Plasma Spray-Physical Vapor Deposition (PS-PVD) of Ceramics for Protective Coatings

Science.gov (United States)

Harder, Bryan J.; Zhu, Dongming

2011-01-01

In order to generate advanced multilayer thermal and environmental protection systems, a new deposition process is needed to bridge the gap between conventional plasma spray, which produces relatively thick coatings on the order of 125-250 microns, and conventional vapor phase processes such as electron beam physical vapor deposition (EB-PVD) which are limited by relatively slow deposition rates, high investment costs, and coating material vapor pressure requirements. The use of Plasma Spray - Physical Vapor Deposition (PS-PVD) processing fills this gap and allows thin (deposited and multilayer coatings of less than 100 microns to be generated with the flexibility to tailor microstructures by changing processing conditions. Coatings of yttria-stabilized zirconia (YSZ) were applied to NiCrAlY bond coated superalloy substrates using the PS-PVD coater at NASA Glenn Research Center. A design-of-experiments was used to examine the effects of process variables (Ar/He plasma gas ratio, the total plasma gas flow, and the torch current) on chamber pressure and torch power. Coating thickness, phase and microstructure were evaluated for each set of deposition conditions. Low chamber pressures and high power were shown to increase coating thickness and create columnar-like structures. Likewise, high chamber pressures and low power had lower growth rates, but resulted in flatter, more homogeneous layers

Ab initio study of the effects of thin CsI coatings on the work function of graphite cathodes

Science.gov (United States)

Vlahos, Vasilios; Booske, John H.; Morgan, Dane

2007-10-01

Cesium-iodide (CsI)-coated graphite cathodes are promising electron sources for high power microwave generators, but the mechanism driving the improved emission is not well understood. Therefore, an ab initio modeling investigation on the effects of thin CsI coatings on graphite has been carried out. It is demonstrated that the CsI coatings reduce the work function of the system significantly through a mechanism of induced dipoles. The results suggest that work function modification is a major contribution to the improved emission seen when CsI coatings are applied to C.

Vapor phase coatings of metals and organics for laser fusion target applications

International Nuclear Information System (INIS)

Simonsic, G.A.; Powell, B.W.

Techniques for applying a variety of metal and organic coatings to 50- to 500 μm diameter glass micro-balloons are discussed. Coating thicknesses vary from 1- to 10 μm. Physical vapor deposition (PVD), chemical vapor deposition (CVD), and electrolytic and electroless plating are some of the techniques being evaluated for metal deposition. PVD and glow discharge polymerization are being used for the application of organic coatings. (U.S.)

21 CFR 172.275 - Synthetic paraffin and succinic derivatives.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Synthetic paraffin and succinic derivatives. 172... FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.275 Synthetic paraffin and succinic derivatives. Synthetic paraffin and succinic derivatives identified in this section may be safely...

Nylon filament coated with paraffin for intraluminal permanent middle cerebral artery occlusion in rats.

Science.gov (United States)

Zuo, Xia-Lin; Wu, Ping; Ji, Ai-Min

2012-06-21

A variety of intraluminal nylon filament has been used in rat middle cerebral artery occlusion (MCAO) models. However the lesion extent and its reproducibility vary among laboratories. The properties of nylon filament play a part of reasons for these variations. In the present study, we used paraffin-coated nylon filament for rat MCAO model, tested the effects and advanced improvement for making the rat MCAO. Forty male Sprague-Dawley (SD) rats were randomized into two groups, MCAO with traditional uncoated nylon filament (uMCAO) and MCAO with paraffin-coated nylon filament (cMCAO), three rats as normal group and sham group respectively. Assessment included mortality rates, model success rates, neurological deficit evaluation, and infarct volume. The study showed two rats died in uMCAO group, no rat died in cMCAO group within the 12h. The model success rate of uMCAO was 100%, while the uMCAO group was 55% (n=20, two died within 12h, seven rats were excluded as the brain slices showed no TTC staining due to subarachanoid hemorrhage). Neurological evaluation demonstrated group cMCAO had more worse neurological outcomes than group uMCAO, and the difference was statistically signification (pparaffin-coated nylon filament intraluminal occlusion provide better occlusion of middle cerebral artery than the uncoated nylon filament, improve the consistent of model, and raise the success rate to reduce the number of experimental animals. These positive results are much encouraging and interesting. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Paraffin/expanded graphite phase change composites with enhanced thermal conductivity prepared by implanted β-SiC nanowires with chemical vapor deposition method

Science.gov (United States)

Yin, Zhaoyu; Zhang, Xiaoguang; Huang, Zhaohui; Liu, Silin; Zhang, Weiyi; Liu, Yan'gai; Wu, Xiaowen; Fang, Minghao; Min, Xin

2018-02-01

Expanded graphite/β-SiC nanowires composites (ESNC) were prepared through chemical vapor deposition, and paraffin/expanded graphite/β-SiC nanowires composites (PESNC) were made through vacuum impregnation to overcome liquid leakage during phase transition and enhance the thermal conductivity of paraffin. Fourier transform infrared spectroscopy showed no chemical interactions between the paraffin and ESNC. Differential scanning calorimetry estimated the temperature and latent heat of PESNC during melting to 45.73 °C and 124.31 J g-1, respectively. The respective values of these quantities during freezing were recorded as 48.93 °C and 124.14 J g-1. The thermal conductivity of PESNC was estimated to 0.75 W mK-1, which was 3.26-folds that of pure paraffin (0.23 W mK-1). PESNC perfectly maintained its phase transition after 200 melting-freezing cycles. The resulting ideal thermal conductivity, good chemical stability, thermal properties and thermal reliability of PESNC are promising for use in energy efficient buildings and solar energy systems.

PARAFFIN SEPARATION VACUUM DISTILLATION

Directory of Open Access Journals (Sweden)

Zaid A. Abdulrahman

2013-05-01

Full Text Available Simulated column performance curves were constructed for existing paraffin separation vacuum distillation column in LAB plant (Arab Detergent Company/Baiji-Iraq. The variables considered in this study are the thermodynamic model option, top vacuum pressure, top and bottom temperatures, feed temperature, feed composition & reflux ratio. Also simulated columns profiles for the temperature, vapor & liquid flow rates composition were constructed. Four different thermodynamic model options (SRK, TSRK, PR, and ESSO were used, affecting the results within 1-25% variation for the most cases.The simulated results show that about 2% to 8 % of paraffin (C10, C11, C12, & C13 present at the bottom stream which may cause a problem in the LAB plant. The major variations were noticed for the top temperature & the  paraffin weight fractions at bottom section with top vacuum pressure. The bottom temperature above 240 oC is not recommended because the total bottom flow rate decreases sharply, where as  the weight fraction of paraffins decrease slightly. The study gives evidence about a successful simulation with CHEMCAD

Physically vapor deposited coatings on tools: performance and wear phenomena

International Nuclear Information System (INIS)

Koenig, W.; Fritsch, R.; Kammermeier, D.

1991-01-01

Coatings produced by physical vapor deposition (PVD) enhance the performance of tools for a broad variety of production processes. In addition to TiN, nowadays (Ti,Al)N and Ti(C,N) coated tools are available. This gives the opportunity to compare the performance of different coatings under identical machining conditions and to evaluate causes and phenomena of wear. TiN, (Ti,Al)N and Ti(C,N) coatings on high speed steel (HSS) show different performances in milling and turning of heat treated steel. The thermal and frictional properties of the coating materials affect the structure, the thickness and the flow of the chips, the contact area on the rake face and the tool life. Model tests show the influence of internal cooling and the thermal conductivity of coated HSS inserts. TiN and (Ti,Zr)N PVD coatings on cemented carbides were examined in interrupted turning and in milling of heat treated steel. Experimental results show a significant influence of typical time-temperature cycles of PVD and chemical vapor deposition (CVD) coating processes on the physical data and on the performance of the substrates. PVD coatings increase tool life, especially towards lower cutting speeds into ranges which cannot be applied with CVD coatings. The reason for this is the superior toughness of the PVD coated carbide. The combination of tough, micrograin carbide and PVD coating even enables broaching of case hardened sliding gears at a cutting speed of 66 m min -1 . (orig.)

Chemical vapor deposition: A technique for applying protective coatings

Energy Technology Data Exchange (ETDEWEB)

Wallace, T.C. Sr.; Bowman, M.G.

1979-01-01

Chemical vapor deposition is discussed as a technique for applying coatings for materials protection in energy systems. The fundamentals of the process are emphasized in order to establish a basis for understanding the relative advantages and limitations of the technique. Several examples of the successful application of CVD coating are described. 31 refs., and 18 figs.

Functional possibilities of organosilicon coatings on the surface of CsI-based scintillators

CERN Document Server

Andryustchenko, L A; Goriletsky, V I; Zaslavsky, B G; Zosim, D I; Charkina, T A; Trefilova, L N; Renker, D; Ritt, S; Mzhavia, D A

2002-01-01

It has been shown that a thin film (15+-5 mu m) based on organosilicon coating applied to all surface of CsI and CsI(Tl) scintillators excluding the output window, can combine the following functions: (1) covering from atmospheric effects; (2) scintillation light convertor of luminescence towards the region of higher spectral sensitivity of the photoreceiver and (3) ancillary surface for performance of operations on changing the light collection coefficient without the risk to exceed limited size tolerations. Wavelength-shifting coating effect on radiation hardness of pure CsI is discussed. After irradiation a new absorption bands appear in the range 250-300 nm mainly. So, contrary to the 310 nm emission, the energy losses for converted light remain the same.

Oxygen Barrier Coating Deposited by Novel Plasma-enhanced Chemical Vapor Deposition

DEFF Research Database (Denmark)

Jiang, Juan; Benter, M.; Taboryski, Rafael Jozef

2010-01-01

We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source. This confi......We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source...... effect of single-layer coatings deposited under different reaction conditions was studied. The coating thickness and the carbon content in the coatings were found to be the critical parameters for the barrier property. The novel barrier coating was applied on different polymeric materials...

Acetone vapor sensing using a vertical cavity surface emitting laser diode coated with polystyrene

DEFF Research Database (Denmark)

Ansbæk, Thor; Nielsen, Claus Højgaard; Larsen, Niels Bent

2009-01-01

We report theoretical and experimental on a new vapor sensor, using a single-mode vertical-cavity surface-emitting laser (VCSEL) coated with a polymer sensor coating, which can detect acetone vapor at a volume fraction of 2.5%. The sensor provides the advantage of standard packaging, small form...

Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

Energy Technology Data Exchange (ETDEWEB)

Xu, Zhenhua, E-mail: zhxuciac@163.com [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Dai, Jianwei [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Niu, Jing [Shenyang Liming Aero-engine (Group) Corporation Ltd., Institute of Metallurgical Technology, Technical Center, Shengyang 110043 (China); Li, Na; Huang, Guanghong; He, Limin [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China)

2014-12-25

Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y{sub 2}O{sub 3}-stabilized-ZrO{sub 2} (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs.

Chemically vapor deposited coatings for multibarrier containment of nuclear wastes

International Nuclear Information System (INIS)

Rusin, J.M.; Shade, J.W.; Kidd, R.W.; Browning, M.F.

1981-01-01

Chemical vapor deposition (CVD) was selected as a feasible method to coat ceramic cores, since the technology has previously been demonstrated for high-temperature gas-cooled reactor (HTGR) fuel particles. CVD coatings, including SiC, PyC (pyrolytic carbon), SiO 2 , and Al 2 O 3 were studied. This paper will discuss the development and characterization of PyC and Al 2 O 3 CVD coatings on supercalcine cores. Coatings were applied to 2 mm particles in either fluidized or vibrating beds. The PyC coating was deposited in a fluidized bed with ZrO 2 diluent from C 2 H 2 at temperatures between 1100 and 1200 0 C. The Al 2 O 3 coatings were deposited in a vibrated bed by a two-stage process to minimize loss of PyC during the overcoating operation. This process involved applying 10 μm of Al 2 O 3 using water vapor hydrolysis of AlCl 3 and then switching to the more surface-controlled hydrolysis via the H 2 + CO 2 reaction (3CO 2 + 3H 2 + 2AlCl 3 = Al 2 O 3 + 6HCl + 3CO). Typically, 50 to 80 μm Al 2 O 3 coatings were applied over 30 to 40 μm PyC coatings. The coatings were evaluated by metallographic examination, PyC oxidation tests, and leach resistance. After air oxidation for 100 hours at 750 0 C, the duplex PyC/Al 2 O 3 coated particles exhibited a weight loss of 0.01 percent. Leach resistance is being determined for temperatures from 50 to 150 0 C in various solutions. Typical results are given for selected ions. The leach resistance of supercalcine cores is significantly improved by the application of PyC and/or Al 2 O 3 coatings

Direct Vapor Growth of Perovskite CsPbBr3 Nanoplate Electroluminescence Devices.

Science.gov (United States)

Hu, Xuelu; Zhou, Hong; Jiang, Zhenyu; Wang, Xiao; Yuan, Shuangping; Lan, Jianyue; Fu, Yongping; Zhang, Xuehong; Zheng, Weihao; Wang, Xiaoxia; Zhu, Xiaoli; Liao, Lei; Xu, Gengzhao; Jin, Song; Pan, Anlian

2017-10-24

Metal halide perovskite nanostructures hold great promises as nanoscale light sources for integrated photonics due to their excellent optoelectronic properties. However, it remains a great challenge to fabricate halide perovskite nanodevices using traditional lithographic methods because the halide perovskites can be dissolved in polar solvents that are required in the traditional device fabrication process. Herein, we report single CsPbBr 3 nanoplate electroluminescence (EL) devices fabricated by directly growing CsPbBr 3 nanoplates on prepatterned indium tin oxide (ITO) electrodes via a vapor-phase deposition. Bright EL occurs in the region near the negatively biased contact, with a turn-on voltage of ∼3 V, a narrow full width at half-maximum of 22 nm, and an external quantum efficiency of ∼0.2%. Moreover, through scanning photocurrent microscopy and surface electrostatic potential measurements, we found that the formation of ITO/p-type CsPbBr 3 Schottky barriers with highly efficient carrier injection is essential in realizing the EL. The formation of the ITO/p-type CsPbBr 3 Schottky diode is also confirmed by the corresponding transistor characteristics. The achievement of EL nanodevices enabled by directly grown perovskite nanostructures could find applications in on-chip integrated photonics circuits and systems.

Development of Cr cold spray–coated fuel cladding with enhanced accident tolerance

Directory of Open Access Journals (Sweden)

Martin Ševeček

2018-03-01

Full Text Available Accident-tolerant fuels (ATFs are currently of high interest to researchers in the nuclear industry and in governmental and international organizations. One widely studied accident-tolerant fuel concept is multilayer cladding (also known as coated cladding. This concept is based on a traditional Zr-based alloy (Zircaloy-4, M5, E110, ZIRLO etc. serving as a substrate. Different protective materials are applied to the substrate surface by various techniques, thus enhancing the accident tolerance of the fuel. This study focuses on the results of testing of Zircaloy-4 coated with pure chromium metal using the cold spray (CS technique. In comparison with other deposition methods, e.g., Physical vapor deposition (PVD, laser coating, or Chemical vapor deposition techniques (CVD, the CS technique is more cost efficient due to lower energy consumption and high deposition rates, making it more suitable for industry-scale production. The Cr-coated samples were tested at different conditions (500°C steam, 1200°C steam, and Pressurized water reactor (PWR pressurization test and were precharacterized and postcharacterized by various techniques, such as scanning electron microscopy, Energy-dispersive X-ray spectroscopy (EDX, or nanoindentation; results are discussed. Results of the steady-state fuel performance simulations using the Bison code predicted the concept's feasibility. It is concluded that CS Cr coating has high potential benefits but requires further optimization and out-of-pile and in-pile testing. Keywords: Accident-Tolerant Fuel, Chromium, Cladding, Coating, Cold Spray, Nuclear Fuel

Processing-structure-property relationships in electron beam physical vapor deposited yttria stabilized zirconia coatings

International Nuclear Information System (INIS)

Rao, D. Srinivasa; Valleti, Krishna; Joshi, S. V.; Janardhan, G. Ranga

2011-01-01

The physical and mechanical properties of yttria stabilized zirconia (YSZ) coatings deposited by the electron beam physical vapor deposition technique have been investigated by varying the key process variables such as vapor incidence angle and sample rotation speed. The tetragonal zirconia coatings formed under varying process conditions employed were found to have widely different surface and cross-sectional morphologies. The porosity, phase composition, planar orientation, hardness, adhesion, and surface residual stresses in the coated specimens were comprehensively evaluated to develop a correlation with the process variables. Under transverse scratch test conditions, the YSZ coatings exhibited two different crack formation modes, depending on the magnitude of residual stress. The influence of processing conditions on the coating deposition rate, column orientation angle, and adhesion strength has been established. Key relationships between porosity, hardness, and adhesion are also presented.

Surface chemical analysis and ab initio investigations of CsI coated C fiber cathodes for high power microwave sources

Science.gov (United States)

Vlahos, Vasilios; Morgan, Dane; LaCour, Matthew; Golby, Ken; Shiffler, Don; Booske, John H.

2010-02-01

CsI coated C fiber cathodes are promising electron emitters utilized in field emission applications. Ab initio calculations, in conjunction with experimental investigations on CsI-spray coated C fiber cathodes, were performed in order to better understand the origin of the low turn-on E-field obtained, as compared to uncoated C fibers. One possible mechanism for lowering the turn-on E-field is surface dipole layers reducing the work function. Ab initio modeling revealed that surface monolayers of Cs, CsI, Cs2O, and CsO are all capable of producing low work function C fiber cathodes (1 eV<Φ<1.5 eV), yielding a reduction in the turn-on E-field by as much as ten times, when compared to the bare fiber. Although a CsI-containing aqueous solution is spray deposited on the C fiber surface, energy dispersive x-ray spectroscopy and scanning auger microscopy measurements show coabsorption of Cs and I into the fiber interior and Cs and O on the fiber surface, with no surface I. It is therefore proposed that a cesium oxide (CsxOy) surface coating is responsible, at least in part, for the low turn E-field and superior emission characteristics of this type of fiber cathode. This CsxOy layer could be formed during preconditioning heating. CsxOy surface layers cannot only lower the fiber work function by the formation of surface dipoles (if they are thin enough) but may also enhance surface emission through their ability to emit secondary electrons due to a process of grazing electron impact. These multiple electron emission processes may explain the reported 10-100 fold reduction in the turn-on E-field of coated C fibers.

Study of compoisiton of saturated vapor of MF-CuF2 systems, where M=K, Rb, Cs

International Nuclear Information System (INIS)

Morozov, I.V.; Korenev, Yu.M.

1993-01-01

Investigation into composition of saturated vapor of MF-CuF 2 systems where M=K, Rb, Cs is conducted using high-temperature mass-spectrometry. Existence of MCuF 3 molecules in gas phase is determined. MCuF 3(r) dissociation enthalpies are calculated using the first law-of thermodynamics and are compared with theoretically determined values. Value Δ D G 0 944 (CsCuF 3(r) =105.6±6.3 kj/mol is determined

Modelling of an experiment INSS and paraffin moderator at JINR

International Nuclear Information System (INIS)

Goyal, Uttam; Kumawat, Harphool; Kumar, V.; Barashenkov, V.S.

2002-01-01

Intense neutron spallation source (INSS) described elsewhere is studied with paraffin moderator using the Dubna cascade code. For the present study paraffin is assumed having configuration corresponding to C 22 H 46 with density = 0.87 g/cm 3 6 cm thickness of paraffin is coated around the Pb-spallation target of size ΦxL = 8x20 cm 2 and proton beam with E lab = 1 GeV is allowed to collide at the center of the left face

Thermal ionization and plasma state of high temperature vapor of UO2, Cs, and Na: Effect on the heat and radiation transport properties of the vapor phase

International Nuclear Information System (INIS)

Karow, H.U.

1979-01-01

The paper deals with the question how far the thermophysical state and the convective and radiative heat transport properties of vaporized reactor core materials are affected by the thermal ionization existing in the actual vapor state. The materials under consideration here are: nuclear oxide fuel (UO 2 ), Na (as the LMFBR coolant material), and Cs (alkaline fission product, partly retained in the fuel of the core zone). (orig./RW) [de

Hard X-ray photoelectron spectroscopy study for transport behavior of CsI in heating test simulating a BWR severe accident condition: Chemical effects of boron vapors

Energy Technology Data Exchange (ETDEWEB)

Okane, T., E-mail: okanet@spring8.or.jp [Quantum Beam Science Center, Japan Atomic Energy Agency, 1-1-1 Kouto, Sayo-cho, Hyogo, 679-5148 (Japan); Kobata, M. [Quantum Beam Science Center, Japan Atomic Energy Agency, 1-1-1 Kouto, Sayo-cho, Hyogo, 679-5148 (Japan); Sato, I. [Oarai Research and Development Center, Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Ibaraki, 311-1393 (Japan); Kobayashi, K. [Quantum Beam Science Center, Japan Atomic Energy Agency, 1-1-1 Kouto, Sayo-cho, Hyogo, 679-5148 (Japan); Osaka, M. [Nuclear Science and Engineering Center, Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Ibaraki, 311-1393 (Japan); Yamagami, H. [Quantum Beam Science Center, Japan Atomic Energy Agency, 1-1-1 Kouto, Sayo-cho, Hyogo, 679-5148 (Japan); Faculty of Science, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto, 603-8555 (Japan)

2016-02-15

Highlights: • We have clarified the temperature-dependent chemical forms of Cs/I products. • We have examined the CsI-decomposing effects of B{sub 2}O{sub 3} vapor. • The possibility of Cs re-evaporation from CsI-deposited surface is suggested. • We have demonstrated the usefulness of HAXPES on FP chemistry. - Abstract: Transport behavior of CsI in the heating test, which simulated a BWR severe accident, was investigated by hard X-ray photoelectron spectroscopy (HAXPES) with an emphasis on the chemical effect of boron vapors. CsI deposited on metal tube at temperatures ranging from 150 °C to 750 °C was reacted with vapor/aerosol B{sub 2}O{sub 3}, and the chemical form of reaction products on the sample surface was examined from the HAXPES spectra of core levels, e.g., Ni 2p, Cs 3d and I 3d levels, and valence band. For the samples at ∼300 °C, while the chemical form of major product on the sample surface without an exposure to B{sub 2}O{sub 3} was suggested to be CsI from the HAXPES spectra, an intensity ratio of Cs/I was dramatically reduced at the sample surface after the reaction with B{sub 2}O{sub 3}. The results suggest the possibility of significant decomposition of deposited CsI induced by the chemical reaction with B{sub 2}O{sub 3} at specific temperatures.

Effect of coating systems on the vaporization of pentachlorophenol from treated wood

Science.gov (United States)

L. L. Ingram; G. D. McGinnis; P. M. Pope; W. C. Feist

1983-01-01

Specimens of southern pine treated with pentachlorophenol (penta) in mineral spirits (dip treatment), penta in P9 type A oil and penta in methylene chloride (pressure treatments) were used to evaluate the efficacy of different types of coatings in suppressing the vaporization of penta from treated wood. The clear film-forming coatings, such as polyurethane and alkyds,...

R\\&D results on a CsI-coated triple thick GEM-based photodetector

CERN Document Server

Martinengo, P; Paic, G; Paras, D M; Di Mauro, A; van Hoorne, J; Molnar, L; Peskov, V; Breskin, A

2011-01-01

The very high momentum particle identification detector proposed for the ALICE upgrade is a focusing RICH using a C(4)F(10) gaseous radiator. For the detection of Cherenkov photons, one of the options currently under investigation is to use a CsI-coated triple thick GEM with metallic or resistive electrodes. We will present results from the laboratory studies as well as preliminary results of beam tests of a RICH detector prototype consisting of a CaF(2) radiator coupled to a 10 x 10 cm(2) CsI-coated triple thick GEM equipped with a pad readout and GASSIPLEX-based front-end electronics. With such a prototype the detection of Cherenkov photons simultaneously with minimum ionizing particles has been achieved for the first time in a stable operation mode. (C) 2010 Elsevier B.V. All rights reserved.

High Temperature Multilayer Environmental Barrier Coatings Deposited Via Plasma Spray-Physical Vapor Deposition

Science.gov (United States)

Harder, Bryan James; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

2014-01-01

Si-based ceramic matrix composites (CMCs) require environmental barrier coatings (EBCs) in combustion environments to avoid rapid material loss. Candidate EBC materials have use temperatures only marginally above current technology, but the addition of a columnar oxide topcoat can substantially increase the durability. Plasma Spray-Physical Vapor Deposition (PS-PVD) allows application of these multilayer EBCs in a single process. The PS-PVD technique is a unique method that combines conventional thermal spray and vapor phase methods, allowing for tailoring of thin, dense layers or columnar microstructures by varying deposition conditions. Multilayer coatings were deposited on CMC specimens and assessed for durability under high heat flux and load. Coated samples with surface temperatures ranging from 2400-2700F and 10 ksi loads using the high heat flux laser rigs at NASA Glenn. Coating morphology was characterized in the as-sprayed condition and after thermomechanical loading using electron microscopy and the phase structure was tracked using X-ray diffraction.

The development of chemically vapor deposited mullite coatings for the corrosion protection of SiC

Energy Technology Data Exchange (ETDEWEB)

Auger, M.; Hou, P.; Sengupta, A.; Basu, S.; Sarin, V. [Boston Univ., MA (United States)

1998-05-01

Crystalline mullite coatings have been chemically vapor deposited onto SiC substrates to enhance the corrosion and oxidation resistance of the substrate. Current research has been divided into three distinct areas: (1) Development of the deposition processing conditions for increased control over coating`s growth rate, microstructure, and morphology; (2) Analysis of the coating`s crystal structure and stability; (3) The corrosion resistance of the CVD mullite coating on SiC.

Polymer-coated vertical-cavity surface-emitting laser diode vapor sensor

DEFF Research Database (Denmark)

Ansbæk, Thor; Nielsen, Claus Højgaard; Larsen, Niels Bent

2010-01-01

We report a new method for monitoring vapor concentration of volatile organic compounds using a vertical-cavity surface-emitting laser (VCSEL). The VCSEL is coated with a polymer thin film on the top distributed Bragg reflector (DBR). The analyte absorption is transduced to the electrical domain ...

Toward a High-Stability Coherent Population Trapping Cs Vapor-Cell Atomic Clock Using Autobalanced Ramsey Spectroscopy

Science.gov (United States)

Abdel Hafiz, Moustafa; Coget, Grégoire; Petersen, Michael; Rocher, Cyrus; Guérandel, Stéphane; Zanon-Willette, Thomas; de Clercq, Emeric; Boudot, Rodolphe

2018-06-01

Vapor-cell atomic clocks are widely appreciated for their excellent short-term fractional frequency stability and their compactness. However, they are known to suffer on medium and long time scales from significant frequency instabilities, generally attributed to light-induced frequency-shift effects. In order to tackle this limitation, we investigate the application of the recently proposed autobalanced Ramsey (ABR) interrogation protocol onto a pulsed hot-vapor Cs vapor-cell clock based on coherent population trapping (CPT). We demonstrate that the ABR protocol, developed initially to probe the one-photon resonance of quantum optical clocks, can be successfully applied to a two-photon CPT resonance. The applied method, based on the alternation of two successive Ramsey-CPT sequences with unequal free-evolution times and the subsequent management of two interconnected phase and frequency servo loops, is found to allow a relevant reduction of the clock-frequency sensitivity to laser-power variations. This original ABR-CPT approach, combined with the implementation of advanced electronics laser-power stabilization systems, yields the demonstration of a CPT-based Cs vapor-cell clock with a short-term fractional frequency stability at the level of 3.1×10 -13τ-1 /2 , averaging down to the level of 6 ×10-15 at 2000-s integration time. These encouraging performances demonstrate that the use of the ABR interrogation protocol is a promising option towards the development of high-stability CPT-based frequency standards. Such clocks could be attractive candidates in numerous applications including next-generation satellite-based navigation systems, secure communications, instrumentation, or defense systems.

Mechanical properties of chemical vapor deposited coatings for fusion reactor application

International Nuclear Information System (INIS)

Mullendore, A.W.; Whitley, J.B.; Pierson, H.O.; Mattox, D.M.

1980-01-01

Chemical vapor deposited coatings of TiB 2 , TiC and boron on graphite substrates are being developed for application as limiter materials in magnetic confinement fusion reactors. In this application severe thermal shock conditions exist and to do effective thermo-mechanical modelling of the material response it is necessary to acquire elastic moduli, fracture strength and strain to fracture data for the coatings. Four point flexure tests have been conducted from room temperature to 2000 0 C on TiB 2 and boron coated graphite with coatings in tension and compression and the mechanical properties extracted from the load-deflection data. In addition, stress relaxation tests from 500 to 1150 0 C were performed on TiB 2 and TiC coated graphite beams to assess the low levels of plastic deformation which occur in these coatings. Significant differences have been observed between the effective mechanical properties of the coatings and literature values of the bulk properties

Long-Term Stability of Polymer-Coated Surface Transverse Wave Sensors for the Detection of Organic Solvent Vapors.

Science.gov (United States)

Stahl, Ullrich; Voigt, Achim; Dirschka, Marian; Barié, Nicole; Richter, Christiane; Waldbaur, Ansgar; Gruhl, Friederike J; Rapp, Bastian E; Rapp, Michael; Länge, Kerstin

2017-11-03

Arrays with polymer-coated acoustic sensors, such as surface acoustic wave (SAW) and surface transverse wave (STW) sensors, have successfully been applied for a variety of gas sensing applications. However, the stability of the sensors' polymer coatings over a longer period of use has hardly been investigated. We used an array of eight STW resonator sensors coated with different polymers. This sensor array was used at semi-annual intervals for a three-year period to detect organic solvent vapors of three different chemical classes: a halogenated hydrocarbon (chloroform), an aliphatic hydrocarbon (octane), and an aromatic hydrocarbon (xylene). The sensor signals were evaluated with regard to absolute signal shifts and normalized signal shifts leading to signal patterns characteristic of the respective solvent vapors. No significant time-related changes of sensor signals or signal patterns were observed, i.e., the polymer coatings kept their performance during the course of the study. Therefore, the polymer-coated STW sensors proved to be robust devices which can be used for detecting organic solvent vapors both qualitatively and quantitatively for several years.

Microstructural Effects and Properties of Non-line-of-Sight Coating Processing via Plasma Spray-Physical Vapor Deposition

Science.gov (United States)

Harder, Bryan J.; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

2017-08-01

Plasma spray-physical vapor deposition (PS-PVD) is a unique processing method that bridges the gap between conventional thermal spray and vapor phase methods, and enables highly tailorable coatings composed of a variety of materials in thin, dense layers or columnar microstructures with modification of the processing conditions. The strengths of this processing technique are material and microstructural flexibility, deposition speed, and potential for non-line-of-sight (NLOS) capability by vaporization of the feedstock material. The NLOS capability of PS-PVD is investigated here using yttria-stabilized zirconia and gadolinium zirconate, which are materials of interest for turbine engine applications. PS-PVD coatings were applied to static cylindrical substrates approximately 6-19 mm in diameter to study the coating morphology as a function of angle. In addition, coatings were deposited on flat substrates under various impingement configurations. Impingement angle had significant effects on the deposition mode, and microscopy of coatings indicated that there was a shift in the deposition mode at approximately 90° from incidence on the cylindrical samples, which may indicate the onset of more turbulent flow and PVD-like growth. Coatings deposited at non-perpendicular angles exhibited a higher density and nearly a 2× improvement in erosion performance when compared to coatings deposited with the torch normal to the surface.

Synthesis of mullite coatings by chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Mulpuri, R.P.; Auger, M.; Sarin, V.K. [Boston Univ., MA (United States)

1996-08-01

Formation of mullite on ceramic substrates via chemical vapor deposition was investigated. Mullite is a solid solution of Al{sub 2}O{sub 3} and SiO{sub 2} with a composition of 3Al{sub 2}O{sub 3}{circ}2SiO{sub 2}. Thermodynamic calculations performed on the AlCl{sub 3}-SiCl{sub 4}-CO{sub 2}-H{sub 2} system were used to construct equilibrium CVD phase diagrams. With the aid of these diagrams and consideration of kinetic rate limiting factors, initial process parameters were determined. Through process optimization, crystalline CVD mullite coatings have been successfully grown on SiC and Si{sub 3}N{sub 4} substrates. Results from the thermodynamic analysis, process optimization, and effect of various process parameters on deposition rate and coating morphology are discussed.

Tuning of the Hanle effect from EIT to EIA using spatially separated probe and control beams.

Science.gov (United States)

Bhattarai, Mangesh; Bharti, Vineet; Natarajan, Vasant

2018-05-14

We demonstrate a technique for continuous tuning of the Hanle effect from electromagnetically induced transparency (EIT) to electromagnetically induced absorption (EIA) by changing the polarization ellipticity of a control beam. In contrast to previous work in this field, we use spatially separated probe and control beams. The experiments are done using magnetic sublevels of the F g  = 4 → F e  = 5 closed hyperfine transition in the 852 nm D 2 line of 133 Cs. The atoms are contained in a room temperature vapor cell with anti-relaxation (paraffin) coating on the walls. The paraffin coating is necessary for the atomic coherence to be transported between the beams. The experimental results are supported by a density-matrix analysis of the system, which also explains the observed amplitude and zero-crossing of the resonances. Such continuous tuning of the sign of a resonance has important applications in quantum memory and other precision measurements.

Surface and Bulk Characteristics of Cesium Iodide (CsI) coated Carbon (C) Fibers for High Power Microwave (HPM) Field Emission Cathodes

Science.gov (United States)

Vlahos, Vasilios; Morgan, Dane; Booske, John H.; Shiffler, Don

2008-11-01

CsI coated C fibers [1] are promising field emission cathodes for HPM applications. Ab initio computational modeling has shown that atomically-thin CsI coatings reduce the work function of C substrates by a surface dipole mechanism [2]. Characterization measurements of the composition and morphology of the CsI-coated C fibers are underway for determining the properties and characteristics of the following important regions of the fiber: (i) the surface on the tip of the fiber where the majority of electron emission is believed to occur, (ii) the surface covering the body of the fiber and its role on the emission properties of the system, and (iii) the interior volume of the fiber and its effects on the CsI surface re-supply process and rate. The results will be interpreted in terms of surface electronic properties and theoretical electron emission models. [1]D. Shiffler, et al., Phys. Plasmas 11 (2004) 1680. [2]V.Vlahos et al., Appl. Phys. Lett. 91 (2007) 144102.

Radiative transport and collisional transfer of excitation energy in Cs vapors mixed with Ar or He

International Nuclear Information System (INIS)

Vadla, Cedomil; Horvatic, Vlasta; Niemax, Kay

2003-01-01

This paper is a review (with a few original additions) on the radiative transport and collisional transfer of energy in laser-excited cesium vapors in the presence of argon or helium. Narrow-band excitation of lines with Lorentz, Doppler and Voigt profiles is studied in order to calculate effective rates for pumping of spectral lines with profiles comprising inhomogeneous broadening components. The radiative transport of excitation energy is considered, and a new, simple and robust, but accurate theoretical method for quantitative treatment of radiation trapping in relatively optically thin media is presented. Furthermore, comprehensive lists of experimental values for the excitation energy transfer cross-sections related to thermal collisions in Cs-Ar and Cs-He mixtures are given. Within the collected cross-section data sets, specific regularities with respect to the energy defect, as well as the temperature, are discerned. A particular emphasis is put on the radiative and collisional processes important for the optimization of resonance-fluorescence imaging atomic filters based on Cs-noble gas systems

SiO2 coating of silver nanoparticles by photoinduced chemical vapor deposition

International Nuclear Information System (INIS)

Boies, Adam M; Girshick, Steven L; Roberts, Jeffrey T; Zhang Bin; Nakamura, Toshitaka; Mochizuki, Amane

2009-01-01

Gas-phase silver nanoparticles were coated with silicon dioxide (SiO 2 ) by photoinduced chemical vapor deposition (photo-CVD). Silver nanoparticles, produced by inert gas condensation, and a SiO 2 precursor, tetraethylorthosilicate (TEOS), were exposed to vacuum ultraviolet (VUV) radiation at atmospheric pressure and varying temperatures. The VUV photons dissociate the TEOS precursor, initiating a chemical reaction that forms SiO 2 coatings on the particle surfaces. Coating thicknesses were measured for a variety of operation parameters using tandem differential mobility analysis and transmission electron microscopy. The chemical composition of the particle coatings was analyzed using energy dispersive x-ray spectrometry and Fourier transform infrared spectroscopy. The highest purity films were produced at 300-400 0 C with low flow rates of additional oxygen. The photo-CVD coating technique was shown to effectively coat nanoparticles and limit core particle agglomeration at concentrations up to 10 7 particles cm -3 .

Chemical vapor deposition of aluminide coatings on iron, nickel and superalloys

International Nuclear Information System (INIS)

John, John T.; De, P.K.; Dubey, Vivekanand; Srinivasa, Raman

2009-08-01

Aluminide coatings are a class of intermetallic coatings applied on nickel and cobalt base superalloys and steels to protect them from different forms of environmental degradation at high temperatures. In this report a CVD system that can produce the aluminide coatings on iron, nickel and nickel base alloys has been described and the result of chemical vapor deposition of aluminide coatings on iron specimens, their characterization, and property evaluation have been presented. The CVD system consists of an AlCl 3 bath, a stainless steel retort as a hot-wall reacto, cold traps and vacuum system. Aluminium chloride vapor was carried in a stream of hydrogen gas at a flow rate of 150 SCCM (standard cubic centimeter per minute) into the CVD reactor maintained in the temperature range of 1173 - 1373 K and at a pressure of 1.33 kPa (10 Torr). Aluminum deposition takes place from aluminium subchlorides produced by reaction between AlCl 3 and pure aluminum kept in the CVD reactor. The aluminum diffuses into the iron samples and iron aluminide phases are formed at the surface. The coatings were shining bright and showed good adherence to the substrate. The coatings consisted of FeAl phase over a wide range of experimental conditions. The growth kinetics of the coating followed a parabolic rate law and the mean activation energy was 212 ±16 kJ/mol. Optical microscopic studies on the transverse section of the coating showed that the aluminide coating on iron consisted of two layers. The top layer had a thickness in the range of 20-50 μm, and the under layer had thickness ranging from 35 to 250 μm depending on coating temperature in two hours. The thickness of the aluminide layer increased with coating duration and temperature. Electron microprobe studies (EPMA) showed that the aluminum concentration decreased steadily as distance from the surface increased. TEM studies showed that the outer most layer had a B2 order (of the FeAl phase), which extended even into the under

Research on chemical vapor deposition processes for advanced ceramic coatings

Science.gov (United States)

Rosner, Daniel E.

1993-01-01

Our interdisciplinary background and fundamentally-oriented studies of the laws governing multi-component chemical vapor deposition (VD), particle deposition (PD), and their interactions, put the Yale University HTCRE Laboratory in a unique position to significantly advance the 'state-of-the-art' of chemical vapor deposition (CVD) R&D. With NASA-Lewis RC financial support, we initiated a program in March of 1988 that has led to the advances described in this report (Section 2) in predicting chemical vapor transport in high temperature systems relevant to the fabrication of refractory ceramic coatings for turbine engine components. This Final Report covers our principal results and activities for the total NASA grant of $190,000. over the 4.67 year period: 1 March 1988-1 November 1992. Since our methods and the technical details are contained in the publications listed (9 Abstracts are given as Appendices) our emphasis here is on broad conclusions/implications and administrative data, including personnel, talks, interactions with industry, and some known applications of our work.

The detection of organic solvent vapor by using polymer coated chemocapacitor sensor

Science.gov (United States)

Rusdiarna Indrapraja, Apik; Rivai, Muhammad; Arifin, Achmad; Purwanto, Djoko

2017-05-01

A chemocapacitor consists of planar interdigital electrodes (IDE) made by two comb electrodes on a substrate. A dielectric film was applied on the electrodes in which the absorbed vapor will modify its permittivity. This study has fabricated chemocapacitor with the IDE distance of 0.5 mm, while the dielectric film was a sensitive layer consisting of a polymeric material. The deposition of the polymeric film was accomplished by drop casting. A sensor array consisting of four chemocapacitors coated with different polymers namely PEG-1540, PEG-20M, PEG-6000, and PVP was used to obtain the pattern of shift in the capacitance. The integrated circuit AD7746 was used as the capacitance to-digital converter (CDC). The organic solvents of ethanol, benzene, and aceton were used as the vapor samples in this experiment. The results showed that the change in the capacitance value increases proportionally to the concentration of vapour where sensors coated with PEG-1540 and PVP have higher sensitivity, i.e. 0.0028pF/part per thousand and 0.0027pF/part per thousand, respectively. Based on the capacitance to digital conversion capabilities, the system provides there solution of 0.4084ppm. The sensor array could produce a different pattern for each of the vapor sample. The Neural Network pattern recognition system could identify the type of vapor automatically with the root mean square error of 10-5

Novel Prospects for Plasma Spray-Physical Vapor Deposition of Columnar Thermal Barrier Coatings

Science.gov (United States)

Anwaar, Aleem; Wei, Lianglinag; Guo, Qian; Zhang, Baopeng; Guo, Hongbo

2017-12-01

Plasma spray-physical vapor deposition (PS-PVD) is an emerging coating technique that can produce columnar thermal barrier coatings from vapor phase. Feedstock treatment at the start of its trajectory in the plasma torch nozzle is important for such vapor-phase deposition. This study describes the effects of the plasma composition (Ar/He) on the plasma characteristics, plasma-particle interaction, and particle dynamics at different points spatially distributed inside the plasma torch nozzle. The results of calculations show that increasing the fraction of argon in the plasma gas mixture enhances the momentum and heat flow between the plasma and injected feedstock. For the plasma gas combination of 45Ar/45He, the total enthalpy transferred to a representative powder particle inside the plasma torch nozzle is highest ( 9828 kJ/kg). Moreover, due to the properties of the plasma, the contribution of the cylindrical throat, i.e., from the feed injection point (FIP) to the start of divergence (SOD), to the total transferred energy is 69%. The carrier gas flow for different plasma gas mixtures was also investigated by optical emission spectroscopy (OES) measurements of zirconium emissions. Yttria-stabilized zirconia (YSZ) coating microstructures were produced when using selected plasma gas compositions and corresponding carrier gas flows; structural morphologies were found to be in good agreement with OES and theoretical predictions. Quasicolumnar microstructure was obtained with porosity of 15% when applying the plasma composition of 45Ar/45He.

Corrosion processes of physical vapor deposition-coated metallic implants.

Science.gov (United States)

Antunes, Renato Altobelli; de Oliveira, Mara Cristina Lopes

2009-01-01

Protecting metallic implants from the harsh environment of physiological fluids is essential to guaranteeing successful long-term use in a patient's body. Chemical degradation may lead to the failure of an implant device in two different ways. First, metal ions may cause inflammatory reactions in the tissues surrounding the implant and, in extreme cases, these reactions may inflict acute pain on the patient and lead to loosening of the device. Therefore, increasing wear strength is beneficial to the performance of the metallic implant. Second, localized corrosion processes contribute to the nucleation of fatigue cracks, and corrosion fatigue is the main reason for the mechanical failure of metallic implants. Common biomedical alloys such as stainless steel, cobalt-chrome alloys, and titanium alloys are prone to at least one of these problems. Vapor-deposited hard coatings act directly to improve corrosion, wear, and fatigue resistances of metallic materials. The effectiveness of the corrosion protection is strongly related to the structure of the physical vapor deposition layer. The aim of this paper is to present a comprehensive review of the correlation between the structure of physical vapor deposition layers and the corrosion properties of metallic implants.

Ion vapor deposition and its application

International Nuclear Information System (INIS)

Bollinger, H.; Schulze, D.; Wilberg, R.

1981-01-01

Proceeding from the fundamentals of ion vapor deposition the characteristic properties of ion-plated coatings are briefly discussed. Examples are presented of successful applications of ion-plated coatings such as coatings with special electrical and dielectric properties, coatings for corrosion prevention, and coatings for improving the surface properties. It is concluded that ion vapor deposition is an advantageous procedure in addition to vapor deposition. (author)

Coating of carbon short fibers with thin ceramic layers by chemical vapor deposition

International Nuclear Information System (INIS)

Hackl, Gerrit; Gerhard, Helmut; Popovska, Nadejda

2006-01-01

Carbon short fiber bundles with a length of 6 mm were uniformly coated using specially designed, continuous chemical vapor deposition (CVD) equipment. Thin layers of titanium nitride, silicon nitride (SiC) and pyrolytic carbon (pyC) were deposited onto several kilograms of short fibers in this large scale CVD reactor. Thermo-gravimetric analyses and scanning electron microscopy investigations revealed layer thicknesses between 20 and 100 nm on the fibers. Raman spectra of pyC coated fibers show a change of structural order depending on the CVD process parameters. For the fibers coated with SiC, Raman investigations showed a deposition of amorphous SiC. The coated carbon short fibers will be applied as reinforcing material in composites with ceramic and metallic matrices

Investigation of pump-to-seed beam matching on output features of Rb and Cs vapor laser amplifiers

Science.gov (United States)

Shen, Binglin; Huang, Jinghua; Xu, Xingqi; Xia, Chunsheng; Pan, Bailiang

2018-05-01

Taking into account the beam radii of pump light and seed laser along the entire length of the cell and their intensities in the cross section, a physical model with ordinary differential equation methods for alkali vapor amplifiers is established. Applied to the reported optically pumped Rb and diode-pumped Cs vapor amplifiers, the model shows good agreement between the calculated and measured dependence of amplified power on the seed power. A larger width of the spontaneous emission region as compared to the widths of pump absorption and laser emission regions, which will result in very high energy losses, is observed in the cell. Influence of pump and seed beam waists on output performance is calculated, showing that the pump and seed beam should match each other not only in shape but also in size, thus an optimal combination of beam radii is very important for efficient operation of alkali vapor amplifiers.

SiO{sub 2} coating of silver nanoparticles by photoinduced chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Boies, Adam M; Girshick, Steven L [Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN 55455 (United States); Roberts, Jeffrey T [Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455 (United States); Zhang Bin; Nakamura, Toshitaka; Mochizuki, Amane, E-mail: jtrob@umn.ed, E-mail: slg@umn.ed [Nitto Denko Technical Corporation, 501 Via Del Monte, Oceanside, CA 92058 (United States)

2009-07-22

Gas-phase silver nanoparticles were coated with silicon dioxide (SiO{sub 2}) by photoinduced chemical vapor deposition (photo-CVD). Silver nanoparticles, produced by inert gas condensation, and a SiO{sub 2} precursor, tetraethylorthosilicate (TEOS), were exposed to vacuum ultraviolet (VUV) radiation at atmospheric pressure and varying temperatures. The VUV photons dissociate the TEOS precursor, initiating a chemical reaction that forms SiO{sub 2} coatings on the particle surfaces. Coating thicknesses were measured for a variety of operation parameters using tandem differential mobility analysis and transmission electron microscopy. The chemical composition of the particle coatings was analyzed using energy dispersive x-ray spectrometry and Fourier transform infrared spectroscopy. The highest purity films were produced at 300-400 {sup 0}C with low flow rates of additional oxygen. The photo-CVD coating technique was shown to effectively coat nanoparticles and limit core particle agglomeration at concentrations up to 10{sup 7} particles cm{sup -3}.

Investigation on the corrosion behavior of physical vapor deposition coated high speed steel

Directory of Open Access Journals (Sweden)

R Ravi Raja Malarvannan

2015-08-01

Full Text Available This work emphasizes on the influence of the TiN and AlCrN coatings fabricated on high speed steel form tool using physical vapor deposition technique. The surface microstructure of the coatings was studied using scanning electron microscope. Hardness and corrosion studies were also performed using Vickers hardness test and salt spray testing, respectively. The salt spray test results suggested that the bilayer coated (TiN- bottom layer and AlCrN- top layer substrate has undergone less amount of corrosion, and this is attributed to the dense microstructure. In addition to the above, the influence of the above coatings on the machining performance of the high speed steel was also evaluated and compared with that of the uncoated material and the results suggested that the bilayered coating has undergone very low weight loss when compared with that of the uncoated substrate depicting enhanced wear resistance.

A rapid method of reprocessing for electronic microscopy of cut histological in paraffin

International Nuclear Information System (INIS)

Hernandez Chavarri, F.; Vargas Montero, M.; Rivera, P.; Carranza, A.

2000-01-01

A simple and rapid method is described for re-processing of light microscopy paraffin sections to observe they under transmission electron microscopy (TEM) and scanning electron microscopy (SEM) The paraffin-embedded tissue is sectioned and deparaffinized in toluene; then exposed to osmium vapor under microwave irradiation using a domestic microwave oven. The tissues were embedded in epoxy resin, polymerized and ultrathin sectioned. The method requires a relatively short time (about 30 minutes for TEM and 15 for SEM), and produces a reasonable quality of the ultrastructure for diagnostic purposes. (Author) [es

Enhanced thermal properties with graphene oxide in the urea-formaldehyde microcapsules containing paraffin PCMs.

Science.gov (United States)

Qiao, Zhen; Mao, Jian

2017-02-01

In this study, compact urea-formaldehyde microcapsules containing paraffin (UFP) phase change materials (PCMs) were prepared via in situ polymerisation. The thermal conductivity of the PCMs was enhanced without influencing their enthalpy by adding graphene oxide (GO). Two modification methods were investigated: One in which GO is added to the inside of microcapsules, defined as "paraffin/GO@UF composite"; and another in which GO is coated onto the surface of shell, defined as "paraffin@UF/GO composite". The GO sheets were visible in scanning electron microscope (SEM) images of paraffin@UF/GO composite. The thermal conductivity was 0.2236 ± 0.0003 W/(m·K) for UFP particles, was 0.2517 ± 0.0003 W/(m·K) for the paraffin/GO@UF composite (10 wt%), and was 1.0670 ± 0.0020 W/(m·K) for paraffin@UF/GO composite (10 wt%), respectively. The encapsulation efficiency of all samples exceeded 80% (w/w) and all samples exhibited favourable thermal stability and reliability. The IR emissivity of paraffin@UF/GO was lower than that of paraffin/GO@UF when the same GO amount was added to the composite.

Dual-Phase CsPbBr3 -CsPb2 Br5 Perovskite Thin Films via Vapor Deposition for High-Performance Rigid and Flexible Photodetectors.

Science.gov (United States)

Tong, Guoqing; Li, Huan; Li, Danting; Zhu, Zhifeng; Xu, Enze; Li, Guopeng; Yu, Linwei; Xu, Jun; Jiang, Yang

2018-02-01

Inorganic perovskites with special semiconducting properties and structures have attracted great attention and are regarded as next generation candidates for optoelectronic devices. Herein, using a physical vapor deposition process with a controlled excess of PbBr 2 , dual-phase all-inorganic perovskite composite CsPbBr 3 -CsPb 2 Br 5 thin films are prepared as light-harvesting layers and incorporated in a photodetector (PD). The PD has a high responsivity and detectivity of 0.375 A W -1 and 10 11 Jones, respectively, and a fast response time (from 10% to 90% of the maximum photocurrent) of ≈280 µs/640 µs. The device also shows an excellent stability in air for more than 65 d without encapsulation. Tetragonal CsPb 2 Br 5 provides satisfactory passivation to reduce the recombination of the charge carriers, and with its lower free energy, it enhances the stability of the inorganic perovskite devices. Remarkably, the same inorganic perovskite photodetector is also highly flexible and exhibits an exceptional bending performance (>1000 cycles). These results highlight the great potential of dual-phase inorganic perovskite films in the development of optoelectronic devices, especially for flexible device applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid and sensitive determination of radiocesium (Cs-135, Cs-137) in the presence of excess barium by electrothermal vaporization-inductively coupled plasma-mass spectrometry (ETV-ICP-MS) with potassium thiocyanate as modifier

International Nuclear Information System (INIS)

Song, M.; Probst, T.U.; Berryman, N.G.

2001-01-01

An electrothermal vaporization-inductively coupled plasma-mass spectrometric (ETV-ICP-MS) method based on selective volatilization of cesium with KSCN as modifier has been developed for determination of radiocesium, i.e. 135 Cs and 137 Cs, in the presence of isobaric barium. A 10000 times excess of barium, which was volatilized at a temperature of 1100 C, resulted only in a 1% signal increase in the signal of mass 135 amu. The recommended concentration of KSCN is 0.3 mM, and pretreatment and volatilization temperatures are 400 C and 1100 C, respectively. A ramp time of 1 s is recommended for the volatilization step. The achieved limit of detection for 135 Cs is 0.2 pg/mL (10 μBq/mL) and 4 fg (0.2 μBq) absolute for a sample volume of 20 μL. This means a limit of detection for 137 Cs of 0.2 pg/mL (0.6 Bq/mL) and of 4 fg (0.01 Bq) absolute. Signal variations of 135 Cs and 137 Cs, respectively, in spiked samples with various matrices were investigated. (orig.)

Sensitive coating for water vapors detection based on thermally sputtered calcein thin films.

Science.gov (United States)

Kruglenko, I; Shirshov, Yu; Burlachenko, J; Savchenko, A; Kravchenko, S; Manera, M G; Rella, R

2010-09-15

In this paper the adsorption properties of thermally sputtered calcein thin films towards water and other polar molecules vapors are studied by different characterization techniques: quartz crystal microbalance, surface plasmon resonance and visible spectroscopy. Sensitivity of calcein thin films to water vapors resulted much higher as compared with those of a number of dyes whose structure was close to that of calcein. All types of sensors with calcein coatings have demonstrated linear concentration dependences in the wide range of water vapor pressure from low concentrations up to 27,000 ppm (close to saturation). At higher concentrations of water vapor all sensors demonstrate the abrupt increase of the response (up to two orders). A theoretical model is advanced explaining the adsorption properties of calcein thin films taking into account their chemical structure and peculiarities of molecular packing. The possibility of application of thermally sputtered calcein films in sensing technique is discussed. Copyright (c) 2010 Elsevier B.V. All rights reserved.

CMAS Interactions with Advanced Environmental Barrier Coatings Deposited via Plasma Spray- Physical Vapor Deposition

Science.gov (United States)

Harder, B. J.; Wiesner, V. L.; Zhu, D.; Johnson, N. S.

2017-01-01

Materials for advanced turbine engines are expected to have temperature capabilities in the range of 1370-1500C. At these temperatures the ingestion of sand and dust particulate can result in the formation of corrosive glass deposits referred to as CMAS. The presence of this glass can both thermomechanically and thermochemically significantly degrade protective coatings on metallic and ceramic components. Plasma Spray- Physical Vapor Deposition (PS-PVD) was used to deposit advanced environmental barrier coating (EBC) systems for investigation on their interaction with CMAS compositions. Coatings were exposed to CMAS and furnace tested in air from 1 to 50 hours at temperatures ranging from 1200-1500C. Coating composition and crystal structure were tracked with X-ray diffraction and microstructure with electron microscopy.

Microstructure analysis of zirconium carbide layer on pyrocarbon-coated particles prepared by zirconium chloride vapor method

International Nuclear Information System (INIS)

Zhao Hongsheng; Liu Bing; Zhang Kaihong; Tang Chunhe

2012-01-01

Zirconium carbide (ZrC) layer on pyrocarbon-coated particles was successfully prepared in a fluidized bed coater furnace by chemical vapor deposition using a zirconium chloride (ZrCl 4 ) vapor method and quantitative controlling of the Zr-source through a ZrCl 4 powder feeder. The crystal phase, microstructure and chemical composition of ZrC-coating layer were analyzed using X-ray diffraction (XRD), optical metallographical microscope, scanning electron microscope (SEM), transmission electron microscope (TEM), high-resolution transmission electron microscope (HR-TEM) and X-ray photoelectron spectroscopy (XPS). The results show that the deposited ZrC-coating layer has smooth and compact surface, no obvious holes, clear interface with dense pyrocarbon layer, and a thickness of 35 μm. The main phase of ZrC-coating layer is fcc-ZrC crystal, which is composed of small grains with the size of 20–50 nm. The grain size increases monotonously with the deposition temperature increasing. The main elements of ZrC-coating layer are Zr and C, and the Zr/C molar ratio is close to 1:1. The analysis of composition and crystal structure suggest that a stoichiometric fcc-ZrC crystal was obtained and no obvious preferred orientation of the grains was found.

