Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXT2-(4'-Nitrenophenyl)-4,4,5,5-tetramethyl-4,5-dihydro- 1H-imidazole-3-oxide-1-oxyl: Photogeneration of a Quartet State Organic Molecule with Both Localized and Delocalized SpinsPaul M. Lahti, Burak Esat, and Richard WaltonView Author Information Department of Chemistry,…
Localized axisymmetric inhomogeneous states with a continuous distribution of the director field can exist in nematics. Such structures are compressed into dense filaments under the influence of a magnetic or electric field. It is hypothesized that the given states can be achieved in filamentary nematic textures. This…
In the flexoelectrooptic (FEO) effect an electric field E, applied perpendicular to the helix axis of a short-pitch cholesteric makes the director turn an angle φ(E) and thereby the optic axis by the same amount. The director rotation is coupled to a periodic splay-bend director pattern (inverse flexoelectric effect)…
It is a well-known fact that the spectra of oxygen-rich circumstellar dust envelopes around evolved stars show great diversity, especially in the 10 μm silicate band profiles, but also in the longer infrared wavelength range covered by ISO. This supports earlier conclusions that the concept of a universal cosmic silic…
Temperature dependencies of magnetic properties were measured in barium-ferrite thin films with grains having in-plane aligned as well as randomly oriented easy axes. The temperature dependence of H/sub c/ was shown to be similar to that of the effective anisotropy field, which is determined by the crystalline and sha…
Real time dosimetry was used to analyze nuclear medicine technologist dose from performing positron emission tomography clinical imaging procedures. The purpose was to identify which tasks in the procedure were the greatest contributors to dose. Results identified the patient positioning task as the single largest sou…
The murein wall in Gram-negative bacteria is so thin that the mechanism of growth is necessarily complicated. From analytical data of murein components, Höltje suggested a model for the growth mechanism that would lead to safe wall enlargement. The model depended on the formation of trimers of peptidoglycan disacchari…
A theory for approximately steady thermal degradation of solids is developed from a superset of nonlinear integral-differential equations. The theory extends previous work, using a degradation model that is more consistent than previously published models and fully accounts for surface radiation losses. The thermal de…
Hydrocarbon radicals, methyl and methylene, are generated through hot nozzle sources and dosed onto Cu(111) at 300 K. High resolution electron energy loss spectroscopic measurements show that for the CH2 exposed sample, the radical not only can be chemisorbed on the surface but also can diffuse and react to form compl…
The structural changes induced by ${}^{3}\mathrm{He}$ in Pd and Pd-based alloys ${\mathrm{Pd}}_{90}{\mathrm{Rh}}_{10}$ and ${\mathrm{Pd}}_{90}{\mathrm{Pt}}_{10}$ during tritium storage have been studied by x-ray diffraction, neutron diffraction, and x-ray absorption. During the first 3 months of aging, the large cell…
A series of water-soluble viologen-linked zinc porphyrins with different methylene chain lengths (n = 3−6) between porphyrin and viologen, ZnP ( C n V ) 4 , were synthesized and characterized. The intra- molecular electron transfer rate constants from the porphyrin moiety of ZnP (C n V ) 4 to viologen were measured by…
Navicula krasskei Hustedt has been considered to belong to the group of diatoms including Fallacia festiva (Krasske) Mann & Stickle and F. monoculata (Hustedt) Mann & Stickle. Examination of N. krasskei in the SEM revealed that this taxon does not, in fact, share features with either Fallacia or Navicula sensu stricto…
Article Isothermal and Nonisothermal Melt Crystallization Kinetic Behavior of Poly(Aryl Ether Biphenyl Ether Ketone Ketone): PEDEKK was published on May 1, 1998 in the journal Journal of Polymer Engineering (volume 18, issue 4).
To better understand how an enzyme controls cofactor chemistry, we have changed a tryptophan synthase residue that interacts with the pyridine nitrogen of the pyridoxal phosphate cofactor from a neutral Ser (beta-Ser377) to a negatively charged Asp or Glu. The spectroscopic properties of the mutant enzymes are altered…
Abstract A mixed-valence cobalt(II, III) complex, [Co6L2(CH3COO)2(CH3O)6L′]·2CH3OH(H3L=2,6-bis(saliclylideneaminomethyl)-4-methylphenol and H2L′=salicylazine), has been isolated and characterized by X-ray crystallography, which reveals a unique hexanuclear structure consisting of two defective cubane-cores.
In this work, we have used a new technique to characterize optically a periodically modulated metal–dielectric interface involving the measurement of the azimuthal-angle-dependent specular reflectivity. This method presents advantages over the conventional polar angle scan experiment since it requires no moving signal…
We present measurements of the internal friction (Q−1) and speed of sound variation (δv/v0) of amorphous boron (a-B) and amorphous B9C (a-B9C). The elastic properties of these materials, which can only be produced as thin films, are consistent with those of other amorphous solids measured to date and exhibit good agre…
The kinetics and mechanisms of metal catalysed filamentous carbon formation and gasification are reviewed. In the process of filament growth metal crystallites are removed from the surface, so that cycles of coking/decoking can severely damage reactor surfaces and supported metal catalysts. These effects are exemplifi…
Mass reduction of plastic bottles containing non-carbonated liquids calls for advanced design approaches. Weight reduction of bottles consequently influences the mechanical performance of the bottle. This performance involves top load, vacuum and impact resistance. The present paper studies the lateral deformation of…
Detailed experimental results of a systematic investigation of the dynamics of the in-plane smectic layer reorientation in SmC* ferroelectric liquid crystals on application of different types of asymmetric electric fields are reported. The reversible reorientation of smectic layers is characterized as a function of fi…