Submerged cylinder wave energy device: theory and experiment     

D.V. Evans  D.C. Jeffrey  S.H. Salter  J.R.M. Taylor 《Applied Ocean Research》1979,1(1):3-12

Linearized water wave theory is used to show that a submerged long circular cylinder suitably constrained by springs and dampers to make small harmonic oscillations, can be extremely efficient in absorbing the energy in an incident regular wave whose crests are parallel to the axis of the cylinder. Experimental results are described which confirm the theory for small amplitude waves and which suggest that the device can still be fairly efficient in waves of moderate amplitude.  相似文献   

驱动重联过程中等离子体团的聚合          下载免费PDF全文

金曙平  师立勤 《地球物理学报》1994,37(1):1-9

本文对驱动重联过程作了二维可压缩磁流体动力学模拟．对于长的计算域（１：４），在持续入流的作用下形成了双重磁岛结构，这些磁岛在向外运动的过程中不断靠近，逐渐聚合成为一个大的等离子体团，并继续向外运动．这说明在地球磁层顶和磁尾所观测到的大尺度磁结构，很可能是在驱动重联过程中，由较小的等离子体团聚合后形成的．并初步揭示了在空间等离子体中，磁岛的聚合过程难以直接观测的动力学原因．  相似文献   

Holistic environmental assessment and offshore oil field exploration and production     

Salter E  Ford J 《Marine pollution bulletin》2001,42(1):45-58

According to UK Government surveys, concern for the environment is growing. Environmental regulation of the industry is becoming wider in its scope and tougher in its implementation. Various techniques are available to assess how the industry can drive down its environmental impact and comply with environmental regulation. Environmental Assessments (EA) required by European law do not cover the whole life cycle of the project that they are analysing. Life Cycle Analysis (LCA) was developed to assess the environmental loadings of a product, process or activity over its entire life cycle. It was the first technique used in environmental analysis that adopted what was described as a holistic approach. It fails this approach by not assessing accidental emissions or environmental impacts other than those that are direct. Cost Benefit Analysis (CBA) offers the opportunity to value environmental effects and appraise a project on the basis of costs and benefits. Not all environmental effects can be valued and of those that can there is considerable uncertainty in their valuation and occurrence. CBA cannot satisfactorily measure the total environmental risk of a project. Consequently there is a need for a technique that overcomes the failures of project-level EA, LCA and CBA, and assesses total environmental risk. Many organizations such as, the British Medical Association, the European Oilfield Speciality Chemicals Association, the Royal Ministry of Petroleum and Energy (Norway) and Shell Expro now recognize that a holistic approach is an integral part of assessing total risk. The Brent SPAR case study highlights the interdisciplinary nature required of any environmental analysis. Holistic Environmental Assessment is recommended as such an environmental analysis.  相似文献   

Polarization observations of the radio cores of AGN — I. A sample of quasars     

D. J. Saikia  G. F. Holmes  A. R. Kulkarni  C. J. Salter  & S. T. Garrington 《Monthly notices of the Royal Astronomical Society》1998,298(3):877-887

We present total-intensity and linear-polarization observations at a single epoch for a sample of 11 quasars and one BL Lac object. The data were taken with the VLA A array at λλ 20, 18, 6 and 2 cm. We examine the variation of the degree of polarization, p , and polarization position angle, PA, with wavelength, and attempt to determine the rotation measure, RM, of the cores in these sources. The degree of polarization does not exhibit any systematic variation with wavelength, the median values ranging from 2.3 to 3.5 per cent at the different wavelengths. The variation of PA with λ² is not linear over the entire wavelength range. However, for most sources the λλ 20-, 18- and 6-cm PAs do follow such a linear relationship, yielding a median |RM| of about 15 rad m⁻². In contrast, the λλ 6- and 2-cm observations give a median |RM| of about 129 rad m⁻². The long-wavelength emission is likely to originate from a spatially different part of the milliarcsec-scale jet from the λ 2-cm emission, which could turn over at a higher frequency and is likely to be more compact and located closer to the quasar nucleus. We have attempted to obtain linear fits over the entire wavelength range allowing for n  π ambiguities in the PAs, but the fits are not statistically significant. The low values of RM for these core-dominated sources suggest that either the radio emission from the jet intercepts few of the emission-line clouds and their confining medium, or the clouds have a small filling factor and are possibly magnetically confined.  相似文献   

Identifying and removing structural biases in climate models with history matching     

Williamson  Daniel  Blaker  Adam T.  Hampton  Charlotte  Salter  James 《Climate Dynamics》2015,45(5-6):1299-1324

Climate Dynamics - We describe the method of history matching, a method currently used to help quantify parametric uncertainty in climate models, and argue for its use in identifying and removing...  相似文献   

Further observations of radio sources from the BG survey. II. Mainly extragalactic     

F. Mantovani  M. Nanni  C. J. Salter  P. Tomasi 《Journal of Astrophysics and Astronomy》1982,3(3):335-350

New observations of six fields from the low galactic latitude BG survey are presented. The radio sources within each of these fields appear to be of a predominantly extragalactic nature. However, one object is in close positional proximity to the pulsar 1922 + 20 and the possibility of their association is considered. The extended source BGE 0323 + 65 is shown to be unlikely to exist.  相似文献   

Cycling excursion to the Chiltern Hills: Saturday,July 8th, 1899     

H.J. Osborne White  A.E. Salter 《Proceedings of the Geologists' Association. Geologists' Association》1899,16(5):251-254

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Pebbly and other gravels in Southern England     

A.E. Salter 《Proceedings of the Geologists' Association. Geologists' Association》1898,15(7):264-286

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Excursion to Gravesend: Saturday,September 10th, 1898     

G.E. Dibley  A.E. Salter 《Proceedings of the Geologists' Association. Geologists' Association》1898,15(10):463-464

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Delay time optimization in blasting operations for mitigating the vibration-effects on final pit walls' stability     

X.Z. Shi  SH.R Chen 《Soil Dynamics and Earthquake Engineering》2011

Blasting induced vibration is one of the fundamental problems in the open-pit mines and intense vibration can cause critical damage to structures and plants nearby the open-pit mines, especially to the final pit wall's stability. It is very important to study how to control vibration induced by blasting in the mitigation of negative effects of blasting in open-pit mines. This study aims to examine the propagation of blasting induced ground vibrations and find the feasible approaches to reduce the harmful effects of vibrations induced by blasting on the final pit wall's stability. For this purpose, a series of field experiments were conducted in XinQiao Mining Co. Ltd. Sixty-six events and the blasting parameters of these shots were carefully recorded. During the statistical analysis of the collected data, the predictor equation proposed by the United States Bureau of Mines (USBM) was used to establish a relationship between the Peak Particle Velocity (PPV) and the Scaled Distance (SD) factor. The relationship between PPV and SD was determined and proposed to be used in this open-pit mine. Control of maximum charge amount per delay and the selection optimum interval time to reduce the intensity of vibration by waveform interference were applied in practice. Based on the field experiments, we can determine the maximum charge amount per delay and 15 ms delay were proposed to be used in this site, and a decrease in vibration of 24.5% was obtained.  相似文献