The preliminary design of a scaled Composite UHBR Fan for a wind tunnel test campaign

AbstractThe ambition of the CA3ViAR project is to design an open test case fan that experiences instability mechanisms, which are representative for ultra-high bypass ratio (UHBR) fans of civil aircrafts, and to perform a comprehensive experimental investigation to measure aerodynamic, aeroelastic and aeroacoustic performance in a wide range of operational conditions. Experimental tests will be performed in the Propulsion-Test-Facility (PTF) of the Institute of Jet Propulsion and Turbomachinery (IFAS) of Technische Universität Braunschweig, Germany. The final objective of the project is to provide an open test case for the entire research community, with geometries, numerical and experimental results to establish a new reference for composite UHBR fan design. This will support the development of new methods and tools for the development of safer, lighter and more efficient composite fans for greener UHBR engines. In this work the preliminary design of the low transonic fan (LTF) to be used as test article, whose main requirement is to be operated in a safe and controlled way in conditions of aerodynamic and/or aeroelastic instability during wind tunnel operations, is presented. More in particular, consolidated aerodynamic design, strategy adopted to drive the structural design, flutter analysis taking into account acoustic reflection at the intake, dynamic and stress analyses, as well as aeroacoustic measurement optimization are presented and discussed. The preliminary mechanical design of composite blades and the rotor hub, together with the rotor instrumentation and related studies to embed sensors in the composite blades, are also part of this article, and complemented by manufacturing trials and demonstration tests give the full picture of all the project activities up to the preliminary design review

The Darlington and Northallerton Long Term Asthma Study: pulmonary function

BACKGROUND: The Darlington and Northallerton Asthma Study is an observational cohort study started in 1983. At that time little was published about long term outcome in asthma and the contribution of change in reversible disease or airway remodelling to any excess deterioration in function. The study design included regular review of overall and fixed function lung. We report the trends over fifteen years. METHODS: All asthmatics attending secondary care in 1983, 1988 and 1993 were recruited. Pulmonary function was recorded at attendance and potential best function estimated according to protocol. Rate of decline was calculated over each 5-year period and by linear regression analysis in those seen every time. The influence of potential explanatory variables on this decline was explored. RESULTS: 1724 satisfactory 5-year measurements were obtained in 912 subjects and in 200 subjects on all occasions. Overall rate of decline (ml/year (95%CI)) calculated from 5-year periods was FEV1 ♂41.0 (34.7–47.3), ♀28.9 (23.2–34.6) and best FVC ♂63.1 (55.1–71.2)ml/year, ♀45.8 (40.0–51.6).The principal association was with age. A dominant cubic factor suggested fluctuations in the rate of change in middle life with less rapid decline in youth and more rapid decline in the elderly. Rapid decline was possibly associated with short duration. Treatment step did not predict rate of deterioration. CONCLUSIONS: Function declined non-linearly and more rapidly than predicted from normal subjects. It reports for the first time a cubic relationship between age and pulmonary function. This should be taken into account when interpreting other articles reporting change in function over time

Hemi-Castaing ligamentoplasty for the treatment of chronic lateral ankle instability: a retrospective assessment of outcome

Purpose: In the treatment of chronic ankle instability, most non-anatomical reconstructions use the peroneus brevis tendon. This, however, sacrifices the natural ankle stabilising properties of the peroneus brevis muscle. The aim of this study was to evaluate the functional outcome of patients treated with a hemi-Castaing procedure, which uses only half the peroneus brevis tendon. Methods: We performed a retrospective cohort study of patients who underwent hemi-Castaing ligamentoplasty for chronic lateral ankle instability between 1993 and 2010, with a minimum of one year follow-up. Patients were sent a postal questionnaire comprising five validated outcome measures: Olerud-Molander Ankle Score (OMAS), Karlsson Ankle Functional Score (KAFS), Tegner Activity Level Score (pre-injury, prior to surgery, at follow-up), visual analog scale on pain (VAS) and the Short Form 36 (SF-36). Results: Twenty patients completed the questionnaire on functional outcome. The OMAS showed good to excellent outcome in 80% and the KAFS in 65%, the Tegner Score improved from surgery but did not reach pre-injury levels, the VAS on pain was 1 of 10 and the SF-36 returned to normal compared with the average population. Conclusions: Even though most patients were satisfied with the results, outcome at long-term follow-up was less favourable compared with the literature on anatomical reconstructions. In accordance with the literature, we therefore conclude that the initial surgical treatment of chronic lateral ankle instability should be an anatomical repair with augmentation (i.e. the Broström-Gould technique) and the non-anatomical repair should be reserved for unsuccessful cases after anatomical repair or in cases where no adequate ligament remnants are available for reconstruction

