2 research outputs found
HVAC modifications and computerized energy analysis for the Operations Support Building at the Mars Deep Space Station at Goldstone
The key heating, ventilation, and air-conditioning (HVAC) modifications implemented at the Mars Deep Space Station's Operation Support Building at Jet Propulsion Laboratories (JPL) in order to reduce energy consumption and decrease operating costs are described. An energy analysis comparison between the computer simulated model for the building and the actual meter data was presented. The measurement performance data showed that the cumulative energy savings was about 21% for the period 1979 to 1981. The deviation from simulated data to measurement performance data was only about 3%
Prognostic Value of Right Ventricular Dysfunction and Tricuspid Regurgitation in Patients with Severe Low-Flow Low-Gradient Aortic Stenosis
Long and mid-term data in Low-Flow Low-Gradient Aortic Stenosis (LFLG-AS) are scarce. The present study sought to identify predictors of outcome in a sizeable cohort of patients with LFLG-AS. 76 consecutive patients with LFLG-AS (defined by a mean gradient <40 mmHg, an aortic valve area 641 cm2 and an ejection fraction 6450%) were prospectively enrolled and followed at regular intervals. Events defined as aortic valve replacement (AVR) and death were assessed and overall survival was determined. 44 patients underwent AVR (10 transcatheter and 34 surgical) whilst intervention was not performed in 32 patients, including 9 patients that died during a median waiting time of 4 months. Survival was significantly better after AVR with survival rates of 91.8% (CI 71.1\u201397.9%), 83.0% (CI 60.7\u201393.3%) and 56.3% (CI 32.1\u201374.8%) at 1,2 and 5 years as compared to 84.3% (CI 66.2\u201393.1%), 52.9% (CI 33.7\u201369.0%) and 30.3% (CI 14.6\u201347.5%), respectively, for patients managed conservatively (p = 0.017). The presence of right ventricular dysfunction (HR 3.47 [1.70\u20137.09]) and significant tricuspid regurgitation (TR) (HR 2.23 [1.13\u20134.39]) independently predicted overall mortality while the presence of significant TR (HR 3.40[1.38\u20138.35]) and higher aortic jet velocity (HR 0.91[0.82\u20131.00]) were independent predictors of mortality and survival after AVR. AVR is associated with improved long-term survival in patients with LFLG-AS. Treatment delays are associated with excessive mortality, warranting urgent treatment in eligible patients. Right ventricular involvement characterized by the presence of TR and/or right ventricular dysfunction, identifies patients at high risk of mortality under both conservative management and after AVR