Multilayer coating facility for the HEFT hard x-ray telescope

A planar magnetron sputtering facility has been established at the Danish Space Research Institute (DSRI) for the production coating of depth graded multilayers on the thermally slumped glass segments which form the basis for the hard X-ray telescope on the HEFT balloon project. The facility is capable of coating 20-45 mirrors segments in each run. The coatings are optimized W/Si coatings. The paper describes the facility, the results of the calibration and presents data for the X-ray testing of flight mirrors

Citizen Seismology in the Arctic

Landslides, earthquakes and other natural disasters are expected to increase in the Arctic, yet our ability to make informed decisions about safety is tightly limited by lack of data. As part of the Integrated Arctic Observation System (INTAROS) project, geophones were installed by residents in Greenland and by University of Bergen in Svalbard in 2018. The purpose of the installations was to explore challenges and benefits of community-based data collection for seismological monitoring in the Arctic region. Raspberry Shake units with one/three-component velocity sensors were selected for the deployment, due to their user-friendly configuration, easy installation, and well established digital platform and web services. The purpose of engaging community members in the use of geophone sensors was to monitor earthquakes, cryoseisms (events generated by ice mass), and landslides. We report our findings with respect to challenges regarding the installation and operation of the Raspberry Shake sensors at both locations. Connecting community-based recordings with permanent seismological networks improved both the detection capability and the data support for understanding seismic events in Greenland. In contrast, finding suitable locations for deployments in Longyearbyen turned out to be challenging, because most buildings are constructed on poles due to the permafrost and indoor space is expensive. Promoting citizen seismology in the Arctic could improve monitoring of seismic events in the Arctic while simultaneously raising community awareness of natural hazards.publishedVersio

Muons and emissivities of neutrinos in neutron star cores

In this work we consider the role of muons in various URCA processes relevant for neutrino emissions in the core region of neutron stars. The calculations are done for $\beta$--stable nuclear matter with and without muons. We find muons to appear at densities $\rho = 0.15$ fm$^{-3}$, slightly around the saturation density for nuclear matter $\rho_0 =0.16$ fm$^{-3}$. The direct URCA processes for nucleons are forbidden for densities below $\rho = 0.5$ fm$^{-3}$, however the modified URCA processes with muons $(n+N\rightarrow p+N +\mu +\overline{\nu}_{\mu}, p+N+\mu \rightarrow n+N+\nu_{\mu}$), where $N$ is a nucleon, result in neutrino emissivities comparable to those from $(n+N\rightarrow p+N +e +\overline{\nu}_e, p+N+e \rightarrow n+N+\nu_e$). This opens up for further possibilities to explain the rapid cooling of neutrons stars. Superconducting protons reduce however these emissivities at densities below $0.4$ fm$^{-3}$.Comment: 14 pages, Revtex style, 3 uuencoded figs include

Cl 1103.7-1245 at z=0.96: the highest redshift galaxy cluster in the EDisCS survey

We present new spectroscopic observations in a field containing the highest redshift cluster of the ESO Distant Cluster Survey (EDisCS). We measure galaxy redshifts and determine the velocity dispersions of the galaxy structures located in this field. Together with the main cluster Cl1103.7$-$1245 (z=0.9580; sigma_{clus} = 522 +/- 111 km/s) we find a secondary structure at z=0.9830, Cl1103.7-1245c. We then characterize the galaxy properties in both systems, and find that they contain very different galaxy populations. The cluster Cl1103.7-1245 hosts a mixture of passive elliptical galaxies and star-forming spirals and irregulars. In the secondary structure Cl1103.7-1245c all galaxies are lower-mass star-forming irregulars and peculiars. In addition, we compare the galaxy populations in the Cl1103.7-1245 z=0.9580 cluster with those in lower redshift EDisCS clusters with similar velocity dispersions. We find that the properties of the galaxies in Cl1103.7-1245 follow the evolutionary trends found at lower redshifts: the number of cluster members increases with time in line with the expected growth in cluster mass, and the fraction of passive early-type galaxies increases with time while star-forming late types become less dominant. Finally, we find that the mean stellar masses are similar in all clusters, suggesting that massive cluster galaxies were already present at z~1.Comment: A&A in pres

