Sleep-Disordered Breathing in Alcoholics

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66229/1/j.1530-0277.1999.tb04034.x.pd

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Best beschikbare methoden in levenscyclus analyses voor klimaatverandering, ozon, verzuring en eutrofiering. Achtergrond van specifieke categorieen

This report has been prepared by the SETAC Europe Scientific Task Group on Global And RegionaL Impact Categories (SETAC-Europe/STG-GARLIC) that is installed by the 2nd SETAC Europe working group on life cycle impact assessment (WIA-2). This document is background to a chapter written by the same authors under the title "Climate change, stratospheric ozone depletion, photo-oxidant formation, acidification and eutrophication" in Udo de Haes et al. (2002) . The chapter summarises the work of the STG-GARLIC and aims to give a state-of-the-art review of the best available practice(s) regarding category indicators and lists of concomitant characterisation factors for climate change, stratospheric ozone depletion, photo-oxidant formation, acidification, and aquatic and terrestrial eutrophication. Backgrounds on a selection of general issues relevant in relation to LCA and characterisation of impact in LCA are given in another background report from Potting and Klvpffer (2001)

Best beschikbare methoden in levenscyclus analyses voor klimaatverandering, ozon, verzuring en eutrofiering. Achtergrond van specifieke categorieen

Alleen digitaal verschenen<br>This report has been prepared by the SETAC Europe Scientific Task Group on Global And RegionaL Impact Categories (SETAC-Europe/STG-GARLIC) that is installed by the 2nd SETAC Europe working group on life cycle impact assessment (WIA-2). This document is background to a chapter written by the same authors under the title "Climate change, stratospheric ozone depletion, photo-oxidant formation, acidification and eutrophication" in Udo de Haes et al. (2002) . The chapter summarises the work of the STG-GARLIC and aims to give a state-of-the-art review of the best available practice(s) regarding category indicators and lists of concomitant characterisation factors for climate change, stratospheric ozone depletion, photo-oxidant formation, acidification, and aquatic and terrestrial eutrophication. Backgrounds on a selection of general issues relevant in relation to LCA and characterisation of impact in LCA are given in another background report from Potting and Klvpffer (2001) .RIV

Best available practice in life cycle assessment of climate change, stratospheric ozone depletion, photo-oxidant formation, acidification, and eutrophication-Backgrounds on specific impact categories

Alleen digitaal verschenen<br&gt

A validation of carbon fiber imaging couch top modeling in two radiation therapy treatment planning systems: Philips Pinnacle³ and BrainLAB iPlan RT Dose

<p>Abstract</p> <p>Background</p> <p>Carbon fiber (CF) is now the material of choice for radiation therapy couch tops. Initial designs included side metal bars for rigidity; however, with the advent of IGRT, involving on board imaging, new thicker CF couch tops without metal bars have been developed. The new design allows for excellent imaging at the expense of potentially unacceptable dose attenuation and perturbation.</p> <p>Objectives</p> <p>We set out to model the BrainLAB imaging couch top (ICT) in Philips Pinnacle³ treatment planning system (TPS), to validate the already modeled ICT in BrainLAB iPlan RT Dose treatment planning system and to compute the magnitude of the loss in skin sparing.</p> <p>Results</p> <p>Using CF density of 0.55 g/cm³ and foam density of 0.03 g/cm³, we demonstrated an excellent agreement between measured dose and Pinnacle³ TPS computed dose using 6 MV beam. The agreement was within 1% for all gantry angle measured except for 120^o, which was 1.8%. The measured and iPlan RT Dose TPS computed dose agreed to within 1% for all gantry angles and field sizes measured except for 100^o where the agreement was 1.4% for 10 cm × 10 cm field size. Predicted attenuation through the couch by iPlan RT Dose TPS (3.4% - 9.5%) and Pinnacle³ TPS (2% - 6.6%) were within the same magnitude and similar to previously reported in the literature. Pinnacle³ TPS estimated an 8% to 20% increase in skin dose with increase in field size. With the introduction of the CF couch top, it estimated an increase in skin dose by approximately 46 - 90%. The clinical impact of omitting the couch in treatment planning will be dependent on the beam arrangement, the percentage of the beams intersecting the couch and their angles of incidence.</p> <p>Conclusion</p> <p>We have successfully modeled the ICT in Pinnacle³ TPS and validated the modeled ICT in iPlan RT Dose. It is recommended that the ICT be included in treatment planning for all treatments that involve posteriors beams. There is a significant increase in skin dose that is dependent on the percentage of the beam passing through the couch and the angle of incidence.</p