785 research outputs found
Damage to human hearing by airborne sound of very high frequency or ultrasonic frequency
No full textThis literature review examines the audiological, occupational hygiene and industrial safety literature on the subjective and auditory effects of audible sound in the very high frequency range (10-20 kHz) and also in the inaudible ultrasonic range (greater than 20 kHz, generally thought to be the upper frequency limit of young normal hearing). Exposure limits have been proposed, with the intent of avoiding any subjective effects and any auditory effects, in any exposed individuals. The evolution of these internationally recognised Damage Risk Criteria and Maximum Permitted Levels has been examined critically. Conclusions and recommendations are offered in respect of hearing damage and adverse subjective effects caused by sounds outside the customary frequency range for occupational noise exposure assessments. This report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the author and do not necessarily reflect HSE policy
Gravity tectonics in Eastern Cadore and Western Carnia, (respectively provinces of Belluno and Udine), NE Italy : (with additional notes on the geochemistry of lead)
No full textIn this thesis the results are discussed of five summers
of fieldwork, (1963-1967), carried out by the
author in the areas of Eastern Cadore, (Prov. of
Belluno) and Western Carnia (Prov. of Udine), NE
Italy.
During the first and the second summer the research
was made with the aid of some B.Sc.'s in geology of
the University of Utrecht.
The purpose of this study was to give a tectonic interpretation
of this area in the Southeastern Alp
Gender differences in self-reported late effects, quality of life and satisfaction with clinic in survivors of lymphoma
No full textObjectives: gender differences in perceived vulnerability to late effects and views about follow-up among cancer survivors have received little attention. As lymphoma affects both genders similarly, we compared the consequences of cancer (late effects, perceived vulnerability and quality of life (health-related quality of life (HRQoL)), and satisfaction with clinic visits between genders.Methods: a cohort of 115 younger adults (18–45 years, >5 years disease-free survival), who had been treated for lymphoma participated. Questionnaires (n = 91) were completed before and after (n = 62) routine consultant-led appointments. Survivors (n = 24) without appointments were recruited by post. Questionnaires included HRQoL, late effects, perceived vulnerability, issues survivors wanted to discuss and reported discussing in clinic, time waiting in clinic and consultation satisfaction.Results: there were no gender differences in number of self-reported late effects or perceived vulnerability. Men with more late effects reported worse psychological HRQoL (r = 0.50, p<0.001). While men wanted to discuss more topics than they did, women were able to discuss the topics they wanted (ANOVA, p = 0.01). Multiple regression analyses showed a shorter wait in clinic (r = ?0.46, p = 0.009) and discussing more topics (r = 0.34, p = 0.06) explained 30.6% of the variance in consultation satisfaction for men.Conclusions: issues surrounding follow-up provision are increasingly important given the length of survival in young adults following treatment for lymphoma. Men may experience poor psychological well-being due to distress about unanswered concerns. Consideration of their concerns should be prioritised, given that satisfaction and ultimately continued attendance at clinic and HRQoL may be dependent on the extent to which follow-up meets survivors' expectation
Instantaneous planar pressure determination from PIV in turbulent flow
No full textThis paper deals with the determination of instantaneous planar pressure fields from velocity data obtained by particle image velocimetry (PIV) in turbulent flow. The operating principles of pressure determination using a Eulerian or a Lagrangian approach are described together with theoretical considerations on its expected performance. These considerations are verified by a performance assessment on a synthetic flow field. Based on these results, guidelines regarding the temporal and spatial resolution required are proposed. The interrogation window size needs to be 5 times smaller than the flow structures and the acquisition frequency needs to be 10 times higher than the corresponding flow frequency (e.g. Eulerian time scales for the Eulerian approach). To further assess the experimental viability of the pressure evaluation methods, stereoscopic PIV and tomographic PIV experiments on a square cylinder flow (ReD = 9,500) were performed, employing surface pressure data for validation. The experimental results were found to support the proposed guidelines.Aerospace Engineerin
Praktijkvariatie in het gebruik van remifentanil tijdens de partus: Een beeld van de toepassing in de Nederlandse ziekenhuizen = [Practice application of remifentanil during labor: An overview of its application in Dutch hospitals]