Multilayer coating facility for the HEFT hard x-ray telescope

A planar magnetron sputtering facility has been established at the Danish Space Research Institute (DSRI) for the production coating of depth graded multilayers on the thermally slumped glass segments which form the basis for the hard X-ray telescope on the HEFT balloon project. The facility is capable of coating 20-45 mirrors segments in each run. The coatings are optimized W/Si coatings. The paper describes the facility, the results of the calibration and presents data for the X-ray testing of flight mirrors

Forskning og udvikling i økologisk ægproduktion

Nærværende rapport er en beskrivelse og diskussion af forskningsprojekter gennemført under FØJO i årene 1996-1999. I korthed vidste forskningen følgende: Opdrætning og belægning Det har vist sig at konventionel opdræt giver en del problemer og der er anvendt en del kræfter på at belyse konsekvensen af forskellige opdrætningsmetoder, herunder lysintensitet, adgang til udeareal, opdræt på blivende sted eller flytning. Konklusionen fra disse undersøgelser er, at: Tidlig adgang til udearealet giver øget brug af udearealet senere, tendens til færre gulvæg og signifikant færre snavsede æg Opdrætning i hytte giver større kropsvægt, større ægvægt, færre gulvæg, færre snavsede æg og bedre fjerdragt end opdrætning under konventionelle forhold. Lav belægning i æglægningsperioden med 3.5 høner pr. m2 giver højere læggeprocent, bedre fodereffektivitet, tendens til færre gulvæg og signifikant færre snavsede æg samt bedre fjerdragt, dog kun hos de høner, der var opdrættet i stald Avl og selektion Avlsmaterialets kvalitet har været en vigtig del af forskningsarbejdet, dels fordi der kun er få avlsvirksomheder tilbage, der sælger afstamninger med en vis æglægningskapacitet, dels fordi disse afstamninger primært er fremavlet med sigte på burægsproduktion. Den konklusion, der kan drages af de genetiske studier er, at såfremt fjerpilningsadfærd inddrages i et passende selektionsprogram, vil et af de største velfærdsproblemer inden for ægproduktion blive løst. Parasitter Et problem, som møder den økologiske høne, er indvoldsorme. Mulighederne for at forebygge på dette område er i projektet blevet undersøgt i forskellige sammenhænge. Konklusionen er, at man må regne med, at indvoldorme altid vil være til stede i en vis udstrækning, når besætningen har adgang til udendørs arealer. Fuldstændig udryddelse er ikke mulig. I dag findes der kun konventionelle antiparasitære midler til behandling og kontrol af parasitære infektioner. Disse midler anses ikke for at være anvendelige, da tilbageholdelsestiderne er lange. På sigt bør man avlsmæssigt arbejde mod at etablere specielle racer til udendørsproduktion som er resistente mod parasitære og andre infektioner. Grovfoder Forsøg med tildeling af grovfoder har haft en positiv effekt på ægproduktion, forbrug af fuldfoder og der var en markant lavere dødelighed. Der kan iagttages mindre fjerpilning og en forbedring af fjerdragtens kvalitet, når der gives grovfoder. Endelig kunne der hvad angår tarmsundhed konstateres en øget kråseaktivitet og øget fermentering i blindtarmene samt lavere antal af coliforme bakterier, laktose negative bakterier og enterokokker. På temamødet på Forskningscenter Foulum, berettede flere landmænd om græsrodsprojekterne, og deres resultater og erfaringer er beskrevet i denne rapport. I sit afsnit vurderer Arne Bæk Jensen bl.a., at det økologiske opdræt og anvendelsen af kyllingemødre har været en succes idet: Kyllingerne har levet under forhold, som har givet en forøgelse af dyrevelfærden. Indeklimaet i opdrætsstalden har været godt som følge af et tørt gulv Energiforbruget er blevet reduceret Den tidlige prægning har haft sin virkning I æglægningsstalden sidder ca. 90 pct. af hønerne på siddepindene om natten efter ca. 14 dage Noget tyder på, at de høner, som ikke kommer på pindene om natten, også lægger deres æg på gulvet, hvor de overnatter. Hønerne på siddepindene har en bedre redesøgningsadfærd Ved indsætning ligger hønerne et pænt stykke over normen for væg

Hospital contacts for injuries and musculoskeletal diseases among seamen and fishermen: A population-based cohort study

