Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

Fatigue and creep in wood based panel products

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN004517 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Effect of Two Relative Humidity Environments on the Performance Properties of MDF, OSB and Chipboard. Part 1. MOR, MOE and fatigue life performance

The static strength, stiffness and fatigue life of MDF, OSB and chipboard have been measured in a 65%RH environment and a 85%RH environment. Chipboard is commonly utilised as a flooring material and OSB is also used in structural applications, for example floor decking and webs of I-beams. The mean static strengths of MDF, OSB and chipboard at 65%RH were 47.9 MPa, 27.9 MPa and 21.0Mpa, respectively, compared with 34.59 MPa, 21.70 MPa and 10.61 MPa at 85%RH. However, MDF has mostly been used in non-structural applications, such as furniture, so its resistance to fatigue loads as a structural panel is of considerable interest. In a 65%RH environment dynamic modulus values showed that whilst MDF and chipboard exhibit similar stiffness values (4 GPa), OSB is approximately 50% stiffer. However, at 85%RH MDF was the stiffest of the three materials, followed by OSB and chipboard. The fatigue life performance of all three panel products was markedly lower at 85%RH compared with 65%RH. Overall, the high RH environment had a noticeably detrimental effect on the MOE (modulus of elasticity), MOR (modulus of rupture) and fatigue lives of OSB and chipboard. This is attributed to these panels retaining more of the original characteristics of the original wood, i.e. larger particle sizes (flakes/chips) compared with the homogeneous fibrous composition of MDF

Complex interactions in a rapidly changing world: responses of rocky shore communities to recent climate change

Warming of the planet has accelerated in recent years and is predicted to continue overthe next 50 to 100 yr. Evidence of responses to present warming in marine ecosystems include shiftsin the geographic range of species as well as in the composition of pelagic and demersal fish, benthicand intertidal assemblages. Here we provide a review of the changes in geographic distributions andpopulation abundance of species detected on rocky shores of the NE Atlantic over the last 60 yr. Thisperiod encompassed the warm 1950s, a colder period between 1963 and the late 1980s and the recentperiod of accelerating warming to levels above those of the 1950s. The likely consequences of theseresponses are then explored. To do this, a summary of the dynamic balance between grazers,macroalgae and barnacles in structuring mid-shore communities is given before outlining experimentalwork on interactions between key components of rocky shore communities. Modelling andquantitative forecasting were used to predict changes in community composition and dynamics in awarmer world and their consequences for ecosystem functioning discussed. We then identify areasthat need further work before making a case for the use of rocky shore species not just as inexpensiveindicators of change offshore, but as tractable models to explore the direct and indirect effects ofclimate change in marine and coastal ecosystems. We also provide a societal perspective emphasisingthe value of long-term studies in informing adaptation to climate change