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Material Shows (material + shows)
Selected AbstractsSt Columba and the convention at Druimm Cete: peace and politics at seventh-century IonaEARLY MEDIEVAL EUROPE, Issue 3 2007James E. Fraser Attendance at the ,convention of kings' at Druimm Cete in north-east Ireland is one of the most famous episodes in the career of St Columba or Colum Cille, who died in 597. Discussion of the significance of this shadowy summit, largely informed by unreliable late evidence, has hitherto focused upon what (may have) transpired there between kings based in Ireland and Scotland. The result has been the neglect of the hagiographical dimension of the presentation of Druimm Cete in our principal source, Adomnán's Vita Sancti Columbae, composed c.700. Analysis of this material shows that Adomnán's information about the convention came from his principal source, composed some sixty years earlier. It reveals moreover that Druimm Cete assumed prominence within the Columban dossier in the 640s for what it represented, rather than because of what actually happened there. Once the hagiographical agenda of Vita Sancti Columbae and its principal source is restored to its rightful place in evaluating the text, it emerges that several of its best-known stories , including the story of Columba's ordination of a Scottish king , are much more problematic as witnesses to sixth-century history than is conventionally supposed. As scholars begin to lose their grip upon the historical Columba, however, they grow better able to grasp seventh-century political history in north-east Ireland and Gaelic Scotland. [source] Porous Silicon-Based Optical Microsensors for Volatile Organic Analytes: Effect of Surface Chemistry on Stability and SpecificityADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Anne M. Ruminski Abstract Sensing of the volatile organic compounds (VOCs) isopropyl alcohol (IPA) and heptane in air using sub-millimeter porous silicon-based sensor elements is demonstrated in the concentration range 50,800 ppm. The sensor elements are prepared as one-dimensional photonic crystals (rugate filters) by programmed electrochemical etch of p++ silicon, and analyte sensing is achieved by measurement of the wavelength shift of the photonic resonance. The sensors are studied as a function of surface chemistry: ozone oxidation, thermal oxidation, hydrosilylation (1-dodecene), electrochemical methylation, reaction with dicholorodimethylsilane and thermal carbonization with acetylene. The thermally oxidized and the dichlorodimethylsilane-modified materials show the greatest stability under atmospheric conditions. Optical microsensors are prepared by attachment of the porous Si layer to the distal end of optical fibers. The acetylated porous Si microsensor displays a greater response to heptane than to IPA, whereas the other chemical modifications display a greater response to IPA than to heptane. The thermal oxide sensor displays a strong response to water vapor, while the acetylated material shows a relatively weak response. The results suggest that a combination of optical fiber sensors with different surface chemistries can be used to classify VOC analytes. Application of the miniature sensors to the detection of VOC breakthrough in a full-scale activated carbon respirator cartridge simulator is demonstrated. [source] Pore-system characteristics of pavement seam materials of urban sitesJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 1 2006Thomas Nehls Abstract The original light-brown sandy seam filling of pavements in urban areas turns dark and changes its properties by the time due to various inputs of urban dust. Deposited Corg inputs do mostly not have natural characteristics but are man-made, e.g., diesel dust. Thus, properties of the seam material are not predictable from experiences with forest or agricultural soils. Semiperviously sealed urban areas are sites of contaminant deposition as well as groundwater recharge. For an assessment of the resulting groundwater-contamination risk in these areas, the properties of the seam material, which influences transport processes, must be known. The aim of this study was to investigate the pore-system build-up, which includes size distribution and fractal character in the seam material of urban sites. The investigated samples were taken from pavements adjacent to roads in Berlin and Warsaw. The micropore parameters (nanometer range) were characterized using water-vapor desorption isotherms, mesopore parameters (micrometer range) were estimated from mercury-intrusion porosimetry and macropore parameters (millimeter range) from water-retention curves. Particle density, dry bulk density, and particle-size distribution were measured using standard methods. Volumes of micro- and mesopores as well as particle densities and dry