Experimental determination of the lidar overlap profile with Raman lidar

The range-dependent overlap between the laser beam and the receiver field of view of a lidar can be determined experimentally if a pure molecular backscatter signal is measured in addition to the usually observed elastic backscatter signal, which consists of a molecular component and a particle component. Two methods, the direct determination of the overlap profile and an iterative approach, are presented and applied to a lidar measurement. The measured overlap profile accounts for actual system alignment and for all system parameters that are not explicitly known, such as actual laser beam divergence and spatial intensity distribution of the laser light.     

On the kinetics of the autoxidation of fats. II. Monounsaturated substrates

The autoxidation of methyl oleate and oleic acid shows some differences as compared to the autoxidation of linoleate,e.g., the formation of water at an early stage. Linearization of experimental data on the autoxidation to high oxidation degrees of methyl oleate and other monounsaturated substrates shows that the rate equations previously derived for methyl linoleate in the range of 1–25% oxidation are valid, provided the correct expression for the remaining unreacted substrate is used. With monounsaturated substrates, part of the oxygen is consumed by a secondary oxidation reaction almost from the beginning, and only a certain constant fraction α of the total O₂ consumption is consumed in hydroperoxide formation. The fraction α is different for methyl oleate, oleyl alcohol, oleic acid andcis 9-octadecene, but the rate constant for the hydroperoxide formation is the same for all of them when experimental conditions are the same. The main difference between oleate and linoleate autoxidation is the much faster decomposition of the oleate hydroperoxides relative to their slow formation.     

Mullite-type EMBO4: synthesis,structural, optical,and vibrational properties of rare tin(II) borates with M = Al and Ga

Metal tin-(II)-borates are rarely studied mainly due to the susceptibility of either oxidation into tin(IV) or disproportionation into elemental tin(0) and tin(IV). We report mullite-type SnAlBO₄ and SnGaBO₄ ceramics produced by conventional solid-state synthesis in sealed quartz tubes at low pressure of 10^–7 MPa. Both compounds are isostructural to PbAlBO₄ as confirmed by Rietveld refinements of powder X-ray data. The crystal structures are highly influenced by the stereochemical activity of the 5s² lone electron pair of the Sn²⁺ cation measured by the Wang–Liebau eccentricity parameter. To further consolidate the structural features ¹¹⁹Sn Mössbauer, solid state NMR, Raman, IR and UV/vis spectroscopic measurements are performed. The ¹¹⁹Sn Mössbauer isomer shifts and the quadrupole splitting values confirm the SnO₄ coordination and Sn(II) valence states. Solid state ¹¹B, ²⁷Al and ¹¹⁹Sn NMR spectra provided insights into the local crystal-chemical environment. The vibrational properties are discussed from group theoretical analysis to mode assignments. SnAlBO₄ and SnGaBO₄, respectively, possess an electronic band gap of 3.73(9) and 3.21(4) eV calculated from the diffuse reflectance UV/Vis spectra.     

The n = 3 member of the SrCoO(3n − 1)/n series of layered oxygen-defect perovskites

Topotactic oxygen deintercalation from cubic perovskite oxide SrCoO_3 − δ (δ < 0.25) is realized in a controlled way at low temperatures. Annealing in air at 200 < T < 275 °C results in a three-phase region within 0.25 < δ < 0.50. Two of the phases are known previously, namely SrCoO_2.5, a phase with an orthorhombic brownmillerite-type (BM) structure, and SrCoO_2.75 (T1), a phase with a slight tetragonal distortion from cubic symmetry. The third phase (T2) has a strong tetragonal distortion, and appears to be the missing n = 3 member of the SrCoO_{(3n − 1)/n} series. Once the overall oxygen content reaches the value of (3 − δ)_aver = 2.68(1), the T1-to-T2 phase conversion proceeds at constant (3 − δ)_aver. A more pronounced evolution of the c_T2 lattice parameter as compared to the a_T2 parameter implies a layered oxygen-vacancy-ordered structure for T2 with some flexibility for oxygen-content variation, in the style of the BM phase.     

