Density of Wood
Perhaps the single most important property controlling the mechanical performance of a piece of wood is its density. Density is the ratio of mass to volume.
Materials Literature
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Atomic Structure of Monolayer Graphite Formed on Ni(111).
The atomic structure of monolayer graphite formed on a Ni (111) surface was investigated by means of LEED intensity analysis. We measured the I-V curves of the (1, 0), (0, 1) and (1, 1) diffraction spots from a 1×1 atomic structure, and analyzed them by using the Van Hove's analytical program based on dynamical theory…
Large Enhancement of Electrical Conductivity in Magnesium Phosphate Glasses by Ion Implantation of Proton
(1) D. C. conductivity of Mg(PO3)2 glasses at room temperature was drastically enhanced from -1015S·cm-1 to -5×10-4S·cm-1 and the activation energy of the conduction was greatly reduced from 1.1eV to 0.18eV upon implantation of 120keV H+ to a fluence of 1×1018cm-2. Almost the same changes in conductivities and the act…
XPS analysis of fluorinated polyimides
Five different fluorinated polyimides were characterized using X-ray photoelectron spectroscopy (XPS). Elemental compositions and polyimide stoichiometries as elucidated with XPS are reported. The fluorinated polyimides derived from corresponding poly(amic acid)s were completely imidized after thermal cure at 350°C, g…
Transport and optical properties of PbTe1−xSx (x = 0.02 and x = 0.05) mixed crystals
Abstract Far‐infrared and Raman scattering spectra as well as galvanomagnetic measurements of PbTe 1− x S x ( x = 0.02 and 0.05) mixed crystals in the temperature range from 10 to 300 K are presented. The far‐infrared reflectivity spectra are analysed using a fitting procedure based on the plasmon‐phonon interaction m…
Carbothermal reduction of sillimanite
Preliminary studies on the carbothermal reduction of sillimanite (Al2O3SiO2) powders are reported. The effects of various reaction parameters, e.g. reaction temperature (1550–1700 °C), C: Si molar ratio (4.5–9.0) in the reactant mixtures, the nature and source of carbon (carbon black or activated charcoal) and the rea…
Stereometrical X‐ray Interferometric Diffraction Topography of Crystal Imperfection
Abstract A method for X‐ray interferometric investigation of the deformation field of crystal imperfections by means of double and triple interferometers is proposed. It is shown experimentally that by means of double and triple interferometers it is possible to detect segregation lines, displacement lines, and the Mo…
A Simplified Approach for Modeling Fatigue of Unidirectional Ceramic Matrix Composites
An analytical methodology is developed to model the response of unidirectional ceramic matrix composites (CMCs) under monotonic and fatigue loadings at room temperature. The analysis is presented as a first step toward analyzing the fatigue behavior of CMCs at elevated temperatures. The laminate is modeled using a mod…
Fundamental Defect Centers in AlPO4-5 and VPI-5 Molecular Sieves
For the first time, the formation of paramagnetic defect centers in AlPO 4 molecular sieves has been monitored by electron spin resonance (ESR) spectroscopy. Results from ESR measurements demonstrate that the structural defects in hydrated AlPO 4 -5 and VPI-5 molecular sieves change into paramagnetic defect centers wh…
Spectroscopic and Transport Properties of (NH4)2CuCl4 · 2 H2O Single Crystal
Abstract Electron paramagnetic resonance (EPR), Optical absorption and Transport properties of (NH 4 ) 2 CuCl 4 2 H 2 O single crystals have been studied. An anisotropic g tensor was observed with gl = 2.241 and g∥ = 2.081 by EPR method. The spin orbit coupling constant is found to be 540 cm −1 . The optical absorptio…
Fluorescence quenching and complexation behaviour of tetraphenylporphyrin with some divalent metal ions
The fluorescence quenching and complexation behaviour of tetraphenylporphyrin (TPP) have been studied using fluoresence, electronic absorption spectra and the stopped-flow technique. The second-order fluorescence quenching rate constant (kq) increases in the order Ni2+ > Co2+ > Hg2+ > Sn2+ in methanol. Both Ni2+ and C…
Modelling of Growth Rate for MSMPR Crystallizer Data
Abstract One of the most important applications of the population balance approach to MSMPR crystallizer modelling is the recovery of crystal nucleation and growth rates data from steady‐state crystal size distributions (RANDOLPH, LARSON). A large number of studies have confirmed that both size‐dependent (growth rate…
HCN Synthesis by Ammoxidation of Methane and Ethane on Platinum Monoliths
We have examined HCN synthesis by the ammoxidation of CH 4, C 2 H 6, and CH 4 /C 2 H 6 mixtures in air or O 2 at atmospheric pressure on α-Al 2 O 3 foam monoliths coated with 1−10 wt % Pt and on Pt−10% Rh gauzes. The HCN reaction system was found to be highly sensitive to the catalyst microstructure because we observe…
Use of the Lognormal Distribution Function To Describe Orientational Relaxation in Optically Nonlinear Polymers
Second harmonic generation decay has been used to follow the orientational relaxation of dipolar chromophores either dissolved in (guest−host) or chemically attached to (side chain) an amorphous polymer host. The guest−host system investigated is the chromophore lophine-1 in a polyimide host and the side-chain system…
Preparation of a Langmuir–Blodgett film of a platinized viologen-linked porphyrin and photoinduced hydrogen evolution
A Langmuir–Blodgett film of a platinized viologen-linked porphyrin is prepared, and steady photoinduced hydrogen evolution is observed with the porphyrin under steady-state irradiation.
Self-Consistent Theory of Block Copolymers with Conformational Asymmetry Vol. 26, Number 25, December 6, 1993, pp 7070−7075
ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionSelf-Consistent Theory of Block Copolymers with Conformational Asymmetry Vol. 26, Number 25, December 6, 1993, pp 7070−7075J. D. Vavasour and M. D. WhitmoreCite this: Macromolecules 1996, 29, 15, 5244Publication Date (Web):July 15, 1996Publication History Published o…
Chemical Study of Indonesian Medicinal Plants
A series of scientific expeditions in Indonesia for collecting informations and materials concerning locally used medicinal plants and Javanese traditional medicine "jamu" have been carried out by us since 1985. This article reviews pharmacochemical investigations of nine Indonesian medicinal plants: i.e. Pongamia pin…
Crystal Structure and Magnetic Properties of R<SUB>2</SUB>(Fe, M)<SUB>17+δ</SUB>
We discovered a novel compound expressed by R2(Fe, M)17+δ in the compositional rangc between 2-17 and 1-12. Hong-Shou Li et al. reported R3(Fe, M)29 which is stoichiometric compound with monoclinic structure. These compounds show similar X-ray diffraction patterns.In this paper, syntheses of R2(FC, M)17+δ were attempt…
X‐ray diffraction and TGA studies on annealed PPT twaron fibers and powder
Abstract Twaron fiber is spun from the polymer poly(paraphenylene terephthalamide), PPT, and has a crystallinity of 82%. Wideangle X‐ray diffraction, combined with the multipeak resolution procedure, was applied to study the changes in the structure after annealing the fiber in the temperature range of 100–675°C. The…
Factors Affecting Polyhydroxybutyrate Biosynthesis In the Marine Photosynthetic Bacterium Rhodopseudomonas sp. Strain W-1 S
A marine photosynthetic bacterium Rhodopseudomonas sp. strain W-1S, accumulated polyhydroxybutyrate (PHB) to 56% of the dry cell weight under microaerobic and photoheterotrophic conditions. The addition of NaC1 and phosphate was essential for the accumulation. Acetate was the best carbon source for PHB accumulation, w…