This paper aims to numerically study the compositional flow of two- and three-phase fluids in one-dimensional porous media and to make a comparison between several upwind…
This paper aims to numerically study the compositional flow of two- and three-phase fluids in one-dimensional porous media and to make a comparison between several upwind and central numerical schemes.
Implicit pressure explicit composition (IMPEC) procedure is used for discretization of governing equations. The pressure equation is solved implicitly, whereas the mass conservation equations are solved explicitly using different upwind (UPW) and central (CEN) numerical schemes. These include classical upwind (UPW-CLS), flux-based decomposition upwind (UPW-FLX), variable-based decomposition upwind (UPW-VAR), Roe’s upwind (UPW-ROE), local Lax–Friedrichs (CEN-LLF), dominant wave (CEN-DW), Harten–Lax–van Leer (HLL) and newly proposed modified dominant wave (CEN-MDW) schemes. To achieve higher resolution, high-order data generated by either monotone upstream-centered schemes for conservation laws (MUSCL) or weighted essentially non-oscillatory (WENO) reconstructions are used.
It was found that the new CEN-MDW scheme can accurately solve multiphase compositional flow equations. This scheme uses most of the information in flux function while it has a moderate computational cost as a consequence of using simple algebraic formula for the wave speed approximation. Moreover, numerically calculated wave structure is shown to be used as a tool for a priori estimation of problematic regions, i.e. degenerate, umbilic and elliptic points, which require applying correction procedures to produce physically acceptable (entropy) solutions.
This paper is concerned with one-dimensional study of compositional two- and three-phase flows in porous media. Temperature is assumed constant and the physical model accounts for miscibility and compressibility of fluids, whereas gravity and capillary effects are neglected.
The proposed numerical scheme can be efficiently used for solving two- and three-phase compositional flows in porous media with a low computational cost which is especially useful when the number of chemical species increases.
A new central scheme is proposed that leads to improved accuracy and computational efficiency. Moreover, to the best of authors knowledge, this is the first time that the wave structure of compositional model is investigated numerically to determine the problematic situations during numerical solution and adopt appropriate correction techniques.
The clustering of objects in a layered object storage system is by common consent an exceedingly difficult problem. Studies the performance of three heuristic placement…
The clustering of objects in a layered object storage system is by common consent an exceedingly difficult problem. Studies the performance of three heuristic placement algorithms. A series of eight reasonably realistic case studies were used as a benchmark battery, and several hundred experiments were carried out to evaluate results of using the algorithms. Presents the results and the insights gained from the study.
The following bibliography focuses mainly on programs which can run on IBM microcomputers and compatibles under the operating system PC DOS/MS DOS, and which can be used…
The following bibliography focuses mainly on programs which can run on IBM microcomputers and compatibles under the operating system PC DOS/MS DOS, and which can be used in online information and documentation work. They fall into the following categories:
Incivility is widespread in the workplace and has been shown to have significant affective and behavioral consequences. However, the authors still have a limited…
Incivility is widespread in the workplace and has been shown to have significant affective and behavioral consequences. However, the authors still have a limited understanding as to whether, how and when discrete incivility events impact team performance. Adopting a resource depletion perspective and focusing on the cognitive implications of such events, the authors introduce a multi-level model linking the adverse effects of such events on team members’ working memory – the “workbench” of the cognitive system where most planning, analyses, and management of goals occur – to team effectiveness. The model which the authors develop proposes that that uncivil interpersonal behavior in general, and rudeness – a central manifestation of incivility – in particular, may place a significant drain on individuals’ working memory capacity, affecting team effectiveness via its effects on individual performance and coordination-related team emergent states and action-phase processes. In the context of this model, the authors offer an overarching framework for making sense of disparate findings regarding how, why and when incivility affects performance outcomes at multiple levels. More specifically, the authors use this framework to: (a) suggest how individual-level cognitive impairment and weakened coordinative team processes may mediate these incivility-based effects, and (b) explain how event, context, and individual difference factors moderators may attenuate or exacerbate these cognition-mediated effects.
This paper aims to perform a comparative study between capabilities of two numerical schemes from two main branches of numerical methods for solving hyperbolic…
This paper aims to perform a comparative study between capabilities of two numerical schemes from two main branches of numerical methods for solving hyperbolic conservation equations.
