Chemical milling solution produces smooth surface finish on aluminum

Elementary sulfur mixed into a solution of caustic soda and salts produces an etchant which will chemically mill end-grain surfaces on aluminum plate. This composition results in the least amount of thickness variation and pitting

A drying-yard tray lifter /

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Ericson fluctuations in an open, deterministic quantum system: theory meets experiment

We provide numerically exact photoexcitation cross sections of rubidium Rydberg states in crossed, static electric and magnetic fields, in quantitative agreement with recent experimental results. Their spectral backbone underpins a clear transition towards the Ericson regime.Comment: 4 pages, 3 figures, 1 tabl

Residual Symmetries in the Spectrum of Periodically Driven Alkali Rydberg States

We identify a fundamental structure in the spectrum of microwave driven alkali Rydberg states, which highlights the remnants of the Coulomb symmetry in the presence of a non-hydrogenic core. Core-induced corrections with respect to the hydrogen spectrum can be accounted for by a perturbative approach.Comment: 7 pages, 2 figures, to be published in Europhysics Letter

Non-dynamic origin of the acoustic attenuation at high frequency in glasses

The sound attenuation in the THz region is studied down to T=16 K in glassy glycerol by inelastic x-ray scattering. At striking variance with the decrease found below 100 K in the GHz data, the attenuation in the THz range does not show any T dependence. This result i) indicates the presence of two different attenuation mechanisms, active respectively in the high and low frequency limits; ii) demonstrates the non-dynamic origin of the attenuation of THz sound waves, and confirms a similar conclusion obtained in SiO2 glass by molecular dynamics; and iii) supports the low frequency attenuation mechanism proposed by Fabian and Allen (Phys.Rev.Lett. 82, 1478 (1999)).Comment: 3 pages, 5 Figures, To be published in PR

ACUTE EFFECTS OF STRENGTH TRAINING ON RUNNING ECONOMY

Sequencing strength training before aerobic conditioning is practised without empirical support. This study explored the acute effects of strength training on running economy and 3-D kinematics in five males. Running was performed on a treadmill at 12 and 14 km/h on three separate occasions. Trial 1 and 2 involved no strength training with data used to assess response stability of the variables. Before Trial 3, three sets of three repetitions at 85% of 1 repetition maximum of squat, bench press and deadlift with 3-5 minutes of rest were performed. Compared to Trial 2 no significant differences were observed when strength training was performed. Only a tendency of increased knee flexion (4.5°) at foot strike at the higher running velocity was observed. This suggests that running kinematics were changed exposing participants to long-term chronic injuries

TRANSMISSION OF VIBRATION ABOUT THE KNEE

The purpose of this study was to examine and describe effects of knee flexion angle, stance width and vibration platform frequency on the transmission of vertical acceleration about the knee. Fifteen adults were exposed to various vibration conditions while standing on a side-to-side vibration platform. Vertical acceleration data, expressed as transmission, were shown to be attenuated for all vibration conditions. A larger degree of knee flexion however, was conducive to greater attenuation about the knee. Such information may be used to develop vibration training programs with a more thorough understanding of effects of vibration

Radiosektion: Computertomographie-assistierte Rekonstruktion eines erweiterten Suizids

Zusammenfassung: Erweiterte Suizide durch Schusswaffen sind häufig durch eine sorgfältige Fundortanalyse zu klären. Im dargestellten Fall wurde eine 38-jährige Frau in Rückenlage auf dem Bett im Schlafzimmer aufgefunden. Im Bereich der linken Brust fand sich eine rundliche Einschusswunde. Neben dem Bett wurde eine Schusswaffe gefunden. Im Wohnzimmer lag ein 40-jähriger Mann in Bauchlage auf der Erde in einer größeren Blutlache. Ein unvollendeter Abschiedsbrief fand sich auf dem Esstisch. Nach der äußeren Leichenschau am Fundort erfolgte eine Röntgenschichtuntersuchung. Hierdurch wurde bei der Frau ein absteigender Schusskanal von der linken Brust durch die Herzspitze dargestellt. Das Projektil konnte im Rippenzwischenraum nahe der Wirbelsäule lokalisiert werden. Bei dem Mann wurden ein Schusskanal durch den harten Gaumen und ein Projektil in der Schädelhöhle festgestellt; dieses lag nicht in einer Linie mit dem Schusskanal, sodass ein "Ringelschuss" diagnostiziert wurde. Die nachfolgende Sektion beider Leichen bestätigte die Befunde. Die bei der Autopsie sichergestellten Projektile konnten durch ballistische Untersuchungen der am Ereignisort sichergestellten Waffe zugeordnet werde

Absolute frequency measurements of 85Rb nF7/2 Rydberg states using purely optical detection

A three-step laser excitation scheme is used to make absolute frequency measurements of highly excited nF7/2 Rydberg states in 85Rb for principal quantum numbers n=33-100. This work demonstrates the first absolute frequency measurements of rubidium Rydberg levels using a purely optical detection scheme. The Rydberg states are excited in a heated Rb vapour cell and Doppler free signals are detected via purely optical means. All of the frequency measurements are made using a wavemeter which is calibrated against a GPS disciplined self-referenced optical frequency comb. We find that the measured levels have a very high frequency stability, and are especially robust to electric fields. The apparatus has allowed measurements of the states to an accuracy of 8.0MHz. The new measurements are analysed by extracting the modified Rydberg-Ritz series parameters.Comment: 12 pages, 5 figures, submitted to New. J. Phy

Decision support for evaluating energy demand in vinification processes using fuzzy sets theory

The current trend associated with high energy demand, depletion of energy reserves and low potential of renewable energy sources linked with strong industrial growth, is increasingly becoming unsustainable. As a result, production costs have increased considerably in the process industries, mainly owing to skewed energy demand and supply realities. A feasible strategy for meeting these challenges is to reduce energy consumption per unit throughput. However, to obtain a workable solution, decision makers may have to deal with energy management variables that are ambiguous, which makes solving the energy minimization problem with conventional numerical approaches very difficult. In this paper, we consider an alternative approach based on fuzzy logic to qualitatively evaluate the energy demand associated with an industrial cooling process. The model was formulated based on Mamdani fuzzy logic inferencing and implemented in MATLAB 6.5 via the Fuzzy Logic toolbox. The energy demands pertaining to specific variables were independently estimated, followed by an estimate of the overall energy consumption. The procedure is demonstrated via a case study of cooling at the maceration stage of a vinification process in the wine industry