Coatings Materiel Program, its progress thus far, description of the prototype Smart Coatings Systems and research tasks as well as future nanotechnology concepts, and applications for the Department of Defense.

  4. Boosting Light Harvesting in Perovskite Solar Cells by Biomimetic Inverted Hemispherical Architectured Polymer Layer with High Haze Factor as an Antireflective Layer.

    Science.gov (United States)

    Kim, Dong Hyun; Dudem, Bhaskar; Jung, Jae Woong; Yu, Jae Su

    2018-04-18

    Biomimetic microarchitectured polymer layers, such as inverted hemispherical architectured (IHSA)-polydimethylsiloxane (PDMS) and hemispherical architectured (HSA)-PDMS layers, were prepared by a simple and cost-effective soft-imprinting lithography method via a hexagonal close-packed polystyrene microsphere array/silicon mold. The IHSA-PDMS/glass possessed superior antireflection (AR) characteristics with the highest/lowest average transmittance/reflectance ( T avg / R avg ) values of approximately 89.2%/6.4% compared to the HSA-PDMS/glass, flat-PDMS/glass, and bare glass ( T avg / R avg ∼88.8%/7.5%, 87.5%/7.9%, and 87.3%/8.8%, respectively). In addition, the IHSA-PDMS/glass also exhibited a relatively strong light-scattering property with the higher average haze ratio ( H avg ) of ∼38% than those of the bare glass, flat-PDMS/glass, and HSA-PDMS/glass (i.e., H avg ≈ 1.1, 1.7, and 34.2%, respectively). At last, to demonstrate the practical feasibility under light control of the solar cells, the IHSA-PDMS was laminated onto the glass substrates of perovskite solar cells (PSCs) as an AR layer, and their device performances were explored. Consequently, the short-circuit current density of the PSCs integrated with the IHSA-PDMS AR layer was improved by ∼17% when compared with the device without AR layer, resulting in the power conversion efficiency (PCE) up to 19%. Therefore, the IHSA-PDMS is expected to be applied as an AR layer for solar cells to enhance their light absorption as well as the PCE.

  5. Flow accelerated organic coating degradation

    Science.gov (United States)

    Zhou, Qixin

    Applying organic coatings is a common and the most cost effective way to protect metallic objects and structures from corrosion. Water entry into coating-metal interface is usually the main cause for the deterioration of organic coatings, which leads to coating delamination and underfilm corrosion. Recently, flowing fluids over sample surface have received attention due to their capability to accelerate material degradation. A plethora of works has focused on the flow induced metal corrosion, while few studies have investigated the flow accelerated organic coating degradation. Flowing fluids above coating surface affect corrosion by enhancing the water transport and abrading the surface due to fluid shear. Hence, it is of great importance to understand the influence of flowing fluids on the degradation of corrosion protective organic coatings. In this study, a pigmented marine coating and several clear coatings were exposed to the laminar flow and stationary immersion. The laminar flow was pressure driven and confined in a flow channel. A 3.5 wt% sodium chloride solution and pure water was employed as the working fluid with a variety of flow rates. The corrosion protective properties of organic coatings were monitored inline by Electrochemical Impedance Spectroscopy (EIS) measurement. Equivalent circuit models were employed to interpret the EIS spectra. The time evolution of coating resistance and capacitance obtained from the model was studied to demonstrate the coating degradation. Thickness, gloss, and other topography characterizations were conducted to facilitate the assessment of the corrosion. The working fluids were characterized by Fourier Transform Infrared Spectrometer (FTIR) and conductivity measurement. The influence of flow rate, fluid shear, fluid composition, and other effects in the coating degradation were investigated. We conclude that flowing fluid on the coating surface accelerates the transport of water, oxygen, and ions into the coating, as

  6. Evolution of micro-arc oxidation behaviors of the hot-dipping aluminum coatings on Q235 steel substrate

    International Nuclear Information System (INIS)

    Lu Lihong; Shen Dejiu; Zhang Jingwu; Song Jian; Li Liang

    2011-01-01

    Micro-arc oxidation (MAO) is not applicable to prepare ceramic coatings on the surface of steel directly. In this work, hybrid method of MAO and hot-dipping aluminum (HDA) were employed to fabricate composite ceramic coatings on the surface of Q235 steel. The evolution of MAO coatings, such as growth rate, thickness of the total coatings, ingrown and outgrown coatings, cross section and surface morphologies and phase composition of the ceramic coatings were studied. The results indicate that both the current density and the processing time can affect the total thickness, the growth rate and the ratio of ingrown and outgrown thickness of the ceramic coatings. The total thickness, outgrown thickness and growth rate have maximum values with the processing time prolonged. The time when the maximum value appears decreases and the ingrown dominant turns to outgrown dominant little by little with the current density increasing. The composite coatings obtained by this hybrid method consists of three layers from inside to outside, i.e. Fe-Al alloy layer next to the substrate, aluminum layer between the Fe-Al layer and the ceramic coatings which is as the top exterior layer. Metallurgical bonding was observed between every of the two layers. There are many micro-pores and micro-cracks, which act as discharge channels and result of quick and non-uniform cooling of melted sections in the MAO coatings. The phase composition of the ceramic coatings is mainly composed of amorphous phase and crystal Al 2 O 3 oxides. The crystal Al 2 O 3 phase includes κ-Al 2 O 3 , θ-Al 2 O 3 and β-Al 2 O 3 . Compared with the others, the β-Al 2 O 3 content is the least. The MAO process can be divided into three periods, namely the common anodic oxidation stage, the stable MAO stage and the ceramic coatings destroyed stage. The exterior loose part of the ceramic coatings was destroyed badly in the last period which should be avoided during the MAO process.

  7. Evolution of micro-arc oxidation behaviors of the hot-dipping aluminum coatings on Q235 steel substrate

    Energy Technology Data Exchange (ETDEWEB)

    Lu Lihong, E-mail: llh_qc@163.com [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China) and Research Department, The Chinese People' s Armed Police Academy, Langfang 065000 (China); Shen Dejiu; Zhang Jingwu [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Song Jian; Li Liang [Tsinghua University, State Key Laboratory of Automotive Safety and Energy, Beijing 100084 (China)

    2011-02-15

    Micro-arc oxidation (MAO) is not applicable to prepare ceramic coatings on the surface of steel directly. In this work, hybrid method of MAO and hot-dipping aluminum (HDA) were employed to fabricate composite ceramic coatings on the surface of Q235 steel. The evolution of MAO coatings, such as growth rate, thickness of the total coatings, ingrown and outgrown coatings, cross section and surface morphologies and phase composition of the ceramic coatings were studied. The results indicate that both the current density and the processing time can affect the total thickness, the growth rate and the ratio of ingrown and outgrown thickness of the ceramic coatings. The total thickness, outgrown thickness and growth rate have maximum values with the processing time prolonged. The time when the maximum value appears decreases and the ingrown dominant turns to outgrown dominant little by little with the current density increasing. The composite coatings obtained by this hybrid method consists of three layers from inside to outside, i.e. Fe-Al alloy layer next to the substrate, aluminum layer between the Fe-Al layer and the ceramic coatings which is as the top exterior layer. Metallurgical bonding was observed between every of the two layers. There are many micro-pores and micro-cracks, which act as discharge channels and result of quick and non-uniform cooling of melted sections in the MAO coatings. The phase composition of the ceramic coatings is mainly composed of amorphous phase and crystal Al{sub 2}O{sub 3} oxides. The crystal Al{sub 2}O{sub 3} phase includes {kappa}-Al{sub 2}O{sub 3}, {theta}-Al{sub 2}O{sub 3} and {beta}-Al{sub 2}O{sub 3}. Compared with the others, the {beta}-Al{sub 2}O{sub 3} content is the least. The MAO process can be divided into three periods, namely the common anodic oxidation stage, the stable MAO stage and the ceramic coatings destroyed stage. The exterior loose part of the ceramic coatings was destroyed badly in the last period which should be

  8. Coating of metals

    International Nuclear Information System (INIS)

    Smith, F.

    1978-01-01

    A method is described for coating the surface of an article of Ti, Zr or Ta, or an alloy thereof, with a tinning metal or alloy, the article having a shape other than that of a sheet. The method comprises contacting the surface of the article at an elevated temperature with the molten tinning metal and moving an ultrasonically excited probe over the surface to be coated, the probe being in contact with the surface of the article and with the tinning metal. The tinning metal may be Sn or Zn or a binary alloy of Sn with Zn, Cd or Bi at a temperature of 300 0 to 450 0 C. The head of the probe may be shaped to conform with the surface of the article. The method may be used to form composite articles, and may be applied to a pre-tinned steel article. (U.K.)

  9. Coat of Arms.

    Science.gov (United States)

    Smith, Bryan

    1998-01-01

    Describes an activity, the "coat of arms," that can serve as an ice-breaker or warm-up for the first day of an English-as-a-Second/Foreign-Language class, as a motivating start to the week, or act as an innovative segue between skill lessons. The technique can be adapted for students ranging from elementary school to adult language learners of all…

  10. Scientific coats of arms.

    Science.gov (United States)

    Fara, Patricia

    2005-09-01

    With their mythical creatures and arcane symbolism, coats of arms seem to have little connection with modern science. Yet despite its chivalric origins, the ancient language of heraldry has long fascinated famous scientists. Although this idiosyncratic tradition was parodied by Victorian geologists, who laughingly replaced unicorns and griffins with images of dinosaurs that they had recently discovered, it has been perpetuated since by Ernest Rutherford, who liked to present himself as a new alchemist.

  11. Anti-Corrosion Coating

    Science.gov (United States)

    1986-01-01

    SuperSpan RM 8000 is an anti-corrosion coating which effectively counteracts acid degradation, abrasive wear, and cracking in power industry facilities. It was developed by RM Industrial Products Company, Inc. with NERAC assistance. It had previously been necessary to shut down plants to repair or replace corroded duct-work in coal burning utilities. NASA-developed technology was especially useful in areas relating to thermoconductivity of carbon steel and the bonding characteristics of polymers. The product has sold well.

