Empirical prediction of traffic noise transmission loss across plenum windows

A parametric study on the traffic noise transmission loss across plenum windows was carried out experimentally in this investigation in an attempt to establish a simple empirical model for predicting this transmission loss. A total of fourteen full scale plenum windows were included in this study. The results of a site mockup measurement were used for model validation. The present model was developed based on the existing plenum chamber theory in which the sound fields inside the plenum window cavities were assumed to make up of a diffracted wave and a reverberant field. Results suggest that both the diffracted and reverberant field inside the plenum window cavities are weaker than those assumed in existing plenum chamber theory. It is found that a model, which assumes frequency-independent diffraction directivity and percentage reverberant field attenuation, gives the best prediction of traffic noise transmission loss. This prediction model is also able to predict site test results with good accurac

Compromising building regulations and user expectations in the design of high-rise domestic kitchens

Purpose ??? The purpose of this paper is to discuss the significance and relevance of social and habitual behaviours of home occupants to the building design process. It argues that introducing quantitative measures such as daylight level alone may not result in a ???healthy and functional??? kitchen without appreciating or factoring-in the impacts of the social roles and user expectations of kitchens in high-rise and compact urban situations.\ud Design/methodology/approach ??? The study investigated three common types of apartment buildings in Hong Kong. Case studies suggested that it is crucial to include in a design process proper considerations of human behaviours byway of preferred approaches andmodes of living, space usage, and weightings of end-user responses that would influence architectural design in a direct and crucial way.\ud Findings ??? The study noted that daylight quality of a kitchen is perceived by most families to be not as important as building control officials and designers thought it would. Instead, it is found that social and cultural factors are more important parameters for users. The study observed that designers rely on physical and quantitative approaches such as daylight factor, window size and window-to-room area ratio to qualify a design solution and ignore the socio-cultural parameters.\ud Originality/value ??? The paper calls for designers and building control officials to incorporate the study of functionality and socio-cultural preferences of users groups in the building design process. The study envisages that an integrated design methodology would enhance the living environment

Interchange Slip-Running Reconnection and Sweeping SEP Beams

We present a new model to explain how particles (solar energetic particles; SEPs), accelerated at a reconnection site that is not magnetically connected to the Earth, could eventually propagate along the well-connected open flux tube. Our model is based on the results of a low-beta resistive magnetohydrodynamics simulation of a three-dimensional line-tied and initially current-free bipole, that is embedded in a non-uniform open potential field. The topology of this configuration is that of an asymmetric coronal null-point, with a closed fan surface and an open outer spine. When driven by slow photospheric shearing motions, field lines, initially fully anchored below the fan dome, reconnect at the null point, and jump to the open magnetic domain. This is the standard interchange mode as sketched and calculated in 2D. The key result in 3D is that, reconnected open field lines located in the vicinity of the outer spine, keep reconnecting continuously, across an open quasi-separatrix layer, as previously identified for non-open-null-point reconnection. The apparent slipping motion of these field lines leads to form an extended narrow magnetic flux tube at high altitude. Because of the slip-running reconnection, we conjecture that if energetic particles would be traveling through, or be accelerated inside, the diffusion region, they would be successively injected along continuously reconnecting field lines that are connected farther and farther from the spine. At the scale of the full Sun, owing to the super-radial expansion of field lines below 3 solar radii, such energetic particles could easily be injected in field lines slipping over significant distances, and could eventually reach the distant flux tube that is well-connected to the Earth

Surveillance of Influenza B Virus Strains Circulating in Malaysia (2002—2006)

Background: The Virology Unit, Institute for Medical Research (IMR), Kuala Lumpur has been designated as the National Influenza Centre since 1968, carrying out influenza surveillance activities for the Ministry of Health Malaysia. These activities are important for preparation of epidemics and pandemics. In the past decade, several outbreaks of influenza B have been reported in this country. Thus, the aims of this study are to evaluate the incidence and to identify the circulating viral strain of influenza type B in Malaysia. Methods: All respiratory specimens received from several sentinel sites from patients presenting with influenza-like illness (ILI) were included in this study. The virus was detected by culture method using Madin Darby Canine Kidney (MDCK) cells with combination of Immunofluorescence (IF) and haemagglutination inhibition (HAI) techniques. Results: From 2002 to 2006 the National Influenza Centre, IMR received a total of 5,463 specimens from patients presenting with ILI. Of these, 220 (4.0%) were found to be positive for Influenza B virus and further analysis showed that there were four major strains circulating in Malaysia during the five years study period. The predominant strain in 2002 was B/Hong Kong/330/2001-like virus, B/Sichuan/379/99-like virus in 2003, B/Shanghai/361/2002- like virus in 2004, B/Hong Kong/330/2001-like virus in 2005 and B/Malaysia/2506/2004-like virus in 2006. Conclusion: The surveillance activities are not only important as an early warning for outbreak preparedness but also important in detecting new strains that can be used in the annual vaccine formulation

Recent Advances in Understanding Particle Acceleration Processes in Solar Flares

We review basic theoretical concepts in particle acceleration, with particular emphasis on processes likely to occur in regions of magnetic reconnection. Several new developments are discussed, including detailed studies of reconnection in three-dimensional magnetic field configurations (e.g., current sheets, collapsing traps, separatrix regions) and stochastic acceleration in a turbulent environment. Fluid, test-particle, and particle-in-cell approaches are used and results compared. While these studies show considerable promise in accounting for the various observational manifestations of solar flares, they are limited by a number of factors, mostly relating to available computational power. Not the least of these issues is the need to explicitly incorporate the electrodynamic feedback of the accelerated particles themselves on the environment in which they are accelerated. A brief prognosis for future advancement is offered.Comment: This is a chapter in a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter