High prevalence of the 999del5 mutation in icelandic breast and ovarian cancer patients

Studies on Icelandic breast cancer families have shown that most of them segregate a 999del5 BRCA2 mutation. Here, we report the frequency of the 999del5 BRCA2 mutation in an Icelandic control population and four different groups of cancer patients diagnosed with (a) breast cancer; (b) ovarian cancer; (c) prostate cancer (patients younger than 65 years); and (d) other cancer types. The proportions of individuals carrying the mutation were 0.4% in the control population and in the patient groups 8.5%, 7.9%, 2.7%, and 1.0%, respectively. Our results indicate that BRCA2 confers a very high risk of breast cancer and is responsible for a substantial fraction of breast and ovarian cancer in Iceland, but only a small proportion of other cancers.     

The Svartsengi reservoir in Iceland

The Svartsengi geothermal reservoir in Iceland is described and its production history presented. Lumped-parameter models for confined and unconfined reservoirs are derived, and a conceptual model of the reservoir suggested. Using depletion analysis, the dominant production mechanism is identified as drainage of an unconfined reservoir.     

Deposition of paraffin wax from kerosene in cooled heat exchanger tubes

Studies of the deposition of wax from wax/kerosene mixtures onto cooled simulated heat transfer tubes has demonstrated that, following an initial deposition taking a relatively short period of time, the heat transfer resistance fluctuates with time. Theoretical estimates of temperature distribution in the experimental flowing wax/kerosene system suggest that the cloud point temperature of the mixture falls within the laminar boundary layer. Since the cloud point is considered the temperature at which particles of wax appear, the conditions within the boundary layer will influence deposition. Increased flowrate and temperature decrease the number of particles able to deposit while the number is increased by greater wax concentration in the bulk solution.     

Scaling of the discrete-time algebraic Riccati equation to enhancestability of the Schur solution method

A simple scaling procedure for discrete-time Riccati equations is introduced. This procedure eliminates instabilities which can be associated with the linear equation solution step of the generalized Schur method without changing the condition of the underlying problem. A computable bound for the relative error of the solution of the Riccati equation is also derived     

Age differences in visual evoked potential estimates on interhemishperic transfer.

Twenty-six younger (ages 18–36 years) and 19 older (ages 60–88 years) healthy right-handed men and women were tested for interhemispheric transfer by using visual evoked potentials lo laterally presented checkerboards. Interhemispheric transfer time (IHTT) was estimated by subtracting latencies for both P100 and N160 peaks of the waveform contralateral to the stimulus from the waveform ipsilateral to the stimulus for homologous sites. The quality of interhemispheric transfer was estimated by comparing peak-to-peak amplitudes for homologous sites. IHTT did not change across age, but there was a suppression of the waveform over the indirectly stimulated hemisphere in the older participants. The significance of this finding for age-related changes in functions mediated by the corpus callosum is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Display of Density Volumes

The advent of inexpensive, high-speed processing and storage has fueled interest in new ways to process and display 3D images. This new discipline of 3D imaging promises to produce a wealth of exciting applications in many fields. For three years, engineers at Linkoping University have experimented with algorithms and methods to display 3D images obtained from a variety of sources, including computer-aided tomography, transmission electron microscopy, and laser microscopy. This article reviews the applicability of different display methods for different types of volumes, the advantages and disadvantages of different techniques, and the results of experiments when image processing techniques were applied before the images were displayed.     

Online Fouling Detection of Domestic Hot Water Heat Exchangers

Due to hardness of cold water supply in many countries, there is a risk of fouling in domestic hot water (DHW) counterflow plate heat exchangers. The scaling will result in increased resistance to heat transfer, which has negative effects on the economics of the district heating network. A common approach is to clean or change the heat exchanger periodically, which can be expensive if only limited fouling has occurred (unnecessary) or if a higher than expected scaling layer has formed (inefficiency). A better approach is to monitor the state of the heat exchangers and clean them when actually required. This would result in more energy-efficient operation and provide an optimum schedule for heat exchanger cleaning. This can be simple if the heat exchangers are operating under steady-state conditions; however, if large variations in the inlets are experienced, as is the case with the mass flows in DHW heat exchangers, it quickly becomes impossible with standard methods. In this paper it is proposed to monitor the state of the heat exchanger online by using measurements that are easily obtainable under normal operation and applying fast mathematical models to estimate the overall heat transfer coefficient of the heat exchanger. The results show that the methods proposed can be used to detect fouling in DHW heat exchangers.     

Morphology of TiN thin films grown on SiO2 by reactive high power impulse magnetron sputtering

Thin TiN films were grown on SiO₂ by reactive high power impulse magnetron sputtering (HiPIMS) at a range of temperatures from 45 to 600 °C. The film properties were compared to films grown by conventional dc magnetron sputtering (dcMS) at similar conditions. Structural characterization was carried out using X-ray diffraction and reflection methods. The HiPIMS process produces denser films at lower growth temperature than does dcMS. Furthermore, the surface is much smoother for films grown by the HiPIMS process. The [200] grain size increases monotonically with increased growth temperature, whereas the size of the [111] oriented grains decreases to a minimum for a growth temperature of 400 °C after which it starts to increase with growth temperature. The [200] crystallites are smaller than the [111] crystallites for all growth temperatures. The grain sizes of both orientations are smaller in HiPIMS grown films than in dcMS grown films.     

Method for achieving hydraulic balance in typical Chinese building heating systems by managing differential pressure and flow

Hydraulic unbalance is a common problem in Chinese district heating (DH) systems. Hydraulic unbalance has resulted in poor flow distribution among heating branches and overheating of apartments. Studies show that nearly 30% of the total heat supply is being wasted in Chinese DH systems due to a lack of pressure and flow control. This study investigated using pre-set radiator valves combined with differential pressure (DP) controllers to achieve hydraulic balance in building distribution systems, and consequently save energy and reduce the emissions. We considered a multi-storey building modelled in the IDA-ICE software, along with a self-developed mathematical hydraulic model to simulate its heat performance and hydraulic performance with various control scenarios. In contrast to the situation with no pressure or flow control, this solution achieves the required flow distribution and close-to-design room temperatures, as well as 16% heat savings, 74% pump electricity savings, and proper cooling of supply water. The energy consumption savings would therefore have positive environmental impacts, and be reflected in seasonal reductions of 2.1 kg/m² CO₂, 0.02 kg/m² SO₂, and 0.01 kg/m² NO_x for 3rd step energy efficiency buildings in Beijing.