Distortion of thin shells due to rapid temperature changes     

John F. Doyle  Lyndon Hadley-Coates 《Ocean Engineering》1986,13(2)

A mathematical model which predicts pressure changes and resultant hull distortion due to variations in temperature of a thin closed shell is presented. The model is of general application but in this paper it is specifically applied to the case of a small sailing boat whose bouyancy depends on the fact that the hull is effectively a water-tight shell made of GRP. In extreme climates such as vessel experiences large temperature changes on launching and beaching and pressure differentials of the order of 2 psi can result. The design of the hull incorporates a small vent hole to relieve the pressure build-ups but the recommended diameter is shown to be too small to avoid damage. Reasons for structural failures, which have frequently been observed, are presented.  相似文献   

Gold nanoparticles and oxidative stress in Mytilus edulis     

Tedesco S  Doyle H  Redmond G  Sheehan D 《Marine environmental research》2008,66(1):131-133

Little is known about potential environmental impact of nanoparticles. Gold nanoparticles can cause unexpected biological responses. Here, Mytilus edulis were exposed (24h) to gold-citrate nanoparticles (GNP), menadione and both compounds simultaneously (GNP/menadione). Protein ubiquitination and carbonylation were determined in gill, mantle and digestive gland, along with traditional oxidative stress biomarkers; catalase activity and neutral red retention time assay (haemolymph). 2DE gels were performed on gill proteins (menadione; GNP/menadione). Our results reveal that GNP may induce oxidative stress.  相似文献   

Modelling near-IR spectra and mid-IR dust emission of Mira variables at different phases     

A. Lobel  S. Bagnulo  J. G. Doyle  C. Power 《Monthly notices of the Royal Astronomical Society》2000,317(2):391-405

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Multidisciplinary investigations at Stalag Luft III allied prisoner‐of‐war camp: The site of the 1944 “great escape,” Zagan,Western Poland     

J.K. Pringle  P. Doyle  L.E. Babits 《Geoarchaeology》2007,22(7):729-746

Stalag Luft III, situated in Zagan, Poland (formerly eastern Germany), was the site of a World War II Allied aviator prisoner of war (POW) camp famous for repeat escape attempts—notably the mass escape of 76 POWs in March 1944, shown in the 1963 film “The Great Escape.” The site has had little attention to date because it was within restricted military training grounds until 1992. This paper reports on attempts to locate the undiscovered “Dick” escape tunnel (the “Tom” and “Harry” tunnels from the same escape attempt were discovered and destroyed by camp authorities). Geological and geophysical surveys located hut 122, which contained the “Dick” entrance shaft. Subsequent archaeological investigations included surface artifact collection and inspection of the rubble‐filled, tunnel entrance shaft. Excavations to a depth of 10 m through yellow glacio‐fluvial sand resulted in the discovery of the refilled “Dick” tunnel with intact bed‐board shoring and ventilation system. Our investigation provides valuable insights into POW escape efforts. © 2007 Wiley Periodicals, Inc.  相似文献   

Heterogeneous andesite–dacite ejecta in 26–16.6 ka pyroclastic deposits of Tongariro Volcano,New Zealand: the product of multiple magma-mixing events     

Phil Shane  Louise R. Doyle  Ian A. Nairn 《Bulletin of Volcanology》2008,70(4):517-536

The previously poorly documented 26–16.6 ka interval of pyroclastic volcanism from Tongariro Volcano is marked by three distal lapilli fall units (Rt1-3) exposed in ring-plain deposits. The distal Rt1-3 units are tentatively correlated to proximal scoria deposits on the upper slopes of North Crater based on their dispersal patterns, petrography and geochemistry. Lapilli in each of the Rt1-3 deposits are characterised by variable groundmass crystallinity, vesicularity and colour within individual clasts. Matrix glasses are mostly microlite-free, and compositionally diverse across the deposits (SiO₂ = 62–75 wt%), with wide composition ranges occurring within single clasts. The glasses represent different melts that were mingled and mixed shortly before eruption; a finding supported by widely variable Fe–Ti oxide equilibrium temperature estimates (∼830–1,200°C). Ranges of 30–160°C (typically 70°C) occur within individual clasts. Some clinopyroxene crystals display Mg-rich (∼Mg #88) rim zones around homogeneous low-Mg (∼Mg #68) cores, with abrupt transition zones. This zoning is interpreted as resulting from the injection of a more mafic melt into a stagnating, resident magma. Crystal-melt equilibria indicate that several episodes of mafic intrusion occurred, to produce hybrid melts with zoned crystals forming isolated ponds within the resident magma. Variable mixing from the percolation of melts and the coalescence of melt ponds would explain the wide range of melt compositions and equilibrium temperatures observed in the ejecta. The magma heterogeneity was preserved by quenching on prompt eruption, with much of the short-duration chaotic mixing of melts and crystals occurring in the conduit. The Rt1-3 eruptions were from an open magmatic system consisting of one or more long-lived stagnant crystal mush zones, from which eruptions were rapidly triggered by new injections of mafic magmas from greater depths. A similar pattern of magmatic dynamics was observed in the much smaller 1995 eruptions of the neighbouring Ruapehu Volcano.  相似文献   