  12. for zeolite coating

    Directory of Open Access Journals (Sweden)

    Carlos Renato Rambo

    2006-01-01

    Full Text Available Biotemplating is the processing of microcellular ceramics by reproduction of natural morphologies, where the microstructural features of the biotemplate are maintained in the biomorphic ceramic. Different biotemplates with distinct pore anatomies were used to produce biomorphic supports for the zeolite coating: wood, cardboard, sea-sponge and sisal. The biomorphic ceramics were produced by distinguished processing routes: Al-gas infiltration-reaction, liquid-metal infiltration, dip-coating and sol-gel synthesis, in order to produce nitrides, carbides and oxides, depending on the processing conditions. The zeolite coating was performed by hydrothermal growth of MFI-type (Silicalite-1 and ZSM-5 zeolite crystals onto the internal pore walls of the biomorphic templates. The final biomorphic ceramic-zeolite composites were physically characterized, evaluated in terms of their gas adsorption capabilities and correlated to their microstructure and specific pore anatomy. The combination of the properties of the biomorphic ceramics with the adsorption properties of zeolites results in materials with distinct properties as potential candidates for adsorption and catalytic applications due to their characteristic porosity, molecular sieving capabilities and high thermo-mechanical strength.

  13. Coating and curing apparatus and methods

    Science.gov (United States)

    Brophy, Brenor L; Maghsoodi, Sina; Neyman, Patrick J; Gonsalves, Peter R; Hirsch, Jeffrey G; Yang, Yu S

    2015-02-24

    Disclosed are coating apparatus including flow coating and roll-coating that may be used for uniform sol-gel coating of substrates such as glass, solar panels, windows or part of an electronic display. Also disclosed are methods for substrate preparation, flow coating and roll coating. Lastly systems and methods for skin curing sol-gel coatings deposited onto the surface of glass substrates using a high temperature air-knife are disclosed.

  14. Lotus Dust Mitigation Coating and Molecular Adsorber Coating

    Science.gov (United States)

    O'Connor, Kenneth M.; Abraham, Nithin S.

    2015-01-01

    NASA Goddard Space Flight Center has developed two unique coating formulations that will keep surfaces clean and sanitary and contain contaminants.The Lotus Dust Mitigation Coating, modeled after the self-cleaning, water-repellant lotus leaf, disallows buildup of dust, dirt, water, and more on surfaces. This coating, has been successfully tested on painted, aluminum, glass, silica, and some composite surfaces, could aid in keeping medical assets clean.The Molecular Adsorber Coating is a zeolite-based, sprayable molecular adsorber coating, designed to prevent outgassing in materials in vacuums. The coating works well to adsorb volatiles and contaminates in manufacturing and processing, such as in pharmaceutical production. The addition of a biocide would also aid in controlling bacteria levels.

  15. Composition superconductive plumbous coatings

    International Nuclear Information System (INIS)

    Volodin, V.N.; Tuleushev, A.Zh.; Tuleushev, Yu.Zh.; Lisizin, V.N.

    2002-01-01

    Independent dispersion of two or more targets, precipitation of pulverized material on substrate and possibility of composition change in wide range of component concentrations made possible ion-plasma forming of film composition materials from materials with different chemical and physical qualities, particularly in lead-aluminum, lead-beryllium and lead-graphite systems. Named systems are characterized in wide sphere of immiscibility in solid and liquid state and absence of intermediate compounds. It is impossible to receive materials from them in traditional method in conditions of gravitational field. In lead-aluminum system there was received a number of film coatings with aluminum content up to 95 at. % at coating thickness up to 2 μm. Owing to X-ray investigations it is fixed that lead and aluminum have been performed by separate phases. Lead in sprayed layer represents well-crystallized phase with grain size more than 100 nm; texturing is not found. Study of physical qualities has shown that materials with lead base 21.6 at. % Al) have enough high crystalline current in comparison with compact lead, which reaches (2.5-3.0)·10 5 A)·cm 2 , while materials with aluminum base (21.6 at. % Al) loose this effect and critical temperature of transition is reduced from 7.1 to 5.8 K. It was impossible to carry out X-rayed analysis for lead-beryllium film because of weak intensity of beryllium lines against a background of lead owing to a quite large difference of atomic balance. Cryogen tests have shown the increase of critical current strength up to (3.1-3.6)·10 4 A)·cm 2 or composition coating of lead-beryllium (56.99 at. % or 5,45 mas. % Be), at that the critical temperature of transition does not differ from lead temperature. Samples of lead edge of state diagram have been received in the lead-graphite system. X-ray investigation subjected coating contained 6.81 at. % (55.82 mas. %) of lead. Choice of the composition is conditioned on possibilities of

  16. Nanoparticle/Polymer Nanocomposite Bond Coat or Coating

    Science.gov (United States)

    Miller, Sandi G.

    2011-01-01

    This innovation addresses the problem of coatings (meant to reduce gas permeation) applied to polymer matrix composites spalling off in service due to incompatibility with the polymer matrix. A bond coat/coating has been created that uses chemically functionalized nanoparticles (either clay or graphene) to create a barrier film that bonds well to the matrix resin, and provides an outstanding barrier to gas permeation. There is interest in applying clay nanoparticles as a coating/bond coat to a polymer matrix composite. Often, nanoclays are chemically functionalized with an organic compound intended to facilitate dispersion of the clay in a matrix. That organic modifier generally degrades at the processing temperature of many high-temperature polymers, rendering the clay useless as a nano-additive to high-temperature polymers. However, this innovation includes the use of organic compounds compatible with hightemperature polymer matrix, and is suitable for nanoclay functionalization, the preparation of that clay into a coating/bondcoat for high-temperature polymers, the use of the clay as a coating for composites that do not have a hightemperature requirement, and a comparable approach to the preparation of graphene coatings/bond coats for polymer matrix composites.

  17. Modeling of Thermal Barrier Coatings

    Science.gov (United States)

    Ferguson, B. L.; Petrus, G. J.; Krauss, T. M.

    1992-01-01

    The project examined the effectiveness of studying the creep behavior of thermal barrier coating system through the use of a general purpose, large strain finite element program, NIKE2D. Constitutive models implemented in this code were applied to simulate thermal-elastic and creep behavior. Four separate ceramic-bond coat interface geometries were examined in combination with a variety of constitutive models and material properties. The reason for focusing attention on the ceramic-bond coat interface is that prior studies have shown that cracking occurs in the ceramic near interface features which act as stress concentration points. The model conditions examined include: (1) two bond coat coefficient of thermal expansion curves; (2) the creep coefficient and creep exponent of the bond coat for steady state creep; (3) the interface geometry; and (4) the material model employed to represent the bond coat, ceramic, and superalloy base.

  18. Tablet coating by injection molding technology - Optimization of coating formulation attributes and coating process parameters.

    Science.gov (United States)

    Desai, Parind M; Puri, Vibha; Brancazio, David; Halkude, Bhakti S; Hartman, Jeremy E; Wahane, Aniket V; Martinez, Alexander R; Jensen, Keith D; Harinath, Eranda; Braatz, Richard D; Chun, Jung-Hoon; Trout, Bernhardt L

    2018-01-01

    We developed and evaluated a solvent-free injection molding (IM) coating technology that could be suitable for continuous manufacturing via incorporation with IM tableting. Coating formulations (coating polymers and plasticizers) were prepared using hot-melt extrusion and screened via stress-strain analysis employing a universal testing machine. Selected coating formulations were studied for their melt flow characteristics. Tablets were coated using a vertical injection molding unit. Process parameters like softening temperature, injection pressure, and cooling temperature played a very important role in IM coating processing. IM coating employing polyethylene oxide (PEO) based formulations required sufficient room humidity (>30% RH) to avoid immediate cracks, whereas other formulations were insensitive to the room humidity. Tested formulations based on Eudrajit E PO and Kollicoat IR had unsuitable mechanical properties. Three coating formulations based on hydroxypropyl pea starch, PEO 1,000,000 and Opadry had favorable mechanical (35% elongation, >95×10 4 J/m 3 toughness) and melt flow (>0.4g/min) characteristics, that rendered acceptable IM coats. These three formulations increased the dissolution time by 10, 15 and 35min, respectively (75% drug release), compared to the uncoated tablets (15min). Coated tablets stored in several environmental conditions remained stable to cracking for the evaluated 8-week time period. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Self-organized antireflection CuIn(S,Se)_2 nano-protrusions on flexible substrates by ion erosion based on CuInS_2 nanocrystal precursor inks

    International Nuclear Information System (INIS)

    Yen, Yu-Ting; Wang, Yi-Chung; Chen, Chia-Wei; Tsai, Hung-Wei; Chen, Yu-Ze; Hu, Fan; Chueh, Yu-Lun

    2015-01-01

    Highlights: • CuIn(S,Se)_2 nano-protrusions were demonstrated on 36-cm"2 flexible substrates. • Nano-protrusions were created by ion erosion on selenized CuInS_2 nanocrystal precursor inks. • Tilt orientations and remarkable anti-reflectance characteristics of nano-protrusions can be precisely controlled. - Abstract: In this work, an approach to achieve surface nano-protrusions on a chalcopyrite CuIn(S,Se)_2 thin film was demonstrated. Home-made CuInS_2 nanocrystals with average diameter of 20 nm were prepared and characterized. By applying ion erosion process on the CuIn(S,Se)_2 film, large-area self-aligned nano-protrusions can be formed. Interestingly, the process can be applied on flexible substrate where the CuIn(S,Se)_2 film remains intact with no visible cracking after several bending tests. In addition, reflectance spectra reveal the extraordinary anti-reflectance characteristics of nano-protrusions on the CuIn(S,Se)_2 film with the incident light from 350 to 2000 nm. A 36-cm"2 CuIn(S,Se)_2 film with nano-protrusions on flexible molybdenum foil substrate has been demonstrated, which demonstrated the feasibility of developing low cost with a high optical absorption CuIn(S,Se)_2 flexible thin film.