Thermal barrier coatings on gas turbine blades: Chemical vapor deposition (Review)

Science.gov (United States)

Igumenov, I. K.; Aksenov, A. N.

2017-12-01

Schemes are presented for experimental setups (reactors) developed at leading scientific centers connected with the development of technologies for the deposition of coatings using the CVD method: at the Technical University of Braunschweig (Germany), the French Aerospace Research Center, the Materials Research Institute (Tohoku University, Japan) and the National Laboratory Oak Ridge (USA). Conditions and modes for obtaining the coatings with high operational parameters are considered. It is established that the formed thermal barrier coatings do not fundamentally differ in their properties (columnar microstructure, thermocyclic resistance, thermal conductivity coefficient) from standard electron-beam condensates, but the highest growth rates and the perfection of the crystal structure are achieved in the case of plasma-chemical processes and in reactors with additional laser or induction heating of a workpiece. It is shown that CVD reactors can serve as a basis for the development of rational and more advanced technologies for coating gas turbine blades that are not inferior to standard electron-beam plants in terms of the quality of produced coatings and have a much simpler and cheaper structure. The possibility of developing a new technology based on CVD processes for the formation of thermal barrier coatings with high operational parameters is discussed, including a set of requirements for industrial reactors, high-performance sources of vapor precursors, and promising new materials.

Ultra-Tuning of the Rare-Earth fcu-MOF Aperture Size for Selective Molecular Exclusion of Branched Paraffins

KAUST Repository

Assen, Ayalew Hussen Assen

2015-10-02

Using isoreticular chemistry allows the design and construction of a new rare-earth metal (RE) fcu-MOF with a suitable aperture size for practical steric adsorptive separations. The judicious choice of a relatively short organic building block, namely fumarate, to bridge the 12-connected RE hexanuclear clusters has afforded the contraction of the well-defined RE-fcu-MOF triangular window aperture, the sole access to the two interconnected octahedral and tetrahedral cages. The newly constructed RE (Y and Tb) fcu-MOF analogues display unprecedented total exclusion of branched paraffins from normal paraffins. The resultant window aperture size of about 4.7 Å, regarded as a sorbate-size cut-off, enabled a complete sieving of branched paraffins from normal paraffins. The results are supported by collective single gas and mixed gas/vapor adsorption and calorimetric studies.

Fabrication and characterization of Ni-YSZ anode functional coatings by electron beam physical vapor deposition

International Nuclear Information System (INIS)

Meng, B.; Sun, Y.; He, X.D.; Peng, J.H.

2009-01-01

Two kinds of NiO-YSZ (yttria-stabilized zirconia) coatings, respectively with uniform and gradient distributions of NiO content along the coating thickness direction, were prepared by electron beam physical vapor deposition (EB-PVD) via adjusting electron beam currents. Then uniform and graded Ni-YSZ coatings were obtained from corresponding NiO-YSZ coatings after a reduction treatment. For uniform Ni-YSZ coating, the composition and porosity distributions along the coating thickness were uniform. The specific surface area and total pore volume for this coating could reach up to 4.330 m 2 g -1 and 0.0346 cm 3 g -1 respectively. The area specific resistance (ASR) of this coating kept increasing with the rise in temperature and an ASR of 2.1 x 10 -5 Ω cm 2 was obtained at 600 o C. For graded Ni-YSZ coating, a gradient in Ni content and porosity was realized along the coating thickness. A high porosity of up to 33% was achieved in the part of the coating close to the substrate, while a low porosity of 10% was obtained in the part close to coating surface.

An integrated optic ethanol vapor sensor based on a silicon-on-insulator microring resonator coated with a porous ZnO film.

Science.gov (United States)

Yebo, Nebiyu A; Lommens, Petra; Hens, Zeger; Baets, Roel

2010-05-24

Optical structures fabricated on silicon-on-insulator technology provide a convenient platform for the implementation of highly compact, versatile and low cost devices. In this work, we demonstrate the promise of this technology for integrated low power and low cost optical gas sensing. A room temperature ethanol vapor sensor is demonstrated using a ZnO nanoparticle film as a coating on an SOI micro-ring resonator of 5 microm in radius. The local coating on the ring resonators is prepared from colloidal suspensions of ZnO nanoparticles of around 3 nm diameter. The porous nature of the coating provides a large surface area for gas adsorption. The ZnO refractive index change upon vapor adsorption shifts the microring resonance through evanescent field interaction. Ethanol vapor concentrations down to 100 ppm are detected with this sensing configuration and a detection limit below 25 ppm is estimated.

Preventing Paraffin-Related Injury

Directory of Open Access Journals (Sweden)

Dehran Swart

2009-07-01

Full Text Available Paraffin (called kerosene in North America and other parts of the world is the most commonly used fuel in ‎non-electrified dwellings worldwide. It is especially popular in Africa and South Asia. Although paraffin ‎offers many advantages – especially its comparatively low cost to produce – it poses two major risks of ‎injury. First, paraffin poisoning is common, either through ingestion or through inhalation of smoke and ‎fumes. Second, paraffin is highly flammable, and poses fire risk through multiple causes. This commentary ‎discusses strategies to prevent paraffin-related injury. Prevention of paraffin-related injury must be through ‎multiple strategies, and should include policy-oriented change, changes to the safety of home environments, ‎and behavioral changes targeting how individuals store and use paraffin and paraffin appliances. We review ‎successful prevention strategies in each of these domains and discuss appropriate research and community ‎initiatives that should be implemented to improve paraffin safety among at-risk populations.‎

Enhanced cyclic stability of SnS microplates with conformal carbon coating derived from ethanol vapor deposition for sodium-ion batteries

Science.gov (United States)

Li, Xiang; Liu, Jiangwen; Ouyang, Liuzhang; Yuan, Bin; Yang, Lichun; Zhu, Min

2018-04-01

Carbon coated SnS microplates (SnS@C MPs) were prepared via a facile chemical vapor deposition method using SnS2 nanoflakes as precursor and ethanol vapor as carbon source. The carbon coating restrains the growth of SnS during the heat treatment. Furthermore, it improves the electronic conductivity as well as accommodates volume variations of SnS during the sodiation and desodiation processes. Therefore, the rate capability and cycle performance of the SnS@C MPs as anode materials for sodium-ion batteries are remarkably enhanced compared with the bare SnS and the SnS2 precursor. At current densities of 0.1, 0.2, 0.5, 1 and 2 A g-1, the optimized SnS@C MPs exhibit stable capacities of 602.9, 532.1, 512.2, 465.9 and 427.2 mAh g-1, respectively. At 1 A g-1, they show a reversible capacity of 528.8 mAh g-1 in the first cycle, and maintain 444.7 mAh g-1 after 50 cycles, with capacity retention of 84.1%. The carbon coating through chemical vapor deposition using ethanol vapor as carbon sources is green, simple and cost-effective, which shows great promise to improve the reversible Na+ storage of electrode materials.

Vapor pressure and thermodynamics of beryllium carbide

International Nuclear Information System (INIS)

Rinehart, G.H.; Behrens, R.G.

1980-01-01

The vapor pressure of beryllium carbide has been measured over the temperature range 1388 to 1763 K using Knudsen-effusion mass spectrometry. Vaporization occurs incongruently according to the reaction Be 2 C(s) = 2Be(g) + C(s). The equilibrium vapor pressure above the mixture of Be 2 C and C over the experimental temperature range is (R/J K -1 mol -1 )ln(p/Pa) = -(3.610 +- 0.009) x 10 5 (K/T) + (221.43 +- 1.06). The third-law enthalpy change for the above reaction obtained from the present vapor pressures is ΔH 0 (298.15 K) = (740.5 +- 0.1) kJ mol -1 . The corresponding second-law result is ΔH 0 (298.15 K) = (732.0 +- 1.8) kJ mol -1 . The enthalpy of formation for Be 2 C(s) calculated from the present third-law vaporization enthalpy and the enthalpy of formation of Be(g) is ΔH 0 sub(f)(298.15 K) = -(92.5 +- 15.7) kJ mol -1 . (author)

Biocompatibility of Titania Nanotube Coatings Enriched with Silver Nanograins by Chemical Vapor Deposition

Directory of Open Access Journals (Sweden)

Piotr Piszczek

2017-09-01

Full Text Available Bioactivity investigations of titania nanotube (TNT coatings enriched with silver nanograins (TNT/Ag have been carried out. TNT/Ag nanocomposite materials were produced by combining the electrochemical anodization and chemical vapor deposition methods. Fabricated coatings were characterized by scanning electron microscopy (SEM, X-ray photoelectron spectroscopy (XPS, and Raman spectroscopy. The release effect of silver ions from TNT/Ag composites immersed in bodily fluids, has been studied using inductively coupled plasma mass spectrometry (ICP-MS. The metabolic activity assay (MTT was applied to determine the L929 murine fibroblasts adhesion and proliferation on the surface of TNT/Ag coatings. Moreover, the results of immunoassays (using peripheral blood mononuclear cells—PBMCs isolated from rats allowed the estimation of the immunological activity of TNT/Ag surface materials. Antibacterial activity of TNT/Ag coatings with different morphological and structural features was estimated against two Staphylococcus aureus strains (ATCC 29213 and H9. The TNT/Ag nanocomposite layers produced revealed a good biocompatibility promoting the fibroblast adhesion and proliferation. A desirable anti-biofilm activity against the S. aureus reference strain was mainly noticed for these TiO2 nanotube coatings, which contain dispersed Ag nanograins deposited on their surface.

Effects of argon and oxygen flow rate on water vapor barrier properties of silicon oxide coatings deposited on polyethylene terephthalate by plasma enhanced chemical vapor deposition

International Nuclear Information System (INIS)

Kim, Sung-Ryong; Choudhury, Moinul Haque; Kim, Won-Ho; Kim, Gon-Ho

2010-01-01

Plasma polymer coatings were deposited from hexamethyldisiloxane on polyethylene terephthalate (PET) substrates while varying the operating conditions, such as the Ar and O 2 flow rates, at a fixed radio frequency power of 300 W. The water vapor transmission rate (WVTR) of the untreated PET was 54.56 g/m 2 /day and was decreased after depositing the silicon oxide (SiO x ) coatings. The minimum WVTR, 0.47 g/m 2 /day, was observed at Ar and O 2 flow rates of 4 and 20 sccm, respectively, with a coating thickness of 415.44 nm. The intensity of the peaks for the Si-O-Si bending at 800-820 cm -1 and Si-O-Si stretching at 1000-1150 cm -1 varied depending on the Ar and O 2 flow rates. The contact angle of the SiO x coated PET increased as the Ar flow rate was increased from 2 to 8 sccm at a fixed O 2 flow rate of 20 sccm. It decreased gradually as the oxygen flow rate increased from 12 to 28 sccm at a fixed Ar carrier gas flow rate. The examination by atomic force microscopy revealed a correlation of the SiO x morphology and the water vapor barrier performance with the Ar and O 2 flow rates. The roughness of the deposited coatings increased when either the O 2 or Ar flow rate was increased.

Nanoparticle-coated micro-optofluidic ring resonator as a detector for microscale gas chromatographic vapor analysis.

Science.gov (United States)

Scholten, K; Collin, W R; Fan, X; Zellers, E T

2015-05-28

A vapor sensor comprising a nanoparticle-coated microfabricated optofluidic ring resonator (μOFRR) is introduced. A multilayer film of polyether functionalized, thiolate-monolayer-protected gold nanoparticles (MPN) was solvent cast on the inner wall of the hollow cylindrical SiOxμOFRR resonator structure, and whispering gallery mode (WGM) resonances were generated with a 1550 nm tunable laser via an optical fiber taper. Reversible shifts in the WGM resonant wavelength upon vapor exposure were detected with a photodetector. The μOFRR chip was connected to a pair of upstream etched-Si chips containing PDMS-coated separation μcolumns and calibration curves were generated from the peak-area responses to five volatile organic compounds (VOCs). Calibration curves were linear, and the sensitivities reflected the influence of analyte volatility and analyte-MPN functional group affinity. Sorption-induced changes in film thickness apparently dominate over changes in the refractive index of the film as the determinant of responses for all VOCs. Peaks from the MPN-coated μOFRR were just 20-50% wider than those from a flame ionization detector for similar μcolumn separation conditions, reflecting the rapid response of the sensor for VOCs. The five VOCs were baseline separated in <1.67 min, with detection limits as low as 38 ng.

Nanoparticle-coated micro-optofluidic ring resonator as a detector for microscale gas chromatographic vapor analysis

Science.gov (United States)

Scholten, K.; Collin, W. R.; Fan, X.; Zellers, E. T.

2015-05-01

A vapor sensor comprising a nanoparticle-coated microfabricated optofluidic ring resonator (μOFRR) is introduced. A multilayer film of polyether functionalized, thiolate-monolayer-protected gold nanoparticles (MPN) was solvent cast on the inner wall of the hollow cylindrical SiOx μOFRR resonator structure, and whispering gallery mode (WGM) resonances were generated with a 1550 nm tunable laser via an optical fiber taper. Reversible shifts in the WGM resonant wavelength upon vapor exposure were detected with a photodetector. The μOFRR chip was connected to a pair of upstream etched-Si chips containing PDMS-coated separation μcolumns and calibration curves were generated from the peak-area responses to five volatile organic compounds (VOCs). Calibration curves were linear, and the sensitivities reflected the influence of analyte volatility and analyte-MPN functional group affinity. Sorption-induced changes in film thickness apparently dominate over changes in the refractive index of the film as the determinant of responses for all VOCs. Peaks from the MPN-coated μOFRR were just 20-50% wider than those from a flame ionization detector for similar μcolumn separation conditions, reflecting the rapid response of the sensor for VOCs. The five VOCs were baseline separated in <1.67 min, with detection limits as low as 38 ng.

Ultra-Tuning of the Rare-Earth fcu-MOF Aperture Size for Selective Molecular Exclusion of Branched Paraffins.

Science.gov (United States)

Assen, Ayalew H; Belmabkhout, Youssef; Adil, Karim; Bhatt, Prashant M; Xue, Dong-Xu; Jiang, Hao; Eddaoudi, Mohamed

2015-11-23

Using isoreticular chemistry allows the design and construction of a new rare-earth metal (RE) fcu-MOF with a suitable aperture size for practical steric adsorptive separations. The judicious choice of a relatively short organic building block, namely fumarate, to bridge the 12-connected RE hexanuclear clusters has afforded the contraction of the well-defined RE-fcu-MOF triangular window aperture, the sole access to the two interconnected octahedral and tetrahedral cages. The newly constructed RE (Y(3+) and Tb(3+)) fcu-MOF analogues display unprecedented total exclusion of branched paraffins from normal paraffins. The resultant window aperture size of about 4.7 Å, regarded as a sorbate-size cut-off, enabled a complete sieving of branched paraffins from normal paraffins. The results are supported by collective single gas and mixed gas/vapor adsorption and calorimetric studies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tantalum coating on porous Ti6Al4V scaffold using chemical vapor deposition and preliminary biological evaluation

Energy Technology Data Exchange (ETDEWEB)

Li, Xiang, E-mail: xiangliwj@sjtu.edu.cn [School of Mechanical Engineering, Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, Shanghai, 200240 (China); Wang, Lin [Institute of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi' an, 710032 (China); Yu, Xiaoming [The Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 (China); Feng, Yafei [Institute of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi' an, 710032 (China); Wang, Chengtao [School of Mechanical Engineering, Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, Shanghai, 200240 (China); Yang, Ke [The Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 (China); Su, Daniel [School of Mechanical Engineering, Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, Shanghai, 200240 (China)

2013-07-01

Porous tantalum (Ta), produced via chemical vapor deposition (CVD) of commercially pure Ta onto a vitreous carbon, is currently available for use in orthopedic applications. However, the relatively high manufacturing cost and the incapability to produce customized implant using medical image data have limited its application to gain widespread acceptance. In this study, Ta film was deposited on porous Ti6Al4V scaffolds using CVD technique. Digital microscopy and scanning electron microscopy indicated that the Ta coating evenly covered the entire scaffold structure. X-ray diffraction analysis showed that the coating consisted of α and β phases of Ta. Goat mesenchymal stem cells were seeded and cultured on the Ti6Al4V scaffolds with and without coating. The tetrazolium-based colorimetric assay exhibited better cell adhesion and proliferation on Ta-coated scaffolds compared with uncoated scaffolds. The porous scaffolds were subsequently implanted in goats for 12 weeks. Histological analysis revealed similar bone formation around the periphery of the coated and uncoated implants, but bone ingrowth is better within the Ta-coated scaffolds. To demonstrate the ability of producing custom implant for clinical applications via this technology, we designed and fabricated a porous Ti6Al4V scaffold with segmental mandibular shape derived from patient computerized tomography data. - Highlights: • Ta film was coated on porous Ti6Al4V scaffold using chemical vapor deposition. • Tantalum coating allowed for higher levels of cell adhesion and proliferation. • Better new bone formation occurred inside the tantalum-coated scaffolds. • Clinical image data was integrated with EBM to fabricate customized scaffold.

Tantalum coating on porous Ti6Al4V scaffold using chemical vapor deposition and preliminary biological evaluation

International Nuclear Information System (INIS)

Li, Xiang; Wang, Lin; Yu, Xiaoming; Feng, Yafei; Wang, Chengtao; Yang, Ke; Su, Daniel

2013-01-01

Porous tantalum (Ta), produced via chemical vapor deposition (CVD) of commercially pure Ta onto a vitreous carbon, is currently available for use in orthopedic applications. However, the relatively high manufacturing cost and the incapability to produce customized implant using medical image data have limited its application to gain widespread acceptance. In this study, Ta film was deposited on porous Ti6Al4V scaffolds using CVD technique. Digital microscopy and scanning electron microscopy indicated that the Ta coating evenly covered the entire scaffold structure. X-ray diffraction analysis showed that the coating consisted of α and β phases of Ta. Goat mesenchymal stem cells were seeded and cultured on the Ti6Al4V scaffolds with and without coating. The tetrazolium-based colorimetric assay exhibited better cell adhesion and proliferation on Ta-coated scaffolds compared with uncoated scaffolds. The porous scaffolds were subsequently implanted in goats for 12 weeks. Histological analysis revealed similar bone formation around the periphery of the coated and uncoated implants, but bone ingrowth is better within the Ta-coated scaffolds. To demonstrate the ability of producing custom implant for clinical applications via this technology, we designed and fabricated a porous Ti6Al4V scaffold with segmental mandibular shape derived from patient computerized tomography data. - Highlights: • Ta film was coated on porous Ti6Al4V scaffold using chemical vapor deposition. • Tantalum coating allowed for higher levels of cell adhesion and proliferation. • Better new bone formation occurred inside the tantalum-coated scaffolds. • Clinical image data was integrated with EBM to fabricate customized scaffold

Mass spectrometric study of vaporization of cesium tellurate and tellurite

International Nuclear Information System (INIS)

Semenov, G.A.; Fokina, L.A.; Mouldagalieva, R.A.

1994-01-01

The process of vaporization of cesium tellurate and tellurite was studied by the Knudsen effusion method with a mass spectrometric analysis of the vapor composition. The thermal dissociation of Cs 2 TeO 4 to Cs 2 TeO 3 and the congruent vaporization of Cs 2 TeO 3 were established. Thermodynamic functions for gaseous Cs 2 TeO 3 have been calculated. The standard enthalpy of sublimation Δ s H (298.15)=268.1±13.0 kJ mol -1 was determined by the 2nd and 3rd laws of thermodynamics. The enthalpy of formation Δ f H (298.15)=-725.1±13.0 kJ mol -1 for gaseous Cs 2 TeO 3 and the enthalpy of atomization Δ at H (298.15)=1841.3±15.0 kJ mol -1 have been computed. ((orig.))

Water-resistant, monodispersed and stably luminescent CsPbBr3/CsPb2Br5 core-shell-like structure lead halide perovskite nanocrystals

Science.gov (United States)

Qiao, Bo; Song, Pengjie; Cao, Jingyue; Zhao, Suling; Shen, Zhaohui; Gao, Di; Liang, Zhiqin; Xu, Zheng; Song, Dandan; Xu, Xurong

2017-11-01

Lead halide perovskite materials are thriving in optoelectronic applications due to their excellent properties, while their instability due to the fact that they are easily hydrolyzed is still a bottleneck for their potential application. In this work, water-resistant, monodispersed and stably luminescent cesium lead bromine perovskite nanocrystals coated with CsPb2Br5 were obtained using a modified non-stoichiometric solution-phase method. CsPb2Br5 2D layers were coated on the surface of CsPbBr3 nanocrystals and formed a core-shell-like structure in the synthetic processes. The stability of the luminescence of the CsPbBr3 nanocrystals in water and ethanol atmosphere was greatly enhanced by the photoluminescence-inactive CsPb2Br5 coating with a wide bandgap. The water-stable enhanced nanocrystals are suitable for long-term stable optoelectronic applications in the atmosphere.

Simple-design ultra-low phase noise microwave frequency synthesizers for high-performing Cs and Rb vapor-cell atomic clocks

Energy Technology Data Exchange (ETDEWEB)

François, B. [FEMTO-ST, CNRS, Université de Franche-Comté, 26 chemin de l’Epitaphe, 25030 Besançon (France); INRIM, Strada delle Cacce 91, 10135 Torino (Italy); Calosso, C. E.; Micalizio, S. [INRIM, Strada delle Cacce 91, 10135 Torino (Italy); Abdel Hafiz, M.; Boudot, R. [FEMTO-ST, CNRS, Université de Franche-Comté, 26 chemin de l’Epitaphe, 25030 Besançon (France)

2015-09-15

We report on the development and characterization of novel 4.596 GHz and 6.834 GHz microwave frequency synthesizers devoted to be used as local oscillators in high-performance Cs and Rb vapor-cell atomic clocks. The key element of the synthesizers is a custom module that integrates a high spectral purity 100 MHz oven controlled quartz crystal oscillator frequency-multiplied to 1.6 GHz with minor excess noise. Frequency multiplication, division, and mixing stages are then implemented to generate the exact output atomic resonance frequencies. Absolute phase noise performances of the output 4.596 GHz signal are measured to be −109 and −141 dB rad{sup 2}/Hz at 100 Hz and 10 kHz Fourier frequencies, respectively. The phase noise of the 6.834 GHz signal is −105 and −138 dB rad{sup 2}/Hz at 100 Hz and 10 kHz offset frequencies, respectively. The performances of the synthesis chains contribute to the atomic clock short term fractional frequency stability at a level of 3.1 × 10{sup −14} for the Cs cell clock and 2 × 10{sup −14} for the Rb clock at 1 s averaging time. This value is comparable with the clock shot noise limit. We describe the residual phase noise measurements of key components and stages to identify the main limitations of the synthesis chains. The residual frequency stability of synthesis chains is measured to be at the 10{sup −15} level for 1 s integration time. Relevant advantages of the synthesis design, using only commercially available components, are to combine excellent phase noise performances, simple-architecture, low-cost, and to be easily customized for signal output generation at 4.596 GHz or 6.834 GHz for applications to Cs or Rb vapor-cell frequency standards.

Effect of zirconium nitride physical vapor deposition coating on preosteoblast cell adhesion and proliferation onto titanium screws.

Science.gov (United States)

Rizzi, Manuela; Gatti, Giorgio; Migliario, Mario; Marchese, Leonardo; Rocchetti, Vincenzo; Renò, Filippo

2014-11-01

Titanium has long been used to produce dental implants. Problems related to its manufacturing, casting, welding, and ceramic application for dental prostheses still limit its use, which highlights the need for technologic improvements. The aim of this in vitro study was to evaluate the biologic performance of titanium dental implants coated with zirconium nitride in a murine preosteoblast cellular model. The purpose of this study was to evaluate the chemical and morphologic characteristics of titanium implants coated with zirconium nitride by means of physical vapor deposition. Chemical and morphologic characterizations were performed by scanning electron microscopy and energy dispersive x-ray spectroscopy, and the bioactivity of the implants was evaluated by cell-counting experiments. Scanning electron microscopy and energy dispersive x-ray spectroscopy analysis found that physical vapor deposition was effective in covering titanium surfaces with zirconium nitride. Murine MC-3T3 preosteoblasts were seeded onto titanium-coated and zirconium nitride-coated screws to evaluate their adhesion and proliferation. These experiments found a significantly higher number of cells adhering and spreading onto zirconium nitride-coated surfaces (Pzirconium nitride surfaces were completely covered with MC-3T3 cells. Analysis of these data indicates that the proposed zirconium nitride coating of titanium implants could make the surface of the titanium more bioactive than uncoated titanium surfaces. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

[Energy pooling collisions for K(4P) + Cs(5D) in a K-Cs mixture].

Science.gov (United States)

Aihemaiti, Pulati; Dai, Kang; Lu, Xin-hong; Shen, Yi-fan

2005-04-01

The rate coefficients for energy-pooling collisions K(4P) + Cs(5D) --> Cs(6S) + K(4D, 6S) in the K-Cs vapor mixture were measured relative to a known energy-pooling rate coefficient of a homonuclear reaction [i. e., Cs(6P) + Cs(5D) --> Cs(6S) + Cs (7D(J))]. Populations of the Cs(6P, 5D) and K(4P) states were produced by photodissociation of K2 and Cs2 molecules through the use of a dye laser radiation. The resulting fluorescence included the direct components emitted in the decay of the excited states produced by photodissociation and the induced components arising from the collisionally populated states. By combining relative intensities of the components with the effective lifetimes of Cs(6P) and K(4P) states, the rate coefficients (in units of 10(-9) cm3 x s(-1)) for the heteronuclear energy-pooling were found to be 2.6 and 3.6, respectively. The contribution to the rate coefficients from other processes are discussed.

Advantages of infrared transflection micro spectroscopy and paraffin-embedded sample preparation for biological studies

Science.gov (United States)

Yao, Jie; Li, Qian; Zhou, Bo; Wang, Dan; Wu, Rie

2018-04-01

Fourier-Transform Infrared micro-spectroscopy is an excellent method for biological analyses. In this paper, series metal coating films on ITO glass were prepared by the electrochemical method and the different thicknesses of paraffin embedding rat's brain tissue on the substrates were studied by IR micro-spetroscopy in attenuated total reflection (ATR) mode and transflection mode respectively. The Co-Ni-Cu alloy coating film with low cost is good reflection substrates for the IR analysis. The infrared microscopic transflection mode needs not to touch the sample at all and can get the IR spectra with higher signal to noise ratios. The Paraffin-embedding method allows tissues to be stored for a long time for re-analysis to ensure the traceability of the sample. Also it isolates the sample from the metal and avoids the interaction of biological tissue with the metals. The best thickness of the tissues is 4 μm.

Chemical Vapor-Deposited (CVD) Diamond Films for Electronic Applications

Science.gov (United States)

1995-01-01

Diamond films have a variety of useful applications as electron emitters in devices such as magnetrons, electron multipliers, displays, and sensors. Secondary electron emission is the effect in which electrons are emitted from the near surface of a material because of energetic incident electrons. The total secondary yield coefficient, which is the ratio of the number of secondary electrons to the number of incident electrons, generally ranges from 2 to 4 for most materials used in such applications. It was discovered recently at the NASA Lewis Research Center that chemical vapor-deposited (CVD) diamond films have very high secondary electron yields, particularly when they are coated with thin layers of CsI. For CsI-coated diamond films, the total secondary yield coefficient can exceed 60. In addition, diamond films exhibit field emission at fields orders of magnitude lower than for existing state-of-the-art emitters. Present state-of-the-art microfabricated field emitters generally require applied fields above 5x10^7 V/cm. Research on field emission from CVD diamond and high-pressure, high-temperature diamond has shown that field emission can be obtained at fields as low as 2x10^4 V/cm. It has also been shown that thin layers of metals, such as gold, and of alkali halides, such as CsI, can significantly increase field emission and stability. Emitters with nanometer-scale lithography will be able to obtain high-current densities with voltages on the order of only 10 to 15 V.

Accelerated Thermal Cycling Test of Microencapsulated Paraffin Wax/Polyaniline Made by Simple Preparation Method for Solar Thermal Energy Storage.

Science.gov (United States)

Silakhori, Mahyar; Naghavi, Mohammad Sajad; Metselaar, Hendrik Simon Cornelis; Mahlia, Teuku Meurah Indra; Fauzi, Hadi; Mehrali, Mohammad

2013-04-29

Microencapsulated paraffin wax/polyaniline was prepared using a simple in situ polymerization technique, and its performance characteristics were investigated. Weight losses of samples were determined by Thermal Gravimetry Analysis (TGA). The microencapsulated samples with 23% and 49% paraffin showed less decomposition after 330 °C than with higher percentage of paraffin. These samples were then subjected to a thermal cycling test. Thermal properties of microencapsulated paraffin wax were evaluated by Differential Scanning Calorimeter (DSC). Structure stability and compatibility of core and coating materials were also tested by Fourier transform infrared spectrophotometer (FTIR), and the surface morphology of the samples are shown by Field Emission Scanning Electron Microscopy (FESEM). It has been found that the microencapsulated paraffin waxes show little change in the latent heat of fusion and melting temperature after one thousand thermal recycles. Besides, the chemical characteristics and structural profile remained constant after one thousand thermal cycling tests. Therefore, microencapsulated paraffin wax/polyaniline is a stable material that can be used for thermal energy storage systems.

Knudsen cell mass spectrometric study of the Cs2IOH(g) molecule thermodynamics

International Nuclear Information System (INIS)

Roki, F-Z.; Ohnet, M-N.; Fillet, S.; Chatillon, C.; Nuta, I.

2013-01-01

Highlights: • The pronounced ionic character leads to only dissociative ionization processes. • Ions formed are same as those coming from pure dimmers. • De-convolution of the ions origin needs accurate thermodynamic values for the pure gas phase. • Mass spectrometric interpretation has to be performed gradually and as a function of suitable condensed compositions. • Thermal functions have to be fully estimated. -- Abstract: The gas phase of the CsI + CsOH system is analyzed by high temperature Knudsen cell mass spectrometry in order to confirm the existence of the Cs 2 IOH(g) complex molecule. The mass spectrometric analysis is quite complex since such molecules undergo dissociative ionization into fragment ions that mix with the same ions from dimers of the pure compounds in the same vapor phase. Varying the chemical conditions for vaporization by using different CsI + CsOH mixture contents showed that the ionization of the Cs 2 IOH(g) molecule led to five different fragment ions, Cs 2 OH + , Cs 2 I + , Cs + , CsOH + and CsI + . This complex ionization pattern was studied in relation with previous assessed values for the vaporization of CsOH and CsI pure compounds in which monomer and dimer molecules are predominant. The equilibrium constant for the reaction CsI(g) + CsOH(g) = Cs 2 IOH(g) was determined and, after modeling the structure of the Cs 2 IOH molecule, the enthalpy of formation was determined using the third law of thermodynamics, as follows: Δ f H°(Cs 2 IOH, g, 298.15 K) = −578 ± 14.7 kJ · mole −1

Evaluation of corrosion behaviour of tantalum coating obtained by low pressure chemical vapor deposition using electrochemical polarization

Science.gov (United States)

Levesque, A.; Bouteville, A.; de Baynast, H.; Laveissière, B.

2002-06-01

antalum coatings are elaborated on titanium substrates through Low Pressure Chemical Vapor Deposition from tantalum pentachloride-hydrogen gaseous phase at a deposition temperature of 800 °C and a total pressure of 3.3 mbar. The aim of this paper is to evaluate the effectiveness of this tantalum coating in corrosive solution. Optical Microscopy and Scanning Electron Microscopy observations reveal that deposits are of 1.7 μm in thickness and conformal. The corrosion resistance of tantalum coated titanium substrates is quantified through standard potentiodynamic polarization method. Even for tantalum coatings exhibiting some defects as pores, the corrosion current density is as low as 0.25 mA/cm^2.in very agressive solutions like kroll reagent (HN03/HF).

Superconducting magnesium diboride coatings for radio frequency cavities fabricated by hybrid physical-chemical vapor deposition

Science.gov (United States)

Wolak, M. A.; Tan, T.; Krick, A.; Johnson, E.; Hambe, M.; Chen, Ke; Xi, X. X.

2014-01-01

We have investigated the coating of an inner surface of superconducting radio frequency cavities with a magnesium diboride thin film by hybrid physical-chemical vapor deposition (HPCVD). To simulate a 6 GHz rf cavity, a straight stainless steel tube of 1.5-inch inner diameter and a dummy stainless steel cavity were employed, on which small sapphire and metal substrates were mounted at different locations. The MgB2 films on these substrates showed uniformly good superconducting properties including Tc of 37-40 K, residual resistivity ratio of up to 14, and root-mean-square roughness Rq of 20-30 nm. This work demonstrates the feasibility of coating the interior of cylindrical and curved objects with MgB2 by the HPCVD technique, an important step towards superconducting rf cavities with MgB2 coating.

Improved cyclic oxidation resistance of electron beam physical vapor deposited nano-oxide dispersed {beta}-NiAl coatings for Hf-containing superalloy

Energy Technology Data Exchange (ETDEWEB)

Guo Hongbo [School of Materials Science and Engineering, Beihang University, No. 37, Xueyuan Road, Beijing 100191 (China); Beijing Key Laboratory for Advanced Functional Materials and Thin Film Technology, Beihang University, No. 37, Xueyuan Road, Beijing 100191 (China)], E-mail: Guo.hongbo@buaa.edu.cn; Cui Yongjing; Peng Hui; Gong Shengkai [School of Materials Science and Engineering, Beihang University, No. 37, Xueyuan Road, Beijing 100191 (China); Beijing Key Laboratory for Advanced Functional Materials and Thin Film Technology, Beihang University, No. 37, Xueyuan Road, Beijing 100191 (China)

2010-04-15

Oxide dispersed (OD) {beta}-NiAl coatings and OD-free {beta}-NiAl coatings were deposited onto a Hf-containing Ni-based superalloy by electron beam physical vapor deposition (EB-PVD). Excessive enrichment of Hf was found in the TGO on the OD-free coating due to outward diffusion of Hf from the superalloy, causing accelerated TGO thickening and spalling. The OD-coating effectively prevented Hf from outward diffusion. Only small amount of Hf diffused to the coating surface and improved the TGO adherence by virtue of the reactive element effect. The OD-coating exhibited an improved oxidation resistance as compared to the OD-free coating.

Preventing Paraffin-Related Injury

OpenAIRE

C. Schwebel, David; Swart, Dehran

2009-01-01

Paraffin (called kerosene in North America and other parts of the world) is the most commonly used fuel in ‎non-electrified dwellings worldwide. It is especially popular in Africa and South Asia. Although paraffin ‎offers many advantages – especially its comparatively low cost to produce – it poses two major risks of ‎injury. First, paraffin poisoning is common, either through ingestion or through inhalation of smoke and ‎fumes. Second, paraffin is highly flammable, and poses fire risk t...

Environmental sciences: general. 2. Water Adsorption/Absorption by CsOH Particles

International Nuclear Information System (INIS)

Riggs, C.A.; Ghosh, T.K.; Tompson, R.V.; Loyalka, S.K.; Viswanath, D.S.

2001-01-01

Cesium hydroxide in aerosol form is likely to be a significant source of radio-cesium released during a reactor transient. Cesium hydroxide particles are hydrophilic and absorb/adsorb water rapidly. The result is a rapid growth of cesium hydroxide wetted agglomerates that can deposit on surfaces by gravitational settling. However, they can also react with iodine gas to form CsI according to Eq. (1). The rapid absorption/adsorption of water by CsOH may increase the rate of absorption of iodine by CsOH. Iodine may attach itself to adsorbed water molecules on CsOH and facilitate the reaction by bringing iodine to CsOH. Thus, the iodine removal mechanism from the pressurized water reactor containment atmosphere may change: I 2(g) + 4CsOH (s) ↔ 2CsI (s) + 2CsO (s) + 2H 2 O (l) . (1) Despite the importance of CsOH as an aerosol material released during a reactor transient, we have been unable to find any isotherm data of water on cesium hydroxide in the literature. The significant hydrophilic nature of CsOH, together with its being the strongest base currently known, present challenges to collection of water adsorption data. The objective in this research was to experimentally obtain isotherm data of water vapor on CsOH for a range of temperatures and pressures on macroscopic samples using an electro-balance. These data then may be used to predict the amount of water vapor adsorbed on CsOH at other temperatures and pressures by existing models. The adsorption apparatus using a Cahn 2000 electro-balance is shown in Fig. 1. The water adsorption/absorption data on CsOH at different relative pressures of water vapor were obtained gravimetrically. A detailed description of the experimental system is given in Hassan et al. An∼70-mg sample of CsOH.H 2 O (s) was placed onto a platinum weighing dish in the hang-down tube of the balance. The sample was regenerated by heating it at 100 deg. C under a vacuum of 3.5x10 -2 mm Hg for 24 h to remove adsorbed water and other gases

Flammability characteristics of combustible gases and vapors

Energy Technology Data Exchange (ETDEWEB)

Zabetakis, M. G. [Bureau of Mines, Pittsburgh, PA (United States)

1964-05-01

This is a summary of the available limit of flammability, autoignition and burning-rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as of empirical rules and graphs that can be used to predict similar data for thousands of other combustibles under a variety of environmental conditions. Spec$c data are presented on the paraffinic, unsaturated, aromatic, and alicyclic hydrocarbons, alcohols, ethers, aldehydes, ketones, and sulfur compounds, and an assortment of fuels, fuel blends, hydraulic fluids, engine oils, and miscellaneous combustible gases and vapors.

Satellite bands of the RbCs molecule in the range of highly excited states

Energy Technology Data Exchange (ETDEWEB)

Rakić, Mario; Beuc, Robert; Skenderović, Hrvoje, E-mail: hrvoje@ifs.hr [Institute of Physics, Bijenička cesta 46, Zagreb 10000 (Croatia); Bouloufa-Maafa, Nadia; Dulieu, Olivier; Vexiau, Romain [Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Bât. 505, Campus d’Orsay, Orsay Cedex 91405 (France); Pichler, Goran [Physics Department, Kuwait University, PO Box 5969, Safat—13060 (Kuwait)

2016-05-28

We report on the observation of three RbCs satellite bands in the blue and green ranges of the visible spectrum. Absorption measurements are performed using all-sapphire cell filled with a mixture of Rb and Cs. We compare high resolution absorption spectrum of Rb-Cs vapor mixture with pure Rb and Cs vapor spectra from the literature. After detailed analysis, the new satellite bands of RbCs molecule at 418.3 nm, 468.3, and 527.5 nm are identified. The origin of these bands is discussed by direct comparison with difference potentials derived from quantum chemistry calculations of RbCs potential energy curves. These bands originate from the lower Rydberg states of the RbCs molecule. This study thus provides further insight into photoassociation of lower Rydberg molecular states, approximately between Cs(7s) + Rb(5s) and Cs(6s) + Rb(6p) asymptotes, in ultracold gases.

Composite phase change materials prepared by encapsuling paraffin in PVC macrocapsules

International Nuclear Information System (INIS)

Chen, Yingbo; Zhang, Shifeng; Zhang, Qi; Chen, Yusheng; Zhang, Yufeng

2014-01-01

Highlights: • PVC macrocapsules coated with SiO 2 were synthesized. • Paraffin was encapsuled in the capsules. • The composite PCM has high heat capacity. • The composite PCM has no surpercooling. - Abstract: A novel phase change material capsules with SiO 2 in their surface was prepared by absorbing paraffin into PVC hollow capsules and by the polycondensation reaction of TEOS in different conditions. X-ray photoelectron spectroscopy (XPS) analysis and scanning electronic microscope (SEM) were used to determine chemical composition and microstructure of the composite capsules, respectively. Enthalpy capacity and thermal stability of the composite capsules are systematically characterized by using differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA) and thermocycling tests. The composite has high heat capacity with good stability and absence of supercooling phenomena

Evaluation of polymer-coated CsI:Tl as an alpha/beta pulse shape discriminating flow-cell

International Nuclear Information System (INIS)

Branton, S.D.; Fjeld, R.A.; DeVol, T.A.

1996-01-01

A pulse shape discriminating flow-cell radiation detection system constructed with polymer coated CsI:Tl was evaluated for simultaneous gross alpha/gross beta quantification. The CsI:TI scintillator was crushed and sieved to 63-90 μm particle size and microencapsulated with Parylene C to reduce its rate of dissolution. Averaged over the first hour of use, the pulse shape discrimination figure-of-merit was 1.4 and the detection efficiencies were 64.9 ± 5.7 %, 52.5 ± 4.5 % and 4.5 ± 0.2 % for 233 U, 90 Sr/ 90 Y and 14 C , respectively. The typical background count rate in the alpha and beta pulse shape window was 0.17 and 0.004 cps, respectively. The resultant minimum detectable activity for a 30 second count time was calculated to be 0.19 ± 0.01 Bq, 0.9 ± 0.1 Bq and 11.4 ± 0.6 Bq for 233 U, 90 Sr/ 90 Y and 14 C, respectively. Although the 3 μm thick microencapsulation reduced CsI:Tl dissolution, the detection efficiency declined by a factor of two after 4.8 hours while the pulse shape resolution degraded slightly

On the tungsten single crystal coatings achieved by chemical vapor transportation deposition

Energy Technology Data Exchange (ETDEWEB)

Shi, J.Q.; Shen, Y.B.; Yao, S.Y.; Zhang, P.J.; Zhou, Q.; Guo, Y.Z. [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Tan, C.W., E-mail: tanchengwen@bit.edu.cn [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); China Astronaut Research and Training Center, Beijing 100094 (China); Yu, X.D. [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); China Astronaut Research and Training Center, Beijing 100094 (China); Nie, Z.H. [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Ma, H.L. [China Astronaut Research and Training Center, Beijing 100094 (China); Cai, H.N. [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)

2016-12-15

The tungsten single crystal has many excellent properties, namely a high melting point, high anti-creeping strength. Chemical vapor transportation deposition (CVTD) is a possible approach to achieve large-sized W single crystals for high-temperature application such as the cathode of a thermionic energy converter. In this work, CVTD W coatings were deposited on the monocrystalline molybdenum substrate (a tube with < 111 > axial crystalline orientation) using WCl{sub 6} as a transport medium. The microstructures of the coatings were investigated by a scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). The as-deposited coatings are hexagonal prisms—rough surfaces perpendicular to < 110 > with alternating hill-like bulges and pits at the side edges of the prisms, and flat surfaces perpendicular to < 112 > with arc-shaped terraces at the side faces. This can be explained by two-dimensional nucleation -mediated lateral growth model. Some parts of the coatings contain hillocks of an exotic morphology (noted as “abnormal growth”). The authors hypothesize that the abnormal growth is likely caused by the defects of the Mo substrate, which facilitate W nucleation sites, cause orientation difference, and may even form boundaries in the coatings. A dislocation density of 10{sup 6} to 10{sup 7} (counts/cm{sup 2}) was revealed by an etch-pit method and synchrotron X-ray diffraction. As the depositing temperature rises, the dislocation density decreases, and no sub-boundaries are found on samples deposited over 1300 °C, as a result of atom diffusion and dislocation climbing. - Highlights: •The varied growth rate causes the different morphologies of different planes. •The W coating is a single crystal when only single hillocks appear. •The (110) plane tends to have the lowest dislocation density. •The dislocation density tends to decrease as the temperature increases.

On the tungsten single crystal coatings achieved by chemical vapor transportation deposition

International Nuclear Information System (INIS)

Shi, J.Q.; Shen, Y.B.; Yao, S.Y.; Zhang, P.J.; Zhou, Q.; Guo, Y.Z.; Tan, C.W.; Yu, X.D.; Nie, Z.H.; Ma, H.L.; Cai, H.N.

2016-01-01

The tungsten single crystal has many excellent properties, namely a high melting point, high anti-creeping strength. Chemical vapor transportation deposition (CVTD) is a possible approach to achieve large-sized W single crystals for high-temperature application such as the cathode of a thermionic energy converter. In this work, CVTD W coatings were deposited on the monocrystalline molybdenum substrate (a tube with < 111 > axial crystalline orientation) using WCl 6 as a transport medium. The microstructures of the coatings were investigated by a scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). The as-deposited coatings are hexagonal prisms—rough surfaces perpendicular to < 110 > with alternating hill-like bulges and pits at the side edges of the prisms, and flat surfaces perpendicular to < 112 > with arc-shaped terraces at the side faces. This can be explained by two-dimensional nucleation -mediated lateral growth model. Some parts of the coatings contain hillocks of an exotic morphology (noted as “abnormal growth”). The authors hypothesize that the abnormal growth is likely caused by the defects of the Mo substrate, which facilitate W nucleation sites, cause orientation difference, and may even form boundaries in the coatings. A dislocation density of 10 6 to 10 7 (counts/cm 2 ) was revealed by an etch-pit method and synchrotron X-ray diffraction. As the depositing temperature rises, the dislocation density decreases, and no sub-boundaries are found on samples deposited over 1300 °C, as a result of atom diffusion and dislocation climbing. - Highlights: •The varied growth rate causes the different morphologies of different planes. •The W coating is a single crystal when only single hillocks appear. •The (110) plane tends to have the lowest dislocation density. •The dislocation density tends to decrease as the temperature increases.

Superconducting magnesium diboride coatings for radio frequency cavities fabricated by hybrid physical-chemical vapor deposition

Directory of Open Access Journals (Sweden)

M. A. Wolak

2014-01-01

Full Text Available We have investigated the coating of an inner surface of superconducting radio frequency cavities with a magnesium diboride thin film by hybrid physical-chemical vapor deposition (HPCVD. To simulate a 6 GHz rf cavity, a straight stainless steel tube of 1.5-inch inner diameter and a dummy stainless steel cavity were employed, on which small sapphire and metal substrates were mounted at different locations. The MgB_{2} films on these substrates showed uniformly good superconducting properties including T_{c} of 37–40 K, residual resistivity ratio of up to 14, and root-mean-square roughness R_{q} of 20–30 nm. This work demonstrates the feasibility of coating the interior of cylindrical and curved objects with MgB_{2} by the HPCVD technique, an important step towards superconducting rf cavities with MgB_{2} coating.

Biodegradation of paraffin wax by crude Aspergillus enzyme preparations for potential use in removing paraffin deposits.

Science.gov (United States)

Zhang, Junhui; Xue, Quanhong; Gao, Hui; Wang, Ping

2015-11-01

Paraffin deposition problems have plagued the oil industry. Whist mechanical and chemical methods are problematic, microbiological method of paraffin removal is considered an alternative. However, studies have mainly investigated the use of bacteria, with little attention to the potential of fungi. The performance of six Aspergillus isolates to degrade paraffin wax was evaluated under laboratory conditions using solid enzyme preparations. The results showed that all the six enzyme preparations efficiently improved the solubility of paraffin wax in n-hexane and degraded n-alkanes in paraffin wax. The degradation process was accompanied by dynamic production of gases (CO2 and H2 ) and organic acids (oxalate and propionate). The shape of wax crystals markedly changed after enzymatic degradation, with a rough surface and a loose structure. This study indicates that extracellular enzymes from Aspergillus spp. can efficiently degrade paraffin wax. These enzyme preparations have the potential for use in oil wells with paraffin deposition problems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microwave absorption property of the diatomite coated by Fe-CoNiP films

Science.gov (United States)

Yan, Zhenqiang; Cai, Jun; Xu, Yonggang; Zhang, Deyuan

2015-08-01

A bio-absorbent of Fe-CoNiP coated on the diatomite was fabricated by way of electroless plating of CoNiP and subsequent chemical vapor deposition of Fe. The surface morphology and composition of the above-mentioned diatomite particles at different stage were characterized with the scanning electron microscopy and the energy spectrum analysis respectively, and the results showed that the diatomite was successfully coated with CoNoP and Fe (carbony iron). The complex permittivity and permeability of composites filled with the bio-absorbent and paraffin was measured in frequency range of 2-18 GHz, and then the microwave reflection loss (RL) and the shielding effectiveness (SE) were calculated. The results showed that the permittivity and the permeability were both enlarged as Fe films were coated onto the CoNiP-coated diatomite, which was attributed to the excellent electromagnetic property of carbonyl irons. The composites made with the Fe-CoNiP diatomite had a better absorbing property (minimum RL -11.0 dB) as well as the shielding property (maximum SE 5.6 dB) at thickness 2 mm. It indicated the absorption property was mainly due to the attenuation on the microwave, and the Fe-CoNiP diatomite could be an effective absorbent with low-density.

Antimony (Sb) sorption studies on zircaloy, carbon steel (CS) and magnetite coated CS (MCS) surfaces in aqueous medium at pH 10.2 and 280℃

International Nuclear Information System (INIS)

Keny, S.J.; Kumbhar, A.G.; Achary, S.N.; Basu, Saibal

2014-01-01

Antimony sorption studies on zircaloy, CS and magnetite coated carbon steel (MCS) at primary heat transport temperature (290℃) of pressurised heavy water reactor (PHWR) are of direct relevance in investigating Sb activity problem faced in Indian PHWRs. Sb impregnated PHT pump carbon bearing releases Sb to reactor core. This Sb activates, and redeposit on out-of-core surfaces and results in exposure and apparent high decontamination factors. This Sb is not amenable to normal decantation. The form and state of deposited Sb is not yet fully known. This works attempts for this

Coating technologies in the nuclear industry

International Nuclear Information System (INIS)

Kaae, J.L.

1993-01-01

Metallic, ceramic, and organic coatings are so commonly used in modern industry that virtually everyone can name several applications in which coatings are employed. Thus, it is no surprise that coating technologies are widely employed in the nuclear industry. Some of these technologies utilize processes that are mature and well developed, and others utilize processes that are new and state of the art. In this paper, five generic coating processes that include almost all vapor deposition processes are described, and then applications of each of these processes for deposition of specific materials in nuclear applications are described. These latter selections, of course, are very subjective, and others will be able to name other applications. Because of their wide range of application, coating technologies are considered to be national critical technologies. The generic coating processes that cover almost all vapor deposition technologies are as follows: (1) stationary substrate chemical vapor deposition; (2) fluidized bed chemical vapor deposition; (3) plasma-assisted chemical deposition; (4) sputtering; (5) evaporation

Fabrication and properties of iron-based soft magnetic composites coated with parylene via chemical vapor deposition polymerization

International Nuclear Information System (INIS)

Wu, Shen; Sun, Aizhi; Lu, Zhenwen; Cheng, Chuan

2015-01-01

This paper focuses on novel iron-based soft magnetic composites synthesis utilizing low friction factor parylene C films to coat iron powder via chemical vapor deposition polymerization. The morphology, magnetic properties, density, and chemical stability of parylene insulated iron particles were investigated. The coated parylene insulating layer was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The thickness of parylene C film is averagely 300 nm according to the results of transmission electron microscopy. Parylene C film uniformly coated the powder surface resulting in reducing the permeability imaginary part, increasing electrical resistivity and increasing the operating frequency of the synthesized magnets. It was shown that the parylene C coated compacts exhibited noticeably higher density compared to the epoxy resin coated compacts at the same pressure, suppress at 800 MPa increased the density by 17.02%. The result of Tafel curves indicated that the resistance of the iron particles to corrosion by NaCl solution is obviously improved after being insulated with parylene C film. - Highlights: • Parylene C uniformly coated the powder, increased the operating frequency of SMCs. • Compared with epoxy coated, the density of SMCs increased by 17.02% at 800 MPa. • The resistance of the iron particles is obviously improved with parylene film insulated

Thermal barrier coatings of rare earth materials deposited by electron beam-physical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Xu Zhenhua [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); He Limin, E-mail: he_limin@yahoo.co [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Chen Xiaolong; Zhao Yu [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Cao Xueqiang, E-mail: xcao@ciac.jl.c [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2010-10-15

Thermal barrier coatings (TBCs) have very important applications in gas turbines for higher thermal efficiency and protection of components at high temperature. TBCs of rare earth materials such as lanthanum zirconate (La{sub 2}Zr{sub 2}O{sub 7}, LZ), lanthanum cerate (La{sub 2}Ce{sub 2}O{sub 7}, LC), lanthanum cerium zirconate (La{sub 2}(Zr{sub 0.7}Ce{sub 0.3}){sub 2}O{sub 7}, LZ7C3) were prepared by electron beam-physical vapor deposition (EB-PVD). The composition, crystal structure, cross-sectional morphology and cyclic oxidation behavior of these coatings were studied. These coatings have partially deviated from their original compositions due to the different evaporation rates of oxides, and the deviation could be reduced by properly controlling the deposition condition. A double ceramic layer-thermal barrier coatings (DCL-TBCs) of LZ7C3 and LC could also be deposited with a single LZ7C3 ingot by properly controlling the deposition energy. LaAlO{sub 3} is formed due to the chemical reaction between LC and Al{sub 2}O{sub 3} in the thermally grown oxide (TGO) layer. The failure of DCL-TBCs is a result of the sintering-induced of LZ7C3 coating and the chemical incompatibility of LC and TGO. Since no single material that has been studied so far satisfies all the requirements for high temperature applications, DCL-TBCs are an important development direction of TBCs.

A SIMPLE PARAFFIN EMBEDDED PROTOCOL FOR FISH EGG, EMBRYO, AND LARVAE

Directory of Open Access Journals (Sweden)

Gratiana Eka Wijayanti

2017-06-01

Full Text Available This paper describes a simple protocol of paraffin-embedded histological section for fish eggs, embryo and larvae of the hard-lipped barb and the giant gourami. The specimens were fixed in Bouin solution, washed in 70% ethanol, then were dehydrated in a series of ethanol solution of increasing concentration until absolute ethanol was reached. The specimens were cleared in graded xylene and were infiltrated with liquid paraffin then were embedded in pure paraffin. Upon sectioning, at 4–5 µm thick the specimens were attached to the gelatin-coated glass slide and let to dry at room temperature or 37°C overnight. The specimens were deparaffinized in xylene, rehydrated then were stained with hematoxylin and eosin. After being dehydrated in graded ethanol, the specimens were cleared in xylene and were mounted with an organic mounting agent. Any step in preparing histological section including samples collection, fixation, dehydration, infiltration and embedding might contribute to the quality of histological features. A proper knowledge of the tissues beeing processed, fixative solution and the histological techniques is essential to gain good results. Bouin fixative is preferable to fix fish larvae and produce a good histological feature. Decalcification is necessary to produce a good histological section on the specimens containing bone.

Nitrous Oxide/Paraffin Hybrid Rocket Engines

Science.gov (United States)

Zubrin, Robert; Snyder, Gary

2010-01-01

Nitrous oxide/paraffin (N2OP) hybrid rocket engines have been invented as alternatives to other rocket engines especially those that burn granular, rubbery solid fuels consisting largely of hydroxyl- terminated polybutadiene (HTPB). Originally intended for use in launching spacecraft, these engines would also be suitable for terrestrial use in rocket-assisted takeoff of small airplanes. The main novel features of these engines are (1) the use of reinforced paraffin as the fuel and (2) the use of nitrous oxide as the oxidizer. Hybrid (solid-fuel/fluid-oxidizer) rocket engines offer advantages of safety and simplicity over fluid-bipropellant (fluid-fuel/fluid-oxidizer) rocket en - gines, but the thrusts of HTPB-based hybrid rocket engines are limited by the low regression rates of the fuel grains. Paraffin used as a solid fuel has a regression rate about 4 times that of HTPB, but pure paraffin fuel grains soften when heated; hence, paraffin fuel grains can, potentially, slump during firing. In a hybrid engine of the present type, the paraffin is molded into a 3-volume-percent graphite sponge or similar carbon matrix, which supports the paraffin against slumping during firing. In addition, because the carbon matrix material burns along with the paraffin, engine performance is not appreciably degraded by use of the matrix.

