Noise simulations of flap devices for wind turbine rotors

The rotor of a large diameter wind turbine experiences more substantial and more dynamic loads due to the fluctuating and heterogeneous wind field. The project SmartBlades 2.0 investigated rotor blade design concepts that alleviate aerodynamic loading using active and passive mechanisms. The present work evaluates the acoustics of the two load alleviating concepts separately, an inboard slat and an outboard flap, using the Fast Random Particle Mesh/Fast Multipole Code for Acoustic Shielding (FRPM/FMCAS) numerical prediction toolchain developed at DLR with input from the averaged flow field from RANS. The numerical tools produce a comparable flap side-edge noise spectrum with that of the measurement conducted in the Acoustic Wind Tunnel Braunschweig (AWB). The validated FRPM/FMCAS was then used to analyze the self-noise from a slat at the inboard section of a rotor blade with a 44.45 m radius and compared with that from the outboard trailing edge. Furthermore, the rotational effect of the rotor was included in the post-processing to emulate the noise observed at ground level. The findings show an increase in the slat's overall sound pressure level and a maximum radiation upwind of the wind turbine for the case with the largest wind speed that represents the off-design condition. In operational conditions, the slat adds at most 2 dB to the overall sound pressure level. The toolchain evaluates wind turbine noise with conventional or unconventional blade design, and the problem can be scaled up for a full-scale analysis. As such, the tools presented can be used to design low-noise wind turbines efficiently.     

Determination of fringe order in white-light interference microscopy

Combining phase and coherence information for improved precision in white-light interference microscopy requires a robust strategy for dealing with the inconsistencies between these two types of information. We correct for these inconsistencies on every measurement by direct analysis of the difference map between the coherence and the phase profiles. The algorithm adapts to surface texture and noise level and dynamically compensates for optical aberrations, distortions, diffraction, and dispersion that would otherwise lead to incorrect fringe order. The same analysis also provides the absolute height data that are essential to relational measurements between disconnected surfaces.     

Relation of level of exercise, age, and weight-cycling history to weight and eating concerns in male and female runners.

Examined the association between level of exercise and degree of weight preoccupation among 2,459 male and 1,786 female runners (aged 15–89 yrs) as well as risk factors posited to influence weight and eating concerns (WECs) in the general population. Ss completed a questionnaire on WECs in a national running magazine. 8% of the males and 24% of the females had symptomatic scores on the Eating Attitudes Test (EAT) by D. M. Garner et al (see record 1983-22427-001). Exercise level, defined as weekly running mileage, was positively associated with excessive WECs in males but not in females. Both sexes with a history of weight cycling were more likely to have symptomatic EAT scores than those with no such history. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patterns of information transfer among engineers and applied scientists in complex organizations

This review discusses studies of informal communication of scientific and technical information published in the American management literature between 1976 and 1982. While investigated formerly by information scientists, the subject has been mentioned only infrequently in the literature and abstracts of information science in recent years. Management scientists view the informal information transfer as a special type of organizational communication. Among the papers reviewed, special attention is accorded to the publications byTushman who has extended and developedAllen's approach. The implications of the insights gained for the information worker and information scientist are discussed in the conclusions.     

Uptake of diet resveratrol into the human low-density lipoprotein. Identification and quantification of resveratrol metabolites by liquid chromatography coupled with tandem mass spectrometry

In this paper, a sensitive, precise, and selective analytical method has been developed for the identification and quantification of resveratrol metabolites in human low-density lipoprotein (LDL) after moderate consumption of red wine, using high-performance liquid chromatography electrospray in tandem mass spectrometry (LC-ESI-MS/MS). From different extraction procedures tested, solid-phase extraction was selected to minimize matrix effects reaching the highest sensitivity. Standard calibration curves prepared in human LDL for trans-resveratrol were linear over a range of 0.44-438.59 pmol/mL. The accuracy and interassay precision of this LC-MS/MS assay for resveratrol showed a coefficient of variation of <6.0%. The method allows detection and quantification limits for resveratrol in LDL at 0.15 and 0.44 pmol/mL, respectively. Results to date indicate that resveratrol metabolites were incorporated into LDL after a moderate intake of red wine. The metabolites identified in LDL were trans-resveratrol-3-O-glucuronide, cis-resveratrol-3-O-glucuronide, and cis-resveratrol-3-O-glucoside, as well as free trans-resveratrol. To our knowledge, it is the first time that a polyphenol from red wine, specifically resveratrol, has been identified in human LDL after moderate intake of red wine. Furthermore, these findings suggest that these compounds may deliver their antioxidant effect to LDL.     