Sensory and chemical characterisation of fats used as spreads on bread

Ten dairy fat or margarine-based spreads with 40, 60 or 80% fat, were compared pairwise for their similarity/dissimilarity. The sensory profiles, fatty acid compositions and NaCl contents were also determined. In multidimensional scaling analysis, the three dimensions obtained distinguished between 1) the 80% spreads containing mainly dairy fat vs. others, 2) the spreads containing 40% fat vs. others, and 3) certain individual samples. Polynsaturated vs. saturated fatty acids described dimension I (butter/notbutter), whereas the monounsaturated fatty acids were related to dimensions II and III. The P/S ratios ranged from 0.03 to 2.09. From a sensory viewpoint the major choice offered to the consumers seems to be the one between traditional spreads containing 80% dairy fat and all the remaining spreads.     

On the design and analysis of continuous sandwich panels

Interaction between the bending moment and support reaction introduces new failure modes at intermediate supports of continuous sandwich panels. Two different loading cases have to be separated in the design. Positive support reaction causes a compressive contact pressure between the supporting structure and sandwich panel, and negative support reaction tensile forces in the fasteners of the panels. In the paper, the loading case named the positive support reaction is studied by means of analytical models, numerical analyses and experimental results. The analyses result in recommendations for the design at the serviceability state.     

Lung inflammation and genotoxicity following pulmonary exposure to nanoparticles in ApoE-/- mice

Background  

The toxic and inflammatory potential of 5 different types of nanoparticles were studied in a sensitive model for pulmonary effects in apolipoprotein E knockout mice (ApoE^-/-). We studied the effects instillation or inhalation Printex 90 of carbon black (CB) and compared CB instillation in ApoE-/- and C57 mice. Three and 24 h after pulmonary exposure, inflammation was assessed by mRNA levels of cytokines in lung tissue, cell composition, genotoxicity, protein and lactate dehydrogenase activity in broncho-alveolar lavage (BAL) fluid.     

Comparing two burnout interventions: Perceived job control mediates decreases in burnout.

This quasi-experimental study compared the effects of two rehabilitation interventions on burnout and perceived job conditions during a 1-year intervention among female white-collar workers. The participatory intervention (n = 20), involving rehabilitation activities that focused on the individual as well as on individual-organizational levels, assessed exhaustion, cynicism and perceived job control during a 1-year period. Increased job control served as a mechanism through which exhaustion and cynicism decreased in this intervention. The traditional intervention (n = 32), involving rehabilitation activities focusing mainly on the individual level, resulted in a reduction in time pressures during one year. Furthermore, both interventions improved perceived workplace climate. Compared to the traditional approach, the participatory intervention was a more effective strategy for treating burnout. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automation in future air traffic management: effects of decision aid reliability on controller performance and mental workload

Future air traffic management concepts envisage shared decision-making responsibilities between controllers and pilots, necessitating that controllers be supported by automated decision aids. Even as automation tools are being introduced, however, their impact on the air traffic controller is not well understood. The present experiments examined the effects of an aircraft-to-aircraft conflict decision aid on performance and mental workload of experienced, full-performance level controllers in a simulated Free Flight environment. Performance was examined with both reliable (Experiment 1) and inaccurate automation (Experiment 2). The aid improved controller performance and reduced mental workload when it functioned reliably. However, detection of a particular conflict was better under manual conditions than under automated conditions when the automation was imperfect. Potential or actual applications of the results include the design of automation and procedures for future air traffic control systems.     

Automatic extraction of brain surface and mid-sagittal plane from PET images applying deformable models

In this study, we propose and evaluate new methods for automatic extraction of the brain surface and the mid-sagittal plane from functional positron emission tomography (PET) images. Designing methods for these segmentation tasks is challenging because the spatial distribution of intensity values in a PET image depends on the applied radiopharmaceutical and the contrast to noise ratio in a PET image is typically low. We extracted the brain surface with a deformable model which is based on a global optimization algorithm. The global optimization allows reliable automation of the extraction task. Based on the extracted brain surface, the mid-sagittal plane was determined. The method was tested with the image of the Hoffman brain phantom (FDG) and the images from the brain studies with the FDG (17 images) and the C11-Raclopride tracers (4 images). In addition to the brain surfaces, we applied the deformable model for extraction of the coarse cortical structure based on the tracer uptake from FDG-PET brain images. The proposed segmentation methods provide a promising direction for automatic processing and analysis of PET brain images.