No full textDoelOnderzoeken (a) frequentie van het gebruik van patiëntgecontroleerde toediening van remifentanil (remifentanil-PCA) durante partu in Nederland; (b) wat motieven zijn om remifentanil-PCA al dan niet aan te bieden; (c) voor welke vrouwen remifentanil-PCA beschikbaar is; en (d) welke maternale monitoring wordt toegepast.OpzetBeschrijvend vragenlijstonderzoek.MethodeAlle 81 Nederlandse ziekenhuizen met een verlosafdeling ontvingen een vragenlijst over de volgende onderwerpen: (a) beschikbare methoden voor farmacologische pijnbehandeling; (b) motieven van gynaecologen om remifentanil-PCA wel of niet aan te bieden; (c) de doelgroep voor remifentanil-PCA; (d) maternale monitoring; en (e) Perined-gegevens uit 2016. Wij vroegen de ziekenhuisapothekers naar aantallen ampullen remifentanil die zij in de periode 2016-2017 geleverd hadden.ResultatenDe vragenlijst werd door 81 gynaecologen (100%) ingevuld. In 59 (73%) van de 81 ziekenhuizen was remifentanil-PCA beschikbaar. In deze ziekenhuizen werd remifentanil-PCA bij gemiddeld 23% van de partussen toegepast (uitersten: 16-56%). In 34 (58%) van deze 59 ziekenhuizen was remifentanil-PCA voor alle vrouwen beschikbaar en in 25 (42%) voor een selecte groep. De meest genoemde motieven om remifentanil-PCA beschikbaar te stellen waren ‘de wenselijkheid van een alternatief voor epidurale analgesie’ en ‘op verzoek van zwangeren’, respectievelijk 55 keer (93%) en 46 keer (78%). In ziekenhuizen waar remifentanil-PCA niet beschikbaar was, waren ‘betere pijnbehandeling door epidurale analgesie’, ‘het risico op ernstige maternale bijwerkingen’ en ‘onvoldoende mogelijkheden voor observatie op verloskamers’ de belangrijkste motieven voor dit beleid.ConclusieEr is aanzienlijke variatie in de toepassing van remifentanil-PCA durante partu in Nederland. Remifentanil-PCA is in het merendeel van de ziekenhuizen beschikbaar voor alle vrouwen. De belangrijkste motieven van gynaecologen zijn ‘de wenselijkheid van een alternatief voor epidurale analgesie’ en ‘op verzoek van zwangeren’
Stability relations of antimony and arsenic compounds in the light of revised and extended Eh-pH diagrams
No full textDynamic pitching effect on a laminar separation bubble
No full textThe unsteady effect of a periodic pitching motion on the characteristic of a laminar separation bubble on the suction side of a SD7003 aerofoil is investigated by means of time-resolved planar and tomographic particle image velocimetry. The measurements provide information on the separation, transition and vortex roll-up onset as well as the spanwise distribution of vortical structures, for both the dynamic pitching between 4° and 8° and corresponding cases at a static pitch angle. During pitching, a clear hysteresis behaviour is observed for the vortex roll-up position and shedding frequency, showing a strongly delayed recovery of the shear layer with respect to the steady aerofoil case. The development of the shear layer transition exhibits initially 2D Kelvin–Helmholtz rollers that are interrupted, forming ?-shaped rollers, which eventually evolve into 3D arch-shaped hairpin structures. The 3D analysis of undulated rollers allowed the determination of the rollers streamwise spatial separation for both static and pitching aerofoil case
Assessment of flow around flying mosquito using computational fluid dynamics
No full textAerospace EngineeringAerodynamics, Wind Energy & PropulsionAerodynamic
Structural modelling and numerical analysis of dynamic passive flow control mechanisms in flight feathers
No full textWithin 100 years of the Wright Brother's first flight, we are already approaching the top of aviation’s technological S-curve. Breakthrough technical improvements have resulted in an undeniable increase in efficiency and range, but today’s aircrafts are still relatively inefficient resulting in a large amount of air and noise pollution. In order to aid further new advancements, in this thesis I set out drawing inspiration from nature - specifically birds; to understand how through more than 150 million years of evolution they came to be the most efficient flying creatures we know. The work presented in this thesis is related to the structural modeling and numerical analysis of the primary feather of the western jackdaw (Corvus monedula) to hypothesize its passive deformations under varying morphology and aerodynamic loading. Starting with Computed Micro-Tomograph scans of a primary feather, several techniques were devised towards realizing the detailed micro – and macro - structure of the feather. Modular capabilities of the model allow for rapidly creating morphological variants of the feather. This is the first attempt to model with such high detail the structural response of the micro-structures of flight feathers. Existing experimental or numerical investigations used highly simplified forms of the feathers structure, allowing the analysis of only stand-alone aspects of deformation dynamics of various avian species. Consequently, these low fidelity models failed to capture how individual sub-micron deformations collectively form the passive response of the feather. Passive dynamic deformation of the feathers micro-structures under increasing load revealed an initial decrease and then and increase in nose droop, overall profile camber and transmissivity of the vanes in order to limit flow separation. Response of feather structures due to change in microstructural morphology revealed high stresses at low loading conditions caused due to their reduced strength and rigidity. Buckling of the barbs at their kink zones was found and is attributed to aforementioned morphological changes and the large and unsteady pressure gradients caused as a result. Based on numerical quantification and evidences, the conclusion of this thesis presents a detailed hypothesis on the series of events and interactions which define the mechanics of dynamic passive flow control abilities of primary flight feathers.Aerospace EngineeringFlight Performance and Propulsio
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