Elektronische Geruchsuntersuchung von Hölzern

Zusammenfassung: Ber Hoizgeruch wurde bisiang bei der Bestimmung der Holzart und Beschreibung des Holzzustandes nur marginal berücksichtigt. Mit Hilfe einer Anlage mit einer neuen Kombination von Gassensorarrays (Serien von gasempfindlichen Metallhalbleitern), verbunden mit neuronalen Netzen, wurden einheimische Nadel- und Laubhölzer sowie tropische Laubhölzer auf ihre Unterscheidbarkeit getestet. Eine gezielte Datenbearbeitung ermöglicht es, auch bisher schwer zu unterscheidende Arten über den Geruch zu trennen. Neben der Abhängigkeit des Geruches von der Holzart und weiterer Faktoren (mit dem Ort der Probenentnahme im Baum zusammenhängend) werden auch allgemeine Anwendungsmöglichkeiten des Systems kurz diskutier

On Learning Monotone DNF Formulae under Uniform Distributions

AbstractWe show how to learn in polynomial time monotone d-term DNF formulae (formulae in disjunctive normal form with at most d terms) using positive examples drawn from a distribution that is a generalization of the uniform distribution

Open questions on prominences from coordinated observations by IRIS, Hinode, SDO/AIA, THEMIS, and the Meudon/MSDP

Context. A large prominence was observed on September 24, 2013, for three hours (12:12 UT -15:12 UT) with the newly launched (June 2013) Interface Region Imaging Spectrograph (IRIS), THEMIS (Tenerife), the Hinode Solar Optical Telescope (SOT), the Solar Dynamic Observatory Atmospheric Imaging Assembly (SDO/AIA), and the Multichannel Subtractive Double Pass spectrograph (MSDP) in the Meudon Solar Tower. Aims. The aim of this work is to study the dynamics of the prominence fine structures in multiple wavelengths to understand their formation. Methods. The spectrographs IRIS and MSDP provided line profiles with a high cadence in Mg II and in Halpha lines. Results. The magnetic field is found to be globally horizontal with a relatively weak field strength (8-15 Gauss). The Ca II movie reveals turbulent-like motion that is not organized in specific parts of the prominence. On the other hand, the Mg II line profiles show multiple peaks well separated in wavelength. Each peak corresponds to a Gaussian profile, and not to a reversed profile as was expected by the present non-LTE radiative transfer modeling. Conclusions. Turbulent fields on top of the macroscopic horizontal component of the magnetic field supporting the prominence give rise to the complex dynamics of the plasma. The plasma with the high velocities (70 km/s to 100 km/s if we take into account the transverse velocities) may correspond to condensation of plasma along more or less horizontal threads of the arch-shape structure visible in 304 A. The steady flows (5 km/s) would correspond to a more quiescent plasma (cool and prominence-corona transition region) of the prominence packed into dips in horizontal magnetic field lines. The very weak secondary peaks in the Mg II profiles may reflect the turbulent nature of parts of the prominence.Comment: 15 pages, 14 figure

Untersuchungen zum Einfluß ausgewählter Strukturparameter von Spanplatten auf die Schallemission bei Biegebelastung

Zusammenfassung: An einschichtigen, labortechnisch hergestellten Spanpiatten ausPinus radiata wurde der Einfluß der mittleren Plattenrohdichte und des Festharzanteiles auf die mechanischen Eigenschaften und die Schallemission geprüft. Die Impulssumme steigt mit zunehmendem Belastungsgrad an. Eine Erhöhung von Rohdichte und Festharzanteil bewirken einen Anstieg der freigesetzten Impulse. Zwischen der Impulssumme bei 40% der Bruchlast und dem E-Modul besteht eine straffe Korrelation, die allerdings auch durch die starke Dichte- bzw. Festigkeitsspreizung des Versuchsmaterials mitbedingt is

