bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of the Combinatorial Glass Formation Tester
Authors: Inoue Satoru , Todoroki Shin-ichi , Matsumoto Takehisa , Hondo Takaharu , Araki Tetsuo , Tsuchiya Toshio 
Published: April 2011

AbstractThe combinatorial glass formation tester has been developed to determine the glass forming regions as quickly as possible. The 24 glass batches of about 1g were put into each carbon crucible on a carbon holder and heated in an electric furnace filled with dry nitrogen gas. After about a half an hour heating, the crucibles were taken out from the furnace and moved into the cooling chamber purged with dry nitrogen gas. The holder and the crucibles were moved on to a cooling stage to be cooled down quickly with a water flowing jacket together with nitrogen gas blowing. The time interval after taking out of the crucibles till the placement on the cooling stage was shortened as much as possible, resulting to be 10sec. The temperature of the melt in the crucibles was measured with an optical pyrometer to estimate the cooling rate. The top view of the crucibles on the holder was taken with a CCD camera during cooling. The CCD figures were stored on a computer for the judgments of the transparency of the samples in the crucibles to compile a glass forming region. The glass formation tester can manage 24 glass melting tests every 1 hours. In other words, the tester can produce at least 192 glass samples (24 x 8=192) within a day working time. The speed was roughly 100 times larger than the case of manual operation.
Materials Development for Solid Oxide Fuel Cells Using Qualitative Models
Authors: Schmid Klaus , Krebs Volker , Krügel Albert , Ivers-Tiée Ellen , Schäfer Sven 
Published: April 2011

AbstractSolid Oxide Fuel Cells (SOFC) are high temperature energy converters. When an SOFC is operated for the rst time, a substantial increase in cell performance is observed which is caused by microstructural changes at the cathode/electrolyte interface. To optimize the resulting formation of the interface, a dynamic model is required that represents the relations between materials compositions, operating conditions, electric current, and microstructure.Building a model based on chemical reaction equations fails because of the high complexity of the interface reactions. Therefore, this contribution presents an interdisciplinary approach to modeling in materials development by applying computational intelligence techniques. Qualitative models are used to formalize the expert knowledge about the irreversible materials changes at the cathode/electrolyte interface. Fuzzy if-then rules represent the dynamic behavior of the microstructural formation. The resulting model enables the application of simulations instead of time-consuming experiments and thus allows the systematic optimization of the startup process.
The Influence of Many Body Interactions in the Stress-Velocity Relation of a Single Dislocation in a 2D Lattice.
Authors: Robles M. , Mustonen V. , Kaski K. , Patriarca M. 
Published: April 2011

ABSTRACTThe stress-velocity relation of a single dislocation moving in a 2-D lattice has been studied using interactive molecular dynamic simulations. A hybrid interatomic model potential which couples Lennard-Jones(LJ) potential and the Embedded Atom Model (EAM) potential, is used to include radial and many body interactions. Both parts are assembled by a parameter so that the potential can be changed to describe a pure radial interaction to a strong many body interaction in a continuous way. Setting up a constant-stress scenario, the movement of a single dislocation is tracked from zero velocity state, up to a terminal velocity state. The external stress vs. terminal velocity curves have been obtained in the subsonic regime for different values of the coupling parameter. Non-linear relations are found velocity regime 0.1ct to 0.6ct, where ct is the transverse speed of sound. Results have been analyzed using an augmented Peierls model to seek the connection between atomic scale, continuum variables and the limiting speed of dislocations
Modeling Cascade Aging in Dilute Fe-Cu Alloys
Authors: Wirth B. D. , Odette G. R. 
Published: April 2011

ABSTRACTThe continued safe operation of nuclear reactors and their potential for lifetime extension depends on ensuring reactor pressure vessel integrity. Reactor pressure vessels and structural materials used in nuclear energy applications are exposed to intense neutron fields that create highly non-equilibrium defect concentrations, consisting of a shell of self-interstitial atom and clusters surrounding a vacancy-rich core, over picosecond time scales. This spatially correlated defect production initiates a long chain of events responsible for microstructure evolution and hence irradiation embrittlement. In this paper, we describe the combined use of molecular dynamics (MD) and kinetic lattice Monte Carlo (KMC) to simulate the long-term rearrangement (aging) of displacement cascades in dilute Fe-Cu alloys. The simulations reveal the formation of a continuous distribution of three dimensional cascade vacancy-Cu cluster complexes and demonstrate the critical importance of spatial, as well as short and long-time correlated processes that mediate the effective production of primary defects. Finally, this approach can generate production cross-sections for vacancy-Cu clusters that can then be used in rate theory type models of long term global micro and microstructural evolution.
Phase Transformations Induced by Arsenic Implants into Silicon
Authors: Lavine James P. , Tuschel David D. , Black Donald L. 
Published: April 2011

