Aeroservoelastic design definition of a 20 MW common research wind turbine model

Wind turbine upscaling is motivated by the fact that larger machines can achieve lower levelized cost of energy. However, there are several fundamental issues with the design of such turbines, and there is little public data available for large wind turbine studies. To address this need, we develop a 20 MW common research wind turbine design that is available to the public. Multidisciplinary design optimization is used to define the aeroservoelastic design of the rotor and tower subject to the following constraints: blade‐tower clearance, structural stresses, modal frequencies, tip‐speed and fatigue damage at several sections of the tower and blade. For the blade, the design variables include blade length, twist and chord distribution, structural thicknesses distribution and rotor speed at the rated. The tower design variables are the height, and the diameter distribution in the vertical direction. For the other components, mass models are employed to capture their dynamic interactions. The associated cost of these components is obtained by using cost models. The design objective is to minimize the levelized cost of energy. The results of this research show the feasibility of a 20 MW wind turbine and provide a model with the corresponding data for wind energy researchers to use in the investigation of different aspects of wind turbine design and upscaling. Copyright © 2016 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134256/1/we1970.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134256/2/we1970_am.pd

The effect of enteral bolus feeding on regional intestinal oxygen saturation in preterm infants is age-dependent:a longitudinal observational study

Background The factors that determine the effect of enteral feeding on intestinal perfusion after preterm birth remain largely unknown. We aimed to determine the effect of enteral feeding on intestinal oxygen saturation (r(int)SO(2)) in preterm infants and evaluated whether this effect depended on postnatal age (PNA), postmenstrual age (PMA), and/or feeding volumes. We also evaluated whether changes in postprandial r(int)SO(2) affected cerebral oxygen saturation (r(c)SO(2)). Methods In a longitudinal observational pilot study using near-infrared spectroscopy we measured r(int)SO(2) and r(c)SO(2) continuously for two hours on postnatal Days 2 to 5, 8, 15, 22, 29, and 36. We compared preprandial with postprandial values over time using multi-level analyses. To assess the effect of PNA, PMA, and feeding volumes, we performed Wilcoxon signed-rank tests or logistic regression analyses. To evaluate the effect on r(c)SO(2), we also used logistic regression analyses. Results We included 29 infants: median (range) gestational age 28.1 weeks (25.1-30.7) and birth weight 1025 g (580-1495). On Day 5, r(int)SO(2) values decreased postprandially: mean (SE) 44% (10) versus 35% (7), P = .01. On Day 29, r(int)SO(2) values increased: 44% (11) versus 54% (7), P = .01. Infants with a PMA >= 32 weeks showed a r(int)SO(2) increase after feeding (37% versus 51%, P = .04) whereas infants with a PMA = 32 weeks when greater volumes of enteral feeding are tolerated. We speculate that at young gestational and postmenstrual ages preterm infants are still unable to increase intestinal oxygen saturation after feeding, which might be essential to meet metabolic demands. Trial registration: For this prospective longitudinal pilot study we derived patients from a larger observational cohort study: CALIFORNIA-Trial, Dutch Trial Registry NTR4153

CATT voor de boomkwekerij - pilotproeven met sierheesterstek en vaste planten laten kansen voor de toekomst zien

In dit project hebben we het perspectief voor CATT-behandelingen (Controlled Atmosphere Temperature Treatment) voor boomkwekerijgewassen onderzocht. Deze methode combineert een CA-behandeling (gewijzigde luchtsamenstelling door aanpassing van CO2-en O2-condities) met een temperatuurbehandeling. Hiervoor wordt het plantmateriaal gedurende een bepaalde periode in een gasdichte cel bewaard. CATT-behandelingen zijn een duurzame vorm van plaagbestrijding omdat er geen chemische middelen aan te pas komen en omdat er geringe kans is op resistentieontwikkeling van de plaagorganismen. Bovendien kan deze methode zeer snel in praktijk worden geïmplementeerd omdat deze geen wettelijke toelating behoeft. Zo zijn in korte tijd CATT-behandelingen ontwikkeld voor het bestrijden van plagen in aardbei, die nu succesvol in praktijk worden toegepast. In dit project hebben we twee sierheesters in de stekfase (Buxus sempervirens en Ilex altaclerensis) en vier soorten vaste planten in de winterbewaring (Astilbe japonica, Geranium sanguineum, Phlox paniculata, Paeonia officinalis) behandeld en vergeleken met onbehandelde controles