Conformal coating of amorphous silicon and germanium by high pressure chemical vapor deposition for photovoltaic fabrics

Science.gov (United States)

Ji, Xiaoyu; Cheng, Hiu Yan; Grede, Alex J.; Molina, Alex; Talreja, Disha; Mohney, Suzanne E.; Giebink, Noel C.; Badding, John V.; Gopalan, Venkatraman

2018-04-01

Conformally coating textured, high surface area substrates with high quality semiconductors is challenging. Here, we show that a high pressure chemical vapor deposition process can be employed to conformally coat the individual fibers of several types of flexible fabrics (cotton, carbon, steel) with electronically or optoelectronically active materials. The high pressure (˜30 MPa) significantly increases the deposition rate at low temperatures. As a result, it becomes possible to deposit technologically important hydrogenated amorphous silicon (a-Si:H) from silane by a simple and very practical pyrolysis process without the use of plasma, photochemical, hot-wire, or other forms of activation. By confining gas phase reactions in microscale reactors, we show that the formation of undesired particles is inhibited within the microscale spaces between the individual wires in the fabric structures. Such a conformal coating approach enables the direct fabrication of hydrogenated amorphous silicon-based Schottky junction devices on a stainless steel fabric functioning as a solar fabric.

Dependence of EIA spectra on mutual coherence between coupling and probe fields in Cs atomic vapors

Energy Technology Data Exchange (ETDEWEB)

Kwon, Mi Rang; Kim, Kyoung Dae; Park, Hyun Deok; Kim, Jung Bog [Korea National University of Education, Chungwon (Korea, Republic of); Moon, Han Seb [Korea Research Institute of the Standards and Science, Taejon (Korea, Republic of)

2002-03-01

We observed the dependence of EIA spectra on the mutual coherence between the coupling and the probe fields in the D{sub 2}F{sub 9} = 4 {r_reversible} F{sub e} = 5 transition of Cs vapors at room temperature where the coupling and the probe fields were made from one laser source or two independent laser sources. By using one source having a high mutual coherence, we found EIA spectra linewidths much narrower than 0.1 {gamma} on the weak coupling field and the transparent spectra with linewidths narrower than 1 MHz within subnatural absorption on the strong coupling field. On the other hand, where the two sources which were nearly incoherent with each other were used, the absorption profiles showed the same dependence on the coupling power as the spectra for the one source, but their linewidths were broad, on the order of the natural linewidth.

Preparation and characterization of underwater superoleophobic chitosan/poly(vinyl alcohol) coatings for self-cleaning and oil/water separation

International Nuclear Information System (INIS)

Wang, Qian; Fu, Youjia; Yan, Xiaoxia; Chang, Yanjiao; Ren, Lili; Zhou, Jiang

2017-01-01

Highlights: • Underwater superoleophobic CS/PVA coatings were prepared using a facile method. • Immersion in NaOH solution was crucial to enhance roughness of the coating surface. • Effects of coating composition on wettability of coating surface were investigated. • The CS/PVA coatings possess self-cleaning property. • The CS/PVA coatings can be used for oil/water separation with high efficiency. - Abstract: In this paper, chitosan (CS)/poly(vinyl alcohol) (PVA) coatings cross-linked with glutaraldehyde (GA) were prepared. Effects of the coating composition and NaOH solution treatment on surface morphology and topography were investigated by scanning electron microscope and atomic force microscope. It was found that the process of immersing the CS/PVA coatings into NaOH solution was crucial to enhance rough structure on the coating surface. The rough surface structure and the hydrophilic groups of CS and PVA made the CS/PVA coatings possess underwater superoleophobicity and low adhesion to oil. Oil contact angle of the prepared CS/PVA coatings was up to 161° and slide angle was only 3°. Moreover, the CS/PVA coatings showed stable superoleophobicity in high salt, strong acidic, and alkaline environments as well as underwater self-cleaning property and excellent transparency. The CS/PVA coatings could be used for gravity driven oil/water separation with high efficiency.

Preparation and characterization of underwater superoleophobic chitosan/poly(vinyl alcohol) coatings for self-cleaning and oil/water separation

Energy Technology Data Exchange (ETDEWEB)

Wang, Qian; Fu, Youjia; Yan, Xiaoxia; Chang, Yanjiao; Ren, Lili; Zhou, Jiang

2017-08-01

Highlights: • Underwater superoleophobic CS/PVA coatings were prepared using a facile method. • Immersion in NaOH solution was crucial to enhance roughness of the coating surface. • Effects of coating composition on wettability of coating surface were investigated. • The CS/PVA coatings possess self-cleaning property. • The CS/PVA coatings can be used for oil/water separation with high efficiency. - Abstract: In this paper, chitosan (CS)/poly(vinyl alcohol) (PVA) coatings cross-linked with glutaraldehyde (GA) were prepared. Effects of the coating composition and NaOH solution treatment on surface morphology and topography were investigated by scanning electron microscope and atomic force microscope. It was found that the process of immersing the CS/PVA coatings into NaOH solution was crucial to enhance rough structure on the coating surface. The rough surface structure and the hydrophilic groups of CS and PVA made the CS/PVA coatings possess underwater superoleophobicity and low adhesion to oil. Oil contact angle of the prepared CS/PVA coatings was up to 161° and slide angle was only 3°. Moreover, the CS/PVA coatings showed stable superoleophobicity in high salt, strong acidic, and alkaline environments as well as underwater self-cleaning property and excellent transparency. The CS/PVA coatings could be used for gravity driven oil/water separation with high efficiency.

Highly stable CsPbBr3 quantum dots coated with alkyl phosphate for white light-emitting diodes.

Science.gov (United States)

Xuan, Tongtong; Yang, Xianfeng; Lou, Sunqi; Huang, Junjian; Liu, Yong; Yu, Jinbo; Li, Huili; Wong, Ka-Leung; Wang, Chengxin; Wang, Jing

2017-10-19

Inorganic halide perovskite quantum dots (QDs) suffer from problems related to poor water stability and poor thermal stability. Here we developed a simple strategy to synthesize alkyl phosphate (TDPA) coated CsPbBr 3 QDs by using 1-tetradecylphosphonic acid both as the ligand for the CsPbBr 3 QDs and as the precursor for the formation of alkyl phosphate. These QDs not only retain a high photoluminescence quantum yield (PLQY, 68%) and narrow band emission (FHWM ∼ 22 nm) but also exhibit high stability against water and heat. The relative PL intensity of the QDs was maintained at 75% or 59% after being dispersed in water for 5 h or heated to 375 K (100 °C), respectively. Finally, white light-emitting diodes (WLEDs) with a high luminous efficiency of 63 lm W -1 and a wide color gamut (122% of NTSC) were fabricated by using green-emitting CsPbBr 3 /TDPA QDs and red-emitting K 2 SiF 6 :Mn 4+ phosphors as color converters. The luminous efficiency of the WLEDs remained at 90% after working under a relative humidity (RH) of 60% for 15 h, thereby showing promise for use as backlight devices in LCDs.

Development of paraffin and paraffin/bitumen composites with additions of B2O3 for thermal neutron shielding applications

International Nuclear Information System (INIS)

Toyen, Donruedee; Saenboonruang, Kiadtisak

2017-01-01

In this work, paraffin and paraffin/bitumen composites with additions of boron oxide (B 2 O 3 ) were prepared to evaluate the viscosity, flexural, and thermal neutron shielding properties for uses as thermal neutron shielding materials. The results showed that the addition of 3 wt% or 9 wt% bitumen to paraffin increased the overall flexural properties with the content of 9 wt% bitumen having the highest values. The improvement in flexural properties made the composites less brittle, stiffer, and longer-lasting. Furthermore, different contents of B 2 O 3 (0, 7, 14, 21, 28, and 35 wt%) were added to paraffin and paraffin/bitumen composites to investigate the effects of the B 2 O 3 contents. The results indicated that an increase in B 2 O 3 contents improved the shielding properties but slightly reduced the flexural properties. Specifically for 5-mm paraffin and 5-mm paraffin/bitumen samples with 35 wt% of B 2 O 3 , both samples could reduce neutron flux by more than 70%. The overall results suggested that the paraffin and paraffin/bitumen composites with additions of B 2 O 3 showed improved properties for utilization as effective thermal neutron shielding materials. (author)

Laser energy-pooling processes in an optically thick Cs vapor near a dissipative surface

International Nuclear Information System (INIS)

Gagne, Jean-Marie; Le Bris, Karine; Gagne, Marie-Claude

2002-01-01

We characterize, for the first time to our knowledge, the laser-induced backward fluorescence (retrofluorescence) spectra that result from energy-pooling collisions between Cs atoms near a dissipative thin Cs layer on a glass substrate. We resolve, experimentally and theoretically, the laser spectroscopic problem of energy-pooling processes related to the nature of the glass-metallic vapor interface. Our study focused on the integrated laser-induced retrofluorescence spectra for the 455.5-nm (7 2 P 3/2 -6 2 S 1/2 ) and 852.2-nm (6 2 P 3/2 -6 2 S 1/2 ) lines as a function of laser scanning through pumping resonance at the 852.2-nm line. We experimentally investigate the retrofluorescence from 420 to 930 nm, induced by a diode laser tuned either in the wings or in the center of the pumping resonance line. We present a detailed theoretical model of the retrofluorescence signal based on the radiative transfer equation, taking into account the evanescent wave of the excited atomic dipole strongly coupled with a dissipative surface. Based on theoretical and experimental results, we evaluate the effective nonradiative transfer rate A(bar sign) 6 2 P 3/2 →6 2 S 1/2s f for atoms in the excited 6 2 P 3/2 level located in the near-field region of the surface of the cell. Values extracted from the energy-pooling process analysis are equivalent to those found directly from the 852.2-nm resonance retrofluorescence line. We show that the effective energy-pooling coefficients k-tilde 7 2 P 3/2 and k-tilde 7 2 P 1/2 are approximately equal. The agreement between theory and experiment is remarkably good, considering the simplicity of the model

Paraffin ingestion - the problem

African Journals Online (AJOL)

The incidence of paraffin ingestion is higher in the summer months. This is because ... where the average cost per patient was R348 per day. The total cost to ... petroleum companies and/or entrepreneurs and distributed ... paraffin, coal and gas. As South Africa ... and more people become involved, making control difficult.

Eudragit ® FS 30 D polymeric films containing chondroitin sulfate as candidates for use in coating seeking modified delivery of drugs

Directory of Open Access Journals (Sweden)

Camila Borges dos Reis

Full Text Available ABSTRACT Polymeric films associating different concentrations of Eudragit(r FS 30 D (EFS and chondroitin sulfate (CS were produced by casting for the development of a new target-specific site material. Formed films kept a final polymer mass of 4% (w/v in the following proportions: EFS 100:00 CS (control, EFS 95:05 CS, EFS 90:10 CS and EFS 80:20 CS. They were analyzed for physical and chemical characteristics using Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM and Raman spectroscopy. Furthermore, they were characterized by their water vapor permeability and degree of hydration at different conditions simulating the gastrointestinal tract. No chemical interactions were observed between CS and EFS, suggesting only a physical interaction between them in the different combinations tested. The results suggest that EFS and CS, when combined, may form films that are candidates for coating processes seeking a modified drug delivery, especially due to the synergism between pH dependency and specific biodegradability properties by the colonic microbiota. EFS 90:10 CS proved to be the most suitable for this purpose considering hydration and permeability characteristics of different associations analyzed.

Properties of plasma assisted chemical vapor deposited coatings of titanium boride on Ti--6Al--4V alloy substrates

International Nuclear Information System (INIS)

Otter, F.A.; Amisola, G.B.; Roman, W.C.; Hay, S.O.

1992-01-01

Coatings prepared in a radio-frequency-plasma (plasma assisted chemical vapor deposition) reactor employing in situ laser diagnostics have been tested and characterized. Detailed characterization studies are important to relate gas phase laser diagnostic studies and concurrent heterogeneous modeling efforts to coating characteristics. Establishing how deposition conditions are correlated with coating properties is expected to provide needed methodology for scale up of applications in the hard face protective coating area. After a brief discussion of preparation conditions and mechanical test results, we present results of chemical and physical measurements on these coatings. Measurement techniques include x-ray diffraction, Dektak surface roughness, scanning tunneling microscopy, scanning electron microscopy, and SEI, Auger electron spectroscopy, x-ray photoelectron spectroscopy, and Rutherford backscattering spectroscopy. The coatings (∼20 μm thick) are very hard (40 GPa at depths over 100 nm), adherent (60 N on scratch test), and sand erosion resistant (>40x as durable as Ti-6Al-4V). They are highly oriented with the c axis (hexagonal-close-packed) normal to the coating surface, rough (∼1 μm), and off-stoichiometry (TiB 2.2 )

21 CFR 890.5110 - Paraffin bath.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Paraffin bath. 890.5110 Section 890.5110 Food and... PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5110 Paraffin bath. (a) Identification. A paraffin bath is a device intended for medical purposes that consists of a tub to be filled...

Chemical stability and osteogenic activity of plasma-sprayed boron-modified calcium silicate-based coatings.

Science.gov (United States)

Lu, Xiang; Li, Kai; Xie, Youtao; Huang, Liping; Zheng, Xuebin

2016-11-01

In recent years, CaSiO 3 bio-ceramic coatings have attracted great attention because of their good bioactivity. However, their high degradation rates in physiological environment restrict their practical applications. In this work, boron-modified CaSiO 3 ceramic (Ca 11 Si 4 B 2 O 22 , B-CS) coating was developed on Ti substrates by plasma-spraying technique attempting to obtain enhanced chemical stability and osteogenic activity. The B-CS coating possessed significantly increased chemical stability due to the introduction of boron and consequently the modified crystal structure, while maintaining good bioactivity. Scanning electron microscope and immunofluorescence studies showed that better cellular adhesion and extinctive filopodia-like processes were observed on the B-CS coating. Compared with the pure CaSiO 3 (CS) coating, the B-CS coating promoted MC3T3-E1 cells attachment and proliferation. In addition, enhanced collagen I (COL-I) secretion, alkaline phosphatase activity, and extracellular matrix mineralization levels were detected from the B-CS coating. According to RT-PCR results, notable up-regulation expressions of mineralized tissue-related genes, such as runt-related transcription factor 2 (Runx2), bone sialoprotein and osteocalcin, and bone morphogenetic protein 7 (BMP-7) were observed on the B-CS coating compared with the CS coating. The above results suggested that Ca 11 Si 4 B 2 O 22 coatings possess excellent osteogenic activity and might be a promising candidate for orthopedic applications.

Microfilms packaging and coating: effects on shelf life and quality of ...

African Journals Online (AJOL)

Studies on storage potential of African pear fruits (APFs) were conducted using three packaging microfilms (low density polyethylene, low density polypropylene and highdensity polypropylene) and three coating materials (sheanut butter, palm oil and paraffin wax). The packaged and coated APFs were separately stored at ...

Multifunctionality in coating films including Nb-doped TiO2 and Cs x WO3: near infrared shielding and photocatalytic properties

Science.gov (United States)

Asakura, Yusuke; Anada, Yuto; Hamanaka, Ryo; Sato, Tsugio; Katsumata, Ken-ichi; Wu, Xiaoyong; Yin, Shu

2018-06-01

Various types of coating films were obtained from hydrothermally synthesized Nb-doped TiO2 (NTO) and Cs x WO3 (CWO) nanoparticles. The coating films possessed multifunctionality including near infrared (NIR) absorption and photocatalysis abilities. The NTO and CWO nanoparticles were synthesized by a unique solvothermal reaction in which water induced by an esterification reaction between alcohol and carboxylic acid can act as a hydrolyzing agent for metal precursors. NTO was synthesized by the unique solvothermal reaction for the first time. The reaction accompanied by the reduction of Ti4+ to Ti3+ led to the formation of nanoparticles with both NIR absorption and photocatalytic properties. The effect of the ethanol–acetic acid ratio on the morphology of the obtained NTO was investigated, and the larger amount of acetic acid led to a larger nanoparticle size, indicating the size controllability. The two types of coating film, including CWO and NTO nanoparticles, were obtained for comparison: (1) coexistent coating film: one side of the quartz glass was coated with a dispersion, including both CWO and NTO nanoparticles, and (2) double-sided coating film: a quartz glass coated with a CWO dispersion on one side and an NTO dispersion on the other side. The double-sided coating led to higher multifunctionality. Furthermore, the optimized condition for the double-sided coating was investigated by using various NTO particles obtained using different ethanol–acetic acid ratios.

Preparation of Ti species coating hydrotalcite by chemical vapor deposition for photodegradation of azo dye.

Science.gov (United States)

Xiao, Gaofei; Zeng, HongYan; Xu, Sheng; Chen, ChaoRong; Zhao, Quan; Liu, XiaoJun

2017-10-01

TiO 2 in anatase crystal phase is a very effective catalyst in the photocatalytic oxidation of organic compounds in water. To improve its photocatalytic activity, the Ti-coating MgAl hydrotalcite (Ti-MgAl-LDH) was prepared by chemical vapor deposition (CVD) method. Response surface method (RSM) was employed to evaluate the effect of Ti species coating parameters on the photocatalytic activity, which was found to be affected by the furnace temperature, N 2 flow rate and influx time of precursor gas. Application of RSM successfully increased the photocatalytic efficiency of the Ti-MgAl-LDH in methylene blue photodegradation under UV irradiation, leading to improved economy of the process. According to the results from X-ray diffraction, scanning electron microscopy, Brunner-Emmet-Teller and Barrett-Joyner-Hallender, thermogravimetric and differential thermal analysis, UV-vis diffuse reflectance spectra analyses, the Ti species (TiO 2 or/and Ti 4+ ) were successfully coated on the MgAl-LDH matrix. The Ti species on the surface of the Ti-MgAl-LDH lead to a higher photocatalytic performance than commercial TiO 2 -P25. The results suggested that CVD method provided a new approach for the industrial preparation of Ti-coating MgAl-LDH material with good photocatalytic performances. Copyright © 2017. Published by Elsevier B.V.

Topical analgesic added to paraffin enhances paraffin bath treatment of individuals with hand osteoarthritis.

Science.gov (United States)

Myrer, Joseph William; Johnson, Aaron Wayne; Mitchell, Ulrike H; Measom, Gary J; Fellingham, Gilbert W

2011-01-01

To compare treating patients with symptomatic hand osteoarthritis (OA) with paraffin baths only (PO) (100% wax) or paraffin baths 80% wax with 20% topical analgesic (PTA). Subjects met criteria of the American College of Rheumatology for classifying symptomatic hand OA and had a Dreiser's index score >5 points. Current and average pain at rest and with movement was assessed with visual analogue scales. Hand function was assessed by the functional index for hand OA (FIHOA). Both groups had a significant reduction in their 'current' pain 15 min after the first and twelfth treatments compared to pre-treatment but there was no difference between groups (t = 0.10, p > 0.05). The PTA group had greater improvement over the 12 treatment sessions for their pain at rest (t = 2.92, p paraffin produced significantly greater pain relief at rest and during movement than paraffin baths alone after 12 treatments. Additionally, the PTA group experienced greater improved hand function.

Enhanced colonic delivery of ciclosporin A self-emulsifying drug delivery system encapsulated in coated minispheres.

Science.gov (United States)

Keohane, Kieran; Rosa, Mónica; Coulter, Ivan S; Griffin, Brendan T

2016-01-01

Investigate the potential of coated minispheres (SmPill®) to enhance localized Ciclosporin A (CsA) delivery to the colon. CsA self-emulsifying drug delivery systems (SEDDS) were encapsulated into SmPill® minispheres. Varying degrees of coating thickness (low, medium and high) were applied using ethylcellulose and pectin (E:P) polymers. In vitro CsA release was evaluated in simulated gastric and intestinal media. Bioavailability of CsA in vivo following oral administration to pigs of SmPill® minispheres was compared to Neoral® po and Sandimmun® iv in a pig model. CsA concentrations in blood and intestinal tissue were determined by HPLC-UV. In vitro CsA release from coated minispheres decreased with increasing coating thickness. A linear relationship was observed between in vitro CsA release and in vivo bioavailability (r(2) = 0.98). CsA concentrations in the proximal, transverse and distal colon were significantly higher following administration of SmPill®, compared to Neoral® po and Sandimmun® iv (p < 0.05). Analysis of transverse colon tissue subsections also revealed significantly higher CsA concentrations in the mucosa and submucosa using SmPill® minispheres (p < 0.05). Modulating E:P coating thickness controls release of CsA from SmPill® minispheres. Coated minispheres limited CsA release in the small intestine and enhanced delivery and uptake in the colon. These findings demonstrate clinical advantages of an oral coated minisphere-enabled CsA formulation in the treatment of inflammatory conditions of the large intestine.

Tensile test of a silicon microstructure fully coated with submicrometer-thick diamond like carbon film using plasma enhanced chemical vapor deposition method

Science.gov (United States)

Zhang, Wenlei; Uesugi, Akio; Hirai, Yoshikazu; Tsuchiya, Toshiyuki; Tabata, Osamu

2017-06-01

This paper reports the tensile properties of single-crystal silicon (SCS) microstructures fully coated with sub-micrometer thick diamond like carbon (DLC) film using plasma enhanced chemical vapor deposition (PECVD). To minimize the deformations or damages caused by non-uniform coating of DLC, which has high compression residual stress, released SCS specimens with the dimensions of 120 µm long, 4 µm wide, and 5 µm thick were coated from the top and bottom side simultaneously. The thickness of DLC coating is around 150 nm and three different bias voltages were used for deposition. The tensile strength improved from 13.4 to 53.5% with the increasing of negative bias voltage. In addition, the deviation in strength also reduced significantly compared to bare SCS sample.

Deposition characteristics of titanium coating deposited on SiC fiber by cold-wall chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Luo, Xian, E-mail: luo_shenfan@hotmail.com; Wu, Shuai; Yang, Yan-qing; Jin, Na; Liu, Shuai; Huang, Bin

2016-12-01

The deposition characteristics of titanium coating on SiC fiber using TiCl{sub 4}-H{sub 2}-Ar gas mixture in a cold-wall chemical vapor deposition were studied by the combination of thermodynamic analysis and experimental studies. The thermodynamic analysis of the reactions in the TiCl{sub 4}-H{sub 2}-Ar system indicates that TiCl{sub 4} transforms to titanium as the following paths: TiCl{sub 4} → TiCl{sub 3} → Ti, or TiCl{sub 4} → TiCl{sub 3} → TiCl{sub 2} → Ti. The experimental results show that typical deposited coating contains two distinct layers: a TiC reaction layer close to SiC fiber and titanium coating which has an atomic percentage of titanium more than 70% and that of carbon lower than 30%. The results illustrate that a carbon diffusion barrier coating needs to be deposited if pure titanium is to be prepared. The deposition rate increases with the increase of temperature, but higher temperature has a negative effect on the surface uniformity of titanium coating. In addition, appropriate argon gas flow rate has a positive effect on smoothing the surface morphology of the coating. - Highlights: • Both thermodynamic analysis and experimental studies were adopted in this work. • The transformation paths of TiCl{sub 4} to Ti is: TiCl{sub 4} → TiCl{sub 3} → Ti, or TiCl{sub 4} → TiCl{sub 3} → TiCl{sub 2} → Ti. • Typical deposited Ti coating on SiC fiber contained two distinct layers. • Deposition temperature is important on deposition rate and morphologies. • Appropriate argon gas flow rate has a positive effect on smoothing of the coating.

Calculation of Physicochemical Properties for Short- and Medium-Chain Chlorinated Paraffins

Science.gov (United States)

Glüge, Juliane; Bogdal, Christian; Scheringer, Martin; Buser, Andreas M.; Hungerbühler, Konrad

2013-06-01

Short- and medium-chain chlorinated paraffins are potential PBT chemicals (persistent, bioaccumulative, toxic) and short-chain chlorinated paraffins are under review for inclusion in the UNEP Stockholm Convention on Persistent Organic Pollutants. Despite their high production volume of more than one million metric tonnes per year, only few data on their physicochemical properties are available. We calculated subcooled-liquid vapor pressure, subcooled-liquid solubility in water and octanol, Henry's law constant for water and octanol, as well as the octanol-water partition coefficient with the property calculation methods COSMOtherm, SPARC, and EPI Suite™, and compared the results to experimental data from the literature. For all properties, good or very good agreement between calculated and measured data was obtained for COSMOtherm; results from SPARC were in good agreement with the measured data except for subcooled-liquid water solubility, whereas EPI Suite™ showed the largest discrepancies for all properties. After critical evaluation of the three property calculation methods, a final set of recommended property data for short- and medium-chain chlorinated paraffins was derived. The calculated property data show interesting relationships with chlorine content and carbon chain length. Increasing chlorine content does not cause pronounced changes in water solubility and octanol-water partition coefficient (KOW) as long as it is below 55%. Increasing carbon chain length leads to strong increases in KOW and corresponding decreases in subcooled-liquid water solubility. The present data set can be used in further studies to assess the environmental fate and human exposure of this relevant compound class.

Anticorrosive effects and in vitro cytocompatibility of calcium silicate/zinc-doped hydroxyapatite composite coatings on titanium

Energy Technology Data Exchange (ETDEWEB)

Huang, Yong, E-mail: xfpang@aliyun.com [College of Lab Medicine, Hebei North University, Zhangjiakou 075000 (China); Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zhang, Honglei [College of Chemistry Environmental Science, Hebei University, Baoding 071000 (China); Qiao, Haixia; Nian, Xiaofeng [College of Lab Medicine, Hebei North University, Zhangjiakou 075000 (China); Zhang, Xuejiao, E-mail: 527238610@qq.com [College of Lab Medicine, Hebei North University, Zhangjiakou 075000 (China); Wang, Wendong; Zhang, Xiaoyun; Chang, Xiaotong [College of Lab Medicine, Hebei North University, Zhangjiakou 075000 (China); Han, Shuguang [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Pang, Xiaofeng [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); International Centre for Materials Physics, Chinese Academy of Science, Shenyang 110015 (China)

2015-12-01

Highlights: • We developed a ZnHA/CS-coated Ti implant by using an ED method. • The obtained ZnHA/CS coatings presented a net-like micro-porous. • The ZnHA/CS coating possessed an excellent corrosion protection ability. • The composite coated CP-Ti possesses favourable cytocompatibility. - Abstract: This work elucidated the corrosion resistance and cytocompatibility of electroplated Zn- and Si-containing bioactive calcium silicate/zinc-doped hydroxyapatite (ZnHA/CS) ceramic coatings on commercially pure titanium (CP-Ti). The formation of ZnHA/CS coating was investigated through Fourier transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, energy dispersive X-ray and inductively coupled plasma analyses. The XRD image showed that the reaction layer was mainly composed of HA and CaSiO{sub 3}. The fabricated ZnHA/CS coatings presented a porous structure and appropriate thickness for possible applications in orthopaedic surgery. Potentiodynamic polarization tests showed that ZnHA/CS coatings exhibited higher corrosion resistance than CP-Ti. Dissolution tests on the coating also revealed that Si{sup 4+} and Zn{sup 2+} were leached at low levels. Moreover, MC3T3-E1 cells cultured on ZnHA/CS featured improved cell morphology, adhesion, spreading, proliferation and expression of alkaline phosphatase than those cultured on HA. The high cytocompatibility of ZnHA/CS could be mainly attributed to the combination of micro-porous surface effects and ion release (Zn{sup 2+} and Si{sup 4+}). All these results indicate that ZnHA/CS composite-coated CP-Ti may be a potential material for orthopaedic applications.

TULSA UNIVERSITY PARAFFIN DEPOSITION PROJECTS

Energy Technology Data Exchange (ETDEWEB)

Cem Sarica; Michael Volk

2004-06-01

As oil and gas production moves to deeper and colder water, subsea multiphase production systems become critical for economic feasibility. It will also become increasingly imperative to adequately identify the conditions for paraffin precipitation and predict paraffin deposition rates to optimize the design and operation of these multi-phase production systems. Although several oil companies have paraffin deposition predictive capabilities for single-phase oil flow, these predictive capabilities are not suitable for the multiphase flow conditions encountered in most flowlines and wellbores. For deepwater applications in the Gulf of Mexico, it is likely that multiphase production streams consisting of crude oil, produced water and gas will be transported in a single multiphase pipeline to minimize capital cost and complexity at the mudline. Existing single-phase (crude oil) paraffin deposition predictive tools are clearly inadequate to accurately design these pipelines, because they do not account for the second and third phases, namely, produced water and gas. The objective of this program is to utilize the current test facilities at The University of Tulsa, as well as member company expertise, to accomplish the following: enhance our understanding of paraffin deposition in single and two-phase (gas-oil) flows; conduct focused experiments to better understand various aspects of deposition physics; and, utilize knowledge gained from experimental modeling studies to enhance the computer programs developed in the previous JIP for predicting paraffin deposition in single and two-phase flow environments. These refined computer models will then be tested against field data from member company pipelines.

Microwave absorption property of the diatomite coated by Fe-CoNiP films

International Nuclear Information System (INIS)

Yan, Zhenqiang; Cai, Jun; Xu, Yonggang; Zhang, Deyuan

2015-01-01

Highlights: • The bio-absorbent coated Fe-CoNiP was fabricated by electroless and CVD. • The EM parameters were enlarged as Fe coated on the diatomite. • The coating CIPs play a key role in the enhancement mechanism. • The Fe-CoNiP diatomite had a better absorbing and shielding properties. - Abstract: A bio-absorbent of Fe-CoNiP coated on the diatomite was fabricated by way of electroless plating of CoNiP and subsequent chemical vapor deposition of Fe. The surface morphology and composition of the above-mentioned diatomite particles at different stage were characterized with the scanning electron microscopy and the energy spectrum analysis respectively, and the results showed that the diatomite was successfully coated with CoNoP and Fe (carbony iron). The complex permittivity and permeability of composites filled with the bio-absorbent and paraffin was measured in frequency range of 2–18 GHz, and then the microwave reflection loss (RL) and the shielding effectiveness (SE) were calculated. The results showed that the permittivity and the permeability were both enlarged as Fe films were coated onto the CoNiP-coated diatomite, which was attributed to the excellent electromagnetic property of carbonyl irons. The composites made with the Fe-CoNiP diatomite had a better absorbing property (minimum RL −11.0 dB) as well as the shielding property (maximum SE 5.6 dB) at thickness 2 mm. It indicated the absorption property was mainly due to the attenuation on the microwave, and the Fe-CoNiP diatomite could be an effective absorbent with low-density

Microwave absorption property of the diatomite coated by Fe-CoNiP films

Energy Technology Data Exchange (ETDEWEB)

Yan, Zhenqiang; Cai, Jun; Xu, Yonggang, E-mail: xuyonggang221@163.com; Zhang, Deyuan

2015-08-15

Highlights: • The bio-absorbent coated Fe-CoNiP was fabricated by electroless and CVD. • The EM parameters were enlarged as Fe coated on the diatomite. • The coating CIPs play a key role in the enhancement mechanism. • The Fe-CoNiP diatomite had a better absorbing and shielding properties. - Abstract: A bio-absorbent of Fe-CoNiP coated on the diatomite was fabricated by way of electroless plating of CoNiP and subsequent chemical vapor deposition of Fe. The surface morphology and composition of the above-mentioned diatomite particles at different stage were characterized with the scanning electron microscopy and the energy spectrum analysis respectively, and the results showed that the diatomite was successfully coated with CoNoP and Fe (carbony iron). The complex permittivity and permeability of composites filled with the bio-absorbent and paraffin was measured in frequency range of 2–18 GHz, and then the microwave reflection loss (RL) and the shielding effectiveness (SE) were calculated. The results showed that the permittivity and the permeability were both enlarged as Fe films were coated onto the CoNiP-coated diatomite, which was attributed to the excellent electromagnetic property of carbonyl irons. The composites made with the Fe-CoNiP diatomite had a better absorbing property (minimum RL −11.0 dB) as well as the shielding property (maximum SE 5.6 dB) at thickness 2 mm. It indicated the absorption property was mainly due to the attenuation on the microwave, and the Fe-CoNiP diatomite could be an effective absorbent with low-density.

Solubilization of paraffinic deposits for microemulsions

Energy Technology Data Exchange (ETDEWEB)

Gomes, Erika A.S.; Soares, Ranieri G.F.; Nascimento, Roseane E.S.; Dantas Neto, Afonso A.; Barros Neto, Eduardo L. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2008-07-01

The oil company has been intensifying its efforts to find more efficient solutions for the problems related to the paraffin in wells and transport lines. When applied in the flow lines, the solvents dissolve the paraffin and they must be used hot, since the temperature increases the solubility of the wax and, consequently, its removal rate. The microemulsions appear as an alternative capable of acting in the solubilization and in the inhibition of the formation of deposits due to its great interfacial area, low superficial tension and high capacity of solubilization. They present some advantages in relation to the methods of use of chemical products due to its flexibility of composition in which they can be used, presenting low toxicity and inflammability, without any loss of its capacity of solubilization. The use of oil-in-water microemulsion aims to solubilized paraffin in the disperse phase, where one can find the apolar part of the molecule of the surfactant and the also apolar chain of paraffin, occurring, therefore the 'encapsulation' of the crystal, prohibiting the growth of the chain due to the affinity of paraffin and oil. In this in case, it is possible to transport the inserted paraffin in direct micelles, reducing the precipitation and optimizing the transport. (author)

The TiO2 Refraction Film for CsI Scintillator

OpenAIRE

C. C. Chen; C. W. Hun; C. J. Wang; C. Y. Chen; J. S. Lin; K. J. Huang

2015-01-01

Cesium iodide (CsI) melt was injected into anodic aluminum oxide (AAO) template and was solidified to CsI column. The controllable AAO channel size (10~500 nm) can makes CsI column size from 10 to 500 nm in diameter. In order to have a shorter light irradiate from each singe CsI column top to bottom the AAO template was coated a TiO2 nano-film. The TiO2 film acts a refraction film and makes X-ray has a shorter irradiation path in the CsI crystal making a stronger the photo-electron signal. Wh...

Pulsed vapor source for use in ion sources for heavy-ion accelerators

International Nuclear Information System (INIS)

Shiloh, J.; Chupp, W.; Faltens, A.; Keefe, D.; Kim, C.; Rosenblum, S.; Tiefenback, M.

1980-01-01

A pulsed cesium vapor source for use in ion sources for high-current heavy-ion accelerators is described. The source employs a vacuum spark in Cs and its properties are measured with a hot-filament Cs detector

Silicon-substituted hydroxyapatite coating with Si content on the nanotube-formed Ti–Nb–Zr alloy using electron beam-physical vapor deposition

International Nuclear Information System (INIS)

Jeong, Yong-Hoon; Choe, Han-Cheol; Brantley, William A.

2013-01-01

The purpose of this study was to investigate the electrochemical characteristics of silicon-substituted hydroxyapatite coatings on the nanotube-formed Ti–35Nb–10Zr alloy. The silicon-substituted hydroxyapatite (Si–HA) coatings on the nanotube structure were deposited by electron beam-physical vapor deposition and anodization methods, and biodegradation properties were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy measurement. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The Si–HA layers were deposited with rough features having highly ordered nanotube structures on the titanium alloy substrate. The thickness of the Si–HA coating was less than that of the HA coating. The XRD results confirmed that the Si–HA coating on the nanotube structure consisted of TiO 2 anatase, TiO 2 rutile, hydroxyapatite, and calcium phosphate silicate. The Si–HA coating surface exhibited lower I corr than the HA coating, and the polarization resistance was increased by substitution of silicon in hydroxyapatite. - Highlights: • Silicon substituted hydroxyapatite (Si–HA) was coated on nanotubular titanium alloy. • The Si–HA coating thickness was less than single hydroxyapatite (HA) coating. • Si–HA coatings consisted of TiO 2 , HA, and Ca 5 (PO 4 ) 2 SiO 4 . • Polarization resistance of the coating was increased by Si substitution in HA

High performance LiNi0.5Mn1.5O4 cathode by Al-coating and Al3+-doping through a physical vapor deposition method

International Nuclear Information System (INIS)

Sun, Peng; Ma, Ying; Zhai, Tianyou; Li, Huiqiao

2016-01-01

Highlights: • Metal Al was used as an electrical conductive coating material for LiNi 0.5 Mn 1.5 O 4 . • The uniform surface coating layer of metal Al was successfully achieved with adjusted thickness through a physical vapor deposition technology. • Al 3+ -doped LiNi 0.5 Mn 1.5 O 4 can be easily obtained by further directly annealing of Al-coated LiNi 0.5 Mn 1.5 O 4 in air. • The conductive Al-coating layer can greatly improve the rate performance and cycle stability of LiNi 0.5 Mn 1.5 O 4 . - Abstract: In this work, spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) hollow microspheres are synthesized by an impregnation method using microsphere MnO 2 as both the precursor and template. To enhance the electrical conductivity of LNMO, metal Al was employed for the first time as a coating material for LNMO. Though an Electron-beam Vapor Deposition approach, the surface of LNMO can be easily coated by a tight layer of Al nanoparticles with adjusted thickness. Further annealing the Al-coated sample at 800 °C in air, the Al 3+ -doped LNMO can be obtained. The effects of Al-coating and Al 3+ -doping on the sample morphology and structure are investigated by SEM, TEM, XRD and FT-IR. The electrochemical properties of Al-coated LNMO and Al 3+ -doped LNMO are measured with comparison of bare LNMO by charge/discharge tests and electrochemical impedance spectroscopy (EIS). The results show that both Al-coating and Al 3+ -doping can greatly enhance the cycle performance and rate capability of LNMO. Especially for Al-coated LNMO, it shows the lowest battery impedance due to the existence of conductive Al coating layer, thus delivers the best rate performance among the three. The physical coating procedure used in this work may provide a new facile modification approach for other cathode materials.

Liposomes coated with thiolated chitosan enhance oral peptide delivery to rats.

Science.gov (United States)

Gradauer, K; Barthelmes, J; Vonach, C; Almer, G; Mangge, H; Teubl, B; Roblegg, E; Dünnhaupt, S; Fröhlich, E; Bernkop-Schnürch, A; Prassl, R

2013-12-28

The aim of the present study was the in vivo evaluation of thiomer-coated liposomes for an oral application of peptides. For this purpose, salmon calcitonin was chosen as a model drug and encapsulated within liposomes. Subsequently, the drug loaded liposomes were coated with either chitosan-thioglycolic acid (CS-TGA) or an S-protected version of the same polymer (CS-TGA-MNA), leading to an increase in the particle size of about 500 nm and an increase in the zeta potential from approximately -40 mV to a maximum value of about +44 mV, depending on the polymer. Coated liposomes were demonstrated to effectively penetrate the intestinal mucus layer where they came in close contact with the underlying epithelium. To investigate the permeation enhancing properties of the coated liposomes ex vivo, we monitored the transport of fluoresceinisothiocyanate-labeled salmon calcitonin (FITC-sCT) through rat small intestine. Liposomes coated with CS-TGA-MNA showed the highest effect, leading to a 3.8-fold increase in the uptake of FITC-sCT versus the buffer control. In vivo evaluation of the different formulations was carried out by the oral application of 40 μg of sCT per rat, either encapsulated within uncoated liposomes, CS-TGA-coated liposomes or CS-TGA-MNA-coated liposomes, or given as a solution serving as negative control. The blood calcium level was monitored over a time period of 24h. The highest reduction in the blood calcium level, to a minimum of 65% of the initial value after 6h, was achieved for CS-TGA-MNA-coated liposomes. Comparing the areas above curves (AAC) of the blood calcium levels, CS-TGA-MNA-coated liposomes led to an 8.2-fold increase compared to the free sCT solution if applied orally in the same concentration. According to these results, liposomes coated with S-protected thiomers have demonstrated to be highly valuable carriers for enhancing the oral bioavailability of salmon calcitonin. © 2013. Published by Elsevier B.V. All rights reserved.

Binary liquid-liquid equilibria of aniline-paraffin and furfural-paraffin systems

Energy Technology Data Exchange (ETDEWEB)

Sen, S.C.; Maity, S.; Ganguli, K.; Ray, P. (Calcutta Univ., (India))

1991-12-01

Liquid-liquid-equilibria (L-L-E) of hydrocarbon containing systems are of considerable commercial importance to refineries. But prediction of L-L-E of such systems is extremely difficult owing to the complex nature of the petroleum fluids. For treating such complex mixtures, a continuous component method is appropriate and for representing such liquids, a group contribution model like the UNIFAC is extremely convenient. It is, however, necessary to determine the appropriate group interaction parameters, and also to test the applicability of the UNIFAC method to these cases. Binary liquid-liquid-equilibria data for several aniline-paraffin and furfural-paraffin systems have been taken. These data along with data for other aniline-hydrocarbon and furfural-hydrocarbon systems from literature have been correlated using the UNIFAC model. The UNIFAC group interaction parameters have been found to have a linear temperature dependence. The CH{sub 2} groups in cyclo and non-cyclo paraffins require different interaction parameters. It was also found that a scaling of the combinatorial term is necessary for higher molecular weight hydrocarbons. 13 refs., 12 figs., 5 tabs.

Corrosion-resistant coating development

Energy Technology Data Exchange (ETDEWEB)

Stinton, D.P.; Kupp, D.M.; Martin, R.L. [Oak Ridge National Lab., TN (United States)

1997-12-01

SiC-based heat exchangers have been identified as the prime candidate material for use as heat exchangers in advanced combined cycle power plants. Unfortunately, hot corrosion of the SiC-based materials created by alkali metal salts present in the combustion gases dictates the need for corrosion-resistant coatings. The well-documented corrosion resistance of CS-50 combined with its low (and tailorable) coefficient of thermal expansion and low modulus makes CS-50 an ideal candidate for this application. Coatings produced by gelcasting and traditional particulate processing have been evaluated.

Thermodynamics and Kinetics of Silicate Vaporization

Science.gov (United States)

Jacobson, Nathan S.; Costa, Gustavo C. C.

2015-01-01

Silicates are a common class of materials that are often exposed to high temperatures. The behavior of these materials needs to be understood for applications as high temperature coatings in material science as well as the constituents of lava for geological considerations. The vaporization behavior of these materials is an important aspect of their high temperature behavior and it also provides fundamental thermodynamic data. The application of Knudsen effusion mass spectrometry (KEMS) to silicates is discussed. There are several special considerations for silicates. The first is selection of an appropriate cell material, which is either nearly inert or has well-understood interactions with the silicate. The second consideration is proper measurement of the low vapor pressures. This can be circumvented by using a reducing agent to boost the vapor pressure without changing the solid composition or by working at very high temperatures. The third consideration deals with kinetic barriers to vaporization. The measurement of these barriers, as encompassed in a vaporization coefficient, is discussed. Current measured data of rare earth silicates for high temperature coating applications are discussed. In addition, data on magnesium-iron-silicates (olivine) are presented and discussed.

Residual stress in thick low-pressure chemical-vapor deposited polycrystalline SiC coatings on Si substrates

Science.gov (United States)

Choi, D.; Shinavski, R. J.; Steffier, W. S.; Spearing, S. M.

2005-04-01

Residual stress in thick coatings of polycrystalline chemical-vapor deposited SiC on Si substrates is a key variable that must be controlled if SiC is to be used in microelectromechanical systems. Studies have been conducted to characterize the residual stress level as a function of deposition temperature, Si wafer and SiC coating thickness, and the ratios of methyltrichlorosilane to hydrogen and hydrogen chloride. Wafer curvature was used to monitor residual stress in combination with a laminated plate analysis. Compressive intrinsic (growth) stresses were measured with magnitudes in the range of 200-300MPa; however, these can be balanced with the tensile stress due to the thermal-expansion mismatch to leave near-zero stress at room temperature. The magnitude of the compressive intrinsic stress is consistent with previously reported values of surface stress in combination with the competition between grain-boundary energy and elastic strain energy.

Sr-doped nanowire modification of Ca-Si-based coatings for improved osteogenic activities and reduced inflammatory reactions

Science.gov (United States)

Li, Kai; Hu, Dandan; Xie, Youtao; Huang, Liping; Zheng, Xuebin

2018-02-01

Biomedical coatings for orthopedic implants should facilitate osseointegration and mitigate implant-induced inflammatory reactions. In our study, Ca-Si coatings with Sr-containing nanowire-like structures (NW-Sr-CS) were achieved via hydrothermal treatment. In order to identify the effect of nanowire-like topography and Sr dopant on the biological properties of Ca-Si-based coatings, the original Ca-Si coating, Ca-Si coatings modified with nanoplate (NP-CS) and similar nanowire-like structure (NW-CS) were fabricated as the control. Surface morphology, phase composition, surface area, zeta potential and ion release of these coatings were characterized. The in vitro osteogenic activities and immunomodulatory properties were evaluated with bone marrow stromal cells (BMSCs) and RAW 264.7 cells, a mouse macrophage cell line. Compared with the CS and NP-CS coatings, the NW-CS coating possessed a larger surface area and pore volume, beneficial protein adsorption, up-regulated the expression levels of integrin β1, Vinculin and focal adhesion kinase and promoted cell spreading. Furthermore, the NW-CS coating significantly enhanced the osteogenic differentiation and mineralization as indicated by the up-regulation of ALP activity, mineralized nodule formation and osteoblastogenesis-related gene expression. With the introduction of Sr, the NW-Sr-CS coatings exerted a greater effect on the BMSC proliferation rate, calcium sensitive receptor gene expression as well as PKC and ERK1/2 phosphorylation. In addition, the Sr-doped coatings significantly up-regulated the ratio of OPG/RANKL in the BMSCs. The NW-Sr-CS coatings could modulate the polarization of macrophages towards the wound-healing M2 phenotype, reduce the mRNA expression levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) and enhance anti-inflammatory cytokines (IL-1ra, IL-10). The Sr-doped nanowire modification may be a valuable approach to enhance osteogenic activities and reduce inflammatory reactions.

The Tribological Behaviors of Three Films Coated on Biomedical Titanium Alloy by Chemical Vapor Deposition

Science.gov (United States)

Wang, Song; Liao, Zhenhua; Liu, Yuhong; Liu, Weiqiang

2015-11-01

Three thin films (DLC, a-C, and TiN) were performed on Ti6Al4V by chemical vapor deposition. Carbon ion implantation was pretreated for DLC and a-C films while Ti transition layer was pretreated for TiN film to strengthen the bonding strength. X-ray diffraction, Raman measurement, nano-hardness and nano-scratch tester, and cross-section etching by FIB method were used to analyze film characteristics. Tribological behaviors of these coatings were studied by articulation with both ZrO2 and UHMWPE balls using ball-on-disk sliding. The thickness values reached ~0.46, ~0.33, and ~1.67 μm for DLC, a-C, and TiN film, respectively. Nano-hardness of the coatings compared with that of untreated and bonding strength (critical load in nano-scratch test) values of composite coatings compared with that of monolayer film all increased significantly, respectively. Under destructive test (ZrO2 ball conterface) in bovine serum lubrication, TiN coating revealed the best wear resistance while DLC showed the worst. Film failure was mainly attributed to the plowing by hard ZrO2 ball characterized by abrasive and adhesive wear. Under normal test (UHMWPE ball conterface), all coatings showed significant improvement in wear resistance both in dry sliding and bovine serum lubrication. Both DLC and a-C films showed less surface damage than TiN film due to the self-lubricating phenomenon in dry sliding. TiN film showed the largest friction coefficient both in destructive and normal tests, devoting to the big TiN grains thus leading to much rougher surface and then a higher value. The self-lubricating film formed on DLC and a-C coating could also decrease their friction coefficients. The results indicated that three coatings revealed different wear mechanisms, and thick DLC or a-C film was more promising in application in lower stress conditions such as artificial cervical disk.

A solid-state nuclear magnetic resonance study of post-plasma reactions in organosilicone microwave plasma-enhanced chemical vapor deposition (PECVD) coatings.

Science.gov (United States)

Hall, Colin J; Ponnusamy, Thirunavukkarasu; Murphy, Peter J; Lindberg, Mats; Antzutkin, Oleg N; Griesser, Hans J

2014-06-11

Plasma-polymerized organosilicone coatings can be used to impart abrasion resistance and barrier properties to plastic substrates such as polycarbonate. Coating rates suitable for industrial-scale deposition, up to 100 nm/s, can be achieved through the use of microwave plasma-enhanced chemical vapor deposition (PECVD), with optimal process vapors such as tetramethyldisiloxane (TMDSO) and oxygen. However, it has been found that under certain deposition conditions, such coatings are subject to post-plasma changes; crazing or cracking can occur anytime from days to months after deposition. To understand the cause of the crazing and its dependence on processing plasma parameters, the effects of post-plasma reactions on the chemical bonding structure of coatings deposited with varying TMDSO-to-O2 ratios was studied with (29)Si and (13)C solid-state magic angle spinning nuclear magnetic resonance (MAS NMR) using both single-pulse and cross-polarization techniques. The coatings showed complex chemical compositions significantly altered from the parent monomer. (29)Si MAS NMR spectra revealed four main groups of resonance lines, which correspond to four siloxane moieties (i.e., mono (M), di (D), tri (T), and quaternary (Q)) and how they are bound to oxygen. Quantitative measurements showed that the ratio of TMDSO to oxygen could shift the chemical structure of the coating from 39% to 55% in Q-type bonds and from 28% to 16% for D-type bonds. Post-plasma reactions were found to produce changes in relative intensities of (29)Si resonance lines. The NMR data were complemented by Fourier transform infrared (FTIR) spectroscopy. Together, these techniques have shown that the bonding environment of Si is drastically altered by varying the TMDSO-to-O2 ratio during PECVD, and that post-plasma reactions increase the cross-link density of the silicon-oxygen network. It appears that Si-H and Si-OH chemical groups are the most susceptible to post-plasma reactions. Coatings produced at a

Bio-paraffins: alternative products to petroleum paraffins; Bioparafinas: produtos alternativos as parafinas de petroleo

Energy Technology Data Exchange (ETDEWEB)

Lima, Anie Daniela Medeiros [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Hidrorrefino e Processos Especiais; Oliveira, Claudia Cristina Cardoso Calvano de; Carvalho, Ivone de Freitas; Silva, Danilo do Carmo Santos; Cruz, Valeria Senra da Silva [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Lubrificantes e Produtos Especiais]. E-mails: anie.lima, claudiacristina, ivone, danilosilva, vsenra@petrobras.com.br

2007-04-15

Market trends and social and environmental issues encouraged the vegetal wax presence in the world-wide paraffin market. This work presents the most commercialized vegetal waxes, soy and pal, comparing their physicochemical characteristics and their applicability with the paraffins obtained from petroleum. It also presents a characterization of the carnauba wax, produced exclusively in Brazil and a comparison with paraffins from petroleum. The carnauba wax is an alternative product, with good applicability as a substitute for waxes from petroleum or a petroleum/vegetal mixture. The characteristics of palm and soy waxes show the possible application in candles, cosmetics, foods and others industries. Brazil, having a great agricultural potential, represents a source of vegetal wax that could be use to meet the market demands. (author)

Coating Performance in Duluth Superior Harbor. Part 2

Science.gov (United States)

2012-10-01

tures in fresh water , and nine coatings were evaluated for corrosion protection of CS coupons and I-beams around DSH after 46 and 35 months...following coatings were selected for this evaluation: 1 Aquapure HR* 2 Chevron Phillips 1ZSMV 3 Standard epoxy 4 HumidurML* 5 Wasser MC-zinc/MC-tar* 6...one option for protection of extensive structures in fresh water , and nine coatings were evaluated for corrosion protection of CS coupons and I-beams

Deposition of titanium coating on SiC fiber by chemical vapor deposition with Ti-I{sub 2} system

Energy Technology Data Exchange (ETDEWEB)

Luo, Xian, E-mail: luo_shenfan@hotmail.com; Wu, Shuai; Yang, Yan-qing; Jin, Na; Liu, Shuai; Huang, Bin

2017-06-01

Highlights: • The transformation paths of (Ti + I{sub 2}) powder to Ti coating is: Ti + I{sub 2} → (TiI{sub 2}, TiI{sub 3}) → Ti. • Uniform coating was obtained on SiC fiber, but it contained Si and C elements. • Deposition rate of the coating increased with the increase of temperature. • Deposition thickness increased with time and achieved the maximum at 90 min. - Abstract: Titanium coating was prepared on SiC fiber using titanium-iodine (Ti-I{sub 2}) mixture by hot-wall chemical vapor deposition. Thermodynamic analysis and experimental observation were carried out in this work. The thermodynamic analysis of the reactions in the Ti-I{sub 2} system indicates that Ti and I{sub 2} raw powder materials transform to titanium coating as follows: Ti + I{sub 2} → (TiI{sub 2}, TiI{sub 3}), and (TiI{sub 2}, TiI{sub 3}) → Ti. In theory, the conversions of TiI{sub 3} and TiI{sub 2} reach the maximum when Ti:I{sub 2} is 1:1.5, while in actual experiment that reached the maximum when Ti:I{sub 2} was 1:2, as there existed the waste of I{sub 2} due to sublimation. Typical deposited coating is relatively flat and uniform. However, as SiC is prone to react with Ti at high temperatures, the obtained coating contained some Si and C elements except for Ti. So the coating was not a pure Ti coating but contained some carbides and silicides. Deposition rate of the coating increased with the increase of temperature. The deposited thickness increased with the increase of heat preservation time, and achieved the maximum thickness at 90 min.

Effects of graphene plates' adoption on the microstructure, mechanical properties, and in vivo biocompatibility of calcium silicate coating.

Science.gov (United States)

Xie, Youtao; Li, Hongqin; Ding, Chuanxian; Zheng, Xuebin; Li, Kai

2015-01-01

Calcium silicate (CS) ceramic is a good coating candidate for biomedical implants to improve biocompatibility and accelerate early osseointegration. However, the poor fracture toughness and wear resistance of this ceramic material restricts the long-term performance of implants. In this study, graphene plates (GPs) were used as reinforcement to improve the mechanical properties of CS coating. Composite coating containing 1.5 weight % GPs was prepared by vacuum plasma spraying technology. The good survival of the GPs in the composite coating was demonstrated by Raman analysis, although the defects of the GPs were increased after plasma spraying. Effects of the GPs' adoption on the microstructure of the coating were studied by scanning electron microscopy and transmission electron microscopy. Results showed that the GPs were homogenously distributed in the CS grains interface or enwrapped on the particles, and exhibited good wetting behavior with the CS matrix. The wear properties of the composite coating were obviously enhanced by the reinforcement of GPs. The reinforcement mechanism was attributed to the enhanced micro-hardness and interfacial bonding of the particles in the coating. In vivo experiments demonstrated that the composite coating possessed similarly good biocompatibility compared to pure CS coating. The bone-implant contact ratio reached 84.3%±7.4% for GPs/CS coating and 79.6%±9.4% for CS coating after 3 months' implantation.