ABSTRACTMicro-Raman spectroscopic investigations of arsenic-implanted silicon show lines characteristic of silicon crystallites even at implant doses above the amorphization threshold. The intensity and frequency of occurrence of the lines increase with the implanted dose. Polarization/orientation Raman studies indicate the crystallites are silicon in the hexagonal phase (Si-IV) and silicon in the diamond phase (Si-I). The latter are oriented differently than the substrate silicon. Monte Carlo simulations of the arsenic ion energy loss and published molecular dynamics studies suggest that each arsenic ion deposits sufficient energy to locally melt the silicon lattice. This is taken as the basis of the present attempt to explain the origin of the crystallites. A one-dimensional numerical model is developed to determine the time scale for the liquid silicon to solidify. The effect of amorphous silicon on the solidification is also investigated.
Keratin Protein Nano-fiber for Removal of Heavy Metals and Contaminants
Authors: Misra M. , Kar P. , Priyadarshan G. , Licata Carlo 
Published: April 2011

ABSTRACTKeratin protein fiber (AKF™) is a renewable source of biosorbent that can be used for filtration of heavy metal and nanosize contaminants. The major composition of keratin fiber is the structured protein micofibril, consisting of numerous nanosized pores. The combination of nanostructure and metal binding capacity protein sites make it an ideal material for removal of heavy metals from solutions. The mechanism of heavy metal uptake onto keratin protein involves a combination of several steps such as adsorption, precipitation, and ion exchange. Keratin protein has good tensile strength and is stable over a wide pH range.
A New Hybrid Aerogel Approach to Modification of Bioderived Polymers for Materials Applications
Authors: Wang Mingzhe , Liu Xipeng , Ji Shuang , Risen William M. 
Published: April 2011

ABSTRACTNovel hybrid aerogels consisting of the bioderived polymers chitosan, pectic acid or alginic acid and silica have been synthesized as clear monoliths from clear gels by supercritical fluid extraction. These renewable resource polymers, which are soluble and typically unassociated in aqueous systems, are separately arranged in aerogel scaffolding. This makes them exposed and available for reactions that in some cases would not be possible in aqueous systems. Thus, it is possible to react the amine groups of chitosan, a polymer derived from chitin, with isocyanate-terminated prepolymers to form urea linkages and to form new linked chitosan materials. Following the reactions, the scaffold can be dissolved and the new material isolated. Variations lead to hydrophobic or hydrophilic materials. The reactions of aerogel scaffolded bioderived polymers to form urethane-or amide-group linked materials also will be presented and the properties of newly formed materials will be described. Further reactions enabled by the approach, including ones leading to radiation curable polymeric systems will be presented.
Characterization of Renewable Composites
Authors: Emekalam A. , Gu X. , Raghavan D. 
Published: April 2011

ABSTRACTIn this study, we demonstrate the usefulness of chemical based method in combination with AFM to characterize a wide range of degradable polymer blends. This approach is based on selective degradation of one of the phase in a multi-phase system and the ability of TMAFM to provide nanoscale lateral information about the different phases in the polymer system. Composite films containing different percentage of hydrolyzable polymer were either melt processed/solution casted and then exposed to a hydrolytic acidic environment and analyzed using TMAFM. Pits were observed to form in the blend films. The progressive hydrolysis of the hydrolyzable component in the composite was studied by FTIR analyses. TMAFM phase imaging was used to follow pit growth of the blend as a function of exposure time. The usefulness of the chemical modification/AFM approach in the characterization of renewable porous material membranes is discussed.
Injection Molding a Polyolefin-Based Nanocomposite versus a Talc-Filled TPO
Authors: Okonski David A. 
Published: April 2011

