Simplified mechanistic model for the separation of dispersed oil-water horizontal pipe flows

A mechanistic model that predicts the separation of oil-water dispersed horizontal pipe flows was investigated. Different droplet diameter averages were implemented in the model and the accuracy of the resulting predictions was assessed by comparing each case against experimental data. The experimental data used was obtained in a pilot scale two-phase flow facility using tap water and oil (828 kg m-3, 5.5 mPa s) as test fluids. The results show that the separation length is highly sensitive to the drop diameter, but further investigation is required to determine which drop diameter average produces more accurate predictions of the flow profile

Using discrete Darboux polynomials to detect and determine preserved measures and integrals of rational maps

In this Letter we propose a systematic approach for detecting and calculating preserved measures and integrals of a rational map. The approach is based on the use of cofactors and Discrete Darboux Polynomials and relies on the use of symbolic algebra tools. Given sufficient computing power, all rational preserved integrals can be found. We show, in two examples, how to use this method to detect and determine preserved measures and integrals of the considered rational maps.Comment: 8 pages, 1 Figur

Attitudes towards Cypriot Greek and Standard Modern Greek in London’s Greek Cypriot community

Aim To investigate whether the positive attitudes towards Standard Modern Greek and the mixture of positive and negative attitudes towards Cypriot Greek that have been documented in Cyprus are also present in London's Greek Cypriot community. Approach Unlike previous quantitative works, the study reported in this article was qualitative and aimed at capturing the ways in which attitudes and attitude-driven practices are experienced by members of London's diasporic community. Data and Analysis Data were collected by means of semi-structured, sociolinguistic interviews with 28 members of the community. All participants were second-generation heritage speakers, successive bilinguals in Cypriot Greek and English, and successive bidialectal speakers in Cypriot Greek and Standard Modern Greek. The data were analysed qualitatively (thematic analysis). Findings – Positive perceptions of Standard Modern Greek and mixed perceptions, both positive and negative, of Cypriot Greek are found in the context of London. – As in Cyprus, Standard Modern Greek is perceived as a prestigious, proper and 'correct' variety of Greek. Cypriot Greek, in contrast, is described as a villagey, heavy and even broken variety. – Greek complementary schools play a key role in engendering these attitudes. – Unlike in Cyprus, in the London community, the use of Cypriot Greek is also discouraged in informal settings such as the home. Originality Papapavlou & Pavlou contended that "there are no signs of negative attitudes towards Cypriot Greek [in London]" (2001, p. 104). This research shows this claim to be false. Significance/Implications Negative attitudes towards Cypriot Greek lead to a community-wide preference for the use of Standard Modern Greek in communication with other members of the Greek Cypriot community, which poses a great threat to the intergenerational transmission and maintenance of Cypriot Greek as a heritage language in London

Data-flow vs control-flow for extreme level computing

NoThis paper challenges the current thinking for building High Performance Computing (HPC) Systems, which is currently based on the sequential computing also known as the von Neumann model, by proposing the use of Novel systems based on the Dynamic Data-Flow model of computation. The switch to Multi-core chips has brought the Parallel Processing into the mainstream. The computing industry and research community were forced to do this switch because they hit the Power and Memory walls. Will the same happen with HPC? The United States through its DARPA agency commissioned a study in 2007 to determine what kind of technologies will be needed to build an Exaflop computer. The head of the study was very pessimistic about the possibility of having an Exaflop computer in the foreseeable future. We believe that many of the findings that caused the pessimistic outlook were due to the limitations of the sequential model. A paradigm shift might be needed in order to achieve the affordable Exascale class Supercomputers

Programming Abstractions and Toolchain for Dataflow Multithreading Architectures

The need to exploit multi-core systems for parallel processing has revived the concept of dataflow. In particular, the Dataflow Multithreading architectures have proven to be good candidates for these systems. In this work we propose an abstraction layer that enables compiling and running a program written for an abstract Dataflow Multithreading architecture on different implementations. More specifically, we present a set of compiler directives that provide the programmer with the means to express most types of dependencies between code segments. In addition, we present the corresponding toolchain that transforms this code into a form that can be compiled for different implementations of the model. As a case study for this work, we present the usage of the toolchain for the TFlux and DTA architectures