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AbstractAbstract
[en] This paper deals with modeling of the first damage mode, matrix micro-cracking, in helicopter rotor/wind turbine blades and how this effects the overall cross-sectional stiffness. The helicopter/wind turbine rotor system operates in a highly dynamic and unsteady environment leading to severe vibratory loads present in the system. Repeated exposure to this loading condition can induce damage in the composite rotor blades. These rotor/turbine blades are generally made of fiber-reinforced laminated composites and exhibit various competing modes of damage such as matrix micro-cracking, delamination, and fiber breakage. There is a need to study the behavior of the composite rotor system under various key damage modes in composite materials for developing Structural Health Monitoring (SHM) system. Each blade is modeled as a beam based on geometrically non-linear 3-D elasticity theory. Each blade thus splits into 2-D analyzes of cross-sections and non-linear 1-D analyzes along the beam reference curves. Two different tools are used here for complete 3-D analysis: VABS for 2-D cross-sectional analysis and GEBT for 1-D beam analysis. The physically-based failure models for matrix in compression and tension loading are used in the present work. Matrix cracking is detected using two failure criterion: Matrix Failure in Compression and Matrix Failure in Tension which are based on the recovered field. A strain variable is set which drives the damage variable for matrix cracking and this damage variable is used to estimate the reduced cross-sectional stiffness. The matrix micro-cracking is performed in two different approaches: (i) Element-wise, and (ii) Node-wise. The procedure presented in this paper is implemented in VABS as matrix micro-cracking modeling module. Three examples are presented to investigate the matrix failure model which illustrate the effect of matrix cracking on cross-sectional stiffness by varying the applied cyclic load
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ICNAAM-2014: International Conference on Numerical Analysis and Applied Mathematics 2014; Rhodes (Greece); 22-28 Sep 2014; (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
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AbstractAbstract
[en] In order to understand the importance of the retrogression and re-aging as a heat treatment for improving microstructural and mechanical properties of the Al-Zn-Mg-Cu powder metallurgy alloys, Al-Zn-Mg-Cu-Fe-Cr alloys were fabricated from the elemental powders. Green compacts are compressed under compaction pressure about 370 MPa. The sintering process carried out for the samples of aluminum alloys at temperature was 650°C under argon atmosphere for two hours. The sintered compacts were subjected into homogenizing condition at 470°C for 1.5 hours and then aged at 120°C for 24 hours (T6 temper) after that it carried out the retrogressed at 180°C for 30 min., and then re-aged at 120°C for 24 hours (RRA). Observations microstructures were examined using optical, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray diffraction. Density and porosity content was conducted for the samples of alloys. The result showing that the highest Vickers hardness exhibited for an Al-Zn-Mg-Cu alloy after underwent the retrogression and reaging treatment. Increasing in hardness was because of the precipitation hardening through precipitate the (Mg Zn) and (Mg2Zn11) phases during matrix of aluminum-alloy
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ICoMEIA 2014: International Conference on Mathematics, Engineering and Industrial Applications 2014; Penang (Malaysia); 28-30 May 2014; (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
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AbstractAbstract