The accuracy and performance of a newly developed high‐resolution central scheme vs a higher‐order Godunov‐based method are evaluated in the context of black‐oil reservoir simulations. Both methods are modified enabling study of applications that are not strictly hyperbolic and exhibit local linear degeneracies in their wave structure.
The numerical computations show that while both schemes produce results with virtually the same accuracy, the Godunov method reproduces slightly more accurate results at the expense of calculation of eigen‐structures.
The paper investigates only one dimensional problems, but the idea can be easily extended to multi‐dimensional problems.
The paper shows the strengths and weaknesses of two practical numerical methods.
Such comparative study has not been published elsewhere and in particular, the performance of numerical methods on simulating hysteresis effect in hydrocarbon reservoirs has not been investigated in detail before.
In this chapter, we explore the effect of export exit on subsequent firm performance in a sample of 13,629 Belgian small and medium-sized enterprises (SMEs). We find that…
In this chapter, we explore the effect of export exit on subsequent firm performance in a sample of 13,629 Belgian small and medium-sized enterprises (SMEs). We find that firms that stop exporting have lower profitability and profitability declines even further after they exit foreign markets. Firms that were highly dependent on revenues from exports and firms exiting multiple markets are more negatively affected, as reflected in lower post-exit survival rates and profitability. However, export duration or exiting institutionally distant markets does not have a significant impact on subsequent firm performance. Finally, although firm performance is negatively affected by exit, failed internationalization does not always lead to firm failure. Theoretical and practitioner implications are discussed.
In 1967 Aslib Research and Development Department published a note describing experimental work on computer‐aided typesetting, and announcing that further research was planned. The proposed programme of work was carried out by the authors of the present paper, during their sojourns as members of the Department. The results are here reported.
Nobody concerned with political economy can neglect the history of economic doctrines. Structural changes in the economy and society influence economic thinking and…
Nobody concerned with political economy can neglect the history of economic doctrines. Structural changes in the economy and society influence economic thinking and, conversely, innovative thought structures and attitudes have almost always forced economic institutions and modes of behaviour to adjust. We learn from the history of economic doctrines how a particular theory emerged and whether, and in which environment, it could take root. We can see how a school evolves out of a common methodological perception and similar techniques of analysis, and how it has to establish itself. The interaction between unresolved problems on the one hand, and the search for better solutions or explanations on the other, leads to a change in paradigma and to the formation of new lines of reasoning. As long as the real world is subject to progress and change scientific search for explanation must out of necessity continue.
In this chapter, the authors discuss the process of embedding experiential learning in a required ethics and diversity course (ED200). The course is a model of humanistic…
In this chapter, the authors discuss the process of embedding experiential learning in a required ethics and diversity course (ED200). The course is a model of humanistic education in which students develop disciplinary-based methodological expertise while also drawing on cross-disciplinary, inclusive, problem-solving skills. The authors suggest that in a course that challenges students to think about their lives in community, engagement with that community plays a critical role in humanizing the learning experience. This pedagogical emphasis on experiential learning, instantiated as community engagement, unites the foci of ethics and diversity through students’ practical application of and reflection on their experiences to enhance ethical and cultural self-awareness. In the process, it also fosters a desire for participatory and justice-oriented citizenship (Westheimer & Kahne, 2004). In what follows, the authors provide a history of the development of ED200. The authors then justify the inclusion of experiential learning in the course from theoretical and practical perspectives: Why is it valuable to include experiential learning in this course and how does it advance the goal of developing critically engaged citizens through improving ethical reasoning skills and actionable understanding of diversity? Last, the authors detail positive impacts and implementation challenges and indicate next steps for continued development.
The need to assess the perceptions of tomorrow's managers remains critical to forecasting social changes in the management environment. This study examines the views of…
The need to assess the perceptions of tomorrow's managers remains critical to forecasting social changes in the management environment. This study examines the views of upper division business students at three diverse American institutions. Findings suggest that: (1) women and men both advocate more participation in decision making, (2) women and men both recognize the seriousness of sexual harassment in the workplace, (3) minority students demonstrate the greatest interest in entrepreneurial careers, and (4) support for drug testing is relatively strong except for suspicions about those doing the testing.