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PubMed1983

An outbreak of acute fever among steam turbine condenser cleaners.

Ten of twelve men who participated in the cleaning of an electric power steam turbine condenser clogged with freshwater sponge experienced an acute febrile illness. Two similar outbreaks have been previously described, one of which has been attributed to the Legionnaires' Disease bacterium. Epidemiologic studies of this case showed a syndrome very similar to the two previously reported episodes. However, the exact etiology for this outbreak has not been identified. Environmental sampling was not initiated until after the cleaning was completed. Subsequent testing did not reveal any likely cause for the outbreak. The delayed onset of symptoms and the nature of the illness pointed to an infectious agent. In the absence of any suitable criteria for employee exposure evaluation, it is suggested that crews cleaning condensers under unusually dirty conditions, especially if eye or respiratory symptoms are reported, should be provided with respiratory protection.

Adult↗
PubMed2004

Epoxy-based production of wind turbine rotor blades: occupational dermatoses.

Occupational dermatoses were investigated in a factory producing rotor blades for wind turbines by an epoxy-based process. In a blinded study design, 603 workers were first interviewed and thereafter clinically examined. Based on a history of work-related skin disease, clinical findings of dermatitis, or both, 325 (53.9%) of the workers were patch tested with a specially profiled occupational patch-test series and the European standard patch-test series. Calculated on all investigated workers, 17.1% of the workers were diagnosed with occupational dermatoses caused by work. Occupational allergic contact dermatitis was found in 10.9% of the workers. The estimated frequency of irritant contact dermatitis caused by work was 6.1%. Dermatitis on the hands was associated with contact allergy to epoxy resin (P = 0.017). The number of days on leave before the clinical examination was negatively associated with the presence of dermatitis (P = 0.001). Among workers employed 7-12 months, the frequency of occupational contact allergy was higher than that among workers employed for </=6 months (P = 0.004). Females both washed their hands more often (P < 0.001) and used more moisturizers/protection creams at work (P < 0.001) than males. No sex differences were found concerning dermatitis on the hands.

Adolescent↗
PubMed1985

The effect of submucosal diathermy to the inferior turbinates on nasal resistance to airflow in allergic and vasomotor rhinitis.

Twenty-one patients with nasal obstruction due to allergic or vasomotor rhinitis were assessed rhinomanometrically before and after the operation of submucosal diathermy to the inferior turbinates. It was found that the operation significantly improved the nasal airway. Most patients with an objective improvement reported a corresponding reduction in nasal obstruction. There was no tendency for patients with allergic rhinitis to be dissatisfied with the operation.

Adolescent↗
PubMed2005

Hand-held turbine spirometer: agreement with the conventional spirometer at baseline and after exercise.

Portable hand-held spirometers are widely used in outpatient clinics and in field surveys when examining children for asthma. However, the validity of the results obtained from the hand-held spirometers has not been assessed in population-based studies. We evaluated the agreement between the forced expiratory volume (FEV1) values got by the conventional flow volume spirometer (FVS) and the pocket-sized turbine spirometer (TS) at baseline and after exercise, among the 212 children screened for asthma and asthma-like symptoms from a population of 1633 school-aged children. The comparison was made between and within three diagnostic groups: clinical asthma (n = 34), possible asthma (n = 31), and controls (n = 147). In general, the differences in FEV1 between the FVS and the TS were small. For all children, the mean difference in FEV1 and the limits of agreement (difference +/-2 s.d.) was 0.05 l (0.23 to -0.13) at baseline and 0.06 l (0.24 to -0.12) after exercise. No significant differences were observed in the agreement between the diagnostic groups. In conclusion, although FEV1 results obtained by the hand-held spirometer are not interchangeable with those by the conventional spirometer, they are in reasonable agreement. The agreement is similar both at baseline and after exercise, and is not influenced by the presence of asthma.

Asthma↗
PubMed2001

Heat transfer near turbine nozzle endwall.

This paper gives an overview and reviews recent findings concerning turbine endwall cooling in the literature. The text below begins with a brief discussion of the secondary flows and heat transfer around cascade endwall. This will be followed by a review of recent developments in cooling concepts and related heat transfer results. Key topics include: film cooling, upstream bleeding, endwall contouring, and leakage through component interfaces.

Journal Article↗
PubMed2001

Cooling systems for ultra-high temperature turbines.

This paper describes an introduction of research and development activities on steam cooling in gas turbines at elevated temperature of 1500 C and 1700 C level, partially including those on water cooling. Descriptions of a new cooling system that employs heat pipes are also made. From the view point of heat transfer, its promising applicability is shown with experimental data and engine performance numerical evaluation.

Journal Article↗
PubMed2001

Numerical investigation of heat transfer on film-cooled turbine blades.

