45,782 research outputs found

    Adaptive high-order finite element solution of transient elastohydrodynamic lubrication problems

    Get PDF
    This article presents a new numerical method to solve transient line contact elastohydrodynamic lubrication (EHL) problems. A high-order discontinuous Galerkin (DG) finite element method is used for the spatial discretization, and the standard Crank-Nicolson method is employed to approximate the time derivative. An h-adaptivity method is used for grid adaptation with the time-stepping, and the penalty method is employed to handle the cavitation condition. The roughness model employed here is a simple indentation, which is located on the upper surface. Numerical results are presented comparing the DG method to standard finite difference (FD) techniques. It is shown that micro-EHL features are captured with far fewer degrees of freedom than when using low-order FD methods

    Engaging men with penile cancer in qualitative research: reflections from an interview-based study.

    Get PDF
    To explore the challenges of engaging men with penile cancer in qualitative interview research

    THE IMPACT OF PENILE CANCER TREATMENT ON SEXUAL RELATIONSHIPS: A QUALITATIVE ENQUIRY

    Get PDF
    Background: Penile cancer is a rare but highly treatable condition. Current guidance recommends the use of a surgical procedure to excise the primary tumour (and a margin of normal penile tissue). Whilst treatment can be effective, treatment often has a significant impact on a patient's sexual and urinary function, and physical and mental wellbeing. The objective of this study was to explore the impact of treatment for penile cancer on sexual function and relationships. Methods: Qualitative data was collected via narrative video interviews. Maximum variation sampling was used to acquire the widest possible range of experiences. All interviews were recorded using either a digital video recorder or digital audio recorder, transcribed. A method of constant comparison analysis was used to illicit themes and outliers. Results: Twenty seven men were interviewed; mean age at diagnosis = 63 (range = 41-82); Mean number of years post-surgery = 3 (range = 0-15 years) 15 men were married, a further two were in a committed relationship, the remaining 10 were single/widowed. All men had received surgical treatment ranging from circumcision to total penectomy. Just two men had attended any form of psychological therapy. The impact of treatment varied considerably. The majority of men talked about still being able to experience arousal and sexual pleasure in some way. However, for many, penetrative sex was awkward and less gratifying than before treatment. One man who had received a total penectomy was surprised to experience a form of orgasm after surgery. For a number of men, the impact of treatment on their ability to satisfy their sexual partners was a key concern. Men who were able to openly talk with their partners about sex and the impact of the treatment on sexual practice found this a great comfort. Conclusion: The significance of sex for a man can differ considerably between individuals; relationship status, age and life stage are all likely to have a bearing on the role that sex plays in a man life. A diagnosis of cancer can also affect how a man (and his partner) views sex and the level of importance which he attaches to it. For men who are sexually active prior to treatment, surgery will undoubtedly result in changes to sexual practice, however, treatment does not have to result in sexual abstinence

    Interactions between unidirectional quantized vortex rings

    Full text link
    We have used the vortex filament method to numerically investigate the interactions between pairs of quantized vortex rings that are initially traveling in the same direction but with their axes offset by a variable impact parameter. The interaction of two circular rings of comparable radii produce outcomes that can be categorized into four regimes, dependent only on the impact parameter; the two rings can either miss each other on the inside or outside, or they can reconnect leading to final states consisting of either one or two deformed rings. The fraction of of energy went into ring deformations and the transverse component of velocity of the rings are analyzed for each regime. We find that rings of very similar radius only reconnect for a very narrow range of the impact parameter, much smaller than would be expected from geometrical cross-section alone. In contrast, when the radii of the rings are very different, the range of impact parameters producing a reconnection is close to the geometrical value. A second type of interaction considered is the collision of circular rings with a highly deformed ring. This type of interaction appears to be a productive mechanism for creating small vortex rings. The simulations are discussed in the context of experiments on colliding vortex rings and quantum turbulence in superfluid helium in the zero temperature limit

