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Full-Text Articles in Science and Technology Studies

Flow Of Molten Slag Through Coke Channels, Hazem Labib George, Brian Joseph Monaghan, Raymond James Longbottom, Sheng Jason Chew, Peter Richard Austin Sep 2014

Flow Of Molten Slag Through Coke Channels, Hazem Labib George, Brian Joseph Monaghan, Raymond James Longbottom, Sheng Jason Chew, Peter Richard Austin

Brian Monaghan

In the lower zone of the iron making blast furnace, liquid iron and slag descend counter-current to reducing gases through a packed bed of coke. The characteristics of the flow of these liquids and their holdup influence product quality and furnace operation. The present study aimed to establish the criteria for the passage of slag through the narrow pore necks that form between coke particles. The flow of slag through coke pore necks has been simulated using an experimental technique that assesses slag flow from a funnel entering a narrow channel of known diameter. Synthetic coke was mainly used to …


Radial Consolidation Model Incorporating The Effects Of Vacuum Preloading And Non-Darcian Flow, Kourosh Kianfar, Buddhima Indraratna, Cholachat Rujikiatkamjorn Mar 2014

Radial Consolidation Model Incorporating The Effects Of Vacuum Preloading And Non-Darcian Flow, Kourosh Kianfar, Buddhima Indraratna, Cholachat Rujikiatkamjorn

Buddhima Indraratna

A modified 150 mm Rowe cell equipped with pore water pressure measurement was used to capture the flow relationship during vacuum-assisted radial consolidation. Based on the measured data, a radial consolidation model incorporating the effects of vacuum preloading is proposed, based on a non-linear relationship between the flow velocity and hydraulic gradient. The predictions of the proposed consolidation model are then compared with the predictions based on Hansbo’s Darcian and non- Darcian models. The agreement between the proposed model and the measured data is shown, and the advantages of the proposed model compared with the existing models are discussed. An …


Adaptive Stochastic Energy Flow Balancing In Smart Grid, Hassan Shirzeh, Fazel Naghdy, Philip Ciufo, Montserrat Ros Jan 2014

Adaptive Stochastic Energy Flow Balancing In Smart Grid, Hassan Shirzeh, Fazel Naghdy, Philip Ciufo, Montserrat Ros

Dr Philip Ciufo

A smart grid can be considered as an unstructured network of distributed interacting nodes represented by renewable energy sources, storage and loads. The nodes emerge or disappear in a stochastic manner due to the intermittent nature of natural sources such as wind speed and solar irradiation. Prediction and stochastic modelling of electrical energy flow is a critical characteristic in such a network to achieve load balancing and/or peak shaving in order to minimise the fluctuation between off peak and peak demand by power consumers. Before contributing energy to the network, a node acquires information about other nodes in the grid …


Optimal Power Flow With Variable Wind Conditions, S Durairaj, L Meegahapola, D Flynn, B Fox Dec 2013

Optimal Power Flow With Variable Wind Conditions, S Durairaj, L Meegahapola, D Flynn, B Fox

Dr Lasantha G Meegahapola

This paper presents simulation studies of an electric arc furnace (EAF) model in the MATLAB/SIMULINK environment. EAF was modeled as a current source controlled by a non-linear resistance. Voltage flicker, a phenomenon of annoying light intensity fluctuation, caused by EAF, has been a major power quality concern for both power companies and customers. A model was developed for the electric arc furnace and it was applied in the simulation studies of distribution static synchronous compensator (DSTATCOM) for voltage flicker mitigation. The controller for DSTATCOM was designed based on DQ-model for the reactive power management which helps in the mitigation of …


Kk-Theory And Spectral Flow In Von Neumann Algebras, J Kaad, R Nest, Adam C. Rennie Oct 2013

Kk-Theory And Spectral Flow In Von Neumann Algebras, J Kaad, R Nest, Adam C. Rennie

Associate Professor Adam Rennie

We present a definition of spectral flow for any norm closed ideal J in any von Neumann algebra N. Given a path of selfadjoint operators in N which are invertible in N/J, the spectral flow produces a class in Ko(J).Given a semifinite spectral triple (A, H, D) relative to (N, t) with A separable, we construct a class [D] ? KK1(A, K(N)). For a unitary u ? A, the von Neumann spectral flow between D and u*Du is equal to the Kasparov product [u]A[D], and is simply related to the numerical spectral flow, and a refined C*-spectral flow.


The Local Index Formula In Semifinite Von Neumann Algebras I: Spectral Flow, Alan Carey, John Phillips, Adam Rennie, Fyodor Sukochev Oct 2013

The Local Index Formula In Semifinite Von Neumann Algebras I: Spectral Flow, Alan Carey, John Phillips, Adam Rennie, Fyodor Sukochev

Associate Professor Adam Rennie

We generalise the local index formula of Connes and Moscovici to the case of spectral triples for a ∗-subalgebra A of a general semifinite von Neumann algebra. In this setting it gives a formula for spectral flow along a path joining an unbounded self-adjoint Breuer-Fredholm operator, affiliated to the von Neumann algebra, to a unitarily equivalent operator. Our proof is novel even in the setting of the original theorem and relies on the introduction of a function valued cocycle which is 'almost' a (b,B)-cocycle in the cyclic cohomology of A.


An Analytic Approach To Spectral Flow In Von Neumann Algebras, M-T Benameur, Alan Carey, John Phillips, Adam Rennie, Fyodor Sukochev, K Wojciechowski Oct 2013

An Analytic Approach To Spectral Flow In Von Neumann Algebras, M-T Benameur, Alan Carey, John Phillips, Adam Rennie, Fyodor Sukochev, K Wojciechowski

Associate Professor Adam Rennie

The analytic approach to spectral flow is about ten years old. In that time it has evolved to cover an ever wider range of examples. The most critical extension was to replace Fredholm operators in the classical sense by Breuer-Fredholm operators in a semifinite von Neumann algebra. The latter have continuous spectrum so that the notion of spectral flow turns out to be rather more difficult to deal with. However quite remarkably there is a uniform approach in which the proofs do not depend on discreteness of the spectrum of the operators in question. The first part of this paper …


Spectral Flow Invariants And Twisted Cyclic Theory For The Haar State On Suq(2), A L. Carey, A Rennie, K Tong Oct 2013

Spectral Flow Invariants And Twisted Cyclic Theory For The Haar State On Suq(2), A L. Carey, A Rennie, K Tong

Associate Professor Adam Rennie

In [A.L. Carey, J. Phillips, A. Rennie, Twisted cyclic theory and an index theory for the gauge invariant KMS state on Cuntz algebras. arXiv:0801.4605], we presented a K-theoretic approach to finding invariants of algebras with no non-trivial traces. This paper presents a new example that is more typical of the generic situation. This is the case of an algebra that admits only non-faithful traces, namely SUq.2/ and also KMS states. Our main results are index theorems (which calculate spectral flow), one using ordinary cyclic cohomology and the other using twisted cyclic cohomology, where the twisting comes from the generator of …