| 781. |
- Strömberg, Ulf, et al.
(författare)
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Cutaneous malignant melanoma show geographic and socioeconomic disparities in stage at diagnosis and excess mortality.
- 2016
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Ingår i: Acta oncologica (Stockholm, Sweden). - 1651-226X. ; 55:8, s. 993-1000
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Tidskriftsartikel (refereegranskat)abstract
- Background Preventive measures are needed to counteract the increasing burden of cutaneous malignant melanoma (CMM). As a basis for rational melanoma prevention, we investigated geographic differences and impact from socioeconomic factors related to incidence, clinical stage at diagnosis and outcome. Material and methods All patients with primary invasive CMM diagnosed in 2004-2013 in the southern and the western Swedish health care regions with a population of 2.9 million adults were eligible for the study. Population-based data were obtained from the national Cancer Register and the national Melanoma Quality Register. Geographic and socioeconomic differences in incidence per stage at diagnosis were mapped and correlated to excess mortality. Results Disease mapping based on 9743 cases in 99 municipalities and 20 metropolitan districts showed marked, regional disparities in stage-specific incidence of CMM. The incidence of stage I-II tumors was higher in the western health care region, whereas the incidence of stage III-IV CMMs was higher in the southern region. The divergent incidence patterns per stage at diagnosis were consistent across population strata based on educational level. The geographic disparities in CMM stage influenced relative survival with an excess five-year mortality ratio in the southern region versus the western region of 1.49 (95% confidence interval 1.22-1.82). The excess mortality ratio for patients with low versus high educational level was 1.81 (1.37-2.40). Conclusion Residential region and educational level influenced CMM stage and, thereby, excess mortality. These observations suggest that geographic as well as socioeconomic data should be considered in prevention of CMM.
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| 782. |
- Sturesson, Peter, 1981-, et al.
(författare)
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Effect of Resistive and Plasma Heating on the Specific Impulse of a Ceramic Cold Gas Thruster
- 2019
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Ingår i: Journal of microelectromechanical systems. - 1057-7157 .- 1941-0158. ; 28:2, s. 235-244
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Tidskriftsartikel (refereegranskat)abstract
- The research and development of small satellites has continued to expand over the last decades. However, the propulsion systems with adequate performance have persisted to be a great challenge. In this paper, the effects of three different heaters on the specific impulse and overall thrust efficiency of a cold gas microthruster are presented. They consisted of a conventional, printed resistive thick-film element, a freely suspended wire, and a stripline split-ring resonator microplasma source, and were integrated in a single device made from the high-temperature co-fired ceramics. The devices were evaluated in two setups, where the first measured thrust and the other measured shock cell geometry. In addition, the resistive elements were evaluated as gas temperature sensors. The microplasma source was found to provide the greatest improvement in both specific impulse and thrust efficiency, increasing the former from an un-heated level of 44–56 s when heating with a power of 1.1 W. This corresponded to a thrust efficiency of 55%, which could be compared with the results from the wire and printed heaters which were 51s and 18%, and 45s and 14%, respectively. The combined results also showed that imaging the shock cells of a plasma heated thruster was a simple and effective way to determine its performance, when compared to the traditional thrust balance method.
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| 783. |
- Sturesson, Peter, 1981-, et al.
(författare)
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Fabrication of Suspended All-Metal Sensor Elements in Ceramic Laminates
- 2016
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Ingår i: Proc. of Micronano System Workshop 2016, Lund, Sweden, May 17-18, 2016.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- To target a wide range of high-temperature applications [1-4], the Ångström Space Technology Centre has added High-Temperature Co-fired Ceramics, HTTC, technology to its repertoire. Usually, this technology follows a processing scheme where thin sheets of green-body ceramics are metallized through screen printing and structured by embossing, punching or milling, before they are laminated and sintered to form components. A limitation with this, is the difficulty of realizing freely suspended metal structures, which is a disadvantage in, e.g., the fabrication of calorimetric sensors or electric field probes. In this work, the embedding of platinum wires in HTCC is explored experimentally, and demonstrated for use in pressure and plasma I-V sensing.
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| 784. |
- Stålhandske, Christina, et al.