Chemical, technological, and nutritional characteristics of two lines of "farro" (Triticum turgidum ssp. dicoccum)

In recent years, the renewed interest for foods with a natural image has increased the demand for dry pasta produced from "hulled" wheat such as the Triticum turgidum ssp. dicoccum, also known as "farro". In order to contribute to the general knowledge, two lines of farro were considered in this study. To have a comparison, an old cultivar of Triticum turgidum ssp. durum (Senatore Cappelli) in addition to a commercial semolina were also examined. All semolina samples were used to produce pasta samples. Results showed some differences among pasta samples that seem to be due not to the presence of specific protein subunits but especially to the quantitative ratio between the different subunits. Results also reconfirmed the role played by the drying technology that is able to affect the sensory characteristics of pasta products.     

Supported membrane nanodevices

Supported membrane nanodevices are based on natural or artificial ion channels embedded in a lipid membrane deposited on a chip wafer. Membrane conductance is modulated by biorecognitive events, with the use of intrinsic binding sites of the ion channel or via artificial sites fused to the channel protein. Artificial ion gates are constructed by coupling a specific ligand for the analyte near the channel entrance or a site important to triggering channel conformation. The binding event leads to the closure of the ion channel or induces a conformational change of the channel, reducing the ion flux. The signal transduced from the device is the decrease in the ion flux-induced electron current at a silver-silver chloride electrode at ultimate single-molecule sensitivity. Among the natural ion channels, gramicidin A, a transport antibiotic, was found to be most suitable, and thus was used by AMBRI, Australia, to set up prototypes of membrane biochips, using self-association of the dimer. Covalent dimerization-based devices, developed by the Vienna group, make use of the down-regulation of the permanently open membrane-spanning bisgramicidine ion channel. The reactive group at the C-terminus, a hydroxy group, allows precise coupling of the analyte-binding moiety in gramicidin as well as bisgramicidin. The device is set up with bilayer membranes deposited on apertures of a hydrophobic frame structure produced via microlithography, facing an aqueous or hydro-gel micro-environment on both sides, constructing black lipid membranes or patch-clamp devices "on chip." The setup of the device needs gel membrane supports that allow membrane formation and contribute to the stability of the bilayer by exposure of functional groups that promote electrostatic interaction and formation of hydrogen bridges and enable the introduction of covalent spacers and anchors. Photo-cross-linked polyvinylpyrrolidone and polyacrylamide, electropolymerized polydiaminobenzene and coated agarose, as well as various chemical modifications of these polymers, were employed as membrane supports. With optimized assemblies, the membrane support did allow the formation of stable bilayer membranes, proved by "gigaseal" (electrical sealing with giga-ohm resistance) to be free of any point defects in the lipid assembly. Supports with and without hydrophilic and hydrophobic anchors were studied with reference to promoting the formation of a self-assembled membrane, to their electric resistance, and to the capability to insert functional ionophores. All components, including novel chemically engineered ion channels, novel amphiphilic lipids, a microlithographically designed chip, isolating polymer frames, and a hydrogel membrane support, are combined in the new bionanodevice. Sensitivity and specificity were proved, for example, with the use of an antibody-antigen couple down-regulating the ion flux through the membrane channel. Single ion channels incorporated in the supported lipid bilayer gave stable signals at an operational stability of several hours, which is already sufficient to test and screen for membrane receptors but still insufficient to use this device as a sensor for off-site application. Further optimization to increase operational and storage stability is done by a number of groups to allow a broad application of these devices.     

Gender-related consequences of Internet use perceived by parents in a representative quota sample of adolescents

Only few studies have investigated gender differences in consequences of adolescent Internet use in a general population sample. In this study, we surveyed a representative German quota sample of N=1744 adolescents aged between 14 and 17 years and their caregivers with standardised questionnaires. Parents’ reports showed significant differences between male and female youth in 8 out of 10 problem areas (summarised in a ‘difficulties index’, Cronbach's alpha=0.89) caused by adolescent Internet use. According to parents’ assessment, male adolescents neglected school obligations and friendships outside the Internet more frequently than female adolescents. Compared to girls, boys spent more time and money using the Internet, regarded media use as more important, set wrong priorities in selecting online content, and rather ran into cost traps or legal consequences. More parents of boys than of girls observed adverse effects on adolescents’ physical and mental development. Both parents and adolescents consistently reported excessive media use more frequently for boys. By conducting a multiple linear regression analysis for the full sample, approximately one-third (34%) of the variance in the ‘difficulties index’ was explained by frequency of excessive Internet use. The results highlight the importance of gender-related analyses regarding the consequences of adolescent Internet use.