[en] Superhydrophobic surfaces with contact angle (CA) >150 and sliding angle (SA) <10 have been aroused curiosity over the years due to their various applications. Superhydrophobicity can be obtained tailoring the chemistry and the roughness of the surface, mimicking the Lotus flower. Most superhydrophobic surfaces based on secondary bonding lose their roughness in harsh conditions and are unsuitable for practical applications. Photoreactive SiO2 nanoparticles (NPs) based on benzophenone (BP) can be a very effective tool for formation of reactive species that function as a molecular bridge by covalent bonding between the NP and any polymer matrix with C-C and C-H bonds. The present work focused on thermoset radiation curing urethane acrylate. Upon UV irradiation reactive excited nπ* triplet benzophenone species are formed and react through hydrogen abstraction to form ketyl radicals which interact with a radicals from the UV irradiated polymer matrix to yield covalent bonding. Roughness was achieved by dipping the substrate in SiO2@BPs NPs dispersion followed by irradiation. Fluoroalkylsilane was used to obtain hydrophobic top layer. AFM nano manipulation was used to verify the immobilization of NPs. Evaluation of durability was made using air flow at 300 km/hr. Preliminary results indicate the formation of super hydrophobic surfaces (CA>150 and SA<10) with improved stability
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PPS-30: 30. International Conference of the Polymer Processing Society; Cleveland, OH (United States); 6-12 Jun 2014; (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
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BORON COMPOUNDS, CARBAMATES, CARBONIC ACID DERIVATIVES, CARBOXYLIC ACID SALTS, CHALCOGENIDES, CHEMICAL RADIATION EFFECTS, CURING, ELECTROMAGNETIC RADIATION, FABRICATION, JOINING, LIFETIME, MATERIALS, MECHANICAL PROPERTIES, MICROSCOPY, MINERALS, ORGANIC COMPOUNDS, ORGANIC NITROGEN COMPOUNDS, OXIDE MINERALS, OXIDES, OXYGEN COMPOUNDS, PARTICLES, PHOSPHIDES, PHOSPHORUS COMPOUNDS, PNICTIDES, POLYMERS, RADIATION EFFECTS, RADIATIONS, SILICON COMPOUNDS, SURFACE PROPERTIES
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AbstractAbstract
[en] We investigated the efficient use of cellulose to resolve the problem of the depletion of fossil resources. In this study, as the biomass material, the green composite based on natural rubber (NR) and the flake-shaped cellulose particles (FSCP) was produced. In order to further improvement of functional characteristics, epoxidized natural rubber (ENR) was also used instead of NR. The FSCP were produced by mechanical milling in a planetary ball mill with a grinding aid as a cellulose aggregation inhibitor. Moreover, talc and mica particles were used to compare with FSCP. NR and ENR was mixed with vulcanizing agents and then each filler was added to NR compound in an internal mixer. The vulcanizing agents are as follows: stearic acid, zinc oxide, sulfur, and vulcanization accelerator. The functionalities of the composites were evaluated by a vibration-damping experiment and a gas permeability experiment. As a result, we found that FSCP filler has effects similar to (or more than) inorganic filler in vibration-damping and O2 barrier properties. And then, vibration- damping and O2 barrier properties of the composite including FSCP was increased with use of ENR. In particular, we found that ENR-50 composite containing 50 phr FSCP has three times as high vibration-damping property as ENR-50 without FSCP
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PPS-30: 30. International Conference of the Polymer Processing Society; Cleveland, OH (United States); 6-12 Jun 2014; (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
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CARBOHYDRATES, CARBOXYLIC ACIDS, CHALCOGENIDES, COMMINUTION, ELASTOMERS, ELEMENTS, ENERGY SOURCES, EVALUATION, MACHINING, MATERIALS, MINERALS, MONOCARBOXYLIC ACIDS, NONMETALS, ORGANIC ACIDS, ORGANIC COMPOUNDS, ORGANIC POLYMERS, OXIDES, OXYGEN COMPOUNDS, PHYSICAL PROPERTIES, POLYMERS, POLYSACCHARIDES, RENEWABLE ENERGY SOURCES, RUBBERS, SACCHARIDES, SILICATE MINERALS, ZINC COMPOUNDS
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Chang, H. W.; Liao, M. C.; Shih, C. W.; Chang, W. C.; Yang, C. C.; Hsiao, C. H.; Ouyang, H., E-mail: phywcc@ccu.edu.tw2014
AbstractAbstract
[en] Hard magnetic property enhancement of melt spun Co88Hf12 ribbons by boron doping is demonstrated. B-doping could not only remarkably enhance the magnetic properties from energy product ((BH)max) of 2.6 MGOe and intrinsic coercivity (iHc) of 1.5 kOe for B-free Co88Hf12 ribbons to (BH)max = 7.7 MGOe and iHc = 3.1 kOe for Co85Hf12B3 ribbons but also improve the Curie temperature (TC) of 7:1 phase. The (BH)max value achieved in Co85Hf12B3 ribbons is the highest in Co-Hf alloy ribbons ever reported, which is about 15% higher than that of Co11Hf2B ribbons spun at 16 m/s [M. A. McGuire, O. Rios, N. J. Ghimire, and M. Koehler, Appl. Phys. Lett. 101, 202401 (2012)]. The structural analysis confirms that B enters the orthorhombic Co7Hf (7:1) crystal structure as interstitial atoms, forming Co7HfBx, in the as-spun state. Yet B may diffuse out from the 7:1 phase after post-annealing, leading to the reduction of Curie temperature and the magnetic properties. The uniformly refined microstructure with B-doping results in high remanence (Br) and improves the squareness of demagnetization curve. The formation of interstitial-atom-modified Co7HfBx phase and the microstructure refinement are the main reasons to give rise to the enhancement of hard magnetic properties in the B-containing Co7Hf-based ribbons