An alternative measure of discharge effectiveness     

Martin W. Doyle  Catherine A. Shields 《地球表面变化过程与地形》2008,33(2):308-316

Since 1960, geomorphic effectiveness has been quantified by analytically combining measures of the frequency and the magnitude of geomorphic processes, most often for the case of sediment yield in rivers via the calculation of effective discharge, Q_eff. Here we leverage the Q_eff analysis approach to develop an alternative metric, the functional‐equivalent discharge Q_fed, which is the discharge that will reproduce the magnitude of the sediment load generated by the full hydrologic distribution. Q_fed is intended to be a more representative metric of hydrologic variability than Q_eff: whereas Q_eff provides a measure of the effectiveness of individual flow rates, Q_fed incorporates a measure of the average effectiveness of the entire flow distribution. We develop an analytical approximation of Q_fed based on relatively few parameters, apply the approach to a set of suspended sediment load data and describe how Q_fed varies broadly with sediment and hydrologic conditions. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

A multi-scale simulation of an extreme downslope windstorm over complex topography     

J. D. Doyle  M. A. Shapiro 《Meteorology and Atmospheric Physics》2000,74(1-4):83-101

Summary A severe localized windstorm, with near-surface winds > 60 ms⁻¹, occurred in an isolated valley within the Alpine mountains (> 1800 m) of central Norway on 31 January 1995. A multi-scale numerical simulation of the event was performed with the Naval Research Laboratory (NRL)’s Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS), configured with four nested grids telescoping down to 1-km horizontal resolution. The windstorm occurred in response to topographic blocking and deformation of a lower-tropospheric warm front and attendant jet (> 35 ms⁻¹ at 2 km). The key findings are: i) mountain wave resonance and amplification arising from the interaction of the surface-based front and jet with complex orography, ii) sensitivity of the wave response to differential diabatic heating (vertical) gradients above the front, and iii) trapped response within the layer of large frontal stratification in the lower troposphere and subsequent amplification consistent with the theoretically-established two-layer windstorm analogue of Durran (1986). Received September 29, 1999 Revised December 30, 1999  相似文献   

Herschel out-of-field stray-light characterization     

U. Klaas  K. Okumura  M. Ferlet  T. Müller  M. Sanchez-Portal  B. Altieri  D. Doyle  G. L. Pilbratt 《Experimental Astronomy》2014,37(2):331-345

Out-of-field stray-light spots of the Herschel telescope optics relative to the PACS and SPIRE instrument apertures were modeled by ray tracing simulations with the Advanced Systems Analysis Program (ASAP, by Breault Research Organization) prior to launch. The predicted stray-light behaviour was verified by dedicated stray-light calibration observations in-flight. This resulted in a special feature of the Herschel Science Mission Planning Software, marking the sky positions of stray-light spots by the very bright infrared planetary sources Venus, Mars, Jupiter, and Saturn, as well as the Moon, thus avoiding contamination of scientific photometric observations by out-of-field stray-light of these sources.  相似文献   

Verification of an ENSO-Based Long-Range Prediction of Anomalous Weather Conditions During the Vancouver 2010 Olympics and Paralympics     

Ruping Mo  Paul I. Joe  Chris Doyle  Paul H. Whitfield 《Pure and Applied Geophysics》2014,171(1-2):323-336

A brief review of the anomalous weather conditions during the Vancouver 2010 Winter Olympic and Paralympic Games and the efforts to predict these anomalies based on some preceding El Niño–Southern Oscillation (ENSO) signals are presented. It is shown that the Olympic Games were held under extraordinarily warm conditions in February 2010, with monthly mean temperature anomalies of +2.2 °C in Vancouver and +2.8 °C in Whistler, ranking respectively as the highest and the second highest in the past 30 years (1981–2010). The warm conditions continued, but became less anomalous, in March 2010 for the Paralympic Games. While the precipitation amounts in the area remained near normal through this winter, the lack of snow due to warm conditions created numerous media headlines and practical problems for the alpine competitions. A statistical model was developed on the premise that February and March temperatures in the Vancouver area could be predicted using an ENSO signal with considerable lead time. This model successfully predicted the warmer-than-normal, lower-snowfall conditions for the Vancouver 2010 Winter Olympics and Paralympics.  相似文献   

Long-Period Oscillations in Polar Plumes as Observed by cds on Soho     

D. Banerjee  E. O'Shea  J.G. Doyle 《Solar physics》2000,196(1):63-78

We examine spectral time series of the transition region line Ov 629Å, observed with the Coronal Diagnostic Spectrometer (CDS) on the SOHO spacecraft in July 1997. Both Fourier and wavelet transforms have been applied independently to the analysis of plume oscillations in order to find the most reliable periods. The wavelet analysis allows us to derive the duration as well as the periods of the oscillations. Our observations indicate the presence of compressional waves with periods of 10–25 min. We have also detected a 11±1 min periodicity in the network regions of the north polar coronal hole. The waves are produced in short bursts with coherence times of about 30 min. We interpret these oscillations as outward propagating slow magneto-acoustic waves, which may contribute significantly to the heating of the lower corona by compressive dissipation and which may also provide enough energy flux for the acceleration of the fast solar wind. The data support the idea that the same driver is responsible for the network and plume oscillations with the network providing the magnetic channel through which the waves propagate upwards from the lower atmosphere to the plumes.  相似文献