Cigarette use among Greek athletes

Background: Cigarette smoking is an important risk factor for cardiovascular disease and lung cancer. Exercise improves cardiovascular and pulmonary function and also may play an important role in encouraging people to give up smoking, when appropriate sporting activity is introduced. We investigated smoking habits among Greek students participating in sporting activities. Methods: We interviewed 1003 volunteers with a mean age of 17.9 ± 0.2 years. They included 617 (61.5%) men and 386 (38.5%) women, participating in 30 different sporting activities. A specific questionnaire was used. Results: Of the 1003 volunteers, 104 (10.4%) were current smokers who started smoking at the age of 17.3 ± 0.2 years and smoked 13.6 ± 0.7 cigarettes per day. Among males 9.1% and among females 12.4% were current smokers. Two-thirds (66.4%) of the smokers preferred Marlboro (45.2%) and Camel (21.2%) brands, respectively. Among males, volleyball, kickboxing, track & field and handball and among females, volleyball, dance, gymnastics, and basketball were associated with higher rates of smoking. Students involved in national and international competitions had significantly lower smoking rates. Conclusions: Exercise may be related to a significantly lower prevalence of smoking among students. Smoking cessation programs should encourage sporting activity. Participation at high levels of competition may be significant in preventing the habit of smoking. © 2005 World Health Federation

The intensive care units in greater Athens: Needs and resources

The purpose of this study was to investigate the availability of intensive care unit (ICU) beds and the number of requests, the number and categories of nursing staff, the nursing care required, and the time spent in various nursing activities. Methods: 19 district general hospitals were studied. The characteristics of the units and their nursing personnel were recorded. The availability of ICU beds, the frequency of bed requests, and the way of patient admission in the ICUs were studied retrospectively for I year and prospectively for 2 weeks. The staffing level of direct care for 36 patients was studied to determine the time required for direct nursing care. Results: the distribution of intensive care beds was: GICU 108, CICU 114, PSICU 30. During 1991, 12363 patients were admitted and 12 172 of them were discharged; 3 628 patients stayed less than 2 days while the average length of stay was 12.5 days. In 1992, during the 2-week period, there were 303 requests for an admission to ICUs and of these 150 requests could not be met because of lack of ICU beds. The mean staffing level was 2.3 nurses per bed (to cover the three shifts). The mean nursing time required for direct nursing care of each patient per shift was found to be 6 hours for GICU patients, 5.3 for CICU, and 6.0 for PSICU patients. © 1996 Pearson Professional Ltd

Leptin serum levels in cachectic heart failure patients - Relationship with tumor necrosis factor-alpha system

Cachexia is a strong predictor for mortality in patients with congestive heart failure. To investigate the role of leptin and regulators of apoptosis in cardiac cachexia we compared leptin concentrations and their relation to the TNF system, interleukin 1-beta (TL-1b), and soluble Fas in patients with heart failure with and without cachexia. Patients with cardiac cachexia have increased levels of interleukin-1b compared to non-cachectic heart failure patients [mean(S.E.)=1.11(0.62) vs. 0.02(0.02), P=0.01] and decreased concentrations of leptin [10.79(3.93) vs. 23.24 (8.35), P=0.1]. Leptin levels correlate with TNF-RI in cachectic heart failure patients (r=0.58, P=0.018). The TNF-RI levels were also correlated with Fas, both in all the patients taken together (r=0.5, P=0.006) and in those with cachexia (r=0.52, P=0.036). Our data indicate that more prospective studies are needed to clarify the role of leptin in the pathophysiology of heart failure cachexia. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved