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The Effect of the Chemical Metamerism Polyolefin on the Friction and Wear of Bronze Powder Filled High Density Polyethylene

Effect of doped and undoped POMA on the morphology and miscibility of blends with Poly(vinylidene fluoride) (PVDF)

The effect of the addition of small amounts of doped and undoped poly(o-methoxyaniline) (POMA) on the morphology of melt crystallized PVDF was investigated by means of polarized light optical microscopy. Undoped POMA (POMA-EB) inhibits nucleation and growth of non ringed spherulites, partially formed by the polar gpha…

Vanadium characterization in BTO: V sillenite crystals

Visible and Infrared Optical Absorption and Electron Paramagnetic Resonance (EPR) techniques have been used to characterize the intrinsic defects in sillenite type crystals: nominally pure Bi12TiO20 (BTO) and doped with vanadium (BTO:V). Optical quality crystals, with the composition Bi12.04±0.08Ti0.76±0.07V0.16±0.02O…

Brazing of Silicon Nitride with Reactive Filler Metals

Influence of the Electric Field on the Electrorheological Behaviour of Crystalline Cellulose Suspensions in Silicone Oils

This work deals with electrorheological (ER) behaviour of moist crystalline cellulose dispersed in silicone oils of different viscosities (0.1, 0.35 and 1.0 Pa.s) in DC and 50 Hz AC electric fields. The experiments were performed on a parallel-plate viscometer with various width of the gap. In the AC field the intensi…

Strained In1-xGaxAsyP1-y/InP quantum well heterostructures grown by low-pressure metalorganic vapor phase epitaxy

We have investigated the optical and the structural properties of strained In1-xGaxAsyP1-y/InP and strain compensated In1-xGaxAsyP1-y/In1-zGazAsqP1-q/InP multi-quantum well heterostructures grown by low-pressure metalorganic vapor phase epitaxy at different growth conditions. Our results indicate an increase of the co…

Pure Material Instability and the Concept of Yield Stress

The paper is concerned with the rheological study of gels, complex materials which are characterised by an internal network structure developed in viscous liquids. This category of materials exhibits in viscometric motion a yield state at a critical value of the applied shear stress. The yield shear stress defines the…

30 Years of Progress in Viscometers and Rheometers

The history of commercial viscometry and rheometry over the last thirty years is summarised. In terms of those instruments that have established themselves in a lasting position in the field, we highlight the importance of a sound original idea, good marketing, and constant improvement as technology advances. Instrume…

Nanocrystalline magnetic materials obtained by flash annealing

The aim of the present work was to produce enhanced-remanence nanocrystalline magnetic material by crystallizing amorphous or partially amorphous Pr4.5Fe77B18.5 alloys by the flash annealing process, also known as the dc-Joule heating process, and to determine the optimal conditions for obtaining good magnetic couplin…

Influence of process conditions on hydroxyapatite crystallinity obtained by direct crystallization

Crystallization from solutions was applied to produce stoichiometric and crystalline hydroxyapatite (HAP) suitable for use as a biomaterial. This was accomplished by keeping a low supersaturation through the following procedure: semi-continuous operating mode, slow reactant addition rate and addition of a calcium comp…

Crystallization study of SrTiO3 thin films prepared by dip coating

In this study, the crystallization process of SrTiO3 thin films, prepared by a chemical method, was characterized by Fourier Transformed Infra Red (FT-IR), Grazing Incident X-ray Diffraction (GIXRD), Thermal Analysis (TG) and X-ray Absorption Near Edge Structure (XANES). The results showed that an amorphous inorganic…

STRUCTURAL COMPOSITE LAMINATES OPTIMISATION CYCLE COUPLED WITH A COMPUTER AIDED MANUFACTURING PROCESS: AN APPLICATION INTO RESIN TRANSFER MOULDING TECHNOLOGY

Iodo-oxyapatite, the first example from a new class of modulated apatites

Iodo-oxyapatite [pentadecacalcium iodide oxide nonaphosphate, Ca(15)(PO(4))(9)IO] was synthesized by a flux method and the structure was solved from single-crystal X-ray data. The crystal structure was refined in the space group P6(3)/m [a = 9.567 (1), c = 20.754 (2) Å and Z = 2] to wR on F of 0.0459. Iodo-oxyapatite…

Atomistic Simulations for Multiscale Modeling in bcc Metals

Quantum-based atomistic simulations are being used to study fundamental deformation and defect properties relevant to the multiscale modeling of plasticity in bcc metals at both ambient and extreme conditions. Ab initio electronic-structure calculations on the elastic and ideal-strength properties of Ta and Mo help co…

Dimensional Changes in Knitted Silk and Cotton Fabrics with Laundering

Deformation by laundering is investigated for single jersey and 1 × 1 rib flat knit silk and cotton fabrics with yams of varying linear densities and fabric tightness. The fabrics are subjected to relaxation processes and an extended series of wash and tumble- dry cycles. Changes in dimensions are measured in every pr…

SYNCHROTRON RADIATION SCANNING PHOTOEMISSION MICROSCOPY: INSTRUMENTATION AND APPLICATION IN SURFACE SCIENCE

X-ray photoelectron spectroscopy has become a true microscopic technique at third generation soft X-ray synchrotron sources, finding applications in many domains of academic and applied research. This paper describes the present status of scanning photoemission microscopy, where by using photon optics the photon beam…

Optimization of mercuric iodide platelets growth by the polymer controlled vapor transport method

Mercuric iodide crystals in their platelet habit were grown by the polymer controlled vapor transport method. Mercuric iodide 99% in purity was sublimated at temperatures about 122 - 126 °C and vacuum conditions (10-5 mmHg), after selecting an appropriate polymer. Temperature profiles and experimental heat transfer mo…

Vibrational Spectroscopy and Dehydroxylation of Aluminum (Oxo)Hydroxides: Gibbsite

The infrared absorption, infrared emission, and Fourier transform (FT)-Raman spectra of a series of gibbsites well defined by X-ray diffraction have been obtained. Hydroxyl stretching frequencies were found ∼ at 3670, 3620, 3524, 3452, 3395, 3375, and ∼ 3300 cm −1 . Hydroxyl deformation vibrations were observed at 105…

Anharmonicity and localization of atomic vibrations in vitreous silica

A numerical analysis has been made of anharmonicity effects for vibrational eigenmodes in a model of vitreous silica constructed by molecular dynamics. It is shown that in macroscopic systems all eigenmodes are generally harmonic. Strong anharmonicity is found for the bare localized modes in the low-frequency region a…