Measurement of direct neutron capture by neutron-rich sulfur isotopes

Thermal neutron capture cross sections for $^{34}$S(n,$\gamma$)$^{35}$S and $^{36}$S(n,$\gamma$)$^{37}$S have been measured and spectroscopic factors of the final states have been extracted. The calculated direct-capture cross sections reproduce the experimental data.Comment: 4 pages (uses espcrc1.sty), 1 postscript figure (uses psfig), accepted for publication in Nucl. Phys. A (Suppl.), uuencoded tex-files and postscript-files available at ftp://is1.kph.tuwien.ac.at/pub/ohu/Stherm.u

Direct neutron capture cross sections of 62Ni in the s-process energy range

Direct neutron capture on 62Ni is calculated in the DWBA and the cross sections in the energy range relevant for s-process nucleosynthesis are given. It is confirmed that the thermal value of the capture cross section contains a subthreshold resonance contribution. Contrary to previous investigations it is found that the capture at higher energies is dominated by p-waves, thus leading to a considerably increased cross section at s-process energies and a modified energy dependence.Comment: 10 pages, 1 figure, corrected typos in Eq. 6 and subsequent paragrap

Fine‐scale measurement of diffusivity in a microbial mat with nuclear magnetic resonance imaging

Noninvasive 1H‐nuclear magnetic resonance (NMR) imaging was used to investigate the diffusive properties of microbial mats in two dimensions. Pulsed field gradient NMR was used to acquire images of the H2O diffusion coefficient, Ds, and multiecho imaging NMR was used to obtain images of the water density in two structurally different microbial mats sampled from Solar Lake (Egypt). We found a pronounced lateral and vertical variability of both water density and water diffusion coefficient, correlated with the laminated and heterogeneous distribution of microbial cells and exopolymers within the mats. The average water density varied from 0.5 to 0.9, whereas the average water diffusion coefficient ranged from 0.4 to 0.9 relative to the values obtained in the stagnant water above the mat samples. The apparent water diffusivities estimated from NMR imaging compared well to apparent O2 diffusivities measured with a diffusivity microsensor. Analysis of measured O2 concentration profiles with a diffusion‐reaction model showed that both the magnitude of calculated rates and the depth distribution of calculated O2 consumption/production zones changed when the observed variations of diffusivity were taken into account. With NMR imaging, diffusivity can be determined at high spatial resolution, which can resolve inherent lateral and vertical heterogeneities found in most natural benthic systems

Passive remediation of acid mine drainage using cryptocrystalline magnesite: A batch experimental and geochemical modelling approach

Acid mine drainage is generated when mining activities expose sulphidic rock to water and oxygen leading to generation of sulphuric acid effluents rich in Fe, Al, SO4 and Mn with minor concentrations of Zn, Cu, Mg, Ca, Pb depending on the geology of the rock hosting the minerals. These effluents must be collected and treated before release into surface water bodies. Mining companies are in constant search for cheaper, effective and efficient mine water treatment technologies. This study assessed the potential of applying magnesite as an initial remediation step in an integrated acid mine drainage (AMD) management system. Neutralization and metal attenuation was evaluated using batch laboratory experiments and simulations using geochemical modelling. Contact of AMD with cryptocrystalline magnesite for 60 min at 1 g: 100 mℓ S/L ratio led to an increase in pH, and a significant increase in metals attenuation. Sulphate concentration was reduced to ≈1 910 mg/ℓ. PH redox equilibrium (in C language) (PHREEQC) geochemical modelling results showed that metals precipitated out of solution to form complex mineral phases of oxy-hydroxysulphates, hydroxides, gypsum and dolomite. The results of this study showed that magnesite has potential to neutralize AMD, leading to the reduction of sulphate and precipitation of metals.SP201

