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Standardisierte Texturmessung / Standardized Measuring of Textures

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Patente / Patents

Crystal Structure of a Sodium Sorption Complex of Zeolite X Containing Linear Na32+Clusters

An anhydrous single crystal of sodium zeolite X, Na 92 Si 100 Al 92 O 384, was exposed for 48 h to Na vapor at 225 °C. Its structure was determined by X-ray diffraction methods in the cubic space group Fd 3̄; a = 25.100(11) Å at 22 °C; R 1 = 0.071 and R 2 = 0.088 for the 544 reflections for which I > 3σ( I ). A total…

Conducting Polymer Color Sensor

A color sensor device using conducting polymer poly(3-hexylthiophene) (PAT6), has been fabricated and characterized. The device consists of two photocells made of the same conducting polymer with different polymer thicknesses, and which exploits the difference in the photocurrent spectrum of the photocells. The color…

A Processable Mullite Precursor Prepared by Reacting Silica and Aluminum Hydroxide with Triethanolamine in Ethylene Glycol: Structural Evolution on Pyrolysis

A simple, processable precursor to mullite can be synthesized in quantities of 100 g in a few hours by direct reaction of silica, aluminum hydroxide, and triethanolamine in ethylene glycol. To delineate a processing window whereby precursor shapes can be transformed into mullite, the chemical and phase microstructural…

Crystal Structures of Dehydrated Fully Mn2+-Exchanged Zeolite X and of Its Ethylene Sorption Complex

The crystal structures of dehydrated Mn 46 Si 100 Al 92 O 384 ( a = 24.721(5) Å) and of its ethylene sorption complex Mn 46 Si 100 Al 92 O 384 ·30C 2 H 4 ( a = 24.690(5) Å) have been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd 3̄ at 21(1) °C. Each crystal was prepared by dehyd…

The concept of cohesional entanglement

Abstract A concept of cohesional entanglement through local nematic interaction of neighboring chain segments has been introduced in addition to the usual topological entanglement of chains. As topological entanglement is important to properties of the polymer in the rubbery and flowing states at temperatures well abo…

Experience and assessment of stress corrosion cracking in L-grade stainless steel BWR internals

The stress corrosion cracking (SCC) rate of reactor internals of boiling water reactors (BWR) continues to increase with on-line operating years. The recent occurrences of cracking in the weld heat affected zones of high carbon stainless steel core shrouds correlate with the years of operation and the water chemistry…

Antiulcer activity of naturally occurring pyrano-coumarin and isocoumarins and their effect on prostanoid synthesis using human colonic mucosa.

Oral administration of bergenin and norbergenin, two isocoumarins, isolated from the leaves and roots of Flueggea microcarpa and luvangetin, a pyranocoumarin isolated from the seeds of Aegle marmelos Correa, showed significant protection against pylorus-ligated and aspirin-induced gastric ulcers in rats and cold restr…

Theory of color symmetry for periodic and quasiperiodic crystals

The author presents a theory of color symmetry applicable to the description and classification of periodic as well as quasiperiodic colored crystals. This theory is an extension to multicomponent fields of the Fourier-space approach of Rokhsar, Wright, and Mermin. It is based on the notion of indistinguishability and…

Viscoelastic model of phase separation

We show here a general model of phase separation in isotropic condensed matter, namely, a viscoelastic model. We propose that the bulk mechanical relaxation modulus that has so far been ignored in previous theories plays an important role in viscoelastic phase separation in addition to the shear relaxation modulus. In…

Surface-Enhanced Raman Spectroscopy of Crystal Violet in the Presence of Halide and Halate Ions with Near-Infrared Wavelength Excitation

The interaction of crystal violet (CV) with halide, halate ions, and pyridine and the interaction of CV with colloidal silver surface have been studied by surface-enhanced Raman spectroscopy (SERS) with near-infrared (NIR) excitation. Cl -, Br -, I -, and BrO 3 - ions as well as pyridine give rise to a large enhanceme…

Measurement of crystalline index in nylons by DSC: Complexities and recommendations

Differential scanning calorimetry (DSC) is one of the most widely used technique for measuring crystallinity in the polymer industry. The major source of error in the crystalline index (CIDSC) of low crystallinity polymeric articles, is the development of further crystallinity during the DSC scan. Although, this type…

Comparison of Zn_{1-x}Mn_xTe/ZnTe multiple-quantum wells and quantum dots by below-bandgap photomodulated reflectivity

Large-area high density patterns of quantum dots with a diameter of 200 nm have been prepared from a series of four Zn_{0.93}Mn_{0.07}Te/ZnTe multiple quantum well structures of different well width (4 nm, 6 nm, 8 nm and 10 nm) by electron beam lithography followed by Ar+ ion beam etching. Below-bandgap photomodulated…

First-principles and semiempirical calculations forFcenters inKNbO3

The linear muffin-tin orbital method combined with density functional theory (local approximation) and the semiempirical method of the intermediate neglect of the differential overlap (INDO) based on the Hartree-Fock formalism are used for the study of the $F$ centers (O vacancy with two electrons) in cubic and orthor…

THE PHYSICAL AND CHEMICAL PROPERTIES OF ULTRATHIN OXIDE FILMS

Thin oxide films (from one to tens of monolayers) of SiO2, MgO, NiO, Al2O3, FexOy, and TiO2 supported on refractory metal substrates have been prepared by depositing the oxide metal precursor in a background of oxygen (ca 1 x 10(-5) Torr). The thinness of these oxide samples facilitates investigation by an array of su…

Cellulose Microcrystal Film of High Uniaxial Orientation

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTCellulose Microcrystal Film of High Uniaxial OrientationNishiyama Yoshiharu, Kuga Shigenori, Wada Masahisa, and Okano TakeshiView Author Information Laboratory of Structural Biopolymers, Department of Biomaterial Sciences, Graduate…

Protein—protein crystal‐packing contacts

Protein-protein contacts in monomeric protein crystal structures have been analyzed and compared to the physiological protein-protein contacts in oligomerization. A number of features differentiate the crystal-packing contacts from the natural contacts occurring in multimeric proteins. The area of the protein surface…

Effect of Porosity and Microstructure on the Strength of Si 3 N 4 : Designed Microstructure for High Strength, High Thermal Shock Resistance, and Facile Machining

The flexural strength of porous Si 3 N 4 ceramics with a variety of microstructures and porosities were evaluated, and the effect of microstructure on the flexural strength was investigated to obtain machinable Si 3 N 4 ceramics having both high strength and high thermal shock resistance. Porous Si 3 N 4 having three…