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(c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
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AbstractAbstract
[en] The growth and electrical characterization of the heterojunction formed between two-dimensional (2D) layered p-molybdenum disulfide (MoS2) and nitrogen-doped 4H silicon carbide (SiC) are reported. The integration of 2D semiconductors with the conventional three-dimensional (3D) substrates could enable semiconductor heterostructures with unprecedented properties. In this work, direct growth of p-type MoS2 films on SiC was demonstrated using chemical vapor deposition, and the MoS2 films were found to be high quality based on x-ray diffraction and Raman spectra. The resulting heterojunction was found to display rectification and current-voltage characteristics consistent with a diode for which forward conduction in the low-bias region is dominated by multi-step recombination tunneling. Capacitance-voltage measurements were used to determine the built-in voltage for the p-MoS2/n-SiC heterojunction diode, and we propose an energy band line up for the heterostructure based on these observations. The demonstration of heterogeneous material integration between MoS2 and SiC enables a promising new class of 2D/3D heterostructures
Primary Subject
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(c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
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CARBIDES, CARBON COMPOUNDS, CHALCOGENIDES, CHEMICAL COATING, COHERENT SCATTERING, CRYSTAL LATTICES, CRYSTAL STRUCTURE, DEPOSITION, DIFFRACTION, ELEMENTS, MATERIALS, MOLYBDENUM COMPOUNDS, NONMETALS, REFRACTORY METAL COMPOUNDS, SCATTERING, SEMICONDUCTOR JUNCTIONS, SILICON COMPOUNDS, SPECTRA, SULFIDES, SULFUR COMPOUNDS, SURFACE COATING, TRANSITION ELEMENT COMPOUNDS
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Oguchi, Hiroyuki; Ikeshoji, Tamio; Orimo, Shin-ichi; Ohsawa, Takeo; Shiraki, Susumu; Hitosugi, Taro; Kuwano, Hiroki, E-mail: oguchi@nanosys.mech.tohoku.ac.jp2014
AbstractAbstract
[en] We report on the synthesis of lithium hydride (LiH) epitaxial thin films through the hydrogenation of a Li melt, forming abrupt LiH/MgO interface. Experimental and first-principles molecular dynamics studies reveal a comprehensive microscopic picture of the crystallization processes, which sheds light on the fundamental atomistic growth processes that have remained unknown in the vapor-liquid-solid method. We found that the periodic structure that formed, because of the liquid-Li atoms at the film/MgO-substrate interface, serves as an atomic template for the epitaxial growth of LiH crystals. In contrast, films grown on the Al2O3 substrates indicated polycrystalline films with a LiAlO2 secondary phase. These results and the proposed growth process provide insights into the preparation of other alkaline metal hydride thin films on oxides. Further, our investigations open the way to explore fundamental physics and chemistry of metal hydrides including possible phenomena that emerge at the heterointerfaces of metal hydrides
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(c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
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ALKALI METAL COMPOUNDS, ALKALINE EARTH METAL COMPOUNDS, ALUMINIUM COMPOUNDS, CALCULATION METHODS, CHALCOGENIDES, CHEMICAL REACTIONS, CRYSTAL GROWTH METHODS, CRYSTALS, FILMS, FLUIDS, GASES, HYDRIDES, HYDROGEN COMPOUNDS, LITHIUM COMPOUNDS, MAGNESIUM COMPOUNDS, OXIDES, OXYGEN COMPOUNDS, PHASE TRANSFORMATIONS
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AbstractAbstract
