Synthesis of Quadruply Carbon-13 Labeled Tetramethyltetrathiaful Valene
A short synthesis of tetramethyltetrathiafulvalene quadruply labeled with carbon-13 is described.
Materials Literature
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Molecular-dynamics study of phase transitions in alkali thiocyanates
An account is presented of our studies of the order-disorder phase transitions in KSCN, RbSCN, and CsSCN. These are based on parameter-free interionic potentials based on the Gordon-Kim modified electron gas formalism extended to molecular ions. We performed static structural relaxations and supercell molecular dynami…
Effects of Gamma Radiation on Various Polyimides
Abstract Four polyimides (PIa‐PId) containing 4,4′‐hexafluoroisopropylidene‐bisphthalic anhydride (6FDA) units in the backbone were prepared via one‐step synthesis. The effects of different doses of gamma radiation from a cobalt‐60 source are studied. The irradiated and the unirradiated polyimides are characterized by…
Understanding Electrochemical Thermodynamics through Entropy Analysis
This discovery-based activity involves entropy analysis of galvanic cells. The intent of the activity is for students to discover the fundamentals of electrochemical cells through a combination of entropy analysis, exploration, and guided discovery. The student is guided into discovering (i) two fundamental quantities…
Synthesis and Crystal Structure of New Ternary Chalcogenides of Group IV Metals: K2ZrS4, Rb2ZrS4, and Rb2HfS4
Abstract The new ternary one-dimensional chain compounds K 2 ZrS 4 , Rb 2 ZrS 4 and Rb 2 HfS 4 were prepared at 350 °C by reacting A 2 S 3 and S with elemental M (A = K, Rb; M = Zr, Hf). They are isostructural, crystallizing in the orthorhombic space group Pbca with Z = 8 . The M atoms are in a distorted octahedral en…
A new stacking motif: complex alloy structures interpreted as modulated structures
The structures of lambda-Al4Mn, manganese aluminide, kappa-Al177Cr49Ni, chromium nickel aluminide, and epsilon-Al4Cr, chromium aluminide, which have been described in terms of the aggregation of clusters until now, are interpreted as modulated structures. They are basically composed of close-packed layers with ordered…
Thermal stress analysis for polyimide thin film and a substrate layer system
We propose an analytical model based on Timoshenko's theory which describes chemical and physical properties of a polymer and a substrate layer system. This temperature dependent model is developed to account for the thermal stress caused by a mismatch of isobaric expansivity, due to the solvent evaporation and imidiz…
Hot corrosion in a temperature gradient
Hot corrosion is the accelerated attack of materials at elevated temperatures that is induced by a thin film of fused salt. Many materials that experience hot corrosion are exposed to high heat fluxes and temperature gradients. The hot corrosion of metals can be described by the dissolution of a protective metal oxide…
Mutual diffusion at polystyrene/poly(vinyl methyl ether) as measured by ATR-FTIR and rheometry
Mutual diffusion at PS/PVME (polystyrene/polyvinyl methyl ether) interface both below and above the glass transition temperature, Tg, of polystyrene was probed by Attenuated total reflection (ATR) and rheometry techniques. The results were analyzed with a simple three layer model and a combination of Fickian and Case-…
The Multi-fluid Multi-phase Subchannel Analysis Code KAMUI for Subassembly Accident Analysis of an LMFR
A computer program KAMUI has been developed to simulate multi-dimensional thermal-hydraulic behaviors of the coolant and disrupted fuels in a subassembly under hypothetical accident conditions of a Liquid-Metal Fast Reactor (LMFR) where the strong momentum and thermal coupling of the coolant flow dominates the materia…
The influence of microstructure on the fracture toughness of AISI M2 high-speed steel
When modelling the fracture toughness of the investigated AISI M2 high-speed steel, the stress-modified critical strain criterion was used. The very important influence of microstructural parameters such as the volume fraction of undissolved eutectic carbides, their mean diameter, and the mean distance between the car…
The Reaction‐Bonded Aluminum Oxide (RBAO) Process: II, The Solid‐State Oxidation of RBAO Compacts
The oxidation kinetics and the fraction of aluminum that is oxidized via solid–gas reaction in reaction‐bonded aluminum oxide (RBAO) compacts are shown to be strongly dependent on the oxidation temperature and the characteristics (size and green density) of the RBAO compact. Based on the Biot number, the oxidation pro…
Electron diffraction study of octagonal-cubic phase transitions in Mn-Si-Al
We report the observation of two kinds of octagonal-cubic transition to either the \ensuremath{\beta}-Mn-type structure or the ${\mathrm{Mn}}_{3}\mathrm{Si}$ crystal following annealing Mn-Si-Al octagonal quasicrystal at different heating speeds. A theoretical analysis has been given and the simulated diffraction patt…
Diatoms on the cirri of tropical barnacles
Two species of large extension feeding barnacles are abundant on exposed tropical rocky shores of northern Australia. The cirri of many specimens carry varying numbers of a commensal diatom in some cases with as many as 2000 individuals on a single cirrus. The araphid diatom resembles the genus, Lichmophora within the…
Applications of Genetic Algorithms in Cluster Optimisation
Applications of Genetic Algorithms for optimisation of atomic clusters are reported. It is shown that the genetic algorithms are very useful tools for determining the minimum energy structures of clusters of atoms described by interatomic potential functions containing up to a few hundred atoms. The algorithm generall…
Properties of a bacterium which degrades solid poly(tetramethylene succinate)-co-adipate, a biodegradable plastic
Various microorganisms were screened for their ability to degrade poly(tetramethylene succinate)-co-(tetramethylene adipate) (PBSA). Strain BS-3, which was newly isolated from a soil sample, was selected as the best strain. From taxonomical studies, the strain was tentatively ascribed to belong to the genus Acidovorax…
BOLEITE: RESOLUTION OF THE FORMULA, K Pb26 Ag9 Cu24 Cl62 (OH)48
Abstract The crystal structure of boleite, K Pb26 Ag9 Cu24 Cl62 (OH)48, a 15.288(2) Å, V 3574(1) Å3, Pm 3̅m, Z = 1, has been refined to an R-index of 2.2% based on 884 observed (5σ) reflections collected with MoKα X-radiation. A new site was resolved, and site-scattering refinement showed it to be occupied by a scat…
Single Crystal Raman Scattering, Powder Infrared Spectroscopy and Thermal Properties of Rubidium Hydrogen Tartrate
Single crystals of rubidium hydrogen (+)-tartrate [RbH(C4H4O6)] (RbHT) were grown by slow evaporation of an aqueous solution at room temperature. The crystals have been studied by Raman scattering; infrared transmittance at room temperature was measured on powder samples. Tentative assignments have been made for both…
Biodegradation of poly(vinyl alcohol) with different molecular weights and degree of hydrolysis
The biodegradability of poly(vinyl alcohol) (PVA) was investigated under different conditions by respirometric determinations, iodometric analysis, and molecular weight evaluation. Microbial inocula derived from the sewage sludge of municipal and paper mill wastewater treatment plants were used. A rather active PVA-de…
Synthesis and characterization of a novel chitosan‐based network prepared using naturally occurring crosslinker
Novel chitosan-based polymeric networks were synthesized and characterized by FTIR, UV and C13 NMR. A naturally occurring crosslinking reagent—genipin, which has been used in herbal medicine and in the fabrication of food dyes, was used to prepare crosslinked chitosan hydrogel. The heterocyclic compound of genipin cro…