Using SIMs to re-create cultural historical values in buildings from before 1945

In Sweden, approximately 25% of the energy use in buildings is attributed to buildings from before 1945. In this study, in-depth inventories were made in 94 buildings of cultural historical values (ornamentation, original materials and paint, etc.) and the interior status of the building (cracks, moisture damage, additional insulation, etc.). The inventories were used to investigate alternative and improved solutions for re-renovation to re-create e.g. architectural details and cultural historical values using novel materials. Two case studies are investigated where super insulation materials can be an alternative during renovation

Interior insulation using super insulation materials: saving energy and space

Interior insulation can be used in buildings where the exterior characteristics may not be altered due to cultural heritage protection. This is common for many buildings in Sweden from the period before 1941. Energy efficiency, thermal comfort and building performance are all affected by an interior insulation. Super insulation materials present novel opportunities to save both energy and space. The aim of this study is to investigate the benefits and drawbacks of using super insulation materials as interior insulation. A field study building was investigated for feasibility, which, together with interviews with professionals in the field of architecture, cultural heritage and building consultants, give a general overview. In conclusion, there are both benefits and drawbacks with interior insulation. Super insulation provides increased flexibility in terms of interior detailing and possibility to preserve characteristic elements. On building level interior super insulation could reduce the energy use by up to 20%. This gives energy savings of 0.5 TWh on national level and a reduction of 0.7% of the total CO2 emissions for heating the Swedish building stock. A drawback is that there are few examples and little experience from building with super insulation materials among both architects and other decision makers

Experiences from Interior Super Insulation of a Brick Wall from the 1800s

Many brick buildings in Sweden today face a large need for renovation measures to prolong their service life and make other uses possible. Conventional thermal insulation materials, such as fibre glass and EPS, demand a thick layer of insulation to reach the energy targets. Super insulation materials, such as vacuum insulation panels (VIP) and aerogel blankets (AB), are thermal insulation components with a 3-10 times higher thermal resistance than conventional insulation materials. In this study, the effect of interior insulation using super insulation materials is investigated, using experiences from a case study in a brick wall from the 1800s. Earlier research has shown that interior insulation decreases the drying-out capacity of an exterior wall and increases the risk for freeze-thaw damages in brick walls. The case study building is an industrial building from 1896 with 470 mm homogeneous brick masonry walls insulated with both aerogel insulation and with vacuum insulation panels. Six heat flux sensors were installed in the wall and used to evaluate the thermal resistance of the wall with and without insulation. The initial measurements showed that the rate of water flow in the bricks is approximately three times higher than that in modern bricks. The average calculated U-value was reduced by 70% for the AB and 81% for the VIP layers, while measurements at the three occasions gave a reduction of 72-83% for the AB and 72-84% for the VIP layers, i.e. in the same order of magnitude

Effect of quantum noise on Coulomb blockade in normal tunnel junctions at high voltages

We have investigated asymptotic behavior of normal tunnel junctions at voltages where even the best ohmic environments start to look like RC transmission lines. In the experiments, this is manifested by an exceedingly slow approach to the linear behavior above the Coulomb gap. As expected on the basis of the quantum theory taking into account interaction with the environmental modes, better fits are obtained using 1/sqrt{V}- than 1/V- dependence for the asymptote. These results agree with the horizon picture if the frequency-dependent phase velocity is employed instead of the speed of light in order to determine the extent of the surroundings seen by the junction.Comment: 9 pages, 4 figures, submitted to Phys. Rev.

