1,396 research outputs found

    Contractors Perspective on the Selection of Innovative Sustainable Technologies for Achieving Zero Carbon Retail Buildings

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    The use of innovative sustainable technologies (IST) has been regarded as an effective approach to enhancing energy efficiency and reducing carbon emissions of buildings. However, contractors face significant challenges in the selection of IST. The reported challenges in the literature include: lack of skills and knowledge, uncertainties, risks and the rapid development of a large number of technological alternatives and decision criteria. The selection process emerges as a multi-attribute, value-based task that includes both qualitative and quantitative factors, which are often assessed with imprecise data and human judgments. This paper aims to establish the decision criteria for the selection of IST for achieving low carbon existing retail buildings with a focus on the main contractor’s perspective. The arguments are informed by the combination of literature review and an in-depth case study with a UK leading contractor. Five broad decision criteria are identified systematically drawing on the contractor’s practice. The established criteria are weighted and ranked using the analytic hierarchy process and expert opinions; with ‘margin opportunity’ being the most important, followed by ‘repeat business’, ‘investment costs’, ‘differentiation’ and then ‘transferability’. The findings should facilitate the integration of various facets of the selection process and stimulate contractors to use IST

    Big Data on Decision Making in Energetic Management of Copper Mining

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    Indexado en: Web of Science; Scopus.It is proposed an analysis of the related variables with the energetic consumption in the process of concentrate of copper; specifically ball mills and SAG. The methodology considers the analysis of great volumes of data, which allows to identify the variables of interest (tonnage, temperature and power) to reach to an improvement plan in the energetic efficiency. The correct processing of the great volumen of data, previous imputation to the null data, not informed and out of range, coming from the milling process of copper, a decision support systems integrated, it allows to obtain clear and on line information for the decision making. As results it is establish that exist correlation between the energetic consumption of the Ball and SAG Mills, regarding the East, West temperature and winding. Nevertheless, it is not observed correlation between the energetic consumption of the Ball Mills and the SAG Mills, regarding to the tonnages of feed of SAG Mill. In consequence, From the experimental design, a similarity of behavior between two groups of different mills was determined in lines process. In addition, it was determined that there is a difference in energy consumption between the mills of the same group. This approach modifies the method presented in [1].(a)http://www.univagora.ro/jour/index.php/ijccc/article/view/2784/106

    Development in Lexicography: From Polyfunctional to Monofunctional Accounting Dictionaries

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    This article describes the theoretical foundation of the accounting dictionaries as well as its practical results. Furthermore, the implementation of the project shows how the constant interaction of lexicographical theory with practical dictionary work over a period of 10 years has led to lexicographical development and adaptation resulting in ongoing adjustments to the dictionaries and their theoretical foundation. This is exemplified by studying the transition from polyfunctional to monofunctional dictionaries in an attempt to provide help in several types of usage situations, typically in communicative situations, e.g. when reading, writing or translating English, Danish or Spanish accounting texts, or cognitive situations, i.e. when users want to know more about accounting matters or accounting language. The article also indicates that the creation of this project connects e-lexicography with the knowledge-based economy. Lexicographers work in the cloud being physically thousands of kilometres away; they work with experts in accounting, databases and the Internet with the aim of constructing and updating a high-quality tool with relatively low information costs for users. Finally, this article shows that the future of lexicography rests on designing, constructing, and updating information tools that take into consideration not only the true nature of lexicography but also the possibilities of the Internet and its technologies, as advocates of the Function Theory of Lexicography do on a regular basis.Keywords: specialized lexicography, function theory, polyfunctional dictionary, monofunctional dictionary, accounting dictionaries, information tools, lexicographical information costs, online dictionary, electronic lexicography, internet, meaning, writing, translation, knowledge, danish, english, spanis

    Correlation functions in the non-relativistic AdS/CFT correspondence

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    We study the correlation functions of scalar operators in the theory defined as the holographic dual of the Schroedinger background with dynamical exponent z=2 at zero temperature and zero chemical potential. We offer a closed expression of the correlation functions at tree level in terms of Fourier transforms of the corresponding n-point functions computed from pure AdS in the lightcone frame. At the loop level this mapping does not hold and one has to use the full Schroedinger background, after proper regularization. We explicitly compute the 3-point function comparing it with the specific 3-point function of the non-relativistic theory of cold atoms at unitarity. We find agreement of both 3-point functions, including the part not fixed by the symmetry, up to an overall normalization constant.Comment: 32 pages, 7 figures; v2: typos corrected, references added and additional discussion about the case of compact number-direction, includes new appendix with the computations of the 2 and 3 point function for the compact number-direction case. The general results remain the same. Version published in Phys.Rev.

