Chromophoric potential of the 4(3H)-quinazolinones: a review

The last few decades have seen significant developments in the use of heterocyclic compounds in dyestuff and pigment chemistry. The design of newer heterocyclic systems has been a major target area and has focused on economically viable synthesis, absence of effluent problems and freedom from carcinogenic and mutagenic effects. The present article reviews the chemical and patent literature on the chromophoric potential of the 4(3 H )-quinazolinone ring system, including dyes, pigments, fluorescent brightening agents, luminescent inks, electroluminescent devices, photographic couplers, colour formers and photographic fog inhibitors.     

Gauge length effect on the tensile properties of leather

Tensile properties are important basic characteristics of materials and influence their end‐use and performance. More importantly, in the case of leather due to end‐use applications such as shoe uppers, automotive and furniture upholstery, mechanical properties such as tenacity are of extreme importance. Therefore, fundamental studies on the tensile properties of leather are needed. In this study, an attempt has been made to examine the effect of gauge length (GL) on the tensile properties of shoe upper leather. Two different specimens in the form of rectangular and dumbbell shapes have been cut from parallel and perpendicular directions to the body axis of the leather and have been tested. Results showed that the maximum breaking load and the percentage extension at break decreased with the increase in GL. Rectangular specimens showed a 30% decrease in maximum breaking load and a 13% decrease in percentage extension at break, while dumbbell specimens showed reductions in the order of 28 and 6%, respectively, as the GL increased from 9.53 cm to 23.5 cm. Highly varying supramolecular architecture of the collagen matrix and the frictional slippage caused by the free ends present in the collagen fibrils, which induce a weak‐link effect similar to the one found in cotton fibers and yarns, are considered to be the probable reasons for this behavior. A limited scanning electron microscopic study has been undertaken to pictorially represent the breakage of leather at different GLs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1202–1209, 2006     

Electrochemical synthesis of calcium carbonate coatings on stainless steel substrates

Calcite CaCO₃ has been electrocrystallized on stainless steel substrates by the galvanostatic cathodic reduction of aqueous calcium bicarbonate solutions. The deposition is controlled by pH changes occurring close to the cathode due to electrogeneration of base. The deposit morphology varies from facetted rhombs observed at low (1-20 mA cm⁻²) current densities to corner-rounded particles observed at high (40 mA cm⁻²) current densities.     

Evaluation of slow crack growth parameters for silicon carbide ceramics

The difficulties in applying existing dynamic and static fatigue theories to model the slow crack growth behaviour of silicon carbide ceramics are examined critically. The assumptions that the geometric parameter,Y, in the fracture mechanics relation remains unchanged for all flaws during crack growth and that the final crack size is much larger than the initial crack size are found to be unrealistic for silicon carbide ceramics.     

Anodic oxide coatings on Ti–6Al–4V produced from electrolyte containing Ca and P – Corrosion aspects

Electrodeposited anodic oxide coatings were produced on Ti–6Al–4V substrates using aqueous electrolytes containing dissolved calcium and phosphorus. Different coatings were produced by varying the time periods. The coatings contained TiO as the major phase and contained very small quantities of calcium and phosphorus. All the coatings were less than 200 nm thick. A point defect model is obeyed by all the coatings.     

Constituents of power of an electric dipole of finite size

An electric dipole of finite size in the form of a spherical current sheet with a surface current density in the theta direction varying as sin theta is introduced. External to the spherical surface, the electromagnetic fields are of the same form as that of a point electric dipole situated at the origin and oriented in the z direction. The power and the power flux density are separated into the radiative and the reactive parts. This type of separation of power is related to the usual separation made on the basis of propagating and evanescent waves. There is a natural relationship between the radiative and the reactive parts with the far-field and the near-field effects, respectively.     

Fundamental electromagnetic Gaussian beam beyond the paraxial approximation

The fundamental electromagnetic Gaussian beam is constructed from a single component of the electric vector potential oriented normal to the propagation direction. The potential is cylindrically symmetrical about the propagation direction. The paraxial beam and the first-order nonparaxial beam are obtained. In solving the inhomogeneous paraxial wave equation governing the evolution of the nonparaxial beam, both the particular integral and the complementary function are included. A procedure for deducing the proper asymptotic state of the nonparaxial beam is summarized. The amplitude coefficients of the cylindrically symmetric complex-argument Laguerre-Gauss beams, which constitute the complementary function are determined by requiring the potential to have the proper behavior asymptotically at infinity and near the input plane. From the potential function, the electromagnetic fields are developed and the electrodynamics of the fundamental electromagnetic Gaussian beam beyond the paraxial approximation is investigated. The role of the first-order nonparaxial beam in determining the average beam characteristics is examined.     

Sustained release of a p38 inhibitor from non-inflammatory microspheres inhibits cardiac dysfunction

Cardiac dysfunction following acute myocardial infarction is a major cause of death in the world and there is a compelling need for new therapeutic strategies. In this report we demonstrate that a direct cardiac injection of drug-loaded microparticles, formulated from the polymer poly(cyclohexane-1,4-diylacetone dimethylene ketal) (PCADK), improves cardiac function following myocardial infarction. Drug-delivery vehicles have great potential to improve the treatment of cardiac dysfunction by sustaining high concentrations of therapeutics within the damaged myocardium. PCADK is unique among currently used polymers in drug delivery in that its hydrolysis generates neutral degradation products. We show here that PCADK causes minimal tissue inflammatory response, thus enabling PCADK for the treatment of inflammatory diseases, such as cardiac dysfunction. PCADK holds great promise for treating myocardial infarction and other inflammatory diseases given its neutral, biocompatible degradation products and its ability to deliver a wide range of therapeutics.     

Radiation pattern of azimuthally varying scalar Laguerre-Gauss waves

The exact full-wave generalization of the azimuthally varying scalar real-argument Laguerre-Gauss beam is obtained. The radiation intensity of the resulting azimuthally varying real-argument Laguerre-Gauss wave is determined. The main characteristics of the radiation intensity pattern are discussed. The total power P(n,m) is determined, where n is the radial mode number and m is the azimuthal mode number. By the use of 1/P(n,m), the characteristics of the quality of the paraxial beam approximation to the real-argument Laguerre-Gauss wave are investigated.