The spectroscopic evolution of the symbiotic star AG Draconis. I.The O VI Raman, Balmer, and helium emission line variations during the outburst of 2006-2008

AG Dra is one of a small group of low metallicity S-type symbiotic binaries with K-type giants that undergoes occasional short-term outbursts of unknown origin. Our aim is to study the behavior of the white dwarf during an outburst using the optical Raman lines and other emission features in the red giant wind. The goal is to determine changes in the envelope and the wind of the gainer in this system during a major outburst event and to study the coupling between the UV and optical during a major outburst. Using medium and high resolution groundbased optical spectra and comparisons with archival $FUSE$ and $HST/STIS$ spectra, we study the evolution of the Raman O VI features and the Balmer, He I, and He II lines during the outburst from 2006 Sept. through 2007 May and include more recent observations (2009) to study the subsequent evolution of the source. The O VI Raman features disappeared completely at the peak of the major outburst and the subsequent variation differs substantially from that reported during the previous decade. The He I and He II lines, and the Balmer lines, vary in phase with the Raman features but there is a double-valuedness to the He I 6678, 7065 relative to the O VI Raman 6825\AA\ variations in the period between 2006-2008 that has not been previously reported. The variations in the Raman feature ratio through the outburst interval are consistent with the disappearance of the O VI FUV resonance wind lines from the white dwarf and of the surrounding O$^{+5}$ ionized region within the red giant wind provoked by the expansion and cooling of the white dwarf photosphere.Comment: 10 pages, 15 figs. A&A (in press, accepted for publication 23/11/2009

Interior super insulation in heritage buildings: Challenges and possibilities to conserve heritage values and increase energy performance

Super insulation materials (SIM) are insulation material with a very low thermal conductivity, even lower than stagnant air. The aim of the project has been to show how these materials can be used to save energy and space, as well as to contribute to preservation of exterior character defining elements while maintaining the temperature and humidity performance of the walls when renovating buildings built before 1945. The project was performed by researchers in the fields of building physics and building conservation. Brick buildings in Sweden have been in focus, as these buildings have one of the largest energy efficiency potentials in the entire building stock. Brick buildings often challenge engineers and architects by having contradicting demands on energy efficiency and cultural heritage values. Often, the fa\ue7ades of these buildings have valuable character defining elements that make them difficult to insulate. There are also problems with the building components, technical service life and insufficient thermal comfort indoors. Experts in architecture and building conservation have contributed with knowledge through interviews and practical work at study visits and by reviewing drawings and construction documents. Collaboration partners, linked to the reference group, contributed to the project with their knowledge in interviews, meetings and seminars. The project has led to an increased knowledge and understanding of the technical difficulties that exist when preserving character defining elements while imposing energy efficiency measures with super insulation materials in buildings. Advantages of super insulation materials are, for example, that they add little thickness to the walls and that the flexible materials, such as aerogel blankets, can contribute to preservation of character defining elements in heritage buildings. The disadvantage of using super insulation materials as interior insulation is, as for all insulation materials, that the lowered temperatures in the wall can lead to increased moisture levels and also that the drying out capacity of the wall can decrease. Due to the risks with interior insulation of walls, it is important to thoroughly investigate if the wall is suitable for interior insulation

The spectroscopic evolution of the symbiotic-like recurrent nova V407 Cygni during its 2010 outburst. I. The shock and its evolution

On 2010 Mar 10, V407 Cyg was discovered in outburst, eventually reaching V< 8 and detected by Fermi. Using medium and high resolution ground-based optical spectra, visual and Swift UV photometry, and Swift X-ray spectrophotometry, we describe the behavior of the high-velocity profile evolution for this nova during its first three months. The peak of the X-ray emission occurred at about day 40 with a broad maximum and decline after day 50. The main changes in the optical spectrum began at around that time. The He II 4686A line first appeared between days 7 and 14 and initially displayed a broad, symmetric profile that is characteristic of all species before day 60. Low-excitation lines remained comparatively narrow, with v(rad,max) of order 200-400 km/s. They were systematically more symmetric than lines such as [Ca V], [Fe VII], [Fe X], and He II, all of which showed a sequence of profile changes going from symmetric to a blue wing similar to that of the low ionization species but with a red wing extended to as high as 600 km/s . The Na I D doublet developed a broad component with similar velocity width to the other low-ionization species. The O VI Raman features were not detected. We interpret these variations as aspherical expansion of the ejecta within the Mira wind. The blue side is from the shock penetrating into the wind while the red wing is from the low-density periphery. The maximum radial velocities obey power laws, v(rad,max) t^{-n} with n ~ 1/3 for red wing and ~0.8 for the blue. (truncated)Comment: Accepted for publication, A&A (submitted: 9 Oct 2010; accepted: 1 Dec 2010) in press; based on data obtained with Swift, Nordic Optical Telescope, Ondrejov Observatory. Corrected typo, Fermi?LAT detection was at energies above 100 MeV (with thanks to C. C. Cheung

Heavy Elements and Cool Stars

We report on progress in the analysis of high-resolution near-IR spectra of alpha Orionis (M2 Iab) and other cool, luminous stars. Using synthetic spectrum techniques, we search for atomic absorption lines in the stellar spectra and evaluate the available line parameter data for use in our abundance analyses. Our study concentrates on the post iron-group elements copper through zirconium as a means of investigating the slow neutron-capture process of nucleosynthesis in massive stars and the mechanisms that transport recently processed material up into the photospheric region. We discuss problems with the atomic data and model atmospheres that need to be addressed before theoretically derived elemental abundances from pre-supernova nucleosynthesis calculations can be tested by comparison with abundances determined from observations of cool, massive stars

Safety of intravenous thrombolysis for acute ischemic stroke in patients receiving antiplatelet therapy at stroke onset

&lt;p&gt;&lt;b&gt;Background and Purpose:&lt;/b&gt; Antiplatelets (APs) may increase the risk of symptomatic intracerebral hemorrhage (ICH) following intravenous thrombolysis after ischemic stroke.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods:&lt;/b&gt; We assessed the safety of thrombolysis under APs in 11 865 patients compliant with the European license criteria and recorded between 2002 and 2007 in the Safe Implementation of Treatments in Stroke (SITS) International Stroke Thrombolysis Register (SITS-ISTR). Outcome measures of univariable and multivariable analyses included symptomatic ICH (SICH) per SITS Monitoring Study (SITS-MOST [deterioration in National Institutes of Health Stroke Scale &gt;= 4 plus ICH type 2 within 24 hours]), per European Cooperative Acute Stroke Study II (ECASS II [deterioration in National Institutes of Health Stroke Scale &gt;= 4 plus any ICH]), functional outcome at 3 months and mortality.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Results:&lt;/b&gt; A total of 3782 (31.9%) patients had received 1 or 2 AP drugs at baseline: 3016 (25.4%) acetylsalicylic acid (ASA), 243 (2.0%) clopidogrel, 175 (1.5%) ASA and dipyridamole, 151 (1.3%) ASA and clopidogrel, and 197 (1.7%) others. Patients receiving APs were 5 years older and had more risk factors than AP nave patients. Incidences of SICH per SITS-MOST (ECASS II respectively) were as follows: 1.1% (4.1%) AP naive, 2.5% (6.2%) any AP, 2.5% (5.9%) ASA, 1.7% (4.2%) clopidogrel, 2.3% (5.9%) ASA and dipyridamole, and 4.1% (13.4%) ASA and clopidogrel. In multivariable analyses, the combination of ASA and clopidogrel was associated with increased risk for SICH per ECASS II (odds ratio, 2.11; 95% CI, 1.29 to 3.45; P = 0.003). However, we found no significant increase in the risk for mortality or poor functional outcome, irrespective of the AP subgroup or SICH definition.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusion:&lt;/b&gt; The absolute excess of SICH of 1.4% (2.1%) in the pooled AP group is small compared with the benefit of thrombolysis seen in randomized trials. Although caution is warranted in patients receiving the combination of ASA and clopidogrel, AP treatment should not be considered a contraindication to thrombolysis.&lt;/p&gt