ABSTRACTGeneral Motors Research and Development and Basell Polyolefins have jointly developed a family of polyolefin-based nanocomposites for use in the injection molding of body-side claddings. Basell Polyolefins commercialized one of these materials as Hifax DX277 in September of 2000, and General Motors has exclusive use of this material. Confidence in the ability of DX277 to perform as intended is being reinforced by molding trials at various Tier 1 locations. In addition to mass savings, the nanocomposite material is showing a much wider processing window than conventional talc-filled TPO’s – allowing Tier 1 molders the opportunity to process away problems rather than initiating a tooling change. This paper will describe the processing advantages associated with the injection molding of a polyolefin-based nanocomposite over a conventional talc-filled TPO.
Glass and glass-ceramic matrix composites: from model systems to useful materials
Authors: Boccaccini Aldo R. , Kaya Cengiz 
Published: April 2011

ABSTRACTBy reinforcing glass and glass-ceramic matrices with ceramic or metallic fibres, advanced composite materials with improved mechanical properties can be fabricated. These composites were originally developed as model systems for laboratory-scale experiments. Due to their remarkable thermomechanical properties, however, the materials are candidate for a variety of technical applications. The present contribution is based on an extensive review of the available literature on these materials, accumulated in the last 30 years, focusing on manufacturing techniques. The literature analysis reveals that several challenges related to the composites fabrication remain for future developments. In particular, it is shown that relative limited R&D work has been carried out so far in the area of manufacturing of engineering components and structures having complex geometry and large dimensions. The application of electrophoretic deposition techniques in order to manufacture three-dimensional components, e.g. tubes, may represent a considerable improvement in this regard. The final goal of this report is to generate a broader interest in glass and glass-ceramic matrix composites both in the scientific and industrial communities, so that the high technological potential of these materials can be wider exploited.
A Novel Polyamide 12/Al-Cu-Fe Quasicrystal Composite
Authors: Liu Yuejian , Bloom Paul D. , Sheares Valerie V. , Otaigbe Joshua U. 
Published: April 2011

ABSTRACTThe tribological and mechanical properties of a novel polyamide 12 (PA12)/Al-Cu-Fe quasicrystal (QC) composite were systematically studied to accelerate efforts to develop a useful, melt-processable, and wear-resistant polymer composite. The wear and friction properties were characterized using a pin-on-disk configuration and the static and dynamic mechanical properties were investigated using dynamical mechanical analyzer, tensile tester, and an impact tester. Further, the melt processability of the composite was studied using a Haake torque rheometer and a dynamic rotational rheometer. The results suggest that PA12/QC composite can be melt-processed into a wear-resistant material with enhanced mechanical properties for applications where combinations of wear resistance and good mechanical properties are required. The static mechanical properties of the composite were found to be consistent with the Halpin-Tsai equation and agreement was observed between the measured viscoelastic properties and theoretical predictions of Burgers' and Eilers' models.
Molecular Engineered Porous Nanocomposites of Metal Oxide and Clay Using Surfactants
Authors: Zhu Huai Y. , Lu Gao. Q. 
Published: April 2011

ABSTRACTA novel synthesis route of metal oxide nanoparticles dispersed in a silicate framework is reported here. This composite nanostructure is highly thermally stable and porous, rendering large surface area and rich surface chemistry promising for catalytic applications. Aqueous solutions of metal salts were used as the precursors of the nanoparticles, and added in an aqueous dispersion of synthetic clay, laponite, in which the clay exists in exfoliated silicate sheets. Acid leaching of the clay sheets occurs in the reaction due to the strong acidity of the metal salt solution. Meanwhile, the metal hydrate ions polymerise because of the high pH of the clay dispersion and condense on the leached silicates. This mechanism is distinctly different from conventional pillaring process. The nanocomposites of various oxides and binary oxides were synthesised. By introducing polyethylene oxide surfactants, we obtained mesoporous nanocomposites with very large surface areas (400-900 m2/g) and porosity. These nanocomposites are superior catalysts or catalyst supports over of microporous pillared clays [1-3] due to their structure and surface properties.
Novel Synthesis of Aluminium Oxide Nanofibers
Authors: Zhu Huai. Y. , Lu Gao. Q. 
Published: April 2011