Effects of graphene plates’ adoption on the microstructure, mechanical properties, and in vivo biocompatibility of calcium silicate coating

Science.gov (United States)

Xie, Youtao; Li, Hongqin; Ding, Chuanxian; Zheng, Xuebin; Li, Kai

2015-01-01

Calcium silicate (CS) ceramic is a good coating candidate for biomedical implants to improve biocompatibility and accelerate early osseointegration. However, the poor fracture toughness and wear resistance of this ceramic material restricts the long-term performance of implants. In this study, graphene plates (GPs) were used as reinforcement to improve the mechanical properties of CS coating. Composite coating containing 1.5 weight % GPs was prepared by vacuum plasma spraying technology. The good survival of the GPs in the composite coating was demonstrated by Raman analysis, although the defects of the GPs were increased after plasma spraying. Effects of the GPs’ adoption on the microstructure of the coating were studied by scanning electron microscopy and transmission electron microscopy. Results showed that the GPs were homogenously distributed in the CS grains interface or enwrapped on the particles, and exhibited good wetting behavior with the CS matrix. The wear properties of the composite coating were obviously enhanced by the reinforcement of GPs. The reinforcement mechanism was attributed to the enhanced micro-hardness and interfacial bonding of the particles in the coating. In vivo experiments demonstrated that the composite coating possessed similarly good biocompatibility compared to pure CS coating. The bone-implant contact ratio reached 84.3%±7.4% for GPs/CS coating and 79.6%±9.4% for CS coating after 3 months’ implantation. PMID:26089662

Silicon-substituted hydroxyapatite coating with Si content on the nanotube-formed Ti–Nb–Zr alloy using electron beam-physical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Jeong, Yong-Hoon [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH (United States); Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Brantley, William A. [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH (United States)

2013-11-01

The purpose of this study was to investigate the electrochemical characteristics of silicon-substituted hydroxyapatite coatings on the nanotube-formed Ti–35Nb–10Zr alloy. The silicon-substituted hydroxyapatite (Si–HA) coatings on the nanotube structure were deposited by electron beam-physical vapor deposition and anodization methods, and biodegradation properties were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy measurement. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The Si–HA layers were deposited with rough features having highly ordered nanotube structures on the titanium alloy substrate. The thickness of the Si–HA coating was less than that of the HA coating. The XRD results confirmed that the Si–HA coating on the nanotube structure consisted of TiO{sub 2} anatase, TiO{sub 2} rutile, hydroxyapatite, and calcium phosphate silicate. The Si–HA coating surface exhibited lower I{sub corr} than the HA coating, and the polarization resistance was increased by substitution of silicon in hydroxyapatite. - Highlights: • Silicon substituted hydroxyapatite (Si–HA) was coated on nanotubular titanium alloy. • The Si–HA coating thickness was less than single hydroxyapatite (HA) coating. • Si–HA coatings consisted of TiO{sub 2}, HA, and Ca{sub 5}(PO{sub 4}){sub 2}SiO{sub 4}. • Polarization resistance of the coating was increased by Si substitution in HA.

Osteogenetic property of a biodegradable three-dimensional macroporous hydrogel coating on titanium implants fabricated via EPD

International Nuclear Information System (INIS)

Ma, Kena; Cai, Xinjie; Zhou, Yi; Jiang, Tao; Wang, Yining; Zhang, Zhen

2014-01-01

The potential for a successful integration of implants with surrounding tissue may be jeopardized in a number of compromised conditions. Biochemical surface modification is one of the choices to extend the spectrum of indications. We have previously successfully fabricated chitosan–gelatin (CS/G) coatings on a titanium surface via electrophoretic deposition, which may be promising candidates for further loading of functional agents. In this study, we have identified the microstructure, physicochemical properties and biological performance of CS/G coatings in vitro and in vivo. The in vitro degradation test indicated that CS/G coatings in the presence of lysozyme showed a significant weight loss after 28 days. The results of the cell culture exhibited that CS/G coatings could sustain MC3T3-E1 cell attachment, proliferation and migration. In vivo osteogenetic behavior evaluated by Micro-CT and histomorphometrical analysis revealed significant new bone formation around CS/G implants at 8 and 12 weeks, compared to sandblasted/acid-etched implants. Moreover, histological evaluation suggested the majority of CS/G coatings were degraded at 12 weeks. Therefore, we have concluded that the three-dimensional porous structure of scaffold-like CS/G coatings may facilitate osteogenesis and that such coatings can be biodegraded in the early bone healing process. (paper)

Surface modification of reverse osmosis desalination membranes by thin-film coatings deposited by initiated chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Ozaydin-Ince, Gozde, E-mail: gozdeince@sabanciuniv.edu [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Matin, Asif, E-mail: amatin@mit.edu [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Khan, Zafarullah, E-mail: zukhan@mit.edu [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Zaidi, S.M. Javaid, E-mail: zaidismj@kfupm.edu.sa [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Gleason, Karen K., E-mail: kkgleasn@mit.edu [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

2013-07-31

Thin-film polymeric reverse osmosis membranes, due to their high permeation rates and good salt rejection capabilities, are widely used for seawater desalination. However, these membranes are prone to biofouling, which affects their performance and efficiency. In this work, we report a method to modify the membrane surface without damaging the active layer or significantly affecting the performance of the membrane. Amphiphilic copolymer films of hydrophilic hydroxyethylmethacrylate and hydrophobic perfluorodecylacrylate (PFA) were synthesized and deposited on commercial RO membranes using an initiated chemical vapor deposition technique which is a polymer deposition technique that involves free-radical polymerization initiated by gas-phase radicals. Relevant surface characteristics such as hydrophilicity and roughness could be systematically controlled by varying the polymer chemistry. Increasing the hydrophobic PFA content in the films leads to an increase in the surface roughness and hydrophobicity. Furthermore, the surface morphology studies performed using the atomic force microscopy show that as the thickness of the coating increases average surface roughness increases. Using this knowledge, the coating thickness and chemistry were optimized to achieve high permeate flux and to reduce cell attachment. Results of the static bacterial adhesion tests show that the attachment of bacterial cells is significantly reduced on the coated membranes. - Highlights: • Thin films are deposited on reverse osmosis membranes. • Amphiphilic thin films are resistant to protein attachment. • The permeation performance of the membranes is not affected by the coating. • The thin film coatings delayed the biofouling.

Sealing-free fast-response paraffin/nanoporous gold hybrid actuator

Science.gov (United States)

Ye, Xing-Long; Jin, Hai-Jun

2017-09-01

Paraffin-based actuators can deliver large actuation strokes and high actuation stress, but often suffer from a low response rate and leaking problems. Here, we report a new paraffin/metal hybrid actuator, which was fabricated by infiltrating nanoporous gold with paraffin. It exhibits a fast actuation rate owing to the high thermal conductivity of the inter-connected metal phase, and requires no external sealing because liquid paraffin can be well confined in nanoscale channels, due to the large capillarity. We found that in this hybrid actuator, the stress generated by actuation is negligibly small when the characteristic size of the nanoporous gold (L) is above ˜70 nm, and increases dramatically with a decreasing size when L paraffin wax—the paraffin in smaller pores can sustain larger tensile stress, and thus the contraction of paraffin during cooling can be translated into larger compression stress and strain energy in a metal framework, leading to a larger actuation stress and energy. We also demonstrate that complex actuation motions can be achieved by incorporating hierarchical-structured nanoporous metal with paraffin.

Vapor deposition of tantalum and tantalum compounds

International Nuclear Information System (INIS)

Trkula, M.

1996-01-01

Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition

Effects of heat treatment on the microstructure of amorphous boron carbide coating deposited on graphite substrates by chemical vapor deposition

International Nuclear Information System (INIS)

Li Siwei; Zeng Bin; Feng Zude; Liu Yongsheng; Yang Wenbin; Cheng Laifei; Zhang Litong

2010-01-01

A two-layer boron carbide coating is deposited on a graphite substrate by chemical vapor deposition from a CH 4 /BCl 3 /H 2 precursor mixture at a low temperature of 950 o C and a reduced pressure of 10 KPa. Coated substrates are annealed at 1600 o C, 1700 o C, 1800 o C, 1900 o C and 2000 o C in high purity argon for 2 h, respectively. Structural evolution of the coatings is explored by electron microscopy and spectroscopy. Results demonstrate that the as-deposited coating is composed of pyrolytic carbon and amorphous boron carbide. A composition gradient of B and C is induced in each deposition. After annealing, B 4 C crystallites precipitate out of the amorphous boron carbide and grow to several hundreds nanometers by receiving B and C from boron-doped pyrolytic carbon. Energy-dispersive spectroscopy proves that the crystallization is controlled by element diffusion activated by high temperature annealing, after that a larger concentration gradient of B and C is induced in the coating. Quantified Raman spectrum identifies a graphitization enhancement of pyrolytic carbon. Transmission electron microscopy exhibits an epitaxial growth of B 4 C at layer/layer interface of the annealed coatings. Mechanism concerning the structural evolution on the basis of the experimental results is proposed.

Tribological behavior at elevated temperature of multilayer TiCN/TiC/TiN hard coatings produced by chemical vapor deposition

International Nuclear Information System (INIS)

Bao Mingdong; Xu Xuebo; Zhang Haijun; Liu Xiaoping; Tian Linhai; Zeng Zhaoxin; Song Yubin

2011-01-01

Multilayer hard coatings of TiCN/TiC/TiN on high speed steel substrates were deposited using a chemical vapor deposition system. Evaluations of microstructure, wear morphology of coatings were characterized by scanning electron microscopy, and optical microscopy. Friction coefficient and wear rates of coatings were investigated using ball-on-disk tester sliding against a WC ball at a constant load of 20 N. Tribological behavior of the coatings at room and elevated temperature were discussed. Different changing tendency of friction coefficient were observed from ball-on-disc experiments. Results showed that the friction coefficient of coatings increased gradually to a highest value, then to a relatively constant value at room temperature dry sliding wear. The friction coefficient exhibited a reverse variation tendency at temperature of 550 °C. It got a higher value at the first sliding friction cycles. Then the value of friction coefficient decreased, suffered irregular oscillations and kept a relatively lower value with increasing sliding time. Reasons of the variation of friction coefficient with sliding time and wear mechanism were analyzed and discussed at room and elevated temperatures, respectively.

Evaluation of different tissue de-paraffinization procedures for infrared spectral imaging.

Science.gov (United States)

Nallala, Jayakrupakar; Lloyd, Gavin Rhys; Stone, Nicholas

2015-04-07

In infrared spectral histopathology, paraffin embedded tissues are often de-paraffinized using chemical agents such as xylene and hexane. These chemicals are known to be toxic and the routine de-waxing procedure is time consuming. A comparative study was carried out to identify alternate de-paraffinization methods by using paraffin oil and electronic de-paraffinization (using a mathematical computer algorithm) and their effectiveness was compared to xylene and hexane. Sixteen adjacent tissue sections obtained from a single block of a normal colon tissue were de-paraffinized using xylene, hexane and paraffin oil (+ hexane wash) at five different time points each for comparison. One section was reserved unprocessed for electronic de-paraffinization based on a modified extended multiplicative signal correction (EMSC). IR imaging was carried out on these tissue sections. Coefficients based on the fit of a pure paraffin model to the IR images were then calculated to estimate the amount of paraffin remaining after processing. Results indicate that on average xylene removes more paraffin in comparison to hexane and paraffin oil although the differences were small. This makes paraffin oil, followed by a hexane wash, an interesting and less toxic alternative method of de-paraffinization. However, none of the chemical methods removed paraffin completely from the tissues at any given time point. Moreover, paraffin was removed more easily from the glandular regions than the connective tissue regions indicating a form of differential paraffin retention based on the histology. In such cases, the use of electronic de-paraffinization to neutralize such variances across different tissue regions might be considered. Moreover it is faster, reduces scatter artefacts by index matching and enables samples to be easily stored for further analysis if required.

Electrophoretic deposition of graphene oxide reinforced chitosan-hydroxyapatite nanocomposite coatings on Ti substrate.

Science.gov (United States)

Shi, Y Y; Li, M; Liu, Q; Jia, Z J; Xu, X C; Cheng, Y; Zheng, Y F

2016-03-01

Electrophoretic deposition (EPD) is a facile and feasible technique to prepare functional nanocomposite coatings for application in orthopedic-related implants. In this work, a ternary graphene oxide-chitosan-hydroxyapatite (GO-CS-HA) composite coating on Ti substrate was successfully fabricated by EPD. Coating microstructure and morphologies were investigated by scanning electron microscopy, contact angle test, Raman spectroscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. It was found GO-CS surface were uniformly decorated by HA nanoparticles. The potentiodynamic polarization test in simulated body fluid indicated that the GO-CS-HA coatings could provide effective protection of Ti substrate from corrosion. This ternary composite coating also exhibited good biocompatibility during incubation with MG63 cells. In addition, the nanocomposite coatings could decrease the attachment of Staphylococcus aureus.

Study of ion plating parameters, coating structure, and corrosion protection for aluminum coatings on uranium

International Nuclear Information System (INIS)

Egert, C.M.; Scott, D.G.

1987-01-01

A study of ion-plating parameters (primarily deposition rate and substrate bias voltage), coating structure, and the corrosion protection provided by aluminum coatings on uranium is presented. Ion plating at low temperatures yields a variety of aluminum coating structures on uranium. For example, aluminum coatings produced at high deposition rates and low substrate bias voltages are columnar with voids between columns, as expected for high-rate vapor deposition at low temperatures. On the other hand, low deposition rate and high bias voltage produce a modified coating with a dense, noncolumnar structure. These results are not in agreement with other studies that have found no relationship between deposition rate and coating structure in ion plating. This discrepancy is probably due to the high deposition rates used in these studies. An accelerated, water vapor corrosion test indicates that the columnar aluminum coatings provide some corrosion protection despite their porous nature; however, the dense noncolumnar coatings provide significantly greater protection. These results indicate that ion-plated aluminum coatings produced at low deposition rates and high substrate bias voltages creates dense coating structures that are most effective in protecting uranium from corrosion

7 CFR 58.427 - Paraffin tanks.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Paraffin tanks. 58.427 Section 58.427 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....427 Paraffin tanks. The metal tank should be adequate in size, have wood rather than metal racks to...

P-T and T-x projections of phase diagram of CsF-ZrF4 system

International Nuclear Information System (INIS)

Karasev, N.M.; Korenev, Yu.M.; Sidorov, L.N.

1980-01-01

The CsF-ZrF 4 system has been investigated by the Knudsen effusion method and mass-spectral analysis of vaporization products. A molecular composition of vapour was determined. CsF, Cs 2 F 2 , ZrF 4 , Cs 2 ZrF 6 , CsZrF 5 , CsZr 2 F 9 molecules were found in the saturated vapour of the system. Heats of phase transitions and partial pressures of the molecules detected were determined depending on the melt compositions. Dissociation enthalpies of complex molecules were calculated. P-T and T-x projections of the state diagram of the CsF-ZrF 4 system were constructed

Hyperfine relaxation of an optically pumped cesium vapor

International Nuclear Information System (INIS)

Tornos, J.; Amare, J.C.

1986-01-01

The relaxation of hyperfine orientation indirectly induced by optical pumping with a σ-polarized D 1 -light in a cesium vapor in the presence of Ar is experimentally studied. The detection technique ensures the absence of quadrupole relaxation contributions in the relaxation signals. The results from the dependences of the hyperfine relaxation rate on the temperature and argon pressure are: diffusion coefficient of Cs in Ar, D 0 = 0.101 +- 0.010 cm 2 s -1 at 0 0 C and 760 Torr; relaxation cross section by Cs-Ar collisions, σ/sub c/ = (104 +- 5) x 10 -23 cm 2 ; relaxation cross section by Cs-Cs (spin exchange) collisions, σ/sub e//sub x/ = (1.63 +- 0.13) x 10 -14 cm 2

Radiometric determination of uniformity of putting paraffin on textile threads

International Nuclear Information System (INIS)

Ridel', Z.; Kherrmann, Eh.; Shefer, I.; Tseiner, A.

1979-01-01

To improve processing of the natural and synthetic fiber threads on stocking-frames, they are treated by paraffin. Paraffin is applied in the amounts nearly equal to 0.1 -1.0 g for 10 4 m of the thread's length. To determine amount of paraffin on thread and to determine uniformity if its application, a radiometric method has been developed. As a radioactive label, didocilephosphate of rare earths was used. This compound has good solubility in hydrocarbons and does not change physical properties of paraffin in the investigated field of its application as well as its concentration. It is possible to add to paraffin this radioactive label or a non-active label with subsequent its activation. Amount of paraffin, applied on a thread is determined by means of measurement of activity of thread samples of different length. Information about uniformity of paraffin application on thread have been obtained by means of autoradiography. It has been found that paraffin in mainly applied on the thread's bulges [ru

Modified paraffin wax for improvement of histological analysis efficiency.

Science.gov (United States)

Lim, Jin Ik; Lim, Kook-Jin; Choi, Jin-Young; Lee, Yong-Keun

2010-08-01

Paraffin wax is usually used as an embedding medium for histological analysis of natural tissue. However, it is not easy to obtain enough numbers of satisfactory sectioned slices because of the difference in mechanical properties between the paraffin and embedded tissue. We describe a modified paraffin wax that can improve the histological analysis efficiency of natural tissue, composed of paraffin and ethylene vinyl acetate (EVA) resin (0, 3, 5, and 10 wt %). Softening temperature of the paraffin/EVA media was similar to that of paraffin (50-60 degrees C). The paraffin/EVA media dissolved completely in xylene after 30 min at 50 degrees C. Physical properties such as the amount of load under the same compressive displacement, elastic recovery, and crystal intensity increased with increased EVA content. EVA medium (5 wt %) was regarded as an optimal composition, based on the sectioning efficiency measured by the numbers of unimpaired sectioned slices, amount of load under the same compressive displacement, and elastic recovery test. Based on the staining test of sectioned slices embedded in a 5 wt % EVA medium by hematoxylin and eosin (H&E), Masson trichrome (MT), and other staining tests, it was concluded that the modified paraffin wax can improve the histological analysis efficiency with various natural tissues. (c) 2010 Wiley-Liss, Inc.

Influence of Liquid Paraffin, White Soft Paraffin and Initial Hydration ...

African Journals Online (AJOL)

hydrated white soft paraffin on the viscosity of a cream formulated with a corticosteroid. Methods: The formulations were prepared via homogenization with variable velocity in the range 3300 - 4000 rpm. Individual series of preparations contained the ...

Graphene-reinforced calcium silicate coatings for load-bearing implants.

Science.gov (United States)

Xie, Youtao; Li, Hongqing; Zhang, Chi; Gu, Xin; Zheng, Xuebin; Huang, Liping

2014-04-01

Owing to the superior mechanical properties and low coefficient of thermal expansion, graphene has been widely used in the reinforcement of ceramics. In the present study, various ratios of graphene (0.5 wt%, 1.5 wt% and 4 wt%) were reinforced into calcium silicate (CS) coatings for load-bearing implant surface modification. Surface characteristics of the graphene/calcium silicate (GC) composite coatings were characterized by scanning electron microscopy. Results show that the graphene plates (less than 4 wt% in the coatings) were embedded in the CS matrix homogeneously. The surfaces of the coatings showed a hierarchical hybrid nano-/microstructure, which is believed to be beneficial to the behaviors of the cell and early bone fixation of the implants. Wear resistance measured by a pin-on-disc model exhibited an obvious enhancement with the adoption of graphene plates. The weight losses of the GC coatings decreased with the increase of graphene content. However, too high graphene content (4 wt% or more) made the composite coatings porous and the wear resistance decreased dramatically. The weight loss was only 1.3 ± 0.2 mg for the GC coating containing 1.5 wt% graphene (denoted as GC1.5) with a load of 10 N and sliding distance of 500 m, while that of the pure CS coating reached up to 28.6 ± 0.5 mg. In vitro cytocompatibility of the GC1.5 coating was evaluated using a human marrow stem cell (hMSC) culture system. The proliferation and alkaline phosphatase, osteopontin and osteocalcin (OC) osteogenesis-related gene expression of the cells on the GC1.5 coating did not deteriorate with the adoption of graphene. Conversely, even better adhesion of the hMSCs was observed on the GC1.5 coating than on the pure CS coating. All of the results indicate that the GC1.5 coating is a good candidate for load-bearing implants.

Polymer coating of glass microballoons levitated in a focused acoustic field

International Nuclear Information System (INIS)

Young, A.T.; Lee, M.C.; Feng, I.A.; Elleman, D.D.; Wang, T.G.

1981-01-01

Inertial confinement fusion (ICF) glass microballoons (GMBs) levitated in a focusing radiator acoustic device can be coated with liquid materials by deploying the liquid into the levitation field with a stepped-horn atomizer. The GMB can be forced to the center of the coating liquid with a strong acoustically generated centering force. Water solutions of organic polymers, uv-curable liquid organic monomers, and paraffin waxes have been used to prepare solid coatings on the surface of GMBs using this technique

Coating of diamond-like carbon nanofilm on alumina by microwave plasma enhanced chemical vapor deposition process.

Science.gov (United States)

Rattanasatien, Chotiwan; Tonanon, Nattaporn; Bhanthumnavin, Worawan; Paosawatyanyong, Boonchoat

2012-01-01

Diamond-like carbon (DLC) nanofilms with thickness varied from under one hundred to a few hundred nanometers have been successfully deposited on alumina substrates by microwave plasma enhanced chemical vapor deposition (MW-PECVD) process. To obtain dense continuous DLC nanofilm coating over the entire sample surface, alumina substrates were pre-treated to enhance the nucleation density. Raman spectra of DLC films on samples showed distinct diamond peak at around 1332 cm(-1), and the broad band of amorphous carbon phase at around 1550 cm(-1). Full width at half maximum height (FWHM) values indicated good formation of diamond phase in all films. The result of nano-indentation test show that the hardness of alumina samples increase from 7.3 +/- 2.0 GPa in uncoated samples to 15.8 +/- 4.5-52.2 +/- 2.1 GPa in samples coated with DLC depending on the process conditions. It is observed that the hardness values are still in good range although the thickness of the films is less than a hundred nanometer.

Experimental analysis of a paraffin-based cold storage tank

OpenAIRE

Barbara Torregrosa-Jaime; López-Navarro, Alejandro; Corberán, José M.; Esteban-Matías, J. C.; Klinkner, L.; Payá-Herrero, Jorge

2013-01-01

[EN] The aim of this study is to characterize a paraffin-based cold storage tank. Novel experimental results are presented for this system which combines a significant amount of paraffin (1450 kg) immersed around 18 spiral-shaped coils disposed in counter-current flow. The paraffin has a phase-change temperature in the range 4 8 °C as measured by a 3-layer calorimeter. Different tests have been carried out with a constant mass flow rate and supply temperature. Around 31% of the paraffin has h...

Complete long-term corrosion protection with chemical vapor deposited graphene

DEFF Research Database (Denmark)

Yu, Feng; Camilli, Luca; Wang, Ting

2018-01-01

Despite numerous reports regarding the potential of graphene for corrosion protection, examples of chemical vapor deposited (CVD) graphene-based anticorrosive coatings able to provide long-term protection (i.e. several months) of metals have so far been absent. Here, we present a polymer-graphene......Despite numerous reports regarding the potential of graphene for corrosion protection, examples of chemical vapor deposited (CVD) graphene-based anticorrosive coatings able to provide long-term protection (i.e. several months) of metals have so far been absent. Here, we present a polymer......-graphene hybrid coating, comprising two single layers of CVD graphene sandwiched by three layers of polyvinyl butyral, which provides complete corrosion protection of commercial aluminum alloys even after 120 days of exposure to simulated seawater. The essential role played by graphene in the hybrid coating...

Preparation and Evaluation of Newly Developed Chitosan Salt Coating Dispersions for Colon Delivery without Requiring Overcoating.

Science.gov (United States)

Yamada, Kyohei; Iwao, Yasunori; Bani-Jaber, Ahmad; Noguchi, Shuji; Itai, Shigeru

2015-01-01

Although chitosan (CS) has been recognized as a good material for colon-specific drug delivery systems, an overcoating with an enteric coating polymer on the surface of CS is absolutely necessary because CS is soluble in acidic conditions before reaching the colon. In the present study, to improve its stability in the presence of acid, a newly developed CS-laurate (CS-LA) material was evaluated as a coating dispersion for the development of colon-specific drug delivery systems. Two types of CS with different molecular weights, CS250 and CS600, were used to prepare CS-LA films by the casting method. The CS250-LA films had smooth surfaces, whereas the surfaces of the CS600-LA films were rough, indicating that the CS250-LA dispersion could form a denser film than CS600-LA. Both of these CS-LA films maintained a constant shape over 22 h in a pH 1.2 HCl/NaCl buffer, where the corresponding CS films rapidly disintegrated. In addition, the CS250-LA film showed specific colon degradability in a pH 6.0 phosphate buffered solution containing 1.0% (w/v) β-glucosidase. As a result of tensile strength and elongation at the break, both CS-LA films were found to have flexible film properties. Finally, the release of acetaminophen from disks coated with CS250-LA dispersions was significantly suppressed in fluids at pH 1.2 and 6.8, whereas disks coated with CS solution rapidly released the drug in pH 1.2 fluids. Taken together, this study shows that LA modification could be a useful approach in preparing CS films with acid stability and colonic degradability properties without requiring overcoating.

Precursor-Less Coating of Nanoparticles in the Gas Phase

Directory of Open Access Journals (Sweden)

Tobias V. Pfeiffer

2015-03-01

Full Text Available This article introduces a continuous, gas-phase method for depositing thin metallic coatings onto (nanoparticles using a type of physical vapor deposition (PVD at ambient pressure and temperature. An aerosol of core particles is mixed with a metal vapor cloud formed by spark ablation by passing the aerosol through the spark zone using a hollow electrode configuration. The mixing process rapidly quenches the vapor, which condenses onto the core particles at a timescale of several tens of milliseconds in a manner that can be modeled as bimodal coagulation. Gold was deposited onto core nanoparticles consisting of silver or polystyrene latex, and silver was deposited onto gold nanoparticles. The coating morphology depends on the relative surface energies of the core and coating materials, similar to the growth mechanisms known for thin films: a coating made of a substance having a high surface energy typically results in a patchy coverage, while a coating material with a low surface energy will normally “wet” the surface of a core particle. The coated particles remain gas-borne, allowing further processing.

Impact of edible chitosan-cassava starch coatings enriched with Lippia gracilis Schauer genotype mixtures on the shelf life of guavas (Psidium guajava L.) during storage at room temperature.

Science.gov (United States)

de Aquino, Alana Bezerra; Blank, Arie Fitzgerald; Santana, Luciana Cristina Lins de Aquino

2015-03-15

The effect of edible chitosan-cassava starch (CH-CS) coatings containing a mixture of Lippia gracilis Schauer genotypes (EOM) on the shelf life of guavas during storage at room temperature for 10 days was studied. Sixteen formulations were prepared with a range of chitosan and essential oil mixtures concentrations, and the in vitro antimicrobial activity was tested. Formulations containing 2.0% cassava starch, 2.0% chitosan and 1.0%, 2.0% or 3.0% EOM were most effective in inhibiting the growth of the majority of bacteria. The edible CH-CS coating and CH-CS with 1.0% (CH-CS-EOM1) or 3.0% EOM (CH-CS-EOM3) were added to guavas and the shelf life was evaluated. On the tenth day of storage, total aerobic mesophilic bacteria and mould and yeast counts were statistically lower (p<0.05) in the CH-CS-EOM1- or CH-CS-EOM3-coated fruits than CH-CS-coated fruits. In addition, fruits coated with CH-CS or CH-CS-EOM showed no significant changes of total soluble solids content, while CH-CS-EOM-coated fruits showed lower titratable acidity than CH-CS-coated fruits at the end of storage. CH-CS-EOM3-coated guavas showed lower a(∗) and b(∗) values and higher L(∗) and hue values than those with other coatings. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of local regions near the interfaces in nanostructured multicomponent cathodic – arc – vapor – deposition (CAVD) coatings (Ti-Zr-Hf-V-Nb)N

International Nuclear Information System (INIS)

Kraus-Rekhberg, R.; Pogrebnyak, A. D.; Borisyuk, V. N.; Kaverin, M. V.; Belokur, M.A.; Ponomarev, G.; Ojoshi, K.; Takeda, J.; Beresnev, V. M.; Sobol', O. V.

2013-01-01

Multicomponent, nanostructure (Ti- Zr-Hf-V-Nb)N coatings derived using cathodic – Arc – Vapor – Deposition method, were characterized by applying SPB, (μ-PIXE), EDS and SEM-analysis), XRD methods, including ''a-sin 2 φ'' procedure. It was found that through the creation of high elastic strains of compression in coating it is possible to a significant extent enhance its oxidation resistance under high-temperature annealing. During the characterization of coatings the elements and defects’ redistribution was discovered, its segregation through thermally-stimulated diffusion and the spinoidal segregation process end, in the neighborhood of the interfaces, around grains and subgrains, without substantial change of the average nanograin dimension. (authors)

7YSZ coating prepared by PS-PVD based on heterogeneous nucleation

Directory of Open Access Journals (Sweden)

Ziqian DENG

2018-04-01

Full Text Available Plasma spray-physical vapor deposition (PS-PVD as a novel coating process based on low-pressure plasma spray (LPPS has been significantly used for thermal barrier coatings (TBCs. A coating can be deposited from liquid splats, nano-sized clusters, and the vapor phase forming different structured coatings, which shows obvious advantages in contrast to conventional technologies like atmospheric plasma spray (APS and electron beam-physical vapor deposition (EB-PVD. In addition, it can be used to produce thin, dense, and porous ceramic coatings for special applications because of its special characteristics, such as high power, very low pressure, etc. These provide new opportunities to obtain different advanced microstructures, thus to meet the growing requirements of modern functional coatings. In this work, focusing on exploiting the potential of gas-phase deposition from PS-PVD, a series of 7YSZ coating experiments with various process conditions was performed in order to better understand the deposition process in PS-PVD, where coatings were deposited on different substrates including graphite and zirconia. Meanwhile, various substrate temperatures were investigated for the same substrate. As a result, a deposition mechanism of heterogeneous nucleation has been presented showing that surface energy is an important influencing factor for coating structures. Besides, undercooling of the interface between substrate and vapor phase plays an important role in coating structures. Keywords: 7YSZ, Deposition mechanism, Heterogeneous nucleation, PS-PVD, TBC

Enhanced quantum efficiency for CsI grown on a graphite-based substrate coating

CERN Document Server

Friese, J; Homolka, J; Kastenmüller, A; Maier-Komor, P; Peter, M; Zeitelhack, K; Kienle, P; Körner, H J

1999-01-01

Quantum efficiencies (QE) in the vacuum ultraviolet (VUV) wavelength region have been measured for solid CsI layers on various substrates. The CsI films were deposited applying electron beam evaporation. The QE measurements were performed utilizing synchrotron radiation as well as light from a deuterium lamp. A GaAsP diode with a sensitivity calibration traceable to a primary radiation standard was used for normalization. For CsI layers grown on resin-stabilized graphite films a significant enhancement of QE was observed. Substrates suitable for gas detector applications and aging properties were investigated. The procedures to prepare and reproduce high quantum efficient CsI layers are described.

Preliminary experimental research to detect grease stain of petroleum pipeline by sup 1 sup 3 sup 7 Cs gamma-ray transmission method

CERN Document Server

Wang Shi Heng

2002-01-01

The experimental study on the detection of grease stain for petroleum pipeline in Karamay oil-field of Xinjiang is carried out by gamma-ray transmission method. Experimental provision consists of sup 1 sup 3 sup 7 Cs gamma radiator and NaI(Tl) scintillation detector. The response of grease stain thickness of petroleum pipeline in Karamay oil-field is ln(N sub 0 /N)=0.00548 d-0.0046, and the response of paraffin thickness is ln(N sub 0 /N)=0.00522d-0.0126. The result of experiment indicates that the response of grease stain thickness is more sensitive than the response of paraffin thickness

Fabrication of Water Jet Resistant and Thermally Stable Superhydrophobic Surfaces by Spray Coating of Candle Soot Dispersion.

Science.gov (United States)

Qahtan, Talal F; Gondal, Mohammed A; Alade, Ibrahim O; Dastageer, Mohammed A

2017-08-08

A facile synthesis method for highly stable carbon nanoparticle (CNP) dispersion in acetone by incomplete combustion of paraffin candle flame is presented. The synthesized CNP dispersion is the mixture of graphitic and amorphous carbon nanoparticles of the size range of 20-50 nm and manifested the mesoporosity with an average pore size of 7 nm and a BET surface area of 366 m 2 g -1 . As an application of this material, the carbon nanoparticle dispersion was spray coated (spray-based coating) on a glass surface to fabricate superhydrophobic (water contact angle > 150° and sliding angle fabricated from direct candle flame soot deposition (candle-based coating). This study proved that water jet resistant and thermally stable superhydrophobic surfaces can be easily fabricated by simple spray coating of CNP dispersion gathered from incomplete combustion of paraffin candle flame and this technique can be used for different applications with the potential for the large scale fabrication.

Influence of extracellular matrix coatings on implant stability and osseointegration: an animal study.

Science.gov (United States)

Stadlinger, Bernd; Pilling, Eckart; Huhle, Matthias; Mai, Ronald; Bierbaum, Susanne; Bernhardt, Ricardo; Scharnweber, Dieter; Kuhlisch, Eberhard; Hempel, Ute; Eckelt, Uwe

2007-10-01

Aim of the present study was to test the hypothesis that the application of components of the extracellular matrix such as glycosaminoglycans used as implant surface coatings in combination with collagen, with and without growth factor, can lead to enhanced ossification and thus improve implant stability compared with collagen coatings alone. Twenty miniature pigs received 120 experimental titanium implants in the mandible. Three types of surface coatings were created: (1) collagen type I (coll), (2) collagen type I/chondroitin sulphate (coll/CS), (3) collagen type I/chondroitin sulphate/BMP-4 (coll/CS/BMP). Periimplant bone formation was assessed within a defined recess along the length axis of the implant. Bone-implant contact (BIC) and bone volume density (BVD) were determined, using both histomorphometry and synchrotron radiation micro computed tomography (SRmicroCT). To measure implant stability, resonance frequency analysis was applied after implantation and 1, 3, 7, and 22 weeks after placement. BIC was highest for coll/CS coated implants, followed by coll, p = 0.082. Histomorphometric BVD did not significantly change for any coating. SRmicroCT analysis showed an increased BVD for collagen coated implants, compared with the other two surface coatings. Implant stability showed a decrease for all coatings up to the third week. At 22 weeks, all coatings showed an increase in stability without reaching their initial level. Highest stability was reached for coll coated implants, p = 0.051. It was concluded that collagen and coll/CS implant coatings have advantageous characteristics for peri-implant bone formation, compared with the further integration of BMP-4.

The influence of expanded graphite on thermal properties for paraffin/high density polyethylene/chlorinated paraffin/antimony trioxide as a flame retardant phase change material

International Nuclear Information System (INIS)

Zhang Ping; Song Lei; Lu Hongdian; Wang Jian; Hu Yuan

2010-01-01

The influences of expanded graphite (EG) on the thermal properties of chlorinated paraffin (CP) and antimony trioxide (AT) on phase change material which bases on paraffin/high density polyethylene (HDPE) are studied. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), thermogravimetric analysis-Fourier transform infrared spectrometry (TGA-FTIR), microscale combustion calorimeter (MCC) and cone calorimeter (CONE) were used to evaluate the influence of EG on paraffin/HDPE/CP/AT system. The DSC results indicated that the latent heat value of PCM could be increased when the mass fraction of HDPE was decreased in the PCM, and EG could confine the molecular heat movement of paraffin. EG could improve the thermal stability and increase the char residue at high temperature for paraffin/HDPE/CP/AT hybrid. The volatilized products formed on thermal degradation of paraffin/HDPE/CP/AT with EG showed the release of CO 2 gas was hastened and increased, and the amount of combustible gases were decreased by TGA-FTIR analysis. The MCC and CONE results presented that the flame retardant efficiency of CP/AT could be improved by adding EG in paraffin/HDPE/CP/AT system.

In vivo siRNA delivery system for targeting to the liver by poly-l-glutamic acid-coated lipoplex

Directory of Open Access Journals (Sweden)

Yoshiyuki Hattori

2014-01-01

Full Text Available In this study, we developed anionic polymer-coated liposome/siRNA complexes (lipoplexes with chondroitin sulfate C (CS, poly-l-glutamic acid (PGA and poly-aspartic acid (PAA for siRNA delivery by intravenous injection, and evaluated the biodistribution and gene silencing effect in mice. The sizes of CS-, PGA- and PAA-coated lipoplexes were about 200 nm and their ζ-potentials were negative. CS-, PGA- and PAA-coated lipoplexes did not induce agglutination after mixing with erythrocytes. In terms of biodistribution, siRNAs after intravenous administration of cationic lipoplexes were largely observed in the lungs, but those of CS-, PGA- and PAA-coated lipoplexes were in both the liver and the kidneys, indicating that siRNA might be partially released from the anionic polymer-coated lipoplexes in the blood circulation and accumulate in the kidney, although the lipoplexes can prevent the agglutination with blood components. To increase the association between siRNA and cationic liposome, we used cholesterol-modified siRNA (siRNA-Chol for preparation of the lipoplexes. When CS-, PGA- and PAA-coated lipoplexes of siRNA-Chol were injected into mice, siRNA-Chol was mainly observed in the liver, not in the kidneys. In terms of the suppression of gene expression in vivo, apolipoprotein B (ApoB mRNA in the liver was significantly reduced 48 h after single intravenous injection of PGA-coated lipoplex of ApoB siRNA-Chol (2.5 mg siRNA/kg, but not cationic, CS- and PAA-coated lipoplexes. In terms of toxicity after intravenous injection, CS-, PGA- and PAA-coated lipoplexes did not increase GOT and GPT concentrations in blood. From these findings, PGA coatings for cationic lipoplex of siRNA-Chol might produce a systemic vector of siRNA to the liver.

Production of thick uniform-coating films containing rectorite on nanofibers through the use of an automated coating machine.

Science.gov (United States)

Wu, Yang; Li, Xueyong; Shi, Xiaowen; Zhan, Yingfei; Tu, Hu; Du, Yumin; Deng, Hongbing; Jiang, Linbin

2017-01-01

When an efficient automated coating machine is used to process layer-by-layer (LBL) deposited nanofibrous mats, it causes an obvious planar effect on the surface of the mats, which can be eliminated through ultimate immersion. During this process, chitosan (CS) - rectorite (REC) intercalated composite films are built on the surface of cellulose acetate (CA) nanofibrous mats by a coating machine. Then, the immersion process is utilized to allow positively charged CS or CS-REC intercalated composites to uniformly assemble on the surface of negatively charged CA nanofibers. An investigation into the morphology of the resultant scaffolds confirms that the uniquely small pore size, high specific surface area and typically three-dimensional (3D) structure of nanofibrous mats remain present. The results of Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) indicate that it is feasible to assemble nanofibrous mats using a coating machine. The intercalated structure of CS-REC is confirmed by the results of small-angle X-ray diffraction (SAXRD) and wide-angle X-ray diffraction (WAXRD). The results of the cell experiment and antibacterial test demonstrate that the addition of REC not only has little impact on the cytocompatibility of the mats but also enhances their ability to inhibit bacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

Advanced zirconia-coated carbonyl-iron particles for acidic magnetorheological finishing of chemical-vapor-deposited ZnS and other IR materials

Science.gov (United States)

Salzman, S.; Giannechini, L. J.; Romanofsky, H. J.; Golini, N.; Taylor, B.; Jacobs, S. D.; Lambropoulos, J. C.

2015-10-01

We present a modified version of zirconia-coated carbonyl-iron (CI) particles that were invented at the University of Rochester in 2008. The amount of zirconia on the coating is increased to further protect the iron particles from corrosion when introduced to an acidic environment. Five low-pH, magnetorheological (MR) fluids were made with five acids: acetic, hydrochloric, nitric, phosphoric, and hydrofluoric. All fluids were based on the modified zirconia-coated CI particles. Off-line viscosity and pH stability were measured for all acidic MR fluids to determine the ideal fluid composition for acidic MR finishing of chemical-vapor-deposited (CVD) zinc sulfide (ZnS) and other infrared (IR) optical materials, such as hot-isostatic-pressed (HIP) ZnS, CVD zinc selenide (ZnSe), and magnesium fluoride (MgF2). Results show significant reduction in surface artifacts (millimeter-size, pebble-like structures on the finished surface) for several standard-grade CVD ZnS substrates and good surface roughness for the non-CVD MgF2 substrate when MR finished with our advanced acidic MR fluid.

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

Kinetic investigation and lifetime prediction of Cs-NIPAM-MBA-based thermo-responsive hydrogels.

Science.gov (United States)

Othman, Muhammad Bisyrul Hafi; Khan, Abbas; Ahmad, Zulkifli; Zakaria, Muhammad Razlan; Ullah, Faheem; Akil, Hazizan Md

2016-01-20

This study attempted to clarify the influence of a cross-linker, N,N-methylenebisacrylamide (MBA), and N-isopropylacrylamide (NIPAM) on the non-isothermal kinetic degradation, solid state and lifetime of hydrogels using the Flynn-Wall-Ozawa (F-W-O), Kissinger, and Coats-Redfern (C-Red) methods. The series of dual-responsive Cs-PNIPAM-MBA microgels were synthesized by soapless-emulsion free radical copolymerization in an aqueous medium at 70 °C. The thermal properties were investigated using thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) under nitrogen atmosphere. The apparent activation energy using the chosen Flynn-Wall-Ozawa and Kissinger methods showed that they fitted each other. Meanwhile, the type of solid state mechanism was determined using the Coats-Redfern method proposed for F1 (pure Cs) and F2 (Cs-PNIPAM-MBA hydrogel series) types, which comprise random nucleation with one nucleus reacting on individual particles, and random nucleation with two nuclei reacting on individual particles, respectively. On average, a higher Ea was attributed to the greater cross-linking density of the Cs hydrogel. Copyright © 2015 Elsevier Ltd. All rights reserved.

Replacing xylene with n-heptane for paraffin embedding.

Science.gov (United States)

Stockert, J C; López-Arias, B; Del Castillo, P; Romero, A; Blázquez-Castro, A

2012-10-01

In standard histological technique, aromatic solvents such as xylene and toluene are used as clearing agents between ethanol dehydration and paraffin embedding. In addition, these solvents are used for de-waxing paraffin sections. Unfortunately, these solvents are harmful and therefore adequate substitutes would be useful. We suggest the use of n-heptane as a convenient substitute for xylene. Paraffin sections of rat tissues processed with n-heptane and stained with hematoxylin-eosin or Masson's trichrome showed proper embedment, well preserved morphology and excellent staining.

Development of electrically insulating coatings for service in a lithium environment

International Nuclear Information System (INIS)

Natesan, K.; Uz, M.; Wieder, S.

2000-01-01

Several experiments were conducted to develop electrically insulating CaO coatings on a V-4Cr-4Ti alloy for application in an Li environment. The coatings were developed by vapor phase transport external to Li, and also in-situ in an Li-Ca environment at elevated temperature. In the vapor phase study, several geometrical arrangements were examined to obtain a uniform coating of Ca on the specimens, which were typically coupons measuring 5 to 10 x 5 x 1 mm. After Ca deposition from the vapor phase, the specimens were oxidized in a high-purity argon environment at 600 C to convert the deposited metal into oxide. The specimens exhibited insulating characteristics after this oxidation step. Several promising coated specimens were then exposed to high-purity Li at 500 C for 48--68 h to determine coating integrity. Microstructural characteristics of the coatings were evaluated by scanning electron microscopy and energy-dispersive X-ray analysis. Electrical resistances of the coatings were measured by a two-probe method between room temperature and 700 C before and after exposure to Li

Improvement on the electrochemical characteristics of graphite anodes by coating of the pyrolytic carbon using tumbling chemical vapor deposition

International Nuclear Information System (INIS)

Han, Young-Soo; Lee, Jai-Young

2003-01-01

The electrochemical characteristics of graphite coated with pyrolytic carbon materials using tumbling chemical vapor deposition (CVD) process have been studied for the active material of anodes in lithium ion secondary batteries. Coating of pyrolytic carbons on the surface of graphite particles, which tumble in a rotating reactor tube, was performed through the pyrolysis of liquid propane gas (LPG). The surface morphology of these graphite particles coated with pyrolytic carbon has been observed with scanning electron microscopy (SEM). The surface of graphite particles can well be covered with pyrolytic carbon by tumbling CVD. High-resolution transmission electron microscopy (HRTEM) image of these carbon particles shows that the core part is highly ordered carbon, while the shell part is disordered carbon. We have found that the new-type carbon obtained from tumbling CVD has a uniform core (graphite)-shell (pyrolytic carbon) structure. The electrochemical property of the new-type carbons has been examined using a charge-discharge cycler. The coating of pyrolytic carbon on the surface of graphite can effectively reduce the initial irreversible capacity by 47.5%. Cyclability and rate-capability of theses carbons with the core-shell structure are much better than those of bare graphite. From electrochemical impedance spectroscopy (EIS) spectra, it is found that the coating of pyrolytic carbon on the surface of graphite causes the decrease of the contact resistance in the carbon electrodes, which means the formation of solid electrolyte interface (SEI) layer is suppressed. We suggest that coating of pyrolytic carbon by the tumbling CVD is an effective method in improving the electrochemical properties of graphite electrodes for lithium ion secondary batteries

Study on paraffin/expanded graphite composite phase change thermal energy storage material

International Nuclear Information System (INIS)

Zhang Zhengguo; Fang Xiaoming

2006-01-01

A paraffin/expanded graphite composite phase change thermal energy storage material was prepared by absorbing the paraffin into an expanded graphite that has an excellent absorbability. In such a composite, the paraffin serves as a latent heat storage material and the expanded graphite acts as the supporting material, which prevents leakage of the melted paraffin from its porous structure due to the capillary and surface tension forces. The inherent structure of the expanded graphite did not change in the composite material. The solid-liquid phase change temperature of the composite PCM was the same as that of the paraffin, and the latent heat of the paraffin/expanded graphite composite material was equivalent to the calculated value based on the mass ratio of the paraffin in the composite. The heat transfer rate of the paraffin/expanded graphite composite was obviously higher than that of the paraffin due to the combination with the expanded graphite that had a high thermal conductivity. The prepared paraffin/expanded graphite composite phase change material had a large thermal storage capacity and improved thermal conductivity and did not experience liquid leakage during its solid-liquid phase change

Stability and Performance of CsPbI2Br Thin Films and Solar Cell Devices.

Science.gov (United States)

Mariotti, Silvia; Hutter, Oliver S; Phillips, Laurie J; Yates, Peter J; Kundu, Biswajit; Durose, Ken

2018-01-31

In this manuscript, the inorganic perovskite CsPbI 2 Br is investigated as a photovoltaic material that offers higher stability than the organic-inorganic hybrid perovskite materials. It is demonstrated that CsPbI 2 Br does not irreversibly degrade to its component salts as in the case of methylammonium lead iodide but instead is induced (by water vapor) to transform from its metastable brown cubic (1.92 eV band gap) phase to a yellow phase having a higher band gap (2.85 eV). This is easily reversed by heating to 350 °C in a dry environment. Similarly, exposure of unencapsulated photovoltaic devices to water vapor causes current (J SC ) loss as the absorber transforms to its more transparent (yellow) form, but this is also reversible by moderate heating, with over 100% recovery of the original device performance. NMR and thermal analysis show that the high band gap yellow phase does not contain detectable levels of water, implying that water induces the transformation but is not incorporated as a major component. Performances of devices with best efficiencies of 9.08% (V OC = 1.05 V, J SC = 12.7 mA cm -2 and FF = 68.4%) using a device structure comprising glass/ITO/c-TiO 2 /CsPbI 2 Br/Spiro-OMeTAD/Au are presented, and further results demonstrating the dependence of the performance on the preparation temperature of the solution processed CsPbI 2 Br films are shown. We conclude that encapsulation of CsPbI 2 Br to exclude water vapor should be sufficient to stabilize the cubic brown phase, making the material of interest for use in practical PV devices.

Analyses of CsI aerosol deposition tests in WIND project with ART and VICTORIA codes

International Nuclear Information System (INIS)

Yuchi, Y.; Shibazaki, H.; Kudo, T.

2000-01-01

Deposition behavior of cesium iodide (CsI) was analyzed with ART and VICTORIA-92 codes for a test of the aerosol re-vaporization test series performed in WIND project at JAERI. In the test analyzed, CsI aerosol was injected into piping of test section where metaboric acid (HBO 2 ) was placed in advance on the floor area. It was confirmed in the present analysis that similar results on the CsI deposition were obtained between ART and VICTORIA when influences of chemical interactions were negligibly small. The analysis with VICTORIA agreed satisfactorily with the test results in analytical cases that cesium metaborate (CsBO 2 ) was injected into the test section instead of CsI to simulate the pre-existence of HBO 2 effect. (author)

A Lithium Vapor Box Divertor Similarity Experiment

Science.gov (United States)

Cohen, Robert A.; Emdee, Eric D.; Goldston, Robert J.; Jaworski, Michael A.; Schwartz, Jacob A.

2017-10-01

A lithium vapor box divertor offers an alternate means of managing the extreme power density of divertor plasmas by leveraging gaseous lithium to volumetrically extract power. The vapor box divertor is a baffled slot with liquid lithium coated walls held at temperatures which increase toward the divertor floor. The resulting vapor pressure differential drives gaseous lithium from hotter chambers into cooler ones, where the lithium condenses and returns. A similarity experiment was devised to investigate the advantages offered by a vapor box divertor design. We discuss the design, construction, and early findings of the vapor box divertor experiment including vapor can construction, power transfer calculations, joint integrity tests, and thermocouple data logging. Heat redistribution of an incident plasma-based heat flux from a typical linear plasma device is also presented. This work supported by DOE Contract No. DE-AC02-09CH11466 and The Princeton Environmental Institute.

A method for producing liquid paraffin

Energy Technology Data Exchange (ETDEWEB)

Dorodnova, V.S.; Martynenko, A.G.; Pereverzev, A.N.

1983-01-01

In the known method (Sp) for producing liquid paraffins (ZhP) through processing an oil fraction by crystalline carbamide in the presence of a solvent with subsequent removal of the formed complex (Km) of KA with the liquid paraffins from the deparaffinized product, staged washing and decomposition of the complex with isolation of the liquid paraffins, in order to increase the output of liquid paraffin and to improve its quality, beta,beta'-dichlorethyl ether (khloreks) in a mixture with methylethyl ketone (MEK) or methylisobutyl ketone in a ratio of 1 is used as the solvent, the processing by the crystalline carbamide is conducted with the addition of 180 to 260 percent solvent to raw material (Sr) and the washing of the composition is conducted by a solvent in the first stage and by methylethyl ketone or methylisobutyl ketone in the second stage. The crystalline carbamide for the complex formation is taken in a conversion of 60 to 70 percent for the raw material for observing the raw material to solvent ratio of from 1 to 1.8 to 2.6 to 0.6 to 0.6. The temperature in the zone of formation of the complex is maintained at 5 to 35 degrees. The presence of beta,beta'-dichlorethyl ether, which has high selectivity relative to aromatic hydrocarbons (ArU) and to resinous compounds provides for a sharp reduction in the adsorption of the undesired components on the surface of the granules of the complex and the crystalline carbamide and to a reduction in the portion of the alkylaromatic hydrocarbons (UV) extracted into the complex, which leads to a substantial improvement in the quality of the obtained liquid paraffins.

Surface Decontamination Studies of Cs-137 and Sr-85 Using Polymer Gel

International Nuclear Information System (INIS)

Pham, L.; Nguyen, C.; Nguyen, L.

2015-01-01

Strippable polymer coating is one of the methods for effective surface decontamination to remove isotopes on the contaminated surface. This method is applying in nuclear facilities on the World. In this paper, we present the results obtained in our laboratory from product the polymer coating to apply to remove radioisotopes of "1"3"7Cs and "8"5Sr from surface of glass, stainless steel, mild steel, ceramic, PVC plastic. This polymer gel solution consist of water soluble polymer preferably polyvinyl alcohol (PVA), plasticizing agent (glycerine) and chelating agents, (citric acid) which can be sprayed or pasted on to contaminated surface. After some hours, these gel solutions was dried to form a strong thin film and it was easily peeled off from a contaminated surface with the radioactive isotopes and can be disposed off as radioactive solid waste. In this study infrared spectrophotometry technique was used to examine the interaction of the cesium and strontium ions with polyvinyl alcohol (PVA), polymer gel and the results of the study were also presented. The results showed that decontamination efficiency of "1"3"7Cs and "8"5Sr strongly depended on property, porosity and smoothness of the contaminated surface and obtained from 95-99% on glass and stainless steel, ceramic and PVC plastic surfaces. The decontamination efficiency also depended on activity and coating thickness. Optimization of film thickness is around 0.2 mm. Decontamination efficiency of Polymer gel were compared with Decongel 1101 (product from USA) on surfaces. IR spectra studies indicated that Cs and Sr ions interacted with PVA and citric acid in Polymer gel through cacboxyl (C = O) group. Polymer gel could remove of "1"3"7Cs and "8"5Sr better than PVA gel does because of citric acid, which can form chelating complex with Cs and Sr ion. (author)

Study on Thermal Degradation Characteristics and Regression Rate Measurement of Paraffin-Based Fuel

Directory of Open Access Journals (Sweden)

Songqi Hu

2015-09-01

Full Text Available Paraffin fuel has been found to have a regression rate that is higher than conventional HTPB (hydroxyl-terminated polybutadiene fuel and, thus, presents itself as an ideal energy source for a hybrid rocket engine. The energy characteristics of paraffin-based fuel and HTPB fuel have been calculated by the method of minimum free energy. The thermal degradation characteristics were measured for paraffin, pretreated paraffin, HTPB and paraffin-based fuel in different working conditions by the using differential scanning calorimetry (DSC and a thermogravimetric analyzer (TGA. The regression rates of paraffin-based fuel and HTPB fuel were tested by a rectangular solid-gas hybrid engine. The research findings showed that: the specific impulse of paraffin-based fuel is almost the same as that of HTPB fuel; the decomposition temperature of pretreated paraffin is higher than that of the unprocessed paraffin, but lower than that of HTPB; with the increase of paraffin, the initial reaction exothermic peak of paraffin-based fuel is reached in advance, and the initial reaction heat release also increases; the regression rate of paraffin-based fuel is higher than the common HTPB fuel under the same conditions; with the increase of oxidizer mass flow rate, the regression rate of solid fuel increases accordingly for the same fuel formulation.

Self-organized morphological evolution and dewetting in solvent vapor annealing of spin coated polymer blend nanostructures.

Science.gov (United States)

Roy, Sudeshna; Sharma, Ashutosh

2015-07-01

Dewetting pathways, kinetics and morphologies of thin films of phase separating polymer blends are governed by the relative mobilities of the two components. We characterize the morphological transformations of the nanostructures of a PS/PMMA blend by annealing in toluene and chloroform vapors. Toluene leads to faster reorganization of PS, whereas chloroform engenders the opposite effect. Spin coating produces a very rough PMMA rich layer that completely wets the substrate and forms a plethora of slender columns protruding through the continuous PS rich layer on top. The nanostructures were stable under long thermal annealing but in the vapor annealing, phase separation and dewetting occurred readily to form the equilibrium structures of dewetted droplets of PS on top of PMMA which also climbed around the PS droplets to form rims. Toluene and chloroform annealing required around 50 h and 1 h respectively to attain the equilibrium. Substantial differences are observed in the intermediate morphologies (heights of nanostructures, roughness and size). PMMA columns remained embedded in the dewetted PS droplets, whereas a high mobility of PMMA in chloroform allowed its rapid evacuation during dewetting to produce an intermediate swiss-cheese like morphology of PS domains. Copyright © 2015 Elsevier Inc. All rights reserved.

