“Scaling-up” fire spread on wood cribs to predict a largescale travelling fire test using CFD

Simulation-based approaches for characterising the fire behaviour of travelling fires in large compartments are a potentially valuable complement to experimental studies, providing useful insights on evolving boundary conditions for structural response. They are attractive in reduced costs and the possibility of carrying out systematic parametric studies free from some of the experimental uncertainties, but sufficiently general models have not been previously demonstrated. Here, we explore the potential for “scaling-up” a “stick-by-stick” CFD model which had been carefully calibrated against the results of experiments on an isolated crib, of 2.8 m diameter, to a uniformly distributed fuel bed of extent 4.2 × 14.0 m located within an open compartment 9 × 15 m in plan, with an internal height of 2.9 m. The results in terms of the fire spread and burn out predictions are very encouraging, and the heat release rate evolution is also consistent with the experimental value. There are some discrepancies in predicted gas phase temperatures, nevertheless, such discrepancies with this aspect of the model are unlikely to have any great significance in the prediction of fire spread on a horizontally orientated flat fuel bed, which is the prime interest of the current work. Thus, the established “numerical simulator” looks to have good potential as a tool to explore and characterise the behaviour of travelling fires subject to different compartment boundary conditions

AUTOMATED ELLIPSOMETER AND THE LIKE SYSTEMS

Systems and methodology for orienting the tip/tilt and vertical height of samples, preferably automated, as applied in ellipsometer and the like systems

AUTOMATED ELLIPSOMETER AND THE LIKE SYSTEMS

Systems and methodology for orienting the tip/tilt ad vertical height of samples, preferably automated, as applied in ellipsometer and the like system

FLYING MOBILE ON-BOARD ELLIPSOMETER, POLARIMETER, REFLECTOMETER AND THE LIKE SYSTEMS

A substantially self-contained “on-boar ” material system investigation system functionally mounted on a three dimen sional locational system to enable positioning at desired locations on, and distances from, the surface of a large sample, including the capability to easily and conveniently change the angle-of-incidence of a beam of electromagnetic radiation onto a sample surface

FLYING MOBILE ON-BOARD ELLIPSOMETER, POLARIMETER, REFLECTOMETER AND THE LIKE SYSTEMS

A substantially self-contained on-board material system investigation system for effecting relative translational and rotational motion between a source and detector of electromagnetic radiation and a sample, which system is functionally mounted on a three-dimensional locational system to enable positioning at desired locations on, and distances from, the surface of a sample, including the capability to easily and conveniently effect rotation and/or to change the angle-of-incidence of a beam of electromagnetic radiation onto a sample surface and/or to provide gas flow confined in a mini-chamber near the surface of a sample, at a location at which a beam having UV, VUV, IR and/or NIR wavelengths of electromagnetic radiation is caused to be impinged thereupon

ASPECTS OF PRODUCING, DIRECTING, CONDITIONING, IMPINGING AND DETECTING SPECTROSCOPIC ELECTROMAGNETIC RADIATION FROM SMALL SPOTS ON SAMPLES

Sytems and mehtods for providing and enhancing electromagnetic radiation beam radail energy homogeneity and intensity vs. wavelength content, for reliably directing electromagnetic radiation emitted by a source thereof in a common direction, for achromatically reducing spot size on a sample (eg. liquid cavity containing lenses and low aberration 1:1 imaging systems modified to perform as spatial filters), and for directing directing different wavelengths into different detectors, in ellipsometer, polarizer or the like systems

SYSTEM FOR AND METHOD OF INVESTIGATING THE EXACT SAME POINT ON A SAMPLE SUBSTRATE WITH MULTIPLE WAVELENGTHS

Disclosed are system for and method of analyzing a sample at substantially the exact same small spot point on a sample with a plurality of wavelengths

A Statistical Analysis of the SOT-Hinode Observations of Solar Spicules and their Wave-like Behavior

