Investigating changes in mortality attributable to heat and cold in Stockholm, Sweden.

Projections of temperature-related mortality rely upon exposure-response relationships using recent data. Analyzing long historical data and trends may extend knowledge of past and present impacts that may provide additional insight and improve future scenarios. We collected daily mean temperatures and daily all-cause mortality for the period 1901-2013 for Stockholm County, Sweden, and calculated the total attributable fraction of mortality due to non-optimal temperatures and quantified the contribution of cold and heat. Total mortality attributable to non-optimal temperatures varied between periods and cold consistently had a larger impact on mortality than heat. Cold-related attributable fraction (AF) remained stable over time whereas heat-related AF decreased. AF on cold days remained stable over time, which may indicate that mortality during colder months may not decline as temperatures increase in the future. More research is needed to enhance estimates of burdens related to cold and heat in the future

Scaling of impact fragmentation near the critical point

We investigated two-dimensional brittle fragmentation with a flat impact experimentally, focusing on the low impact energy region near the fragmentation-critical point. We found that the universality class of fragmentation transition disagreed with that of percolation. However, the weighted mean mass of the fragments could be scaled using the pseudo-control parameter multiplicity. The data for highly fragmented samples included a cumulative fragment mass distribution that clearly obeyed a power-law. The exponent of this power-law was 0.5 and it was independent of sample size. The fragment mass distributions in this regime seemed to collapse into a unified scaling function using weighted mean fragment mass scaling. We also examined the behavior of higher order moments of the fragment mass distributions, and obtained multi-scaling exponents that agreed with those of the simple biased cascade model.Comment: 6 pages, 6 figure

Transition from damage to fragmentation in collision of solids

We investigate fracture and fragmentation of solids due to impact at low energies using a two-dimensional dynamical model of granular solids. Simulating collisions of two solid discs we show that, depending on the initial energy, the outcome of a collision process can be classified into two states: a damaged and a fragmented state with a sharp transition in between. We give numerical evidence that the transition point between the two states behaves as a critical point, and we discuss the possible mechanism of the transition.Comment: Revtex, 12 figures included. accepted by Phys. Rev.

Selection between indoor or outdoor DC yards

SUMMARY In an HVDC converter station, the area where the DC apparatus are installed is referred to as the DC yard. Most common until now, apparatus in the DC yard are installed directly outdoor. However, in some cases, a closed shelter (a hall) is erected with DC apparatus installed inside. This is an indoor DC yard. To select between the indoor or outdoor solutions for a DC yard, there are many factors that will need to be weighted in. · With the outdoor solution and with the DC pole voltage up to 600 kV, the operational experiences in the last two decades have been satisfactory, mainly thanks to the application of hydrophobic coatings and silicone rubber insulators. · The uneven-wetting problem on horizontally installed wall bushings has been solved successfully through the application of hydrophobic coatings and silicone rubber insulators. · Station post insulators of porcelain with and without hydrophobic coatings have been used for outdoor with satisfactory performance with pole voltage up to 600 kV. Station post insulators with silicone rubber sheds are available today. · With the pole voltage of 800 kV and in polluted areas, to fulfill the mechanical requirement, it is necessary to use shorter creepage distances on silicone rubber insulators and porcelain insulator with hydrophobic coatings than that on porcelain insulators if the outdoor solution is preferred. · For the future pole voltage of 1100 kV, increased difficulties will be encountered in realizing an outdoor solution. Indoor solution may be more attractive. · An indoor solution will to a great extent release the difficulties for coordinating the internal and external insulation for vertically installed apparatus especially for UHVDC applications. · Although pollutants will appear inside the DC yard building, the frequency and intensity of wetting are significantly reduced in comparison to outdoor. If the level of relative humidity is under control, wetting of pollution can be eliminated. With the short creepage distances needed, a significantly compacted design can be achieved. · The major cost of the indoor solution is the building. This cost can partly be compensated by the reduced cost of apparatus. An improved reliability is the most important aspect in choosing the indoor solution

Adaptive Control Based on Retrospective Cost Optimization

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83558/1/AIAA-46741-507.pd