Long-term research challenges in wind energy – a research agenda by the European Academy of Wind Energy

The European Academy of Wind Energy (eawe), representing universities and institutes with a significant wind energy programme in 14 countries, has discussed the long-term research challenges in wind energy. In contrast to research agendas addressing short- to medium-term research activities, this eawe document takes a longer-term perspective, addressing the scientific knowledge base that is required to develop wind energy beyond the applications of today and tomorrow. In other words, this long-term research agenda is driven by problems and curiosity, addressing basic research and fundamental knowledge in 11 research areas, ranging from physics and design to environmental and societal aspects. Because of the very nature of this initiative, this document does not intend to be permanent or complete. It shows the vision of the experts of the eawe, but other views may be possible. We sincerely hope that it will spur an even more intensive discussion worldwide within the wind energy community

Inherited susceptibility to bleomycin-induced chromatid breaks in cultured peripheral blood lymphocytes

Background: Susceptibility to bleomycin-induced chromatid breaks in cultured peripheral blood lymphocytes may reflect the way a person deals with carcinogenic challenges. This susceptibility (also referred to as mutagen sensitivity) has been found to be increased in patients with environmentally related cancers, including cancers of the head and neck, lung, and colon, and, in combination with carcinogenic exposure, this susceptibility can greatly influence cancer risk. The purpose of this study was to assess the heritability of mutagen sensitivity. Methods: Heritability was determined by use of a maximum likelihood method that employed the FISHER package of pedigree analysis. Bleomycin-induced breaks per cell values for 135 healthy volunteers without cancer were determined. These individuals were from 53 different pedigrees and included 25 monozygotic twin pairs (n = 50), 14 pairs of dizygotes (twin pairs and siblings, n = 28), and 14 families selected on the basis of a first-degree relative who was successfully treated for head and neck cancer and who had no sign of recurrence for at least 1 year. All data were analyzed simultaneously, and different models of familial resemblance were fitted to the data. All P values are two-sided. Results: Our results showed no evidence for the influence of a shared family environment on bleomycin-induced chromatid breaks. Genetic influences, however, were statistically significant (P = .036) and accounted for 75% of the total variance. Conclusions: The high heritability estimate of the susceptibility to bleomycin-induced chromatid breaks indicates a clear genetic basis. The findings of this study support the notion that a common genetic susceptibility to DNA damage - and thereby a susceptibility to cancer - may exist in the general population

O-Glycosylation of snails

The glycosylation abilities of snails deserve attention, because snail species serve as intermediate hosts in the developmental cycles of some human and cattle parasites. In analogy to many other host-pathogen relations, the glycosylation of snail proteins may likewise contribute to these host-parasite interactions. Here we present an overview on the O-glycan structures of 8 different snails (land and water snails, with or without shell): Arion lusitanicus, Achatina fulica, Biomphalaria glabrata, Cepaea hortensis, Clea helena, Helix pomatia, Limax maximus and Planorbarius corneus. The O-glycans were released from the purified snail proteins by β-elimination. Further analysis was carried out by liquid chromatography coupled to electrospray ionization mass spectrometry and – for the main structures – by gas chromatography/mass spectrometry. Snail O-glycans are built from the four monosaccharide constituents: N-acetylgalactosamine, galactose, mannose and fucose. An additional modification is a methylation of the hexoses. The common trisaccharide core structure was determined in Arion lusitanicus to be N-acetylgalactosamine linked to the protein elongated by two 4-O-methylated galactose residues. Further elongations by methylated and unmethylated galactose and mannose residues and/or fucose are present. The typical snail O-glycan structures are different to those so far described. Similar to snail N-glycan structures they display methylated hexose residues

Different approaches to research and innovation in physics education at college and university

In this article we report a Symposium organized by GTG-Physics Education Research at University (PERU) with different proposals that includes innovative educational approaches and research on problems of teaching-learning physics at university. In the second section, two research projects are described on teaching specific curriculum topics that present special difficulties for students. In the next section the third project on a work experience in the laboratory that takes into account the characteristics of scientific work, is presented. Finally, the fourth project presents a way to investigate the types of student reasoning. In the discussion, the importance of research projects that include not only conceptual understanding but also those areas such as laboratory work or "on-line physics courses" that involve practicing skills of scientific work, is highlighted.Publisher PD

Staat van de ambtelijke dienst 2015 De overheid in tijden van verandering

bookHervorming Sociale Regelgevin