On the nature of elementary reactions from methane to hydrogen over transition metals

Elementary reactions that are relevant to catalytic hydrogen production have been evaluated over a wide range of transition metals. The UBI-QEP formalism was used to estimate heats of chemisorption and activation energies. The reactions were evaluated on a clean surface with the primary purpose of illustrating relative differences of intrinsic properties. The results were supportive of what is typically observed experimentally, in particular with respect to the relative difference between classical combustion catalysts (Pt, Pd) and state-of-art reforming catalysts (Ni, Rh). The likely scrambling of CH_x species was also predicted which is in accordance with isotopic tracer studies in the literature.     

Optical Attenuation Characterization of Water Contaminated Lubricating Grease

Water-contaminated grease samples are investigated with attenuation spectra in the visible and near-infrared (NIR) regions in this article. The purpose of this investigation was to identify a model with optical attenuation spectra such that the water content of grease samples could be characterized with a simple measurement setup using common methodology from the field of instrumental chemistry. The ratio between two chosen wavelengths of light appears to approximate the water content of grease samples with an acceptable coefficient of determination using a methodology to show what can potentially be done to develop condition monitoring tools. To illustrate the outlined method, a prestudy of grease aging and oxidation levels is also investigated to show that other variables do not significantly change the measurement.     

Aliphatic polycarbonate resins for radiation curable powder coatings

Thermosetting resins based on semi-crystalline poly(dimethyl trimethylene carbonate) (PDTC) were synthesised and characterised. Polymers with linear and branched architectures were synthesised through cationic ring opening polymerisation (CROP) of dimethyl trimethylene carbonate (DTC) using a series of polyols as initiators and fumaric acid as catalyst. The best powders were stable during storage at 45 °C for one week and could subsequently form films at temperatures between 100 and 115 °C. Functionalisation of the resins with methacrylic anhydride enabled curing by UV-initiated radical polymerisation. Rheology measurements showed that the architecture had a significant effect on the melt viscosity, which shows that the rheological properties can be tuned for use as low temperature curing powder coatings.     

Improved tools for efficient mapping of fission yeast genes: identification of microtubule nucleation modifier mod22‐1 as an allele of chromatin‐ remodelling factor gene swr1

Fission yeast genes identified in genetic screens are usually cloned by transformation of mutants with plasmid libraries. However, for some genes this can be difficult, and positional cloning approaches are required. The mutation swi5‐39 reduces recombination frequency in homozygous crosses and has been used as a tool in mapping gene position (Schmidt, 1993 ). However, strain construction in swi5‐39‐based mapping is significantly more laborious than is desirable. Here we describe a set of strains designed to make swi5‐based mapping more efficient and more powerful. The first improvement is the use of a swi5Δ strain marked with kanamycin (G418) resistance, which greatly facilitates identification of swi5 mutants. The second improvement, which follows directly from the first, is the introduction of a large number of auxotrophic markers into mapping strains, increasing the likelihood of finding close linkage between a marker and the mutation of interest. We combine these new mapping strains with a rec12Δ‐based approach for initial mapping of a mutation to an individual chromosome. Together, the two methods allow an approximate determination of map position in only a small number of crosses. We used these to determine that mod22‐1, a modifier of microtubule nucleation phenotypes, encodes a truncation allele of Swr1, a chromatin‐remodelling factor involved in nucleosomal deposition of H2A.Z histone variant Pht1. Expression microarray analysis of mod22‐1, swr1Δ and pht1Δ cells suggests that the modifier phenotype of mod22‐1 mutants may be due to small changes in expression of one or more genes involved in tubulin function. Copyright © 2009 John Wiley & Sons, Ltd.     

Localization of human BRCA1 and its loss in high-grade, non-inherited breast carcinomas

Although the link between the BRCA1 tumour-suppressor gene and hereditary breast and ovarian cancer is established, the role, if any, of BRCA1 in non-familial cancers is unclear. BRCA1 mutations are rare in sporadic cancers, but loss of BRCA1 resulting from reduced expression or incorrect subcellular localization is postulated to be important in non-familial breast and ovarian cancers. Epigenetic loss, however, has not received general acceptance due to controversy regarding the subcellular localization of BRCA1 proteins, reports of which have ranged from exclusively nuclear, to conditionally nuclear, to the ER/golgi, to cytoplasmic invaginations into the nucleus. In an attempt to resolve this issue, we have comprehensively characterized 19 anti-BRCA1 antibodies. These reagents detect a 220-kD protein localized in discrete nuclear foci in all epithelial cell lines, including those derived from breast malignancies. Immunohistochemical staining of human breast specimens also revealed BRCA1 nuclear foci in benign breast, invasive lobular cancers and low-grade ductal carcinomas. Conversely, BRCA1 expression was reduced or undetectable in the majority of high-grade, ductal carcinomas, suggesting that absence of BRCA1 may contribute to the pathogenesis of a significant percentage of sporadic breast cancers.     

Optimization-based computation of analytic interpolants of bounded complexity

This paper provides a unifying algorithm for computing any analytic interpolant of bounded complexity. Such computation can be performed by solving an optimization problem, due to a theorem by Georgiou and Lindquist. This optimization problem is numerically solvable by a continuation method. The proposed numerical algorithm is useful, among other cases, for designing a low-degree controller for a benchmark problem in robust control. The algorithm unifies previously developed algorithms for the Carathéodory extension and the Nevanlinna–Pick interpolation to one for more general interpolation problems.     

Effect of Nozzle Type and Swirl on Flow Pattern for Initial Filling Conditions in the Mould for Up‐hill Teeming

With increasingly more stringent requirements on steel quality and productivity in uphill teeming production, it is vital to attain more desirable fluid flow conditions in the filling of the mould. In this investigation, physical and mathematical modelling was carried out to study the effects of nozzle type and utilization of a swirl generator in the inlet nozzle on the flow pattern in the ingot mould during the initial filling period. Specific focus was on the effects on the resultant hump and axial velocities. Three cases were considered: 1) a straight nozzle, 2) a divergent nozzle, and 3) a divergent nozzle combined with a swirl generator. It was found that usage of the divergent nozzle, compared to the straight nozzle, resulted in a smaller hump and lower axial velocities in the bath. For the combination of divergent nozzle and swirl generator, these findings were even more pronounced, with the hump practically eliminated, and the axial velocities, as well as the turbulence at the meniscus, significantly lower. The findings of the study suggest that a divergent nozzle combined with a swirling flow generated in the nozzle could be used in the up‐hill teeming process in purpose to get calmer initial filling conditions.     

Energy savings combined with lignin extraction for production increase: case study at a eucalyptus mill in Portugal

In previous research by the authors, energy savings combined with lignin extraction as a means to debottleneck the recovery boiler were evaluated on a model mill. The study showed that this concept was a profitable alternative to recovery boiler upgrade. In the present paper the concept was taken one step further, and the potential for energy savings and possibilities for lignin extraction were evaluated at a real mill: a market pulp mill in Portugal. The energy-saving methods proved to be applicable also to the real mill and the steam-saving potential was 4.2 GJ/ADt or 33%. Lignin extraction trials with bench scale equipment showed that lignin extraction was fully viable at the studied mill. A full-scale lignin separation plant according to the LignoBoost concept, combined with energy savings, was simulated in a computer environment and compared to installation of a new recovery boiler. A new recovery boiler had an investment cost four times higher than the LignoBoost concept combined with energy savings, but the electricity production would be higher. The profitability for a production increase of 16% was calculated for both cases. Steam savings combined with LignoBoost were found to have better profitability unless the electricity price is very high.