Materials Literature
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Novel guanidine bases supported on silicas and Micelle Templated Silicas (MTS) have been prepared, and investigated in the base catalysed epoxidation of electron deficient alkenes with excellent conversions and selectivities both with respect to the alkene and the primary oxidant. They are also efficient catalysts for…
Poly-DL-lactide (PLA) and poly-DL-lactide-poly(ethylene glycol) (PELA) were produced by bulk ring-opening polymerization using stannous chloride as initiator. PLA, PELA microspheres, and PELA microspheres containing the outer membrane protein (OMP) of Leptospira interrogans with the size of 1.5–2 μm were prepared by a…
Tesselation of new supramolecular motifs of the tetra(4-carboxyphenyl)porphyrin building blocks by metal ion templates has been demonstrated in crystals, characterizing the square-planar [Na+·(–COOH)4·X− ] and the tetrahedral [Zn2+·(–COOH)2·(–COO −)2] molecular recognition elements for effective multiporphyrin assembl…
The heat capacity, C p , of monocrystalline 4H‐SiC has been studied in the interval 285–770 K using differential scanning calorimetry. For comparison monocrystalline and powdered 6H‐SiC have also been measured. A suitable analytical expression is proposed for interpretation of the experimental results, which is applic…
A grafted material based on chitosan and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) has been successfully prepared in homogenous solution using potassium persulfate as a redox initiator. The grafted copolymer was precipitated during the reaction polymerization. The effects of the reaction temperature and chitosa…
The aim of this work was to point out the current performance of metallized polypropylene film capacitors. Many tests have demonstrated that the contact between the sprayed terminations and the metallized electrodes is one of the most critical points for capacitors manufactured with this technology, generally when the…
The free-floating fibroblast-populated collagen lattice (FPCL) model introduced by Bell contains 0.5 x 10(5) cell/ml and here is defined as a moderate-density FPCL (MD-FPCL). One modification of the model is to increase the cell density by a factor of 10, where 5 x 10(5) cells/ml defines a high-density FPCL (HD-FPCL).…
The localized corrosion behavior of Al 2024 was investigated by using a fluorescent dye in combination with conventional fluorescence microscopy and near‐field scanning optical microscopy. The fluorescent rings that mark the first steps of corrosion attack were associated with topographic features. The topographic rin…
Determining whether the first step of photooxygenation is Type I or Type II is a necessary prerequisite in order to establish the mechanism of photodynamic action. But this distinction is not sufficient, because other processes, both consecutive and competitive, commonly participate in the overall mechanism. Thus, in…
The europium(II) sites in Sr4Al 14O25 ∶ Eu phosphor with blue emission were examined by means of high frequency (90 and 180 GHz) EPR spectroscopy. The ions occupy two low symmetry sites in the Sr4Al 14O25 lattice with |D| = 0.100 and 0.0907 cm−1 respectively; the ratio |E/D | is estimated to be 1/3 regardless of the s…
The reaction of suitable organic groups in combination with well defined inorganic silsequioxane cores leads to covalently bound organic–inorganic hybrid materials, which exhibit nematic and smectic C phase behaiour close to room temperature.
Using a triangular ice sample, the characteristics of the DC arc appearing on ice surfaces was investigated. Based on the results obtained, a model for predicting the 50% flashover voltage of ice-covered insulators energised with DC was presented. The model takes into account the ice surface conductivity, voltage pola…
Fabric weave is a fabric-structure factor that can be represented merely graphically or as the two-dimensional matrix of the digits 1 and 0. Its estimation is very complicated if the results of experiments are generalised. Hence often only the variable properties of fabrics for specified weaves are explained, avoiding…
The last two decades have witnessed major discoveries in the field of bacterial polyesters, which makes it all the more promising as a potential biodegradable and biocompatible material. Based on the knowledge obtained, it is now possible to formulate methods to design and synthesize a particular type of bacterial pol…
Single-fibre surface-enhanced Raman sensors were prepared by depositing rough metal films at the tips of optical fibres. Different deposition techniques such as slow evaporation of metal island films and vacuum deposition of metal films over nanoparticles or on pre-roughened surfaces were applied and compared. The sup…
The relative emission yield and lifetime have been obtained as functions of concentration for both and transitions in phosphors. The concentration quenching of the transition was analyzed by intercenter energy migration on the basis of dipole‐dipole interaction. The decay behavior of transition, for which well‐known c…
The new decameric [Mo10S10O10(OH)10(H2 O)5] oxo–thio ring was prepared by self-condensation of [Mo2S2O2]2+ upon addition of hydroxide ion; crystals were obtained in dimethylformamide in the presence of tetrabutylammonium iodide; X-Ray diffraction analysis reveals a 10-membered ring-shaped cluster; the cyclic architect…
OBJECTIVE AND IMPORTANCE: To demonstrate the usefulness of positron emission tomography-magnetic resonance imaging (MRI) coregistration for differentiation of radiation necrosis and recurrent tumor in stereotactic planning. CLINICAL PRESENTATION: T1-weighted MRI scans of a 43-year-old woman revealed a contrast-enhanci…
The reactive compatibilization of immiscible polymers such as high-density polyethylene (HDPE) and poly(ethylene terephthalate) (PET) by interfacial grafting of maleic anhydride (MA) without initiator in the molten state was investigated in this study. Grafting reaction of MA onto HDPE was carried out in a Rheocord HA…
Graft copolymerization of acrylonitrile (AN) onto defatted pineapple leaf fiber (PALF) was studied using a CuSO4 and KIO4 combination as an initiator in an aqueous medium in the temperature range 30–500C. The effects of the concentration of potassium periodate, CuSO4, and monomer on the graft yield were investigated.…