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  • 1
    Online Resource
    Online Resource
    On the evolution of a wave packet in a laminar boundary layer
    Cambridge University Press (CUP) ; 1991
    In:  Journal of Fluid Mechanics Vol. 225 ( 1991-04), p. 575-606
    Details
    In: Journal of Fluid Mechanics, Cambridge University Press (CUP), Vol. 225 ( 1991-04), p. 575-606
    Abstract: The transition process of a small-amplitude wave packet, generated by a controlled short-duration air pulse, to the formation of a turbulent spot is traced experimentally in a laminar boundary layer. The vertical and spanwise structures of the flow field are mapped at several downstream locations. The measurements, which include all three velocity components, show three stages of transition. In the first stage, the wave packet can be treated as a superposition of two- and three-dimensional waves according to linear stability theory, and most of the energy is centred around a mode corresponding to the most amplified wave. In the second stage, most of the energy is transferred to oblique waves which are centred around a wave having half the frequency of the most amplified linear mode. During this stage, the amplitude of the wave packet increases from 0.5 % to 5 % of the free-stream velocity. In the final stage, a turbulent spot develops and the amplitude of the disturbance increases to 27 % of the free-stream velocity. Theoretical aspects of the various stages are considered. The amplitude and phase distributions of various modes of all three velocity components are compared with the solutions provided by linear stability theory. The agreement between the theoretical and measured distributions is very good during the first two stages of transition. Based on linear stability theory, it is shown that the two-dimensional mode of the streamwise velocity component is not necessarily the most energetic wave. While linear stability theory fails to predict the generation of the oblique waves in the second stage of transition, it is demonstrated that this stage appears to be governed by Craik-type subharmonic resonances.
    Type of Medium: Online Resource
    ISSN: 0022-1120 , 1469-7645
    URL: Article
    DOI: 10.1017/S0022112091002185
    Language: English
    Publisher: Cambridge University Press (CUP)
    Publication Date: 1991
    detail.hit.zdb_id: 1472346-3
    detail.hit.zdb_id: 218334-1
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  • 2
    Online Resource
    Online Resource
    The late stages of transition induced by a low-amplitude wavepacket in a laminar boundary layer
    Cambridge University Press (CUP) ; 1997
    In:  Journal of Fluid Mechanics Vol. 340 ( 1997-06-10), p. 395-411
    Details
    In: Journal of Fluid Mechanics, Cambridge University Press (CUP), Vol. 340 ( 1997-06-10), p. 395-411
    Abstract: The evolution of a wavepacket in a laminar boundary layer is studied experimentally, paying particular attention to the stage just prior to the formation of a turbulent spot. The initial stages of development are found to be in very good agreement with previous results and indicate a stage in which the disturbance grows according to linear theory followed by a weakly nonlinear stage in which the subharmonic grows, apparently through a parametric resonance mechanism. In a third stage, strong non-linear interactions are observed in which the disturbance develops a streaky structure and the corresponding wavenumber–frequency spectra exhibit an organized cascade mechanism in which spectral peaks appear with increasing spanwise wavenumber and with frequencies which alternate between zero and the subharmonic frequency. Higher harmonics are also observed, although with lower amplitude than the low-frequency peaks. The final (breakdown) stage is characterized by the appearance of high-frequency oscillations with random phase, located at low-speed ‘spike’ regions of the primary disturbance. Wavelet transforms are used to analyse the structure of both coherent and random small-scale structure of the disturbance. In particular, the breakdown oscillations are also observed to have a wavepacket character riding on the large-amplitude primary disturbance.
    Type of Medium: Online Resource
    ISSN: 0022-1120 , 1469-7645
    URL: Article
    DOI: 10.1017/S0022112097005417
    Language: English
    Publisher: Cambridge University Press (CUP)
    Publication Date: 1997
    detail.hit.zdb_id: 1472346-3
    detail.hit.zdb_id: 218334-1
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  • 3
    Online Resource
    Online Resource
    Second malignancies in early stage laryngeal carcinoma patients treated with radiotherapy
    Cambridge University Press (CUP) ; 2002
    In:  The Journal of Laryngology & Otology Vol. 116, No. 3 ( 2002-03), p. 190-193
    Details
    In: The Journal of Laryngology & Otology, Cambridge University Press (CUP), Vol. 116, No. 3 ( 2002-03), p. 190-193
    Abstract: A retrospective review of 240 patients with T 1 /T 2 squamous cell carcinomas of the larynx was performed. Seventy-two per cent had glottic primaries, 27 per cent had supraglottic tumours and one per cent had subglottic disease. Sixty-nine per cent presented with T 1 disease and 31 per cent had T 2 staged tumours. All patients were treated with definitive radiotherapy between 1973 and 1997. With a median follow-up of 68 months, 68 patients (28 per cent) have developed 72 other cancers. Ten of 68 presented with synchronous primaries (15 per cent). Thirty per cent of glottic patients and 25 per cent of the supraglottic/subglottic patients developed second cancers. The most frequent second malignancy was lung cancer: 28/72 (39 per cent). Fifteen patients developed second head and neck cancers (21 per cent). Other second primary sites included oesophagus (eight), prostate (six), colorectal (five), breast (two) and others (eight). The median time from radiotherapy until the development of a second cancer was 31 months. The Kaplan-Meier survival estimate at five years was significantly less for those patients developing second cancers (55 per cent) compared to those not developing second malignancies (70 per cent), ( p 〈 0.05). The median survival from the development of a second cancer was 14 months. More died as a result of a second cancer (41 patients) than their primary laryngeal cancer (40 patients). Second cancers are common and deadly in patients with early stage laryngeal carcinoma.