    Energy and urban built form: an empirical and statistical approach

    Get PDF
    The geometrical forms of buildings have important effects on their use of energy. These relationships are explored at the scale of the entire non-domestic building stock of London. A three-dimensional digital model of the city is used to make a series of geometrical measures: building volume, exposed surface area (walls plus roof) and plan depth. These are compared with figures for the consumption of gas and electricity published by the UK Department of Energy and Climate Change (DECC). The comparisons are made at different levels of spatial aggregation, from boroughs to census districts. Strong correlations are demonstrated between exposed surface area and both gas and electricity use. The analysis also provides some evidence of a sharp increase in electricity use in districts with buildings whose depth in plan exceeds 14 m (in which air-conditioning and permanent artificial lighting are typically required). A multiple regression model is used to measure the contribution of these effects to total energy use, as compared with floor area, activities and number of employees

    A census of massive stars in NGC 346. Stellar parameters and rotational velocities

    Full text link
    Spectroscopy for 247 stars towards the young cluster NGC 346 in the Small Magellanic Cloud has been combined with that for 116 targets from the VLT-FLAMES Survey of Massive Stars. Spectral classification yields a sample of 47 O-type and 287 B-type spectra, while radial-velocity variations and/or spectral multiplicity have been used to identify 45 candidate single-lined systems, 17 double-lined systems, and one triple-lined system. Atmospheric parameters (Teff_eff and loggg) and projected rotational velocities (vev_esinii) have been estimated using TLUSTY model atmospheres; independent estimates of vev_esinii were also obtained using a Fourier Transform method. Luminosities have been inferred from stellar apparent magnitudes and used in conjunction with the Teff_eff and vev_esinii estimates to constrain stellar masses and ages using the BONNSAI package. We find that targets towards the inner region of NGC 346 have higher median masses and projected rotational velocities, together with smaller median ages than the rest of the sample. There appears to be a population of very young targets with ages of less than 2 Myr, which have presumably all formed within the cluster. The more massive targets are found to have lower vev_esinii consistent with previous studies. No significant evidence is found for differences with metallicity in the stellar rotational velocities of early-type stars, although the targets in the SMC may rotate faster than those in young Galactic clusters. The rotational velocity distribution for single non-supergiant B-type stars is inferred and implies that a significant number have low rotational velocity (\simeq10\% with vev_e<40 km/s), together with a peak in the probability distribution at vev_e \simeq300 km/s. Larger projected rotational velocity estimates have been found for our Be-type sample and imply that most have rotational velocities between 200-450 km/s.Comment: Accepted by A&

    Johnson-Kendall-Roberts theory applied to living cells

    Get PDF
    Johnson-Kendall-Roberts (JKR) theory is an accurate model for strong adhesion energies of soft slightly deformable material. Little is known about the validity of this theory on complex systems such as living cells. We have addressed this problem using a depletion controlled cell adhesion and measured the force necessary to separate the cells with a micropipette technique. We show that the cytoskeleton can provide the cells with a 3D structure that is sufficiently elastic and has a sufficiently low deformability for JKR theory to be valid. When the cytoskeleton is disrupted, JKR theory is no longer applicable

    An Analysis of Stylistic Trends in Published Kiswahili Short Story Genre

    Get PDF
    Writers express themselves in varied styles regardless of the genre they use as their vehicle of expression. Writing styles can also vary depending on the genre in focus. In this regard, therefore, stylistic issues can be focused upon from a two prong approach; that is from a writer’s centered focus and secondly from a genre-based focus. Kiswahili Short story manifests generic features that are unique to the short story genre only. On the other hand, different writers have used a variety of styles to weave their stories. Some of these styles at times seem to be unique to specific writers. This paper uses stylistic approaches to analyse Kiswahili short stories and exemplifies how stylistic features are applied to the short stories. The paper concludes that Kiswahili short story genre has come of age and indeed continues to grow. As a result, as the paper shows, Kiswahili short story is weaved using a variety of styles that make it more interesting, informative and educative. Most of these styles give Kiswahili short story a unique African rendition that is born out of interweaving both exotic and native African styles. Key Words: Genre, Kiswahili, short story, stylistic approache
    corecore