  20. Epoxy coatings for anticorrosion challenges: a link between chemistry and performance?

    Energy Technology Data Exchange (ETDEWEB)

    Sauvant-Moynot, Valerie; Schweitzer, Sylvie; Grenier, Jacky; Duval, Sebastien [Institut Francais du Petrole, 1 et 4 avenue Bois Preau, 92450 Rueil-Malmaison (France)

    2004-07-01

    Epoxy coatings have been used extensively for pipeline protection in the oil and gas industries over the past decades. Thank to their outstanding adhesive properties, epoxy resins are classically used for external coating of offshore pipelines although cathodic protection is applied. They provide corrosion protection while being used as neat coating or as primer layer in a three-layer coating. Protection of internal pipelines devoted to gas transport is another application of epoxy coatings. Whatever the case, the choice of the right epoxy formulation should be adapted to the service conditions, namely exposition medium and temperature, in order to provide efficient and sustainable corrosion protection. Epoxy resins constitute a wide family and classical formulations may not fulfill the requirements of today's challenges: as pipelines are require d to operate in more and more difficult conditions, coatings are expected to function in higher temperature conditions; additionally, practical conditions such as temporary injection of methanol make the environmental exposure of the epoxy coating harsher. Therefore, there is a need of a better knowledge of technical performance and limitations of high temperature epoxy resins. This paper examined the influence of the epoxy network architecture on their protection properties and durability while exposed to distilled / sea water at 110 deg. C and to methanol at room temperature. The objective was to investigate the link between resin chemistry and final performance with respect to anticorrosion applications. Five epoxy resin formulations mixed in stoichiometric proportions were cured and post-cured to infinite extent in order to achieve densely cross-linked networks exhibiting controlled and reproducible architectures. Gravimetric and pressurised differential scanning calorimetry (DSC) measurements were performed to evaluate the plasticization effect of both water and methanol on formulations under study. The related

  1. Article Including Environmental Barrier Coating System

    Science.gov (United States)

    Lee, Kang N. (Inventor)

    2015-01-01

    An enhanced environmental barrier coating for a silicon containing substrate. The enhanced barrier coating may include a bond coat doped with at least one of an alkali metal oxide and an alkali earth metal oxide. The enhanced barrier coating may include a composite mullite bond coat including BSAS and another distinct second phase oxide applied over said surface.

  2. Coatings for fusion reactor environments

    International Nuclear Information System (INIS)

    Mattox, D.M.

    1979-01-01

    The internal surfaces of a tokamak fusion reactor control the impurity injection and gas recycling into the fusion plasma. Coating of internal surfaces may provide a desirable and possibly necessary design flexibility for achieving the temperatures, ion densities and containment times necessary for net energy production from fusion reactions to take place. In this paper the reactor environments seen by various componentare reviewed along with possible materials responses. Characteristics of coating-substrate systems, important to fusion applications, are delineated and the present status of coating development for fusion applications is reviewed. Coating development for fusion applications is just beginning and poses a unique and important challenge for materials development

  3. Properties of radiation cured coatings

    International Nuclear Information System (INIS)

    Larson, E.G.; Spencer, D.S.; Boettcher, T.E.; Melbauer, M.A.; Skarjune, R.P.

    1987-01-01

    Coatings were prepared from acrylate or methacrylate functionalized resins to study the effect of end group functionality on the physical properties of u.v. and electron beam cured coatings. Cure response was measured by solid state NMR and gel extraction, as expected, methacrylate resins cured much slower. Thermal Gravimetric Analysis (TGA) revealed acrylate coatings have greater thermal stability. Properties such as tensile strength and hardness showed little effect of end group functionality or curing method. The O 2 and H 2 O permeabilities of the coating were correlated with the processing conditions. (author)

  4. Decontamination and coating of lead

    International Nuclear Information System (INIS)

    Rankin, W.N.; Bush, S.P.; Lyon, C.E.; Walker, V.

    1988-01-01

    Technology is being developed to decontaminate lead used in shielding applications in contaminated environments for recycle as shieldings. Technology is also being developed to coat either decontaminated lead or new lead before it is used in contaminated environments. The surface of the coating is expected to be much easier to decontaminate than the original lead surface. If contamination becomes severely embedded in the coating and cannot be removed, it can be easily cut with a knife and removed from the lead. The used coating can be disposed of as radioactive (hot hazardous) waste. The lead can then be recoated for further use as a shielding material

  5. Coatings Technology Integration Office (CTIO)

    Data.gov (United States)

    Federal Laboratory Consortium — CTIO serves as the Air Force's central resource for aircraft coating systems and their applications. CTIO's primary objectives are pollution prevention and improved...

  6. Coating material composition

    International Nuclear Information System (INIS)

    Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Maeda, Yutaka.

    1969-01-01

    A coating material composition is provided which can easily be cross-linked by irradiation with active energy, particularly electron beams and ultraviolet light, using a mixture of a prepolymer (a) with an addition reaction product (b). Such compositions have coating properties as good as thermosetting acrylic or amino alkyd resins. The prepolymer (a) is produced by primarily reacting at least 0.1 mol of saturated cyclocarboxylic acid anhydrides and/or alpha-, beta-ethylene unsaturated carboxylic acid anhydrides by addition reaction with one mol of hydroxyl radicals of a basic polymer having a molecular weight of 1,000 to 100,000, the basic polymer being obtained from 1%-40% of a hydroxyl radical containing vinyl monomer and at least 30% of (meth)acrylate monomer. One mol of the sum of hydroxyl radicals and carboxyl radicals of the primary reaction product undergoes a secondary addition reaction with at least 0.1 mol of an epoxy radical-containing vinyl monomer to form the prepolymer(a). The addition reaction product(b) is produced by reacting an epoxy radical-containing vinyl monomer with alpha-, beta-ethylene unsaturated carboxylic acids or their anhydrides. The coating material composition contains a majority of a mixture consisting of 10%-90% of (a) and 90%-10% of (b) above by weight. Four examples of the production of basic polymers, seven examples of the production of prepolymers, seven examples of the production of oligomers, and five examples of applications are given. (Iwakiri, K.)

  7. Microplasma sprayed hydroxyapatite coatings

    CERN Document Server

    Dey, Arjun

    2015-01-01

    ""This unique book on development of microplasma sprayed HAp coating has been organized in a very compact yet comprehensive manner. This book also highlights the horizons of future research that invites the attention of global community, particularly those in bio-medical materials and bio-medical engineering field. This book will surely act as a very useful reference material for both graduate/post-graduate students and researchers in the field of biomedical, orthopedic and manufacturing engineering and research. I truly believ that this is the first ever effort which covers almost all the

  8. SPS: scrubbing or coating ?

    CERN Document Server

    Jimenez, J M

    2012-01-01

    The operation of the SPS with high intensity bunched beams is limited by the electron cloud building-up in both the arcs and long straight sections. Two consolidation options have been considered: mitigation of the electron cloud using coatings or relying, as before, on the scrubbing runs. A status report on both options will be given with a particular emphasis on measurements plans for 2012 and pending issues. The testing needs, corresponding beam parameters and MD time in 2012 will be addressed. The criteria for the decision making and the corresponding schedule will be discussed.

  9. SPS: scrubbing or coating?

    International Nuclear Information System (INIS)

    Jimenez, J.M.

    2012-01-01

    The operation of the SPS with high intensity bunched beams is limited by the electron cloud building-up in both the arcs and long straight sections. Two consolidation options have been considered: suppression of the electron cloud build-up using coatings or relying, as before, on the scrubbing mitigation. A status report on both options will be given with a particular emphasis on measurements plans for 2012 and pending issues. The testing needs, corresponding beam parameters and MD time in 2012 will be addressed. The criteria for the decision making and the corresponding schedule will be discussed. (author)

  10. Radiation hardenable coating mixture

    International Nuclear Information System (INIS)

    Howard, D.D.

    1977-01-01

    This invention relates to coatings that harden under radiation and to their compositions. Specifically, this invention concerns unsaturated urethane resins polymerisable by addition and to compositions, hardening under the effect of radiation, containing these resins. These resins feature the presence of at least one unsaturated ethylenic terminal group of structure CH 2 =C and containing the product of the reaction of an organic isocyanate compound with at least two isocyanate groups and one polyester polyol with at least two hydroxyl groups, and one unsaturated monomer compound polymerisable by addition having a single active hydrogen group reacting with the isocyanate [fr

  11. Federal Highway Administration 100-year coating study.

    Science.gov (United States)

    2012-11-01

    The Federal Highway Administration 100-Year Coating Study was initiated in August 2009 to search for durable : coating systems at a reasonable cost. The objective of the study was to identify and evaluate coating materials that can : provide 100 year...

  12. Decoding white coat hypertension

    Science.gov (United States)

    Bloomfield, Dennis A; Park, Alex

    2017-01-01

    There is arguably no less understood or more intriguing problem in hypertension that the “white coat” condition, the standard concept of which is significantly blood pressure reading obtained by medical personnel of authoritative standing than that obtained by more junior and less authoritative personnel and by the patients themselves. Using hospital-initiated ambulatory blood pressure monitoring, the while effect manifests as initial and ending pressure elevations, and, in treated patients, a low daytime profile. The effect is essentially systolic. Pure diastolic white coat hypertension appears to be exceedingly rare. On the basis of the studies, we believe that the white coat phenomenon is a common, periodic, neuro-endocrine reflex conditioned by anticipation of having the blood pressure taken and the fear of what this measurement may indicate concerning future illness. It does not change with time, or with prolonged association with the physician, particularly with advancing years, it may be superimposed upon essential hypertension, and in patients receiving hypertensive medication, blunting of the nighttime dip, which occurs in about half the patients, may be a compensatory mechanisms, rather than an indication of cardiovascular risk. Rather than the blunted dip, the morning surge or the widened pulse pressure, cardiovascular risk appears to be related to elevation of the average night time pressure. PMID:28352632

  13. Ceramic protective coating

    International Nuclear Information System (INIS)

    Harbach, F.; Nicoll, A.

    1987-01-01

    The basic material of the above-mentioned layer consists of pure aluminium oxide or essentially aluminium oxide. To improve this protective layer metal oxides from the groups IIA, IIIA, IIIB, VB, VIB, VIIB or VIII of the periodic system are added to its basic material before the said protective coating is applied. In this way a corundum structure is formed in the case of aluminium oxide. Gallium oxide, vanadium oxide, chromium oxide or iron oxide are particularly suited for the correlation of such a corundum structure. The formation of the corundum structure increases the resistance of the protective coating to the corrosive effects of vanadium pentoxide and sodium sulfate. By the addition of a specific quantity of magnesium oxide it is possible not only to stimulate the formation of corundum but also to reduce the increase in grain size in the case of the aluminium oxide. The other metallic oxides are especially favorable to the formation of the corundum structure, so that preferably magnesium oxide is to be added to these metallic oxides in order to reduce the increase in grain size. (author)

  14. Rapidly curable electrically conductive clear coatings

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, Mark P.; Anderson, Lawrence G.; Post, Gordon L.

    2018-01-16

    Rapidly curable electrically conductive clear coatings are applied to substrates. The electrically conductive clear coating includes to clear layer having a resinous binder with ultrafine non-stoichiometric tungsten oxide particles dispersed therein. The clear coating may be rapidly cured by subjecting the coating to infrared radiation that heats the tungsten oxide particles and surrounding resinous binder. Localized heating increases the temperature of the coating to thereby thermally cure the coating, while avoiding unwanted heating of the underlying substrate.