In vitro bioactivity, tribological property, and antibacterial ability of Ca-Si-based coatings doped with cu particles in-situ fabricated by laser cladding

Science.gov (United States)

Hou, Baoping; Yang, Zhao; Yang, Yuling; Zhang, Erlin; Qin, Gaowu

2018-03-01

The present study aimed to in-situ fabricate Ca-Si-based coatings doped with copper particles (Cu-CS coatings) to enhance in vitro bioactivity, tribological property, and antibacterial ability of Ti-6Al-4V alloy. The effects of copper addition on the multiple properties were evaluated. Our results showed that Ca2SiO4, CaTiO3, and Cu2O were in-situ fabricated after laser processing. The Cu-CS coatings exhibited an excellent wear resistance and enhanced wettability. Regarding the in vitro bioactivity, after soaking in simulated body fluid, Cu-CS coatings developed an apatite surface layer that was reduced in the coatings with higher weight percent Cu addition. The Cu-CS coatings enhanced the inhibitory action against E. coli strains, especially for the coating with a higher concentration of Cu in it. Hence, the synthesized Cu-CS coatings present excellent tribological properties, enhanced bioactivity, and antibacterial property, and, therefore, would be used to modify the surface properties of Ti-6Al-4V implants for bone tissue engineering applications.

The use of naturally occurring selectively isolated bacteria for inhibiting paraffin deposition

International Nuclear Information System (INIS)

Lazar, I.; Voicu, A.; Dobrota, S.; Petrisor, I.G.; Stefanescu, M.; Sandulescu, L.; Nicolescu, C.; Mucenica, D.

1999-01-01

One of the most severe problems at any oil fields producing paraffinic oils is that of paraffin depositions. Romania which has a long experience in oil production is also faced with this problem in many oil fields. The microbial treatment, based on the activity of naturally occurring, selectively isolated bacteria, is already proved as an effective alternative to conventional methods to prevent and remove paraffin damage. Using such kind of bacterial products, exciting results for inhibiting paraffin depositions have been obtained. In this paper results concerning the naturally occurring bacteria selectively isolated from hydrocarbon polluted sites as well as from paraffinic oils, semi-solid and solid paraffin depositions are presented. After a laboratory screening, 15 bacterial strains (BS 1-15), three bacterial consortia (BC 1-3) and a Special Bacterial Consortium (SBC1) were selected. For the selection of bacterial consortia, the classical enrichment culture method has been used. The Special Bacterial Consortium resulted from a mixture of BS 1-15 and BC 1-3 following the steps of the classical enrichment culture method. The BS 1-15, BC 1-3 and SBC1 have been tested for their performances in producing biosurfactants and biosolvents as well as for hydrocarbon utilisation. The SBC1 has been tested for its ability in degradation of hydrocarbons contained in several types of paraffinic or non-paraffinic oils, and then for inhibiting paraffin deposition on a 'flow equipment' using two types of paraffinic oils. The SBC1 has been also tested for degradation of hydrocarbons contained in semi-solid and solid paraffin depositions. The results obtained could support further applications to prevent and control paraffin depositions

The use of naturally occurring selectively isolated bacteria for inhibiting paraffin deposition

Energy Technology Data Exchange (ETDEWEB)

Lazar, I.; Voicu, A.; Dobrota, S.; Petrisor, I.G.; Stefanescu, M.; Sandulescu, L. [Institute of Biology of the Romanian Academy, Spl. Independentei 296, Bucharest (Romania); Nicolescu, C.; Mucenica, D. [PETROSTAR Ploiesti, Bdul Bucuresti 35, Ploiesti (Romania)

1999-01-01

One of the most severe problems at any oil fields producing paraffinic oils is that of paraffin depositions. Romania which has a long experience in oil production is also faced with this problem in many oil fields. The microbial treatment, based on the activity of naturally occurring, selectively isolated bacteria, is already proved as an effective alternative to conventional methods to prevent and remove paraffin damage. Using such kind of bacterial products, exciting results for inhibiting paraffin depositions have been obtained. In this paper results concerning the naturally occurring bacteria selectively isolated from hydrocarbon polluted sites as well as from paraffinic oils, semi-solid and solid paraffin depositions are presented. After a laboratory screening, 15 bacterial strains (BS 1-15), three bacterial consortia (BC 1-3) and a Special Bacterial Consortium (SBC1) were selected. For the selection of bacterial consortia, the classical enrichment culture method has been used. The Special Bacterial Consortium resulted from a mixture of BS 1-15 and BC 1-3 following the steps of the classical enrichment culture method. The BS 1-15, BC 1-3 and SBC1 have been tested for their performances in producing biosurfactants and biosolvents as well as for hydrocarbon utilisation. The SBC1 has been tested for its ability in degradation of hydrocarbons contained in several types of paraffinic or non-paraffinic oils, and then for inhibiting paraffin deposition on a `flow equipment` using two types of paraffinic oils. The SBC1 has been also tested for degradation of hydrocarbons contained in semi-solid and solid paraffin depositions. The results obtained could support further applications to prevent and control paraffin depositions

Synthesis and application of polyaminoamide as new paraffin inhibitor from vegetable oil

OpenAIRE

Chen, Gang; Tang, Ying; Zhang, Jie

2011-01-01

Abstract In this work, a series of novel paraffin inhibitor, polyaminoamide (PAA), was designed and prepared by aminolysis and poly-condensation using soybean oil and canola oil as the raw material. The property of the PAAs as paraffin inhibitor was investigated, the results show several PAA samples are potent in paraffin inhibition, and PPC-2 is the most effective one. Besides, the paraffin crystal morphology analysis was carried out to provide the mechanism of paraffin inhibition.

Controlled release of insect sex pheromones from paraffin wax and emulsions.

Science.gov (United States)

Atterholt, C A; Delwiche, M J; Rice, R E; Krochta, J M

1999-02-22

Paraffin wax and aqueous paraffin emulsions can be used as controlled release carriers for insect sex pheromones for mating disruption of orchard pests. Paraffin can be applied at ambient temperature as an aqueous emulsion, adheres to tree bark or foliage, releases pheromone for an extended period of time, and will slowly erode from bark and biodegrade in soil. Pheromone emulsions can be applied with simple spray equipment. Pheromone release-rates from paraffin were measured in laboratory flow-cell experiments. Pheromone was trapped from an air stream with an adsorbent, eluted periodically, and quantified by gas chromatography. Pheromone release from paraffin was partition-controlled, providing a constant (zero-order) release rate. A typical paraffin emulsion consisted of 30% paraffin, 4% pheromone, 4% soy oil, 1% vitamin E, 2% emulsifier, and the balance water. Soy oil and vitamin E acted as volatility suppressants. A constant release of oriental fruit moth pheromone from paraffin emulsions was observed in the laboratory for more than 100 days at 27 degreesC, with release-rates ranging from 0.4 to 2 mg/day, depending on the concentration and surface area of the dried emulsion. The use of paraffin emulsions is a viable method for direct application of insect pheromones for mating disruption. Sprayable formulations can be designed to release insect pheromones to the environment at a rate necessary for insect control by mating disruption. At temperatures below 38 degreesC, zero-order release was observed. At 38 degreesC and higher, pheromone oxidation occurred. A partition-controlled release mechanism was supported by a zero-order pheromone release-rate, low air/wax partition coefficients, and pheromone solubility in paraffin.

Metallographic techniques for evaluation of Thermal Barrier Coatings produced by Electron Beam Physical Vapor Deposition

International Nuclear Information System (INIS)

Kelly, Matthew; Singh, Jogender; Todd, Judith; Copley, Steven; Wolfe, Douglas

2008-01-01

Thermal Barrier Coatings (TBC) produced by Electron Beam Physical Vapor Deposition (EB-PVD) are primarily applied to critical hot section turbine components. EB-PVD TBC for turbine applications exhibit a complicated structure of porous ceramic columns separated by voids that offers mechanical compliance. Currently there are no standard evaluation methods for evaluating EB-PVD TBC structure quantitatively. This paper proposes a metallographic method for preparing samples and evaluating techniques to quantitatively measure structure. TBC samples were produced and evaluated with the proposed metallographic technique and digital image analysis for columnar grain size and relative intercolumnar porosity. Incorporation of the proposed evaluation technique will increase knowledge of the relation between processing parameters and material properties by incorporating a structural link. Application of this evaluation method will directly benefit areas of quality control, microstructural model development, and reduced development time for process scaling

Preparation and Characterization of Modified Montmorillonite/Paraffin Phase Change Microcapsules for Energy Storage

Directory of Open Access Journals (Sweden)

LIN Sen

2017-03-01

Full Text Available The phase change microcapsules of modified montmorillonite/paraffin were prepared by Pickering emulsion method. Analytic techniques of optical microscopy, scanning electron microscopy(SEM, infrared spectroscopy(FTIR, differential scanning calorimetry(DSC and thermogravimetry(TG were utilized for characterizing chemical structure, morphology and thermal properties. Results show that modified montmorillonite as a new type wall material has excellent performance for protecting core material of paraffin. FTIR spectra of phase change of modified montmorillonite/paraffin microcapsules shows that their characteristic peaks match with corresponding peaks of pure paraffin and modified montmorillonite. DSC results indicate that modified montmorillonite/paraffin microcapsules have similar solid-liquid phase change temperature with pure paraffin. The phase transition enthalpy values of microcapsules with paraffin contents varying from 55% to 80% are 110.5-147.2J/g, indicating that microcapsules have excellent thermal storage performance and the phase change properties can be adjusted by changing contents of paraffin. TG results confirm that modified montmorillonite/paraffin microcapsules have outstanding thermal stability. The presented study indicates that modified montmorillonite is a suitable wall material for preparing paraffin microcapsule. Modified montmorillonite/paraffin microcapsules have advantages of low cost and high performance with a great application potential in the field of thermal storage.

Coating of ceramic powders by chemical vapor deposition techniques (CVD)

International Nuclear Information System (INIS)

Haubner, R.; Lux, B.

1997-01-01

New ceramic materials with selected advanced properties can be designed by coating of ceramic powders prior to sintering. By variation of the core and coating material a large number of various powders and ceramic materials can be produced. Powders which react with the binder phase during sintering can be coated with stable materials. Thermal expansion of the ceramic materials can be adjusted by varying the coating thickness (ratio core/layer). Electrical and wear resistant properties can be optimized for electrical contacts. A fluidized bed reactor will be designed which allow the deposition of various coatings on ceramic powders. (author)

Surface structures of normal paraffins and cyclohexane monolayers and thin crystals grown on the (111) crystal face of platinum. A low-energy electron diffraction study

International Nuclear Information System (INIS)

Firment, L.E.; Somorjai, G.A.

1977-01-01

The surfaces of the normal paraffins (C 3 --C 8 ) and cyclohexane have been studied using low-energy electron diffraction (LEED). The samples were prepared by vapor deposition on the (111) face of a platinum single crystal in ultrahigh vacuum, and were studied both as thick films and as adsorbed monolayers. These molecules form ordered monolayers on the clean metal surface in the temperature range 100--220 K and at a vapor flux corresponding to 10 -7 Torr. In the adsorbed monolayers of the normal paraffins (C 4 --C 8 ), the molecules lie with their chain axes parallel to the Pt surface and Pt[110]. The paraffin monolayer structures undergo order--disorder transitions as a function of temperature. Multilayers condensed upon the ordered monolayers maintained the same orientation and packing as found in the monolayers. The surface structures of the growing organic crystals do not corresond to planes in their reported bulk crystal structures and are evidence for epitaxial growth of pseudomorphic crystal forms. Multilayers of n-octane and n-heptane condensed upon disordered monolayers have also grown with the (001) plane of the triclinic bulk crystal structures parallel to the surface. n-Butane has three monolayer structures on Pt(111) and one of the three is maintained during growth of the crystal. Cyclohexane forms an ordered monolayer, upon which a multilayer of cyclohexane grows exhibiting the (001) surface orientation of the monoclinic bulk crystal structure. Surface structures of saturated hydrocarbons are found to be very susceptible to electron beam induced damage. Surface charging interferes with LEED only at sample thicknesses greater than 200 A

Directed Vapor Deposition: Low Vacuum Materials Processing Technology

National Research Council Canada - National Science Library

Groves, J. F; Mattausch, G; Morgner, H; Hass, D. D; Wadley, H. N

2000-01-01

Directed vapor deposition (DVD) is a recently developed electron beam-based evaporation technology designed to enhance the creation of high performance thick and thin film coatings on small area surfaces...

Hybrid Physical Chemical Vapor Deposition of Superconducting Magnesium Diboride Coatings for Large Scale Radio Frequency Cavities

Science.gov (United States)

Lee, Namhoon; Withanage, Wenura; Tan, Teng; Wolak, Matthaeus; Xi, Xiaoxing

2016-03-01

Magnesium diboride (MgB2) is considered to be a great candidate for next generation superconducting radio frequency (SRF) cavities due to its higher critical temperature Tc (40 K) and increased thermodynamic critical field Hc compared to other conventional superconductors. These properties significantly reduce the BCS surface resistance (RsBCS)and residual resistance (Rres) according to theoretical studies and suggest the possibility of an enhanced accelerating field (Eacc) . We have investigated the possibility of coating the inner surface of a 3 GHz SRF cavity with MgB2 by using a hybrid physical-vapor deposition (HPCVD) system which was modified for this purpose. To simulate a real 3 GHz SRF cavity, a stainless steel mock cavity has been employed for the study. The film quality was characterized on small substrates that were placed at selected locations within the cavity. MgB2 films on stainless steel foils, niobium pieces and SiC substrates showed transition temperatures of above 36 K. Dielectric resonance measurements resulted in promising Q values as obtained for the MgB2 films grown on the various substrates. By employing the HPCVD technique, a uniform film was achieved across the cavity interior, demonstrating the feasibility of HPCVD for MgB2 coatings for SRF cavities.

Preparation of N,O-carboxymethyl chitosan coated alginate microcapsules and their application to Bifidobacterium longum BIOMA 5920.

Science.gov (United States)

Mi, Yu; Su, Ran; Fan, Dai-Di; Zhu, Xiao-Li; Zhang, Wen-Ni

2013-07-01

In order to greatly improve vitality of probiotic bacteria within the application, a novel biocompatible vehicle, N,O-carboxymethyl chitosan (NOCs) with appropriate degrees of substitution coat alginate (ALg) microparticles, was prepared by electrostatic droplet generation. The amount of chitosan (Cs) and N,O-carboxymethyl chitosan (NOCs) coated on the ALg microparticles was determined by differential scanning calorimetry. The surface morphology of ALg microparticles, Cs coated ALg microparticles and NOCs coated ALg microparticles was determined using scanning electron microscopy. The coating thickness of Cs coated ALg microparticles and that of NOCs coated ALg microparticles was directly observed with confocal laser scanning microscopy. In order to assess pH sensitivity of microparticles, the bovine serum albumin release from the microspheres was tested in acid solution (pH 2.0) for 2 h and subsequently in alkaline solution (pH 7.0) for 2 h. The survival of Bifidobacterium longum BIOMA 5920 loaded in NOCs coated with ALg microparticle was improved in simulated gastric juice (pH 2.0, for 2 h) compared to that of B. longum BIOMA 5920 loaded in ALg microparticles and Cs coated ALg microparticles. After incubation in simulated intestinal juices (pH 7.0, 2 h), the release of microencapsulated B. longum BIOMA 5920 was investigated. Copyright © 2013 Elsevier B.V. All rights reserved.

From an equilibrium based MOF adsorbent to a kinetic selective carbon molecular sieve for paraffin/iso-paraffin separation

KAUST Repository

Li, Baiyan

2016-11-04

We unveil a unique kinetic driven separation material for selectively removing linear paraffins from iso-paraffins via a molecular sieving mechanism. Subsequent carbonization and thermal treatment of CD-MOF-2, the cyclodextrin metal-organic framework, afforded a carbon molecular sieve with a uniform and reduced pore size of ca. 5.0 Å, and it exhibited highly selective kinetic separation of n-butane and n-pentane from iso-butane and iso-pentane, respectively. © The Royal Society of Chemistry.

Experimental study on heat capacity of paraffin/water phase change emulsion

International Nuclear Information System (INIS)

Huang, L.; Noeres, P.; Petermann, M.; Doetsch, C.

2010-01-01

A paraffin/water phase change emulsion is a multifunctional fluid in which fine paraffin droplets are dispersed in water by a surfactant. This paper presents an experimental study on the heat capacity of an emulsion containing 30 wt.% paraffin in a test rig. The results show that the heat capacity of the emulsion consists of the sensible heat capacity of water and that of the paraffin as well as the latent heat capacity of the paraffin during the phase transition solid-liquid. The emulsion is an attractive alternative to chilled water for comfort cooling applications, because it has a heat capacity of 50 kJ/kg from 5 to 11 deg. C, which is two times as high as that of water in the same temperature range.

Theoretical study of the Cs isotope exchange reaction of CsI + Cs' → Cs + ICs' (Contract research)

International Nuclear Information System (INIS)

Kobayashi, Takanori; Hashimoto, Masashi; Yokoyama, Keiichi

2015-12-01

To discuss the exchange reaction of Cs isotope by CsI + Cs' → Cs + ICs', the structure and chemical properties of Cs 2 I intermediate and potential energy surface of the entrance reaction are calculated using M06/def2-TZVPPD density functional calculation. The calculation shows that the reaction to the intermediate has no barrier and the two Cs-I bonds of Cs 2 I are chemically equivalent. These results suggest that the rate of the Cs exchange reaction of CsI + Cs' → Cs + ICs' is as high as the collision rate. (author)

Determination of the DBTT of Aluminide Coatings and its Influence on the Mechanical Behavior of Coated Specimens

Energy Technology Data Exchange (ETDEWEB)

Dryepondt, Sebastien N [ORNL; Pint, Bruce A [ORNL

2010-01-01

The ductility of various coatings deposited by chemical vapor deposition, pack cementation and slurry processes on Fe- and Ni-based alloys was characterized by indentation at room temperature. A hot indentation apparatus has also been developed to more rapidly determine the ductile to brittle transition temperature of coated specimens. Creep testing has been conducted on bare and coated alloy 230 (NiCrW) specimens at 800 C with a significant decrease in creep life observed. Based on the observed failure of coated 230 specimens, the impact of coating ductility on substrate creep properties is discussed.

Protective coatings for in-vessel fusion devices

International Nuclear Information System (INIS)

Brossa, F.

1984-01-01

Coatings of Al/Si, SAP (Sintered Aluminium Powder), Al 2 O 3 , TiC (low-Z material) and Ta have been developed for in-vessel component protection. Anodic oxidation, vapor depositions, reactive sputtering, chemical vapor deposition (CVD) and plasma spray have been the coating formation methods studied. AISI 316, 310, 304, Inconel 600 and Mo were adopted as base materials. the coatings were characterized in terms of composition, structure and connection with the supporting material. The behavior of coatings under H + , D + and He + irradiation in the energy range 100 eV-8 keV was tested and compared to the solid massive samples. TiC and Ta coatings were tested with thermal shock under power density pulses of 1 kW/cm 2 generated by an electron beam gun. Temperature-dependence of the erosion of TiC by vacuum arcs in a magnetic field was also studied. TiC coatings have low sputtering values, good resistance to arcing and a high chemical stability. TiC and Ta, CVD and plasma spray coatings are thermal-shock resistant. High thermal loads produce cracks but no spalling. Destruction occurred only after melting of the base material. The plasma spray coating method seems to be most appropriate for developing remote handling applications in fusion devices. (orig.)

Microstructural and superconducting properties of high current metal-organic chemical vapor deposition YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} coated conductor wires

Energy Technology Data Exchange (ETDEWEB)

Holesinger, T G; Maiorov, B; Ugurlu, O; Civale, L [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Chen, Y; Xiong, X; Xie, Y; Selvamanickam, V [SuperPower, Inc., Schenectady, NY 12304 (United States)

2009-04-15

Metal-organic chemical vapor deposition (MOCVD) on flexible, ion beam assisted deposition MgO templates has been used to produce high critical current density (J{sub c}) (Y,Sm){sub 1}Ba{sub 2}Cu{sub 3}O{sub y} (REBCO) films suitable for use in producing practical high temperature superconducting (HTS) coated conductor wires. Thick films on tape were produced with sequential additions of 0.7 {mu}m of REBCO via a reel-to-reel progression through a custom-designed MOCVD reactor. Multi-pass processing for thick film deposition is critically dependent upon minimizing surface secondary phase formation. Critical currents (I{sub c}s) of up to 600 A/cm width (t = 2.8 {mu}m, J{sub c} = 2.6 MA cm{sup -2}, 77 K, self-field) were obtained in short lengths of HTS wires. These high performance MOCVD films are characterized by closely spaced (Y,Sm){sub 2}O{sub 3} nanoparticle layers that may be tilted relative to the film normal and REBCO orientation. Small shifts in the angular dependence of J{sub c} in low and intermediate applied magnetic fields can be associated with the tilted nanoparticle layers. Also present in these films were YCuO{sub 2} nanoplates aligned with the YBCO matrix (short dimension perpendicular to the film normal), threading dislocations, and oriented composite defects (OCDs). The latter structures consist of single or multiple a-axis oriented grains coated on each side with insulating (Y,Sm){sub 2}O{sub 3} or CuO. The OCDs formed a connected network of insulating phases by the end of the fourth pass. Subsequent attempts at adding additional layers did not increase I{sub c}. There is an inconsistency between the measured J{sub c} and the observed microstructural degradation that occurs with each additional layer, suggesting that previously deposited layers are improving with each repeated reactor pass. These dynamic changes suggest a role for post-processing to optimize superconducting properties of as-deposited films, addressing issues associated with

Modifications of optical properties with ceramic coatings

International Nuclear Information System (INIS)

Besmann, T.M.; Abdel-Latif, A.I.

1990-01-01

Coatings of ceramic materials that exhibited high thermal absorptivities and emissivities were chemical vapor deposited on graphite and refractory metals. In this paper the coatings prepared were SiC and B 4 C, and the substrates used were graphite, molybdenum, titanium, and Nb-1Zr. The coatings are characterized with regard to adherence, optical properties, and response to potential harsh environments

Oxidación en vapor de agua del acero inoxidable AISI 316 recubierto con Al-Si por deposición química de vapor en lecho fluidizado

Directory of Open Access Journals (Sweden)

José Luddey Marulanda Arevalo

2014-06-01

Full Text Available Stainless steel AISI 316 was coated with aluminum-silicon by Chemical Vapor Deposition in Fluidized Bed Reactor (CVD-FBR to 540°C and subsequently heat treated to improve its mechanical properties and its behavior against oxidation, by inter diffusion of the alloying elements. Later, oxidation was performed austenitic stainless steel aluminum-silicon coated at temperatures of 700 and 750°C, in an environment with 100% steam, to evaluate their performance. Mass gain graphs were made and oxide films were analyzed by SEM and X-ray diffraction to observe the morphology of the oxides. Thermodynamic simulation was carried out during oxidation in water vapor of the substrates for possible solid phases which could be formed. The form of attack at 750°C is similar to 700°C, although the rate of oxidation is increased, because the diffusion of the alloying elements and the oxidation reactions are faster. These coatings have good resistance to oxidation in water vapor and forming an alumina surface layer which protects the substrate from corrosion attack.

Coherent Population Trapping Resonances in Cs Atomic Vapor Layers of Micrometric Thickness

Directory of Open Access Journals (Sweden)

A. Krasteva

2011-01-01

Full Text Available We report on a novel behavior of the electromagnetically induced absorption (EIA resonance observed on the D2 line of Cs for atoms confined in cells with micrometric thickness. With the enhancement of light intensity, the EIA resonance amplitude suffers from fast reduction, and even at very low intensity (W < 1 mW/cm2, resonance sign reversal takes place and electromagnetically induced transparency (EIT resonance is observed. Similar EIA resonance transformation to EIT one is not observed in conventional cm-size cells. A theoretical model is proposed to analyze the physical processes behind the EIA resonance sign reversal with light intensity. The model involves elastic interactions between Cs atoms as well as elastic interaction of atom micrometric-cell windows, both resulting in depolarization of excited state which can lead to the new observations. The effect of excited state depolarization is confirmed also by the fluorescence (absorption spectra measurement in micrometric cells with different thicknesses.

Molecular genetics of coat colour variations in White Galloway and White Park cattle.

Science.gov (United States)

Brenig, B; Beck, J; Floren, C; Bornemann-Kolatzki, K; Wiedemann, I; Hennecke, S; Swalve, H; Schütz, E

2013-08-01

White Galloway cattle exhibit three different white coat colour phenotypes, that is, well marked, strongly marked and mismarked. However, mating of individuals with the preferred well or strongly marked phenotype also results in offspring with the undesired mismarked and/or even fully black coat colour. To elucidate the genetic background of the coat colour variations in White Galloway cattle, we analysed four coat colour relevant genes: mast/stem cell growth factor receptor (KIT), KIT ligand (KITLG), melanocortin 1 receptor (MC1R) and tyrosinase (TYR). Here, we show that the coat colour variations in White Galloway cattle and White Park cattle are caused by a KIT gene (chromosome 6) duplication and aberrant insertion on chromosome 29 (Cs29 ) as recently described for colour-sided Belgian Blue. Homozygous (Cs29 /Cs29 ) White Galloway cattle and White Park cattle exhibit the mismarked phenotype, whereas heterozygous (Cs29 /wt29 ) individuals are either well or strongly marked. In contrast, fully black individuals are characterised by the wild-type chromosome 29. As known for other cattle breeds, mutations in the MC1R gene determine the red colouring. Our data suggest that the white coat colour variations in White Galloway cattle and White Park cattle are caused by a dose-dependent effect based on the ploidy of aberrant insertions and inheritance of the KIT gene on chromosome 29. © 2013 The Authors, Animal Genetics © 2013 Stichting International Foundation for Animal Genetics.

Mechanisms of radiation - chemical conversion of high-paraffinic crude oil

International Nuclear Information System (INIS)

Zaikin, Yu.A.; Zaikina, R.F.; Silverman, J.

2002-01-01

Complete text of publication follows. Regularities of radiation-thermal cracking (RTC) are studied in high-paraffinic oil. Irradiation of oil samples by 2 MeV electrons was performed using a special facility assembled at the electron accelerator ELU-4. The following characteristic RTC features were observed in oil with high contents of heavy paraffins: low level of isomerization in light RTC fractions; very high polymerization rate and low olefin contents in RTC products; relatively low yields of light fractions at low irradiation dose rates; increase in the molecular weight of the gasoline fraction as the irradiation dose rate grows. Similar intense polymerization of RTC products was observed in our experiments with such wastes of oil extraction as asphalt-pitch-paraffin sediments (APPS). Theoretically this feedstock contains great reserves of hydrogen, and, therefore, has high potential yields of light fractions. However, in this case RTC was accompanied by intense reactions of polymerization and chemical adsorption that limited the maximum yields of light RTC products to 40% in our experiments. A specific feature of APPS radiation-induced destruction is formation of the big amount of a reactive paraffinic residue. As a result of interaction with the polymerizing residue the light liquid fractions were completely absorbed and the heavy residue got denser and solidified after several days of exposure at room temperature. RTC regularities in heavy paraffinic oil differ from those observed both in highly viscous petroleum feedstock and light paraffin oils. We attribute these observations to the behavior of heavy alkyl radicals that initiate polymerization and isomerization in heavy paraffin fractions

Porous Organic Nanolayers for Coating of Solid-state Devices

Science.gov (United States)

2011-01-01

Background Highly hydrophobic surfaces can have very low surface energy and such low surface energy biological interfaces can be obtained using fluorinated coatings on surfaces. Deposition of biocompatible organic films on solid-state surfaces is attained with techniques like plasma polymerization, biomineralization and chemical vapor deposition. All these require special equipment or harsh chemicals. This paper presents a simple vapor-phase approach to directly coat solid-state surfaces with biocompatible films without any harsh chemical or plasma treatment. Hydrophilic and hydrophobic monomers were used for reaction and deposition of nanolayer films. The monomers were characterized and showed a very consistent coating of 3D micropore structures. Results The coating showed nano-textured surface morphology which can aid cell growth and provide rich molecular functionalization. The surface properties of the obtained film were regulated by varying monomer concentrations, reaction time and the vacuum pressure in a simple reaction chamber. Films were characterized by contact angle analysis for surface energy and with profilometer to measure the thickness. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the chemical composition of the coated films. Variations in the FTIR results with respect to different concentrations of monomers showed the chemical composition of the resulting films. Conclusion The presented approach of vapor-phase coating of solid-state structures is important and applicable in many areas of bio-nano interface development. The exposure of coatings to the solutions of different pH showed the stability of the coatings in chemical surroundings. The organic nanocoating of films can be used in bio-implants and many medical devices. PMID:21569579

Porous Organic Nanolayers for Coating of Solid-state Devices

Directory of Open Access Journals (Sweden)

Asghar Waseem

2011-05-01

Full Text Available Abstract Background Highly hydrophobic surfaces can have very low surface energy and such low surface energy biological interfaces can be obtained using fluorinated coatings on surfaces. Deposition of biocompatible organic films on solid-state surfaces is attained with techniques like plasma polymerization, biomineralization and chemical vapor deposition. All these require special equipment or harsh chemicals. This paper presents a simple vapor-phase approach to directly coat solid-state surfaces with biocompatible films without any harsh chemical or plasma treatment. Hydrophilic and hydrophobic monomers were used for reaction and deposition of nanolayer films. The monomers were characterized and showed a very consistent coating of 3D micropore structures. Results The coating showed nano-textured surface morphology which can aid cell growth and provide rich molecular functionalization. The surface properties of the obtained film were regulated by varying monomer concentrations, reaction time and the vacuum pressure in a simple reaction chamber. Films were characterized by contact angle analysis for surface energy and with profilometer to measure the thickness. Fourier Transform Infrared Spectroscopy (FTIR analysis revealed the chemical composition of the coated films. Variations in the FTIR results with respect to different concentrations of monomers showed the chemical composition of the resulting films. Conclusion The presented approach of vapor-phase coating of solid-state structures is important and applicable in many areas of bio-nano interface development. The exposure of coatings to the solutions of different pH showed the stability of the coatings in chemical surroundings. The organic nanocoating of films can be used in bio-implants and many medical devices.

Hyperplasia of the lymphoepithelium of NALT in rats but not in mice upon 28-day exposure to 15ppm formaldehyde vapor

NARCIS (Netherlands)

Kuper, C. F.; Oostrum, L. van; Ma-Hock, L.; Durrer, S.; Woutersen, R.A.

2011-01-01

To investigate if local lymphoid tissues are a target of FA, nasopharynx-associated lymphoid tissues (NALT) and upper-respiratory tract-draining lymph nodes were examined in a 28-day inhalation study with FA vapor in Fischer-344 rats and B6C3F1 mice.Paraffin-embedded tissues were sectioned and

Hyperplasia of the lymphoepithelium of NALT in rats but not in mice upon 28-day exposure to 15 ppm formaldehyde vapor

NARCIS (Netherlands)

Kuper, C.F.; Oostrum, van L.; Ma-Hock, I.; Durrer, S.; Woutersen, R.A.

2011-01-01

To investigate if local lymphoid tissues are a target of FA, nasopharynx-associated lymphoid tissues (NALT) and upper-respiratory tract-draining lymph nodes were examined in a 28-day inhalation study with FA vapor in Fischer-344 rats and B6C3F1 mice. Paraffin-embedded tissues were sectioned and

Fluorescence in situ hybridization on formalin-fixed and paraffin-embedded tissue

DEFF Research Database (Denmark)

Laub Petersen, Bodil; Zeuthen, Mette Christa; Pedersen, Sanni

2004-01-01

, such as quantitation of signals as in triploidy, it is possible to isolate nuclei from paraffin-embedded tissue. However, using formalin-fixed paraffin-embedded tissue, either in thin sections or as isolated nuclei, one encounters a range of technical problems, paralleling those met in immunohistochemistry. Variations...... nuclei and tissue sections from formalin-fixed, paraffin-embedded tissue....

Reduction in spasticity in stroke patient with paraffin therapy.

Science.gov (United States)

Wang, Jing; Yu, Peng; Zeng, Ming; Gu, Xudong; Liu, Yan; Xiao, Mingyue

2017-01-01

The aim of the study was to confirm whether paraffin therapy offer clinical value in the treatment of spasticity due to stroke. Fifty-two patients with spasticity in the upper limb were included. The patients were randomized into the experimental group with paraffin therapy (n = 27) and the control group with placebo therapy (n = 25). The outcome measures besides temperature examination were undertaken at time points of 0 (T0), 2 (T1) and 4 weeks (T2) following therapy treatment. The extent of spasticity was measured using Modified Ashworth Score (MAS) during passive movement at the shoulder, elbow, wrist and finger joints. Visual analogue scale (VAS) was used to evaluate the hemiplegic upper limb pain and functional activity of the upper limb motor function was evaluated by Brunnstrom recovery stage. All adverse events were recorded. MAS decreased significantly in Exp group compared with Con group, at the time points of T1 and T2, both before and immediately after paraffin therapy. Paraffin treatment failed to show remarkable improvement in pain compared with placebo-treated patient at movement at any time point. But VAS in Exp exhibited a tendency to decrease over time in shoulder, elbow, wrist and hand. With regard to the Brunnstrom score, patients in Exp showed significant improvement at the end of trial compared to the beginning. The values of temperature showed significant increment immediately after paraffin therapy at each time point in Exp group. Paraffin therapy may be a kind of noninvasive, promising method to reduce spasticity of stroke patients.

Surface conductivity of the single crystal aluminum oxide in vacuum and caesium vapors

International Nuclear Information System (INIS)

Vasilchenko, A.V.; Izhvanov, O.L.

1996-01-01

Results of measurements of surface conductivity of single-crystal aluminum oxide samples in vacuum and cesium vapors at T=620 endash 830 K and P Cs =0.13 endash 2 Pa are shown in the paper. Analysis of caesium vapor influence is carried out and ultimate characteristics of samples conductivity under operation conditions in thermionic nuclear power system (NPP) TFE are estimated. copyright 1996 American Institute of Physics

Nitrous Paraffin Hybrid, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The Nitrous Oxide Paraffin Hybrid engine (N2OP) is a proposed technology designed to provide small launch vehicles with high specific impulse, indefinitely storable...

The Shell Structure Effect on the Vapor Selectivity of Monolayer-Protected Gold Nanoparticle Sensors

Directory of Open Access Journals (Sweden)

Rui-Xuan Huang

2014-02-01

Full Text Available Four types of monolayer-protected gold nanoclusters (MPCs were synthesized and characterized as active layers of vapor sensors. An interdigitated microelectrode (IDE and quartz crystal microbalance (QCM were used to measure the electrical resistance and mass loading changes of MPC films during vapor sorption. The vapor sensing selectivity was influenced by the ligand structure of the monolayer on the surface of gold nanoparticles. The responses of MPC-coated QCM were mainly determined according to the affinity between the vapors and surface ligands of MPCs. The responses to the resistance changes of the MPC films were due to the effectiveness of the swelling when vapor was absorbed. It was observed that resistive sensitivity to polar organics could be greatly enhanced when the MPC contained ligands that contain interior polar functional groups with exterior nonpolar groups. This finding reveals that reducing interparticle attraction by using non-polar exterior groups could increase effective swelling and therefore enhance the sensitivity of MPC-coated chemiresistors.

Exogenous lipoid pneumonia caused by paraffin in an amateur fire breather.

Science.gov (United States)

Weinberg, I; Fridlender, Z G

2010-05-01

Paraffin has characteristics that make it popular among fire breathers. To describe a case of paraffin-induced lipoid pneumonia in a fire breather. The patient was evaluated clinically in relation to his occupational history. A 32-year-old man presented with dyspnoea, tachypnoea and non-productive cough of 2 h duration that started immediately following an attempt to blow fire using paraffin as the volatile substance. He was discharged from the emergency ward but returned the next day presenting again with dyspnoea accompanied by mid-sternal pain, fever (38.1 degrees C) and leucocytosis. Chest radiography showed perihilar punctuate infiltrations. A diagnosis of exogenous lipoid pneumonia caused by paraffin was made, and the patient was treated, with full recovery within a week. Fire breathers must be viewed as a population at risk of paraffin-induced lipoid pneumonia.

The Corrosion Protection of Metals by Ion Vapor Deposited Aluminum

Science.gov (United States)

Danford, M. D.

1993-01-01

A study of the corrosion protection of substrate metals by ion vapor deposited aluminum (IVD Al) coats has been carried out. Corrosion protection by both anodized and unanodized IVD Al coats has been investigated. Base metals included in the study were 2219-T87 Al, 7075-T6 Al, Titanium-6 Al-4 Vanadium (Ti-6Al-4V), 4130 steel, D6AC steel, and 4340 steel. Results reveal that the anodized IVD Al coats provide excellent corrosion protection, but good protection is also achieved by IVD Al coats that have not been anodized.

TRISO coated fuel particles with enhanced SiC properties

International Nuclear Information System (INIS)

Lopez-Honorato, E.; Tan, J.; Meadows, P.J.; Marsh, G.; Xiao, P.

2009-01-01

The silicon carbide (SiC) layer used for the formation of TRISO coated fuel particles is normally produced at 1500-1650 deg. C via fluidized bed chemical vapor deposition from methyltrichlorosilane in a hydrogen environment. In this work, we show the deposition of SiC coatings with uniform grain size throughout the coating thickness, as opposed to standard coatings which have larger grain sizes in the outer sections of the coating. Furthermore, the use of argon as the fluidizing gas and propylene as a carbon precursor, in addition to hydrogen and methyltrichlorosilane, allowed the deposition of stoichiometric SiC coatings with refined microstructure at 1400 and 1300 deg. C. The deposition of SiC at lower deposition temperatures was also advantageous since the reduced heat treatment was not detrimental to the properties of the inner pyrolytic carbon which generally occurs when SiC is deposited at 1500 deg. C. The use of a chemical vapor deposition coater with four spouts allowed the deposition of uniform and spherical coatings.

Effect of Coating Thickness on the Properties of TiN Coatings Deposited on Tool Steels Using Cathodic Arc Pvd Technique

Science.gov (United States)

Mubarak, A.; Akhter, Parvez; Hamzah, Esah; Mohd Toff, Mohd Radzi Hj.; Qazi, Ishtiaq A.

Titanium nitride (TiN) widely used as hard coating material, was coated on tool steels, namely on high-speed steel (HSS) and D2 tool steel by physical vapor deposition method. The study concentrated on cathodic arc physical vapor deposition (CAPVD), a technique used for the deposition of hard coatings for tooling applications, and which has many advantages. The main drawback of this technique, however, is the formation of macrodroplets (MDs) during deposition, resulting in films with rougher morphology. Various standard characterization techniques and equipment, such as electron microscopy, atomic force microscopy, hardness testing machine, scratch tester, and pin-on-disc machine, were used to analyze and quantify the following properties and parameters: surface morphology, thickness, hardness, adhesion, and coefficient of friction (COF) of the deposited coatings. Surface morphology revealed that the MDs produced during the etching stage, protruded through the TiN film, resulting in film with deteriorated surface features. Both coating thickness and indentation loads influenced the hardness of the deposited coatings. The coatings deposited on HSS exhibit better adhesion compared to those on D2 tool steel. Standard deviation indicates that the coating deposited with thickness around 6.7 μm showed the most stable trend of COF versus sliding distance.

Preparation of N,O-carboxymethyl chitosan coated alginate microcapsules and their application to Bifidobacterium longum BIOMA 5920

International Nuclear Information System (INIS)

Mi, Yu; Su, Ran; Fan, Dai-Di; Zhu, Xiao-Li; Zhang, Wen-Ni

2013-01-01

In order to greatly improve vitality of probiotic bacteria within the application, a novel biocompatible vehicle, N,O-carboxymethyl chitosan (NOCs) with appropriate degrees of substitution coat alginate (ALg) microparticles, was prepared by electrostatic droplet generation. The amount of chitosan (Cs) and N,O-carboxymethyl chitosan (NOCs) coated on the ALg microparticles was determined by differential scanning calorimetry. The surface morphology of ALg microparticles, Cs coated ALg microparticles and NOCs coated ALg microparticles was determined using scanning electron microscopy. The coating thickness of Cs coated ALg microparticles and that of NOCs coated ALg microparticles was directly observed with confocal laser scanning microscopy. In order to assess pH sensitivity of microparticles, the bovine serum albumin release from the microspheres was tested in acid solution (pH 2.0) for 2 h and subsequently in alkaline solution (pH 7.0) for 2 h. The survival of Bifidobacterium longum BIOMA 5920 loaded in NOCs coated with ALg microparticle was improved in simulated gastric juice (pH 2.0, for 2 h) compared to that of B. longum BIOMA 5920 loaded in ALg microparticles and Cs coated ALg microparticles. After incubation in simulated intestinal juices (pH 7.0, 2 h), the release of microencapsulated B. longum BIOMA 5920 was investigated. - Highlights: • Synthesised N,O-carboxymethyl chitosan (NOCs) coated alginate (ALg) microspheres. • Their effect on intestinal microflora was investigated in simulated gastric juices. • NOCs A coated ALg microspheres improved Bifidobacterium longum survival in SGJ. • The modified chitosan layer improved the pH-response of alginate microspheres. • NOCs A coated microspheres could be used to deliver oral bioactive compounds

Preparation of N,O-carboxymethyl chitosan coated alginate microcapsules and their application to Bifidobacterium longum BIOMA 5920

Energy Technology Data Exchange (ETDEWEB)

Mi, Yu; Su, Ran [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University (China); Fan, Dai-Di, E-mail: fandaidi@nwu.edu.cn [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University (China); Zhu, Xiao-Li [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Urban and Environmental Science, Northwest University, Taibai North Road 229, Xi' an, Shaanxi 710069 (China); Zhang, Wen-Ni [Shaanxi R and D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University (China); Shaanxi Key Laboratory of Degradable Biomedical Materials, School of Chemical Engineering, Northwest University (China)

2013-07-01

In order to greatly improve vitality of probiotic bacteria within the application, a novel biocompatible vehicle, N,O-carboxymethyl chitosan (NOCs) with appropriate degrees of substitution coat alginate (ALg) microparticles, was prepared by electrostatic droplet generation. The amount of chitosan (Cs) and N,O-carboxymethyl chitosan (NOCs) coated on the ALg microparticles was determined by differential scanning calorimetry. The surface morphology of ALg microparticles, Cs coated ALg microparticles and NOCs coated ALg microparticles was determined using scanning electron microscopy. The coating thickness of Cs coated ALg microparticles and that of NOCs coated ALg microparticles was directly observed with confocal laser scanning microscopy. In order to assess pH sensitivity of microparticles, the bovine serum albumin release from the microspheres was tested in acid solution (pH 2.0) for 2 h and subsequently in alkaline solution (pH 7.0) for 2 h. The survival of Bifidobacterium longum BIOMA 5920 loaded in NOCs coated with ALg microparticle was improved in simulated gastric juice (pH 2.0, for 2 h) compared to that of B. longum BIOMA 5920 loaded in ALg microparticles and Cs coated ALg microparticles. After incubation in simulated intestinal juices (pH 7.0, 2 h), the release of microencapsulated B. longum BIOMA 5920 was investigated. - Highlights: • Synthesised N,O-carboxymethyl chitosan (NOCs) coated alginate (ALg) microspheres. • Their effect on intestinal microflora was investigated in simulated gastric juices. • NOCs A coated ALg microspheres improved Bifidobacterium longum survival in SGJ. • The modified chitosan layer improved the pH-response of alginate microspheres. • NOCs A coated microspheres could be used to deliver oral bioactive compounds.

Study on coated layer material performance of coated particle fuel FBR (2). High temperature property and capability of coating to thick layer of TiN

International Nuclear Information System (INIS)

Naganuma, Masayuki; Mizuno, Tomoyasu

2002-08-01

'Helium Gas Cooled Coated Particle Fuel FBR' is one of attractive core concepts in the Feasibility Study on Commercialized Fast Reactor Cycle System in Japan, and the design study is presently proceeded. As one of key technologies of this concept, the coated layer material is important, and ceramics is considered to be a candidate material because of the superior refractory. Based on existing knowledge, TiN is regarded to be a possible candidate material, to which some property tests and evaluations have been conducted. In this study, preliminary tests about the high temperature property and the capability of thick layer coating of TiN have been conducted. Results of these tests come to the following conclusions. Heating tests of two kinds of TiN layer specimens coated by PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition) were conducted. As a result, as for CVD coating specimens, remarkable charge was not observed on the layer up to 2,000degC, therefore we concluded that the layer by CVD had applicability up to high temperature of actual operation level. On the other hand, as for PVD coating specimens, an unstable behavior that the layer changed to a mesh like texture was observed on a 2,000degC heated specimen, therefore the applied PVD method is not considered to be promising as the coating technique. The surface conditions of some parts inside CVD device were investigated in order to evaluate possibility of TiN thick coating (∼100 μm). As a result, around 500 μm of TiN coating layer was observed on the condition of multilayer. Therefore, we conclude that CVD has capability of coating up to thick layer in actual coated particle fuel fabrication. (author)

Carbon nanotube/paraffin/montmorillonite composite phase change material for thermal energy storage.

Science.gov (United States)

Li, Min; Guo, Qiangang; Nutt, Steven

2017-04-01

A composite phase change material (PCM) comprised of organic montmorillonite (OMMT)/paraffin/grafted multi-walled nanotube (MWNT) is synthesized via ultrasonic dispersion and liquid intercalation. The microstructure of the composite PCM has been characterized to determine the phase distribution, and thermal properties (latent heat and thermal conductivity) have been measured by differential scanning calorimetry (DSC) and a thermal constant analyzer. The results show that paraffin molecules are intercalated in the montmorillonite layers and the grafted MWNTs are dispersed in the montmorillonite layers. The latent heat is 47.1 J/g, and the thermal conductivity of the OMMT/paraffin/grafted MWNT composites is 34% higher than that of the OMMT/paraffin composites and 65% higher than that of paraffin.

New PVD Technologies for New Ordnance Coatings

Science.gov (United States)

2012-04-01

characteristics using a Tantalum and a Chrome target; 4) Deposition of Ta coatings and reactive deposition of CrN; 5) Deposition parameters affecting film...Vapor Deposition (PVD); High Power Impulse Magnetron Sputtering (HIPIMS); Modulated Pulsed Power (MPP); Tantalum; Chrome ; Ta coatings; CrN; coating...The pre-production chemicals and acids are hazardous and hexavalent Cr is a known carcinogen. Significant annual expenditures are necessary to

Effects of short-chain chlorinated paraffins on soil organisms.

Science.gov (United States)

Bezchlebová, Jitka; Cernohlávková, Jitka; Kobeticová, Klára; Lána, Jan; Sochová, Ivana; Hofman, Jakub

2007-06-01

Despite the fact that chlorinated paraffins have been produced in relatively large amounts, and high concentrations have been found in sewage sludge applied to soils, there is little information on their concentrations in soils and the effect on soil organisms. The aim of this study was to investigate the toxicity of chlorinated paraffins in soils. The effects of short-chain chlorinated paraffins (64% chlorine content) on invertebrates (Eisenia fetida, Folsomia candida, Enchytraeus albidus, Enchytraeus crypticus, Caenorhabditis elegans) and substrate-induced respiration of indigenous microorganisms were studied. Differences were found in the sensitivity of the tested organisms to short-chain chlorinated paraffins. F. candida was identified as the most sensitive organism with LC(50) and EC(50) values of 5733 and 1230 mg/kg, respectively. Toxicity results were compared with available studies and the predicted no effect concentration (PNEC) of 5.28 mg/kg was estimated for the soil environment, based on our data.

Development of Large Area CsI Photocathodes for the ALICE/HMPID RICH Detector

CERN Document Server

Hoedlmoser, H; Schyns, E

2005-01-01

The work carried out within the framework of this PhD deals with the measurement of the photoelectric properties of large area thin film Cesium Iodide (CsI) photocathodes (PCs) which are to be used as a photon converter in a proximity focusing RICH detector for High Momentum Particle Identification (HMPID) in the ALICE experiment at the LHC. The objective was to commission a VUV-scanner setup for in-situ measurements of the photoelectric response of the CsI PCs immediately after the thin film coating process and the use of this system to investigate the properties of these photon detectors. Prior to this work and prior to the finalization of the ALICE/HMPID detector design, R&D work investigating the properties of CsI PCs had been performed at CERN and at other laboratories in order to determine possible substrates and optimized thin film coating procedures. These R&D studies were usually carried out with small samples on different substrates and with various procedures with sometimes ambiguous result...

Electrically conductive carbon nanofiber/paraffin wax composites for electric thermal storage

International Nuclear Information System (INIS)

Zhang Kun; Han Baoguo; Yu Xun

2012-01-01

Highlights: ► Carbon nanofiber (CNF)/paraffin wax composite is found to be a promising electric thermal storage material. ► The thermal storage capacity of CNF/paraffin wax composite is five times of traditional electric thermal storage material. ► CNF is shown to be an effective conductive filler for the composite. - Abstract: The research of electric thermal storage (ETS) has attracted a lot of attention recently, which converts off-peak electrical energy into thermal energy and release it later at peak hours. In this study, new electric thermal storage composites are developed by employing paraffin wax as thermal storage media and carbon nanofiber (CNF) as conductive fillers. Electric heating and thermal energy release performances of the CNF/paraffin wax composites are experimentally investigated. Experimental results show that, when the composites are heated to about 70 °C, the developed electrically conductive CNF/paraffin wax composites present a thermal storage capacity of about 280 kJ/kg, which is five times of that of traditional thermal storage medium such as ceramic bricks (54 kJ/kg). The CNF/paraffin wax composites can also effectively store the thermal energy and release the thermal energy in later hours.

Photothermally Driven Refreshable Microactuators Based on Graphene Oxide Doped Paraffin.

Science.gov (United States)

Hou, Sichao; Wang, Miao; Guo, Shouwu; Su, Ming

2017-08-09

Actuators based on phase change materials (paraffin) can simultaneously produce large stroke length and large force due to thermal expansion, but the low thermal conductivity of paraffin requires high power input and long actuation time. The graphene oxide (GO) doped paraffin dynamic actuator addresses the key challenges in the design of thermal phase change actuators: Thermal conductivity and light absorbing are increased, and the response time is reduced compared to the standard phase change actuator designed with metal heating resistors. The thermal properties of GO-paraffin composites with varied loading amount are characterized to confirm the optimal loading amount of 1.0%. A multicell phase change actuator was integrated into a digital micromirror controlled optical system. A series of photothermally driven refreshable patterns were generated and confirmed with infrared imaging.

R&D results on a CsI-TTGEM based photodetector

CERN Document Server

Breskin, A; Di Mauro, A.; Martinengo, P.; Paras, D.Mayani; Molnar, L.; Nappi, E.; Paic, G.; van Hoorne, J.

2010-01-01

The very high momentum particle identification detector proposed for the ALICE upgrade is a focusing RICH using a C4F10 gaseous radiator. For the detection of Cherenkov photons, one of the options currently under investigation is to use a CsI coated Triple-Thick-GEM (CsI-TTGEM) with metallic or resistive electrodes. We will present results from the laboratory studies as well as preliminary results of beam tests of a RICH detector prototype consisting of a CaF2 radiator coupled to a 10x10 cm2 CsI-TTGEM equipped with a pad readout and GASSIPLEX-based front-end electronics. With such a prototype the detection of Cherenkov photons simultaneously with minimum ionizing particles has been achieved for the first time in a stable operation mode.

Reinforced nanohydroxyapatite/polyamide66 scaffolds by chitosan coating for bone tissue engineering.

Science.gov (United States)

Huang, Di; Zuo, Yi; Zou, Qin; Wang, Yanying; Gao, Shibo; Wang, Xiaoyan; Liu, Haohuai; Li, Yubao

2012-01-01

High porosity of scaffold is always accompanied by poor mechanical property; the aim of this study was to enhance the strength and modulus of the highly porous scaffold of nanohydroxyapatite/polyamide66 (n-HA/PA66) by coating chitosan (CS) and to investigate the effect of CS content on the scaffold physical properties and cytological properties. The results show that CS coating can reinforce the scaffold effectively. The compress modulus and strength of the CS coated n-HA/PA66 scaffolds are improved to 32.71 and 2.38 MPa, respectively, being about six times and five times of those of the uncoated scaffolds. Meanwhile, the scaffolds still exhibit a highly interconnected porous structure and the porosity is approximate about 78%, slightly lower than the value (84%) of uncoated scaffold. The cytological properties of scaffolds were also studied in vitro by cocultured with osteoblast-like MG63 cells. The cytological experiments demonstrate that the reinforced scaffolds display favorable cytocompatibility and have no significant difference with the uncoated n-HA/PA66 scaffolds. The CS reinforced n-HA/PA66 scaffolds can meet the basic mechanical requirement of bone tissue engineering scaffold, presenting a potential for biomedical application in bone reconstruction and repair. Copyright © 2011 Wiley Periodicals, Inc.

Determining the color of solid paraffines in a KNS-2 colorimeter

Energy Technology Data Exchange (ETDEWEB)

Rozova, L P; Gladyshev, V P; Ivanov, V S; Men' kov, P A

1980-01-01

A new method is presented for determining the color of solid paraffines in a recently developed KNS-2 colorimeter. The essence of this particular method lies in a comparison of the intensity of the color of a melted paraffin sample with a set of standard light filters. The color of the paraffin is expressed in conditional brands. The method is simple, reliable and has good result convergence.

The development of CVR coatings for PBR fuels

Science.gov (United States)

Barletta, R. E.; Vanier, P. E.; Dowell, M. B.; Lennartz, J. A.

Particle bed reactors (PBR's) are being developed for both space power and propulsion applications. These reactors operate with exhaust gas temperatures of 2500 to 3000 K and fuel temperatures hundreds of degrees higher. One fuel design for these reactors consists of uranium carbide encapsulated in either carbon or graphite. This fuel kernel must be protected from the coolant gas, usually H2, both to prevent attack of the kernel and to limit fission product release. Refractory carbide coatings have been proposed for this purpose. The typical coating process used for this is a chemical vapor deposition. Testing of other components have indicated the superiority of refractory carbide coatings applied using a chemical vapor reaction (CVR) process, however technology to apply these coatings to large numbers of fuel particles with diameters on the order of 500 pm were not readily available. A process to deposit these CVR coatings on surrogate fuel consisting of graphite particles is described. Several types of coatings have been applied to the graphite substrate: NbC in various thicknesses and a bilayer coating consisting of NbC and TaC with a intermediate layer of pyrolytic graphite. These coated particles have been characterized prior to test; results are presented.

Preparation and thermal energy storage properties of paraffin/expanded graphite composite phase change material

International Nuclear Information System (INIS)

Zhang, Zhengguo; Zhang, Ni; Peng, Jing; Fang, Xiaoming; Gao, Xuenong; Fang, Yutang

2012-01-01

Highlights: ► EG was obtained by microwave irradiation to prepare the paraffin/EG composite PCM. ► Composite PCM was characterized by XRD to investigate the chemical compatibility. ► Temperature profiles of the composite PCM were obtained during thermal energy storage. -- Abstract: The paraffin/expanded graphite (EG) composite phase change material (PCM) was prepared by absorbing liquid paraffin into EG, in which paraffin was chosen as the PCM. EG was produced by microwave irradiation performed at room temperature. It was found that the EG prepared at 800 W irradiation power for 10 s exhibited the maximum sorption capacity of 92 wt% for paraffin. Scanning electron microscopy images showed that paraffin was uniformly dispersed in the pores of EG. Differential scanning calorimeter analysis indicated that the melting temperature of the composite PCM was close to that of paraffin, and its latent heat was equivalent to the calculated value based on the mass fraction of paraffin in the composite. X-ray diffraction analysis showed that the composite PCM was just a combination of paraffin with EG, and no new substance was produced. Thermal energy storage performance of the composite PCM was tested in a latent thermal energy storage (LTES) system. Transients of axial and radial temperature profiles were obtained in the LTES for the composite PCM and paraffin. The thermal energy storage charging duration for the composite PCM was reduced obviously compared to paraffin.

