Causes of failure of airship shed

The causes of the collapse of airship shed, which was being taken down at Niediergorsdorf, are discussed. This shed, which was built of iron, was 184 m long, 28 m high, and 35 m wide. The demolition of the shed had been assigned to unskilled men who proceeded to remove certain key structural supports, leaving the structure in such a condition that relatively small eccentricities of the columns or spans or of lateral forces could easily have caused the columns or spans to break down. A small gust of wind would have perhaps sufficed to bring the building down. An analysis is also given of the suction effects on the roof of an air shed in Staaken. The damage to this shed, which occurred during a storm, was due to the fact that the shed had no opening in its top for equalizing the air pressure within and without. The location of the plates blown off the roof correspond to the point of greatest suction

Best rectangular and I-shaped cross sections for airplane wing spars

Equations are presented with which to determine spar cross-sections

Crystal and magnetic structure of substituted lanthanum cobaltites

The crystal and magnetic structures of the lanthanum cobaltites La0.6Sr0.4CoO3, La0.6Sr0.4Co0.9Fe0.1O3 and La0.6Ba0.4Co0.9Fe0.1O3 have been studied by neutron powder diffraction at temperatures of 2, 300 and 900 K. All compounds undergo a phase transition from cubic to rhombohedral structure. Below the room temperature La0.6Sr0.4CoO3 becomes ferromagnetic while for the components with 10% Fe substituted for Co, we found an antiferromagnetic order

Shear Thickening and Scaling of the Elastic Modulus in a Fractal Colloidal System with Attractive Interactions

Dilute oil dispersions of fractal carbon black particles with attractive Van der Waals interactions display continuous shear thickening followed by shear thinning at high shear rates. The shear thickening transition occurs at $\dot\gamma_{c}\approx 10^{2}-10^{3}s^{-1}$ and is driven by hydrodynamic breakup of clusters. Pre-shearing dispersions at shear rates $\dot\gamma>\dot\gamma_{c}$ produces enhanced-modulus gels where $G' \sim \sigma_{pre-shear}^{1.5-2}$ and is directly proportional to the residual stress in the gel measured at a fixed sample age. The observed data can be accounted for using a simple scaling model for the breakup of fractal clusters under shear stress.Comment: 5 pages, 5 figures; v2: treating low shear rate date separately; edited title; reworked figure

Band structures of rare gas solids within the GW approximation

Band structures for solid rare gases (Ne, Ar) have been calculated using the GW approximation. All electron and pseudopotential ab initio calculations were performed using Gaussian orbital basis sets and the dependence of particle-hole gaps and electron affinities on basis set and treatment of core electrons is investigated. All electron GW calculations have a smaller particle-hole gap than pseudopotential GW calculations by up to 0.2 eV. Quasiparticle electron and hole excitation energies, valence band widths and electron affinities are generally in very good agreement with those derived from optical absorption and photoemission measurements.Comment: 7 pages 1 figur

Application of current in situ hybridization techniques for grape phylloxera (Daktulosphaira vitifoliae, Fitch) and grapevine (Vitis spp. L.)

In situ hybridization and in situ PCR directly localize specific DNA and RNA sequences in tissues. To exactly focus on the processes occurring on cell- or tissue level, in situ techniques can be efficiently employed. Recent advances in viticultural research in the fields of genomics, proteomics and metabolomics are likely to employ these techniques to link DNA- or mRNA sequence information to physiological traits and processes occurring in the grapevine. In this paper, we present a range of possibilities for in situ techniques that can be applied in grapevine research. Two examples covering in situ PCR of grapevine roots and in situ hybridization of grape phylloxera will be given for illustration. Moreover, key steps of the techniques are discussed, which may be helpful to researchers aiming to employ in situ hybridization or in situ PCR.

Biosensing platform combining label-free and labelled analysis using Bloch surface waves

Bloch surface waves (BSW) propagating at the boundary of truncated photonic crystals (1D-PC) have emerged as an attractive approach for label-free sensing in plasmon-like sensor configurations. Due to the very low losses in such dielectric thin film stacks, BSW feature very low angular resonance widths compared to the surface plasmon resonance (SPR) case. Besides label-free operation, the large field enhancement and the absence of quenching allow utilizing BSW coupled fluorescence detection to additionally sense the presence of fluorescent labels. This approach can be adapted to the case of angularly resolved resonance detection, thus giving rise to a combined label-free / labelled biosensor platform. It features a parallel analysis of multiple spots arranged as a one-dimensional array inside a microfluidic channel of a disposable chip. Application of such a combined biosensing approach to the detection of the Angiopoietin-2 cancer biomarker in buffer solutions is reported