  15. White coat hypertension in pediatrics.

    Science.gov (United States)

    Jurko, Alexander; Minarik, Milan; Jurko, Tomas; Tonhajzerova, Ingrid

    2016-01-15

    The article summarizes current information on blood pressure changes in children during clinic visit. White coat as a general dressing of physicians and health care personnel has been widely accepted at the end of the 19th century. Two problems can be associated with the use of white coat: white coat phenomenon and white coat hypertension. Children often attribute pain and other unpleasant experience to the white coat and refuse afterwards cooperation with examinations. Definition of white coat hypertension in the literature is not uniform. It has been defined as elevated blood pressure in the hospital or clinic with normal blood pressure at home measured during the day by ambulatory blood pressure monitoring system. White coat effect is defined as temporary increase in blood pressure before and during visit in the clinic, regardless what the average daily ambulatory blood pressure values are. Clinical importance of white coat hypertension is mainly because of higher risk for cardiovascular accidents that are dependent on end organ damage (heart, vessels, kidney). Current data do not allow any clear recommendations for the treatment. Pharmacological therapy is usually started in the presence of hypertrophic left ventricle, changes in intimal/medial wall thickness of carotic arteries, microalbuminuria and other cardiovascular risk factors. Nonpharmacological therapy is less controversial and certainly more appropriate. Patients have to change their life style, need to eliminate as much cardiovascular risk factors as possible and sustain a regular blood pressure monitoring.

  16. External coating of colonic anastomoses

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Rosenberg, Jacob

    2012-01-01

    Colon anastomotic leakage remains both a frequent and serious complication in gastrointestinal surgery. External coating of colonic anastomoses has been proposed as a means to lower the rate of this complication. The aim of this review was to evaluate existing studies on external coating of colonic...

  17. Moisture transport in coated wood

    NARCIS (Netherlands)

    Meel, P.A. van; Erich, S.J.F.; Huinink, H.P.; Kopinga, K.; Jong, J. DE; Adan, O.C.G.

    2011-01-01

    Moisture accumulation inside wood causes favorable conditions for decay. Application of a coating alters the moisture sorption of wood and prevents accumulation of moisture. This paper presents the results of a nuclear magnetic resonance (NMR) study on the influence of a coating on the moisture

  18. Electroless alloy/composite coatings

    Indian Academy of Sciences (India)

    The market for these coatings is expanding fast as the potential applications are on the rise. In the present article, an attempt has been made to review different electroless alloy/composite coatings with respect to bath types and their composition, properties and applications. Different characterisation studies have been ...

  19. Lignin based controlled release coatings

    NARCIS (Netherlands)

    Mulder, W.J.; Gosselink, R.J.A.; Vingerhoeds, M.H.; Harmsen, P.F.H.; Eastham, D.

    2011-01-01

    Urea is a commonly used fertilizer. Due to its high water-solubility, misuse easily leads to excess nitrogen levels in the soil. The aim of this research was to develop an economically feasible and biodegradable slow-release coating for urea. For this purpose, lignin was selected as coating

  20. Foundry Coating Technology: A Review

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat

    2011-01-01

    is important. In this review, a detailed description of these topics and examples are provided where necessary. A potential area of research in foundry coating development, using sol-gel process is suggested. The application of sol-gel technology in the development of foundry coatings is a novel approach....

  1. Intumescent coatings under fast heating

    DEFF Research Database (Denmark)

    Nørgaard, Kristian Petersen; Dam-Johansen, Kim; Català, Pere

    2012-01-01

    Intumescent coatings are widely used to delay or minimise the destructive effects of fire. They are usually tested under conditions that simulate the relatively slow build-up of heat in a normal fire. Here, the effects of damage during a fire causing sudden heating of the coating were studied....

  2. Steam initiated hydrotalcite conversion coatings

    DEFF Research Database (Denmark)

    Zhou, Lingli; Friis, Henrik; Roefzaad, Melanie

    2018-01-01

    A facile process of exploiting high-temperature steam to deposit nvironmentally friendly hydrotalcite (HT) coatings on Al alloy 6060 was developed in a spray system. Scanning electron microscopy showed the formationf a continuous and conformal coating comprised of a compact mass of crystallites. ...

  3. Evanescent wave assisted nanomaterial coating.

    Science.gov (United States)

    Mondal, Samir K; Pal, Sudipta Sarkar; Kumbhakar, Dharmadas; Tiwari, Umesh; Bhatnagar, Randhir

    2013-08-01

    In this work we present a novel nanomaterial coating technique using evanescent wave (EW). The gradient force in the EW is used as an optical tweezer for tweezing and self-assembling nanoparticles on the source of EW. As a proof of the concept, we have used a laser coupled etched multimode optical fiber, which generates EW for the EW assisted coating. The section-wise etched multimode optical fiber is horizontally and superficially dipped into a silver/gold nanoparticles solution while the laser is switched on. The fiber is left until the solution recedes due to evaporation leaving the fiber in air. The coating time usually takes 40-50 min at room temperature. The scanning electron microscope image shows uniform and thin coating of self-assembled nanoparticles due to EW around the etched section. A coating thickness optical fiber probes and other plasmonic circuits.

  4. Functional Plasma-Deposited Coatings

    Directory of Open Access Journals (Sweden)

    Mykhaylo Pashechko

    2017-12-01

    Full Text Available The paper focuses on the problem of low adhesion of plasma sprayed coatings to the substrate. The subsequent laser treatment modes and their influence on the coating-substrate interface were studied. This allows to decrease the level of metstability of the coating, thus decreasing its hardness down to 11-12 GPa on the surface and to about 9 GPa on depth of 400 µm. The redistribution of alloying elements through solid and liquid diffusion improves mechanical properties and rises the adhesion up to 450 MPa after remelting and up to 90-110 MPa after laser-aided thermal cycling. At he same time, remelting of coating helps to decrease its porosity down to 1%. Obtained complex of properties also allows to improve wear resistance of coatings and to decrease friction factor.

  5. Self-Healing anticorrosive coatings

    DEFF Research Database (Denmark)

    Nesterova, Tatyana

    %. The number is lower than anticipated and needs to be confirmed. Finally, a 3-D model, based on Monte-Carlo simulations, has been developed for prediction of healing efficiency of a microcapsule-based anticorrosive coating. Two kinds of cracks were considered: cracks accommodated within the bulk coating...... associated with development and testing of this type of coating. A laboratory investigation, to identify the most suitable method for production of mechanically stable (filled with industrially relevant core materials) and forming a free-flowing powder upon drying microcapsules, has been performed. Four...... reduces the intensity of crack formation (both in number and length) compared to filler-containing coatings and prevents the coating from flaking upon damage. Based on specular gloss measurements, a preliminary critical pigment (microcapsule) concentration (CPVC) value was estimated to about 30 vol...

  6. Understanding particulate coating microstructure development

    Science.gov (United States)

    Roberts, Christine Cardinal

    How a dispersion of particulates suspended in a solvent dries into a solid coating often is more important to the final coating quality than even its composition. Essential properties like porosity, strength, gloss, particulate order, and concentration gradients are all determined by the way the particles come together as the coating dries. Cryogenic scanning electron microscopy (cryoSEM) is one of the most effective methods to directly visualize a drying coating during film formation. Using this method, the coating is frozen, arresting particulate motion and solidifying the sample so that it be imaged in an SEM. In this thesis, the microstructure development of particulate coatings was explored with several case studies. First, the effect of drying conditions was determined on the collapse of hollow latex particles, which are inexpensive whiteners for paint. Using cryoSEM, it was found that collapse occurs during the last stages of drying and is most likely to occur at high drying temperatures, humidity, and with low binder concentration. From these results, a theoretical model was proposed for the collapse of a hollow latex particle. CryoSEM was also used to verify a theoretical model for the particulate concentration gradients that may develop in a coating during drying for various evaporation, sedimentation and particulate diffusion rates. This work created a simple drying map that will allow others to predict the character of a drying coating based on easily calculable parameters. Finally, the effect of temperature on the coalescence and cracking of latex coatings was explored. A new drying regime for latex coatings was identified, where partial coalescence of particles does not prevent cracking. Silica was shown to be an environmentally friendly additive for preventing crack formation in this regime.

  7. Facile and Low-Temperature Fabrication of Thermochromic Cr2O3/VO2 Smart Coatings: Enhanced Solar Modulation Ability, High Luminous Transmittance and UV-Shielding Function.

    Science.gov (United States)

    Chang, Tianci; Cao, Xun; Li, Ning; Long, Shiwei; Gao, Xiang; Dedon, Liv R; Sun, Guangyao; Luo, Hongjie; Jin, Ping

    2017-08-09

    In the pursuit of energy efficient materials, vanadium dioxide (VO 2 ) based smart coatings have gained much attention in recent years. For smart window applications, VO 2 thin films should be fabricated at low temperature to reduce the cost in commercial fabrication and solve compatibility problems. Meanwhile, thermochromic performance with high luminous transmittance and solar modulation ability, as well as effective UV shielding function has become the most important developing strategy for ideal smart windows. In this work, facile Cr 2 O 3 /VO 2 bilayer coatings on quartz glasses were designed and fabricated by magnetron sputtering at low temperatures ranging from 250 to 350 °C as compared with typical high growth temperatures (>450 °C). The bottom Cr 2 O 3 layer not only provides a structural template for the growth of VO 2 (R), but also serves as an antireflection layer for improving the luminous transmittance. It was found that the deposition of Cr 2 O 3 layer resulted in a dramatic enhancement of the solar modulation ability (56.4%) and improvement of luminous transmittance (26.4%) when compared to single-layer VO 2 coating. According to optical measurements, the Cr 2 O 3 /VO 2 bilayer structure exhibits excellent optical performances with an enhanced solar modulation ability (ΔT sol = 12.2%) and a high luminous transmittance (T lum,lt = 46.0%), which makes a good balance between ΔT sol and T lum for smart windows applications. As for UV-shielding properties, more than 95.8% UV radiation (250-400 nm) can be blocked out by the Cr 2 O 3 /VO 2 structure. In addition, the visualized energy-efficient effect was modeled by heating a beaker of water using infrared imaging method with/without a Cr 2 O 3 /VO 2 coating glass.

  8. Optical coating preparation

    International Nuclear Information System (INIS)

    Belleville, P.; Sabary, F.; Marcel, C.