Technique for controllable vapor-phase deposition of 1-nitro(14C)pyrene and other polycyclic aromatic hydrocarbons onto environmental particulate matter

International Nuclear Information System (INIS)

Lucas, S.V.; Lee, K.W.; Melton, C.W.; Lewtas, J.; Ball, L.M.

1991-01-01

To produce environmental particles fortified with a polycyclic aromatic hydrocarbon (PAH) for toxicology studies, an experimental apparatus was devised for deposition of the desired chemical species onto particles in a controlled and reproducible manner. The technique utilized consists of dispersion of the particles on a gaseous stream at a controlled rate, thermal vaporization of a solution of PAH, delivery of the vaporized PAH into the aerosol of particles at a controlled rate, subsequent condensation of the PAH onto the particles, and final recovery of the coated particles. The effectiveness of this approach was demonstrated by vapor-coating a 14 C-labeled PAH (1-nitro( 14 C)-pyrene) onto diesel engine exhaust particles that had previously been collected by tunnel dilution sampling techniques. Using the 14 C label as a tracer, the coated particles were characterized with respect to degree of coating, integrity of particle structure and absence of chemical decomposition of the coating substrate. The study demonstrates that the described method provides a controllable means for depositing a substance uniformly and with a high coating efficiency onto aerosolized particles. The technique was also used to vapor-coat benzo(a)pyrene onto diesel engine exhaust and urban ambient air particulate matter, and 2-nitrofluoranthene onto urban ambient air particulate matter. Coating efficiencies of about 400 micrograms/g particulate matter were routinely obtained on a single coating run, and up to 1200 micrograms/g (1200 ppm) were achieved after a second pass through the process. The coated particles were subsequently utilized in biological fate, distribution and metabolism studies

Effects of surface coating on weld growth of resistance spot-welded hot-stamped boron steels

International Nuclear Information System (INIS)

Ji, Chang Wook; Lee, Hyun Ju; Kim, Yang Do; Jo, Il Guk; Choi, Il Dong; Park, Yeong Do

2014-01-01

Aluminum-silicon-based and zinc-based metallic coatings have been widely used for hot-stamped boron steel in automotive applications. In this study, resistance spot weldability was explored by investigating the effects of the properties of metallic coating layers on heat development and nugget growth during resistance spot welding. In the case of the aluminum-silicon-coated hot-stamped boron steel, the intermetallic coating transformed into a liquid film that covered the faying interface. A wide, weldable current range was obtained with slow heat development because of low contact resistance and large current passage. In the case of the zinc-coated hot-stamped boron steel, a buildup of liquid and vapor formation under large vapor pressure was observed at the faying interface because of the high contact resistance and low vaporization temperature of the intermetallic layers. With rapid heat development, the current passage was narrow because of the limited continuous layer at the faying interface. A more significant change in nugget growth was observed in the zinc coated hot-stamped boron steel than in the aluminum-silicon-coated hot-stamped boron steel.

The effects of O-MWNTs on the performances of PVA-CS-O-MWNTs/PAN pervaporation membrane

Directory of Open Access Journals (Sweden)

Yan Xi

2017-08-01

Full Text Available Oxidized multi-wall carbon nanotubes(O-MWNTs were used as inorganic nanofillers and added in the coating solution of polyvinyl alcohol (PVA-chitosan (CS mixtures,and the PVA-CS-O-MWNTs/PAN hollow fiber membranes were prepared by the dip-coating method for the pervaporation separation of methanol (MeOH/dimethyl carbonate (DMC mixture.The process conditions including the O-MWNTs amount,heat treatment temperature,and feed temperature were investigated in detail.The results indicate that the addition of O-MWNTs can enhance the permeation flux,hydrophilicity and mechanical properties of PVA-CS-O-MWNTs/PAN membranes.The preferable conditions are that O-MWNTs amount,heat treatment temperature,feed temperature,and the concentration of MeOH are 0.1%,80℃,40℃ and 70%,respectively.Thus,the permeation fluxand MeOHselectivity can attain 210 g·m-2·h-1and 7.82,respectively.

Structure, apatite inducing ability, and corrosion behavior of chitosan/halloysite nanotube coatings prepared by electrophoretic deposition on titanium substrate.

Science.gov (United States)

Molaei, A; Amadeh, A; Yari, M; Reza Afshar, M

2016-02-01

In this study chitosan/halloysite nanotube composite (CS/HNT) coatings were deposited by electrophoretic deposition (EPD) on titanium substrate. Using HNT particles were investigated as new substituents for carbon nanotubes (CNTs) in chitosan matrix coatings. The ability of chitosan as a stabilizing, charging, and blending agent for HNT particles was exploited. Furthermore, the effects of pH, electrophoretic bath, and sonicating duration were studied on the deposition of suspensions containing HNT particles. Microstructure properties of coatings showed uniform distribution of HNT particles in chitosan matrix to form smooth nanocomposite coatings. The zeta potential results revealed that at pH around 3 there is an isoelectric point for HNT and it would have cathodic and anionic states at pH values less and more than 3, respectively. Therefore, CS/HNT composite deposits were produced in the pH range of 2.5 to 3. The apatite inducing ability of chitosan-HNT composite coating assigned that HNT particles were biocompatible because they formed carbonated hydroxyapatite particles on CS/HNT coating in corrected simulated body fluid (C-SBF). Finally, electrochemical corrosion characterizations determined that corrosion resistance in CS/HNT coating has been improved compared to bare titanium substrate. Copyright © 2015 Elsevier B.V. All rights reserved.

Strippable coating used for the TMI-2 reactor building decontamination

International Nuclear Information System (INIS)

Adams, J.W.; Dougherty, D.R.; Barletta, R.E.

1984-01-01

Strippable coating material used in the TMI-2 reactor building decontamination has been tested for Sr, Cs, and Co leachability, for radiation stability, thermal stability, and for resistance to biodegradation. It was also immersion tested in water, a water solution saturated with toluene and xylene, toluene, xylene, and liquid scintillation counting (LSC) cocktail. Leach testing resulted in all of the Cs and Co activity and most of the Sr activity being released from the coating in just a few days. Immersion resulted in swelling of the coating in all of the liquids tested. Gamma irradiation and heating of the coating did not produce any apparent physical changes in the coating to 1 x 10 8 rad and 100 0 C; however, gas generation of H 2 , CO, CO 2 was observed in both cases. Biodegradation of the coating occurred readily in soils as indicated by monitoring CO 2 produced from microbial respiration. These test results indicate that strippable coating radwaste would have to be stabilized to meet the requirements for Class B waste outlined in 10 CFR Part 61 and the NRC Draft Technical Position on Waste Form

Friction and wear properties of diamonds and diamond coatings

International Nuclear Information System (INIS)

Hayward, I.P.

1991-01-01

The recent development of chemical vapor deposition techniques for diamond growth enables bearings to be designed which exploit diamond's low friction and extreme resistance to wear. However, currently produced diamond coatings differ from natural diamond surfaces in that they are polycrystalline and faceted, and often contain appreciable amounts of non-diamond material (i.e. graphitic or amorphous carbon). Roughness, in particular, influences the friction and wear properties; rough coatings severely abrade softer materials, and can even wear natural diamond sliders. Nevertheless, the best available coatings exhibit friction coefficients as low as those of natural diamond and are highly resistant to wear. This paper reviews the tribological properties of natural diamond, and compares them with those of chemical vapor deposited diamond coatings. Emphasis is placed on the roles played by roughness and material transfer in controlling frictional behavior. (orig.)

Enhanced columnar structure in CsI layer by substrate patterning

Energy Technology Data Exchange (ETDEWEB)

Jing, T.; Cho, G.; Drewery, J.; Kaplan, S.N.; Mireshghi, A.; Perez-Mendez, V.; Wildermuth, D. [Lawrence Berkeley Lab., CA (United States); Fujieda, I. [Xerox Palo Alto Research Center, CA (United States)

1991-10-01

Columnar structure in evaporated CsI layers can be controlled by patterning substrates as well as varying evaporation conditions. Mesh-patterned substrates with various dimensions were created by spin-coating polyimide on glass or amorphous silicon substrates and defining patterns with standard photolithography technique. CsI(Tl) layers 200--1000 {mu}m were evaporated. Scintillation properties of these evaporated layers, such as light yield and speed, were equivalent to those of the source materials. Spatial resolution of X-ray detectors consisting of these layers and a linear array of X-ray detectors consisting of these layers and a linear array of Si photodiodes was evaluated by exposing them to a 25{mu}m narrow beam of X-ray. The results obtained with 200{mu}m thick CsI layers coupled to a linear photodiode array with 20 dots/mm resolution showed that the spatial resolution of CsI(Tl) evaporated on patterned substrates was about 75 {mu}m FWHM, whereas that on CsI(Tl) on flat substrates was about 230 {mu}m FWHM. Micrographs taken by SEM revealed that these layers retained the well-defined columnar structure originating from substrate patterns. Adhesion and light transmission of CsI(Tl) were also improved by patterning the substrate.

A study of calcium carbonate/multiwalled-carbon nanotubes/chitosan composite coatings on Ti–6Al–4V alloy for orthopedic implants

Energy Technology Data Exchange (ETDEWEB)

Ahmed, Rasha A., E-mail: rashaauf@yahoo.com [Chemistry Department, Faculty of Science, Taif University (Saudi Arabia); Forensic Chemistry Laboratories, Medico Legal Department, Ministry of Justice, Cairo (Egypt); Fekry, Amany M. [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt); Farghali, R.A. [Chemistry Department, Faculty of Science, Taif University (Saudi Arabia); Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)

2013-11-15

In an attempt to increase the stability, bioactivity and corrosion resistance of Ti–6Al–4V alloy, chitosan (CS) biocomposite coatings reinforced with multiwalled-carbon nanotubes (MWCNTs), and calcium carbonate (CaCO{sub 3}) for surface modification were utilized by electroless deposition. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) reveals the formation of a compact and highly crosslinked coatings. Electrochemical techniques were used to investigate the coats stability and resistivity for orthopedic implants in simulated body fluid (SBF). The results show that E{sub st} value is more positive in the following order: CaCO{sub 3}/MWCNTs/CS > CS/MWCNTs > CS > MWCNTs. The calculated i{sub corr} was 0.02 nA cm{sup −2} for CaCO{sub 3}/MWCNTs/CS which suggested a high corrosion resistance.

CS Informativeness Governs CS-US Associability

Science.gov (United States)

Ward, Ryan D.; Gallistel, C. R.; Jensen, Greg; Richards, Vanessa L.; Fairhurst, Stephen; Balsam, Peter D

2012-01-01

In a conditioning protocol, the onset of the conditioned stimulus (CS) provides information about when to expect reinforcement (the US). There are two sources of information from the CS in a delay conditioning paradigm in which the CS-US interval is fixed. The first depends on the informativeness, the degree to which CS onset reduces the average expected time to onset of the next US. The second depends only on how precisely a subject can represent a fixed-duration interval (the temporal Weber fraction). In three experiments with mice, we tested the differential impact of these two sources of information on rate of acquisition of conditioned responding (CS-US associability). In Experiment 1, we show that associability (the inverse of trials to acquisition) increases in proportion to informativeness. In Experiment 2, we show that fixing the duration of the US-US interval or the CS-US interval or both has no effect on associability. In Experiment 3, we equated the increase in information produced by varying the C̅/T̅ ratio with the increase produced by fixing the duration of the CS-US interval. Associability increased with increased informativeness, but, as in Experiment 2, fixing the CS-US duration had no effect on associability. These results are consistent with the view that CS-US associability depends on the increased rate of reward signaled by CS onset. The results also provide further evidence that conditioned responding is temporally controlled when it emerges. PMID:22468633

Bovine Serum Albumin and Chitosan Coated Silver Nanoparticles and Its Antimicrobial Activity against Oral and Nonoral Bacteria

Directory of Open Access Journals (Sweden)

León Francisco Espinosa-Cristóbal

2015-01-01

Full Text Available Antimicrobial agents have been developed for drug-resistance infections, which have been rapidly increasing; however, the control of involved microorganisms is still a challenge. In this work, SNP with bovine serum albumin (BSA and chitosan (CS coatings were prepared with an aqueous reduction method, characterized using dispersion light scattering, transmission electron microscopy, and thermal analysis. Antibacterial activity was tested on seven oral and nonoral bacteria by microdilution test and scanning electron microscopy. Six different sizes and shapes of coated SNP were prepared and used. Characterization revealed narrow size and good distribution of particles, spherical and pseudospherical shapes, and the presence of coatings on the SNP surfaces. All samples showed antimicrobial activity, although smaller sizes and CS samples had the best inhibition effects. The highest microbial resistance was shown by Gram-positive bacteria. Although coated SNP action depends on particular bacterium, BSA and CS coated SNP could be used for drug-resistance infections.

Experimental investigation of the influence of Mo contained in stainless steel on Cs chemisorption behavior

Energy Technology Data Exchange (ETDEWEB)

Di Lemma, F.G.; Nakajima, K., E-mail: nakajima.kunihisa@jaea.go.jp; Yamashita, S.; Osaka, M., E-mail: ohsaka.masahiko@jaea.go.jp

2017-02-15

Chemisorption phenomena can affect fission products (FP) retention in a nuclear reactor vessel during a severe accident (SA). Detailed information on the FP chemisorbed deposits, especially for Cs, are important for a rational decommissioning of the reactor following a SA, as for the Fukushima Daiichi Power Station. Moreover the retention of Cs will influence the source term assessment and thus improved models for this phenomenon are needed in SA codes. This paper describes the influence on Cs chemisorption of molybdenum contained in stainless steel (SS) type 316. In our experiments it was observed that Cs-Mo deposits (CsFe(MoO{sub 4}){sub 3}, Cs{sub 2}MoO{sub 4}) were formed together with CsFeSiO{sub 4}, which is the predominant compound formed by chemisorption. The Cs-Mo deposits were found to revaporize from the SS sample at 1000 °C, and thus could contribute to the source term. On the other hand, CsFeSiO{sub 4} will be probably retained in the reactor during a SA due to its stability. - Highlights: • The influence of Mo contained in SS on CsOH chemisorption was investigated. • Cs chemisorbed deposits were submitted to revaporization tests. • CsFeSiO{sub 4} was the main chemisorbed compound and stable at high temperature. • Cs{sub 2}MoO{sub 4} and Cs{sub 4}Fe(MoO{sub 4}){sub 3} were the Cs-Mo deposited phases detected. • Cs-Mo deposits re-vaporization can contribute to the accident late stage release.

Protective coatings on structural materials for energy conversion systems

International Nuclear Information System (INIS)

John, J.T.; De, P.K.; Srinivasa, R.S.

2000-01-01

Full text: Structural Materials and Components used in coal fired energy conversion systems, crude oil refineries and coal gasification plants are subjected to degradation due to oxidation, sulfidation, carbonization and halogenation. Suitable protective coatings can significantly enhance their life. Protective coatings work by forming a highly stable, self-healing and slow growing protective scale at the operating temperatures. These scales act as barriers between the corrosive environment and the alloy and prevent degradation of the substitute. Three types of scales that provide such protection are based on Al 2 O 3 , Cr 2 O 3 and SiO 2 . Aluminide coatings are major alumina forming protecting coatings, applied on nickel, cobalt and iron base alloys. Aluminide coatings are prepared by enriching the surface of a component by aluminum. In this paper the formation of aluminide coatings of nickel, IN738, Alloy 800, Zircaloy-2 and pure iron by chemical vapor deposition has been described. In this technique, Aluminum chloride vapors from bath kept at 353-373 K are carried in a stream of hydrogen gas into a Hot Walled CVD chamber kept at 1173-1373 K. The AlCl 3 vapors were allowed to react with pure aluminum whereby aluminum sub-chlorides like AlCl and AlCl 2 are produced which deposit aluminum on the substrates. At the high temperature of the deposition, aluminum diffuses into the substrate and forms the aluminide coating. The process can be represented by the reaction Al (i) + AlCl 3(g) AlCl 2(s) + AlCl 2 (g) . XRD and optical microscopic studies have characterized the coatings. On pure nickel and Alloy 800 the coating consists of Ni 2 Al 3 and NiAl respectively. On pure iron the coatings consisted of FeAl. On Zircaloy-2, ZrAl 2 was also detected. The CVD coating process, XRD and optical microscopy data will be discussed further

Preparation and thermal properties of form stable paraffin phase change material encapsulation

International Nuclear Information System (INIS)

Liu Xing; Liu Hongyan; Wang Shujun; Zhang Lu; Cheng Hua

2006-01-01

Paraffin waxes are cheap and have moderate thermal energy storage density but low thermal conductivity and, hence, require large surface area to be used in energy storage. Form stable paraffin phase change materials (PCM) in which paraffin serves as a latent heat storage material and polyolefins act as a supporting material, because of paraffin leakage, are required to be improved. The form stable paraffin PCM in the present paper was encapsulated in an inorganic silica gel polymer successfully by in situ polymerization. The differential scanning calorimeter (DSC) was used to measure its thermal properties. At the same time, the Washburn equation, which measures the wetting properties of powder materials, was used to test the hydrophilic-lipophilic properties of the PCMs. The result indicated that the enthalpy of the microencapsulated PCMs was reduced little, while their hydrophilic properties were enhanced largely

Rheology of petrolatum-paraffin oil mixtures : Applications to analogue modelling of geological processes

NARCIS (Netherlands)

Duarte, João C.; Schellart, Wouter P.; Cruden, Alexander R.

2014-01-01

Paraffins have been widely used in analogue modelling of geological processes. Petrolatum and paraffin oil are commonly used to lubricate model boundaries and to simulate weak layers. In this paper, we present rheological tests of petrolatum, paraffin oil and several homogeneous mixtures of the two.

Enhanced bulk heterojunction devices prepared by thermal and solvent vapor annealing processes

Science.gov (United States)

Forrest, Stephen R.; Thompson, Mark E.; Wei, Guodan; Wang, Siyi

2017-09-19

A method of preparing a bulk heterojunction organic photovoltaic cell through combinations of thermal and solvent vapor annealing are described. Bulk heterojunction films may prepared by known methods such as spin coating, and then exposed to one or more vaporized solvents and thermally annealed in an effort to enhance the crystalline nature of the photoactive materials.

Corrugated paraffin nanocomposite films as large stroke thermal actuators and self-activating thermal interfaces.

Science.gov (United States)

Copic, Davor; Hart, A John

2015-04-22

High performance active materials are of rapidly growing interest for applications including soft robotics, microfluidic systems, and morphing composites. In particular, paraffin wax has been used to actuate miniature pumps, solenoid valves, and composite fibers, yet its deployment is typically limited by the need for external volume constraint. We demonstrate that compact, high-performance paraffin actuators can be made by confining paraffin within vertically aligned carbon nanotube (CNT) films. This large-stroke vertical actuation is enabled by strong capillary interaction between paraffin and CNTs and by engineering the CNT morphology by mechanical compression before capillary-driven infiltration of the molten paraffin. The maximum actuation strain of the corrugated CNT-paraffin films (∼0.02-0.2) is comparable to natural muscle, yet the maximum stress is limited to ∼10 kPa by collapse of the CNT network. We also show how a CNT-paraffin film can serve as a self-activating thermal interface that closes a gap when it is heated. These new CNT-paraffin film actuators could be produced by large-area CNT growth, infiltration, and lamination methods, and are attractive for use in miniature systems due to their self-contained design.

P-T-x phase diagrams of MeF-UF4(Me=Li-Cs) systems

International Nuclear Information System (INIS)

Korenev, Yu.M.; Rykov, A.N.; Varkov, M.V.; Novoselova, A.V.

1988-01-01

Vapor composition and general pressure at three-phase equilibria in the MeF-UF 4 (Me=Li-Cs) systems are calculated using the values of independent component activities obtained earlier together with the data on fusibility diagrams. P-T and T-x projections of phase diagrams of these systems are constructed

Experimental and theoretical investigations of Cs-Ba vapor tacitron inverter for power conditioning in space power systems

International Nuclear Information System (INIS)

El-Genk, M.; Murray, C.; Wernsman, B.

1993-01-01

The operation characteristics of the Cs-Ba tacitron as a switch are investigated experimentally in three modes: (a) breakdown mode, (b) I-V mode, and (c) current modulation mode. The switching frequency, grid potentials for ignition and extinguishing of discharge, and the Cs pressure and emission conditions (Ba pressure and emitter temperature) for stable current modulation are determined. The experimental data is also used to determine the off-time required for successful ignition, and the effects of the aforementioned operation parameters on the ignition duty cycle threshold for stable modulation. Operation parameters measured include switching frequency up to 20 kHz, hold-off voltage up to 180 V, current densities in excess of 15 A/cm 2 , switch power density of 1 kW/cm 2 . and a switching efficiency in excess of 90% at collector C: realer than 30 V. The voltage drop strongly depends on the Cs pressure and to a lesser extent on the emission conditions. Increasing the Cs pressure and/or the emission current lowers the voltage drop, however, for the same initial Cs pressure and emission conditions, the voltage drop in the I-V mode is usually lower than that during current modulation. As long as the discharge current is kept lower that the.emission current, the voltage drop during stable current modulation could be as low as 3 V

Enhanced Thermo-Optical Switching of Paraffin-Wax Composite Spots under Laser Heating.

Science.gov (United States)

Said, Asmaa; Salah, Abeer; Fattah, Gamal Abdel

2017-05-12

Thermo-optical switches are of particular significance in communications networks where increasingly high switching speeds are required. Phase change materials (PCMs), in particular those based on paraffin wax, provide wealth of exciting applications with unusual thermally-induced switching properties, only limited by paraffin's rather low thermal conductivity. In this paper, the use of different carbon fillers as thermal conductivity enhancers for paraffin has been investigated, and a novel structure based on spot of paraffin wax as a thermo-optic switch is presented. Thermo-optical switching parameters are enhanced with the addition of graphite and graphene, due to the extreme thermal conductivity of the carbon fillers. Differential Scanning Calorimetry (DSC) and Scanning electron microscope (SEM) are performed on paraffin wax composites, and specific heat capacities are calculated based on DSC measurements. Thermo-optical switching based on transmission is measured as a function of the host concentration under conventional electric heating and laser heating of paraffin-carbon fillers composites. Further enhancements in thermo-optical switching parameters are studied under Nd:YAG laser heating. This novel structure can be used in future networks with huge bandwidth requirements and electric noise free remote aerial laser switching applications.

Molecular structures and thermodynamic properties of 12 gaseous cesium-containing species of nuclear safety interest: Cs 2, CsH, CsO, Cs 2O, CsX, and Cs 2X 2 (X = OH, Cl, Br, and I)

Science.gov (United States)

Badawi, Michael; Xerri, Bertrand; Canneaux, Sébastien; Cantrel, Laurent; Louis, Florent

2012-01-01

Ab initio electronic structure calculations at the coupled cluster level with a correction for the triples extrapolated to the complete basis set limit have been made for the estimation of the thermochemical properties of Cs 2, CsH, CsO, Cs 2O, CsX, and Cs 2X 2 (X = OH, Cl, Br, and I). The standard enthalpies of formation and standard molar entropies at 298 K, and the temperature dependence of the heat capacities at constant pressure were evaluated. The calculated thermochemical properties are in good agreement with their literature counterparts. For Cs 2, CsH, CsOH, Cs 2(OH) 2, CsCl, Cs 2Cl 2, CsBr, CsI, and Cs 2I 2, the calculated ΔfH298K∘ values are within chemical accuracy of the most recent experimental values. Based on the excellent agreement observed between our calculated ΔfH298K∘ values and their literature counterparts, the standard enthalpies of formation at 298 K are estimated to be the following: ΔfH298K∘ (CsO) = 17.0 kJ mol -1 and ΔfH298K∘ (Cs 2Br 2) = -575.4 kJ mol -1.

Low temperature synthesis of Zn nanowires by physical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Schroeder, Philipp; Kast, Michael; Brueckl, Hubert [Austrian Research Centers GmbH ARC, Nano- Systemtechnologies, Donau-City-Strasse 1, A-1220 Wien (Austria)

2007-07-01

We demonstrate catalytic growth of zinc nanowires by physical vapor deposition at modest temperatures of 125-175 C on various substrates. In contrast to conventional approaches using tube furnaces our home-built growth system allows to control the vapor sources and the substrate temperature separately. The silicon substrates were sputter coated with a thin gold layer as metal catalyst. The samples were heated to the growth temperature and subsequently exposed to the zinc vapor at high vacuum conditions. The work pressure was adjusted by the partial pressure of oxygen or argon flow gas. Scanning electron microscopy and atomic force microscopy characterizations revealed that the nanowires exhibit straight, uniform morphology and have diameters in the range of 50-350 nm and lengths up to 70 {mu}m. The Zn nanowires grow independently of the substrates crystal orientation via a catalytic vapor-solid growth mechanism. Since no nanowire formation was observed without gold coating, we expect that the onedimensional growth is initiated by a surface reactive Au seed. ZnO nanowires can be produced in the same preparation chamber by oxidation at 500 C in 1atm (80% Ar, 20% O{sub 2}) for 1 hour. ZnO is highly attractive for sensor applications.

Experimental setup for producing tungsten coated graphite tiles using plasma enhanced chemical vapor deposition technique for fusion plasma applications

International Nuclear Information System (INIS)

Chauhan, Sachin Singh; Sharma, Uttam; Choudhary, K.K.; Sanyasi, A.K.; Ghosh, J.; Sharma, Jayshree

2013-01-01

Plasma wall interaction (PWI) in fusion grade machines puts stringent demands on the choice of materials in terms of high heat load handling capabilities and low sputtering yields. Choice of suitable material still remains a challenge and open topic of research for the PWI community. Carbon fibre composites (CFC), Beryllium (Be), and Tungsten (W) are now being considered as first runners for the first wall components of future fusion machines. Tungsten is considered to be one of the suitable materials for the job because of its superior properties than carbon like low physical sputtering yield and high sputter energy threshold, high melting point, fairly high re-crystallization temperature, low fuel retention capabilities, low chemical sputtering with hydrogen and its isotopes and most importantly the reparability with various plasma techniques both ex-situ and in-situ. Plasma assisted chemical vapour deposition is considered among various techniques as the most preferable technique for fabricating tungsten coated graphite tiles to be used as tokamak first wall and target components. These coated tiles are more favourable compared to pure tungsten due to their light weight and easier machining. A system has been designed, fabricated and installed at SVITS, Indore for producing tungsten coated graphite tiles using Plasma Enhanced Chemical Vapor Deposition (PE-CVD) technique for Fusion plasma applications. The system contains a vacuum chamber, a turbo-molecular pump, two electrodes, vacuum gauges, mass analyzer, mass flow controllers and a RF power supply for producing the plasma using hydrogen gas. The graphite tiles will be put on one of the electrodes and WF6 gas will be inserted in a controlled manner in the hydrogen plasma to achieve the tungsten-coating with WF6 dissociation. The system is integrated at SVITS, Indore and a vacuum of the order of 3*10 -6 is achieved and glow discharge plasma has been created to test all the sub-systems. The system design with

Development of Recycling Compatible Pressure-Sensitive Adhesives and Coatings

Energy Technology Data Exchange (ETDEWEB)

Steven J. Severtson

2010-02-15

The objective of this project was the design of new water-based pressure-sensitive adhesive (PSA) products and coatings engineered for enhanced removal during the processing of recycled fiber. Research included the formulation, characterization, and performance measurements of new screenable coatings, testing of modified paper and board substrates and the design of test methods to characterize the inhibition of adhesive and coating fragmentation and relative removal efficiencies of developed formulations. This project was operated under the requirements that included commercially viable approaches be the focus, that findings be published in the open literature and that new strategies could not require changes in the methods and equipment used to produce PSA and PS labels or in the recycling process. The industrial partners benefited through the building of expertise in their company that they would not, and likely could not, have pursued if it had not been for the partnership. Results of research on water-based PSAs clearly identifies which PSA and paper facestock properties govern the fragmentation of the adhesive and provide multiple strategies for making (pressure-sensitive) PS labels for which the PSA is removed at very high efficiencies from recycling operations. The application of these results has led to the identification of several commercial products in Franklin International’s (industrial partner) product line that are recycling compatible. Several new formulations were also designed and are currently being scaled-up. Work on recycling compatible barrier coatings for corrugated containers examined the reinforcement of coatings using a small amount of exfoliated organically modified montmorillonite (OMMT). These OMMT/paraffin wax nanocomposites demonstrated significantly improved mechanical properties. Paraffin waxes containing clay were found to have significantly higher Young’s moduli and yield stress relative to the wax matrix, but the most

Thermophysical properties estimation of paraffin/graphite composite phase change material using an inverse method

International Nuclear Information System (INIS)

Lachheb, Mohamed; Karkri, Mustapha; Albouchi, Fethi; Mzali, Foued; Nasrallah, Sassi Ben

2014-01-01

Highlights: • Preparation of paraffin/graphite composites by uni-axial compression technique. • Measurement of thermophysical properties of paraffin/graphite using the periodic method. • Measurement of the experimental densities of paraffin/graphite composites. • Prediction of the effective thermal conductivity using analytical models. - Abstract: In this paper, two types of graphite were combined with paraffin in an attempt to improve thermal conductivity of paraffin phase change material (PCM): Synthetic graphite (Timrex SFG75) and graphite waste obtained from damaged Tubular graphite Heat Exchangers. These paraffin/graphite phase change material (PCM) composites are prepared by the cold uniaxial compression technique and the thermophysical properties were estimated using a periodic temperature method and an inverse technique. Results showed that the thermal conductivity and thermal diffusivity are greatly influenced by the graphite addition

Cs-137 concentrations in the muscles of Walleye Pollack

International Nuclear Information System (INIS)

Morita, T.; Yoshida, K.

2003-01-01

High concentrations of Cs-137 were detected in the muscles of Walleye Pollack (Theragra chalcogramm) collected from Kitamiyamato banks (sampling on 25 Jul. 2000), Kamui area (16 Oct. 2000) and Niigata coasts (31 Jan. 2001). The concentrations were 0.35 ± 0.01, 0.41 ± 0.01, and 0.63 ± 0.02 Bq/kg-wet, respectively. The average concentration in our past investigations was about 0.25 ± 0.01 Bq/kg-wet. Samples from other areas, the coat of Kushiro (8 May 2001), North Tishima (13 Nov. 2000) and the Sea of Okhotsk (6 May 2001), had the average concentrations. There were no such high concentrations of Cs-137 in other fish species collected from Kitamiyamato banks, Kamui area, and Niigata coasts. Fish samples with high concentrations all make the migration in the north of Japan sea. These results would indicated that samples took in Cs-137 elements from sea-water or foods on the migration route. Cs-137 concentrations in muscles of walleye pollack does not increase with the body lengths unlike other marine fishes, which enables the comparison of Cs-137 concentrations between areas without considering the body lengths. Walleye Pollac migrates in the large area in the sea of Japan and draws near other country except Japan. These habits make Walleye Pollac the excellent bio indicators to monitor oceanic radioactive pollution

Prediction of high pressure vapor-liquid equilibria with mixing rule using ASOG group contribution method

Energy Technology Data Exchange (ETDEWEB)

Tochigi, K.; Kojima, K.; Kurihara, K.

1985-02-01

To develop a widely applicable method for predicting high-pressure vapor-liquid equilibria by the equation of state, a mixing rule is proposed in which mixture energy parameter ''..cap alpha..'' of theSoave-RedlichKwong, Peng-Robinson, and Martin cubic equations of state is expressed by using the ASOG group contribution method. The group pair parameters are then determined for 14 group pairs constituted by six groups, i.e. CH/sub 4/, CH/sub 3/, CH/sub 2/, N/sub 2/, H/sub 2/, and CO/sub 2/ groups. By using the group pair parameters determined, high-pressure vapor-liquid equilibria are predicted with good accuracy for binary and ternary systems constituted by n-paraffins, nitrogen, hydrogen, and carbon dioxide in the temperature range of 100 - 450K.

Investigation of metallurgical coatings for automotive applications

Science.gov (United States)

Su, Jun Feng

Metallurgical coatings have been widely used in the automotive industry from component machining, engine daily running to body decoration due to their high hardness, wear resistance, corrosion resistance and low friction coefficient. With high demands in energy saving, weight reduction and limiting environmental impact, the use of new materials such as light Aluminum/magnesium alloys with high strength-weight ratio for engine block and advanced high-strength steel (AHSS) with better performance in crash energy management for die stamping, are increasing. However, challenges are emerging when these new materials are applied such as the wear of the relative soft light alloys and machining tools for hard AHSS. The protective metallurgical coatings are the best option to profit from these new materials' advantages without altering largely in mass production equipments, machinery, tools and human labor. In this dissertation, a plasma electrolytic oxidation (PEO) coating processing on aluminum alloys was introduced in engine cylinder bores to resist wear and corrosion. The tribological behavior of the PEO coatings under boundary and starve lubrication conditions was studied experimentally and numerically for the first time. Experimental results of the PEO coating demonstrated prominent wear resistance and low friction, taking into account the extreme working conditions. The numerical elastohydrodynamic lubrication (EHL) and asperity contact based tribological study also showed a promising approach on designing low friction and high wear resistant PEO coatings. Other than the fabrication of the new coatings, a novel coating evaluation methodology, namely, inclined impact sliding tester was presented in the second part of this dissertation. This methodology has been developed and applied in testing and analyzing physical vapor deposition (PVD)/ chemical vapor deposition (CVD)/PEO coatings. Failure mechanisms of these common metallurgical hard coatings were systematically

A PMMA coated PMN–PT single crystal resonator for sensing chemical agents

International Nuclear Information System (INIS)

Frank, Michael; Kassegne, Sam; Moon, Kee S

2010-01-01

A highly sensitive lead magnesium niobate–lead titanate (PMN–PT) single crystal resonator coated with a thin film of polymethylmethacrylate (PMMA) useful for detecting chemical agents such as acetone, methanol, and isopropyl alcohol is presented. Swelling of the cured PMMA polymer layer in the presence of acetone, methanol, and isopropyl alcohol vapors is sensed as a mass change transduced to an electrical signal by the PMN–PT thickness shear mode sensor. Frequency change in the PMN–PT sensor is demonstrated to vary according to the concentration of the chemical vapor present within the sensing chamber. For acetone, the results indicate a frequency change more than 6000 times greater than that which would be expected from a quartz crystal microbalance coated with PMMA. This study is the first of its kind to demonstrate vapor loading of adsorbed chemical agents onto a polymer coated PMN–PT resonator

Photovoltaic Performance of Vapor-Assisted Solution-Processed Layer Polymorph of Cs3Sb2I9.

Science.gov (United States)

Singh, Anupriya; Boopathi, Karunakara Moorthy; Mohapatra, Anisha; Chen, Yang Fang; Li, Gang; Chu, Chih Wei

2018-01-24

The presence of toxic lead (Pb) remains a major obstruction to the commercial application of perovskite solar cells. Although antimony (Sb)-based perovskite-like structures A 3 M 2 X 9 can display potentially useful photovoltaic behavior, solution-processed Sb-based perovskite-like structures usually favor the dimer phase, which has poor photovoltaic properties. In this study, we prepared a layered polymorph of Cs 3 Sb 2 I 9 through solution-processing and studied its photovoltaic properties. The exciton binding energy and exciton lifetime of the layer-form Cs 3 Sb 2 I 9 were approximately 100 meV and 6 ns, respectively. The photovoltaic properties of the layered polymorph were superior to those of the dimer polymorph. A solar cell incorporating the layer-form Cs 3 Sb 2 I 9 exhibited an open-circuit voltage of 0.72 V and a power conversion efficiency of 1.5%-the highest reported for an all-inorganic Sb-based perovskite.

Comparison of some coating techniques to fabricate barrier layers on packaging materials

Energy Technology Data Exchange (ETDEWEB)

Hirvikorpi, Terhi, E-mail: terhi.hirvikorpi@vtt.f [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Vaehae-Nissi, Mika, E-mail: mika.vaha-nissi@vtt.f [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Harlin, Ali, E-mail: ali.harlin@vtt.f [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Karppinen, Maarit, E-mail: maarit.karppinen@tkk.f [Laboratory of Inorganic Chemistry, Department of Chemistry, Aalto University School of Science and Technology, Kemistintie 1, P.O. Box 16100, FI-00076 AALTO (Finland)

2010-07-30

Atomic layer deposition (ALD), electron beam evaporation, magnetron sputtering and a sol-gel method were used to deposit thin aluminum oxide coatings onto two different fiber-based packaging materials of commercial board grades coated with synthetic and biodegradable polymers. Significant decreases in both the water vapor and oxygen permeation rates were observed. With each technique the barrier performance was improved. However, among the techniques tested ALD was found to be most suitable. Our results moreover revealed that biodegradable polylactic acid-coated paperboard with a 25-nm thick layer of aluminum oxide grown by ALD on top of it showed promising barrier characteristics against water vapor and oxygen.

Comparison of some coating techniques to fabricate barrier layers on packaging materials

International Nuclear Information System (INIS)

Hirvikorpi, Terhi; Vaehae-Nissi, Mika; Harlin, Ali; Karppinen, Maarit

2010-01-01

Atomic layer deposition (ALD), electron beam evaporation, magnetron sputtering and a sol-gel method were used to deposit thin aluminum oxide coatings onto two different fiber-based packaging materials of commercial board grades coated with synthetic and biodegradable polymers. Significant decreases in both the water vapor and oxygen permeation rates were observed. With each technique the barrier performance was improved. However, among the techniques tested ALD was found to be most suitable. Our results moreover revealed that biodegradable polylactic acid-coated paperboard with a 25-nm thick layer of aluminum oxide grown by ALD on top of it showed promising barrier characteristics against water vapor and oxygen.

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

Magnetization of Paraffin-Based Magnetic Nanocolloids

Science.gov (United States)

Dikanskii, Yu. I.; Ispiryan, A. G.; Kunikin, S. A.; Radionov, A. V.

2018-01-01

Using paraffin-based magnetic nanocolloids as an example, the reasons for maxima in the temperature dependence of the magnetic susceptibility of magnetic colloids have been discussed. The behavior of these dependences in a wide temperature interval has been analyzed for colloids in solid and liquid states. It has been concluded that the maximum observed at the melting point of paraffin can be attributed to freezing Brownian degrees of freedom in magnetite coarse particles, the magnetic moment of which is intimately related to the solid matrix. The second main maximum, which arises in the solid state, is explained by the superparamagnetic-magnetically hard transition of most fine particles at lower temperatures. It has been noted that the flatness of this maximum results from the polydispersity of the magnetic nanoparticle ensemble.

Thermal shock testing of low-Z coatings with pulsed hydrogen beams

International Nuclear Information System (INIS)

Nakamura, Kazuyuki

1982-03-01

Thermal shock testing of candidate low-Z surface coatings for JT-60 application has been made by using a pulsed hydrogen beam apparatus which is operated at a power density of 2KW/cm 2 . The materials tested are PVD (Physical Vapor Deposited) TiC and PVD and CVD (Chemical Vapor Deposited) TiN on molybdenum and Inconel 625. The result shows that CVD TiC on Mo and CVD TiN on Inconel are the most interesting choices for the coating-substrate combinations. (author)

One-step fabrication of biocompatible chitosan-coated ZnS and ZnS:Mn2+ quantum dots via a γ-radiation route

Science.gov (United States)

Chang, Shu-Quan; Kang, Bin; Dai, Yao-Dong; Zhang, Hong-Xu; Chen, Da

2011-11-01

Biocompatible chitosan-coated ZnS quantum dots [CS-ZnS QDs] and chitosan-coated ZnS:Mn2+ quantum dots [CS-ZnS:Mn2+ QDs] were successfully fabricated via a convenient one-step γ-radiation route. The as-obtained QDs were around 5 nm in diameter with excellent water-solubility. These QDs emitting strong visible blue or orange light under UV excitation were successfully used as labels for PANC-1 cells. The cell experiments revealed that CS-ZnS and CS-ZnS:Mn2+ QDs showed low cytotoxicity and good biocompatibility, which offered possibilities for further biomedical applications. Moreover, this convenient synthesis strategy could be extended to fabricate other nanoparticles coated with chitosan. PACS: 81.07.Ta; 78.67.Hc; 82.35.Np; 87.85.Rs.

Molecular CsF 5 and CsF 2 +

KAUST Repository

Rogachev, Andrey Yu.; Miao, Mao-sheng; Merino, Gabriel; Hoffmann, Roald

2015-01-01

D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

Molecular CsF 5 and CsF 2 +

KAUST Repository

Rogachev, Andrey Yu.

2015-06-03

D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

Sintered tantalum carbide coatings on graphite substrates: Highly reliable protective coatings for bulk and epitaxial growth

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Daisuke; Suzumura, Akitoshi; Shigetoh, Keisuke [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)

2015-02-23

Highly reliable low-cost protective coatings have been sought after for use in crucibles and susceptors for bulk and epitaxial film growth processes involving wide bandgap materials. Here, we propose a production technique for ultra-thick (50–200 μmt) tantalum carbide (TaC) protective coatings on graphite substrates, which consists of TaC slurry application and subsequent sintering processes, i.e., a wet ceramic process. Structural analysis of the sintered TaC layers indicated that they have a dense granular structure containing coarse grain with sizes of 10–50 μm. Furthermore, no cracks or pinholes penetrated through the layers, i.e., the TaC layers are highly reliable protective coatings. The analysis also indicated that no plastic deformation occurred during the production process, and the non-textured crystalline orientation of the TaC layers is the origin of their high reliability and durability. The TaC-coated graphite crucibles were tested in an aluminum nitride (AlN) sublimation growth process, which involves extremely corrosive conditions, and demonstrated their practical reliability and durability in the AlN growth process as a TaC-coated graphite. The application of the TaC-coated graphite materials to crucibles and susceptors for use in bulk AlN single crystal growth, bulk silicon carbide (SiC) single crystal growth, chemical vapor deposition of epitaxial SiC films, and metal-organic vapor phase epitaxy of group-III nitrides will lead to further improvements in crystal quality and reduced processing costs.

Sintered tantalum carbide coatings on graphite substrates: Highly reliable protective coatings for bulk and epitaxial growth

International Nuclear Information System (INIS)

Nakamura, Daisuke; Suzumura, Akitoshi; Shigetoh, Keisuke

2015-01-01

Highly reliable low-cost protective coatings have been sought after for use in crucibles and susceptors for bulk and epitaxial film growth processes involving wide bandgap materials. Here, we propose a production technique for ultra-thick (50–200 μmt) tantalum carbide (TaC) protective coatings on graphite substrates, which consists of TaC slurry application and subsequent sintering processes, i.e., a wet ceramic process. Structural analysis of the sintered TaC layers indicated that they have a dense granular structure containing coarse grain with sizes of 10–50 μm. Furthermore, no cracks or pinholes penetrated through the layers, i.e., the TaC layers are highly reliable protective coatings. The analysis also indicated that no plastic deformation occurred during the production process, and the non-textured crystalline orientation of the TaC layers is the origin of their high reliability and durability. The TaC-coated graphite crucibles were tested in an aluminum nitride (AlN) sublimation growth process, which involves extremely corrosive conditions, and demonstrated their practical reliability and durability in the AlN growth process as a TaC-coated graphite. The application of the TaC-coated graphite materials to crucibles and susceptors for use in bulk AlN single crystal growth, bulk silicon carbide (SiC) single crystal growth, chemical vapor deposition of epitaxial SiC films, and metal-organic vapor phase epitaxy of group-III nitrides will lead to further improvements in crystal quality and reduced processing costs

Purity of paraffins used in drugs and cosmetics

Energy Technology Data Exchange (ETDEWEB)

Monarca, S; Fagioli, F; Morozzi, G

1981-01-01

A previously developed technique for the determination of polycyclic aromatic hydrocarbons (PAH's) in purified petroleum products was applied to some fully-refined paraffin samples for cosmetic and medicinal uses. The analytical procedure provided identification and quantitative assay for ng/g amounts of two well known carcinogenic PAH's, benzo-a-pyrene and benzoflouranthene. The method is compared with rapid pharmacopoeial tests based on different quality criteria. A lack of agreement between PAH content in paraffin samples and the results of the pharmacopoeial tests was noted. (1 diagram, 49 references, 5 tables)

Uniform Fe3O4 coating on flower-like ZnO nanostructures by atomic layer deposition for electromagnetic wave absorption.

Science.gov (United States)

Wan, Gengping; Wang, Guizhen; Huang, Xianqin; Zhao, Haonan; Li, Xinyue; Wang, Kan; Yu, Lei; Peng, Xiange; Qin, Yong

2015-11-21

An elegant atomic layer deposition (ALD) method has been employed for controllable preparation of a uniform Fe3O4-coated ZnO (ZnO@Fe3O4) core-shell flower-like nanostructure. The Fe3O4 coating thickness of the ZnO@Fe3O4 nanostructure can be tuned by varying the cycle number of ALD Fe2O3. When serving as additives for microwave absorption, the ZnO@Fe3O4-paraffin composites exhibit a higher absorption capacity than the ZnO-paraffin composites. For ZnO@500-Fe3O4, the effective absorption bandwidth below -10 dB can reach 5.2 GHz and the RL values below -20 dB also cover a wide frequency range of 11.6-14.2 GHz when the coating thickness is 2.3 mm, suggesting its potential application in the treatment of the electromagnetic pollution problem. On the basis of experimental observations, a mechanism has been proposed to understand the enhanced microwave absorption properties of the ZnO@Fe3O4 composites.

Effective melanin depigmentation of human and murine ocular tissues: an improved method for paraffin and frozen sections.

Directory of Open Access Journals (Sweden)

Caroline Manicam

Full Text Available PURPOSE: The removal of excessive melanin pigments that obscure ocular tissue morphology is important to address scientific questions and for differential diagnosis of ocular tumours based on histology. Thus, the goal of the present study was to establish an effective and fast melanin bleaching method for paraffin and frozen mouse and human ocular tissues. METHODS: Paraffin-embedded and frozen ocular specimens from mice and human donors were subjected to bleaching employing two methods. The first employed potassium permanganate (KMnO4 with oxalic acid, and the second 10% hydrogen peroxide (H2O2. To determine optimal bleaching conditions, depigmentation was carried out at various incubation times. The effect of diluents used for 10% H2O2 was assessed using phosphate-buffered saline (PBS, and deionized water. Three different slide types and two fixatives, which were ice-cold acetone with 80% methanol, and 4% paraformaldehyde (PFA were used to determine the optimal conditions for better tissue adherence during bleaching. All tissues were stained in hematoxylin and eosin for histological evaluation. RESULTS: Optimal bleaching was achieved using warm 10% H2O2 diluted in PBS at 65°C for 120 minutes. Chromium-gelatin-coated slides prevented tissue detachment. Adherence of cryosections was also improved with post-fixation using 4% PFA and overnight air-drying at RT after cryosectioning. Tissue morphology was preserved under these conditions. Conversely, tissues bleached in KMnO4/oxalic acid demonstrated poor depigmentation with extensive tissue damage. CONCLUSIONS: Warm dilute H2O2 at 65°C for 120 minutes rapidly and effectively bleached both cryo- and paraffin sections of murine and human ocular tissues.

Effective melanin depigmentation of human and murine ocular tissues: an improved method for paraffin and frozen sections.

Science.gov (United States)

Manicam, Caroline; Pitz, Susanne; Brochhausen, Christoph; Grus, Franz H; Pfeiffer, Norbert; Gericke, Adrian

2014-01-01

The removal of excessive melanin pigments that obscure ocular tissue morphology is important to address scientific questions and for differential diagnosis of ocular tumours based on histology. Thus, the goal of the present study was to establish an effective and fast melanin bleaching method for paraffin and frozen mouse and human ocular tissues. Paraffin-embedded and frozen ocular specimens from mice and human donors were subjected to bleaching employing two methods. The first employed potassium permanganate (KMnO4) with oxalic acid, and the second 10% hydrogen peroxide (H2O2). To determine optimal bleaching conditions, depigmentation was carried out at various incubation times. The effect of diluents used for 10% H2O2 was assessed using phosphate-buffered saline (PBS), and deionized water. Three different slide types and two fixatives, which were ice-cold acetone with 80% methanol, and 4% paraformaldehyde (PFA) were used to determine the optimal conditions for better tissue adherence during bleaching. All tissues were stained in hematoxylin and eosin for histological evaluation. Optimal bleaching was achieved using warm 10% H2O2 diluted in PBS at 65°C for 120 minutes. Chromium-gelatin-coated slides prevented tissue detachment. Adherence of cryosections was also improved with post-fixation using 4% PFA and overnight air-drying at RT after cryosectioning. Tissue morphology was preserved under these conditions. Conversely, tissues bleached in KMnO4/oxalic acid demonstrated poor depigmentation with extensive tissue damage. Warm dilute H2O2 at 65°C for 120 minutes rapidly and effectively bleached both cryo- and paraffin sections of murine and human ocular tissues.

Effect of radiation on the crystals of polyethylene and paraffins

International Nuclear Information System (INIS)

Ungar, G.; Grubb, D.T.; Keller, A.

1980-01-01

Paraffins were irradiated with electrons in the electron microscope. The electron microscopic image and the electron diffraction patterns were followed as a function of dose. The objectives were: (a) to establish a connection between the 'polyethylene-type' and 'paraffin-like' behaviour and (b) to identify the phase segregation, by visual means. Increasing chain length, increasing dose rate and decreasing temperature individually and in combination, were found to favour the 'polyethylene-type' behaviour (crystal destruction through increasing lattice defects) while the reverse trend of the above three variables favoured the 'paraffin-like' behaviour (phase-segregated damaged and undamaged species). Segregated phases could in some circumstances be identified as non-diffracting 'droplets' within a crystalline matrix, with the lattice hardly affected, in the electron microscopic image. These droplets remain constant in number but increase in size as the irradiation progresses, the number of droplets depending on the chain length of the paraffin, on the irradiation temperature and on the dose rate. This behaviour, together with some further observations, reveals that the radiation-induced active species do not form crosslinks in situ but migrate over distances which can amount to μm. In contrast to the above, in the case of the lowest paraffin investigated, (C 23 H 48 ), the lattice became uniformly distorted as judged from the diffraction pattern, but the damage was observed to 'heal-out' with time. The results are discussed. (author)

Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

Energy Technology Data Exchange (ETDEWEB)

Gartner, Hunter [School of Packaging, Michigan State University, East Lansing, Michigan (United States); Li, Yana [Mechanical Engineering College, Wuhan Polytechnic University (China); Almenar, Eva, E-mail: ealmenar@msu.edu [School of Packaging, Michigan State University, East Lansing, Michigan (United States)

2015-03-30

Graphical abstract: - Highlights: • Surface tension between PLA/CS blend solution and PLA film modified by MDI. • Better wettability between PLA/CS blend solution and PLA film by increasing MDI. • Increased breaking strength by increasing MDI due to the increased H-bonding. • Increased number of physical entanglements between PLA/CS coating and PLA film. • Development of a suitable bio-based multilayer film for food packaging applications. - Abstract: The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41–35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228–303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film.

Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

International Nuclear Information System (INIS)

Gartner, Hunter; Li, Yana; Almenar, Eva

2015-01-01

Graphical abstract: - Highlights: • Surface tension between PLA/CS blend solution and PLA film modified by MDI. • Better wettability between PLA/CS blend solution and PLA film by increasing MDI. • Increased breaking strength by increasing MDI due to the increased H-bonding. • Increased number of physical entanglements between PLA/CS coating and PLA film. • Development of a suitable bio-based multilayer film for food packaging applications. - Abstract: The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41–35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228–303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film

Properties of form-stable paraffin/silicon dioxide/expanded graphite phase change composites prepared by sol–gel method

International Nuclear Information System (INIS)

Li, Min; Wu, Zhishen; Tan, Jinmiao

2012-01-01

Highlights: ► Paraffin/SiO 2 /EG composite PCM was prepared with sol–gel method. ► The thermal conductivity of SiO 2 /paraffin/EG is 94.7% higher than paraffin. ► The latent heat of paraffin/SiO 2 /EG composite is 104.4 J/g. -- Abstract: A form-stable paraffin/silicon dioxide (SiO 2 )/expanded graphite (EG) composite phase change material (PCM) was prepared by sol–gel method. Silica gel acts as the supporting material and EG is used to increase the thermal conductivity. The mass fractions of silicon oxide and graphite are 20.8% and 7.2%, respectively. The composite PCM was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transformation infrared spectroscopy (FTIR) method. Thermal properties and thermal stability of the composite PCM were studied using differential scanning calorimetry (DSC). The result shows that paraffin was well dispersed in the network of silica gel and there is no chemical reaction between them. The phase change temperature of the paraffin/SiO 2 composite and the paraffin/SiO 2 /EG composite are 27.53 °C and 27.72 °C, respectively. The latent heat of the paraffin/SiO 2 composite and the paraffin/SiO 2 /EG composite are 112.8 J/g and 104.4 J/g, respectively. The thermal conductivity of the SiO 2 /paraffin composite and the SiO 2 /paraffin/EG composite are 28.2% and 94.7% higher than that of paraffin.

Selective formation of diamond-like carbon coating by surface catalyst patterning

DEFF Research Database (Denmark)

Palnichenko, A.V.; Mátéfi-Tempfli, M.; Mátéfi-Tempfli, Stefan

2004-01-01

The selective formation of diamond-like carbon coating by surface catalyst patterning was studied. DLC films was deposited using plasma enhanced chemical vapor deposition, filtered vacuum arc deposition, laser ablation, magnetron sputtering and ion-beam lithography methods. The DLC coatings were...

Nickel nanoparticles-chitosan composite coated cellulose filter paper: An efficient and easily recoverable dip-catalyst for pollutants degradation.

Science.gov (United States)

Kamal, Tahseen; Khan, Sher Bahadar; Asiri, Abdullah M

2016-11-01

In this report, we used cellulose filter paper (FP) as high surface area catalyst supporting green substrate for the synthesis of nickel (Ni) nanoparticles in thin chitosan (CS) coating layer and their easy separation was demonstrated for next use. In this work, FP was coated with a 1 wt% CS solution onto cellulose FP to prepare CS-FP as an economical and environment friendly host material. CS-FP was put into 0.2 M NiCl 2 aqueous solution for the adsorption of Ni 2+ ions by CS coating layer. The Ni 2+ adsorbed CS-FP was treated with 0.1 M NaBH 4 aqueous solution to convert the ions into nanoparticles. Thus, we achieved Ni nanoparticles-CS composite through water based in-situ preparation process. Successful Ni nanoparticles formations was assessed by FESEM and EDX analyses. FTIR used to track the interactions between nanoparticles and host material. Furthermore, we demonstrated that the nanocomposite displays an excellent catalytic activity and reusability in three reduction reactions of toxic compounds i.e. conversion of 4-nitrophenol to 4-aminophenol, 2-nitrophenol to 2-aminophenol, and methyl orange dye reduction by NaBH 4 . Such a fabrication process of Ni/CS-FP may be applicable for the immobilization of other metal nanoparticles onto FP for various applications in catalysis, sensing, and environmental sciences. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of Hf Additions to Pt Aluminide Bond Coats on EB-PVD TBC Life

Science.gov (United States)

Nesbitt, James; Nagaraj, Ben; Williams, Jeffrey

2000-01-01

Small Hf additions were incorporated into a Pt aluminide coating during chemical vapor deposition (CVD) on single crystal RENE N5 substrates. Standard yttria-stabilized zirconia top coats were subsequently deposited onto the coated substrates by electron beam-physical vapor deposition (EB-PVD). The coated substrates underwent accelerated thermal cycle testing in a furnace at a temperature in excess of 1121 C (2050 F) (45 minute hot exposure, 15 minute cool to approximately 121 C (250 F)) until the thermal barrier coating (TBC) failed by spallation. Incorporating Hf in the bond coat increased the TBC life by slightly more than three times that of a baseline coating without added Hf. Scanning electron microscopy of the spalled surfaces indicated that the presence of the Hf increased the adherence of the thermally grown alumina to the Pt aluminide bond coat. The presence of oxide pegs growing into the coating from the thermally grown alumina may also partially account for the improved TBC life by creating a near-surface layer with a graded coefficient of thermal expansion.