bulk densities correlated with Ctot contents. However, no such relation was found for macropore volumes. Compared to the original sandy seam filling, the altered seam material shows significantly higher Corg contents and higher amounts of micro- and mesopores. Therefore, the available water capacity increases by 0.05,0.11,m3,m,3, as compared to the original sandy seam filling. Compared to natural sandy soils having similar Corg contents, the seam material shows similar macropore volumes, but the volume of mesopores and micropores is a few times smaller. That is mainly because of the particulate character of the organic matter. [source] A NEW SEA SPIDER (ARTHROPODA: PYCNOGONIDA) WITH A FLAGELLIFORM TELSON FROM THE LOWER DEVONIAN HUNSRÜCK SLATE, GERMANYPALAEONTOLOGY, Issue 5 2006MARKUS POSCHMANN Abstract:, A new Lower Devonian sea spider (Arthropoda: Pycnogonida) from the Hunsrück Slate, Germany, is described as Flagellopantopus blocki gen. et sp. nov. This is only the sixth fossil pycnogonid species to be described. Its most remarkable and unique aspect is the long, flagelliform telson. Although our fossil apparently lacks chelifores (an apomorphy), the retained telson and the segmented trunk end behind the last pair of legs resolve F. blocki to a fairly basal position in the pycnogonid stem lineage. It probably lies between Palaeoisopus problematicus Broili, which has a lanceolate telson and the most trunk segments of any sea spider, and all other Silurian,Recent Pycnogonida. Our new material shows that at least two fossil pycnogonids retained a telson, albeit with very different morphologies, and further supports the idea that a greater diversity of body plans existed among the Palaeozoic pycnogonid taxa. [source] A TERRESTRIAL STEREOSPONDYL FROM THE LOWER TRIASSIC OF SOUTH AFRICA: THE POSTCRANIAL SKELETON OF LYDEKKERINA HUXLEYI (AMPHIBIA: TEMNOSPONDYLI)PALAEONTOLOGY, Issue 2 2005K. PAWLEY Abstract:, Description of the postcranial skeleton of the basal stereospondyl amphibian Lydekkerina huxleyi from new material shows it to be heavily ossified with large processes for muscle attachment and well-developed articulation surfaces. The structure of the postcranial skeleton implies a substantial capability for terrestrial locomotion, rather than a primarily aquatic existence as has been suggested for most other stereospondyls. The postcranial skeleton is most similar to that of Uranocentrodon and the Archegosauroidea, and is unlike that of the poorly ossified, more derived stereospondyls and Dvinosauria. The postcranial skeleton does not display any of the particular apomorphies of the fully ossified Permian terrestrial temnospondyls. Cladistic analysis using the postcranial data obtained in this study indicates that within the Stereospondyli Lydekkerina huxleyi is neither a member of the Rhinesuchidae nor the Mastodonsauroidea, rather the Lydekkerinidae are a separate taxon. [source] EXPERIMENTAL VACUUM SPRAY DRYING OF PROBIOTIC FOODS INCLUDED WITH LACTIC ACID BACTERIAJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2009YUTAKA KITAMURA ABSTRACT This research aims to develop a vacuum spray dryer (VSD) that performs spray drying in a vacuumed drying tower at a lower temperature than the conventional spray drying. The VSD operational drying temperatures for the probiotic foods containing lactic acid bacteria were determined by the relationships between the temperature and the vapor pressure, and were correlated by Clapeyron's equation. The drying of the fermented milk starter at 35C drying tower was experimentally possible; however, powder from the lactic fermenting beverage was not obtained even at 50C, which resulted from the lower glass transition temperature of the material. Compared with ATP concentration of the fermented milk starter before and after the VSD drying, the lower the drying temperature, the higher the microbial activity is retained. The ATP ratio as 30% of the raw materials shows the high feasibility of VSD for dairy processing. PRACTICAL APPLICATIONS During the spray drying of liquid or slurry food, the heat-sensitive functional ingredients such as vitamin, enzyme or bacteria are usually degraded or lost because of the contact with hot air between 120 and 180C. Markets need food powder that involves a lot of functional materials and a long shelf life for the expansion of healthy food. The experimental vacuum spray dryer (VSD) showed a potential to dry probiotic foods involving lactic acid bacteria without their inactivation. Although the lactic acid bacteria contained in the powder at 35C,VSD was 30% of the raw material, it is more economical than using the liquid type fermented milk starter. With some mechanical or operational modifications for the high moisture content and low recovery ratio of the powder, VSD is applicable for dairy processing factories. [source] | ||||||||||