Optimering af Hastighedsprofilet ved opgradering af Jernbaner

Gennem bl. a. Togfonden DK er der bevilget penge til en lang række jernbaneopgraderinger over hele landet. Der ligger derfor et stort projekteringsarbejde foran sektoren, hvilket bl.a. øger behovet for optimering af arbejdsprocesserne. Når sporets horisontale geometri, som grundlæggende består af kurver og rette linjestykker, forberedes til hastighedsopgradering, er det billigste tiltag at øge kurvernes overhøjde. Dette skal dog ske under hensyntagen til de krav og regler, Banedanmark har fastsat, og som sikrer et minimum af slid af infrastrukturen samt en sikker og komfortabel rejse for passagerne. I dag er der et stort manuelt arbejde forbundet med at vurdere muligheden for øge kurvernes overhøjde for at opnå en højere hastighed. Opgaven kompliceres yderligere af, at kurver, der deler en overgangskurve, påvirker hinanden indbyrdes – overhøjden, der vælges i den første kurve, har betydning for, hvilken overhøjde der kan vælges i den næste kurve og så fremdeles. Ydermere gælder der forskellige krav, alt efter om der projekteres efter ønskelige, normal- eller undtagelsesbestemmelser, ligesom perroner og sporskifter pålægger andre begrænsninger. Det er derfor vanskeligt og tidskrævende at finde det optimale hastighedsprofil manuelt. Denne artikel præsenterer en ny optimeringsmodel, som giver en løsning langt hurtigere og med garanti for optimalitet ud fra de givne forudsætninger. Modellen testes på en given strækning hvor kurveradier, kurvelængder, længden af overgangskurver og stationeringer benyttes som input. Ligeledes indikeres det på forhånd, i hvilke kurver der findes sporskifter og perroner, samt hvilke kurver, der ønskes projekteret efter hhv. ønskelige, normal- og undtagelsesbestemmelser. De krav og normer, der skal efterleves, indsættes som begrænsninger til modellen, således at de i løsningen vil være overholdt. Modellen optimerer overhøjder efter at finde den højest mulige hastighed i kurverne, således at hastighedsprofilet på strækningen bliver optimalt. Ud fra resultaterne fra modellen kan de kurver, der er begrænsende for hastigheden, hurtigt identificeres. Der kan herefter tages stilling til, om der for at opnå højere hastighed i disse kurver skal tillades undtagelsesbestemmelser, om overgangskurven skal forlænges eller om der skal foretages en kurveudretning. I forhold til en manuel proces kan der derfor identificeres en række forskellige scenarier for, hvordan en given banestrækning kan hastighedsopgraderes, således at beslutningsgrundlaget i sidste ende kan forbedres

Greener homes: Factors underpinning Europeans' intention to live in multi-storey wooden buildings

Climate policies aimed at curbing greenhouse gas emissions embodied in the built environment support the wider implementation of multi-storey wooden buildings. A body of research on public perceptions toward wood as a structural building material is emerging, but close examination of behavioral factors underpinning prospective dwelling is scarce. We used contextualized constructs from the theory of planned behavior to quantify and compare the roles of attitudes, subjective norms, and perceived behavioral control on intentions to dwell in multi-storey wooden buildings. Structural equation models were fitted to survey data from seven European countries (Austria, Denmark, Germany, Finland, Norway, Sweden, United Kingdom; n = 7056). We found that attitudes consistently explain intention to dwell in multi-storey wooden buildings. We also found a varied pattern of relationships between factors underpinning intention across countries. An implication of our results is that national-level policies aimed at promoting social acceptability of dwelling in multi-storey wooden buildings should universally address attitudes toward such novel buildings. But in some countries policies might in addition be tailored to emphasize citizens' subjective norms or perceived behavioral controls

Consolidated bioprocessing of starchy substrates into ethanol by industrial Saccharomyces cerevisiae strains secreting fungal amylases

The development of a yeast strain that converts raw starch to ethanol in one step (called Consolidated Bioprocessing, CBP) could significantly reduce the commercial costs of starch-based bioethanol. An efficient amylolytic Saccharomyces cerevisiae strain suitable for industrial bioethanol production was developed in this study. Codon-optimized variants of the Thermomyces lanuginosus glucoamylase (TLG1) and Saccharomycopsis fibuligera -amylase (SFA1) genes were -integrated into two S. cerevisiae yeast with promising industrial traits, i.e., strains M2n and MEL2. The recombinant M2n[TLG1-SFA1] and MEL2[TLG1-SFA1] yeast displayed high enzyme activities on soluble and raw starch (up to 8118 and 4461nkat/g dry cell weight, respectively) and produced about 64g/L ethanol from 200g/L raw corn starch in a bioreactor, corresponding to 55% of the theoretical maximum ethanol yield (g of ethanol/g of available glucose equivalent). Their starch-to-ethanol conversion efficiencies were even higher on natural sorghum and triticale substrates (62 and 73% of the theoretical yield, respectively). This is the first report of direct ethanol production from natural starchy substrates (without any pre-treatment or commercial enzyme addition) using industrial yeast strains co-secreting both a glucoamylase and -amylase

