Progressive collapse analysis of composite steel frames subject to fire following earthquake

This paper presents three-dimensional progressive collapse analyses of composite steel frames exposed to fire following earthquake. The scenarios of heating columns located in various different fire compartments (internal, edge and corner bay) are first studied to investigate load redistribution paths and members’ interactions within the composite frame. The results show that the loads previously supported by the heated columns are redistributed to adjacent columns along two horizontal directions, a phenomenon which cannot be captured in a 2D model. Then, the 3D model is adopted to investigate the effect of residual deformation after an earthquake on the progressive collapse behaviour of the composite building. It is found that neither the load redistribution path nor the fire resistance of the building is considerably affected by the residual deformation. A series of progressive collapse analyses subjected to travelling fires resulting from fire compartment damage is also performed. It is concluded that the survival of the building can be greatly affected by the spatial nature of the travelling fire as well as the inter-zone time delay

SCUBA - A submillimetre camera operating on the James Clerk Maxwell Telescope

The Submillimetre Common-User Bolometer Array (SCUBA) is one of a new generation of cameras designed to operate in the submillimetre waveband. The instrument has a wide wavelength range covering all the atmospheric transmission windows between 300 and 2000 microns. In the heart of the instrument are two arrays of bolometers optimised for the short (350/450 microns) and long (750/850 microns) wavelength ends of the submillimetre spectrum. The two arrays can be used simultaneously, giving a unique dual-wavelength capability, and have a 2.3 arc-minute field of view on the sky. Background-limited performance is achieved by cooling the arrays to below 100 mK. SCUBA has now been in active service for over a year, and has already made substantial breakthroughs in many areas of astronomy. In this paper we present an overview of the performance of SCUBA during the commissioning phase on the James Clerk Maxwell Telescope (JCMT).Comment: 14 pages, 13 figures (1 JPEG), Proc SPIE vol 335

Sustainable treatment of hydrocarbon-contaminated industrial land

Land contamination by petroleum hydrocarbons is a widespread and global environmental pollution issue from recovery and refining of crude oil and the ubiquitous use of hydrocarbons in industrial processes and applications. Sustainable treatment of hydrocarbon-contaminated industrial land was considered with reference to seven published works on contaminated railway land including the track ballast, crude oil wastes and contaminated refinery soils. A methodology was developed to assess the level hydrocarbon contamination of track ballast (Anderson et al., 2000) and in Anderson et al. (2002, 2003) solvent and surfactant cleaning of ballast was investigated and potential environmental impacts of the processes examined. Optimisation of ex situ bioremediation of diesel-contaminated soil (Cunningham & Philp, 2000) demonstrated the efficacy of the addition of microorganisms (bioaugmentation) to enhance diesel biodegradation rates at field pilot scale. This work motivated a further study that examined a novel aeration approach incorporating ventilator turbines (cowls) for soil biopiles (Li et al., 2004). An optimised ex situ bioremediation for crude oil wastes was developed in Kuyukina et al. (2003) which demonstrated the efficacy of bioaugmentation and the application of biosurfactants. The final study investigated the potential application of biosurfactants to in situ remediation (Kuyukina et al., 2005) in laboratory soil columns contaminated with crude oil. The collected works are informative to those seeking to remediate hydrocarbon-contaminated industrial land and the sustainability of the approaches was considered

ELT instrumentation for seeing-limited and AO-corrected observations: A comparison

The next generation of large ground-based optical and infrared telescopes will provide new challenges for designers of astronomical instrumentation. The varied science cases for these extremely large telescopes (ELTs) require a large range of angular resolutions, from near diffraction-limited performance via correction of atmospheric turbulence using adaptive optics (AO), to seeing-limited observations. Moreover, the scientific output of the telescopes must also be optimized with the consideration that, with current technology, AO is relatively ineffective at visible wavelengths, and that atmospheric conditions will often preclude high-performance AO. This paper explores some of the issues that arise when designing ELT instrumentation that operates across a range of angular resolutions and wavelengths. We show that instruments designed for seeing-limited or seeing-enhanced observations have particular challenges in terms of size and mass, while diffraction-limited instruments are not as straightforward as might be imagined.Comment: 8 pages, to appear in the SPIE proceedings "ELTs: Which Wavelengths?", from the Lund Symposium on occasion of Arne Ardeberg's retiremen