(författare)
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Fluid jet polishing of planar flat glass surfaces and within holes
- 2014
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Ingår i: European Journal of Glass Science and Technology. Part A: Glass Technology. - : Society of Glass Technology. - 1753-3546 .- 1753-3554. ; 55:2, s. 49-54
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Tidskriftsartikel (refereegranskat)abstract
- Planar ground float glass surfaces and the surfaces within holes are polished using fluid jet polishing (FJP) in order to improve their visual appearance or material strength. The large flexibility of FJP makes it suitable for polishing holes and other complex geometries. The influence of polishing speed, incident angle, distance, pressure, abrasive concentration, and nozzle diameter are investigated. Al2O3 is the abrasive used. The surface quality is evaluated visually and also measured with an optical profiler. The mechanical strength of the polished holes are evaluated with an MTS testing machine. Planar surfaces, and the surfaces of drilled and water cut holes are greatly improved by polishing. For a planar surface the lowest root mean square surface slope, Sdq, value achieved is 0·5 deg using 50% abrasive and 1000 mesh grains. The failure load of the glass with drilled holes increased 20% with FJP
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| 785. |
- Stålhandske, Christina, et al.
(författare)
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Polishing glass with fluid jet technology
- 2012
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Ingår i: Challenging Glass 3: Conference on Architectural and Structural Applications of Glass, CGC 2012. ; , s. 579-586
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Konferensbidrag (refereegranskat)abstract
- A fluid jet with 50% by weight of aluminum oxide is used to polish float glass. Both water cut edges and holes as well as drilled holes are polished. Using a pressure of 3.5 MPa, a 1.26 mm nozzle and 64 passes of the jet over the surface a bright appearance is achieved. The polishing result is evaluated both with the naked eye and an optical profiler. During mechanical testing of untreated holes it was found that a drilled hole can withstand 20% higher forces than a water cut hole before failure. The condition of the edge where the tensile stresses appear is very important and future work includes polishing this edge. © 2012 The authors and IOS Press. All rights reserved.
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| 786. |
- Sundqvist, Elin, et al.
(författare)
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Short-term effects of thinning, clear-cutting and stump harvesting on methane exchange in a boreal forest
- 2014
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 11:21, s. 6095-6105
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Tidskriftsartikel (refereegranskat)abstract
- Forest management practices can alter soil conditions, affecting the consumption and production processes that control soil methane (CH4) exchange. We studied the short-term effects of thinning, clear-cutting and stump harvesting on the CH4 exchange between soil and atmosphere at a boreal forest site in central Sweden, using an undisturbed plot as the control. Chambers in combination with a high-precision laser gas analyser were used for continuous measurements. Both the undisturbed plot and the thinned plot were net sinks of CH4, whereas the clear-cut plot and the stump harvested plot were net CH4 sources. The CH4 uptake at the thinned plot was reduced in comparison to the undisturbed plot. The shift from sink to source at the clear-cut and stump harvested plots was probably due to a rise in the water table and an increase in soil moisture, leading to lower gas diffusivity and more reduced conditions, which favour CH4 production by archea. Reduced evapotranspiration after harvesting leads to wetter soils, decreased CH4 consumption and increased CH4 production, and should be accounted for in the CH4 budget of managed forests.
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| 787. |
- Sundqvist, Elin, et al.
(författare)
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Upscaling of methane exchange in a boreal forest using soil chamber measurements and high-resolution LiDAR elevation data
- 2015
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Ingår i: Agricultural and Forest Meteorology. - : Elsevier BV. - 1873-2240 .- 0168-1923. ; 214, s. 393-401
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Tidskriftsartikel (refereegranskat)abstract
- Forest soils are generally considered to be net sinks of methane (CH4), but CH4 fluxes vary spatially depending on soil conditions. Measuring CH4 exchange with chambers, which are commonly used for this purpose, might not result in representative fluxes at site scale. Appropriate methods for upscaling CH4 fluxes from point measurements to site scale are therefore needed. At the boreal forest research site, Norunda, chamber measurements of soils and vegetation indicate that the site is a net sink of CH4, while tower gradient measurements indicate that the site is a net source of CH4. We investigated the discrepancy between chamber and tower gradient measurements by upscaling soil CH4 exchange to a 100 ha area based on an empirical model derived from chamber measurements of CH4 exchange and measurements of soil moisture, soil temperature and water table depth. A digital elevation model (DEM) derived from high-resolution airborne Light Detection and Ranging (LiDAR) data was used to generate gridded water table depth and soil moisture data of the study area as input data for the upscaling. Despite the simplistic approach, modeled fluxes were significantly correlated to four out of five chambers with R>0.68. The upscaling resulted in a net soil sink of CH4 of -10 mu mol m(-2) h(-1), averaged over the entire study area and time period June-September, 2010). Our findings suggest that additional contributions from CH4 soil sources outside the upscaling study area and possibly CH4 emissions from vegetation could explain the net emissions measured by tower gradient measurements. (C) 2015 Elsevier B.V. All rights reserved.