The accurate heat transfer prediction of film-cooled blades is a key issue for the aerothermal turbine design. For this purpose, advanced numerical methods have been developed at Snecma Moteurs. The goal of this paper is the assessment of a three-dimensional Navier-Stokes solver, based on the ONERA CANARI-COMET code, devoted to the steady aerothermal computations of film-cooled blades. The code uses a multidomain approach to discretize the blade to blade channel with overlapping structured meshes for the injection holes. The turbulence closure is done by means of either Michel mixing length model or Spalart-Allmaras one transport equation model. Computations of thin 3D slices of three film-cooled nozzle guide vane blades with multiple injections are performed. Aerothermal predictions are compared to experiments carried out by the von Karman Institute. The behavior of the turbulence models is discussed, and velocity and temperature injection profiles are investigated.

Journal Article↗
PubMed2001

Verifying heat transfer analysis of high pressure cooled turbine blades and disk.

To demonstrate cooling and heat transfer technology, a core engine test was conducted with a turbine inlet temperature 1700 degrees C. Measurement data were compared with predictions for a vane, a blade, and a disk. Measured cooling effectiveness of the blade and the vane agreed well with predictions. CFD analysis was carried out for verification of the heat transfer coefficient which was adopted from a heat conduction analysis over the disk. The CFD model including bolt heads showed better results than an axisymmetric model.

Journal Article↗
PubMed1993

Aspects of the design of modern dental air turbine handpieces.

Air turbine handpieces are manufactured with a wide range of alternative design features which may influence their suitability for particular clinical procedures. In this article a general account of these features is presented and their advantages and disadvantages are discussed. Some deficiencies in current methods of stating equipment specifications are reported and suggested improvements are given. Where appropriate, general recommendations are made regarding handpiece selection for clinical practice.

Air Pressure↗
PubMed1994

Dynamic measurement of the torque-speed characteristics of dental high speed air turbine handpieces.

The first requirement for adequate performance of an air turbine handpiece is sufficient power. Suppliers of such handpieces do not provide data on the power produced by their equipment. A method for determining the torque, speed and hence power during simulated operation is described. Forty-one new and used handpieces were tested. Maximum speeds up to 500,000 rpm, maximum torques up to 2.33 N.mm and maximum power up to 29.6 watt were observed. The maximum power was produced at between 49 and 79 per cent of the free-running speed. A relationship between maximum power and stall torque was noted. The maximum torque is at stall for ball-bearing units. The stall torque can be easily determined by a simple stall torque test which is described. Using this test, the performance of handpieces can be easily checked in the clinic. The one air-bearing handpiece tested performed in a manner similar to the others, except that stall occurred below 60,000 rpm.

Dental High-Speed Equipment↗
PubMed1970

Mechanochemical turbine: a new power cycle.

A basic thermodynamic cycle for the production of mechanical power from materials that may be made to contract forcibly and reversibly is described. The cycle differs from existing mechanical power cycles which generally employ expanding fluid as working substances. A "contraction turbine" operating on this cycle has been devised, which has collagen fiber as its working substance and salt solution as fuel and produces mechanical work directly from chemical free energy. Direct conversion of chemical to mechanical energy is routinely effected in muscle but not in usual man-made engines.

Bromides↗
PubMed1979

Nonpneumonic, short-incubation-period Legionellosis (Pontiac fever) in men who cleaned a steam turbine condenser.

Pontiac fever affected ten men who had cleaned a steam turbine condenser with compressed air. Previous epidemics of Pontiac fever and Legionnaires' disease--both caused by Legionella Pneumophila (proposed sp. nov.)--involved "airborne spread" from air-conditioning cooling towers or evaporative condensers. Aerosols of contaminated water in heat-rejection systems appear to be important sources of epidemic legionellosis.

Adolescent↗
PubMed1987

Evaluation of the turbine pocket spirometer.

A compact electronic spirometer, the turbine pocket spirometer, which measures the FEV1, forced vital capacity (FVC), and peak expiratory flow (PEF) in a single expiration, was compared with the Vitalograph and the Wright peak flow meter in 99 subjects (FEV1 range 0.40-5.50 litres; FVC 0.58-6.48 l; PEF 40-650 l min-1). The mean differences between the machines were small--0.05 l for FEV1, 0.05 l for FVC, and 11.6 l min-1 for PEF, with the limits of agreement at +/- 0.25 l, +/- 0.48 l, and +/- 52.2 l min-1 respectively. The wide limits of agreement for the PEF comparison were probably because of the difference in the technique of blowing: a fast, long blow was used for the pocket spirometer and a short, sharp one for the Wright peak flow meter. The FEV1 and FVC showed a proportional bias of around 4-5% in favour of the Vitalograph. The repeatability coefficient for the pocket spirometer FEV1 was 0.18 l, for FVC 0.22 l, and for PEF 31 l min-1. These compared well with the repeatability coefficients of the Vitalograph and the Wright peak flow meter, which gave values of 0.18 l, 0.28 l, and 27 l min-1 respectively. At flow rates of over 600 l min-1 the resistance of the pocket spirometer marginally exceeded the American Thoracic Society recommendations. The machine is easy to operate and portable, and less expensive than the Vitalograph and Wright peak flow meter combined. It can be recommended for general use.

