Materials Literature
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Singlet oxygen (1O2), a highly reactive and toxic intermediate, may play a role in photo-induced aging. We examined singlet oxygen generation from hematoporphyrin (HP) with UV-A, by monitoring the emission at 1,268 nm corresponding to 1O2 --> 3O2. Singlet oxygen was formed HP-dose-dependently in this system. We then i…
Single-crystal magnetisation and polarised neutron diffraction (PND) measurements have been made for the complex cis-[ReCl 4 (NHCMeNHPh) 2 ]. At higher temperatures the magnetic behaviour is typical of such a rhenium-(IV) complex, with three unpaired spins (µ = 3.6 µ B ), an almost isotropic g-tensor of 1.86(1) and a…
Three N,N″-bis(amide) derivatives of H 5 dtpa (diethylenetriamine-N,N,N′,N ″,N″-pentaacetic acid), H 3 L 1 = bis- (isopropylamide), H 3 L 2 = bis(tert-butylamide) and H 3 L 3 = bis(benzylamide), were synthesized. Their protonation constants were determined by potentiometric titration in 0.10 mol dm -3 KCl and by NMR p…
In-situ deposition of conducting polypyrrole thin films on an insulating substrate has been achieved by chemical polymerization of pyrrole on a modified surface. The surface modification agent was a silane compound bearing a pyrrole group; C 4 H 4 NC 3 H 6 Si(OMe) 3 which attached to the SiO 2 -Si surface via molecula…
Mechanical damage to thin, protective oxide layers arises principally in service from differential strains produced by temperature changes. For typical alumina- or chromia-forming alloys, in-plane tensile stresses are developed within the oxide layer during upward temperature transients and compressive stresses are pr…
Liquid crystalline alkane-3,4-dienoates (allenylacetates) have been synthesized. Most compounds incorporate a heterocyclic 1,3,4-thiadiazole ring or a pyrimidine ring as a constituent of the rigid core. These axial chiral allene derivatives were at first obtained as racemic mixtures. Some of them were also synthesized…
Physical theories concerning the structures and properties of chiral smectic liquid crystals abound, however, very few are of practical use in the design and subsequent synthesis of materials. The development of macroscopic theories, although very useful in the explanation of physical phenomena, are not readily transf…
This paper reports the incorporation of a nonamphiphilic blue laser dye 2,2‘- p -phenylenebis(5-phenyloxazol), abbreviated as POPOP, in Langmuir−Blodgett (LB) films mixed with stearic acid (SA) and their spectroscopic properties. The surface pressure versus area per molecule isotherms of POPOP mixed with SA at differe…
Abstract The use of ozone and hydrogen peroxide for the simultaneous oxidation of nitrogen and sulfur oxides was studied in experiments carried out in a stirred cell. It was found that in a gas mixture, containing both nitrogen and sulfur oxides, only the nitrogen oxides are oxidized by ozone. Contrary to earlier resu…
In order to test the influence of ceramic morphology and particle size on the behaviour of the ceramic/polymer/drug composite α-Al 2 O 3 /poly(l-lactic acid)/poly(methyl methacrylate)/ibuprofen (α-Al 2 O 3 /PLLA/PMMA/IB) containing the antiinflammatory drug ibuprofen, have been studied. We have used α-alumina synthesi…
A detailed study of the wavelength dependence of the formation of lenslets by photo-expansion in chalcogenide glasses is reported. Photo-expansion in chalcogenide glasses offers a one-step fabrication process to record surface structures such as gratings and microlenses. The process is purely optical and requires no f…
Classical Powder Diffraction usually assumes samples with completely random orientation distribution of the crystallites. It can be generalized to non‐random orientation distribution (texture) by introducing a texture factor which enters the expression of the integral intensity directly and serves as a weight function…
An experimental and numerical study of solidification characteristics of a droplet on a horizontal cooled wall is reported. Pure water and molten salt were utilized as the testing liquids. The droplet was cooled under a variety of conditions such as wall temperature and initial liquid temperature in a static atmospher…
Heat treatment of 60CaO·27Al 2 O 3 ·13Fe 2 O 3 glass resulted in a precipitation of antiferromagnetic dicalcium ferrite (Ca 2 Fe 2 O 5 ) and mayenite (12CaO·7Al 2 O 3 ). The effective magnetic moment of the sample decreased from 2.0 to 1.7 µ B owing to the precipitation of antiferromagnetic particles. The Mössbauer sp…
Abstract Films of bacterial poly(3‐hydroxybutyrate), obtained by crystallization from the melt at different temperatures up to 120°C, were investigated by powder X‐ray diffraction analysis and optical microscopy. With increasing crystallization temperature ( T c ) the diffraction patterns differed more and more from t…
Strong exciton coupling occurs between adjacent pairs of naphthyl chromophores in the chiral sodium and europium complexes of L 1 ; in the constitutionally isomeric complexes of L 2 , intramolecular excimer formation is observed and both sets of Eu complexes give a well defined, metal-based circularly polarised emissi…
A method for the preparation of amorphous Fe 3 O 4 powder with a particle size of ca. 25 nm is reported. Amorphous Fe 3 O 4 powder can be simply synthesized by slowly exposing amorphous Fe powder to the air. The amorphous properties of Fe 3 O 4 nanoparticles were characterized by X-ray diffraction, Mössbauer spectrosc…
Abstract Based on a comprehensive review of the literature on textile fabric porosity, air permeability, and related research on fabric geometry, a study of the relationships between air permeability measurements and fabric pore size was undertaken using liquid porosimetry. Experiments were conducted on ten woven text…
The reaction of phenoxide ion with the copper(II), nickel(II) and free-base 2-nitro-5,10,15,20-tetraphenylporphyrins, 1–3 respectively, has been investigated as a means of introducing inwards-directed functionality to the periphery of pre-existing porphyrin systems. It has been found that phenoxide ion shows highly se…
4,5-Dipentyldiiminoisoindoline 1 reacts with hexachlorodisilane (Si 2 Cl 6 ) to give the ring-contracted hydroxysilicon-α,β,γ-triazatetrabenzcorrole 4 which in solution photolyses giving the ring cleavage compounds 5 and 6; the stability of triazatetrabenzcorroles 4 and 7 with silicon and germanium as central elements…