Stress anisotropy in polymer brushes and its effects on wetting

Polymer brushes, coatings consisting of densely grafted macromolecules, have been known to experience an intrinsic lateral compressive stress, originating from chain elasticity and excluded volume interactions. This lateral stress complicates a proper definition of the interface and, thereby, of the interfacial tension. Moreover, its effect on wettability has remained unclear. Here, we study the link between grafting-induced compressive lateral stress in polymer brushes, interfacial tension, and brush wettability using coarse-grained molecular dynamics simulations. A central result is that the liquid contact angle is independent of grafting density, which implies that the strength of the compressive stress inside brush has no influence on the wettability. Interestingly, though the interfacial tensions lack a proper definition, the difference in interfacial tension between wet and dry brushes is perfectly well-defined. We confirm explicitly from Young's law that this difference offers an accurate description of the brush wettability. It is demonstrated how these results can be explained from the fact that the compressive stress appears "symmetrically" in wet and dry brushes. We discuss our findings in the light of autophobic dewetting and point out the connection to the Shuttleworth effect for wetting on elastomers

Keeping record of the postoperative nursing care of patients

The aim of this research project was to evaluate the recordkeeping of postoperative nursing care. A total of 186 randomly selected patient records were evaluated in terms of a checklist that included the most important parameters for postoperative nursing care. All the patients underwent operations under general anaesthetic in one month in a Level 3 hospital and were transferred to general wards after the operations. The data collected was analysed by means of frequencies. One finding was that the neurological status of most patients was assessed but that little attention was paid in the patient records to emotional status and physical comfort. The respiratory and circulatory status of the patients and their fluid balance were inadequately recorded. The patients were well monitored for signs of external haemorrhage, but in most cases haemorrhage was checked only once, on return from the theatre. Although the patients’ pain experience were well-monitored, follow-up actions after the administration of pharmacological agents was poor. The surgical intervention was fully described and, generally speaking, the records were complete and legible, but the signatures and ranks of the nurses were illegible. Allergies were indicated in the most important records. The researchers recommend that a comprehensive and easily usable documentation form be used in postoperative nursing care. Such a form would serve as a checklist and could ensure to a large degree that attention is given to the most important postoperative parameters. Errors and negligence could also be reduced by this meansHealth Studie

Sexual selection, automata and ethics in George Eliot's The Mill on the Floss and Olive Schreiner's Undine and From Man to Man

This paper brings together two related areas of debate in the latter half of the nineteenth century. The first concerns how the courtship plot of the nineteenth-century novel responded to, and helped to shape, scientific ideas of sexual competition and selection. In The Mill on the Floss (1860), George Eliot strikingly prefigures Darwin's later work on sexual selection, drawing from her own extensive knowledge of the wider debates within which evolutionary theory developed. Maggie Tulliver's characterisation allows Eliot to explore the ethical complexities raised by an increasingly powerful scientific naturalism, where biology is seen to be embedded within morality in newly specific ways. The second strand of the paper examines the extension of scientific method to human mind and motivation which constituted the new psychology. It argues that there are crucial continuities of long-established ethical and religious ideas within this increasingly naturalistic view of human mind and motivation. The contention that such ideas persist and are transformed, rather than simply jettisoned, is illustrated through the example of Thomas Henry Huxley's 1874 essay on automata. Turning finally to focus on Olive Schreiner's Undine (1929) and From Man to Man (1926), the paper explores the importance of these persistent ethical and religious ideas in two novels which remained unpublished during her lifetime. It argues that they produce both difficulty and opportunity for imagining love plots within the context of increasingly assertive biological and naturalistic accounts of human beings

Comprehensive Survey of the Distribution of Colour and Phenolics of Different Red Grape Wine Vineyard Blocks from the Robertson Area in South Africa

Colour and phenolic content of red grapes are two of the most important constituents required to producea quality red wine. In the Robertson grape growing area, difficulty is sometimes experienced with colourdevelopment of grapes. This is especially linked to location and most probably greatly influenced byseason. Forty four vineyard blocks of the cultivars Pinotage, Merlot, Cabernet Sauvignon and Shiraz,were studied over 3 seasons primarily to focus on colour and phenolic content, but secondly on totalsoluble solids, titratable acidity and pH of the grapes. High performance liquid chromatography andspectrophotometric methods were used to determine various colour and phenolic parameters present atharvest. This data was used to indicate how colour and phenolic constitution of a part of the Robertsongrape growing area was distributed in relation to various factors, such as cultivar and season. GPS pointswere used to map data for the blocks visually. Results showed variable colour and phenolic content forthese grapes based on blocks and phenolic compounds investigated. Shiraz displayed a wider distributionof certain phenolic compounds over the three seasons than the other 3 cultivars. Seasonality had a greatinfluence on these results, with outlying blocks being identified