Evaluation Studies as Topic↗
PubMed1980

The prevalence of Brodetella bronchiseptica and turbinate (conchal) atrophy in English pig herds in 1978-79.

Examination of pigs (eight to 10 per farm) slaughtered between December 1978 and March 1979 at abattoirs in southern England indicated that infection with Bordetella bronchiseptica was widespread. The organism was recovered from the nasal cavity of 424 out of 844 (50 per cent) of such pigs and these were distributed among 79 out of 86 (91 per cent) of the herds submitting animals. The sensitivity to sulphonamide or potentiated sulphonamide of 255 of these strains was determined: in 20 out of 70 (25 per cent) herds there was partial or complete resistance to the former drug and, in 16 out of 79 (20 per cent), to the latter also. Despite this general level of infection and bacterial resistance the prevalence and severity of turbinate atrophy was less than in a survey undertaken by others in 1974. Thus about 74 per cent of pigs had no or minor atrophy only and about 10 per cent severe lesions. Some 10 per cent of the farms sent groups in which the majority of the pigs had severe atrophy.

Animals↗
PubMed1990

Evaluation of a turbine flow meter (Ventilometer Mark 2) in the measurement of ventilation.

We have evaluated a turbine flow meter (Ventilometer Mark 2, PK Morgan, Kent, UK) at low flow rates and levels of ventilation which are likely to be encountered during exercise in patients with chronic respiratory disease. Pulsatile flows were generated from a volume-cycled mechanical ventilator, the flow wave-form was modified by damping to simulate a human breathing pattern. Comparative measurements of ventilation were made whilst varying tidal volume (VT) from 0.22 to 1.131 and respiratory rate (fR) from 10 to 35 min-1. At lower levels of ventilation the instrument tended to underread especially with increasing fR. The calibration factor must be adjusted to match the level of ventilation if the measurement errors are to be within 5%.

Calibration↗
PubMed2006

A rare case of sarcoidosis involving the middle turbinates: an incidental diagnosis.

BACKGROUND: Sarcoidosis is a chronic, systemic granulomatous disease of unknown etiology that features noncaseating granulomas in many body regions. Sinonasal involvement is rare but is also suspected to be underreported. CASE PRESENTATION: We present the case of a 39-year-old woman who was incidentally diagnosed with isolated sarcoidosis involving the middle turbinates. Histopathologic examination of resected concha bullosa material and an extensive panel of diagnostic tests revealed a diagnosis of isolated sarcoidosis. Since no systemic manifestations were detected, topical corticosteroid (nasal spray) was administered in the postoperative period. Throughout the 12 months after surgery, the patient remained free of symptoms and all nasal endoscopy examinations were normal. CONCLUSION: Although isolated nasal involvement of sarcoidosis is rare, otorhinolaryngologists should consider this condition in a differential diagnosis for sinonasal complaints.

Journal Article↗
PubMed2005

Phase-locked two-line OH planar laser-induced fluorescence thermometry in a pulsating gas turbine model combustor at atmospheric pressure.

Two-line OH planar laser-induced fluorescence (PLIF) thermometry was applied to a swirling CH4/air flame in a gas turbine (GT) model combustor at atmospheric pressure, which exhibited self-excited combustion instability. The potential and limitations of the method are discussed with respect to applications in GT-like flames. A major drawback of using OH as a temperature indicator is that no temperature information can be obtained from regions where OH radicals are missing or present in insufficient concentration. The resulting bias in the average temperature is addressed and quantified for one operating condition by a comparison with results from laser Raman measurements applied in the same flame. Care was taken to minimize saturation effects by decreasing the spectral laser power density to a minimum while keeping an acceptable spatial resolution and signal-to-noise ratio. In order to correct for the influence of laser light attenuation, absorption measurements were performed on a single-shot basis and a correction procedure was applied. The accuracy was determined to 4%-7% depending on the location within the flame and on the temperature level. A GT model combustor with an optical combustion chamber is described, and phase-locked 2D temperature distributions from a pulsating flame are presented. The temperature variations during an oscillation cycle are specified, and the general flame behavior is described. Our main goals are the evaluation of the OH PLIF thermometry and the characterization of a pulsating GT-like flame.

Journal Article↗