Materials Literature
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Previously synthesized lactic/glycolic acid (PLGA) oligomers with different compositions (i.e. different ratio of lactic to glycolic acid in the oligomers) were further studied regarding their biodegradation and drug delivery application. The PLGA oligomers have fast biodegradation characteristics. They degrade to wat…
The recently proposed strategy for studying the equilibrium thermodynamics of the glass phase using a molecular liquid is reviewed and tested in details on the solvable case of the p-spin model. We derive the general phase diagram, and confirm the validity of this procedure. We point out the efficacy of a system of tw…
Abstract This paper shows for the first time that when a monomer is to be grafted onto a polymer backbone by a free radical mechanism in a twin screw extruder, the grafting process occurs mainly, if not exclusively, in the plastification (melting) zone. For this purpose, the free radical grafting of glycidyl methacryl…
Description This publication will advance the knowledge of those simple, yet complicated, devices known as anti-friction bearings, be they ball, roller, or needle. 33 peer-reviewed papers present the work of researchers from Austria, Belgium, China, France, Germany, Greece, Japan, Netherlands, Russia, Sweden, UK, and…
α-Mn2O3 (containing a minor proportion of Mn5O8) was obtained by calcination of pure MnO2 at 700°C for 2 h. It was alkalized by impregnation of the parent dioxide with potassium and barium nitrate solutions prior to the calcination. K-Mn2O3 (α-Mn2O3+KMn8O16) and Ba-Mn2O3 (α-Mn2O3) thus respectively produced were subje…
Reaction of 8,12-diethyl-2,3,7,13,17,18-hexamethylcorrole (1) with POCl3 in pyridine affords the first non-metal derivative of corrole; in this compound, 2, the phosphorus is in a pentavalent state and is different from analogous complexes of porphyrins.
In the novel double salt Ag2C2·2AgClO4·2H2O, the C22– dianion [bond length 1.217(7) Å] is encapsulated inside an octahedral Ag6 cage, and the resulting cationic [C2@Ag6] units share corners to generate metallic layers between which the perchlorate anions and aqua ligands are accommodated.
Visualization of structural details of specimens in field emission scanning electron microscopy (FE-SEM) requires optimal conductivity. This paper reports on the differences in conductive layers of Au/Pd, Pt and Cr, with a thickness of 1.5–3.0 nm, deposited by planar magnetron sputtering devices. The coating units wer…
We present complex admittance measurements on single-crystal yttria-stabilized zirconia and polycrystalline ${\mathrm{Li}}_{0.5}{\mathrm{La}}_{0.5}{\mathrm{TiO}}_{3}$ over the frequency range 5 Hz to 30 MHz and at temperatures ranging between 150 and 650 K. Electric-field relaxation in both fast ionic conductors can b…
Perovskite powders of La0.3Sr0.7CoO3–δwere prepared by the thermal decomposition of precursor complexes derived from nitrate solutions using ethylenediaminetetraacetic acid (EDTA) as a complexing agent. The calcination temperature is 920 °C. Powders thus obtained have a low carbon contamination. Dense ceramics with a…
Magnetic and structural properties of sintered NdFeB magnets with addition of various amounts of DyGa as a separate powder are studied and compared with single-powder magnets of the same nominal composition. When the magnets are annealed above 640 °C, the coercivity decreases strongly as compared to magnets annealed b…
Nanosize particles of SrFe12O19 have been synthesized by a citrate precursor technique with various Fe/Sr ratios of 12.0 to 9.0. X-ray diffraction (XRD) studies showed the formation of ultrafine, monophasic SrFe12O19 particles with comparable unit cell parameters. Magnetic clusters were observed by scanning electron m…
M. Ogawa, Annu. Rep. Prog. Chem., Sect. C: Phys. Chem., 1998, 94, 209 DOI: 10.1039/PC094209
A thermostable polysaccharide‐protein complex capable of accelerating the deterioration of mild steel was produced by a marine strain of sulfate‐reducing bacterium of the genus Desulfovibrio, and partially purified using low‐pressure chromatography. This complex induced pitting of steel in oxic aqueous solution. The i…
The cattle feedlot industry is under increased scrutiny and regulatory involvement at state and national levelswith regard to particulate matter (PM) emissions from fugitive sources. Concentrations of total suspended particulatematter (TSP) and PM less than 10 micrometers (PM10) aerodynamic equivalent diameter (AED) w…
Hysteresis is present to varying degrees in virtually all dynamic smart material systems. In many applications, it can be limited through the choice of materials and operating regimes so that linear, anhysteretic models are applicable. With the advent of new high performance materials and more strin gent performance…
Optimized geometries, vibrational frequencies, scale factors, and IR absorption intensities were calculated for the 1,2,3-triazole anion ( 1 ) at the B3LYP, LDA, BLYP, BVWN, HF, and MP2 levels of theory using the 6-31G** (BS1), 6-31++G** (BS2), cc-pVDZ (BS3) and aug-cc-pVDZ (BS4) basis sets and for 1,2,4-triazole ( 2…
Phase relations including reoxidation and decomposition reactions were investigated for samples with nominal composition LaCoO3–δ(0.00≤delta;≤0.50). LaCoO3–δwas synthesized by isothermal reduction at 673 K. Forδ=0.50 and 0.33 distinct phases occur, namely La2Co2O5 and La3Co3O8 . La2Co2O5 oxidizes via La3Co3O8 to LaCoO…
Three cardenolide glycosides, calotropin (1), frugoside (2), and 4'-O-beta-D-glucopyranosylfrugoside (3), were obtained as the cytotoxic principles of "akond mul" (roots of Calotropis gigantea L.). The cytotoxicity of these compounds against various cell lines of human and mouse origin was tested. They showed similar…
Under base catalyzed conditions, reaction of azuliporphyrin 3 with tert-butyl hydroperoxide affords the benzocarbaporphyrins 2a and 2b; a mechanism for the formation of 2b is proposed.