ABSTRACTThis report presents a novel synthesis method of alumina nanofibers at moderate conditions in aqueous systems through a surfactant-directed crystal growth process. In the presence of polyethylene oxide (PEO) surfactants, boehmite nanofibers of about 3 nm thick and 30-60 nm long formed from aluminium hydrate colloids. During the subsequent heating, the surfactant was evaporated and boehmite nanofibers were converted into γ-alumina nanofibers. The function of the PEO surfactant and the formation mechanism of the nanofibers are discussed. Alumina nanofibers are an ideal structural reinforcement for various nanocomposite materials. They are potential adsorbents with high adsorption capacity. Furthermore, their unique structure exhibits strong resistance to heating at high temperatures. The BET surface area of a typical sample after heating at 1200°C is as high as 68 m2/g. This makes the material very promising as excellent substrates for catalysts of high thermal stability.
Investigating Catalytic Properties of Composite Nanoparticle Assemblies
Authors: Maye M.M. , Luo J. , Lou Y. , Ly N. K. , Chan W.-B. , Phillip E. , Hepel M. , Zhong C.J. 
Published: April 2011

ABSTRACTWe present herein recent findings of an investigation of catalyst assembly and activation using metallic nanoparticles encapsulated with organic monolayers. Gold nanocrystals (2∼5 nm) encapsulated with thiolate monolayers assembled on electrode surfaces, were found to be catalytically active towards electrooxidation of CO and MeOH upon activation. The activation involved partial removal of the encapsulating thiolates and the formation of surface oxygenated species. A polymeric film was also used as a substrate for the assembly of the nanoparticle catalysts. When the polymer matrix was doped with small amounts of Pt, a remarkable catalytic activity was observed. These catalysts were characterized utilizing cyclic voltammetry and atomic force microscopy.
Surfactant Templated Assembly of Hexagonal Mesostructured Semiconductors Based on [Ge4Q10]4- (Q=S, Se) and Pd2+ and Pt2+ ions
Authors: Trikalitis Pantelis N. , Rangan Krishnaswamy K. , Kanatzidis Mercouri G. 
Published: April 2011

ABSTRACTMesostructured semiconducting non-oxidic materials were prepared by linking [Ge4Q10]4-(Q=S, Se) clusters with the square planar noble metal cations of Pd2+ and Pt 2+ in the presence of cetylpyridinium surfactant molecules. The use of Pt2+ afforded materials with exceptionally high hexagonal pore order similar to those of high quality silica MCM-41. These materials are semiconductors with energy band gap in the range 1.8<Eg<2.5 eV.
Intercalative Route to Heterostructured Nanohybirds
Authors: Choy Jin-Ho 
Published: April 2011

ABSTRACTWe have successfully synthesized organic-inorganic and bio-inorganic nanohybrids by applying an intercalation technique systematically to Bi-based cuprate superconductors, Bi2Sr2Cam-1CumOy(m = 1, 2, and 3; BSCCO), and to layered double hydroxides(LDHs), those which are of high importance in terms of basic understanding of intercalation reactions and of their practical applications. The organic-inorganic hybrids were achieved via intercalative complexation of iodine intercalated BSCOO with organic salt of Py-CnH2n+1I (Py = pyridine). The high-Tcsuperconducting intercalate with its remarkable lattice expansion can be applied as a precursor for superconducting colloids when dispersed in an appropriate solvent. We were also able to demonstrate that the biomolecules stabilized in the interlayer space of LDH retain their chemical and biological integrity. If necessary, LDH, as a reservoir, can be intentionally removed by dissolving it in an acidic media or interlayer biomolecules in LDH can be released via ion-exchange reaction in electrolyte. It is, therefore, concluded that the inorganic LDH can play a role as a good host lattice for gene reservoir or carrier.
Soft reverse current-voltage characteristics in V2O5 nanofiber junctions
Authors: Kim Gyu-Tae , Muster Jörg , Burghard Marko , Roth Siegmar 
Published: April 2011