Hewers of Wood and Drawers of Water: English Subaltern Education from the Charity Schools to the Neoliberal Meritocracy of Widening Participation

British educational ideas and policies towards working-class and minority youth show continuous preoccupations with social status and preparation for labour. In examining this, we link educational discourses and practices in England from the Charity Schools to the contemporary higher education policy Widening Participation (WP). We argue that WP is heir to successive educational programmes that explicitly fit poor and marginalised youth to labour and, contrary to its asserted aims, legitimates social and economic hierarchies. Using major government reports, promotional narratives and data on university expansion and tuition fees, we argue that the ‘disadvantaged student’ in WP is a currency for higher education institutions and student debt is the price of a ticket to ‘success’ within an imagined neoliberal meritocracy. The novelty is that whereas in the past, the costs of subaltern education were covered by philanthropy, today’s ‘disadvantaged students’ indebt themselves to maintain their positions in society

A Maximum Eigenvalue Approximation for Crack-Sizing Using Ultrasonic Arrays

Ultrasonic phased array systems are becoming increasingly popular as tools for the inspection of safety-critical structures with in the non-destructive testing industry. The datasets captured by these arrays can be used to image the internal microstructure of individual components, all owing the location and nature of any defects to be deduced. Unfortunately, many of the current imaging algorithms require an arbitrary threshold at which the defect measurements can be taken and this aspect of subjectivity can lead to varying characterisations of a flaw between different operators. This paper puts forward an objective approach based on the Kirchoff scattering model and the approximation of the resulting scattering matrices by Toeplitz matrices. A mathematical expression relating the crack size to the maximum eigenvalue of the associated scattering matrix is thus derived. The formula is analysed numerically to assess its sensitivity to the system parameters and it is shown that the method is most effective for sizing defects that are commensurate with the wavelength of the ultrasonic wave (or just smaller than. The method is applied to simulated FMC data arising from finite element calculations where the crack length to wavelength ratios range between 0.6 and 1.8. The recovered objective crack size exhibits an error of 12%

The detection of flaws in austenitic welds using the decomposition of the time reversal operator

The non-destructive testing of austenitic welds using ultrasound plays an important role in the assessment of the structural integrity of safety critical structures. The internal microstructure of these welds is highly scattering and can lead to the obscuration of defects when investigated by traditional imaging algorithms. This paper proposes an alternative objective method for the detection of flaws embedded in austenitic welds based on the singular value decomposition of the time-frequency domain response matrices. The distribution of the singular values is examined in the cases where a flaw exists and where there is no flaw present. A lower threshold on the singular values, specific to austenitic welds, is derived which, when exceeded, indicates the presence of a flaw. The detection criterion is successfully implemented on both synthetic and experimental data. The datasets arising from welds containing a flaw, are further interrogated using the decomposition of the time reversal operator (DORT) method and the total focussing method (TFM) and it is shown that images constructed via the DORT algorithm typically exhibit a higher signal to noise ratio than those constructed by the TFM algorithm

Lobeline antagonizes the discriminative stimulus properties of cocaine

Abstract only availableLobeline has high affinity for nicotinic acetylcholine receptors and inhibits the function of vesicular and plasmalemmal monoamine transporters. Moreover, lobeline has been shown to alter the neurochemical and behavioral effects of psychostimulants. In drug discrimination studies, lobeline generalized to cocaine and diminished the stimulus properties of methamphetamine. The present study determined the effect of lobeline, nicotine, mecamylamine and hexamethonium on the discriminative stimulus properties of low doses of cocaine (1.6 or 5.0 mg/kg) or d-amphetamine (0.3 mg/kg) in rats, using a standard two-lever drug discrimination procedure for food reinforcement. Nicotine partially generalized to amphetamine and fully generalized to cocaine, although the discriminative stimulus properties of cocaine and amphetamine were not altered by mecamylamine or hexamethonium. In contrast, lobeline fully generalized to cocaine, but did not generalize to amphetamine. In antagonism tests, lobeline doses that did not generalize to cocaine decreased responding on the cocaine-paired levers. Surprisingly, lobeline did not alter the discriminative stimulus properties of amphetamine. This research further supports the supposition that nicotine, cocaine and amphetamine produce similar, but distinct subjective states. Furthermore, the present findings suggest that lobeline has a complex mechanism of action to disrupt the behavioral effects of drugs of abuse.Life Sciences Undergraduate Research Opportunity Progra