    Energy saving behaviours among social housing tenants: Exploring the relationship with dwelling characteristics, monetary concerns, and psychological motivations

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    Increasing our understanding of the factors that influence energy saving behaviour could help in the development of more effective energy saving interventions. This paper describes the first phase of the EnerGAware project which aims to develop a serious game for social housing tenants in the UK. A survey was conducted to inform the design of the game, which investigated the relationship between psychological factors, context-specific factors (i.e. dwelling characteristics and monetary concerns), and energy saving behaviours. In total, 537 households completed a postal survey, with a response rate of 19.4%. The results showed that experiencing difficulty in keeping the home comfortably warm in winter related to behaviour. In particular, concerns about the affordability of heating seemed to be related to more frequent heating-related energy saving behaviours. Experiencing issues with overheating, damp, mould or condensation – and general concerns about energy bills, did not relate to energy saving behaviours. Overall, the psychological factors measured in the study related more strongly to energy saving behaviours; especially the ability to imagine energy use and strong social norms had a positive relationship with energy saving behaviour. The implications of the findings for the design of the serious game are discussed. Thus, the study uses a combined approach examining psychological and contextual factors to illustrate how important behavioural motivators relevant to a specific group of householders can be included in the design of an intervention

    High-pressure study of substrate material ScAlMgO4

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    We report on the structural properties of ScAlMgO4 studied under quasi-hydrostatic pressure using synchrotron high-pressure x-ray diffraction up to 40 GPa. We also report on single-crystal studies of ScAlMgO4 performed at 300 K and 100 K. We found that the low-pressure phase remains stable up to 24 GPa. At 28 GPa, we detected a reversible phase transformation. The high-pressure phase is assigned to a monoclinic distortion of the low-pressure phase. No additional phase transition is observed up to 40 GPa. In addition, the equation of state, compressibility tensor, and thermal expansion coefficients of ScAlMgO4 are determined. The bulk modulus of ScAlMgO4 is found to be 143(8) GPa, with a strong compressibility anisotropy. For the trigonal low-pressure phase, the compressibility along the c-axis is twice than perpendicular one. A perfect lattice match with ZnO is retained under pressure in the pressure range of stability of wurtzite ZnO.Comment: 22 pages, 5 figures, 4 tables, 24 reference

    High-pressure structural investigation of several zircon-type orthovanadates

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    Room temperature angle-dispersive x-ray diffraction measurements on zircon-type EuVO4, LuVO4, and ScVO4 were performed up to 27 GPa. In the three compounds we found evidence of a pressure-induced structural phase transformation from zircon to a scheelite-type structure. The onset of the transition is near 8 GPa, but the transition is sluggish and the low- and high-pressure phases coexist in a pressure range of about 10 GPa. In EuVO4 and LuVO4 a second transition to a M-fergusonite-type phase was found near 21 GPa. The equations of state for the zircon and scheelite phases are also determined. Among the three studied compounds, we found that ScVO4 is less compressible than EuVO4 and LuVO4, being the most incompressible orthovanadate studied to date. The sequence of structural transitions and compressibilities are discussed in comparison with other zircon-type oxides.Comment: 34 pages, 2 Tables, 11 Figure

    Metal-Metal Cooperation in the Oxidation of a Flapping Platinum Butterfly by Haloforms: Experimental and Theoretical Evidence

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    The model 1-DFT for the butterfly complex [{Pt(CÂżC*)(”-pz)}2] (1; HCÂżC* = 1-(4-(ethoxycarbonyl)phenyl)-3-methyl-1H-imidazol-2-ylidene) shows two minima in the potential energy surface of the ground state in acetone solution: the butterfly-wing-spreading molecules 1-s, (dPt-Pt ˜ 3.20 Å) and the wing-folding molecules 1-f (dPt-Pt = 3.00 Å). Both minima are very close in energy (ÂżG° = 1.7 kcal/mol) and are connected through a transition state, which lies only 1.9 kcal/mol above 1-s and 0.2 kcal/mol above 1-f. These very low barriers support a fast interconversion process, resembling a butterfly flapping, and the presence of both conformers in acetone solution. However, the 1-f ratio is so low that it is undetectable in the excitation and emission spectra of 1 in 2-MeTHF of diluted solutions (10-5 M) at 77 K, while it is seen in more concentrated solutions (10-3 M). In acetone solution, 1 undergoes a [2c, 2e] oxidation by CHX3 (X = Cl, Br) in the sunlight to render the Pt2(III, III) compounds [{Pt(CÂżC*)(”-pz)X)}2] (X = Cl (2-Cl), Br (2-Br)). In concentrated solutions, 1 can react with CHCl3 under blue light to give 2-Cl and with CHBr3 in the dark, the latter rendering the compound [BrPt(CÂżC*)(”-pz)2Pt(CÂżC*)CHBr2] (3-Br) or mixtures of 2-Br and 3-Br if the reaction is performed under an argon atmosphere or in the air, respectively. Mechanistic studies showed that in concentrated solutions the oxidation processes follow a radical mechanism being the MMLCT-based species 1-f, those which trigger the reaction of 1 with CHBr3 and CHCl3. In the ground state (S0f), it promotes the thermal oxidation of 1 by CHBr3 and in the first singlet excited state (S1f) the blue-light-driven photooxidation of 1 by CHCl3. Complexes, 2-Cl, 2-Br, and 3-Br were selectively obtained and fully characterized, showing Pt-Pt distances (ca. 2.6 Å) shorter than that of the starting complex, 1. They are, together with the analogous [{Pt(CÂżC*)(”-pz)I)}2] and [IPt(CÂżC*)(”-pz)2Pt(CÂżC*)CHI2], the only dinuclear metal-metal-bonded PtIII(”-pz)2PtIII compounds reported to date

    STUDY OF SENSITIVITY OF THE PARAMETERS OF A GENETIC ALGORITHM FOR DESIGN OF WATER DISTRIBUTION NETWORKS

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    The Genetic Algorithms (GAs) are a technique of optimization used for water distribution networks design. This work has been made with a modified pseudo genetic algorithm (PGA), whose main variation with a classical GA is a change in the codification of the chromosomes, which is made of numerical form instead of the binary codification. This variation entails a series of special characteristics in the codification and in the definition of the operations of mutation and crossover. Initially, the work displays the results of the PGA on a water network studied in the literature. The results show the kindness of the method. Also is made a statistical analysis of the obtained solutions. This analysis allows verifying the values of mutation and crossing probability more suitable for the proposed method. Finally, in the study of the analyzed water supply networks the concept of reliability in introduced. This concept is essential to understand the validity of the obtained results. The second part, starting with values optimized for the probability of crossing and mutation, the influence of the population size is analyzed in the final solutions on the network of Hanoi, widely studied in the bibliography. The aim is to find the most suitable configuration of the problem, so that good solutions are obtained in the less time

    Emptying operation of water supply networks

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    Recently, emptying processes have been studied in experimental facilities in pipelines, but there is a lack regarding applications in actual pipelines, which permits establishing the risk of collapse because of sub-atmospheric pressure occurrence. This research presents a mathematical model to simulate the emptying process of water supply networks, and the application to a water emptying pipeline with nominal diameter of 1000 mm and 578 m long which is located on the southern of Cartagena, Bolívar Deparment, Colombia. In the application, both pipes and the air valve data manufacturer were considered. The behavior of all hydraulic and thermodynamic variables is considered. Results show that is crucial to know sub-atmospheric pressure values to prevent the collapse of the pipeline. The application of the mathematical model confirms that the hydraulic system is well designed depending on air valve sizes and maneuvering of drain valve. © 2018 by the authors
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