Unhappiness, health and cognitive ability in old age

Background To test whether scores on depression inventories on entry to a longitudinal study predict mental ability over the next 4–16 years. Method Associations between scores on the Beck Depression Inventory and on tests of intelligence, vocabulary and memory were analysed in 5070 volunteers aged 49–93 years after differences in prescribed drug consumption, death and drop-out, sex, socio-economic advantage and recruitment cohort effects had also been considered. Results On all cognitive tasks Beck scores on entry, even in the range 0–7 indicating differences in above average contentment, affected overall levels of cognitive performance but not rates of age-related cognitive decline suggesting effects of differences in life satisfaction rather than in depression. Conclusions A new finding is that, in old age, increments in life satisfaction are associated with better cognitive performance. Implications for interpreting associations between depression inventory scores and cognitive performance in elderly samples are discussed

Ergonomic assessment and low back pain among commercial fishermen

Low back pain (LBP) is a significant problem for commercial fishermen. Little research has been done to investigate the ergonomic stress of occupational fishing tasks, and no previous study has explored the link between low back stress and LBP in fishing. This study quantified low back stresses during commercial crab and gillnet fishing tasks and determined the association between those stresses and LBP occurrences reported in a prospective cohort study of North Carolina commercial fishermen conducted April 1999 to October 2001. Two ergonomic methods measured the percent of time fishermen were exposed to low back stress in a sample of 29 commercial fishermen. Fishing task frequency was evaluated in a telephone questionnaire with cohort crab pot and gillnet fishermen (n=105). Multivariate generalized Poisson regression modeled the occurrence rate ratios (RR, 95% CI) of LBP that limited or interrupted work (severe LBP) by percent time exposed to high low back stress and self-reported task. The rate of severe LBP was 0.69 per 1000 person-days (95% CI: 0.47, 0.90). Age, years of experience and previous severe LBP were associated with severe LBP. Handling heavy loads during loading and unloading produced high compression (3400 to 5315 Newtons) and lifting index values (3.0 to 5.4), but contributed little to overall work iv time (0-14%). Unloading the boat with or without use of a lifting aid was associated with an increased rate of severe LBP. Sorting catch, due to the large portion of time in static, nonneutral trunk postures (83% task time, 27-53% total work time), was associated with an increased rate of LBP (1.80 95% CI: 0.78, 4.13). Overall, increased rates of LBP were associated with the percent of time fishermen were exposed to awkward postures, spine compression >3400 Newtons, and NIOSH lifting index >3.0. Our results demonstrate that neither fishing task frequency nor ergonomic measure alone consistently predict LBP. Age, history of LBP, and self-selection out of tasks were likely important contributors to the patterns of low back stress and outcomes we observed. Research should involve fishermen in future intervention studies to account for these behaviors and increase adoption and diffusion of beneficial interventions

Human urine certified reference material CZ 6010: creatinine and toluene metabolites (hippuric acid and o-cresol) and a benzene metabolite (phenol)

A reference material for the biological monitoring of occupational exposure to toluene, benzene and phenol was prepared. O-cresol and hippuric acid (metabolites of toluene) are used for the biological monitoring of occupational exposure to toluene. Phenol, a metabolite of benzene, is used for the biological monitoring of exposure to benzene, but phenol can of course also be used as an indicator of exposure to phenol as well. The reference material (RM) used for the determination of these metabolites was prepared by freeze-drying pooled urine samples obtained from healthy persons occupationally exposed to toluene and those taking part in an inhalation experiment. Tests for homogeneity and stability were performed by determining urine concentrations of o-cresol, hippuric acid, creatinine and phenol. To investigate the stability of the RM, the urinary concentrations of o-cresol and phenol were monitored for eighteen months using GC and HPLC, while those of hippuric acid and creatinine were followed for five and six years, respectively, using HPLC. Analysis of variance showed that the concentrations did not change. The certified concentration values (and their uncertainties) of the substances in this reference material (phenol concentration c=6.46+/-0.58 mg l(-1); o-cresol concentration c=1.17+/-0.15 mg l(-1); hippuric acid concentration c=1328+/-30 mg l(-1); creatinine concentration c=0.82+/-0.10 g l(-1)) were evaluated via the interactive statistical programme IPECA