    2003-01-01

    In order to optimize the properties of optical components, thin film deposition with controlled thickness and refractive index is often needed. Two different deposition techniques are proposed in this article and illustrated with examples: physical vapor deposition (PVD) and liquid sol-gel process (LSG). PVD and LSG techniques are equivalent as far as the following topics are concerned: elaboration of oxide or composite coated material, optical performance, mechanical performance, and laser performance. PVD is better for the elaboration of metallic films, the design of multi-layers or complex pile-up of layers. LSG is better for the treatment of large surfaces, for substrates with complicated shapes and for its low cost. PVD technique has been widely used so it benefited from an industrial maturity and a clean technology concerning wastes and effluents. On the contrary LSG is a new technique not yet widely used in industrial processes but that looks promising. (A.C.)

  9. Novel coating compositions

    International Nuclear Information System (INIS)

    Kimura, Tadashi; Kobayashi, Juichi; Nakamoto, Hideo.

    1969-01-01

    An acrylic coating composition rapidly hardenable by irradiating with ionizing radiations or light beams is given using hydroxyl group-containing vinyl monomers, polycarboxylic acid anhydrides, epoxy group-containing vinyl monomers and an organic solvent having a boiling point of at least 120 0 C. The process comprises the steps of first and second reactions. The first reaction takes place between one mol of a hydroxyl group of a basic polymer and at least 0.1 mol of polycarboxylic acid anhydride, wherein the basic polymer has a molecular weight ranging from 5,000 to 100,000 and consists of 1-40% by weight of vinyl monomer containing hydroxyl group, at least 30% of (meth)acrylic monomer and other vinyl monomers if required. The second reaction takes place between one mol of hydroxyl plus a carboxyl group of the thus obtained basic polymer and at least 0.1 mol of an epoxy group-containing vinyl monomer to produce a prepolymer. The prepolymer is mixed with a solvent such as ethyl benzene to produce the coating material. The electron beam accelerator energy level may be 0.1-2.0 MeV. In light beam polymerization, benzoin is particularly utilized as an intensifying substance. In one example, a basic polymer is produced by reacting 39 parts of styrene, 37 parts of ethyl acrylate, 24 parts of 2-hydroxyl ethyl acrylate, 4 parts of dimethyl amino ethyl methacrylate and others. A prepolymer is produced by reacting this basic polymer with 30 parts of glycidyl acrylate and others. (Iwakiri, K.)

  10. How PE tape performs under concrete coating

    International Nuclear Information System (INIS)

    Dritt, H.J.

    1984-01-01

    The program objectives were to evaluate the performance of polyethylene tape plant coating and fusion bonded epoxy powder systems with particular respect to the following: 1. Concrete coating application procedures; 2. The shear resistance during laying and retrieving operations of the coating at the various interfaces (a) Pipe and anti-corrosion coating; (b) Anti-corrosion coating and outerwrap; (c) Overlap areas of the anti-corrosion and outerwrap layers; (d) Between concrete and the various corrosion coatings during laying and retrieving operations. 3. Resistance to damage of the coating as a consequence of cracking or slippage of the concrete weight coating. 4. Ability of various coatings to withstand the damage during concrete application by both impact and compression methods; 5. Evaluation of tape and shrink sleeve joint coatings at the cut-back area as well as performance of tape under hot asphalt coating

  11. Avian Egg and Egg Coat.

    Science.gov (United States)

    Okumura, Hiroki

    2017-01-01

    An ovulated egg of vertebrates is surrounded by unique extracellular matrix, the egg coat or zona pellucida, playing important roles in fertilization and early development. The vertebrate egg coat is composed of two to six zona pellucida (ZP) glycoproteins that are characterized by the evolutionarily conserved ZP-domain module and classified into six subfamilies based on phylogenetic analyses. Interestingly, investigations of biochemical and functional features of the ZP glycoproteins show that the roles of each ZP-glycoprotein family member in the egg-coat formation and the egg-sperm interactions seemingly vary across vertebrates. This might be one reason why comprehensive understandings of the molecular basis of either architecture or physiological functions of egg coat still remain elusive despite more than 3 decades of intensive investigations. In this chapter, an overview of avian egg focusing on the oogenesis are provided in the first section, and unique features of avian egg coat, i.e., perivitelline layer, including the morphology, biogenesis pathway, and physiological functions are discussed mainly on chicken and quail in terms of the characteristics of ZP glycoproteins in the following sections. In addition, these features of avian egg coat are compared to mammalian zona pellucida, from the viewpoint that the structural and functional varieties of ZP glycoproteins might be associated with the evolutionary adaptation to their reproductive strategies. By comparing the egg coat of birds and mammals whose reproductive strategies are largely different, new insights into the molecular mechanisms of vertebrate egg-sperm interactions might be provided.

  12. Hot corrosion of the ceramic composite coating Ni{sub 3}Al-Al{sub 2}O{sub 3}-Al{sub 2}O{sub 3}/MgO plasma sprayed on 316L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Shirazi, Amir Khodaparast; Kiahosseini, Seyed Rahim [Islamic Azad Univ., Damghan (Iran, Islamic Republic of). Dept. of Engineering

    2017-08-15

    Ni{sub 3}Al-Al{sub 2}O{sub 3}-Al{sub 2}O{sub 3}/MgO three-layered coatings with thicknesses of 50, 100, and 150 μm for Al{sub 2}O{sub 3}/MgO and 100 μm for the other layers were deposited on 316L stainless steel using plasma spraying. X-ray diffraction, atomic force microscopy, furnace hot corrosion testing in the presence of a mixture of Na{sub 2}SO{sub 4} and V{sub 2}O{sub 5} corrosive salts and scanning electron microscopy were used to determine the structural, morphological and hot corrosion resistance of samples. Results revealed that the crystalline grains of MgO and Al{sub 2}O{sub 3} coating were very small. Weight loss due to hot corrosion decreased from approximately 4.267 g for 316L stainless steel without coating to 2.058 g. The samples with 150 μm outer coating showed improved resistance with the increase in outer layer thickness. Scanning electron microscopy of the coated surface revealed that the coating's resistance to hot corrosion is related to the thickness and the grain size of Al{sub 2}O{sub 3}/MgO coatings.

  13. Perfect antireflection via negative refraction

    International Nuclear Information System (INIS)

    Monzon, Juan J.; Barriuso, Alberto G.; Sanchez-Soto, Luis L.

    2006-01-01

    We suggest a geometrical framework to discuss the action of slabs of negatively refracting materials. We show that these slabs generate the same orbits as normal materials, but traced out in opposite directions. This property allows us to confirm that the action of any lossless multilayer can be optically canceled by putting it together with the multilayer constructed as the inverted mirror image, with ε and μ reversed in sign

  14. Intumescent Coatings as Fire Retardants

    Science.gov (United States)

    Parker, J. A.; Fohlen, G. M.; Sawko, P. M.; Fish, R. H.

    1970-01-01

    The development of fire-retardant coatings to protect surfaces which may be exposed to fire or extreme heat is a subject of intense interest to many industries. A fire-retardant paint has been developed which represents a new chemical approach for preparing intumescent coatings, and potentially, is very important to fire-prevention authorities. The requirements for a superior coating include ease of application, suitability to a wide variety of surfaces and finishes, and stability over an extended period of time within a broad range of ambient temperature and humidity conditions. These innovative coatings, when activated by the heat of a fire, react to form a thick, low-density, polymeric coating or char layer. Water vapor and sulphur dioxide are released during the intumescent reaction. Two fire-protection mechanisms thus become available: (1) the char layer retards the flow of heat, due to the extremely low thermal conductivity; and (2) water vapor and sulfur dioxide are released, providing fire quenching properties. Still another mechanism functions in cases where the char, by virtue of its high oxidation resistance and low thermal conductivity, reaches a sufficiently high temperature to re-radiate much of the incident heat load. The coatings consist of dispersions of selective salts of a nitro-amino-arornatic compound. Specifically, para-nitroaniline bisulfate and the ammonium salt of para-nitroaniline-ortho sulphuric acid (2-amino-5-nitrobenzenesulphuric acid) are used. Suitable vehicles are cellulose nitrate of lacquer grade, a nitrite-phenolic modified rubber, or epoxy-polysulfide copolymer. Three separate formulations have been developed. A solvent is usually employed, such as methylethyl ketone, butyl acetate, or toluene, which renders the coatings suitably thin and which evaporates after the coatings are applied. Generally, the intumescent material is treated as insoluble in the vehicle, and is ground and dispersed in the vehicle and solvent like an

  15. Integrated Glass Coating Manufacturing Line

    Energy Technology Data Exchange (ETDEWEB)

    Brophy, Brenor [Enki Technology Inc., San Jose, CA (United States)

    2015-09-30

    This project aims to enable US module manufacturers to coat glass with Enki’s state of the art tunable functionalized AR coatings at the lowest possible cost and highest possible performance by encapsulating Enki’s coating process in an integrated tool that facilitates effective process improvement through metrology and data analysis for greater quality and performance while reducing footprint, operating and capital costs. The Phase 1 objective was a fully designed manufacturing line, including fully specified equipment ready for issue of purchase requisitions; a detailed economic justification based on market prices at the end of Phase 1 and projected manufacturing costs and a detailed deployment plan for the equipment.

  16. Laser-based coatings removal

    International Nuclear Information System (INIS)

    Freiwald, J.G.; Freiwald, D.A.

