67,138 research outputs found
Delivering sustainable buildings in retail construction
Session: Sustainability: Theory and Design The article can be viewed at: http://www.arcom.ac.uk/-docs/proceedings/ar2012-1455-1465_Dangana_Pan_Goodhew.pdfThe demand for high performance 'green' or 'sustainable' buildings is becoming increasingly important in the retail industry. Large construction companies in this sector have started to show leadership by working with their customers and supply chains towards sustainability in both products and operations. However, it remains associated risks be minimised, in order to add value and differentiate the output of retail construction. This paper reviews the practice of sustainable buildings within the context of retail construction, and also explores how the UK mainstream retail sector is currently addressing the challenges of sustainable retail buildings. The arguments are informed by a combination of literature review, a desk study of sustainability strategies of large client organisations and construction companies, and a case study with a leading construction company in the UK. The results demonstrate that businesses can benefit from embracing a sustainable approach while they need to adapt their business models to the rapidly changing environment. A demand-driven sustainability agenda is called for in the UK retail sector. The results also provide the basis for an in-depth, longitudinal case study to develop a framework to optimize process, energy and carbon efficiency in retail construction using sustainable technology. Such a framework should provide a sustainable technology model for retail customers to realize the full benefits of sustainable buildings and also assist construction companies and their professional advisors deliver green buildings more efficiently in the future
A Decision Making System for Selecting Sustainable Technologies for Retail Buildings
CIB Publication 382: Selected papers presented at the CIB World Building Congres Construction and Society, Brisbane 5-9 May 2013 Papers from the Designated Session TG66 - Energy and the Built EnvironmentThe implementation of sustainable technologies can improve the energy and carbon efficiency of existing retail buildings. However, the selection of an appropriate sustainable technology is a complex task due to the large number of technological alternatives and decision criteria that need to be considered. Also, there exist series of uncertainties that are associated with the use of sustainable technologies, but have to be evaluated to achieve realistic and transparent results. The selection of sustainable technology is therefore most challenging. An earlier study was conducted with UK experienced practitioners including clients/developers, engineers, contractors and suppliers to identify the drivers and barriers for the use of sustainable technologies in UK retail construction. One major barrier identified from the study was the lack of a decision making tool, highlighted by both construction professionals and stakeholders in the retail industry. The large number of alternatives and potential solutions require a decision support method to be implemented. Information data on the economic variables, energy performance and impact on the environment of these systems is presently affected by vagueness and lack of knowledge. To deal with this high level of complexity and uncertainty an evaluation support approach is needed. This paper aims to develop a decision making framework to assist both retailers and construction professionals to define and evaluate the selection of sustainable technological options for delivering retail buildings. The research was carried out through a combination of a critical literature review and a survey-based study using expert opinions of retailers and contractors. The developed framework of decision criteria should provide a sustainable technology model to assist both construction professionals and stakeholders in the retail industry to systematically and effectively select the most appropriate technology. This approach should make the decision progression more transparent and facilitate sustainable development of retail buildings in achieving the carbon targets set by the UK and other governments
The development of a three-dimensional partially elliptic flow computer program for combustor research
A three dimensional, partially elliptic, computer program was developed. Without requiring three dimensional computer storage locations for all flow variables, the partially elliptic program is capable of predicting three dimensional combustor flow fields with large downstream effects. The program requires only slight increase of computer storage over the parabolic flow program from which it was developed. A finite difference formulation for a three dimensional, fully elliptic, turbulent, reacting, flow field was derived. Because of the negligible diffusion effects in the main flow direction in a supersonic combustor, the set of finite-difference equations can be reduced to a partially elliptic form. Only the pressure field was governed by an elliptic equation and requires three dimensional storage; all other dependent variables are governed by parabolic equations. A numerical procedure which combines a marching integration scheme with an iterative scheme for solving the elliptic pressure was adopted
Swapping path-spin intraparticle entanglement onto spin-spin interparticle entanglement
Based on a scheme that produces an entanglement between the spin and the path
variables of a single spin-1/2 particle (qubit) using a beam-splitter and a
spin-flipper, we formulate a procedure for transferring this intraparticle
hybrid entanglement to an interparticle entanglement between the spin variables
of two other spatially separated spin-1/2 particles which never interact with
each other during the entire process. This procedure of entanglement swapping
is accomplished by a Mach-Zehnder setup in conjunction with the Stern-Gerlach
measuring device, using suitable unitary operations. The proposed protocol,
thus, enables the use of intraparticle entanglement as a resource - a feature
that has remained unexplored.Comment: 5 pages, 1 Figur
The induced representations of Brauer algebra and the Clebsch-Gordan coefficients of SO(n)
Induced representations of Brauer algebra from with are discussed. The induction coefficients
(IDCs) or the outer-product reduction coefficients (ORCs) of with up to a normalization factor are
derived by using the linear equation method. Weyl tableaus for the
corresponding Gel'fand basis of SO(n) are defined. The assimilation method for
obtaining CG coefficients of SO(n) in the Gel'fand basis for no modification
rule involved couplings from IDCs of Brauer algebra are proposed. Some
isoscalar factors of for the resulting irrep
with
$\sum\limits_{i=1}^{4}\lambda_{i}\leq .Comment: 48 pages latex, submitted to Journal of Phys.