<p>Abstract</p> <p>Background</p> <p>We studied musculoskeletal diseases (MSD) and injuries among fishermen and seamen with focus on low back disorders, carpal tunnel syndrome (CTS), rotator cuff syndrome and arthrosis.</p> <p>Methods</p> <p>Cohorts of all male Danish seamen (officers and non-officers) and fishermen employed 1994 and 1999 with at least six months employment history were linked to the Occupational Hospitalisation Register. We calculated standardised incidence ratios (SIR) for the two time periods, using rates for the entire Danish workforce as a reference.</p> <p>Results</p> <p>Among fishermen, we found high SIRs for knee arthrosis, thoraco-lumbar disc disorders, injuries and statistically significant SIRs above 200 were seen for both rotator cuff syndrome and CTS. The SIR was augmented for injuries and reduced for hip arthrosis between the two time periods. The SIRs for injuries and CTS were high for non-officers. A sub-analysis revealed that the highest risk for CTS was found among male non-officers working as deck crew, SIR 233 (95% CI: 166–317) based on 40 cases. Among officers, the SIRs for injuries and MSDs were low. The number of employed Danish fishermen declined with 25% 1994–1999 to 3470. Short-term employments were common. None of the SIRs increased with increasing length of employment.</p> <p>Conclusion</p> <p>Both fishermen and non-officers have high SIRs for injuries and fishermen also for MSD. Only the SIR for injuries among fishermen was augmented between 1994 and 1999. Our findings suggest an association between the incidence of rotator cuff syndrome and CTS and work within fishery. Long-term cumulative effects of employment were not shown for any of the disease outcomes. Other conditions may play a role.</p

Evolution of the Early-Type Galaxy Fraction in Clusters since z = 0.8

We study the morphological content of a large sample of high-redshift clusters to determine its dependence on cluster mass and redshift. Quantitative morphologies are based on bulge+disk decompositions of cluster and field galaxies on deep VLT/FORS2 images of 18 optically-selected clusters at 0.45 < z < 0.80 from the ESO Distant Cluster Survey (EDisCS). Morphological content is given by the early-type galaxy fraction f_et, and early-type galaxies are selected based on their bulge fraction and image smoothness. A set of 158 SDSS clusters is analyzed exactly as the EDisCS sample to provide a robust local comparison. Our main results are: (1) f_et values for the SDSS and EDisCS clusters exhibit no clear trend as a function of sigma. (2) Mid-z EDisCS clusters around sigma = 500 km/s have f_et ~= 0.5 whereas high-z EDisCS clusters have f_et ~= 0.4 (~25% increase over 2 Gyrs). (3) There is a marked difference in the morphological content of EDisCS and SDSS clusters. None of the EDisCS clusters have f_et greater than 0.6 whereas half of the SDSS clusters lie above this value. This difference is seen in clusters of all velocity dispersions. (4) There is a strong correlation between morphology and star formation in SDSS and EDisCS clusters. This correlation holds independent of sigma and z even though the fraction of [OII] emitters decreases from z~0.8 to z~0.06 in all environments. Our results pose an interesting challenge to structural transformation and star formation quenching processes that strongly depend on the global cluster environment and suggest that cluster membership may be of lesser importance than other variables in determining galaxy properties. (ABRIDGED)Comment: 22 pages, 10 figures, accepted for publication in A&

The impact of self-reported exposure to whole-body-vibrations on the risk of disability pension among men: a 15 year prospective study

<p>Abstract</p> <p>Background</p> <p>Whole-body-vibrations are often associated with adverse health effect but the long term effects are less known. This study investigates the association between occupational exposures to whole-body vibrations, and subsequent transition to disability pension.</p> <p>Methods</p> <p>A total of 4215 male employees were followed up for subsequent disability pension retirement. Exposure to whole-body-vibration was self-reported while new cases of disability pension were retrieved from a national register.</p> <p>Results</p> <p>The hazard ratio (HR) for disability pension retirement among men exposed to whole-body-vibrations was 1.61 (95% confidence interval (CI) 1.07-2.40) after adjustment for age, smoking habits, BMI, physical job demands and awkward work postures. In our model, with the available explanatory variables, 5.6% of the male disability pension cases were attributable to whole-body-vibrations.</p> <p>Conclusions</p> <p>Exposure to whole-body-vibrations predicts subsequent disability pension retirement. Continued reduction of whole-body-vibrations may reduce the number of new cases of disability pension.</p