Correlations and fluctuations of a confined electron gas

The grand potential $\Omega$ and the response $R = - \partial \Omega /\partial x$ of a phase-coherent confined noninteracting electron gas depend sensitively on chemical potential $\mu$ or external parameter $x$. We compute their autocorrelation as a function of $\mu$, $x$ and temperature. The result is related to the short-time dynamics of the corresponding classical system, implying in general the absence of a universal regime. Chaotic, diffusive and integrable motions are investigated, and illustrated numerically. The autocorrelation of the persistent current of a disordered mesoscopic ring is also computed.Comment: 12 pages, 1 figure, to appear in Phys. Rev.

A Computer Oriented Algorithm to Determine the Raw-Mixture Composition for Sintering

Sintering is an agglomeration process of fine part-icles and widely used as a standard method for preparation of blast furnace-feed. In iron-ore sintering, iron ore fines viz. iron ore crushed to ---10 mm size, classifier fines, cyclone underflow, blue-dust etc. together with other iron-bearing waste materials viz. mill-scale, flue dust etc. are mixed with fluxing materials like limestone, dolomite etc. and sintered in a continuously operated sinter strand or a bench-scale sinter pot. The sintering of fine particles results from incipient fusion of materi-als due to heat liberated by combustion of coke-breeze incorporated in the raw mixture and also exothermic heat liberated through complex chemical reactions taking place during the process of sintering. Water added during mixing helps to maintain a proper permeability and return fines act as a supporting structure for the mixture

Structure of Complexes of 2-Phenylazopyridine with Perchlorate Halides of Ni(II) & with Ferrous Iodide

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Recursive bayesian approaches for auto calibration in drift aware wireless sensor networks

The purpose for wireless sensor networks is to deploy low cost sensors with sufficient computing and communication capabilities to support networked sensing applications. Even when the sensors are properly calibrated at the time of their deployment, they develop drift in their readings leading to biased sensor measurements. Noting that a physical phenomenon in a certain area follows some spatio-temporal correlation, we assume that the sensors readings in that area are correlated. We also assume that the instantiations of drifts are uncorrelated. Based on these assumptions, and inspired by the resemblance of registration problem in radar target tracking with the bias error problem in wireless sensor networks, we follow a Bayesian framework to solve the Drift/Bias problem in wireless sensor networks. We present two methods for solving the drift problem in a densely deployed sensor network, one for smooth drifts and the other for unsmooth drifts. We also show that both methods successfully detect and correct sensor errors and extend the effective life time of the sensor network

Estimation of aggregate reserve with point-of-load voltage control

Voltage dependent loads can collectively provide a certain amount of power reserve (by virtue of the ability to change their power consumption within the stipulated voltage tolerance) which could be exploited for grid frequency regulation through voltage control at the substation/feeder or at the point of load. The amount of such power reserve would vary with time of the day depending on the incidence of different types of voltage dependent loads and also the voltage profile across the feeders. It is important for the grid operators to know the aggregate power reserve from the voltage dependent loads during different times of the day in order to schedule other forms of reserves accordingly. This paper presents a methodology to estimate such power reserve from the measured power and voltage at the bulk supply points without knowing the actual distribution network topology and/or load profile of individual customers. The proposed method is applied to estimate the time variation of the aggregate reserve offered by the voltage dependent loads within the domestic sector in Great Britain (GB). Studies on a standard IEEE distribution network are presented to validate the estimated reserve margins under typical voltage profiles across the distribution feeders

Improving labour relations performance using a Simplified Drum Buffer Rope (S-DBR) technique

The purpose of this research is to describe an implementation of Simplified Drum Buffer Rope (S-DBR), a scheduling methodology under Theory of Constraints, in service operations of a US military base. In doing so, this research contributes in two ways. For practitioners, this research is the first to show how S-DBR methodology can be utilised to improve the performance of labour relations. For academicians, this research is one of only a few to address the how questions of S-DBR use in a service context

Lean Systems: Soft OR in practice

Lean implementation involves eliminating all forms of waste (for example, defects or overproduction) and consists of many improvement strategies or systems such as mistake proofing (Poka-Yoke) and Single Minute Exchange of Die (a.k.a. quick changeover). The purpose of this study is to discuss a successful lean or waste elimination initiative for a building products company. Specifically, this study describes how mistake proofing and quick changeover systems were implemented using soft OR practices or Soft Systems Methodology (SSM). Essentially, SSM consisted of four sequential stages, namely (1) problem identification, (2) basic approaches to improvement, (3) making plans for improvement, and (4) translating improvement plans into reality. The study contributes in two ways: for practicing managers, it shows that at the core of lean is soft OR practices, and for academicians, it provides directions for future research