IV. Referate

Ohne Zusammenfassung     

Relative validation of a food frequency questionnaire for national health and nutrition monitoring

Background  

Validation of a food frequency questionnaire (FFQ) is important as incorrect information may lead to biased associations. Therefore the relative validity of an FFQ developed for use in the German Health Examination Survey for Adults 2008-2011 (DEGS) was examined.     

Groove profile modification of blazed gratings by dip coating with hardenable liquids

We modify groove profile of various blazed gratings with groove densities as great as 3600 lines/mm by dip coating with hardenable liquids with the aim of reducing the blaze angle. The groove profiles resulting from coatings with different layer thickness are measured by atomic force microscopy. A highly reproducible blaze angle reduction to as high as a factor of 6 is achieved with mechanically ruled as well as ion-beam-etched holographic blazed gratings. Blaze angles, to as small as 0.7 deg, which are required for vacuum-UV and soft-x-ray applications but can hardly be formed with sufficient groove profile accuracy by direct ruling, are realized with this coating technique.     

Efficiency calibration of the first multilayer-coated holographic ion-etched flight grating for a sounding rocket high-resolution spectrometer

We have fabricated the four flight gratings for a sounding rocket high-resolution spectrometer using a holographic ion-etching technique. The gratings are spherical (4000-mm radius of curvature), large (160 mm x 90 mm), and have a laminar groove profile of high density (3600 grooves/mm). They have been coated with a high-reflectance multilayer of Mo/Si. Using an atomic force microscope, we examined the surface characteristics of the first grating before and after multilayer coating. The average roughness is approximately 3 A rms after coating. Using synchrotron radiation, we completed an efficiency calibration map over the wavelength range 225-245 A. At an angle of incidence of 5 degrees and a wavelength of 234 A, the average efficiency in the first inside order is 10.4 +/- 0.5%, and the derived groove efficiency is 34.8 +/- 1.6%. These values exceed all previously published results for a high-density grating.     

COMPUTER-AIDED CALCULATION OF APPROXIMATE CLOSED-FORM SOLUTIONS FOR LINEAR TRANSIENT HEAT CONDUCTION PROBLEMS IN MULTILAYERED BODIES

A solution procedure, based on the Kantorovich method, is presented for the derivation of approximate closed-form solutions for linear heat conduction problems in multilayered plane and cylindrical bodies using computers. Constant or space dependent initial conditions; linear time dependent boundary conditions of the first, second, or third kind; contact resistances between the layers; and a homogeneous distributed, time dependent volumetric heat source can be considered. The solution procedure is shown suitable for programming. In order to assess the approximate solution obtained, an error criterion is stated. The accuracy of the method is investigated through a numerical and an analytical example.     

Guest Editors' Introduction: Intelligent Transportation and Pervasive Computing

This special issue samples the developing area of pervasive computing in transportation systems through four feature articles and the Spotlight department, which consists of two interviews and two short articles. These contributions were written by automotive industry and academic experts and provide a diversity of views on a range of topics. Although the contributions focus on intelligent vehicular transportation, the technologies discussed also have applications in other transportation systems. This article is part of a special issue on Intelligent Transportation.     

Some properties of the NRTL equation in correlating liquid—liquid equilibrium data

The NRTL equation proposed by Renon and Prausnitz has been discovered to have some properties that may complicate its use. Specifically, there is more than one set of parameters, τ₁₂ and τ₂₁, which fit given solubility data with a fixed value of the nonrandomness parameter. Also, some sets of parameters can predict two different miscibility gaps at a fixed temperature and pressure in a binary system. It is shown that it is possible to predict more than one miscibility gap even in symmetric systems and that this occurs for at least some values of the nonrandomness parameter greater than 0·426, which was the limit for phase separation reported by Renon and Prausnitz.The value of the NRTL equation in correlating and extrapolating equilibrium data of various kinds has been amply demonstrated in the literature. However, some NRTL parameter sets arrived at simply by correlating data may predict the complex physical behavior discussed here.     

Gewinnung molekulareinheitlicher N-Propionyl-oligo-ε-aminocapronsäurepropylamide aus Oligokondensaten durch Gelpermeationschromatographie

N-propionyl-oligo-ε-aminocaproic-acid-propylamides have been prepared by transamidation of caprolactam with propionic acid propylamide. The oligocondensate contains no cyclic compounds, and is nearly free from linear amides with terminal amino or carboxy groups. Variations in the conditions of transamidation change the distribution of chain length. The oligocondensates are separated into individual compounds by gelpermeation chromatography using Sephadex LH-20 and phenol/ethanol/water (1:2.6:1.6 v/v) as eluant. The oligoamides have been isolated up to the pentadecamer. Sufficient amounts of material for physico-chemical measurements are easily obtained by this procedure.