    1995-01-01

    Over the years as building and equipment surfaces became contaminated with low levels of uranium or plutonium dust, coats of paint were applied to stabilize the contaminants in place. Most of the earlier paint used was lead-based paint. More recently, various non-lead-based paints, such as two-part epoxy, are used. For D ampersand D (decontamination and decommissioning), it is desirable to remove the paints or other coatings rather than having to tear down and dispose of the entire building. This report describes the use of pulse-repetetion laser systems for the removal of paints and coatings

  17. Hydrogen permeation resistant phosphate coatings

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1979-01-01

    A method for reducing hydrogen diffusion through metal wherein the metal is coated with a phosphate-radical-containing, phosphate-glass-forming material on at least one surface thereof. The coating is then heated to at least 350 0 C to form a phosphate glass. This method is especially applicable to nuclear reactors to minimize tritium diffusion. The coating is preferably formed with a solution of phosphoric acid which may also contain compounds such as MnSO 4 , SiO 2 and Na 2 Cr 2 0 7 . (author)

  18. Hydrogen permeation resistant phosphate coatings

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1979-01-01

    A method for reducing hydrogen diffusion through metal is described. The metal is coated with a phosphate-radical-containing, phosphate-glass-forming material on at least one surface. The coating is then heated to at least 350 0 C to form a phosphate glass. This method is especially applicable to nuclear reactors to minimize tritium diffusion. The coating is preferably formed with a solution of phosphoric acid which may also contain compounds such as MnSO 4 , SiO 2 and Na 2 Cr 2 O 7 . (author)

  19. Laser-based coatings removal

    Energy Technology Data Exchange (ETDEWEB)

    Freiwald, J.G.; Freiwald, D.A. [F2 Associates, Inc., Albuquerque, NM (United States)

    1995-10-01

    Over the years as building and equipment surfaces became contaminated with low levels of uranium or plutonium dust, coats of paint were applied to stabilize the contaminants in place. Most of the earlier paint used was lead-based paint. More recently, various non-lead-based paints, such as two-part epoxy, are used. For D&D (decontamination and decommissioning), it is desirable to remove the paints or other coatings rather than having to tear down and dispose of the entire building. This report describes the use of pulse-repetetion laser systems for the removal of paints and coatings.

  20. Solution-deposited F:SnO₂/TiO₂ as a base-stable protective layer and antireflective coating for microtextured buried-junction H₂-evolving Si photocathodes.

    Science.gov (United States)

    Kast, Matthew G; Enman, Lisa J; Gurnon, Nicholas J; Nadarajah, Athavan; Boettcher, Shannon W

    2014-12-24

    Protecting Si photocathodes from corrosion is important for developing tandem water-splitting devices operating in basic media. We show that textured commercial Si-pn(+) photovoltaics protected by solution-processed semiconducting/conducting oxides (plausibly suitable for scalable manufacturing) and coupled to thin layers of Ir yield high-performance H2-evolving photocathodes in base. They also serve as excellent test structures to understand corrosion mechanisms and optimize interfacial electrical contacts between various functional layers. Solution-deposited TiO2 protects Si-pn(+) junctions from corrosion for ∼24 h in base, whereas junctions protected by F:SnO2 fail after only 1 h of electrochemical cycling. Interface layers consisting of Ti metal and/or the highly doped F:SnO2 between the Si and TiO2 reduce Si-emitter/oxide/catalyst contact resistance and thus increase fill factor and efficiency. Controlling the oxide thickness led to record photocurrents near 35 mA cm(-2) at 0 V vs RHE and photocathode efficiencies up to 10.9% in the best cells. Degradation, however, was not completely suppressed. We demonstrate that performance degrades by two mechanisms, (1) deposition of impurities onto the thin catalyst layers, even from high-purity base, and (2) catastrophic failure via pinholes in the oxide layers after several days of operation. These results provide insight into the design of hydrogen-evolving photoelectrodes in basic conditions, and highlight challenges.

  1. Water permeability of pigmented waterborne coatings

    NARCIS (Netherlands)

    Donkers, P.A.J.; Huinink, H.P.; Erich, S.J.F.; Reuvers, N.J.W.; Adan, O.C.G.

    2013-01-01

    Coatings are used in a variety of applications. Last decades more and more coating systems are transforming from solvent to waterborne coating systems. In this study the influence of pigments on the water permeability of a waterborne coating system is studied, with special interest in the possible

  2. Radiation cured coatings for fiber optics

    International Nuclear Information System (INIS)

    Ketley, A.D.; Morgan, C.R.

    1978-01-01

    A continuous protective coating is formed on a fiber optic by coating the fiber optic in a bath of a liquid radiation curable composition at a temperature up to 90 0 C and exposing the coated conductor to ultraviolet or high energy ionizing radiation to cure the coating

  3. Hex Chrome Free Coatings for Electronics Overview

    Science.gov (United States)

    Kessel, Kurt

    2013-01-01

    The overall objective of the Hex Chrome Free Coatings for Electronics project is to evaluate and test pretreatment coating systems not containing hexavalent chrome in avionics and electronics housing applications. This objective will be accomplished by testing strong performing coating systems from prior NASA and DoD testing or new coating systems as determined by the stakeholders.

  4. Thermal analysis of silicon carbide coating on a nickel based superalloy substrate and thickness measurement of top layers by lock-in infrared thermography

    Energy Technology Data Exchange (ETDEWEB)

    Ranjit, Shrestha; Kim, Won Tae [Kongju National University, Cheonan (Korea, Republic of)

    2017-04-15

    In this paper, we investigate the capacity of the lock-in infrared thermography technique for the evaluation of non-uniform top layers of a silicon carbide coating with a nickel based superalloy sample. The method utilized a multilayer heat transfer model to analyze the surface temperature response. The modelling of the sample was done in ANSYS. The sample consists of three layers, namely, the metal substrate, bond coat and top coat. A sinusoidal heating at different excitation frequencies was imposed upon the top layer of the sample according to the experimental procedures. The thermal response of the excited surface was recorded, and the phase angle image was computed by Fourier transform using the image processing software, MATLAB and Thermofit Pro. The correlation between the coating thickness and phase angle was established for each excitation frequency. The most appropriate excitation frequency was found to be 0.05 Hz. The method demonstrated potential in the evaluation of coating thickness and it was successfully applied to measure the non-uniform top layers ranging from 0.05 mm to 1 mm with an accuracy of 0.000002 mm to 0.045 mm.

  5. Comparison of additive amount used in spin-coated and roll-coated organic solar cells

    DEFF Research Database (Denmark)

    Cheng, Pei; Lin, Yuze; Zawacka, Natalia Klaudia

    2014-01-01

    All-polymer and polymer/fullerene inverted solar cells were fabricated by spin-coating and roll-coating processes. The spin-coated small-area (0.04 cm(2)) devices were fabricated on indium tin oxide (ITO) coated glass substrates in nitrogen. The roll-coated large-area (1.0 cm(2)) devices were...

  6. Overlay metallic-cermet alloy coating systems

    International Nuclear Information System (INIS)

    Gedwill, M.A.; Glasgow, T.K.; Levine, S.R.

    1982-01-01

    A substrate, such as a turbine blade, vane, or the like, which is subjected to high temperature use is coated with a base coating of an oxide dispersed, metallic alloy (cermet). A top coating of an oxidation, hot corrosion, erosion resistant alloy of nickel, cobalt, or iron is then deposited on the base coating. A heat treatment is used to improve the bonding. The base coating serves as an inhibitor to interdiffusion between the protective top coating and the substrate. Otherwise, the protective top coating would rapidly interact detrimentally with the substrate and degrade by spalling of the protective oxides formed on the outer surface at elevated temperatures

  7. Overlay metallic-cermet alloy coating systems

    Science.gov (United States)

    Gedwill, M. A.; Levine, S. R.; Glasgow, T. K. (Inventor)

    1984-01-01

    A substrate, such as a turbine blade, vane, or the like, which is subjected to high temperature use is coated with a base coating of an oxide dispersed, metallic alloy (cermet). A top coating of an oxidation, hot corrosion, erosion resistant alloy of nickel, cobalt, or iron is then deposited on the base coating. A heat treatment is used to improve the bonding. The base coating serves as an inhibitor to interdiffusion between the protective top coating and the substrate. Otherwise, the protective top coating would rapidly interact detrimentally with the substrate and degrade by spalling of the protective oxides formed on the outer surface at elevated temperatures.

  8. Seal coat binder performance specifications.

    Science.gov (United States)

    2013-11-01

    Need to improve seal coat binder specs: replace empirical tests (penetration, ductility) with : performance-related tests applicable to both : unmodified and modified binders; consider temperatures that cover entire in service : range that are tied t...

  9. Protective coatings for commercial particulates

    DEFF Research Database (Denmark)

    Kindl, B.; Teng, Y.H.; Liu, Y.L.

    1994-01-01

    SiC/Al composites are in large-scale production with Al-Si alloy matrices. The same composites with pure Al or low Si matrices need diffusion barriers on the SiC reinforcement to control the interfacial reaction. The present paper describes various approaches taken to obtain protective coatings...... of alumina and zirconia on SiC particulates by sol-gel techniques. Aqueous and organic precursors have been used. The extent of the reaction, i.e., the Si and Al4C3 content in the matrix, was determined by differential thermal analysis and X-ray diffraction. The reaction rates of some coated particulates...... in liquid Al are decreased by as much as one order of magnitude during the first 15 min of immersion. Pretreatments of the SiC surface, the composition and thickness of the coating interphase and heat treatments of the coated materials have been studied, and are discussed in relation to their effect...

  10. Cementless Hydroxyapatite Coated Hip Prostheses

    Science.gov (United States)

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

    2015-01-01

    More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

  11. Black Sprayable Molecular Adsorber Coating

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of this technology project is to develop, optimize, and flight qualify a black version of the molecular adsorber coating and a conductive version...

  12. Self-stratifying antimicrobial coatings

    NARCIS (Netherlands)

    Yagci, M.B.

    2012-01-01

    Today, antimicrobial polymers/coatings are widely used in various areas, such as biomedical devices, pharmaceuticals, hospital buildings, textiles, food processing, and contact lenses, where sanitation is needed. Such wide application facilities have made antimicrobial materials very attractive for

  13. Smart Coatings for Corrosion Protection

    Science.gov (United States)

    Calle, Luz Marina; Li, Wendy; Buhrow, Jerry W.; Johnsey, Marissa N.

    2016-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

  14. Dielectric coatings on metal substrates

    International Nuclear Information System (INIS)

    Glaros, S.S.; Baker, P.; Milam, D.

    1976-01-01

    Large aperture, beryllium substrate-based mirrors have been used to focus high intensity pulsed laser beams. Finished surfaces have high reflectivity, low wavefront distortion, and high laser damage thresholds. This paper describes the development of a series of metallic coatings, surface finishing techniques, and dielectric overcoatings to meet specified performance requirements. Beryllium substrates were coated with copper, diamond-machined to within 5 micro-inches to final contour, nickel plated, and abrasively figured to final contour. Bond strengths for several bonding processes are presented. Dielectric overcoatings were deposited on finished multimetallic substrates to increase both reflectivity and the damage thresholds. Coatings were deposited using both high and low temperature processes which induce varying stresses in the finished coating substrate system. Data are presented to show the evolution of wavefront distortion, reflectivity, and damage thresholds throughout the many steps involved in fabrication

  15. Cementless Hydroxyapatite Coated Hip Prostheses

    Directory of Open Access Journals (Sweden)

    Antonio Herrera

    2015-01-01

    Full Text Available More than twenty years ago, hydroxyapatite (HA, calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality.

