Role of diatoms in copepod production:good, harmless or toxic?
4 pages, 2 figures
Materials Literature
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Microstructure of novel superhard nanocrystalline-amorphous composites as analyzed by high resolution transmission electron microscopy
The recently developed, novel superhard nanocrystalline composites nc-TiN/a-Si3N4 have been investigated by means of high resolution transmission electron microscopy. The microstructure consisting of nanocrystalline TiN imbedded within a⩽1 nm thin amorphous Si3N4, the relative amount of both phases, and the TiN-crysta…
Direct synthesis of functionalized mesoporous silica by non-ionic alkylpolyethyleneoxide surfactant assembly
The co-condensation of tetraethoxysilane (TEOS) and organotrialkoxysilane [(RO)3SiR′] assembled in the presence of structure-directing non-ionic polyethyleneoxide surfactant micelles provides a convenient neutral pH synthesis methodology for the one-step preparation of organically functionalized mesostructured materia…
Structure and Morphology of Helicene Fibers
Nonracemic helicene 1 when cooled from the melt organizes itself into macroscopic liquid crystalline fibers. Transmission electron microscopic analysis shows that the fibers are comprised of lamellae 50−200 nm wide, each only ca. 10 nm high. Analyses by X-ray and electron diffraction demonstrate that the molecules are…
Rare earth stabilization of mesoporous alumina molecular sieves assembled through an N○I○ pathway
The incorporation of 1.0–5.0 mol% Ce3+ or La3+ ions in MSU-X alumina molecular sieves, prepared through an N○I○ assembly pathway, dramatically improves their thermal stability without altering the mesopore size or the wormhole channel motif.
Construction of One‐Dimensional Multicomponent Molecular Arrays: Control of Electronic and Molecular Motions
Transition metals are powerful three-dimensional templates, which can gather various functionalized ligands and orient them in a precise fashion so that complex multicomponent molecular systems can be obtained without constructing covalently-assembled edifices. The compounds thus prepared exhibit precise chemical or p…
White-noise modulation of high-frequency high-intensity discharge lamp ballasts
In this paper, a new method is proposed to avoid acoustic-resonance-related instabilities in metal halide lamps when operated with a high-frequency electronic ballast. Angle modulation of the inverter switching pattern has been used as a vehicle to randomize lamp driving frequency and to limit lamp power spectrum belo…
CO2-Catalyzed One-Electron Oxidations by Peroxynitrite: Properties of the Reactive Intermediate
In neutral bicarbonate-containing solutions, the predominant pathway for peroxynitrite decomposition was CO 2 -catalyzed formation of nitrate ion; that is, CO 2 was regenerated in the process. When nitrite ion was present, HCO 3 - also formed during ONO 2 - decomposition. The data could be reproduced by a kinetic mode…
Precious metal polymers: platinum or gold atoms in the backbone
The synthesis and characterisation of oligomers and polymers containing gold or platinum atoms in the backbone are reported. The polymers range in structure from the conjugated, rigid-rod type containing linear gold(I) centres to hyperbranched or dendrimeric materials containing octahedral platinum(IV) centres.
Formation Process of Ultrathin Multilayer Films of Molybdenum Oxide by Alternate Adsorption of Octamolybdate and Linear Polycations
Multilayer films of molybdenum oxide were prepared by means of alternate adsorption of ammonium octamolybdate ((NH 4 ) 4 [Mo 8 O 26 ]) and poly(allylamine hydrochloride) (PAH). The films were reproducibly grown at each adsorption cycle, as monitored by a quartz crystal microbalance. Adsorption of PAH on the surface of…
Functional cascade molecules
Cascade molecules/dendrimers are highly branched, regularly built molecules that have now been known for two decades. While efforts in the early stage of their investigation were directed towards the development of higher generation structures and new dendritic architectures, the design of functional dendrimers is mor…
Synthesis of mesoporous silica spheres under quiescent aqueous acidic conditions
A gyroid-to-sphere shape transition has been unveiled in the growth of mesoporous silica morphologies that are synthesized under quiescent acidic aqueous conditions. It can be induced by a decrease of the acidity for a surfactant-based gyroid preparation. As the acidity is gradually lowered from the gyroid domain, the…
Outstanding effect of SO2 addition on the rate of carbon oxidation with a Pt catalyst
Addition of trace SO2 (ca. 8 ppm) to a reactant gas containing NO substantially enhanced the oxidation rate of carbon black mixed with a Pt/SiO2 catalyst, which is attributed to SO3 (or H2SO4) catalyzing the oxidation of carbon by NO2.
Wavelength Dispersions of the Faraday Effect in Chalcogenide Glasses
Chalcogenide glasses of As20S80, Ge20As20S60, As40S60 and As40S57Se3 were prepared. The wavelength dispersions of the Faraday effect for these glasses were examined. The Verdet constants of the glasses decreased at wavelengths longer than the absorption edge of the glasses. The values of the Verdet constants of the gl…
Analysis of high strain hysteresis loss of nonlinear rubbery polymer
Abstract With the use of the Boltzmann superposition principle, a statistical theory of rubber elasticity, and phenomenological theory, the hysteresis loss at high strain (greater than 100%) of nonlinear viscoelastic materials has been quantified in terms of material parameters. The theory incorporates both experiment…
Corrosion Inhibition of Mild Steel by Schiff Base Compounds in Various Aqueous Solutions (Part 2)
The effects of Schiff base-metallocomplexes on the corrosion of mild steel were investigated by corrosion weight loss measurements, electrochemical measurements and surface analyses in various aqueous solutions such as hydrochloric acid solution and pseudo cooling water. The maximum value of inhibition efficiency on t…
Polymerization of 1-methyl-2,5-bis[1-(4-phenylurazolyl)] pyrrole dianion with alkyldihalides
1-Methyl-2,5-bis[1-(4-phenylurazolyl)] pyrrole was prepared from the reaction of 4-phenyl-1,2,4-triazoline-3,5-dione with N-methylpyrrole in methylene chloride solution. This compound was converted to its potassium dianion salt upon reaction with potassium hydroxide in absolute ethanol. The reaction of this dianion sa…
Modified Young's Modulus of Microcrystalline Cellulose Tablets and the Directed Continuum Percolation Model
The purpose of this investigation was to analyze the modified Young's modulus of microcrystalline cellulose tablets at comparatively low relative densities, based on concepts of percolation theory. Tablets were prepared and tested using a Zwick 1478 universal testing instrument. For statistical evaluation a new method…
Efficient and Mild Oxidative Decarboxylation of Aryl-substituted Carboxylic Acids by Iron and Manganese Porphyrin Periodate Systems
The oxidative decarboxylation of α-aryl carboxylic acids to the corresponding carbonyl derivatives was observed in catalytic systems containing tetrabutylammonium periodate and metallotetraphenylporphyrins (metal=FeIII or MnIII) at room temperature.
Loss and current distribution in foil windings of transformers
Detailed loss and current distributions in the foil-wound low-voltage winding of a 6 MVA transformer using a finite-element analysis package are presented. The foil-winding eddy loss is estimated and its variation with clearance to yoke is examined. Plots of foil current and eddy-current density and loss-intensity dis…