    Type of Medium: Online Resource
    ISSN: 0022-2151 , 1748-5460
    URL: Article
    DOI: 10.1258/0022215021910500
    Language: English
    Publisher: Cambridge University Press (CUP)
    Publication Date: 2002
    detail.hit.zdb_id: 2013209-8
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  • 4
    Online Resource
    Online Resource
    Dual stain kit for the microscopic gram classification of ocular infection bacteria
    Cambridge University Press (CUP) ; 1993
    In:  Proceedings, annual meeting, Electron Microscopy Society of America Vol. 51 ( 1993-08-01), p. 248-249
    Details
    In: Proceedings, annual meeting, Electron Microscopy Society of America, Cambridge University Press (CUP), Vol. 51 ( 1993-08-01), p. 248-249
    Abstract: Keratitis and conjunctivitis (infections of the cornea or conjunctiva) are ocular infections caused by various bacteria, fungi, viruses or parasites; bacteria, however, are usually prominent. Systemic conditions such as alcoholism, diabetes, debilitating disease, AIDS and immunosuppressive therapy can lead to increased susceptibility but trauma and contact lens use are very important factors. Gram-negative bacteria are most frequently cultured in these situations and Pseudomonas aeruginosa is most usually isolated from culture-positive ulcers of patients using contact lenses. Smears for staining can be obtained with a special swab or spatula and Gram staining frequently guides choice of a therapeutic rinse prior to the report of the culture results upon which specific antibiotic therapy is based. In some cases staining of the direct smear may be diagnostic in situations where the culture will not grow. In these cases different types of stains occasionally assist in guiding therapy.
    Type of Medium: Online Resource
    ISSN: 0424-8201 , 2690-1315
    URL: Article
    DOI: 10.1017/S0424820100147089
    Language: English
    Publisher: Cambridge University Press (CUP)
    Publication Date: 1993
    SSG: 11
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  • 5
    Online Resource
    Online Resource
    Preface
    Cambridge University Press (CUP) ; 1972
    In:  PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association Vol. 1972 ( 1972), p. v-v
    Details
    In: PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association, Cambridge University Press (CUP), Vol. 1972 ( 1972), p. v-v
    Type of Medium: Online Resource
    ISSN: 0270-8647 , 2327-9486
    URL: Article
    DOI: 10.1086/psaprocbienmeetp.1972.3698956
    RVK:
    CA 1000
    Language: English
    Publisher: Cambridge University Press (CUP)
    Publication Date: 1972
    detail.hit.zdb_id: 2082673-4
    SSG: 11
    SSG: 5,1
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  • 6
    Online Resource
    Online Resource
    Coronavirus disease 2019 (COVID-19) infection prevention practices that exceed Centers for Disease Control and Prevention (CDC) guidance: Balancing extra caution against impediments to care
    Cambridge University Press (CUP) ; 2023
    In:  Infection Control & Hospital Epidemiology
    Details
    In: Infection Control & Hospital Epidemiology, Cambridge University Press (CUP)
    Abstract: In a survey of infection prevention programs, leaders reported frequent clinical and infection prevention practice modifications to avoid coronavirus disease 2019 (COVID-19) exposure that exceeded national guidance. Future pandemic responses should emphasize balanced approaches to precautions, prioritize educational campaigns to manage safety concerns, and generate an evidence-base that can guide appropriate infection prevention practices.
    Type of Medium: Online Resource
    ISSN: 0899-823X , 1559-6834
    URL: Article
    DOI: 10.1017/ice.2023.89
    Language: English
    Publisher: Cambridge University Press (CUP)
    Publication Date: 2023
    detail.hit.zdb_id: 2106319-9
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