We consider a first important parameter of spicules as observed above the solar visible limb: their apparent diameter as a function of the height above the limb which determines their aspect ratio and leads to the discussion of their magnetic origin using the flux tube approximation. We found that indeed spicules show a whole range of diameters, including unresolved "interacting spicules" (I-S), depending of the definition chosen to characterize this ubiquitous dynamical phenomenon occurring into a low coronal surrounding. 1-D Fourier amplitude spectra (AS) made at different heights above the limb are shown for the first time. A definite signature in the 0.18 to 0.25 Mm range exists, corresponding to the occurrence of the newly discovered type II spicules and, even more impressively, large Fourier amplitudes are observed in the 0.3 to the 1.2 Mm range of diameters and spacing, in rough agreement with what historical works were reporting. Additionally, some statistically significant behavior, based on AS computed for different heights above the limb, is discussed. "Time slice or x-t diagrams" revealing the dynamical behavior of spicules are also analyzed. They show that most of spicules have multiple structures (similarly to the doublet spicules) and they show impressive transverse periodic fluctuations which were interpreted as upward kink or Alfven waves. Evidence of the helical motion in spicules is now well evidenced, the typical periods of the apparent oscillation being around 120 sec. A fine analysis of the time-slice diagram as a function of the effective heights shows an interesting new feature near the 2 Mm height. We speculate on the interpretation of this feature as being a result of the dynamical specificities of the spicule helical motion as seen in these unprecedented high resolution HCaII line emission time series.Comment: 21 pages, 8 figurs, 1 tabl

Observed and expected serious adverse event rates in randomised clinical trials for hypertension:An observational study comparing trials which do and do not focus on older people

Background: Representativeness of antihypertensive drug trials is uncertain, as many trials recruit few or no older people. Some trials specifically recruit older participants to address this. Here, we assess the representativeness of trials focusing on older people by comparing the rates of serious adverse events in these trials with the rates in trials of a general adult population (ie, standard trials), and comparing these findings to the rate of hospitalisations and deaths in people with hypertension starting a similar treatment in routine clinical practice. Methods: For this observational study, we identified randomised controlled trials (phase 2/3, 3, or 4) of renin-angiotensin-aldosterone system (RAAS) drugs for hypertension registered from 1999 onwards with ClinicalTrials.gov. Serious adverse events are routinely included in trial reports and are predominantly accounted for by all-cause hospitalisations and deaths. We compared serious adverse event rates in older-people trials (minimum inclusion age ≥60 years) and standard trials (minimum inclusion age <60 years) using Poisson regression models adjusted for trial characteristics (drug type, comparison type, phase, and outcome type). We identified a community cohort of 56 036 adults with hypertension commencing similar drugs to obtain an expected rate of emergency or urgent hospitalisations or deaths, and compared this rate to observed serious adverse event rates in each trial, adjusted for age and sex. For standard trials and for older-people trials, we calculated the standardised ratio of the expected to the observed rate of serious adverse events using Poisson regression models. Findings: We included 110 trials, of which 11 (10%) were older-people trials and 99 (90%) were standard trials. Older-people trials had a higher rate of serious adverse events than did standard trials (median events per person per year 0·18 [IQR 0·12–0·29] vs 0·11 [0·08–0·18]; adjusted incidence rate ratio 1·76 [95% CI 1·01–3·03]). The hospitalisation and death rate in the community for those taking RAAS antihypertensives was much greater than the rate of serious adverse events reported in standard trials (standardised ratio [SR] 4·23, 95% CI 3·51–5·09) and older-people trials (4·76, 2·89–7·86), adjusting for age and sex. The magnitude of risk increase for serious adverse events in community patients taking RAAS did not differ when comparing older-people and standard trials (ratio of SRs 1·13, 95% CI 0·66–1·92). Interpretation: Trials report substantially fewer serious adverse events than expected from rates of hospitalisations and deaths among similar-aged people receiving equivalent treatments in the community. Serious adverse event rates might be a useful metric to assess trial representativeness. Clinicians should be cautious when applying trial recommendations to older people, even when trials focus on older participants. Funding: Wellcome Trust, Medical Research Council