Anisotropy in the Spatial Distribution of Roller-Measured Soil Stiffness

The geostatistical analysis of roller-measured soil properties (from continuous compaction control and intelligent compaction) is required for advanced quality control/quality assurance of earthwork and asphalt compaction. This paper explores the existence of anisotropy in the spatial distribution of roller-measured soil stiffness and the effect of anisotropy on kriging. Field testing was conducted to collect roller measurement value (MV) data over typical roadway embankment evaluation areas and on a large square area to enable a robust investigation of anisotropy. The semivariogram analysis of the field data clearly indicates that range anisotropy exists. The spatial distributions of roller MV data are different in the longitudinal x-direction than in the transverse y-direction. Magnitudes of range anisotropy (x-range/y-range) varied from 2.4 to over 5. The observed range anisotropy is not due to the roller measurement system; rather, it is likely due to the directional nature of earthwork construction activities and to alignment geometry. The influence of anisotropy on kriging was found to be significant when considering the use of kriged data in earthwork specifications. The error introduced by not accounting for anisotropy in kriging varied from 5 to 17% when considering pass to pass or layer to layer map analysis. The anisotropy in the spatial distribution of roller MV data should be factored into kriging and other geostatistical analyses. For typical earthwork area geometries, the roller mapping procedure requires a slight modification to determine the y-range and anisotropy ratio.     

Detection of Escherichia coli and identification of enterotoxigenic strains by primer-directed enzymatic amplification of specific DNA sequences

The polymerase chain reaction (PCR) was used to amplify DNA sequences from the malB operon of Escherichia coli. All E. coli strains tested yielded the specific DNA fragment. No amplification products were obtained with other Enterobacteriaceae. E. coli strains which produce enterotoxins were identified with additional primer pairs specific for the genes coding for the heat-labile toxin type I (LTI) and the heat-stable toxin type I (STI). Amplification products were identified by DNA-DNA hybridization. Alternatively, restriction endonuclease analysis was used for identification and to distinguish between different alleles of the enterotoxin genes. The detection limit was 10 bacteria. The PCR systems were validated by testing 27 E. coli of known enterotoxigenic properties. The PCR results were consistent with factual toxin production as determined by immunoassays. In addition, 58 E. coli strains isolated from soft cheese and mayonnaise were analyzed by PCR. One strain from a cheese sample was found to have the genetic information for STI production. This strain produced STI as determined by enzyme-linked immunosorbent assay.     

Processing of Nickel‐Base Superalloys for Turbine Engine Disc Applications

Nickel‐base superalloys used for critical rotating disc components have evolved into advanced, high performance, application‐specific materials. The designs of modern turbine machinery applications have dictated a shift in material performance requirements from an emphasis solely on burst and creep strength to the addition of minimized fatigue crack growth rates and component residual stresses. Increased component performance has often resulted in material and process changes that are accompanied by subsequent manufacturing difficulties. For example, increased alloy content has pushed the primary processing route from ingot metallurgy toward powder metallurgy methods. The processing routes required in the manufacture of these materials are equally as complex as the alloys themselves and have a strong influence on the resultant properties of turbine engine discs. Challenges still lie ahead for material and process engineers working on these materials. Both turbine engine design changes and market pressures will mandate novel materials and processes that allow for cost effective solutions for the harsh environment applications these nickel‐based superalloys have evolved to fill.     

Adsorption of arsenic on polyaluminum granulate

The kinetics and efficiencies of arsenite and arsenate removal from water were evaluated using polyaluminum granulates (PAG) with high content of aluminum nanoclusters. PAG was characterized to be meso- and macroporous, with a specific surface area of 35 ± 1 m(2) g(-1). Adsorption experiments were conducted at pH 7.5 in deionized water and synthetic water with composition of As-contaminated groundwater in the Pannonian Basin. As(III) and As(V) sorption was best described by the Freundlich and Langmuir isotherm, respectively, with a maximum As(V) uptake capacity of ~200 μmol g(-1) in synthetic water. While As(III) removal reached equilibrium within 40 h, As(V) was removed almost entirely within 20 h. Micro X-ray fluorescence and electron microscopy revealed that As(III) was distributed uniformly within the grain, whereas As(V) diffused up to 81 μm into PAG. The results imply that As(V) is adsorbed 3 times faster while being transported 10(5) times slower than As(III) in Al hydroxide materials.     

Managed Evolution

Zusammenfassung  Die nachhaltige Weiterentwicklung eines grossen Informatiksystemes ist aufgrund der schwierigen technischen und kommerziellen Randbedingungen eine sehr anspruchsvolle Aufgabe. Einerseits haben diese Informatiksysteme eine Komplexit?t erreicht, deren Folgen immer schwieriger zu beherrschen sind. Andererseits muss ein kontinuierlicher Fluss von neuen Gesch?ftsanforderungen unter hohem Zeit- und Kostendruck implementiert werden. Dabei müssen die Informatiksysteme zu jeder Zeit verfügbar, stabil, verl?sslich und sicher bleiben sowie Effizienz und Wirtschaftlichkeit gew?hrleisten. Damit das IT-Management diese zentrale Aufgabe erfüllen kann, muss eine wirksame Evolutionsstrategie formuliert und umgesetzt werden. Credit Suisse hat für sich die Evolutionsstrategie ,,Managed Evolution“ definiert und implementiert. Dieser Beitrag erkl?rt die Managed Evolution, einen Teil der Umsetzungsinstrumente und die bis heute erreichten Resultate. Diese zeigen messbar, dass die Managed Evolution die erwarteten Erfolge liefert.     

On the Pseudogap State in Y- and La-Type High-Temperature Superconductors: Doping Dependence, Isotope Effects, and Electronic Properties Studied by Neutron Spectroscopy

The doping dependence as well as the oxygen and copper isotope effects on the pseudogap temperature T* were investigated by neutron spectroscopic experiments of the relaxation rate of crystal-field excitations in rare-earth based Y- and La-type high-temperature superconductors. We found three essential results from our truly bulk-sensitive experiments: (1) For all doping levels we had T* > T _c, even in the optimally doped and overdoped regimes. (2) In bilayer high-T _c compounds we observed huge oxygen and copper isotope effects on T*, which give evidence that the pseudogap formation is governed by lattice modes involving both the oxygen and copper ions. In single layer high-T _c compounds, on the other hand, no shift of T* was found for the copper isotope substitution. (3) Our results obtained for all doping levels support the unusual temperature dependence of the gap function in the pseudogap region reported for underdoped Bi-type compounds, i.e., a breakup of the Fermi surface into disconnected arcs in the temperature range T _c < T < T*.     

THE ROLE OF NIOBIUM IN NICKEL-BASED SUPERALLOYS AND CHARACTERIZATION OF PM ALLOY EP741NP

1. IntroductionN iobium 'sprim ary role in superalloysisasa strengthenervia precipitation hardening and via solidsolution strengthening in a lesserextent. N iobium form s M C-type carbides in addition to the gam m adouble prim e (γ')phase N i3N b in iro…