Search results for "Operation"
showing 10 items of 2969 documents
Calculation of miscibility behavior of multinary polymer blends
1996
A method for the calculation of phase diagrams (tie lines and binodal, spinodal, critical points and their stability) based exclusively on the Gibbs energy of mixing, δG, is presented which does not require the calculation of the derivatives with respect to the composition. The method is demonstrated for ternary mixtures of two homopolymers and the corresponding copolymer, and for quaternary and quinternary blends of five polymers exhibiting a closed miscibility gap. The advantages of the presented method become most obvious in the mathematical description of measured phase diagrams, where complex composition dependencies of the interaction parameter are observed.
Liquid–liquid equilibria of 4-methyl-2-pentanone+1-propanol or 2-propanol+water ternary systems: Measurements and correlation at different temperatur…
2014
Abstract In this work, experimental liquid–liquid equilibria data of the systems 4-methyl-2-pentanone + 1-propanol + water and 4-methyl-2-pentanone + 2-propanol + water are presented. The liquid–liquid equilibria of both systems have been measured at 283.2 and 323.2 K. The NRTL and UNIQUAC models were successfully applied to fit the data for both ternary systems. The binodal lines were compared to the values predicted by the UNIFAC-LLE and UNIFAC models. Moreover, the solvent capability of 4-methyl-2-pentanone was checked in order to separate the azeotropic mixtures formed by propanol's and water.
Measurements and correlation of liquid–liquid equilibria of 4-methyl-2-pentanone+ethanol+water and 4-methyl-2-pentanone+n-butanol+water ternary syste…
2012
Abstract In this work, experimental liquid–liquid equilibria data of the systems 4-methyl-2-pentanone + ethanol + water and 4-methyl-2-pentanone + n-butanol + water are presented. The liquid–liquid equilibria of both systems have been measured between 283.2 and 323.2 K. The NRTL and UNIQUAC models were applied to fit the data for both ternary systems. The interaction parameters obtained from both models successfully correlated the equilibrium compositions. The binodal lines were compared to the values predicted by the UNIFAC-LLE and UNIFAC models. Moreover, the solvent capability of 4-methyl-2-pentanone was checked in order to separate these azeotropic mixtures alcohol + water.
The rise of the middle author: Investigating collaboration and division of labor in biomedical research using partial alphabetical authorship
2017
Contemporary biomedical research is performed by increasingly large teams. Consequently, an increasingly large number of individuals are being listed as authors in the bylines, which complicates the proper attribution of credit and responsibility to individual authors. Typically, more importance is given to the first and last authors, while it is assumed that the others (the middle authors) have made smaller contributions. However, this may not properly reflect the actual division of labor because some authors other than the first and last may have made major contributions. In practice, research teams may differentiate the main contributors from the rest by using partial alphabetical author…
Analysis of Production, Impact, and Scientific Collaboration on Difficult Airway Through the Web of Science and Scopus (1981-2013).
2017
Bibliometrics, the statistical analysis of written publications, is an increasingly popular approach to the assessment of scientific activity. Bibliometrics allows researchers to assess the impact of a field, or research area, and has been used to make decisions regarding research funding. Through bibliometric analysis, we hypothesized that a bibliometric analysis of difficult airway research would demonstrate a growth in authors and articles over time.Using the Web of Science (WoS) and Scopus databases, we conducted a search of published manuscripts on the difficult airway from January 1981 to December 2013. After removal of duplicates, we identified 2412 articles. We then analyzed the art…
Six Sigma in small- and medium-sized enterprises: a Black Belt project in the Swedish steel industry
2014
Many big companies around the world have solid Six Sigma infrastructures and it is easy to find in literature successful case studies. Conversely, small and medium-sized enterprises (SMEs) generally suffer lower attention in the literature. This happens because SMEs have only recently approached the methodology; they have weaker connection with the academia; or they do not rigorously pursue the frameworks. This paper is based on a Six Sigma project in a Swedish medium-sized company that produces steel tubes mainly for hydraulic applications. The project focused on the improvement of warehouse activities related to cutting processes. This Black Belt project was part of a Six Sigma education …
Exacus: Efficient and Exact Algorithms for Curves and Surfaces
2005
We present the first release of the Exacus C++ libraries. We aim for systematic support of non-linear geometry in software libraries. Our goals are efficiency, correctness, completeness, clarity of the design, modularity, flexibility, and ease of use. We present the generic design and structure of the libraries, which currently compute arrangements of curves and curve segments of low algebraic degree, and boolean operations on polygons bounded by such segments.
Matrix isolation studies and DFT calculations on molecular alkali metal bromates
2009
DFT and MP2 calculations have been carried out on a series of molecular alkali metal bromates MBrO3 (M = Na, K, Rb, Cs), and the results compared with matrix isolation IR studies on the vaporisation of the solid salts. For M = Na, K or Rb, no ternary molecular species were detected in the low temperature matrix, but vaporisation of solid caesium bromate at 730 K resulted in the formation of molecular CsBrO3, which was identified as having a C3v structure involving tridentate coordination. Additionally, the DFT and MP2 calculations provide estimates of the molecular parameters for all four MBrO3 species, and for the related MXO3 species CsClO3 and CsIO3. The proven stability of MBrO3 molecul…
ANALYSIS OF IMPACTS ON ELECTRIC POWER SYSTEM OPERATION OF LOAD MANAGEMENT IN RESIDENTIAL AND TERTIARY BUILDINGS
2012
Load management includes all the techniques, logics, actions and programs through which the electric utilities and the customers are able to manage loads absorption in a more prudent and efficient way; it determines economic benefits for the users, but also allows a network management and operation simpler and cheaper, determining technical and economic benefits. The present paper constitutes a detailed study of interventions and techniques to control demand in the residential and tertiary sectors and the effects that these actions have on the entire electrical system and its management. It discusses the implications of such control actions in terms of reduction of network losses and relate…
Offshore Assets in the Transition from ‘Traditional Business Practice’ to ‘Connected Business Eco-systems’
2020
In many industrial sectors we have already begun to see how new business ecosystems gradually emerge turning the traditional business practices upside down. Particularly within relatively conventional sectors, such as upstream oil and gas (O&G) and land-based process industry, we expect to see substantial changes in the years to come. In this paper, we elaborate on principal challenges related to major structural changes and core technology platforms for the oil industry identifying critical features and elaborating on emerging operational principles. This is based on a critical review of latest industry conditions and practices that are targeted towards the creation of new business models …