Performance analysis of a three-phase induction motor under mixed eccentricity condition

A substantial proportion of induction motor faults are eccentricity related. In practice, static and dynamic eccentricities happen to exist together. With this point in mind, an analytical approach to evaluate the performance of a three-phase induction motor under mixed eccentric conditions is presented in this paper. A clear and step-by-step theoretical analysis, explaining completely the presence of certain harmonics in the line-current spectrum in the presence of eccentricity, is discussed. More importantly, it is shown for the first time that a link exists between the low- and high-frequency elements of these harmonics. It is also shown that these high-frequency components are not very strong in all types of machine. These results will be useful in generating rules and laws to formulate online tools for machine condition monitoring. Finite-element results to substantiate the inductance values used in the simulation are also included. The analysis is validated by the line-current spectrum of the eccentric machine obtained through simulation using the modified winding-function approach (MWFA) and experimentation.     

The Rh-Ru (rhodium-ruthenium) system

Conclusions The Rh-Ru phase diagram evaluated from the available data is a simple peritectic type. No experimental observations of the liquidus are available. Both terminal solid solutions show considerable compositional ranges that are almost temperature independent.     

Micellization of Some Bile Salts in Binary Aqueous Solvent Mixtures

The micellization behavior of bile salts—sodium cholate and sodium deoxycholate was studied in aqueous methanol, ethanol and ethylene glycol mixtures (10–20 % v/v) over a temperature range (300–320 K) by surface tension and conductivity methods. Critical micelle concentration, extent of counter ion binding (α), interfacial property (A _min, ζ_max, π-CMC, $ \Updelta G_{\text{ad}}^{ \circ } $ ) and thermodynamic parameters ( $ \Updelta G_{\text{m}}^{ \circ } $ , $ \Updelta H_{\text{m}}^{ \circ } $ , $ \Updelta S_{\text{m}}^{ \circ } $ ) for the micellization process are reported and discussed.     

Analysis and optimization of nonequilibrium capillary electrophoresis of alpha-fetoprotein isoforms

The L3 isoform of alpha-fetoprotein (AFP) is a specific marker for hepatocellular carcinoma. The separation and quantitation of L3 isoform from the L1 isoform is facilitated by Lens culinaris agglutin (LCA) affinity of the L3 isoform. The affinity-based separation is characterized by nonequilibrium conditions since electrophoresis perturbs the species concentrations away from equilibrium. The design of such separations requires careful consideration of the interplay between the reaction, diffusion, and separation time scales. We performed experiments to investigate the effect of separation parameters such as LCA concentration and CE voltage on the L1-L3 separation dynamics. We also describe a comprehensive mathematical model to predict electropherograms for affinity-based separations. The model includes the effects of molecular diffusion, electromigration, nonequilibrium reaction, and detection process. Together, the results demonstrate a process by which to optimize the affinity-based separations of AFP isoforms. We also obtained the kinetic rate constants for LCA affinity (kon=1.6x10(3) mol(-1) s(-1) L, koff=1x10(-3) s(-1)) by comparing the model predictions with experimental data. This study provides insight into the physics of affinity-based separations and can be extended to describe and optimize other nonequilibrium CE systems.     

Design and analysis of optimal material distribution policies in flexible manufacturing systems using a single AGV

Modern automated manufacturing processes employ Automated Guided Vehicle (AGV) for material handling, which serve several machine centres (MC) in a factory. Waiting time for resources such as AGVs are the longest elements that make up the Manufacturing Lead Time (MLT). Hence, optimal scheduling of AGVs can significantly help to increase the efficiency of the manufacturing process by minimizing the idle time of MCs waiting for the raw materials. In this paper, we will analyse the requirements for an optimal schedule and then provide a mathematical framework for an efficient schedule of material delivery by an AGV. The optimal schedule depends on several factors, such as the processing speeds of MCs, the speed and the material carrying capacity of the AGV, and system dependent overheads (such as loading and unloading time, machine set-up time, distance travelled, etc). A mathematical model is developed and then a strategy for optimal material distribution of the available raw material to the MCs is derived. With this model, the optimal number of MCs to be utilized will also be determined. Finally, the material delivery schedule employing multiple journeys to the MCs by the AGV will be carried out. Through rigorous analysis and simulation experiments, we shall show that such a delivery strategy will optimize the overall performance.     

Building a successful relationship in business process outsourcing: an exploratory study

In the past decade, business process outsourcing (BPO) has emerged as an important economic and business issue. Successful offshoring and outsourcing of business processes to low-cost destinations has made BPO a strategic decision. Inconsistencies at the client and service provider levels globally are requiring clients to build competencies in outsourcing management. Clients are further pushing service providers to build capabilities such as business process management and information technology management competencies. A research survey is carried out with European clients to identify the critical competencies of the service provider and clients for building a successful relationship. The survey indicates that the clients’ focus is on BPO outcome delivery for building successful relationship and not so much on the service provider's competencies.     

Dynamic Load Balancing and Pricing in Grid Computing with Communication Delay

Due to the emergence of Grid computing over the Internet, there is presently a need for dynamic load balancing algorithms which take into account the characteristics of Grid computing environments. In this paper, we consider a Grid architecture where computers belong to dispersed administrative domains or groups which are connected with heterogeneous communication bandwidths. We address the problem of determining which group an arriving job should be allocated to and how its load can be distributed among computers in the group to optimize the performance. We propose algorithms which guarantee finding a load distribution over computers in a group that leads to the minimum response time or computational cost. We then study the effect of pricing on load distribution by considering a simple pricing function. We develop three fully distributed algorithms to decide which group the load should be allocated to, taking into account the communication cost among groups. These algorithms use different information exchange methods and a resource estimation technique to improve the accuracy of load balancing. We conducted extensive simulations to evaluate the performance of the proposed algorithms and strategies.