Draft whole-genome sequence of <em>Bacillus sonorensis </em>strain L12, a source of nonribosomal lipopeptides

The Bacillus sonorensis L12 draft genome sequence is approximately 4,647,754 bp in size with a G+C content of 45.2%. Over 86% of the genome contains protein-encoding genes, including several gene clusters for de novo biosynthesis of the nonribosomal lipopeptides iturin, bacitracin, and fengycin, which could mean that the strain exhibits antifungal effects

What do Danish children eat, and does the diet meet the recommendations?:Baseline data from the OPUS School Meal Study

A child's diet is an important determinant for later health, growth and development. In Denmark, most children in primary school bring their own packed lunch from home and attend an after-school care institution. The aim of the present study was to evaluate the food, energy and nutrient intake of Danish school children in relation to dietary guidelines and nutrient recommendations, and to assess the food intake during and outside school hours. In total, 834 children from nine public schools located in the eastern part of Denmark were included in this cross-sectional study and 798 children (95·7 %) completed the dietary assessment sufficiently (August–November 2011). The whole diet was recorded during seven consecutive days using the Web-based Dietary Assessment Software for Children (WebDASC). Compared with the food-based dietary guidelines and nutrient recommendations, 85 % of the children consumed excess amounts of red meat, 89 % consumed too much saturated fat, and 56 % consumed too much added sugar. Additionally 35 or 91 % of the children (depending on age group) consumed insufficient amounts of fruits and vegetables, 85 % consumed insufficient amounts of fish, 86 % consumed insufficient amounts of dietary fibre, 60 or 84 % had an insufficient Fe intake (depending on age group), and 96 % had an insufficient vitamin D intake. The study also showed that there is a higher intake of fruits and bread during school hours than outside school hours; this is not the case with, for example, fish and vegetables, and future studies should investigate strategies to increase fish and vegetable intake during school hours

Preprogrammed capillarity to passively control system-level sequential and parallel microfluidic flows

In microfluidics, capillarity-driven solution flow is often beneficial, owing to its inherently spontaneous motion. However, it is commonly perceived that, in an integrated microfluidic system, the passive capillarity control alone can hardly achieve well-controlled sequential and parallel flow of multiple solutions. Despite this common notion, we hereby demonstrate system-level sequential and parallel microfluidic flow processing by fully passive capillarity-driven control. After manual loading of solutions with a pipette, a network of microfluidic channels passively regulates the flow timing of the multiple solution menisci in a sequential and synchronous manner. Also, use of auxiliary channels and preprogramming of inlet-well meniscus pressure and channel fluidic conductance allow for controlling the flow direction of multiple solutions in our microfluidic system. With those components orchestrated in a single device chip, we show preprogrammed flow control of 10 solutions. The demonstrated system-level flow control proves capillarity as a useful means even for sophisticated microfluidic processing without any actively controlled valves and pumps.close5

The Cosmic Telescope that Lenses the Sunburst Arc, PSZ1 G311.65-18.48: Strong Gravitational Lensing model and Source Plane Analysis

We present a strong lensing analysis of the cluster PSZ1 G311.65-18.48, based on Hubble Space Telescope imaging, archival VLT/MUSE spectroscopy, and Chandra X-ray data. This cool-core cluster (z=0.443) lenses the brightest lensed galaxy known, dubbed the "Sunburst Arc" (z=2.3703), a Lyman continuum (LyC) emitting galaxy multiply-imaged 12 times. We identify in this field 14 additional strongly-lensed galaxies to constrain a strong lens model, and report secure spectroscopic redshifts of four. We measure a projected cluster core mass of M(<250 kpc)=2.93+0.01/-0.02x10^14M_sun. The two least-magnified but complete images of the Sunburst Arc's source galaxy are magnified by ~13x, while the LyC clump is magnified by ~4-80x. We present time delay predictions and conclusive evidence that a discrepant clump in the Sunburst Arc, previously claimed to be a transient, is not variable, thus strengthening the hypothesis that it results from an exceptionally high magnification. A source plane reconstruction and analysis of the Sunburst Arc finds its physical size to be 1x2 kpc, and that it is resolved in three distinct directions in the source plane, 0, 40, and 75 degrees (east of North). We place an upper limit of r <~ 50 pc on the source plane size of unresolved clumps, and r<~ 32 pc for the LyC clump. Finally, we report that the Sunburst Arc is likely in a system of two or more galaxies separated by <~6 kpc in projection. Their interaction may drive star formation and could play a role in the mechanism responsible for the leaking LyC radiation.Comment: 31 pages, 14 figures, 4 tables. Submitted to Ap