Effect of functional groups on thermal conductivity of graphene/paraffin nanocomposite

Energy Technology Data Exchange (ETDEWEB)

Zabihi, Zabiholah; Araghi, Houshang, E-mail: araghi@aut.ac.ir

2016-11-25

In this paper, thermal conductivity of graphene/paraffin nanocomposite using micromechanical model has been studied. The behavior of thermal conductivity of nanocomposite as a function of volume fraction of graphene is studied. Then is shown that as the interfacial thermal resistance at the graphene–paraffin interface decreases, the thermal conductivity of nanocomposite increases. In order to reduce the interfacial thermal resistance, functional groups in the interface between graphene and paraffin are used. It can be observed that using functional groups of hydrogen, methyl and phenyl in the interface of nanocomposite, contributes to the improvement of the thermal conductivity. Moreover, as the rate of coverage of the surface of graphene with functional groups of H, CH{sub 3} and C{sub 6}H{sub 5} increases, the thermal conductivity of nanocomposite improves. - Highlights: • Thermal conductivity nanocomposite exhibit nonlinear behavior with volume faction. • Phenyl is better to form the thermal conductivity network in paraffin. • The thickness of interfacial layer can be obtained 12.75 nm.

Observations of radiation damage effects in paraffin and polyethylene crystals

International Nuclear Information System (INIS)

Petermann, J.; Gleiter, H.; Bochum Univ.

1973-01-01

A report is given on electron microscopic observations on n-paraffin and polyethylene monocrystals after irradiating with electrons. The observations show that the cross-links in n-paraffin monocrystals form agglomerates which preferably occur in the neighbourhood of lattice defects. In polyethylene monocrystals, the cross-links line up in long rows parallel to the [100] or [010] direction. (orig./LH) [de

Stability analysis of SiO2/SiC multilayer coatings

International Nuclear Information System (INIS)

Fu Zhiqiang; Jean-Charles, R.

2006-01-01

The stability behaviours of SiC coatings and SiO 2 /SiC coatings in helium with little impurities are studied by HSC Chemistry 4.1, the software for analysis of Chemical reaction and equilibrium in multi-component complex system. It is found that in helium with a low partial pressure of oxidative impurities under different total pressure, the key influence factor controlling T cp of SiC depends is the partial pressure of oxidative impurities; T cp of SiC increases with the partial pressure of oxidative impurities. In helium with a low partial pressure of different impurities, the key influence factor of T cs of SiO 2 are both the partial pressure of impurities and the amount of impurities for l mol SiO 2 ; T cs of SiO 2 increases with the partial pressure of oxidative impurities at the same amount of the impurities for 1 mol SiO 2 while it decreases with the amount of the impurities for 1 mm SiO 2 at the same partial pressure of the impurities. The influence of other impurities on T cp of SiC in He-O 2 is studied and it is found that CO 2 , H 2 O and N-2 increase T cp of SiC in He-O 2 while H 2 , CO and CH 4 decrease T cp of SiC He-O 2 . When there exist both oxidative impurities and reductive impurities, their effect on T cs of SiO 2 can be suppressed by the other. In HTR-10 operation atmosphere, SiO 2 /SiC coatings can keep stable status at higher temperature than SiC coatings, so SiO 2 /SiC coatings is more suitable to improve the oxidation resistance of graphite in HTR-10 operation atmosphere compared with SiC coatings. (authors)

The adhesion of SiNx thin layers on silica-acrylate coated polymer substrates

NARCIS (Netherlands)

Abdallah, Amir; Lu, K.; Ovchinnikov, C.D.; Bulle-Lieuwma, C.W.T.; Bouten, P.C.P.; With, de G.

2009-01-01

Plasma Enhanced Chemical Vapor Deposition (PECVD) was used to grow 200, 300 and 400 nm thick silicon nitride layers (SiN x ) on a high temperature aromatic polyester substrate spin coated with a silica-acrylate hybrid coating (hard coat). Layers deposited without oxygen plasma treatment remained

High temperature oxidation behavior of hafnium modified NiAl bond coat in EB-PVD thermal barrier coating system

Energy Technology Data Exchange (ETDEWEB)

Guo Hongbo; Sun Lidong; Li Hefei [Department of Material Science and Engineering, Beijing University of Aeronautics and Astronautics, No.37 Xueyuan Road, Beijing 100083 (China); Gong Shengkai [Department of Material Science and Engineering, Beijing University of Aeronautics and Astronautics, No.37 Xueyuan Road, Beijing 100083 (China)], E-mail: gongsk@buaa.edu.cn

2008-06-30

NiAl coatings doped with 0.5 at.% and 1.5 at.% Hf were produced by co-evaporation of NiAl and Hf ingots by electron beam physical vapor deposition (EB-PVD), respectively. The addition of 0.5 at.% Hf significantly improved the cyclic oxidation resistance of the NiAl coating. The TGO layer in the 1.5 at.% Hf doped NiAl coating is straight; while that in the 0.5 at.% Hf doped coating became undulated after thermal cycling. The doped NiAl thermal barrier coatings (TBCs) revealed improved thermal cycling lifetimes at 1423 K, compared to the undoped TBC. Failure of the 0.5 at.% Hf doped TBC occurred by cracking at the interface between YSZ topcoat and bond coat, while the 1.5 at.% Hf doped TBC cracked at the interface between bond coat and substrate.

Formation mechanism of a silicon carbide coating for a reinforced carbon-carbon composite

Science.gov (United States)

Rogers, D. C.; Shuford, D. M.; Mueller, J. I.

1975-01-01

Results are presented for a study to determine the mechanisms involved in a high-temperature pack cementation process which provides a silicon carbide coating on a carbon-carbon composite. The process and materials used are physically and chemically analyzed. Possible reactions are evaluated using the results of these analytical data. The coating is believed to develop in two stages. The first is a liquid controlled phase process in which silicon carbide is formed due to reactions between molten silicon metal and the carbon. The second stage is a vapor transport controlled reaction in which silicon vapors react with the carbon. There is very little volume change associated with the coating process. The original thickness changes by less than 0.7%. This indicates that the coating process is one of reactive penetration. The coating thickness can be increased or decreased by varying the furnace cycle process time and/or temperature to provide a wide range of coating thicknesses.

The effects of normal paraffins mobilizers on irradiated polypropylene

International Nuclear Information System (INIS)

Chen Wenxiu; Gao Ling

1995-01-01

The n-paraffins blended with polypropylene (PP) as mobilizer had been investigated. The effectiveness of mobilizer (n-paraffins) on irradiated polypropylene is dependent on the molecular weight of mobilizer and its content on polypropylene. The n-docosame (n-C 22 ) possesses the best effectiveness of radiation tolerance on PP among the mobilizer paraffins: n-decane (n-C 10 ), n-hexadecane (n-C 16 ), n-docosane (n-C 22 ) and n-hexatriacontane (n-C 36 ). The 2% (w/w) content of a given mobilizer is the most effective at reducing the embrittlement of irradiated PP as evidenced by the elongation at break. The physical properties of polypropylene with mobilizers such as density, Young's modulus, the Fraction of free volume and the weight swelling ratio in p-xylene at room temperature were measured. Above phenomena are related with the constructive of blended PP and demonstrated by its physical properties

Comments on H- volume production in Cs-seeded ion sources. Appendix I

International Nuclear Information System (INIS)

Peterson, J.R.

1986-01-01

Considerable interest was generated at the IAEA Negative Ion Beam Workshop in Grenoble, France, in March, 1985, by a report from the Kurchatov Institute on the development of a 2-ampere steady-state H - ion source, in which the ions were volume-produced in a discharge in H 2 , seeded with Cs vapor. The mechanism primarily responsible for this remarkably high current from a volume production source was not yet understood, but it was tentatively presumed to involve the collisional energy transfer from electronically excited Cs 6p atoms into H 2 vibrations. In any case, it was apparently different from the surface-plasma interactions that have been assumed to control the H - production in the Dudnikov-Dimov type sources

Design and Testing of Digitally Manufactured Paraffin Acrylonitrile-Butadiene-Styrene Hybrid Rocket Motors

OpenAIRE

McCulley, Jonathan M.

2013-01-01

This research investigates the application of additive manufacturing techniques for fabricating hybrid rocket fuel grains composed of porous Acrylonitrile-butadiene-styrene impregnated with paraffin wax. The digitally manufactured ABS substrate provides mechanical support for the paraffin fuel material and serves as an additional fuel component. The embedded paraffin provides an enhanced fuel regression rate while having no detrimental effect on the thermodynamic burn properties of the fuel g...

Oxidation resistant coatings for ceramic matrix composite components

Energy Technology Data Exchange (ETDEWEB)

Vaubert, V.M.; Stinton, D.P. [Oak Ridge National Lab., TN (United States); Hirschfeld, D.A. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States). Dept. of Materials and Metallurgical Engineering

1998-11-01

Corrosion resistant Ca{sub 0.6}Mg{sub 0.4}Zr{sub 4}(PO{sub 4}){sub 6} (CMZP) and Ca{sub 0.5}Sr{sub 0.5}Zr{sub 4}(PO{sub 4}){sub 6} (CS-50) coatings for fiber-reinforced SiC-matrix composite heat exchanger tubes have been developed. Aqueous slurries of both oxides were prepared with high solids loading. One coating process consisted of dipping the samples in a slip. A tape casting process has also been created that produced relatively thin and dense coatings covering a large area. A processing technique was developed, utilizing a pre-sintering step, which produced coatings with minimal cracking.

Advances in the chemical vapor deposition (CVD) of Tantalum

DEFF Research Database (Denmark)

Mugabi, James Atwoki; Eriksen, Søren; Christensen, Erik

2014-01-01

The chemical stability of tantalum in hot acidic media has made it a key material in the protection of industrial equipment from corrosion under such conditions. The Chemical Vapor Deposition of tantalum to achieve such thin corrosion resistant coatings is one of the most widely mentioned examples...

Study of the hydro-isomerization of paraffins with 7 and 8 carbon atoms on bifunctional catalysts; Etude de l'hydroisomerisation des paraffines a 7 et 8 atomes de carbone sur catalyseurs bifonctionnels

Energy Technology Data Exchange (ETDEWEB)

Patrigeon, A.

2000-10-11

Due to the suppression of lead additives and the trend to decrease the aromatic and olefinic content in gasoline, the interest for new octane enhancement processes has increased, particularly for isomerization of C{sub 7} and C{sub 8} linear paraffins into higher octane number multi-branched paraffins. Up to the present day, no industrial bifunctional catalyst exists due to the high tendency of the paraffins to be cracked limiting the amount of multi-branched products. The aim of this work is to study the possibility of isomerizing linear C{sub 7} and C{sub 8} paraffins in two steps in order to increase the amount of formed multi-branched paraffins. The first step converts linear paraffins into mono-branched paraffins (that step is supposed to be the slowest one) carried out using one bifunctional catalyst. The second step converts the formed mono-branched paraffins into multi-branched paraffins using a second bifunctional catalyst. The aim is to determine the characteristics of the two catalysts. To study the first step, Pt/zeolite or Pt/meso-porous solid catalysts, with different acidities and porosities, were tested in n-heptane and n-octane hydro-conversion. The role of solid porosity on selectivities was clearly established. Molecular modelling was utilised to explain the observed selectivities. To study the second step, the 2-methyl-hexane and 2-methyl-heptane hydro-conversion on Pt/H-beta and Pt/H-Y was carried out. This lead to maximum multi-branched yields similar to those obtained with the n-heptane and n-octane hydro-conversion. That result shows that the two steps isomerization process is not necessarily required because no more multi-branched products are formed. A kinetic study on the n-heptane hydro-conversion was performed. The decomposition of isomerization and cracking reactions into elementary steps has shown the major role of the paraffins physio-sorption step in the zeolite pores. (author)

Understanding cracking failures of coatings: A fracture mechanics approach

Science.gov (United States)

Kim, Sung-Ryong

A fracture mechanics analysis of coating (paint) cracking was developed. A strain energy release rate (G(sub c)) expression due to the formation of a new crack in a coating was derived for bending and tension loadings in terms of the moduli, thicknesses, Poisson's ratios, load, residual strain, etc. Four-point bending and instrumented impact tests were used to determine the in-situ fracture toughness of coatings as functions of increasing baking (drying) time. The system used was a thin coating layer on a thick substrate layer. The substrates included steel, aluminum, polycarbonate, acrylonitrile-butadiene-styrene (ABS), and Noryl. The coatings included newly developed automotive paints. The four-point bending configuration promoted nice transversed multiple coating cracks on both steel and polymeric substrates. The crosslinked type automotive coatings on steel substrates showed big cracks without microcracks. When theoretical predictions for energy release rate were compared to experimental data for coating/steel substrate samples with multiple cracking, the agreement was good. Crosslinked type coatings on polymeric substrates showed more cracks than theory predicted and the G(sub c)'s were high. Solvent evaporation type coatings on polymeric substrates showed clean multiple cracking and the G(sub c)'s were higher than those obtained by tension analysis of tension experiments with the same substrates. All the polymeric samples showed surface embrittlement after long baking times using four-point bending tests. The most apparent surface embrittlement was observed in the acrylonitrile-butadiene-styrene (ABS) substrate system. The impact properties of coatings as a function of baking time were also investigated. These experiments were performed using an instrumented impact tester. There was a rapid decrease in G(sub c) at short baking times and convergence to a constant value at long baking times. The surface embrittlement conditions and an embrittlement toughness

Reinforced Carbon Carbon (RCC) oxidation resistant material samples - Baseline coated, and baseline coated with tetraethyl orthosilicate (TEOS) impregnation

Science.gov (United States)

Gantz, E. E.

1977-01-01

Reinforced carbon-carbon material specimens were machined from 19 and 33 ply flat panels which were fabricated and processed in accordance with the specifications and procedures accepted for the fabrication and processing of the leading edge structural subsystem (LESS) elements for the space shuttle orbiter. The specimens were then baseline coated and tetraethyl orthosilicate impregnated, as applicable, in accordance with the procedures and requirements of the appropriate LESS production specifications. Three heater bars were ATJ graphite silicon carbide coated with the Vought 'pack cementation' coating process, and three were stackpole grade 2020 graphite silicon carbide coated with the chemical vapor deposition process utilized by Vought in coating the LESS shell development program entry heater elements. Nondestructive test results are reported.

High paraffin Kumkol petroleum processing under fuel and lubricant petroleum scheme

International Nuclear Information System (INIS)

Nadirov, N.K.; Konaev, Eh.N.

1997-01-01

Technological opportunity of high paraffin Kumkol petroleum processing under the fuel and lubricant scheme with production of lubricant materials in short supply, combustible materials and technical paraffin is shown. Mini petroleum block putting into operation on Kumkol deposit is reasonable economically and raises profitableness of hydrocarbon raw material production. (author)

Alternative waste form development - low-temperature pyrolytic carbon coatings

International Nuclear Information System (INIS)

Oma, K.H.; Rusin, J.M.; Kidd, R.W.; Browning, M.F.

1981-01-01

Although several chemical vapor deposition (CVD) - coated waste forms have been successfully produced, some major disadvantages associated with the high-temperature fluidized-bed CVD coating process exist. To overcome these disadvantages, the Pacific Northwest Laboratory has initiated the development of a pyrolytic carbon CVD coating system to coat large waste-form particles at temperatures ranging from 400 to 500/degree/C. This relatively simple system has been used to coat kilogram quantities of simulated waste-glass marbles. Further development of this system could result in a viable process to coat bulk quantities of both glass and ceramic waste forms. This paper discusses various aspects of the development work, including coating techniques, parametric study, and coater equipment. 10 refs

Zeolitic imidazolate frameworks with optimized pore structure for olefin/paraffin-separation

Energy Technology Data Exchange (ETDEWEB)

Paula, C.; Boehme, U.; Hartmann, M. [Erlangen-Nuernberg Univ. (Germany). Erlangen Catalysis Resource Center

2013-11-01

In the chemical industry, the largest part of energy is spent on separation processes such as the separation of olefin/paraffin mixtures from steam cracker effluents by low-temperature rectification. A suitable alternative to this energy and cost intensive process is separation by selective adsorption with suitable microporous adsorbent. In this work, different ZIFs (Zeolitic Imidazolate Frameworks) have been explored with respect to their separation of olefins and paraffins. The studied materials (e.g. ZIF-8 (SOD-Topology), ZIF-71 (RHO-Topology)) were selected because of their low diameter of the largest pore entrance (0.29 to 4.2 nm) which is close to the kinetic diameter of the C{sub 2} to C{sub 4} olefins and paraffins under study. In contrast to other MOF- or zeolite-based adsorbents, in ZIF-8 and ZIF-71, the paraffin is preferentially adsorbed, which is evident from the single-component adsorption isotherms at different temperature. In the corresponding mixture breakthrough curves, the olefin breaks through first and the alkane even displaces the olefin from the pores. Thus, ZIF-8 and ZIF-71 are interesting candidates for the envisaged paraffin/olefin separation. Whether the observed separation behavior is due to the structural properties of the studied ZIFs or a consequence of peculiar chemical properties is subject to further studies. (orig.) (Published in summary form only)

Cellular localization of 2-[3H]deoxy-D-glucose from paraffin-embedded brains

International Nuclear Information System (INIS)

Durham, D.; Woolsey, T.A.; Kruger, L.

1981-01-01

Results of experiments in which regional neuronal activity is revealed by a 2-[ 3 H]deoxy-D-glucose ( 3 H-2-DG)-paraffin section-emulsion autoradiography method are described. The trigeminal pathway of freely behaving mice was activated differentially by selective patterns of whisker removal. One hour after injection of concentrated 3 H-2-DG, the animals were perfused systemically with a periodate/lysine/paraformaldehyde mixture the brains were embedded in paraffin, and serial sections were taken and coated with emulsion for autoradiography. Diffusion of the isotope out of the tissue was assessed visually and by liquid scintillation counting. While substantial loss of 3 H isotope into the embedding fluids (about 95%) was found, the scintillation counts and the autoradiograms showed good fixation of the isotope in situ, no evidence of isotope movement into the emulsion, and no gradients of diffusion in the sectioned material. Patterns of regional labeling were similar to those reported from brains prepared by conventional 2-[ 14 C]deoxy-D-glucose ( 14 C-2-DG) autoradiography; Trigeminal structures associated with the intact (stimulated) whiskers were labeled relatively heavily, indicating that label uptake is specific with respect to neuronal activity. In the cortex, the patterns of label corresponded directly and precisely to those barrels known to receive inputs from the intact whiskers. Distribution of silver grains in the cortex and in the brainstem was correlated directly with neuronal profiles. Clearly, this approach offers considerable technical advantages, in particular, the ease with which the histological material is prepared. The resolution of the autoradiograms and the quality of the histology are excellent

Micro- and nano-surface structures based on vapor-deposited polymers

Directory of Open Access Journals (Sweden)

Hsien-Yeh Chen

2017-07-01

Full Text Available Vapor-deposition processes and the resulting thin polymer films provide consistent coatings that decouple the underlying substrate surface properties and can be applied for surface modification regardless of the substrate material and geometry. Here, various ways to structure these vapor-deposited polymer thin films are described. Well-established and available photolithography and soft lithography techniques are widely performed for the creation of surface patterns and microstructures on coated substrates. However, because of the requirements for applying a photomask or an elastomeric stamp, these techniques are mostly limited to flat substrates. Attempts are also conducted to produce patterned structures on non-flat surfaces with various maskless methods such as light-directed patterning and direct-writing approaches. The limitations for patterning on non-flat surfaces are resolution and cost. With the requirement of chemical control and/or precise accessibility to the linkage with functional molecules, chemically and topographically defined interfaces have recently attracted considerable attention. The multifunctional, gradient, and/or synergistic activities of using such interfaces are also discussed. Finally, an emerging discovery of selective deposition of polymer coatings and the bottom-up patterning approach by using the selective deposition technology is demonstrated.

Effect of Chitosan Coating Treatments and Calcium Dips on Quality and Shelf-life of Strawberries

International Nuclear Information System (INIS)

Swailam, H.M.

2008-01-01

Strawberries are a highly perishable fruit and storage life may be less than a week. In these investigations strawberries were treated with one of the following treatments: I) 1 % calcium chloride dips (1 % CaCl 2 ), II) 2 % irradiated (150 kGy in the solid state) chitosan (CS) (2 % Irr. CS) and III) with a coating formulation containing 2 % Irr. CS + 1 % CaCl 2 . They were then stored at 6 degree C for up to 24 days. The effectiveness of the different treatments was assessed by evaluating the microbiological, physicochemical and sensory properties of strawberries during the storage period. Results indicated that no sign of strawberries decay were observed in the fruits treated with CS formulation containing 2 % Irr. CS + 1 % CaCl 2 up to 20 days, where 6.1 % wt loss was detected. This treatment slowed the ripening of strawberries as shown by their retention of firmness and delayed changes in their external colour anthocyanin. To a lesser extent titratable acidity and ph were also affected by coatings. This treatment decreased the initial log counts of total aerobic bacteria, mould and yeast, coliform and E. coli. After 20 days of cold storage, the log counts of these micro organisms were lower than the log count of uncoated strawberries. Thus, CS can be used as a natural antimicrobial coating on fresh strawberries to improve microbiological quality and extend shelf-life. CS formulation contains 2 % Irr. CS + 1 % CaCl 2 extended the shelf-life of strawberries to 20 days in cold storage at 6 degree C with acceptable appearance, firmness, flavour and colour, while uncoated strawberries only lasted for 4 days as a result of mould growth and loss of surface appearance

Carbide coated fibers in graphite-aluminum composites

Science.gov (United States)

Imprescia, R. J.; Levinson, L. S.; Reiswig, R. D.; Wallace, T. C.; Williams, J. M.

1975-01-01

The NASA-supported program at the Los Alamos Scientific Laboratory (LASL) to develop carbon fiber-aluminum matrix composites is described. Chemical vapor deposition (CVD) was used to uniformly deposit thin, smooth, continuous coats of TiC on the fibers of graphite tows. Wet chemical coating of fibers, followed by high-temperature treatment, was also used, but showed little promise as an alternative coating method. Strength measurements on CVD coated fiber tows showed that thin carbide coats can add to fiber strength. The ability of aluminum alloys to wet TiC was successfully demonstrated using TiC-coated graphite surfaces. Pressure-infiltration of TiC- and ZrC-coated fiber tows with aluminum alloys was only partially successful. Experiments were performed to evaluate the effectiveness of carbide coats on carbon as barriers to prevent reaction between alluminum alloys and carbon. Initial results indicate that composites of aluminum and carbide-coated graphite are stable for long periods of time at temperatures near the alloy solidus.

Formulation, Casting, and Evaluation of Paraffin-Based Solid Fuels Containing Energetic and Novel Additives for Hybrid Rockets

Science.gov (United States)

Larson, Daniel B.; Desain, John D.; Boyer, Eric; Wachs, Trevor; Kuo, Kenneth K.; Borduin, Russell; Koo, Joseph H.; Brady, Brian B.; Curtiss, Thomas J.; Story, George

2012-01-01

This investigation studied the inclusion of various additives to paraffin wax for use in a hybrid rocket motor. Some of the paraffin-based fuels were doped with various percentages of LiAlH4 (up to 10%). Addition of LiAlH4 at 10% was found to increase regression rates between 7 - 10% over baseline paraffin through tests in a gaseous oxygen hybrid rocket motor. Mass burn rates for paraffin grains with 10% LiAlH4 were also higher than those of the baseline paraffin. RDX was also cast into a paraffin sample via a novel casting process which involved dissolving RDX into dimethylformamide (DMF) solvent and then drawing a vacuum on the mixture of paraffin and RDX/DMF in order to evaporate out the DMF. It was found that although all DMF was removed, the process was not conducive to generating small RDX particles. The slow boiling generated an inhomogeneous mixture of paraffin and RDX. It is likely that superheating the DMF to cause rapid boiling would likely reduce RDX particle sizes. In addition to paraffin/LiAlH4 grains, multi-walled carbon nanotubes (MWNT) were cast in paraffin for testing in a hybrid rocket motor, and assorted samples containing a range of MWNT percentages in paraffin were imaged using SEM. The fuel samples showed good distribution of MWNT in the paraffin matrix, but the MWNT were often agglomerated, indicating that a change to the sonication and mixing processes were required to achieve better uniformity and debundled MWNT. Fuel grains with MWNT fuel grains had slightly lower regression rate, likely due to the increased thermal conductivity to the fuel subsurface, reducing the burning surface temperature.

Removal of mercury vapor from ambient air of dental clinics using an air cleaning system based on silver nanoparticles

Directory of Open Access Journals (Sweden)

Chiman Saeidi

2015-06-01

Full Text Available Background & objective: Mercury is a toxic and bio-accumulative pollutant that has adverse effects on environmental and human health. There have been a number of attempts to regulate mercury emissions tothe atmosphere. Silver nanoparticles are a number of materials that have highly potential to absorb mercury and formation of mercury amalgam.The aim of this study is removal of mercury vapors in the dental clinic using a n a ir cleaning system based on silver nanoparticles. Methods: In this study, silver nanoparticles coated on the bed of foam and chemical and structural properties were determined using a number of methods such as UV-VIS-NIR spectroscopy and Scanning Electron Microscope (SEM connected the X-ray Emission Spectroscopy Energy (EDS. The a ir cleaning system efficiency to remove of the mercury vapor in simulated conditions in the laboratory and real conditions in the dental clinicwere measured by Cold Vapor Atomic Absorption Spectroscopy (CVAAS. Results: The images of SEM, showed that average sizeof silver nanoparticles in colloidal solution was ∼ 30nm and distribution of silver nanoparticles coated on foam was good. EDS spectrum confirmed associated the presence of silver nanoparticles coated on foam. The significantly difference observed between the concentration of mercury vapor in the off state (9.43 ± 0.342 μg.m-3 and on state (0.51 ± 0.031μg.m-3 of the a ir cleaning system. The mercury vapor removal efficiencyof the a ir cleaning system was calculated 95%. Conclusion : The air cleaning system based on foam coated by silver nanoparticles, undertaken to provide the advantages such as use facilitating, highly efficient operational capacity and cost effective, have highly sufficiency to remove mercury vapor from dental clinics.

Effect of paraffin saturation in a crude oil on operation of a field

Energy Technology Data Exchange (ETDEWEB)

Trebin, G F; Kapyrin, Yu V

1968-11-01

Both theoretical and practical studies in recent years have shown that in planning operational procedures for an oil field, the paraffin saturation of the crude oil must be considered. If the crude oil is essentially saturated with paraffin at reservoir condition, then paraffin deposition can occur around the well and in the well. Temperature in the reservoir can be lowered by 2 mechanisms: (1) by injection of water below reservoir temperature, and (2) by expansion of produced gas and consequent cooling of the produced oil. Possible application of these principles to several Soviet oil fields is discussed. In the Uzen field, a preliminary investigation is under way to test the feasibility of heating the injection water to prevent paraffin deposition in the reservoir.

Surface biofunctionalization of three-dimensional porous poly(lactic acid) scaffold using chitosan/OGP coating for bone tissue engineering.

Science.gov (United States)

Zeng, Sen; Ye, Jianhua; Cui, Zhixiang; Si, Junhui; Wang, Qianting; Wang, Xiaofeng; Peng, Kaiping; Chen, Wenzhe

2017-08-01

As one of the stimulators on bone formation, osteogenic growth peptide (OGP) improves both proliferation and differentiation of the bone cells in vitro and in vivo. The aim of this work was the preparation of three dimensional porous poly(lactic acid) (PLA) scaffold with high porosity from PLA-dioxane-water ternary system with the use of vacuum-assisted solvent casting, phase separation, solvent extraction and particle leaching methods. Then, by surface coating of PLA scaffold with chitosan (CS)/OGP solution, biofunctionalization of PLA scaffold had been completed for application in bone regeneration. The effects of frozen temperature (-20, -50, -80°C) and PLA solution concentration (10, 12, 14wt%) on the microstructure, water absorption, porosity, hydrophilicity, mechanical properties, and biocompatibility of PLA and CS/OGP/PLA scaffold were investigated. Results showed that both PLA and CS/OGP/PLA scaffolds have an interconnected network structure and a porosity of up to 96.1% and 91.5%, respectively. The CS/OGP/PLA scaffold exhibited better hydrophilicity and mechanical properties than that of uncoated PLA scaffold. Moreover, the results of cell culture test showed that CS/OGP coating could stimulate the proliferation and growth of osteoblast cells on CS/OGP/PLA scaffold. These finding suggested that the surface biofunctionalization by CS/OGP coating layer could be an effective method on enhancing cell adhesion to synthetic polymer-based scaffolds in tissue engineering application and the developed porous CS/OGP/PLA scaffold should be considered as alternative biomaterials for bone regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

Plasma deposition of antimicrobial coating on organic polymer

Science.gov (United States)

Rżanek-Boroch, Zenobia; Dziadczyk, Paulina; Czajkowska, Danuta; Krawczyk, Krzysztof; Fabianowski, Wojciech

2013-02-01

Organic materials used for packing food products prevent the access of microorganisms or gases, like oxygen or water vapor. To prolong the stability of products, preservatives such as sulfur dioxide, sulfites, benzoates, nitrites and many other chemical compounds are used. To eliminate or limit the amount of preservatives added to food, so-called active packaging is sought for, which would limit the development of microorganisms. Such packaging can be achieved, among others, by plasma modification of a material to deposit on its surface substances inhibiting the growth of bacteria. In this work plasma modification was carried out in barrier discharge under atmospheric pressure. Sulfur dioxide or/and sodium oxide were used as the coating precursors. As a result of bacteriological studies it was found that sulfur containing coatings show a 16% inhibition of Salmonella bacteria growth and 8% inhibition of Staphylococcus aureus bacteria growth. Sodium containing coatings show worse (by 10%) inhibiting properties. Moreover, films with plasma deposited coatings show good sealing properties against water vapor. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.

Optical characterization of antirelaxation coatings

Science.gov (United States)

Tsvetkov, S.; Gateva, S.; Cartaleva, S.; Mariotti, E.; Nasyrov, K.

2018-03-01

Antirelaxation coatings (ARC) are used in optical cells containing alkali metal vapor to reduce the depolarization of alkali atoms after collisions with the cell walls. The long-lived ground state polarization is a basis for development of atomic clocks, magnetometers, quantum memory, slow light experiments, precision measurements of fundamental symmetries etc. In this work, a simple method for measuring the number of collisions of the alkali atoms with the cell walls without atomic spin randomization (Nasyrov et al., Proc. SPIE (2015)) was applied to characterize the AR properties of two PDMS coatings prepared from different solutions in ether (PDMS 2% and PDMS 5%). We observed influence of the light-induced atomic desorption (LIAD) on the AR properties of coatings.

Flow restrictor silicon membrane microvalve actuated by optically controlled paraffin phase transition

International Nuclear Information System (INIS)

Kolari, K; Havia, T; Stuns, I; Hjort, K

2014-01-01

Restrictor valves allow proportional control of fluid flow but are rarely integrated in microfluidic systems. In this study, an optically actuated silicon membrane restrictor microvalve is demonstrated. Its actuation is based on the phase transition of paraffin, using a paraffin wax mixed with a suitable concentration of optically absorbing nanographite particles. Backing up the membrane with oil (the melted paraffin) allows for a compliant yet strong contact to the valve seat, which enables handling of high pressures. At flow rates up to 30 µL min −1 and at a pressure of 2 bars, the valve can successfully be closed and control the flow level by restriction. The use of this paraffin composite as an adhesive layer sandwiched between the silicon valve and glass eases fabrication. This type of restrictor valve is best suited for high pressure, low volume flow silicon-based nanofluidic systems. (paper)

Enhancing Hybrid Perovskite Detectability in the Deep Ultraviolet Region with Down-Conversion Dual-Phase (CsPbBr3-Cs4PbBr6) Films.

Science.gov (United States)

Tong, Guoqing; Li, Huan; Zhu, Zhifeng; Zhang, Yan; Yu, Linwei; Xu, Jun; Jiang, Yang

2018-04-05

Hybrid perovskite photodetectors (PDs) exhibit outstanding performance in the ultraviolet-visible (UV-vis) spectrum but have poor detectability in the deep ultraviolet (DUV) region (200-350 nm). In this work, a novel inorganic-hybrid architecture that incorporates a dual-phase (CsPbBr 3 -Cs 4 PbBr 6 ) inorganic perovskite material as a down-conversion window layer and a hybrid perovskite as a light capture layer was prepared to achieve faster, highly sensitive photodetection in the DUV spectrum. A dual-phase inorganic perovskite film coated on the back surface of the photodetector enables strong light absorption and tunes the incident energy into emission bands that are optimized for the perovskite photodetector. The presence of Cs 4 PbBr 6 enhances the capture and down-conversion of the incident DUV light. Due to the down-conversion and transport of the DUV photons, a self-driven perovskite photodetector with this composite structure exhibits a fast response time of 7.8/33.6 μs and a high responsivity of 49.4 mA W -1 at 254 nm without extra power supply.

Endothelial disruptive proinflammatory effects of nicotine and e-cigarette vapor exposures.

Science.gov (United States)

Schweitzer, Kelly S; Chen, Steven X; Law, Sarah; Van Demark, Mary; Poirier, Christophe; Justice, Matthew J; Hubbard, Walter C; Kim, Elena S; Lai, Xianyin; Wang, Mu; Kranz, William D; Carroll, Clinton J; Ray, Bruce D; Bittman, Robert; Goodpaster, John; Petrache, Irina

2015-07-15

The increased use of inhaled nicotine via e-cigarettes has unknown risks to lung health. Having previously shown that cigarette smoke (CS) extract disrupts the lung microvasculature barrier function by endothelial cell activation and cytoskeletal rearrangement, we investigated the contribution of nicotine in CS or e-cigarettes (e-Cig) to lung endothelial injury. Primary lung microvascular endothelial cells were exposed to nicotine, e-Cig solution, or condensed e-Cig vapor (1-20 mM nicotine) or to nicotine-free CS extract or e-Cig solutions. Compared with nicotine-containing extract, nicotine free-CS extract (10-20%) caused significantly less endothelial permeability as measured with electric cell-substrate impedance sensing. Nicotine exposures triggered dose-dependent loss of endothelial barrier in cultured cell monolayers and rapidly increased lung inflammation and oxidative stress in mice. The endothelial barrier disruptive effects were associated with increased intracellular ceramides, p38 MAPK activation, and myosin light chain (MLC) phosphorylation, and was critically mediated by Rho-activated kinase via inhibition of MLC-phosphatase unit MYPT1. Although nicotine at sufficient concentrations to cause endothelial barrier loss did not trigger cell necrosis, it markedly inhibited cell proliferation. Augmentation of sphingosine-1-phosphate (S1P) signaling via S1P1 improved both endothelial cell proliferation and barrier function during nicotine exposures. Nicotine-independent effects of e-Cig solutions were noted, which may be attributable to acrolein, detected along with propylene glycol, glycerol, and nicotine by NMR, mass spectrometry, and gas chromatography, in both e-Cig solutions and vapor. These results suggest that soluble components of e-Cig, including nicotine, cause dose-dependent loss of lung endothelial barrier function, which is associated with oxidative stress and brisk inflammation.

Modified n-HA/PA66 scaffolds with chitosan coating for bone tissue engineering: cell stimulation and drug release.

Science.gov (United States)

Zou, Qin; Li, Junfeng; Niu, Lulu; Zuo, Yi; Li, Jidong; Li, Yubao

2017-09-01

The dipping-drying procedure and cross-linking method were used to make drug-loaded chitosan (CS) coating on nano-hydroxyapatite/polyamide66 (nHA/PA66) composite porous scaffold, endowing the scaffold controlled drug release functionality. The prefabricated scaffold was immersed into an aqueous drug/CS solution in a vacuum condition and then crosslinked by vanillin. The structure, porosity, composition, compressive strength, swelling ratio, drug release and cytocompatibility of the pristine and coating scaffolds were investigated. After coating, the scaffold porosity and pore interconnection were slightly decreased. Cytocompatibility performance was observed through an in vitro experiment based on cell attachment and the MTT assay by MG63 cells which revealed positive cell viability and increasing proliferation over the 11-day period in vitro. The drug could effectively release from the coated scaffold in a controlled fashion and the release rate was sustained for a long period and highly dependent on coating swelling, suggesting the possibility of a controlled drug release. Our results demonstrate that the scaffold with drug-loaded crosslinked CS coating can be used as a simple technique to render the surfaces of synthetic scaffolds active, thus enabling them to be a promising high performance biomaterial in bone tissue engineering.

Determination Of Adsorption And Paraffin Characterization Of Treatment To Adsorb Vegetable Oil

International Nuclear Information System (INIS)

Aminah, Neneng Siti; Mulijani, Sri; Sudirman; Ridwan

2004-01-01

Using vegetable oil repeatedly, beside affect on quality decline of food and the oil itself, it is harmful to human health. Some poisoning and carcinogenic symptom were founded with experiment using animals. According to that fact, the aim of the research is using paraffin and candle to adsorb used vegetable oil and to convert into solid sample, so it can be easily wasted. At first, 2 g of sample was poured into the heated oil, with gently stirrer until it turned cold and harden. Each sample and standard before and after treatment was characterized with Ftir, XRD, and DSc. The result shows that paraffins adsorbs 40 ml used vegetable oil with 2 g sample in proportion. That proportion is lower than the standard which can adsorb 66.67 ml vegetable oil in the same weight sample. The difference of paraffin and standard is caused by physical properties within that two materials, and it can be explained by Ftir, X-Ray Diffraction (XRD) and differential scanning calorimetry (DSc). Based on result of Ftir analysis, standard consented of saturated hydrocarbon compound (alkanes) whereas paraffin consisted of unsaturated hydrocarbon compound (alkenes). Infrared spectrum after treatment showed the changes of compound, O-H and esters group were formed and it shows characterised the adsorption process. The result of DSc analysis showed that crystalline the melting point of standard is 75,3 o C and paraffin is 54,17 o C. The result of analysis XRD, described that standard and paraffin before treatment are crystalline whereas after treatment are am orf

Chemical changes in the chloroform-paraffin system irradiated by 60Co gamma-rays, 1

International Nuclear Information System (INIS)

Yoshino, Tomio; Sakaue, Muneko; Shimizu, Yasuko; Kawamura, Fumio.

1979-01-01

It has been reported that the chloroform-paraffin-dye system have excellent sensitivity for radiation as a solid chemical dosimeter or a phantom. However, the chemical changes in the irradiated system are not examined in detail. In the present study, the effect of paraffin on changes in the above system of a liquid state irradiated by 60 Co γ-rays was examined by using various normal paraffin, and the other variable factors on the changes were done. When the chloroform solution and the solution containing 25 per cent of paraffin by volume with 5.0 x 15 -5 mol/liter of Methyl Yellow as a dye were irradiated by 2000 R, G values for the formation of hydrogen chloride in the both solutions were 8.4 and 10.8, respectively, and were little affected by the kind of those, from C 6 (hexane) to C 36 (hexatria-contane). These results suggest that chlorine radical formed by radiolysis of chloroform may react with hydrogen atom from paraffin, thereby increasing the amount of hydrogen chloride. Presence of oxygen increased G value of the chloroform solution from 7.6 to 8.4, but did little that of the solution containing paraffin. (author)

2-Mercaptobenzothiazole doped chitosan/11-alkanethiolate acid composite coating: Dual function for copper protection

International Nuclear Information System (INIS)

Bao Qi; Zhang Dun; Wan Yi

2011-01-01

Chitosan (CS) hydrogel loaded with the well-known corrosion inhibitor 2-mercaptobenzothiazole (MBT) has been introduced into a composite coating to improve copper protection. This composite coating, which has both anticorrosion and antibacterial properties, was fabricated onto the surface of copper by combining a simple self-assembled monolayer technique with a sol-gel method. The anti-corrosion ability of the coating in 3.5 wt.% NaCl solution was investigated by electrochemical methods including potentiodynamic polarization and electrochemical impedance spectroscopy. The protection efficiency of the coating is 97.70%, calculated on the basis of the corrosion current density. The stability and integrity of the composite coating were evaluated by field emission scanning electron microscopy (FESEM) and energy dispersive spectrometry (EDS). The FESEM and EDS results suggest that the composite coating endows the copper substrate with antibacterial properties, as untreated bare copper underwent microbiologically influenced corrosion in the presence of sulphate reducing bacteria (SRB). This antibacterial feature was further confirmed by the SRB culture method. In a 3.5% NaCl solution and highly corrosive SRB culture media, the as-prepared CS based composite coating gave corrosion protection by exhibiting better barrier effects against the attack of aggressive environments.

Thermal contact conductance of metallic coated BiCaSrCuO superconductor/copper interfaces at cryogenic temperatures

International Nuclear Information System (INIS)

Ochterbeck, J.M.; Peterson, G.P.; Fletcher, L.S.

1992-01-01

The effects of vapor deposited coatings on the thermal contact conductance of cold pressed, normal state BiCaSrCuO superconductor/oxygen-free copper interfaces were experimentally investigated over a pressure range of 200 to 2,000 kPa. Using traditional vapor deposition processes, thin coatings of indium or lead were applied to the superconductor material to determine the effect on the heat transfer occurring at the interface. The test data indicate that the contact conductance can be enhanced using these coatings, with indium providing the greater enhancement. The experimental program revealed the need for a better understanding and control of the vapor deposition process when using soft metallic coatings. Also, the temperature-dependent microhardness of copper was experimentally determined and found to increase by approximately 35 percent as the temperature decreased from 300 to 85 K. An empirical model was developed to predict the effect of soft coatings on the thermal contact conductance of the superconductor/copper interfaces. When applied, the model agreed well with the data obtained in this investigation at low coating thicknesses but overpredicted the data as the thickness increased. In addition, the model agreed very well with data obtained in a previous investigation for silvercoated nickel substrates at all coating thicknesses

Development of Y-BA-CU-O Coated Conductor Using Metal Organic Chemical Vapor Deposition

National Research Council Canada - National Science Library

Selvamanickam, V

2003-01-01

.... The program includes a study of the a) influence of MOCVD processing conditions such as the flow rate of precursor vapors, precursor vaporization temperatures, oxygen partial pressure, reactor pressure, and the deposition temperature...

Microstructural, mechanical and oxidation features of NiCoCrAlY coating produced by plasma activated EB-PVD

International Nuclear Information System (INIS)

He, Jian; Guo, Hongbo; Peng, Hui; Gong, Shengkai

2013-01-01

NiCoCrAlY coatings produced by electron beam-physical vapor deposition (EB-PVD) have been extensively used as the oxidation resistance coatings or suitable bond coats in thermal barrier coating (TBC) system. However, the inherent imperfections caused by EB-PVD process degrade the oxidation resistance of the coatings. In the present work, NiCoCrAlY coatings were creatively produced by plasma activated electron beam-physical vapor deposition (PA EB-PVD). The novel coatings showed a terraced substructure on the surface of each grain due to the increased energy of metal ions and enhanced mobility of adatoms. Also a strong (1 1 1) crystallographic texture of γ/γ′ grains was observed. The toughness of the coatings got remarkably improved compared with the coatings deposited by conventional EB-PVD and the oxidation behavior at 1373 K showed that the novel coatings had excellent oxidation resistance. The possible mechanism was finally discussed.

Coated kapok fiber for removal of spilled oil

International Nuclear Information System (INIS)

Wang, Jintao; Zheng, Yian; Wang, Aiqin

2013-01-01

Highlights: ► A low-cost and biodegradable oil absorbent based on kapok fiber was prepared. ► The polymer-coated kapok fiber showed higher oil sorption capacity. ► Coated kapok fiber can be reused and the absorbed oil can be easily recovered. ► Adsorption of oil is spontaneous and exothermic physisorption and chemisorption. -- Abstract: Based on raw kapok fiber, two kinds of oil absorbers with high sorption capacity were prepared by a facile solution–immersion process. The coated polymer with low surface energy and rough fiber surface play important role in the retention of oil. The as-prepared fiber can quickly absorb gasoline, diesel, soybean oil, and paraffin oil up to above 74.5%, 66.8%, 64.4% and 47.8% of oil sorption capacity of raw fiber, respectively. The absorbed oils can be easily recovered by a simple vacuum filtration and the recovered coated-fiber still can be used for several cycles without obvious loss in oil sorption capacity. The thermodynamic study indicates that the adsorption process is spontaneous and exothermic, with complex physisorption and chemisorption. The results suggest that the coated fiber can be used as a low-cost alternative for the removal of oil spilled on water surface

High Contrast Coherent Population Trapping Resonances in Cs Vapour Cells with a Simple-Architecture Laser System

International Nuclear Information System (INIS)

Liu, Xiaochi

2013-01-01

This thesis reports the development of a simple-architecture laser system resonant at 895 nm used for the detection of high-contrast coherent population trapping (CPT) resonances in Cs vapor cells. The laser system combines a distributed feedback-diode (DFB) laser, a pigtailed Mach-Zehnder intensity electro-optic modulator (EOM) driven at 4.596 GHz for the generation of optical sidebands frequency-split by 9.192 GHz and a Michelson delay-line system to produce a bi-chromatic optical field that alternates between right and left circular polarization. This polarization pumping scheme, first proposed by Happer's group in Princeton on K atoms, allows to optically pump a maximum number of Cs atoms into the 0-0 magnetic field insensitive clock transition. Advanced noise reduction techniques were implemented in order to stabilize the laser power, the optical carrier suppression at the output of the EOM and the DFB laser frequency. Using this system, we demonstrated the detection of CPT resonances with a contrast of 80% in cm-scale Cs vapor cells. This contrast was measured to be increased until a saturation effect with the laser power at the expense of the CPT line broadening. To circumvent this issue, we proposed with a simple setup Ramsey spectroscopy of CPT resonances in vapor cells to combine high-contrast and narrow line width of the CPT resonances. In this setup, the EOM is used both for optical sidebands generation and light switch to produce Ramsey interaction. Ramsey fringes of 166 Hz line width with a contrast better than 30% were detected with this setup. This laser system will be in a near future devoted to be used for the development of a high-performance CPT-based atomic clock. (author)

Corrosion protection of SiC-based ceramics with CVD mullite coatings

Energy Technology Data Exchange (ETDEWEB)

Auger, M.L.; Sarin, V.K. [Boston Univ., MA (United States). Dept. of Mfg. Engineering

1997-12-01

For the first time, crystalline mullite coatings have been chemically vapor deposited on SiC substrates to enhance its corrosion and oxidation resistance. Thermodynamic and kinetic considerations have been utilized to produce mullite coatings with a variety of growth rates, compositions, and morphologies. The flexibility of processing can be exploited to produce coated ceramics with properties tailored to specific applications and varied corrosive environments.

Numerical performance study of paraffin wax dispersed with alumina in a concentric pipe latent heat storage system

Directory of Open Access Journals (Sweden)

Valan Arasu Amirtham

2013-01-01

Full Text Available Latent heat energy storage systems using paraffin wax could have lower heat transfer rates during melting/freezing processes due to its inherent low thermal conductivity. The thermal conductivity of paraffin wax can be enhanced by employing high conductivity materials such as alumina (Al2O3. A numerical analysis has been carried out to study the performance enhancement of paraffin wax with nanoalumina (Al2O3 particles in comparison with simple paraffin wax in a concentric double pipe heat exchanger. Numerical analysis indicates that the charge-discharge rates of thermal energy can be greatly enhanced using paraffin wax with alumina as compared with a simple paraffin wax as PCM.

Chemical vapor deposition. Volume 2. 1975--July, 1978 (a bibliography with abstracts). Report for 1975--July 1978

International Nuclear Information System (INIS)

Smith, M.F.

1978-07-01

Research on chemical vapor deposition of carbon, carbides, ceramics, metals, and glasses are cited. Applications of this process include optical coatings, semiconducting films, laser materials, solar cells, composite fabrication, and nuclear reactor material fabrication. The physical, mechanical, and chemical properties of these coatings are covered

Ranking protective coatings: Laboratory vs. field experience

Science.gov (United States)

Conner, Jeffrey A.; Connor, William B.

1994-12-01

Environmentally protective coatings are used on a wide range of gas turbine components for survival in the harsh operating conditions of engines. A host of coatings are commercially available to protect hot-section components, ranging from simple aluminides to designer metallic overlays and ceramic thermal barrier coatings. A variety of coating-application processes are available, and they range from simple pack cementation processing to complex physical vapor deposition, which requires multimillion dollar facilities. Detailed databases are available for most coatings and coating/process combinations for a range of laboratory tests. Still, the analysis of components actually used in engines often yields surprises when compared against predicted coating behavior from laboratory testing. This paper highlights recent work to develop new laboratory tests that better simulate engine environments. Comparison of in-flight coating performance as well as industrial and factory engine testing on a range of hardware is presented along with laboratory predictions from standard testing and from recently developed cyclic burner-rig testing.

Physical Vapor Deposition of Thin Films

Science.gov (United States)

Mahan, John E.

2000-01-01

A unified treatment of the theories, data, and technologies underlying physical vapor deposition methods With electronic, optical, and magnetic coating technologies increasingly dominating manufacturing in the high-tech industries, there is a growing need for expertise in physical vapor deposition of thin films. This important new work provides researchers and engineers in this field with the information they need to tackle thin film processes in the real world. Presenting a cohesive, thoroughly developed treatment of both fundamental and applied topics, Physical Vapor Deposition of Thin Films incorporates many critical results from across the literature as it imparts a working knowledge of a variety of present-day techniques. Numerous worked examples, extensive references, and more than 100 illustrations and photographs accompany coverage of: * Thermal evaporation, sputtering, and pulsed laser deposition techniques * Key theories and phenomena, including the kinetic theory of gases, adsorption and condensation, high-vacuum pumping dynamics, and sputtering discharges * Trends in sputter yield data and a new simplified collisional model of sputter yield for pure element targets * Quantitative models for film deposition rate, thickness profiles, and thermalization of the sputtered beam

Plural coated article and process for making same

International Nuclear Information System (INIS)

Dickie, R.A.; Cassatta, J.C.

1977-01-01

A radiation polymerizable protective coating composition or paint, coated articles bearing such a protective radiation polymerizable paint, which on a non-polymerizable solvent, pigment, initiator and particulate fillerfree basis consists essentially of a binder solution of: (1) between about 90 and about 10 parts of a thermoplastic vinyl polymer free of olefinic unsaturation and prepared from at least about 85 weight percent of monofunctional vinyl monomers: (2) between about 10 and about 90 parts of vinyl solvent monomers for said vinyl polymer, at least about 10 weight percent, preferably at least about 30 weight percent, of said solvent monomers being selected from the group consisting of divinyl monomers, trivinyl monomers, tetravinyl monomers and mixtures thereof; and (3) between about 0.05 and about 1.0 parts per 100 parts of the total of said thermoplastic vinyl polymer and said vinyl solvent monomers of a mono- or diester of phosphoric acid bearing one or more sites of vinyl unsaturation. The composition exhibits excellent quality and good adhesion to a variety of substrated, in particular metals, including vapor deposited metals. Preferred articles bearing such a coating are prepared by: applying a base coat to a substrate and curing the same; vapor depositing a coating of a metal over the surface of the base coat; and applying to and curing on the surface of the base coat; and applying to and curing on the surface of the deposited metal the radiation polymerizable topcoat, preferably with little or no pigment contained therein

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)

Paraffin as oxygen vector modulates tyrosine phenol lyase production by Citrobacter freundii MTCC 2424.

Science.gov (United States)

Azmi, Wamik; Kumar, Ajay; Dev, Varun

2013-06-01

The efficiency of three oxygen-vectors liquid paraffin, silicone oil and n-dodecane in the production of tyrosine phenol lyase (TPL) by Citrobacter freundii MTCC 2424 was evaluated at 4% (v/v) concentration. The liquid paraffin as oxygenvectors was found to exhibit a stimulatory effect on TPL synthesis. The liquid paraffin at 6% (v/v) resulted in 34% increase in the TPL synthesis accompanied by a 13% increase in the production of cell mass at a 10 L scale. This improvement in TPL and cell mass production in the presence of liquid paraffin can be related to the fact that liquid paraffin was capable of maintaining dissolved O2 concentration above 28% throughout the course of the fermentation. Maintenance of the dissolved O2 concentration above 28% could be viewed in terms of an adequate oxygen supply to the rapidly dividing cells of the bacterium, which in turn resulted in enhanced synthesis of TPL and cell mass.

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

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.

Radiation polymerizable coating composition containing an unsaturated phosphoric ester

International Nuclear Information System (INIS)

Dickie, R.A.; Cassatta, J.C.

1976-01-01

A radiation polymerizable protective coating composition or paint consists essentially of a binder solution of: (1) between about 90 and about 10 parts of a saturated, thermoplastic vinyl polymer prepared from at least about 85 weight percent of monofunctional vinyl monomers; (2) between about 10 and about 90 parts of vinyl solvent monomers for the vinyl polymer, at least about 10 weight percent, preferably at least about 30 weight percent, of the solvent monomers being selected from the group consisting of divinyl monomers, trivinyl monomers, tetravinyl monomers and mixtures of these; and (3) between about 1.0 and about 15.0 parts per 100 parts of the total of the thermoplastic vinyl polymer and the vinyl solvent monomers of a triester of phosphoric acid bearing one or more sites of vinyl unsaturation. The composition exhibits excellent quality and good adhesion to a variety of substrates, in particular metals, including vapor deposited metals. Preferred articles bearing such a coating are prepared by applying a base coat to a substrate and curing the same; vapor depositing a coating of metal over the surface of the base coat; and applying to and curing on the surface of the deposited metal the radiation polymerizable topcoat, preferably with little or no pigment contained therein. 7 claims, no drawings

A nano-graphite/paraffin phase change material with high thermal conductivity

International Nuclear Information System (INIS)

Li, Min

2013-01-01

Highlights: ► Paraffin and NG formed a nanoscale compound. ► The thermal conductivity increased gradually with the content of NG. ► The thermal conductivity of the material containing 10% NG were 0.9362 W/m K. - Abstract: Nano-graphite (NG)/paraffin composites were prepared as composite phase change materials. NG has the function of improving the thermal conductivity of the composite. The microstructure and thermal properties of the materials were examined with environmental scanning electron microscopy and differential scanning calorimetry. The results indicated that the NG layers were randomly dispersed in the paraffin, and the thermal conductivity increased gradually with the content of NG. Thermal conductivity of the material containing 10% NG were 0.9362 W/m K

Thermal Cycling and High-Temperature Corrosion Tests of Rare Earth Silicate Environmental Barrier Coatings

Science.gov (United States)

Darthout, Émilien; Gitzhofer, François

2017-12-01

Lutetium and yttrium silicates, enriched with an additional secondary zirconia phase, environmental barrier coatings were synthesized by the solution precursor plasma spraying process on silicon carbide substrates. A custom-made oven was designed for thermal cycling and water vapor corrosion testing. The oven can test four specimens simultaneously and allows to evaluate environmental barrier performances under similar corrosion kinetics compared to turbine engines. Coatings structural evolution has been observed by SEM on the polished cross sections, and phase composition has been analyzed by XRD. All coatings have been thermally cycled between 1300 °C and the ambient temperature, without spallation, due to their porosity and the presence of additional secondary phase which increases the thermal cycling resistance. During water vapor exposure at 1200 °C, rare earth disilicates showed a good stability, which is contradictory with the literature, due to impurities—such as Si- and Al-hydroxides—in the water vapor jets. The presence of vertical cracks allowed the water vapor to reach the substrate and then to corrode it. It has been observed that thin vertical cracks induced some spallation after 24 h of corrosion.