[en] A new process has been developed to deposit magnesium fluoride (MgF2) thin films via atomic layer deposition (ALD) for use as optical coatings in the ultraviolet. MgF2 was deposited in a showerhead style ALD reactor using bis(ethylcyclopentadienyl)magnesium and anhydrous hydrogen fluoride (HF) as precursors at substrate temperatures from 100 to 250 °C. The use of HF was observed to result in improved morphology and reduced impurity content compared to other reported MgF2 ALD approaches that use metal fluoride precursors as the fluorine-containing chemistry. Characterization of these films has been performed using spectroscopic ellipsometry, atomic force microscopy, and x-ray photoelectron spectroscopy for material deposited on silicon substrates. Films at all substrate temperatures were transparent at wavelengths down to 190 nm and the low deposition temperature combined with low surface roughness makes these coatings good candidates for a variety of optical applications in the far ultraviolet
Primary Subject
Source
(c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
Journal
Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; ISSN 0734-2101;
; CODEN JVTAD6; v. 33(1); vp

Country of publication
ALKALINE EARTH METAL COMPOUNDS, ELECTROMAGNETIC RADIATION, ELECTRON SPECTROSCOPY, FILMS, FLUORIDES, FLUORINE COMPOUNDS, HALIDES, HALOGEN COMPOUNDS, HYDROGEN COMPOUNDS, HYDROGEN HALIDES, INORGANIC ACIDS, INORGANIC COMPOUNDS, MAGNESIUM COMPOUNDS, MAGNESIUM HALIDES, MEASURING METHODS, MICROSCOPY, PHOTOELECTRON SPECTROSCOPY, RADIATIONS, SPECTROSCOPY, SURFACE PROPERTIES, ULTRAVIOLET RADIATION
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Maniwa, Atsushi; Chiba, Hirokazu; Kawano, Kazuhisa; Koiso, Naoyuki; Oike, Hiroyuki; Furukawa, Taishi; Tada, Ken-ichi, E-mail: atsushi-maniwa-ht@tosoh.co.jp2015
AbstractAbstract
[en] The authors have succeeded in development of a novel Ru precursor, Ru(EtCp)(η5-CH2C(Me)CHC(Me)O) [Rudense], for CVD and atomic layer deposition (ALD) processes under nonoxidative condition. Rudense has sufficient vapor pressure and good thermal stability (decomposition temperature = ca. 230 °C). Ru thin films were grown on Pt, Ru, Si, and SiO2 substrates using Rudense and NH3 as Ru precursor and reactant, respectively. Rudense gave the conformal, low-impurity (<1021 atoms/cc), and low-resistivity (16 μΩ cm) Ru thin films. Moreover, Rudense showed substrate selectivity; therefore, Rudense will be a candidate for area-selective CVD and ALD precursor for Ru capping layers of Cu interconnects
Primary Subject
Source
(c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; ISSN 0734-2101;
; CODEN JVTAD6; v. 33(1); vp

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
External URLExternal URL
AbstractAbstract
[en] To obtain strong perpendicular magnetic anisotropy (PMA) based on L10 structure for magnetic storage devices, costly single crystalline substrates are generally required to achieve (001) texture. Recently, various studies also have focused on depositing different kinds of seed layers on glass or other amorphous substrates to promote (001) preferred orientation of L10 CoPt and FePt. TiN is a very promising seed layer material because of its cubic crystalline structure (similar to MgO) and excellent diffusion barring property even at high temperatures. In the present work, highly (001) oriented L10-CoPt/TiN multilayer films have been successfully deposited on glass substrates. After annealing at 700 °C, the film exhibits PMA, and a strong (001) peak is detected from the x-ray diffraction profiles, indicating the ordering transformation of CoPt layers from fcc (A1) to L10 structure. It also is found that alternate deposition of cubic TiN and CoPt effectively improves the crystallinity and (001) preferred orientation of CoPt layers. This effect is verified by the substantial enhancement of (001) reflection and PMA with increasing the period number of the multilayer films
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Source
(c) 2015 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; ISSN 0734-2101;
; CODEN JVTAD6; v. 33(2); p. 021512-021512.5

Country of publication
ALKALINE EARTH METAL COMPOUNDS, CHALCOGENIDES, COHERENT SCATTERING, CRYSTAL LATTICES, CRYSTAL STRUCTURE, CUBIC LATTICES, DIFFRACTION, ELEMENTS, MAGNESIUM COMPOUNDS, MEMORY DEVICES, METALS, MICROSTRUCTURE, NITRIDES, NITROGEN COMPOUNDS, ORIENTATION, OXIDES, OXYGEN COMPOUNDS, PNICTIDES, SCATTERING, THREE-DIMENSIONAL LATTICES, TITANIUM COMPOUNDS, TRANSITION ELEMENT COMPOUNDS
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