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| 788. |
- Suyatin, Dmitry, et al.
(författare)
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Strong Schottky barrier reduction at Au-catalyst/GaAs-nanowire interfaces by electric dipole formation and Fermi-level unpinning
- 2014
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Ingår i: Nature Communications. - London : Springer Science and Business Media LLC. - 2041-1723. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Nanoscale contacts between metals and semiconductors are critical for further downscaling of electronic and optoelectronic devices. However, realizing nanocontacts poses significant challenges since conventional approaches to achieve ohmic contacts through Schottky barrier suppression are often inadequate. Here we report the realization and characterization of low n-type Schottky barriers (~0.35 eV) formed at epitaxial contacts between Au-In alloy catalytic particles and GaAs-nanowires. In comparison to previous studies, our detailed characterization, employing selective electrical contacts defined by high-precision electron beam lithography, reveals the barrier to occur directly and solely at the abrupt interface between the catalyst and nanowire. We attribute this lowest-to-date-reported Schottky barrier to a reduced density of pinning states (~1017 m−2) and the formation of an electric dipole layer at the epitaxial contacts. The insight into the physical mechanisms behind the observed low-energy Schottky barrier may guide future efforts to engineer abrupt nanoscale electrical contacts with tailored electrical properties.
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| 789. |
- Svendsen, Kristoffer, et al.
(författare)
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Optimization of soft X-ray phase-contrast tomography using a laser wakefield accelerator
- 2018
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Ingår i: Optics Express. - 1094-4087. ; 26:26, s. 33930-33941
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Tidskriftsartikel (refereegranskat)abstract
- X-ray phase-contrast imaging allows for non-invasive analysis in low-absorbing materials, such as soft tissue. Its application in medical or materials science has yet to be realized on a wider scale due to the requirements on the X-ray source, demanding high flux and small source size. Laser wakefield accelerators generate betatron X-rays fulfilling these criteria and can be suitable sources for phase-contrast imaging. In this work, we present the first phase-contrast images obtained by using ionization injection-based laser wakefield acceleration, which results in a higher photon yield and smoother X-ray beam profile compared to self-injection. A peak photon yield of 1.9 × 1011 ph/sr and a source size of 3 μm were estimated. Furthermore, the current laser parameters produce an X-ray spectrum mainly in the soft X-ray range, in which laser-plasma based phase-contrast imaging had yet to be studied. The phase-contrast images of a Chrysopa lacewing resolve features on the order of 4 μm. These images are further used for a tomographic reconstruction and a volume rendering, showing details on the order of tens of μm.
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| 790. |
- Svenningsson, Josef, 1976, et al.
(författare)
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Efficient Monadic Streams
- 2015
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Ingår i: Trends in Functional Programming.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Functional stream representations allow for a high-level, compositional way of programming digital signal processing algorithms. However, some algorithms, such as filters, cannot be efficiently implemented using purely functional techniques, due to excessive copying of data. We present a monadic representation of streams which introduces the ability to use mutation for efficiency when implementing algorithms. Still, our representation enjoys many of the benefits of purely functional streams, such as a functional API and fusion. Our representation enables further optimizations: we show how to remove duplicate loop variables, and how to keep buffers entirely in references. Our measurements show that the new monadic representation consistently outperforms the functional representation by at least a factor of four when evaluated in the context of the Feldspar embedded DSL.
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