14 research outputs found
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Upgraded Calibrations of the Thomson System at DIII-D
The DIII-D Thomson system measures electron density and temperature with eight pulsed ND:YAG lasers along three paths through the plasma vessel. The components of the Thomson system are absolutely calibrated so the measurements can be combined into a single profile from a normalized plasma radius ({rho}) of about 0.1 to the edge of the plasma. A monochromator calibration and opto-electronic calibration measure the detectors' absolute sensitivity to background and pulsed light. A Rayleigh scattering calibration and transmission calibrations measure the transmission of light to the detectors. The calibration systems are being upgraded to reduce the effect of systematic errors on the temperature and density measurements. The systematic errors can be checked by a comparison of overlapping channels and estimated from fits to the profiles. The contributions of the systematic uncertainties relative to the statistical uncertainties of the measurement are discussed through simulations and experimental data
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Preoperative risk assessment tools for morbidity after cardiac surgery: a systematic review
BACKGROUND: Postoperative morbidity places considerable burden on health and resources. Thus, strategies to identify, predict, and reduce postoperative morbidity are needed.
AIMS: To identify and explore existing preoperative risk assessment tools for morbidity after cardiac surgery.
METHODS: Electronic databases (including MEDLINE, CINAHL, and Embase) were searched to December 2020 for preoperative risk assessment models for morbidity after adult cardiac surgery. Models exploring one isolated postoperative morbidity and those in patients having heart transplantation or congenital surgery were excluded. Data extraction and quality assessments were undertaken by two authors.
RESULTS: From 2251 identified papers, 22 models were found. The majority (54.5%) were developed in the USA or Canada, defined morbidity outcome within the in-hospital period (90.9%), and focused on major morbidity. Considerable variation in morbidity definition was identified, with morbidity incidence between 4.3% and 52%. The majority (45.5%) defined morbidity and mortality separately but combined them to develop one model, while seven studies (33.3%) constructed a morbidity-specific model. Models contained between 5 and 50 variables. Commonly included variables were age, emergency surgery, left ventricular dysfunction, and reoperation/previous cardiac surgery, although definition differences across studies were observed. All models demonstrated at least reasonable discriminatory power [area under the receiver operating curve (0.61-0.82)].
CONCLUSION: Despite the methodological heterogeneity across models, all demonstrated at least reasonable discriminatory power and could be implemented depending on local preferences. Future strategies to identify, predict, and reduce morbidity after cardiac surgery should consider the ageing population and those with minor and/or multiple complex morbidities
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New Thomson scattering Laser Control for DIII-D
A Laser Control system has been built for the DIII-D Scattering Diagnostic. This new system has provided the capability to place the laser probe pulses with one microsecond timing precision throughout the DIII-D shot. The new system fires the eight lasers with a programmable sequence which repeats ever 50 ms. If one wants to probe the plasma at a higher rate to study a fast paced event, the new control circuit can fire all charged lasers in rapid succession (BURST MODE). This burst rate is programmable. The new Laser Control system successfully replaced the previous control scheme which consisted of three VME Motorola 68030 computers (one host under UNIX VME V/68 and two interrupt driven targets under VME Exec. The old system was not successful due to the many VME interrupts needed to service the lasers. The new hardware approach is much more reliable. The old system still controls data acquisition and as a monitoring system since it does not have the burden of controlling the lasers. A brief description of the Thomson Scattering diagnostic will be presented with emphasis in the new upgraded laser firing control system and data acquisition timing control