ABSTRACTV2O5 nanofibers showed the rectifying current-voltage characteristics under an asymmetric contact configuration at room temperature, indicating the formation of a Schottky diode. The ideality factors as a Schottky diode were estimated to be 6.1 at the forward bias and 1.4 at the reverse bias. The larger current at the reverse bias defined by the negative voltage at the metal electrode may originate from the contribution of the tunneling via field emission or thermionic field emission. The ultimate geometric size of nanofibers enhances the influence of the tunneling mechanism and modifies the nano-scale Schottky diode, requiring more understanding in designing the nano-scale electronic devices with the metal contacts.
Growth of Solid and Hollow Nanowhiskers from Nanoscale Powders
Authors: Malkhasyan R.T. , Karakhanyan R.K. , Nazaryan M.N. 
Published: April 2011

ABSTRACTThe fast mass growth of solid and hollow nanowhiskers of MoO3 and WO3 is obtained owing to the heating of the nanoscale powders of these materials by means of electron beam. Based on our transmission electron microscopic observation the growth mechanism of the MoO3 and WO3 nanowhiskers is proposed.
The Generation of a Carbon Nanotube- Cyclodextrin Complex
Authors: Farrell G.F. , Chambers G. , Dalton A.B , Cummins E. , McNamara M. , Baughman R.H. , Panhuis M. in het , Byrne H.J. 
Published: April 2011

ABSTRACTIn this study the intermolecular interactions of small diameter (∼0.7nm) carbon nanotubes and γ-cyclodextrin were examined. Four samples of γ cyclodextrin and HiPco carbon nanotubes were prepared. The first, by grinding the tubes and the cyclodextrin (1:30 ratio) together in a dry mixture, the second was prepared in a similar fashion but was ground in the presence of water (1ml). Finally an aqueous solution of γ-cyclodextrin (0.3M) and HiPco carbon nanotubes (5mg) was prepared by refluxing for ∼100 hours, forming a pale yellow solution from which a number of crystals were produced, both the solution and the recrystallised material were analysed. The samples were analysed using UV-Vis-NIR and Raman spectroscopy. The results presented are the first spectroscopic evidence of an intermolecular interaction between γ-cyclodextrin and single wall nanotubes.
Self-Assembly of Metal Nanoclusters in Block Co-Polymers
Authors: Tadd Erica H. , Bradley John , Goldberg Eugene P. , Tannenbaum Rina 
Published: April 2011

ABSTRACTThis paper describes the formation of cobalt and iron metal nanoclusters in various polymeric domains. The size of the particles, their size distribution and their geometry is controlled by the extent of the interfacial interactions between the polymeric phase and the growing metal fragments. Iron oxide particles are shown to exhibit various geometries as a function of the polymer medium and the temperature at which they are formed. The selective phase separation and particle confinement of cobalt clusters in the presence of PS25300-b-PMMA25900 block co-polymer was achieved due to the different reactivities of the functional groups in the blocks towards the metal fragments. Transmission electron micrographs showed that cobalt clusters aggregated primarily in the poly(methyl methacrylate) block, while no cobalt nanoclusters were observed in the polystyrene block, thus creating a patterned distribution that coincided with the morphology of the block copolymer.
Multi-functionalization Of Silicon By Nanoparticles Through “Plug and Play” Approach
Authors: Prabhakaran K. , Shafi K.V.P.M. , Ulman A. , Ogino T. 
Published: April 2011

ABSTRACTIn this paper, we demonstrate a “Plug and Play” approach, whereby externally synthesized nanoparticles of desired functions and size are incorporated into the semiconductor, followed by the manipulation of surface chemical bonds in order to achieve multiple functionality. Sonochemically synthesised Fe2O3 nanoparticles were introduced onto device quality Si wafers. On annealing the particle-treated Si wafer in ultra high vacuum, oxygen changes the bonding partner from Fe to Si and desorb as SiO at ∼ 760°C, leading to the formation of uniform sized Fe nanoparticles ( size ∼6-8 nm) on the surface and the sample shows ferromagnetic behaviour. More importantly, the particle treated Si exhibits light emission at wavelengths 1.57, 1.61 and 1.65 microns (full width at half maximum ∼ 20 meV). Emission in this wavelength range is crucial for optical communications and is highly desired from a Si based material. Further, oxidation of this material leads to the formation of a selective capping layer of SiO2. Thus, by manipulating the surface chemical bonds, we are able to introduce optical, magnetic, metallic and insulating functions to Si. Additionally, the particles exhibit self-assembly on a patterned Si surface. We believe that this approach is universal and the material developed here is compatible with the planar Si technology, bringing us closer to realization of Si based monolithic electronics.