Effects of the addition of mango residue on solution combustion synthesis of iron oxides

Journal of Thermal Analysis and Calorimetry - The effects of the addition of mango residue on the combustion of iron nitrate–urea mixtures are presented herein. The process was performed...     

L2(R) Solutions of Dilation Equations and Fourier-Like Transforms

We state a novel construction of theFourier transform on L²(R) based on translation and dilation properties which makes use of the multiresolution analysis structure commonly used in the design of wavelets. We examine the conditions imposed by variants of these translation and dilation properties. This allows other characterizations of the Fourier transform to be given, and operators which have similar properties are classified. This is achieved by examining the solution space of various dilation equations, in particular we show that the L²(R) solutions of f (x) = f (2x) + f (2x - 1) are in direct correspondence with L²(-[1, 2)).     

The application of reporter gene assays for the detection of endocrine disruptors in sport supplements

The increasing availability and use of sports supplements is of concern as highlighted by a number of studies reporting endocrine disruptor contamination in such products. The health food supplement market, including sport supplements, is growing across the Developed World. Therefore, the need to ensure the quality and safety of sport supplements for the consumer is essential. The development and validation of two reporter gene assays coupled with solid phase sample preparation enabling the detection of estrogenic and androgenic constituents in sport supplements is reported. Both assays were shown to be of high sensitivity with the estrogen and androgen reporter gene assays having an EC(50) of 0.01 ng mL(-1) and 0.16 ng mL(-1) respectively. The developed assays were applied in a survey of 63 sport supplements samples obtained across the Island of Ireland with an additional seven reference samples previously investigated using LC-MS/MS. Androgen and estrogen bio-activity was found in 71% of the investigated samples. Bio-activity profiling was further broken down into agonists, partial agonists and antagonists. Supplements (13) with the strongest estrogenic bio-activity were chosen for further investigation. LC-MS/MS analysis of these samples determined the presence of phytoestrogens in seven of them. Supplements (38) with androgen bio-activity were also selected for further investigation. Androgen agonist bio-activity was detected in 12 supplements, antagonistic bio-activity was detected in 16 and partial antagonistic bio-activity was detected in 10. A further group of supplements (7) did not present androgenic bio-activity when tested alone but enhanced the androgenic agonist bio-activity of dihydrotestosterone when combined. The developed assays offer advantages in detection of known, unknown and low-level mixtures of endocrine disruptors over existing analytical screening techniques. For the detection and identification of constituent hormonally active compounds the combination of biological and physio-chemical techniques is optimal.     

Chemoenzymatic synthesis of a mixed phosphine-phosphine oxide catalyst and its application to asymmetric allylation of aldehydes and hydrogenation of alkenes

The chemoenzymatic synthesis of a Lewis basic phosphine-phosphine oxide organocatalyst from a cis-dihydrodiol metabolite of bromobenzene proceeds via a palladium-catalysed carbon-phosphorus bond coupling and a novel room temperature Arbuzov [2,3]-sigmatropic rearrangement of an allylic diphenylphosphinite. Allylation of aromatic aldehydes were catalysed by the Lewis basic organocatalyst giving homoallylic alcohols in up to 57% ee. This compound also functioned as a ligand for rhodium-catalysed asymmetric hydrogenation of acetamidoacrylate giving reduction products with ee values of up to 84%.     

Impact on school assessment where use of graphics calculators is mandatory in a related public examination

This paper reports an inquiry into assessment items classed as 'extended pieces of work' in Applicable Mathematics, in Western Australia. The principal purpose was to identify opportunities for graphics calculator use in 'extended pieces' implemented in schools. Ownership of the technology is widespread because it is mandated for the Applicable Mathematics tertiary entrance examination, which students sit at the end of the Year 12 course. Twenty-one of the twenty-eight pieces that were collected allowed for calculator use and, frequently, choosing to use the technology would have advantaged students, for instance, in supporting conjecture. Practical applications that would not be feasible to solve without the technology were included. Regression analysis and the random number generator were utilized. Overall, availability of the technology has widened the scope of approaches in 'extended pieces of work' in potentially valuable ways. Issues are how conjectures were elicited and calls for 'black box' use of the calculator.     

Separating forces in blade coating of viscous and viscoelastic liquids

Coating of viscous and viscoelastic liquids is examined both theoretically and experimentally. A single simple geometry, a blade over a rotating roll, is considered. A perturbation solution to the Navier-Stokes equations yields a lubrication theory with first order corrections for curvature and inertia. A numerical solutions by the Finite Element Method (FEM) is compared to the analytical solutions. For Newtonian fluids, agreement between these mathematical models, and data on blade loading, is quite good.The effect of a non-Newtonian viscosity is explored by adopting a purely viscous power law model. The zeroth-order (lubrication) equations are solved by the method of Steidler and Horowitz, and predictions for coating thickness and blade loading agree quite well with those obtained from a FEM solution of the full equations of motion for a power law fluid. Data on blade loading, obtained using a strongly elastic polymer solution, are compared to these mathematical models, and discrepancies are noted.     

Annealing effect on semi-crystalline materials in creep behavior

Three glass reinforced polymers of Nylon 66, PET and HT-Nylon with glass transitions of 58, 72, and 132°C are selected for checking the necessity of high temperature annealing and degree of its impact on creep strains. The improvement after annealing depends on the polymer type of whether it is fast or slow crystallizing at molding process and whether it has hydrogen bonded sheets. The physical property changes observed of these materials before and after annealing support the explanation of crystal reorganization through crystallization, free volume reduction through densification and crystal perfection through better chain packing. The prediction of long-term creep strains up to 10 years using time-temperature superposition technique has been the practice for last 13 years in our laboratory. The accuracy of the prediction are shown in confidence level of about 90%.This revised version was published online in November 2005 with corrections to the Cover Date.     

Steric and stereoelectronic effects in the synthesis and photoisomerization of a dinitrone of 2,2,4,4-tetramethylcyclobutanedione

Peroxyacid oxidation of diimine (1) yielded only the $\text{trans}$ isomer of dinitrone (2) which upon photoisomerization gave dioxaziridines (3a) and (3b) and amide (4) as the only isolable isomers; an X-ray crystallographic investigation of (1) shows a considerable geometry distortion.     

Stress-induced diffusion of macromolecules

A framework for analysis of stress-induced diffusion is presented. Diffusion of macromolecules is considered to be driven by gradients of entropic potential arising from distortion of the molecular conformation by deformation, as well as by gradients of concentration of individual molecular weight species. Resulting concentration profiles in circular capillary flow have been calculated for a system containing a single macromolecular species. Significant variations in concentration with capillary radius are predicted at full development. Estimates of the dynamics of development of these profiles indicate that the length to diameter ratios needed to see a measurable effect are proportional to the Peclet number, which may be quite large for macromolecular fluids depending on the geometry and flow velocity of the system. This effect may have implications in the rheology, chromatography, and technological uses of macromolecular fluids.     

Surface-roughness wakefield measurements at brookhaven accelerator test facility

An experiment has been carried out at the Brookhaven Accelerator Test Facility to investigate the effect of a surface-roughness wakefield in narrow beam tubes with artificially created bumps. The measurements show that the synchronous modes decay significantly due to the randomization of the roughness pattern. It is pointed out that this decay mechanism has not been investigated in the previous experiment at DESY and the investigators' conclusion does not apply for surface-roughness wakefields in real surfaces.