Clerocidin selectively modifies the gyrase-DNA gate to induce irreversible and reversible DNA damage
Clerocidin (CL), a microbial diterpenoid, reacts with DNA via its epoxide group and stimulates DNA cleavage by type II DNA topoisomerases. The molecular basis of CL action is poorly understood. We establish by genetic means that CL targets DNA gyrase in the gram-positive bacterium Streptococcus pneumoniae, and promotes gyrase-dependent single- and double-stranded DNA cleavage in vitro. CL-stimulated DNA breakage exhibited a strong preference for guanine preceding the scission site (-1 position). Mutagenesis of -1 guanines to A, C or T abrogated CL cleavage at a strong pBR322 site. Surprisingly, for double-strand breaks, scission on one strand consistently involved a modified (piperidine-labile) guanine and was not reversed by heat, salt or EDTA, whereas complementary strand scission occurred at a piperidine-stable -1 nt and was reversed by EDTA. CL did not induce cleavage by a mutant gyrase (GyrA G79A) identified here in CL-resistant pneumococci. Indeed, mutations at G79 and at the neighbouring S81 residue in the GyrA breakage-reunion domain discriminated poisoning by CL from that of antibacterial quinolones. The results suggest a novel mechanism of enzyme inhibition in which the -1 nt at the gyrase-DNA gate exhibit different CL reactivities to produce both irreversible and reversible DNA damage
The impact of a wave farm on large scale sediment transport
This study investigates the interactions of waves and tides at a wave farm in the southwest of England, in particular their effects on radiation stress, bottom stress, and consequently on the sediment transport and the coast adjacent to the wave-farm (the Wave Hub). In this study, an integrated complex numerical modelling system is setup at the Wave Hub site and is used to compute the wave and current fields by taking into account the wave-current interaction, as well as the sediment transport. Results show that tidal elevation and tidal currents have a significant effect on the wave height and direction predictions; tidal forcing and wind waves have a significant effect on the bed shear-stress, relevant to sediment transport; waves via radiation stresses have an important effect on the longshore and cross-shore velocity components, particularly during the spring tides. Waves can impact on bottom boundary layer and mixing in the water column. The results highlight the importance of the interactions between waves and tides when modelling coastal morphology with presence of wave energy devices
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Improving Precipitation Estimation Using Convolutional Neural Network
Precipitation process is generally considered to be poorly represented in numerical weather/climate models. Statistical downscaling (SD) methods, which relate precipitation with model resolved dynamics, often provide more accurate precipitation estimates compared to model's raw precipitation products. We introduce the convolutional neural network model to foster this aspect of SD for daily precipitation prediction. Specifically, we restrict the predictors to the variables that are directly resolved by discretizing the atmospheric dynamics equations. In this sense, our model works as an alternative to the existing precipitation-related parameterization schemes for numerical precipitation estimation. We train the model to learn precipitation-related dynamical features from the surrounding dynamical fields by optimizing a hierarchical set of spatial convolution kernels. We test the model at 14 geogrid points across the contiguous United States. Results show that provided with enough data, precipitation estimates from the convolutional neural network model outperform the reanalysis precipitation products, as well as SD products using linear regression, nearest neighbor, random forest, or fully connected deep neural network. Evaluation for the test set suggests that the improvements can be seamlessly transferred to numerical weather modeling for improving precipitation prediction. Based on the default network, we examine the impact of the network architectures on model performance. Also, we offer simple visualization and analyzing approaches to interpret the models and their results. Our study contributes to the following two aspects: First, we offer a novel approach to enhance numerical precipitation estimation; second, the proposed model provides important implications for improving precipitation-related parameterization schemes using a data-driven approach
Embedding impedance approximations in the analysis of SIS mixers
Future millimeter-wave radio astronomy instruments will use arrays of many SIS receivers, either as focal plane arrays on individual radio telescopes, or as individual receivers on the many antennas of radio interferometers. Such applications will require broadband integrated mixers without mechanical tuners. To produce such mixers, it will be necessary to improve present mixer design techniques, most of which use the three-frequency approximation to Tucker's quantum mixer theory. This paper examines the adequacy of three approximations to Tucker's theory: (1) the usual three-frequency approximation which assumes a sinusoidal LO voltage at the junction, and a short-circuit at all frequencies above the upper sideband; (2) a five-frequency approximation which allows two LO voltage harmonics and five small-signal sidebands; and (3) a quasi five-frequency approximation in which five small-signal sidebands are allowed, but the LO voltage is assumed sinusoidal. These are compared with a full harmonic-Newton solution of Tucker's equations, including eight LO harmonics and their corresponding sidebands, for realistic SIS mixer circuits. It is shown that the accuracy of the three approximations depends strongly on the value of omega R(sub N)C for the SIS junctions used. For large omega R(sub N)C, all three approximations approach the eight-harmonic solution. For omega R(sub N)C values in the range 0.5 to 10, the range of most practical interest, the quasi five-frequency approximation is a considerable improvement over the three-frequency approximation, and should be suitable for much design work. For the realistic SIS mixers considered here, the five-frequency approximation gives results very close to those of the eight-harmonic solution. Use of these approximations, where appropriate, considerably reduces the computational effort needed to analyze an SIS mixer, and allows the design and optimization of mixers using a personal computer
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