  16. Electrically conductive polymer concrete coatings

    Science.gov (United States)

    Fontana, Jack J.; Elling, David; Reams, Walter

    1990-01-01

    A sprayable electrically conductive polymer concrete coating for vertical d overhead applications is described. The coating is permeable yet has low electrical resistivity (<10 ohm-cm), good bond strength to concrete substrates, and good weatherability. A preferred formulation contains about 60 wt % calcined coke breeze, 40 wt % vinyl ester with 3.5 wt % modified bentonite clay. Such formulations apply evenly and provide enough rigidity for vertical or overhead structures so there is no drip or sag.

  17. Nanocrystalline diamond coatings for machining

    Energy Technology Data Exchange (ETDEWEB)

    Frank, M.; Breidt, D.; Cremer, R. [CemeCon AG, Wuerselen (Germany)

    2007-07-01

    This history of CVD diamond synthesis goes back to the fifties of the last century. However, the scientific and economical potential was only gradually recognized. In the eighties, intensive worldwide research on CVD diamond synthesis and applications was launched. Industrial products, especially diamond-coated cutting tools, were introduced to the market in the middle of the nineties. This article shows the latest developments in this area, which comprises nanocrystalline diamond coating structures. (orig.)

  18. Dry and coating of powders

    International Nuclear Information System (INIS)

    Alonso, M.; Alguacil, F. J.

    1999-01-01

    This paper presents a review on the mixing and coating of powders by dry processes. The reviews surveys fundamental works on mixture characterization (mixing index definitions and sampling techniques), mixing mechanisms and models, segregation with especial emphasis on free-surface segregation, mixing of cohesive powders and interparticle forces, ordered mixing (dry coating) including mechanism, model and applications and mixing equipment selection. (Author) 180 refs

  19. Silicone nanocomposite coatings for fabrics

    Science.gov (United States)

    Eberts, Kenneth (Inventor); Lee, Stein S. (Inventor); Singhal, Amit (Inventor); Ou, Runqing (Inventor)

    2011-01-01

    A silicone based coating for fabrics utilizing dual nanocomposite fillers providing enhanced mechanical and thermal properties to the silicone base. The first filler includes nanoclusters of polydimethylsiloxane (PDMS) and a metal oxide and a second filler of exfoliated clay nanoparticles. The coating is particularly suitable for inflatable fabrics used in several space, military, and consumer applications, including airbags, parachutes, rafts, boat sails, and inflatable shelters.

  20. Coating of silicon pore optics

    DEFF Research Database (Denmark)

    Cooper-Jensen, Carsten P.; Ackermann, M.; Christensen, Finn Erland

    2009-01-01

    For the International X-ray observatory (IXO), a mirror module with an effective area of 3 m2 at 1.25 keV and at least 0.65 m2 at 6 keV has to be realized. To achieve this goal, coated silicon pore optics has been developed over the last years. One of the challenges is to coat the Si plates...

  1. Damage-resistant brittle coatings

    Energy Technology Data Exchange (ETDEWEB)

    Lawn, B.R.; Lee, K.S. [National Inst. of Stand. and Technol., Gaithersburg, MD (United States). Mater. Sci. and Eng. Lab.; Chai, H. [Tel Aviv Univ. (Israel). Faculty of Engineering; Pajares, A. [Universidad de Extremadura, Badajoz (Spain). Dept. de Fisica; Kim, D.K. [Korea Advanced Inst. of Science and Technolgy, Taejon (Korea). Dept. of Materials Science and Engineering; Wuttiphan, S. [National Metal and Materials Technology Center, Bangkok (Thailand); Peterson, I.M. [Corning Inc., NY (United States); Hu Xiaozhi [Western Australia Univ., Nedlands, WA (Australia). Dept. of Mechanical and Materials Engineering

    2000-11-01

    Laminate structures consisting of hard, brittle coatings and soft, tough substrates are important in a wide variety of engineering applications, biological structures, and traditional pottery. In this study the authors introduce a new approach to the design of damage-resistant brittle coatings, based on a combination of new and existing relations for crack initiation in well-defined contact-induced stress fields. (orig.)

  2. Corrosion resistant neutron absorbing coatings

    Science.gov (United States)

    Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  3. Material Science Smart Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, A. I. [Univ. of Nebraska Medical Center, Omaha, NE (United States); Sabirianov, R. F. [Univ. of Nebraska Medical Center, Omaha, NE (United States); Namavar, Fereydoon [Univ. of Nebraska Medical Center, Omaha, NE (United States)

    2014-07-01

    The contribution of electrostatic interactions to the free energy of binding between model protein and a ceramic implant surface in the aqueous solvent, considered in the framework of the nonlocal electrostatic model, is calculated as a function of the implant low-frequency dielectric constant. We show that the existence of a dynamically ordered (low-dielectric) interfacial solvent layer at the protein-solvent and ceramic-solvent interface markedly increases charging energy of the protein and ceramic implant, and consequently makes the electrostatic contribution to the protein-ceramic binding energy more favorable (attractive). Our analysis shows that the corresponding electrostatic energy between protein and oxide ceramics depends nonmonotonically on the dielectric constant of ceramic, εC. Obtained results indicate that protein can attract electrostatically to the surface if ceramic material has a moderate εC below or about 35 (in particularly ZrO2 or Ta2O5). This is in contrast to classical (local) consideration of the solvent, which demonstrates an unfavorable electrostatic interaction of protein with typical metal oxide ceramic materials (εC>10). Thus, a solid implant coated by combining oxide ceramic with a reduced dielectric constant can be beneficial to strengthen the electrostatic binding of the protein-implant complex.

  4. Silane based coating of aluminium mold

    DEFF Research Database (Denmark)

    2013-01-01

    having at least one closed cavity is provided, at least one surface of the at least one cavity being an aluminium surface coated with a silane based coating layer. The silane based anti-stiction coating improves the anti-stiction properties of the mold which may allow for molding and demolding...... of structures which would otherwise be difficult to mold. The resistance of the coated aluminium mold is significantly improved by applying a silane-based coating layer....

  5. Switchable antifouling coatings and uses thereof

    Science.gov (United States)

    Denton, Michele L. Baca; Dirk, Shawn M.; Johnson, Ross Stefan

    2017-02-28

    The present invention relates to antifouling coatings capable of being switched by using heat or ultraviolet light. Prior to switching, the coating includes an onium cation component having antimicrobial and antibacterial properties. Upon switching, the coating is converted to a conjugated polymer state, and the cationic component is released with any adsorbed biofilm layer. Thus, the coatings herein have switchable and releasable properties. Methods of making and using such coatings are also described.

  6. Graphene: corrosion-inhibiting coating.

    Science.gov (United States)

    Prasai, Dhiraj; Tuberquia, Juan Carlos; Harl, Robert R; Jennings, G Kane; Rogers, Bridget R; Bolotin, Kirill I

    2012-02-28

    We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na(2)SO(4) solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corrodes 20 times slower while nickel surfaces coated with four layers of mechanically transferred graphene corrode 4 times slower than bare nickel. These findings establish graphene as the thinnest known corrosion-protecting coating.

  7. Polymeric Coatings for Combating Biocorrosion

    Science.gov (United States)

    Guo, Jing; Yuan, Shaojun; Jiang, Wei; Lv, Li; Liang, Bin; Pehkonen, Simo O.

    2018-03-01

    Biocorrosion has been considered as big trouble in many industries and marine environments due to causing great economic loss. The main disadvantages of present approaches to prevent corrosion include being limited by environmental factors, being expensive, inapplicable to field, and sometimes inefficient. Studies show that polymer coatings with anti-corrosion and anti-microbial properties have been widely accepted as a novel and effective approach to preventbiocorrosion. The main purpose of this review is to summarize up the progressive status of polymer coatings used for combating microbially-induced corrosion. Polymers used to synthesize protective coatings are generally divided into three categories: i) traditional polymers incorporated with biocides, ii) antibacterial polymers containing quaternary ammonium compounds, and iii) conductive polymers. The strategies to synthesize polymer coatings resort mainly to grafting anti-bacterial polymers from the metal substrate surface using novel surface-functionalization approaches, such as free radical polymerization, chemically oxidative polymerization and surface-initiated atom transfer radical polymerization, as opposed to the traditional approaches of dip coating or spin coating.

  8. Electron beam-cured coating

    International Nuclear Information System (INIS)

    Kishi, Naoyuki

    1976-01-01

    The method for hardening coatings by the irradiation with electron beams is reviewed. The report is divided into seven parts, namely 1) general description and characteristics of electron beam-cured coating, 2) radiation sources of curing, 3) hardening conditions and reaction behaviour, 4) uses and advantages, 5) latest trends of the industry, 6) practice in the field of construction materials, and 7) economy. The primary characteristics of the electron beam hardening is that graft reaction takes place between base resin and coating to produce strong adhesive coating without any pretreatment. A variety of base resins are developed. High class esters of acrylic acid monomers and methacrylic acid monomers are mainly used as dilutants recently. At present, scanning type accelerators are used, but the practical application of the system producing electron beam of curtain type is expected. The dose rate dependence, the repetitive irradiation and the irradiation atmosphere are briefly described. The filed patent applications on the electron beam hardening were analyzed by the officer of Japan Patent Agency. The production lines for coatings by the electron beam hardening in the world are listed. In the electron beam-cured coating, fifty percent of given energy is consumed effectively for the electron beam hardening, and the solvents discharged from ovens and polluting atmosphere are not used, because the paints of high solid type is used. The running costs of the electron beam process are one sixth of the thermal oven process. (Iwakiri, K.)

