Materials Literature
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We measured Raman spectra of diamonds in ureilite meteorites and of diamonds synthesized under static high pressure, under shock-induced high pressure, and by chemical vapor deposition. The full width at half maximum (FWHM) and wavenumber position of a Raman line of F2g (at 1332 cm−1) are compared. Both the wavenumber…
In order to investigate the physical basis of protein stability, two mutant L-lactate dehydrogenases (LDH) and the wild-type enzyme from Bacillus megaterium were analyzed for differences in quaternary structure, global protein conformation, thermal stability, stability against guanidine hydrochloride, and polypeptide…
Several thallium(III) porphyrin complexes [Tl(por)X] with the axial ligand x = MeCO2, CF3CO2, Cl, Br, l, CN, SCN or N3, have been obtained via ligand-exchange reactions from the corresponding thallium(III) trifluoroacetates. All compounds were characterized by 1H NMR, UV/VIS spectroscopy, and elemental analysis. Fourt…
Selectively O-alkylated inositols of myo-, scyllo- and chiro-configuration allow detailed studies of the relationship between the substitution pattern in the cyclohexane ring and the liquid crystalline properties observed to be made for these mainly novel cyclic compounds containing hydroxyl functions. The types of th…
PTFE foils were plasma-treated in order to enhance their adhesion to thin films. The effect of plasma treatment using argon and oxygen discharge gases on the surface energy of PTFE foils was examined by measuring the contact angles of water droplets placed on the foil surface. Exposure to the plasma for only about 10-…
Tone sind unverfestigte Sedimentgesteine. Sie bestehen im wesentlichen aus Mineralpartikeln kleiner 20 μm im Durchmesser. Unter diesen Partikeln herrschen blättchenförmige silicatische Tonminerale mengenmäßig vor, deren Teilchendurchmesser meistens kleiner als 2 μm sind. Altersmäßig gehören die unverfestigten Tone fas…
Synchrotron radiation has been used extensively to overcome a variety of technical challenges involved in data collection from macromolecular crystals. The next generation of such sources offer a higher brilliance at much shorter wavelengths than hitherto available. Hence, the quality of X-ray diffraction data from cr…
The possibility of using the Vicat softening-point test as an additional method to find the phase behaviour of amorphous polymer blends is discussed. The comparison of the TgS by DSC to the Vicat temperatures of three blends, miscible, immiscible and partially miscible, allows us to interpret the different Vicat softe…
Abstract The methylated metallocenes (MeCp) 2 M with M = V, Cr, Mn, Co, Ni (1–5) were investigated by 1 H and 2 H NMR spectroscopy at natural abundance. The 2 H NMR signals are narrower by a factor of up to 30 compared with the corresponding 1 H NMR signals, thus establishing an inexpensive method and a general improv…
Description 12 peer-reviewed papers provide practical information on the selection and use of wear tests in engineering. Includes guidance in deciding how to test for wear of new materials or design; actual examples of successful wear testing; and suggested approaches by experts.
Description Addresses current issues related to fatigue and fracture of composites and practical insights on new developments in damage and failure analysis and test methods. Provides new directions for emerging technology areas, such as micro mechanics and interfacial analysis, which are applicable to fatigue and fra…
The optical properties of Er3+ ions doped in aluminate glasses were investigated.(1) Among three intensity parameters obtained from absorption spectra by Judd-Ofelt theory, Ω2 and Ω4 showed a large value compared with those in other oxide glasses.(2) The multiphonon decay rates of the 4S3/2 and 4F9/2 levels were obtai…
Two mutants of adenylate kinase from Escherichia coli have been crystallized and analyzed by X-ray diffraction at resolutions of 3.4 and 2.4 A, respectively. These mutants are Pro-9-->Leu and Gly-10-->Val. They were selected for their positions in the highly conserved Gly-loop forming a giant anion hole for the beta-p…
The influence of elevated copper concentrations on cell numbers and extracellular protein production was investigated in chemostat cultures of Vibrio alginolyticus. High (20 microM) copper in the medium reservoir resulted in a dramatic drop in cell numbers which was overcome with time. The copper-stressed cultures est…
Abstract The initial oxidation behaviour of a Co–20%Ni alloy exposed to air and the longer term oxidation of a metalevaporated magnetic recording tape (MET) of the same composition have been studied using XPS and AES. Air exposure of the alloy for 24 h showed the formation of a mixed hydroxide/carbonate layer over a r…
The brittle-ductile transition (BDT) in precracked Si and other pure covalent crystals is associated with plastic relaxation processes induced by the crack tip stress field. A model which simulates the dynamic behaviour of shielding dislocations near a crack tip under an increasing stress has been developed. Dislocati…
The mixed perovskite La2CuTiO6 has been prepared using several methods (classical ceramic, oxide precursors and sol–gel) in order to study the distribution of Cu and Ti in the lattice. This perovskite has an orthorhombically distorted structure [Pnma, standard group no. 62, a= 5.6262(6)Å, b= 7.8396(8)Å, c= 5.5702(6)Å,…
Singlet excited-state properties of mono- and di-thiaporphyrins and their dications are reported. A comparison of vibrational frequencies of the ring stretching modes of neutral and protonated species in resonance Raman spectra show shifts to both higher and lower frequencies. An analysis of the shifts of various Rama…
The authors present a review of their research work in an endeavor to interpret the behavior of zinc-rich paints (ZRP) using electrochemical impedance spectroscopy (EIS). This technique can provide much useful information about the protection mechanisms of ZRP. The tendency of some of these coatings to act like an ele…
After a brief review of the experimental data concerning phase transitions in ferroelectric thin films, a theoretical treatment based on the Landau-Devonshire expansion is presented. A surface is characterised by a length δ, the negative of the logarithmic derivative of the order parameter at the surface. For negative…