Improvement of propeller static thrust estimation

The problem of improving the performance estimation of propellers operating in the heavily loaded static thrust condition was studied. The Goldstein theory was assessed as it applies to propellers operating in the static thrust. A review of theoretical considerations is presented along with a summary of the attempts made to obtain a numerical solution. The chordwise pressure distribution was determined during operation at a tip speed of 500 ft/sec. Chordwise integration of the pressures leads to the spanwise load distribution and further integration would give the axial thrust

Improvement of propeller static thrust estimation Final report, Jul. 1, 1964 - Aug. 31, 1965

Research facility development for propeller thrust and torque measurements under static thrust condition

Tests on propellers under static thrust conditions

Dynamometer tests of propellers under static thrust condition

Quality of life temporarily improved in patients in whom the diagnosis chronic mesenteric ischemia wasn’t confirmed after multidisciplinary evaluation in a tertiary referral centre

Objectives: Chronic Mesenteric Ischemia (CMI) is a disease in which abdominal symptoms are caused by insufficient mesenteric blood supply. Treatment results in improved quality of life (QoL). To put these results into perspective, the QoL of patients with symptoms potentially complying with CMI but without confirmation of the diagnosis was studied from six months up to four years.Methods: Between May and July 2020 follow-up questionnaires were sent to 144 patients that were suspected of CMI but in whom the diagnosis was not confirmed after a thorough multidisciplinary evaluation in a CMI expert centre. The baseline QoL was measured at first presentation. Three cohorts were included: 50 patients with a follow-up of six months, 45 patients with a follow-up of two years, and 49 patients with a follow-up of four years were invited to participate. The QoL was measured on a 100 points Visual Analogue Scale (VAS). A minimal clinically important difference of 7.5 was used as non-inferiority threshold.Results: The response rates were 34/50 (68%), 33/45 (73%), and 34/49 (69%). QoL improved in the six months group, with a mean change of 19 in VAS score (95% CI 11-27), in which baseline QoL was inferior to the QoL at follow-up (lower bound 95% CI above >7.5 threshold). The change in QoL was inconclusive in the other two groups, respectively 15 (95% CI 6-24) and 3 (95% CI -6-13). Furthermore, there was no significant change in QoL between patients without mesenteric stenosis and with one or two vessel stenosis (P=0.36) and between patients with occlusive stenosis and anatomic Median Arcuate Ligament Syndrome (MALS) (P=0.53).Conclusion: The QoL of patients suspected for CMI was clinically significantly improved after six months without additional treatment. However, this improvement faded completely after four years

Adherence to Blended or Face-to-Face Smoking Cessation Treatment and Predictors of Adherence:Randomized Controlled Trial

Background: Blended face-to-face and web-based treatment is a promising way to deliver smoking cessation treatment. Since adherence has been shown to be an indicator of treatment acceptability and a determinant for effectiveness, we explored and compared adherence and predictors of adherence to blended and face-to-face alone smoking cessation treatments with similar content and intensity. Objective: The objectives of this study were (1) to compare adherence to a blended smoking cessation treatment with adherence to a face-to-face treatment; (2) to compare adherence within the blended treatment to its face-to-face mode and web mode; and (3) to determine baseline predictors of adherence to both treatments as well as (4) the predictors to both modes of the blended treatment. Methods: We calculated the total duration of treatment exposure for patients (N=292) of a Dutch outpatient smoking cessation clinic who were randomly assigned either to the blended smoking cessation treatment (n=130) or to a face-to-face treatment with identical components (n=162). For both treatments (blended and face-to-face) and for the two modes of delivery within the blended treatment (face-to-face vs web mode), adherence levels (ie, treatment time) were compared and the predictors of adherence were identified within 33 demographic, smoking-related, and health-related patient characteristics. Results: We found no significant difference in adherence between the blended and the face-to-face treatments. Participants in the blended treatment group spent an average of 246 minutes in treatment (median 106.7% of intended treatment time, IQR 150%-355%) and participants in the face-to-face group spent 238 minutes (median 103.3% of intended treatment time, IQR 150%-330%). Within the blended group, adherence to the face-to-face mode was twice as high as that to the web mode. Participants in the blended group spent an average of 198 minutes (SD 120) in face-to-face mode (152% of the intended treatment time) and 75 minutes (SD 53) in web mode (75% of the intended treatment time). Higher age was the only characteristic consistently found to uniquely predict higher adherence in both the blended and face-to-face groups. For the face-to-face group, more social support for smoking cessation was also predictive of higher adherence. The variability in adherence explained by these predictors was rather low (blended R-2 =0.049; face-to-face R-2 =0.076). Within the blended group, living without children predicted higher adherence to the face-to-face mode (R-2 =0.034), independent of age. Higher adherence to the web mode of the blended treatment was predicted by a combination of an extrinsic motivation to quit, a less negative attitude toward quitting, and less health complaints (R-2 =0.164). Conclusions: This study represents one of the first attempts to thoroughly compare adherence and predictors of adherence of a blended smoking cessation treatment to an equivalent face-to-face treatment. Interestingly, although the overall adherence to both treatments appeared to be high, adherence within the blended treatment was much higher for the face-to-face mode than for the web mode. This supports the idea that in blended treatment, one mode of delivery can compensate for the weaknesses of the other. Higher age was found to be a common predictor of adherence to the treatments. The low variance in adherence predicted by the characteristics examined in this study suggests that other variables such as provider-related health system factors and time-varying patient characteristics should be explored in future research

A telecare programme for self-management of COPD exacerbations and promotion of an active lifestyle

Objective: The Condition Coach (CoCo) is a technology-supported care programme for self-management of COPD exacerbations and for promotion of an active lifestyle. The objective is to investigate the added value of the telecare programme in terms of clinical changes compared to usual care, and in addition, to evaluate its use and acceptance. Intervention: CoCo consists of four modules: 1) activity coach for ambulant activity registration and real-time feedback to improve daily activity behaviour, 2) web-based exercise programme set up by the patient’s primary care physiotherapist, 3) self-treatment of COPD exacerbations via a triage diary on the webportal that provides advice to start medication when necessary, and 4) teleconsultation via the webportal. The latter is accessible for the patient and the involved primary and secondary care professionals. Methods: Twenty-nine COPD patients with ≥3 exacerbations or 1 hospitalization in the past 2 years are randomly assigned to either the intervention group (CoCo programme for 9 months) or the control group (usual care). Exacerbations, activity level, exercise capacity, symptom levels, health status and quality of life are assessed to evaluate clinical changes. Page hits on the webportal show the use of the programme, and the Unified Theory of Acceptance & Use of Technology explains usage behaviour. Results: Preliminary findings show that the webportal is highly accessed by the patients (90% of the days) with good usability (median 5.8, 7-point Likert). Remaining data will be collected in the upcoming months. Conclusions: The CoCo programme has potential as the intervention is highly used and accepted. Final results are expected in July 2013