  9. Diamond-like carbon coatings with zirconium-containing interlayers for orthopedic implants.

    Science.gov (United States)

    Choudhury, Dipankar; Lackner, Juergen; Fleming, Robert A; Goss, Josh; Chen, Jingyi; Zou, Min

    2017-04-01

    Six types of diamond-like carbon (DLC) coatings with zirconium (Zr)-containing interlayers on titanium alloy (Ti-6Al-4V) were investigated for improving the biotribological performance of orthopedic implants. The coatings consist of three layers: above the substrate a layer stack of 32 alternating Zr and ZrN sublayers (Zr:ZrN), followed by a layer comprised of Zr and DLC (Zr:DLC), and finally a N-doped DLC layer. The Zr:ZrN layer is designed for increasing load carrying capacity and corrosion resistance; the Zr:DLC layer is for gradual transition of stress, thus enhancing layer adhesion; and the N-doped DLC layer is for decreasing friction, squeaking noises and wear. Biotribological experiments were performed in simulated body fluid employing a ball-on-disc contact with a Si 3 N 4 ball and a rotational oscillating motion to mimic hip motion in terms of gait angle, dynamic contact pressures, speed and body temperature. The results showed that the Zr:DLC layer has a substantial influence on eliminating delamination of the DLC from the substrates. The DLC/Si 3 N 4 pairs significantly reduced friction coefficient, squeaking noise and wear of both the Si 3 N 4 balls and the discs compared to those of the Ti-6Al-4V/Si 3 N 4 pair after testing for a duration that is equivalent to one year of hip motion in vivo. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Development of Clay Tile Coatings for Steep-Sloped Cool Roofs

    Directory of Open Access Journals (Sweden)

    Lucia Brinchi

    2013-07-01

    Full Text Available Most of the pitched roofs of existing buildings in Europe are covered by non-white roofing products, e.g., clay tiles. Typical, cost effective, cool roof solutions are not applicable to these buildings due to important constraints deriving from: (i the owners of homes with roofs visible from the ground level; (ii the regulation about the preservation of the historic architecture and the minimization of the visual environment impact, in particular in historic centers. In this perspective, the present paper deals with the development of high reflective coatings with the purpose to elaborate “cool” tiles with the same visual appearance of traditional tiles for application to historic buildings. Integrated experimental analyses of reflectance, emittance, and superficial temperature were carried out. Deep analysis of the reflectance spectra is undertaken to evaluate the effect of different mineral pigments, binders, and an engobe basecoat. Two tile typologies are investigated: substrate-basecoat-topcoat three-layer tile and substrate-topcoat two-layer tile. The main results show that the developed coatings are able to increase the overall solar reflectance by more than 20% with acceptable visual appearance, suitable for application in historic buildings. Additionally, the effect of a substrate engobe layer allows some further contribution to the increase of the overall reflectance characteristics.

  11. Analysis of Capillary Coating Die Flow in an Optical Fiber Coating Applicator

    OpenAIRE

    Kyoungjin Kim

    2011-01-01

    Viscous heating becomes significant in the high speed resin coating process of glass fibers for optical fiber manufacturing. This study focuses on the coating resin flows inside the capillary coating die of optical fiber coating applicator and they are numerically simulated to examine the effects of viscous heating and subsequent temperature increase in coating resin. Resin flows are driven by fast moving glass fiber and the pressurization at the coating die inlet, while ...

  12. Pin Wire Coating Trip Report

    International Nuclear Information System (INIS)

    Spellman, G P

    2004-01-01

    A meeting to discuss the current pin wire coating problems was held at the Reynolds plant in Los Angeles on 2MAR04. The attendance list for Reynolds personnel is attached. there was an initial presentation which gave a brief history and the current status of pin wire coating at Reynolds. There was a presentation by Lori Primus on the requirements and issues for the coating. There was a presentation by Jim Smith of LANL on the chemistry and to some extent process development done to date. There was a long session covering what steps should be taken in the short term and, to a lesser extent, the long term. The coating currently being used is a blend of two polymers, polyethersulfone and polyparabanic acid (PPA) and some TiO2 filler. This system was accepted and put into production when the pin wire coating was outsourced to another company in 1974. When that company no longer was interested, the wire coating was brought in-house to Reynolds. At that time polyparabanic acid was actually a commercial product available from Exxon under the trade name Tradlon. However, it appears that the material used at Reynolds was synthesized locally. Also, it appears that a single large batch was synthesized in that time period and used up to 1997 when the supply ran out. The reason for the inclusion of TiO2 is not known although it does act as a rheological thickener. However, a more controlled thickening can be obtained with materials such as fumed silica. This material would have less likelihood of causing point imperfections in the coatings. Also, the mixing technique being used for all stages of the process is a relatively low shear ball mill process and the author recommends a high shear process such as a three roll paint mill, at least for the final mixing. Since solvent is added to the powder at Reynolds, it may be that they need to have the paint mill there

  13. Advanced Marine Coatings for Naval Vessels - Phase 1. Antifouling and Fouling Release Coatings

    National Research Council Canada - National Science Library

    McCarthy, Gregory

    2003-01-01

    ... in combinatorial materials chemistry high-throughput discovery and evaluation methodology. The protective coatings application being addressed is environmentally compliant antifouling and fouling release coating for Navy ships...

  14. Properties of SrBi sub 2 Nb sub 2 O sub 9 thin films on Pt-coated Si

    CERN Document Server

    Avila, R E; Martin, V D C; Fernandez, L M; Sylvester, G S; Retuert, P J; Gramsch, E

    2002-01-01

    SrBi sub 2 Nb sub 2 O sub 9 powders and thin films, on Pt-coated Si, were synthesised by the sol-gel method. Three-layer thin films appear homogeneous down to the 100 nm scale, polycrystalline in the tetragonal Aurivillius phase, at a average thickness of 40 nm per layer. The index of refraction at the center of the visible range increases with the sintering temperature from roughly 2.1 (at 400 Centigrade) to 2.5 (at 700 Centigrade). The expression n sup 2 -1 increases linearly with the relative density of the thin films, in similar fashion as previous studies in PbTiO sub 3 thin films. The dielectric constant in quasistatic and high frequency (1 MHz) modes, is between 160 and 230. (Author)

  15. Properties of SrBi2Nb2O9 thin films on Pt-coated Si

    International Nuclear Information System (INIS)

    Avila, R.E.; Navarro, P.O.; Martin, V. del C.; Fernandez, L.M.; Sylvester, G.; Retuert, P.J.; Gramsch, E.

    2002-01-01

    SrBi 2 Nb 2 O 9 powders and thin films, on Pt-coated Si, were synthesised by the sol-gel method. Three-layer thin films appear homogeneous down to the 100 nm scale, polycrystalline in the tetragonal Aurivillius phase, at a average thickness of 40 nm per layer. The index of refraction at the center of the visible range increases with the sintering temperature from roughly 2.1 (at 400 Centigrade) to 2.5 (at 700 Centigrade). The expression n 2 -1 increases linearly with the relative density of the thin films, in similar fashion as previous studies in PbTiO 3 thin films. The dielectric constant in quasistatic and high frequency (1 MHz) modes, is between 160 and 230. (Author)

  16. Process for preparing coating materials

    International Nuclear Information System (INIS)

    Ryoke, Hideyasu; Kobayashi, Juichi; Kobayashi, Kei.

    1972-01-01

    A coating material curable with ionizing radiations or ultraviolet radiation can be prepared by reacting a compound (A) having one OH group and at least one α,β-ethylenic or allyl group with a polyisocyanate. (A) is a diester of a dicarboxylic acid. One of the ester groups may have a terminal α,β-ethylenic or allyl group and the other contains one OH and one α,β-ethylenic or allyl group. (A) is reacted with a polyisocyanate to yield an urethane. The latter may be diluted with a vinyl monomer. When exposed to a radiation, the coating material cures to give a film excellent in adhesion, impact strength and resistances to pollution, water and solvents. Dose of the ionizing radiation (α-, β-, γ-rays, electron beams) is 0.2-20 Mrad. In one example, 116 parts of 2-hydroxyethyl acrylate was reacted with 148 parts of phthalic anhydride and 142 parts of glycidyl methacrylate to give (A). (A) was reacted with 87 parts of tolylenediisocyanate. A metallic panel was coated with the coating material and cured with electron beams (5 Mrad). Pencil hardness was H, and gel fraction measured in acetone was above 97%. The coating was excellent in resistances to solvent and chemicals, impact strength and adhesion. (Kaichi, S.)

  17. Chromate conversion coatings and their current application

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-04-01

    Full Text Available This paper describes formation, composition and possible production technologies of application chromate coatings. Summation of common examples of applications of these coatings in corrosion protection of metals and alloys is provided. Individual chromate coatings are divided by their dominant anions either with CrVI or CrIII. Restrictions of chromate coatings with dominantly CrVI and related toxicity of hexavalent chromium is discussed in detail. In conclusion, examples of both chromium and other, alternative coatings are summed up. Application of these coatings as a protection for concrete hot-dip galvanized reinforcement is also reviewed.

  18. Radiation curable compositions useful as transfer coatings

    International Nuclear Information System (INIS)

    McCarty, W.H.; Nagy, F.A.; Guarino, J.P.

    1983-01-01

    The invention is on a method for applying a coating to a thin porous substrate and reducing absorption of the coating into the substrate by applying a radiation-curable composition to a carrying web; the radiation-curable coating composition having a crosslink density of 0.02 to about 1.0 determined by calculation of the gram moles of branch points per 100 grams of uncured coating, and a glass transition temperature of the radiation cured coating within the approximate range of -80 degrees to +100 degrees C. The carrying web being of a nature such that the coating composition, when cured, will not adhere to its surface

  19. Bonding mechanisms in spot welded three layer combinations

    DEFF Research Database (Denmark)

    Moghadam, Marcel; Tiedje, Niels Skat; Seyyedian Choobi, Mahsa

    2016-01-01

    this interface. It has been shown previously that such a joint can reach relatively high strength resulting in plug failure in tensileshear testing. Additional strength due to these bonding mechanisms is also obtained in common spot welds in the so-called corona band around the weld nugget.......The strength of a spot weld generally stems from fusion bonding of the metal layers, but other solid state bonding mechanisms also contribute to the overall strength. Metallographic analyses are presented to identify the phases formed near and across the weld interfaces and to identify...... the occurring bonding mechanisms. When welding a combination of three galvanized steel layers where one outer layer is a thin low-carbon steel it is a common challenge to obtain nugget penetration into the thin low-carbon steel. It therefore happens in real production that no nugget is formed across...

  20. Mixed zirconia calcium phosphate coatings for dental implants: Tailoring coating stability and bioactivity potential

    International Nuclear Information System (INIS)

    Pardun, Karoline; Treccani, Laura; Volkmann, Eike; Streckbein, Philipp; Heiss, Christian; Destri, Giovanni Li; Marletta, Giovanni; Rezwan, Kurosch

    2015-01-01

    Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. - Highlights: • Different ratios of zirconia (TZ) and calcium phosphate (CP) were deposited on zirconia substrates. • Enhancement of TZ content in mixed coatings increased coating stability. • Enhancement of CP content in mixed coatings increased bioactivity. • All tested coating compositions were non-toxic