Structure and corrosion properties of PVD Cr-N coatings

CERN Document Server

Liu, C; Ziegele, H; Leyland, A; Matthews, A

2002-01-01

PVD Cr-N coatings produced by physical vapor deposition (PVD) are increasingly used for mechanical and tribological applications in various industrial sectors. These coatings are particularly attractive for their excellent corrosion resistance, which further enhances the lifetime and service quality of coated components. PVD Cr-N coated steels in an aqueous solution are usually corroded by galvanic attack via through-coating 'permeable' defects (e.g., pores). Therefore, the corrosion performance of Cr-N coated steel is determined by a number of variables of the coating properties and corrosive environment. These variables include: (i) surface continuity and uniformity; (ii) through-coating porosity; (iii) film density and chemical stability; (iv) growth stresses; (v) interfacial and intermediate layers; (vi) coating thickness; (vii) coating composition; and (viii) substrate properties. In this article, PVD Cr-N coatings were prepared, by electron-beam PVD and sputter deposition, with different compositions, t...

Radiotherapic Valuation of Paraffin Wax for Patients with Oral Cancer

Energy Technology Data Exchange (ETDEWEB)

Na, Kyung Su; Seo, Seuk Jin; Lee, Je Hee; Yoo, Sook Heun [Dept. of Radiation Oncology, Seoul National University Hosdital, Seoul (Korea, Republic of)

2011-03-15

This study is designed to investigate radiotherapic valuation of Paraffin Wax, which is newly formed for this study and generally utilized in dentistry, and Mouth Piece and Putty impression, which are commonly used in radiotherapy, for oral cavity as a compensator. Each compensator was formed by 10 x 10 x 1 cm and measured radiation dose attenuation ratio with reference of water phantom which is made of tissue-equivalent materials. Two patients with oral cancer underwent DRR (Digitally Reconstructed Radiogrph) of Offline Review Program of Aria System and Portal vision for 5 times for each material to evaluate reproducibility by each filling materials. Moreover, MU (monitor unit) changes by dose absorption were considered in the case of inevitable implication of an filling materials in the range for radiotherapy. Radiation dose attenuation ratios were shown -0.7{approx}+3.7% for Mouth Piece, +0.21{approx}+0.39% for Paraffin Wax and -2.71{approx}-1.76% for Putty impression. Error ranges of reproducibility of positions were measured {+-}3 mm for Mouth Piece, {+-}2 mm for Paraffin Wax and {+-}2 mm for Putty impression. Difference of prescription MU from dose absorption with an filling material increased +7.8% (250 MU) in Putty impression and -0.9% (230 MU) in Paraffin Wax as converted into a percentage from the standard phantom, Water 232 MU. Dose reduction of boundary between cavity and tissue was observed for Mouth Piece. Mouth Piece also had low reproducibility of positions as it had no reflection of anatomy of oral cavity even though it was a proper material to separate Maxilla and Mandible during therapy. On the other hand, Putty impression was a suitable material to correctly re-position oral cavity as before. However, it risked normal tissues getting unnecessary over irradiation and it caused radiation dose decrease by -2.5% for 1cm volume in comparison of it of water phantom. Dose reduction in Paraffin Wax, Fat Tissue-Equivalent Material, was smaller than other

Mechanically stable antimicrobial chitosan-PVA-silver nanocomposite coatings deposited on titanium implants.

Science.gov (United States)

Mishra, Sandeep K; Ferreira, J M F; Kannan, S

2015-05-05

Bionanocomposite coatings with antimicrobial activity comprising polyvinyl alcohol (PVA)-capped silver nanoparticles embedded in chitosan (CS) matrix were developed by a green soft chemistry synthesis route. Colloidal sols of PVA-capped silver nanoparticles (AgNPs) were synthesized by microwave irradiating an aqueous solution comprising silver nitrate and PVA. The bionanocomposites were prepared by adding an aqueous solution of chitosan to the synthesized PVA-capped AgNPs sols in appropriate ratios. Uniform bionanocomposite coatings with different contents of PVA-capped AgNPs were deposited onto titanium substrates by "spread casting" followed by solvent evaporation. Nanoindentation and antimicrobial activity tests performed on CS and bionanocomposites revealed that the incorporation of PVA-capped AgNPs enhanced the overall functional properties of the coatings, namely their mechanical stability and bactericidal activity against Escherichia coli and Staphylococcus aureus. The coated specimens maintained their antimicrobial activity for 8h due to the slow sustained release of silver ions. The overall benefits for the relevant functional properties of the coatings were shown increase with increasing contents of PVA-capped AgNPs in the bionanocomposites. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Effect Used at Egg Preservation Using Paraffin and the Use of Sodium Bicarbonate on Physical, Chemical and Organoleptical Characteristcs of Egg Crackers

Directory of Open Access Journals (Sweden)

Zulfatunnisa Zulfatunnisa

2017-03-01

Full Text Available The materials used in this research were egg crackers made from albumen, tapioca, wheat flour, garlic, salt, water and sodium bicarbonate. The variables measured were expansion power, breaking force, water content, protein content, mineral content and organoleptic quality (colour, flavour, crispiness. Data were analized with analysis of variance and followed by Duncan's Multiple Range Test.The result showed that the preservation with paraffin and the use of sodium bicarbonate had a highly significant effect (P<0.01 on expansion power, breaking force, water content, protein content, minerals content and organoleptic quality (colour, flavour and crispiness. It's interaction had a highly significant effect (P<0.01 on protein content and organoleptic quality (flavour and crispiness of eggcrackers. It is found that egg coated with paraffin can be kept for 60 days had highfoaming foroe similar value with egg without preservation however, it haddisadvantages on expansion poweq breaking force and colour than fresh egg, so suggested to improve by use increase quantity albumen and decrease the Use of Sodium bicarbonate.

A novel combinatorial approach for the realization of advanced cBN composite coating

International Nuclear Information System (INIS)

Russell, W.C.; Yedave, S.N.; Sundaram, N.; Brown, W.D.; Malshe, A.P.

2001-01-01

The paper reports a novel coating process for the synthesis of hard material composite coatings. It consists of electrostatic spray coating (ESC) of powder particles (of micron-nanometer size) followed by chemical vapor infiltration (CVI) of a suitable binder phase. This novel approach enables fabrication of unique compositions such as cubic boron nitride (cBN) and titanium nitride (TiN) in a coating form. Recently, we have demonstrated the success of this technology by first coating a uniform over-layer (in excess of ∼ 10 μm) of cBN particles an carbide cutting tool inserts using ESC, followed by infiltration of particulate cBN matrix with TiN from its vapor phase using CVI to synthesize cBN-TiN a composite coating. The composite has shown excellent cBN-to-TiN and composite coating-to-carbide substrate adhesion. One of the main emphases of the paper is to discuss optimization and scale up of the ESC technology to achieve the desired microstructure and tailor the thickness across the cutting tool for better performance. Further, the cutting tools have been successfully tested for advanced machining applications. (author)

Investigation of rare chronic lipoid pneumonia associated with occupational exposure to paraffin aerosol.

Science.gov (United States)

Han, Chenghong; Liu, Lihai; Du, Shiping; Mei, Jianhua; Huang, Ling; Chen, Min; Lei, Yongliang; Qian, Junwen; Luo, Jianyong; Zhang, Meibian

2016-09-30

Occupational exposure to paraffin is an infrequent cause of lipoid pneumonia (LP) and related data are scare. We investigated the possible relationship between three rare cases of chronic LP and occupational exposure to paraffin aerosol in an iron foundry. The three cases of LP and their workplaces were investigated using data from field investigations, air monitoring, pulmonary radiological examinations, cell staining, and lung biopsies. The patients had long-term occupational exposure to paraffin. X-ray diffraction testing revealed that the raw material from the workshop was paraffin crystal. The air concentrations of paraffin aerosol in workplaces were significantly higher than outdoor background levels. Small diffuse and miliary shadows with unclear edges were observed throughout the whole lungs via radiography. Computed tomography revealed diffuse punctate nodules and a high density of stripe-like shadows in both lungs (ground-glass opacity in a lower lobe, and a mass-like lesion and high translucent area near the bottom of the lung). Lipid-laden macrophages were found in the sputum and bronchial lavage. A broadened alveolar septum and local focal fibrosis were also discovered via lung biopsy. The inflammatory reaction in the lung tissues appeared to resolve over time. These three rare cases of chronic LP in workers during molding and repair processes were associated with occupational paraffin aerosol exposure. Therefore, primary prevention is essential for molding or repairing workers in the iron foundry, and a differential diagnosis of occupational chronic LP (vs. pneumoconiosis) should be considered when treating these workers.

Influence of air exposure on CsI photocathodes

Energy Technology Data Exchange (ETDEWEB)

Xie, Yuguang, E-mail: ygxie@mail.ihep.ac.cn [State Key Laboratory of Particle Detection and Electronics, Institute of High Energy Physics, CAS and University of Science and Technology of China, Beijing 100049 (China); Zhang, Aiwu; Liu, Yingbiao [State Key Laboratory of Particle Detection and Electronics, Institute of High Energy Physics, CAS and University of Science and Technology of China, Beijing 100049 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Hongbang [Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Guangxi University, Naning 530004 (China); Hu, Tao; Zhou, Li; Cai, Xiao; Fang, Jian; Yu, Boxiang [State Key Laboratory of Particle Detection and Electronics, Institute of High Energy Physics, CAS and University of Science and Technology of China, Beijing 100049 (China); Ge, Yongshuai [State Key Laboratory of Particle Detection and Electronics, Institute of High Energy Physics, CAS and University of Science and Technology of China, Beijing 100049 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Lue, Qiwen [Shanxi University, Taiyuan 030006 (China); Sun, Xilei; Sun, Lijun; Xue, Zheng [State Key Laboratory of Particle Detection and Electronics, Institute of High Energy Physics, CAS and University of Science and Technology of China, Beijing 100049 (China); Xie, Yigang; Zheng, Yangheng [Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Lue, Junguang [State Key Laboratory of Particle Detection and Electronics, Institute of High Energy Physics, CAS and University of Science and Technology of China, Beijing 100049 (China)

2012-10-11

We investigate the influence of air exposure on the quantum efficiency (QE) and surface morphology of CsI photocathodes (PCs), at relative humidities (RH) higher than 80% down to nearly 3% (both at room temperature) and a 60 Degree-Sign C baking condition. By atomic force microscopy (AFM) surface analysis, it is clearly seen that RH >60% speeds up water film formation and CsI dissolution on the surface of the photocathode at the minute scale, while both grain size and QE change slowly at RH <30% at the hour scale. In the baking environment, the peak QE decreases less than 1.5% (absolute) within one week, and a stainless steel substrate and electron beam evaporation technique tend to effectively weaken the influence of air. With an Au-coated FR-4 substrate, the QE degradation is found to strongly depend on wavelength in the range of 120-210 nm. According to spectra of X-ray photoelectron spectroscopy (XPS), an excess of cesium was observed and the chemical reaction between water and CsI when exposed to humid air is proved. It is found that carbon, and not H{sub 2}O or O{sub 2}, is the main pollutant in the baking condition.

Ignition of Fuel Vapors Beneath Titanium Aircraft Skins Exposed to Lightning

Science.gov (United States)

Kosvic, T. C.; Helgeson, N. L.; Gerstein, M.

1971-01-01

Hot-spot and puncture ignition of fuel vapors by simulated lightning discharges was studied experimentally. The influences of skin coating, skin structure, discharge polarity, skin thickness, discharge current level, and current duration were measured and interpreted. Ignition thresholds are reported for titanium alloy constructed as sheets, sheets coated with sealants, and sandwich skins. Results indicated that the ignition threshold charge transfer for coated sheets, honeycomb, and truss skins is respectively about 200%, 400%, 800% that of bare alloy sheet of .102 cm (.040 in.)-thickness. It was found that hot-spot ignition can occur well after termination of the arc, and that sandwich materials allow ignition only if punctured.

Study on the effect of deposition rate and concentration of Eu on the fluorescent lifetime of CsI: Tl thin film

Energy Technology Data Exchange (ETDEWEB)

Xie, Yijun; Guo, Lina [University of Electronic Science and Technology of China, State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, Chengdu 610054 (China); Liu, Shuang, E-mail: shuangliu@uestc.edu.cn [University of Electronic Science and Technology of China, State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, Chengdu 610054 (China); Wang, Qianfeng; Zhang, Shangjian; Liu, Yong [University of Electronic Science and Technology of China, State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, Chengdu 610054 (China); Zhong, Zhiyong [University of Electronic Science and Technology of China, State Key Laboratory of Electronic Thin Films and Integrated Devices, Chengdu 610054 (China)

2017-06-21

Although there are many new scintillators being developed recently, CsI: Tl is still very efficient among them. The fluorescent lifetime is a very important parameter of CsI: Tl thin film and two series of experiments have been conducted to learn about it. Our experiments, however, have demonstrated that the deposition rate and the codoping of Eu{sup 2+} will significantly influence its fluorescent lifetime. In order to increase the efficiency of the imaging system, we intend to obtain a higher fluorescent lifetime for CsI: Tl thin film by controlling these two conditions. - Highlights: • We used vacuum vapor deposition method to grow the high-quality thin films. • The relationship between the deposition rate and the fluorescent lifetime of CsI: Tl thin film was tested. • Concentration of Eu on fluorescent lifetime of the CsI: Tl thin film was studied.

Magnetic orientation of paraffin in a magnetic levitation furnace

Science.gov (United States)

Takahashi, K.; Umeki, C.; Mogi, I.; Koyama, K.; Awaji, S.; Motokawa, M.; Watanabe, K.

2004-04-01

Containerless melting of paraffin under a magnetic levitation condition has been performed by using a cryogen-free hybrid magnet and two kinds of laser furnaces. One is local irradiation of CO 2 laser light at the top of the sample. The other is homogeneous irradiation of YAG laser light with a concave ring mirror. In the latter case, reduction of the Marangoni convection on the surface of the sample and the magnetic orientation of paraffin molecules were observed. The magnetic anisotropy of the spherical sample was confirmed by the measurement of magnetization and X-ray diffraction.

Magnetic orientation of paraffin in a magnetic levitation furnace

Energy Technology Data Exchange (ETDEWEB)

Takahashi, K.; Umeki, C.; Mogi, I.; Koyama, K.; Awaji, S.; Motokawa, M.; Watanabe, K

2004-04-30

Containerless melting of paraffin under a magnetic levitation condition has been performed by using a cryogen-free hybrid magnet and two kinds of laser furnaces. One is local irradiation of CO{sub 2} laser light at the top of the sample. The other is homogeneous irradiation of YAG laser light with a concave ring mirror. In the latter case, reduction of the Marangoni convection on the surface of the sample and the magnetic orientation of paraffin molecules were observed. The magnetic anisotropy of the spherical sample was confirmed by the measurement of magnetization and X-ray diffraction.

Magnetic orientation of paraffin in a magnetic levitation furnace

International Nuclear Information System (INIS)

Takahashi, K.; Umeki, C.; Mogi, I.; Koyama, K.; Awaji, S.; Motokawa, M.; Watanabe, K.

2004-01-01

Containerless melting of paraffin under a magnetic levitation condition has been performed by using a cryogen-free hybrid magnet and two kinds of laser furnaces. One is local irradiation of CO 2 laser light at the top of the sample. The other is homogeneous irradiation of YAG laser light with a concave ring mirror. In the latter case, reduction of the Marangoni convection on the surface of the sample and the magnetic orientation of paraffin molecules were observed. The magnetic anisotropy of the spherical sample was confirmed by the measurement of magnetization and X-ray diffraction

Spectral distribution measurements of neutrons in paraffin borax mixtures

International Nuclear Information System (INIS)

El-Khatib, A.M.; Gaber, M.; Abou El-Khier, M.A.

1987-01-01

Neutron fluxes from a compact D-T neutron source has been measured in paraffin-borax mixtures by using activation foil detectors with successive threshold energies. The absorbed doses, backscattering coefficients and build-up factors were determined as well. The contribution of thermal and intermediate neutron dose is much lower, compared to that of fast neutrons. Among the used mediums, paraffin loaded with 4% borax concentration was found to be the best absorbing medium against neutrons at near depths within the blocks, while at a depth around 12 cm the neutron absorption (or scattering) is independent on the type of the used medium. (author)

Improved cell for water-vapor electrolysis

Science.gov (United States)

Aylward, J. R.

1981-01-01

Continuous-flow electrolytic cells decompose water vapor in steam and room air into hydrogen and oxygen. Sintered iridium oxide catalytic anode coating yields dissociation rates hundredfold greater than those obtained using platinum black. Cell consists of two mirror-image cells, with dual cathode sandwiched between two anodes. Gas traverses serpentine channels within cell and is dissociated at anode. Oxygen mingles with gas stream, while hydrogen migrates through porous matrix and is liberated as gas at cathode.

Parylene C coating for high-performance replica molding.

Science.gov (United States)

Heyries, Kevin A; Hansen, Carl L

2011-12-07

This paper presents an improvement to the soft lithography fabrication process that uses chemical vapor deposition of poly(chloro-p-xylylene) (parylene C) to protect microfabricated masters and to improve the release of polymer devices following replica molding. Chemical vapor deposition creates nanometre thick conformal coatings of parylene C on silicon wafers having arrays of 30 μm high SU8 pillars with densities ranging from 278 to 10,040 features per mm(2) and aspect ratios (height : width) from 1 : 1 to 6 : 1. A single coating of parylene C was sufficient to permanently promote poly(dimethyl)siloxane (PDMS) mold release and to protect masters for an indefinite number of molding cycles. We also show that the improved release properties of parylene treated masters allow for fabrication with hard polymers, such as poly(urethane), that would otherwise not be compatible with SU8 on silicon masters. Parylene C provides a robust and high performance mold release coating for soft lithography microfabrication that extends the life of microfabricated masters and improves the achievable density and aspect ratio of replicated features.

Study on the bonding strength between calcium phosphate/chitosan composite coatings and a Mg alloy substrate

Science.gov (United States)

Zhang, Jie; Dai, Chang-Song; Wei, Jie; Wen, Zhao-Hui

2012-11-01

In order to improve the bonding strength between calcium phosphate/chitosan composite coatings and a micro-arc oxidized (MAO)-AZ91D Mg alloy, different influencing parameters were investigated in the process of electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). Surface morphology and phase constituents of the as-prepared materials were investigated by using X-ray diffractometer (XRD), Fourier-transformed infrared spectrophotometer (FTIR), Raman spectrometer, scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), and a thermo gravimetric and differential thermal analyzer (TG-DTA). Scratch tests were carried out to study the bonding properties between the coatings and the substrates. In vitro immersion tests were conducted to determine the corrosion behaviors of samples with and without deposit layers through electrochemical experiments. In the EPD process, the acetic acid content in the electrophoresis suspension and the electrophoretic voltage played important roles in improving the bonding properties, while the contents of chitosan (CS) and nano-hydroxyapatite (nHA, Ca10(PO4)6(OH)2) in the suspension had less significant influences on the mechanical bonding strength. It was observed that the coatings showed the excellent bonding property when an electrophoretic voltage was in a range of 40-110 V with other reagent amounts as follows: acetic acid: 4.5 vol.%, CS ≤ 0.25 g, nHA ≤ 2.0 g in 200 ml of a CS-acetic acid aqueous solution and nHA ≤ 2.5 g in 300 ml of absolute ethanol. The morphology of the composite coating obtained under the above optimal condition had a flake-like crystal structure. The EPD in the nHA/CS-acetic acid/ethanol suspension resulted in hydroxyapatite, chitosan, brushite (DCPD, CaHPO4·2H2O) and Ca(OH)2 in the coatings. After the as-prepared coating materials were immersed into PBS, Ca(OH)2 could be converted into HA and DCPD. The results of the electrochemical tests

High-temperature protective coatings for C/SiC composites

Directory of Open Access Journals (Sweden)

Xiang Yang

2014-12-01

Full Text Available Carbon fiber-reinforced silicon carbide (C/SiC composites were well-established light weight materials combining high specific strength and damage tolerance. For high-temperature applications, protective coatings had to provide oxidation and corrosion resistance. The literature data introduced various technologies and materials, which were suitable for the application of coatings. Coating procedures and conditions, materials design limitations related to the reactivity of the components of C/SiC composites, new approaches and coating systems to the selection of protective coatings materials were examined. The focus of future work was on optimization by further multilayer coating systems and the anti-oxidation ability of C/SiC composites at temperatures up to 2073 K or higher in water vapor.

The use of paraffin wax in a new solar cooker with inner and outer reflectors

Directory of Open Access Journals (Sweden)

Arabacigil Bihter

2015-01-01

Full Text Available In this paper, the potential use and effectiveness of paraffin wax in a new solar cooker was experimentally investigated during daylight and late evening hours. For these experiments, a cooker having an inner reflecting surface was designed, constructed by filling paraffin wax and metal shavings. The side- and sub-surface temperatures of the paraffin wax in the cooker are measured in the summer months of June and July. The thermal efficiency of the cooker was tested on different conditions. The results show that the optimum angle of the outer reflector is 30°. Here, the peak temperature of the paraffin wax in the solar cooker was 83.4 °C. The average solar radiation reflected makes a contribution of 9.26% to the temperature of paraffin wax with the outer reflector. The solar cooker with the outer reflector angle of 30° receives also reflected radiation from the inner reflectors. Besides, the heating time is decreased to approximately 1 hour. The designed solar cooker can be effectively used with 30.3% daily thermal efficiency and paraffin wax due to the amount of energy stored.

Synthesis, characterization and microwave absorption of carbon-coated Cu nanocapsules

Energy Technology Data Exchange (ETDEWEB)

Sun, Yuping [Center for Engineering Practice and Innovation Education, Anhui University of Technology, Maanshan, (China); Feng, Chao; Liu, Xianguo; Jin, Chuangui, E-mail: liuxianguohugh@gmail.com [School of Materials Science and Engineering, Anhui University of Technology, Maanshan (China); Or, Siu Wing [Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, (Hong Kong)

2014-03-15

The microstructure and microwave absorption of carbon-coated Cu nanocapsules have been investigated. Carbon-coated Cu nanocapsules have been synthesized by an arc-discharge method. The paraffin-Cu/C nanocapsules composite shows excellent electromagnetic (EM) absorption properties. An optimal reflection loss (RL) value of –40.0 dB is reached at 10.52 GHz for a layer 1.9 mm thickness. RL exceeding –20 dB can be realized in any interval within the 1-18 GHz range by choosing an appropriate thickness of the absorbent layer between 1.1 and 10.0 mm. Theoretical simulation for the microwave absorption using the transmission line theory agrees reasonably well with the experimental results. The EM-wave absorption properties of nanocapsules materials are illustrated by means of an absorption-tube-map. The carbon-coated Cu nano capsule is an attractive candidate for EM-wave absorption, which significantly enriches the family of EM-wave nano absorbents. (author)

Evaluation of performance loss of paraffin oil loaded filtering facepieces.

Science.gov (United States)

Tombolini, Francesca; Listrani, Stefano; Campopiano, Antonella; Plebani, Carmela

2016-01-01

Penetration measurements through commercially available filtering facepieces were performed with monodisperse DEHS aerosols ranging from 0.03 μm to 0.40 μm (either singly charged or neutralized), before and after 500 mg of paraffin oil loading. The distinct behavior of Coulomb and polarization capture efficiency is studied: as in the case of non loading also in the case of loading 500 mg of paraffin oil, the electrostatic capture mechanisms are mainly due to the Coulomb contribution up to aerosol particle diameter of about 0.10 μm, just when the polarization contribution becomes substantial. Both Coulomb and polarization capture mechanisms are influenced by the presence of 500 mg of paraffin oil, resulting less effective than the oil unloaded case of about 12% and 11%, respectively. By the occupational hygiene point of view, there is a degradation in the filter performance due to oil loading that the user does not realize because there is no remarkable variation in the breathing resistance.

Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

International Nuclear Information System (INIS)

Sun, Zhiming; Zhang, Yuzhong; Zheng, Shuilin; Park, Yuri; Frost, Ray L.

2013-01-01

Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value

Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhiming [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Zhang, Yuzhong [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Zheng, Shuilin, E-mail: shuilinzh@yahoo.com.cn [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Park, Yuri [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Frost, Ray L., E-mail: r.frost@qut.edu.au [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia)

2013-04-20

Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value.

Effect of boron nitride coating on fiber-matrix interactions

International Nuclear Information System (INIS)

Singh, R.N.; Brun, M.K.

1987-01-01

Coatings can modify fiber-matrix reactions and consequently interfacial bond strengths. Commercially available mullite, silicon carbide, and carbon fibers were coated with boron nitride via low pressure chemical vapor deposition and incorporated into a mullite matrix by hot-pressing. The influence of fiber-matrix interactions for uncoated fibers on fracture morphologies was studied. These observations are related to the measured values of interfacial shear strengths

Studies of the interaction of CS@ZnS:Mn with bovine serum albumin under illumination

Energy Technology Data Exchange (ETDEWEB)

Liu, Li, E-mail: 2476625723@qq.com [Institute of Agricultural Quality Standards and Testing Technology Research, Hubei Academy of Agricultural Science, Wuhan 430064 (China); Xiao, Ling [School of Resource and Environmental Science, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430072 (China)

2015-09-15

Highlights: • The interaction and illumination damages of CS@ZnS:Mn D-dots to BSA were studied. • The quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. • The hydrophobic interaction plays a major role; the binding processes are spontaneous. • The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was observed. • The probable mechanism is mainly a photo-induced free radical procedure. - Abstract: In this study, chitosan coated Mn-doped ZnS quantum dots (CS@ZnS:Mn D-dots) were obtained in aqueous media under ambient pressure. The interaction and illumination damages of CS@ZnS:Mn D-dots with bovine serum albumin (BSA) were studied by means of ultraviolet–visible (UV–vis) and fluorescence (FL) spectra. It was found that the FL of BSA was quenched by CS@ZnS:Mn D-dots. The dominating quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. Hydrophobic interaction plays a major role in the CS@ZnS:Mn–BSA interaction; binding processes are spontaneous. Influencing factors such as illumination time and CS@ZnS:Mn D-dots concentrations were considered. The FL quenching effect of BSA by CS@ZnS:Mn D-dots is enhanced with the increase of illumination time and CS@ZnS:Mn D-dots concentration. The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was also observed. It was proved that, the interaction of CS@ZnS:Mn D-dots with BSA under UV illumination is mainly a result of a photo-induced free radical procedure. CS@ZnS:Mn D-dots may be used as photosensitizers in photodynamic therapy.

Studies of the interaction of CS@ZnS:Mn with bovine serum albumin under illumination

International Nuclear Information System (INIS)

Liu, Li; Xiao, Ling

2015-01-01

Highlights: • The interaction and illumination damages of CS@ZnS:Mn D-dots to BSA were studied. • The quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. • The hydrophobic interaction plays a major role; the binding processes are spontaneous. • The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was observed. • The probable mechanism is mainly a photo-induced free radical procedure. - Abstract: In this study, chitosan coated Mn-doped ZnS quantum dots (CS@ZnS:Mn D-dots) were obtained in aqueous media under ambient pressure. The interaction and illumination damages of CS@ZnS:Mn D-dots with bovine serum albumin (BSA) were studied by means of ultraviolet–visible (UV–vis) and fluorescence (FL) spectra. It was found that the FL of BSA was quenched by CS@ZnS:Mn D-dots. The dominating quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. Hydrophobic interaction plays a major role in the CS@ZnS:Mn–BSA interaction; binding processes are spontaneous. Influencing factors such as illumination time and CS@ZnS:Mn D-dots concentrations were considered. The FL quenching effect of BSA by CS@ZnS:Mn D-dots is enhanced with the increase of illumination time and CS@ZnS:Mn D-dots concentration. The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was also observed. It was proved that, the interaction of CS@ZnS:Mn D-dots with BSA under UV illumination is mainly a result of a photo-induced free radical procedure. CS@ZnS:Mn D-dots may be used as photosensitizers in photodynamic therapy

The Effects of Oxidation-Induced Failures on Thermal Barrier Coatings with Platinum Aluminide and NiCoCrAlY Bond Coats

National Research Council Canada - National Science Library

Yanar, N

2001-01-01

...) deposited via electron beam vapor deposition (EBPVD). This TBC was deposited on both platinum aluminide and NiCoCrA1Y bond coats which in turn were deposited on superalloy substrates of Rare N5...

Growth, microstructure, and field-emission properties of synthesized diamond film on adamantane-coated silicon substrate by microwave plasma chemical vapor deposition

International Nuclear Information System (INIS)

Tiwari, Rajanish N.; Chang Li

2010-01-01

Diamond nucleation on unscratched Si surface is great importance for its growth, and detailed understanding of this process is therefore desired for many applications. The pretreatment of the substrate surface may influence the initial growth period. In this study, diamond films have been synthesized on adamantane-coated crystalline silicon {100} substrate by microwave plasma chemical vapor deposition from a gaseous mixture of methane and hydrogen gases without the application of a bias voltage to the substrates. Prior to adamantane coating, the Si substrates were not pretreated such as abraded/scratched. The substrate temperature was ∼530 deg. C during diamond deposition. The deposited films are characterized by scanning electron microscopy, Raman spectrometry, x-ray diffraction, and x-ray photoelectron spectroscopy. These measurements provide definitive evidence for high-crystalline quality diamond film, which is synthesized on a SiC rather than clean Si substrate. Characterization through atomic force microscope allows establishing fine quality criteria of the film according to the grain size of nanodiamond along with SiC. The diamond films exhibit a low-threshold (55 V/μm) and high current-density (1.6 mA/cm 2 ) field-emission (FE) display. The possible mechanism of formation of diamond films and their FE properties have been demonstrated.

The Insulation of Copper Wire by the Electrostatic Coating Process.

Science.gov (United States)

1983-06-30

Caster full production lines produce more uniform coating thicknesses. -18- U AM NC. IO C FWIO~k TX3M ..... ....... Z . A A I~ ~ 15X 7-., r - ’ r 15X... modification to meet specific usage requirements. t * -68- 482 5 APPENDIX CLIQUINITE’ COATING PRODU(:TS LIQUINITEE-COATING POWDERS FEP (Fluorinated Ethylene...Loss from Dissipation Factor (60 Hz-2xl0 9Hz) 0.2-1.2001 Revolving Disc, mg (60 Hz -2 x iO0 Hz) *CS 17 Wheel . 100 cycles 2.2 Surface Resistivity (250

Method of removing paraffin from mineral oils, shale oils, tar oils, and their fractions or residues

Energy Technology Data Exchange (ETDEWEB)

Palmquist, F T.E.

1949-09-08

A method is described for removing paraffin from mineral oils, shale oils, tar oils, and their fractions or residues by centrifuging in the presence of oil-dissolving and paraffin-precipitating solvents, by which the precipitated paraffin is made to pass through an indifferent auxiliary liquid, in which a removal of oil takes place, characterized in that as auxiliary liquid is used a liquid or mixture of liquids whose surface tension against the oil solution is sufficiently low for the paraffin to pass the layer of auxiliary liquid in the form of separate crystals.

Thin layer chitosan-coated cellulose filter paper as substrate for immobilization of catalytic cobalt nanoparticles.

Science.gov (United States)

Kamal, Tahseen; Khan, Sher Bahadar; Haider, Sajjad; Alghamdi, Yousef Gamaan; Asiri, Abdullah M

2017-11-01

A facile approach utilizing synthesis of cobalt nanoparticles in green polymers of chitosan (CS) coating layer on high surface area cellulose microfibers of filter paper (CFP) is described for the catalytic reduction of nitrophenol and an organic dye using NaBH 4 . Simple steps of CFP coating with 1wt% CS aqueous solution followed by Co 2+ ions adsorption from 0.2M CoCl 2 aqueous solution were carried out to prepare pre-catalytic strips. The Co 2+ loaded pre-catalytic strips of CS-CFP were treated with 0.19M NaBH 4 aqueous solution to convert the ions into nanoparticles. Successful Co nanoparticles formation was assessed by various characterization techniques of FESEM, EDX and XRD analyzes. TGA analyses were carried out on CFP, CS-CFP, and Co-CS-CFP for the determination of the amount of Co particles formed on the CS-FP, and to track their thermal properties. Furthermore, we demonstrated that the Co-CS-CFP showed an excellent catalytic activity and reusability in the reduction reactions a nitroaromatic compound of 2,6-dintirophenol (2,6-DNP) and brilliant cresyl blue (BCB) dye by NaBH 4 . The Co-CS-CFP catalyzed the reduction reactions of 2,6-DNP and BCB by NaBH 4 with psuedo-first order rate constants of 0.0451 and 0.1987min -1 , respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

Fabrication of 100 A class, 1 m long coated conductor tapes by metal organic chemical vapor deposition and pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Selvamanickam, V.; Lee, H.G.; Li, Y.; Xiong, X.; Qiao, Y.; Reeves, J.; Xie, Y.; Knoll, A.; Lenseth, K

2003-10-15

SuperPower has been scaling up YBa{sub 2}Cu{sub 3}O{sub x}-based second-generation superconducting tapes by techniques such as pulsed laser deposition (PLD) using industrial laser and metal organic chemical vapor deposition (MOCVD). Both techniques offer advantage of high deposition rates, which is important for high throughput. Using highly-polished substrates produced in a reel-to-reel polishing facility and buffer layers deposited in a pilot ion beam assisted deposition facility, meter-long second-generation high temperature superconductor tapes have been produced. 100 A class, meter-long coated conductor tapes have been reproducibly demonstrated in this work by both MOCVD and PLD. The best results to date are 148 A over 1.06 m by MOCVD and 135 A over 1.1 m by PLD using industrial laser.

Determination of paraffins in food simulants and packaging materials by liquid chromatography with evaporative mass detection and identification of paraffin type by liquid chromatography/gas chromatography and fourier transform infrared spectroscopy

NARCIS (Netherlands)

Simal-Gándara, J.; Sarria-Vidal, M.; Rijk, M.A.H.

2000-01-01

A liquid chromatographic method with evaporative mass detection (EMD) is described for the determination of paraffins in food contact materials that do not contain polyolefin oligomers, or paraffins migrating from these materials into fatty food simulants or certain simple foods. A normal-phase

Coating of waste containing ceramic granules

International Nuclear Information System (INIS)

Neumann, W.; Kofler, O.

1979-01-01

Simulated high-level waste granules produced by fluidized-bed calcination were overcoated by chemical vapor deposition (CVD) with pyrocarbon and nickel in laboratory-scale experiments. Successful development enables pyrocrbon deposition at temperatures of 600 to 800 0 K. The coated granules have excellent properties for long-term waste storage

Proceedings of the 1987 coatings for advanced heat engines workshop

Energy Technology Data Exchange (ETDEWEB)

1987-01-01

This Workshop was conducted to enhance communication among those involved in coating development for improved heat engine performance and durability. We were fortunate to have Bill Goward review the steady progress and problems encountered along the way in the use of thermal barrier coatings (TBC) in aircraft gas turbine engines. Navy contractors discussed their work toward the elusive goal of qualifying TBC for turbine airfoil applications. In the diesel community, Caterpillar and Cummins are developing TBC for combustion chamber components as part of the low heat rejection diesel engine concept. The diesel engine TBC work is based on gas turbine technology with a goal of more than twice the thickness used on gas turbine engine components. Adoption of TBC in production for diesel engines could justify a new generation of plasma spray coating equipment. Increasing interests in tribology were evident in this Workshop. Coatings have a significant role in reducing friction and wear under greater mechanical loadings at higher temperatures. The emergence of a high temperature synthetic lubricant could have an enormous impact on diesel engine design and operating conditions. The proven coating processes such as plasma spray, electron-beam physical vapor deposition, sputtering, and chemical vapor deposition have shown enhanced capabilities, particularly with microprocessor controls. Also, the newer coating schemes such as ion implantation and cathodic arc are demonstrating intriguing potential for engine applications. Coatings will play an expanding role in higher efficiency, more durable heat engines.

Photocured epoxy/graphene nanocomposites with enhanced water vapor barrier properties

Science.gov (United States)

Periolatto, M.; Sangermano, M.; Spena, P. Russo

2016-05-01

A transparent, water vapor barrier film made of an epoxy resin and graphene oxide (GO) was synthesized by photopolymerization process. The epoxy/GO film with just 0.05 wt% GO gives a 93% WVTR reduction with respect to the pristine polymer, reaching barrier properties better than other polymer composites containing higher amounts of graphene. The excellent water vapor barrier is attributed to the good dispersion of GO in the polymer matrix. Moreover, GO significantly enhances the toughness and the damping capacity of the epoxy resins. The hybrid film can have potential applications in anticorrosive coatings, electronic devices, pharmaceuticals and food packaging.

Photocured epoxy/graphene nanocomposites with enhanced water vapor barrier properties

Energy Technology Data Exchange (ETDEWEB)

Periolatto, M.; Spena, P. Russo [Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 5, Bolzano (Italy); Sangermano, M. [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, Torino (Italy)

2016-05-18

A transparent, water vapor barrier film made of an epoxy resin and graphene oxide (GO) was synthesized by photopolymerization process. The epoxy/GO film with just 0.05 wt% GO gives a 93% WVTR reduction with respect to the pristine polymer, reaching barrier properties better than other polymer composites containing higher amounts of graphene. The excellent water vapor barrier is attributed to the good dispersion of GO in the polymer matrix. Moreover, GO significantly enhances the toughness and the damping capacity of the epoxy resins. The hybrid film can have potential applications in anticorrosive coatings, electronic devices, pharmaceuticals and food packaging.

Photocured epoxy/graphene nanocomposites with enhanced water vapor barrier properties

International Nuclear Information System (INIS)

Periolatto, M.; Spena, P. Russo; Sangermano, M.

2016-01-01

A transparent, water vapor barrier film made of an epoxy resin and graphene oxide (GO) was synthesized by photopolymerization process. The epoxy/GO film with just 0.05 wt% GO gives a 93% WVTR reduction with respect to the pristine polymer, reaching barrier properties better than other polymer composites containing higher amounts of graphene. The excellent water vapor barrier is attributed to the good dispersion of GO in the polymer matrix. Moreover, GO significantly enhances the toughness and the damping capacity of the epoxy resins. The hybrid film can have potential applications in anticorrosive coatings, electronic devices, pharmaceuticals and food packaging.

Novel thermal barrier coatings based on La{sub 2}(Zr{sub 0.7}Ce{sub 0.3}){sub 2}O{sub 7}/8YSZ double-ceramic-layer systems deposited by electron beam physical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Xu Zhenhua, E-mail: zhxuciac@yahoo.com.cn [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); He Shimei; He Limin; Mu Rende; Huang Guanghong [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Cao Xueqiang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2011-03-17

Research highlights: > LZ7C3 and YSZ have good chemical compatibility for the formation of DCL coating. > DCL coating has a longer lifetime than that of single layer coating of LZ7C3 or YSZ. > Similar TECs of LZ7C3 with YSZ coatings and YSZ coating with TGO layer. > Unique growth modes of columns within DCL coating. > Outward diffusion of Cr element (bond coat) into LZ7C3 layer. - Abstract: Double-ceramic-layer (DCL) thermal barrier coatings (TBCs) of La{sub 2}(Zr{sub 0.7}Ce{sub 0.3}){sub 2}O{sub 7} (LZ7C3) and yttria stabilized zirconia (YSZ) were deposited by electron beam-physical vapor deposition (EB-PVD). The thermal cycling test at 1373 K in an air furnace indicates the DCL coating has a much longer lifetime than the single layer LZ7C3 coating, and even longer than that of the single layer YSZ coating. The superior sintering-resistance of LZ7C3 coating, the similar thermal expansion behaviors of YSZ interlayer with LZ7C3 coating and thermally grown oxide (TGO) layer, and the unique growth modes of columns within DCL coating are all very helpful to the prolongation of thermal cycling life of DCL coating. The failure of DCL coating is mainly a result of the reduction-oxidation of cerium oxide, the crack initiation, propagation and extension, the abnormal oxidation of bond coat, the degradation of t'-phase in YSZ coating and the outward diffusion of Cr alloying element into LZ7C3 coating.

Intense pulsed light annealing of copper zinc tin sulfide nanocrystal coatings

Energy Technology Data Exchange (ETDEWEB)

Williams, Bryce A.; Smeaton, Michelle A.; Holgate, Collin S.; Trejo, Nancy D.; Francis, Lorraine F., E-mail: francis@umn.edu; Aydil, Eray S., E-mail: aydil@umn.edu [Department of Chemical Engineering and Materials Science, University of Minnesota, 151 Amundson Hall, 421 Washington Avenue SE, Minneapolis, Minnesota 55455 (United States)

2016-09-15

A promising method for forming the absorber layer in copper zinc tin sulfide [Cu{sub 2}ZnSnS{sub 4} (CZTS)] thin film solar cells is thermal annealing of coatings cast from dispersions of CZTS nanocrystals. Intense pulsed light (IPL) annealing utilizing xenon flash lamps is a potential high-throughput, low-cost, roll-to-roll manufacturing compatible alternative to thermal annealing in conventional furnaces. The authors studied the effects of flash energy density (3.9–11.6 J/cm{sup 2}) and number of flashes (1–400) during IPL annealing on the microstructure of CZTS nanocrystal coatings cast on molybdenum-coated soda lime glass substrates (Mo-coated SLG). The annealed coatings exhibited cracks with two distinct linear crack densities, 0.01 and 0.2 μm{sup −1}, depending on the flash intensity and total number of flashes. Low density cracking (0.01 μm{sup −1}, ∼1 crack per 100 μm) is caused by decomposition of CZTS at the Mo-coating interface. Vapor decomposition products at the interface cause blisters as they escape the coating. Residual decomposition products within the blisters were imaged using confocal Raman spectroscopy. In support of this hypothesis, replacing the Mo-coated SLG substrate with quartz eliminated blistering and low-density cracking. High density cracking is caused by rapid thermal expansion and contraction of the coating constricted on the substrate as it is heated and cooled during IPL annealing. Finite element modeling showed that CZTS coatings on low thermal diffusivity materials (i.e., SLG) underwent significant differential heating with respect to the substrate with rapid rises and falls of the coating temperature as the flash is turned on and off, possibly causing a build-up of tensile stress within the coating prompting cracking. Use of a high thermal diffusivity substrate, such as a molybdenum foil (Mo foil), reduces this differential heating and eliminates the high-density cracking. IPL annealing in presence of sulfur

Effect of Cs and Li atom adsorption on MgO: Secondary emission and work function

International Nuclear Information System (INIS)

Bagraev, N.T.; Borisov, V.L.

1980-01-01

Adsorption of Cs and Li atoms on the surface of single crystal magnesium oxide films has been investigated using Auger, LEED and contact difference techniques. A decreased work function for a single crystal MgO film grown on the Mo (100) face was observed to be accompanied by an increased secondary electron emission yield shown to be due to a larger escape depth for secondary electrons. LEED showed well ordered layers of adsorbed Cs on the MgO film surface. A model to explain the behaviour of Cs atoms on the film surface is proposed. It is shown that the stability of the Cs coating is not dependent on a prolonged bombardment of the film by incident electron beams of high current density. Depositing and implanting of thin single crystal MgO films with Li were found to result in an increased secondary electron emission yield, with Li adsorption on the MgO film surface being disordered. (orig.)

Oils; lubricants; paraffin-wax compositions; hydrocarbon condensation products

Energy Technology Data Exchange (ETDEWEB)

1934-04-04

Petroleum hydrocarbons such as gasoline, kerosene, Diesel fuel oil, lubricating-oil, and paraffin wax, and like hydrocarbons such as are obtainable from shale oil and by the hydrogenation of carbonaceous materials, are improved by addition of products obtained by condensing a cyclic hydrocarbon with a saturated dihalogen derivative of an aliphatic hydrocarbon containing less than five carbon atoms. The addition of the condensation products increases the viscosity of the hydrocarbon oils specified, and is particularly useful in the case of lubricating-oils; addition of the condensation products to paraffin wax increases the transparency and adherent properties of the wax, and is useful in the manufacture of moulded articles such as candles; the products may also be used in solid lubricating-compositions.

Scoping studies of vapor behavior during a severe accident in a metal-fueled reactor

International Nuclear Information System (INIS)

Spencer, B.W.; Marchaterre, J.F.

1985-01-01

Scoping calculations have been performed examining the consequences of fuel melting and pin failures for a reactivity-insertion type accident in a sodium-cooled, pool-type reactor fueled with a metal alloy fuel. The principal gas and vapor species released are shown to be Xe, Cs,and bond sodium contained within the fuel porosity. Fuel vapor pressure is insignificant, and there is no energetic fuel-coolant interaction for the conditions considered. Condensation of sodium vapor as it expands into the upper sodium pool in a jet mixing regime may occur as rapidly as the vapor emerges from the disrupted core (although reactor-material experiments are needed to confirm these high condensation rates). If the predictions of rapid direct-contact condensation can be verified experimentally for the sodium system, the implication is that the ability of vapor expansion to perform appreciable work on the system is largely eliminated. Furthermore, the ability of an expanding vapor bubble to transport fuel and fission product species to the cover gas region where they may be released to the containment is also largely eliminated. The radionuclide species except for fission gas are largely retained within the core and sodium pool

Separation of Olefin/Paraffin Mixtures with Carrier Facilitated Membrane Final Report

Energy Technology Data Exchange (ETDEWEB)

Merkel, T.C.; Blanc, R.; Zeid, J.; Suwarlim, A.; Firat, B.; Wijmans, H.; Asaro, M. (SRI); Greene, M.(Lummus)

2007-03-12

This document describes the results of a DOE funded joint effort of Membrane Technology and Research Inc. (MTR), SRI International (SRI), and ABB Lummus (ABB) to develop facilitated transport membranes for olefin/paraffin separations. Currently, olefin/paraffin separation is done by distillation—an extremely energy-intensive process because of the low relative volatilities of olefins and paraffins. If facilitated transport membranes could be successfully commercialized, the potential energy savings achievable with this membrane technology are estimated to be 48 trillion Btu per year by the year 2020. We discovered in this work that silver salt-based facilitated transport membranes are not stable even in the presence of ideal olefin/paraffin mixtures. This decline in membrane performance appears to be caused by a previously unrecognized phenomenon that we have named olefin conditioning. As the name implies, this mechanism of performance degradation becomes operative once a membrane starts permeating olefins. This project is the first study to identify olefin conditioning as a significant factor impacting the performance of facilitated olefin transport membranes. To date, we have not identified an effective strategy to mitigate the impact of olefin conditioning. other than running at low temperatures or with low olefin feed pressures. In our opinion, this issue must be addressed before further development of facilitated olefin transport membranes can proceed. In addition to olefin conditioning, traditional carrier poisoning challenges must also be overcome. Light, hydrogen, hydrogen sulfide, and acetylene exposure adversely affect membrane performance through unwanted reaction with silver ions. Harsh poisoning tests with these species showed useful membrane lifetimes of only one week. These tests demonstrate a need to improve the stability of the olefin complexing agent to develop membranes with lifetimes satisfactory for commercial application. A successful effort

Preparation of Paraffin@Poly(styrene-co-acrylic acid) Phase Change Nanocapsules via Combined Miniemulsion/Emulsion Polymerization.

Science.gov (United States)

Zhang, Feng; Liu, Tian-Yu; Hou, Gui-Hua; Guan, Rong-Feng; Zhang, Jun-Hao

2018-06-01

The fast development of solid-liquid phase change materials calls for nanomaterials with large specific surface area for rapid heat transfer and encapsulation of phase change materials to prevent potential leakage. Here we report a combined miniemulsion/emulsion polymerization method to prepare poly(styrene-co-acrylic acid)-encapsulated paraffin (paraffin@P(St-co-AA)) nanocapsules. The method could suppress the shortcomings of common miniemulsion polymerization (such as evaporation of monomer and decomposition of initiator during ultrasonication). The paraffin@P(St-co-AA) nanocapsules are uniform in size and the polymer shell can be controlled by the weight ratio of St to paraffin. The phase change behavior of the nanocapsules is similar to that of pure paraffin. We believe our method can also be utilized to synthesize other core-shell phase change materials.

Single-photon cesium Rydberg excitation spectroscopy using 318.6-nm UV laser and room-temperature vapor cell.

Science.gov (United States)

Wang, Jieying; Bai, Jiandong; He, Jun; Wang, Junmin

2017-09-18

We demonstrate a single-photon Rydberg excitation spectroscopy of cesium (Cs) atoms in a room-temperature vapor cell. Cs atoms are excited directly from 6S 1/2 ground state to nP 3/2 (n = 70 - 100) Rydberg states with a 318.6 nm ultraviolet (UV) laser, and Rydberg excitation spectra are obtained by transmission enhancement of a probe beam resonant to Cs 6S 1/2 , F = 4 - 6P 3/2 , F' = 5 transition as partial population on F = 4 ground state are transferred to Rydberg state. Analysis reveals that the observed spectra are velocity-selective spectroscopy of Rydberg state, from which the amplitude and linewidth influenced by lasers' Rabi frequency have been investigated. Fitting to energies of Cs nP 3/2 (n = 70 -100) states, the determined quantum defect is 3.56671(42). The demodulated spectra can also be employed as frequency references to stabilize the UV laser frequency to specific Cs Rydberg transition.

Quantifying Short-Chain Chlorinated Paraffin Congener Groups

NARCIS (Netherlands)

Yuan, Bo; Bogdal, Christian; Berger, Urs; MacLeod, Matthew; Gebbink, Wouter A.; Alsberg, Tomas; Wit, de Cynthia A.

2017-01-01

Accurate quantification of short-chain chlorinated paraffins (SCCPs) poses an exceptional challenge to analytical chemists. SCCPs are complex mixtures of chlorinated alkanes with variable chain length and chlorination level; congeners with a fixed chain length (n) and number of chlorines (m) are

Study on the bonding strength between calcium phosphate/chitosan composite coatings and a Mg alloy substrate

Energy Technology Data Exchange (ETDEWEB)

Zhang Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Pharmacy College, Jiamusi University, Jiamusi 154007 (China); Dai Changsong, E-mail: changsd@hit.edu.cn [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Wei Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); School of Chemistry and Bioengineering, Suzhou Science Technology University, Suzhou 215009 (China); Wen Zhaohui, E-mail: wenzhaohui1968@163.com [Department of Neuro intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China)

2012-11-15

Highlights: Black-Right-Pointing-Pointer Calcium phosphate/chitosan composite coatings on the MAO-AZ91D alloy were prepared. Black-Right-Pointing-Pointer The bonding force between the coating and the magnesium alloy was optimized. Black-Right-Pointing-Pointer The composite coating slowed down the corrosion rate of magnesium alloy in m-SBF. - Abstract: In order to improve the bonding strength between calcium phosphate/chitosan composite coatings and a micro-arc oxidized (MAO)-AZ91D Mg alloy, different influencing parameters were investigated in the process of electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). Surface morphology and phase constituents of the as-prepared materials were investigated by using X-ray diffractometer (XRD), Fourier-transformed infrared spectrophotometer (FTIR), Raman spectrometer, scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), and a thermo gravimetric and differential thermal analyzer (TG-DTA). Scratch tests were carried out to study the bonding properties between the coatings and the substrates. In vitro immersion tests were conducted to determine the corrosion behaviors of samples with and without deposit layers through electrochemical experiments. In the EPD process, the acetic acid content in the electrophoresis suspension and the electrophoretic voltage played important roles in improving the bonding properties, while the contents of chitosan (CS) and nano-hydroxyapatite (nHA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) in the suspension had less significant influences on the mechanical bonding strength. It was observed that the coatings showed the excellent bonding property when an electrophoretic voltage was in a range of 40-110 V with other reagent amounts as follows: acetic acid: 4.5 vol.%, CS {<=} 0.25 g, nHA {<=} 2.0 g in 200 ml of a CS-acetic acid aqueous solution and nHA {<=} 2.5 g in 300 ml of absolute ethanol. The morphology of the composite coating

Titanium tungsten coatings for bioelectrochemical applications

DEFF Research Database (Denmark)

Wierzbicki, Rafal; Amato, Letizia; Łopacińska, J.

2011-01-01

This paper presents an assessment of titanium tungsten (TiW) coatings and their applicability as components of biosensing systems. The focus is put on using TiW as an electromechanical interface layer between carbon nanotube (CNT) forests and silicon nanograss (SiNG) cell scaffolds. Cytotoxicity......, applicability to plasma-enhanced chemical vapor deposition (PECVD) of aligned CNT forests, and electrochemical performance are investigated. Experiments include culturing of NIH3T3 mouse embryonic fibroblast cells on TiW coated silicon scaffolds, CNT growth on TiW substrates with nickel catalyst, and cyclic...

Preparation and Properties of Paraffin/TiO2/Active-carbon Composite Phase Change Materials

Directory of Open Access Journals (Sweden)

HAO Yong-gan

2016-11-01

Full Text Available A novel composite phase change materials (PCMs of paraffin/TiO2/active-carbon was prepared by a microemulsion method, where paraffin acted as a PCM and titanium dioxide (TiO2 as matrix material, and a small amount of active carbon was added to improve the thermal conductivity. The compositions, morphology and thermal properties of the paraffin/TiO2/active-carbon composite PCMs were characterized by XRD, SEM, TGA and DSC respectively. The shape stability during phase change process of this composite was also tested. The results show that paraffin is well encapsulated by TiO2 matrix, and thus exhibiting excellent shape-stabilized phase change feature. Besides, this composite PCM also presents superhydrophobic property. Therefore, these multifunctional features will endow PCMs with important application potential in energy efficient buildings.

Coated air-stable cobalt--rare earth alloy particles and method

International Nuclear Information System (INIS)

Smeggil, J.C.; Charles, R.J.

1975-01-01

A process is described for producing novel air-stable coated particles of a magnetic transition metal-rare earth alloys. An organometallic compound which decomposes at a temperature below 500 0 C is heated to produce a metal vapor which is contacted with particles of a transition metal-rare earth alloy to deposit a metal coating on the particles. (U.S.)

Analysis of hepcidin expression: in situ hybridization and quantitative polymerase chain reaction from paraffin sections.

Science.gov (United States)

Sakuraoka, Yuhki; Sawada, Tokihiko; Shiraki, Takayuki; Park, Kyunghwa; Sakurai, Yuhichiro; Tomosugi, Naohisa; Kubota, Keiichi

2012-07-28

To establish methods for quantitative polymerase chain reaction (PCR) for hepcidin using RNAs isolated from paraffin-embedded sections and in situ hybridization of hepatocellular carcinoma (HCC). Total RNA from paraffin-embedded sections was isolated from 68 paraffin-embedded samples of HCC. Samples came from 54 male and 14 female patients with a mean age of 66.8 ± 7.8 years. Quantitative PCR was performed. Immunohistochemistry and in situ hybridization for hepcidin were also performed. Quantitative PCR for hepcidin using RNAs isolated from paraffin-embedded sections of HCC was performed successfully. The expression level of hepcidin mRNA in cancer tissues was significantly higher than that in non-cancer tissues. A method of in situ hybridization for hepcidin was established successfully, and this demonstrated that hepcidin mRNA was expressed in non-cancerous tissue but absent in cancerous tissue. We have established novel methods for quantitative PCR for hepcidin using RNAs isolated from paraffin-embedded sections and in situ hybridization of HCC.

Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

Science.gov (United States)

Gartner, Hunter; Li, Yana; Almenar, Eva

2015-03-01

The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41-35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228-303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film.

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.)

Radiotherapic Valuation of Paraffin Wax for Patients with Oral Cancer

International Nuclear Information System (INIS)

Na, Kyung Su; Seo, Seuk Jin; Lee, Je Hee; Yoo, Sook Heun