An under-met and over-met expectations model of employee reactions to merit raises.

The authors developed a model of how raise expectations influence the relationship between merit pay raises and employee reactions and tested it using a sample of hospital employees. Pay-for-performance (PFP) perceptions were consistently related to personal reactions (e.g., pay raise happiness, pay-level satisfaction, and turnover intentions). Merit pay raises were strongly related to reactions only among employees with high raise expectations and high PFP perceptions. The interactive effects of under-met/over-met expectations and PFP perceptions were mediated by the extent to which participants saw the raise as generous and they were happy with the raises they received. The authors discuss the implications of these findings for expectation-fulfillment theories, merit pay research, and the administration of incentives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

SubXPCA and a generalized feature partitioning approach to principal component analysis

In this paper we propose a general feature partitioning framework to PCA computation and raise issues of cross-sub-pattern correlation, feature ordering dependence, selection of sub-pattern size, overlap of sub-patterns and selection of principal components. These issues are critical to the design and performance of feature partitioning approaches to PCA computation. We show several open issues and present a novel algorithm, SubXPCA which proposes a solution to the cross-sub-pattern correlation issue in the feature partitioning framework. SubXPCA is shown to be a general technique since we derive PCA and SubPCA as special cases of SubXPCA. We show SubXPCA has theoretically better time complexity as compared to PCA. Comprehensive experimentation on UCI repository data and face data sets (ORL, CMU, Yale) confirms the superiority of SubXPCA with better classification accuracy. SubXPCA not only has better time performance but is also superior in its summarization of variance as compared to SubPCA. SubXPCA is shown to be robust in its performance with respect to feature ordering and overlapped sub-patterns.     

Effects of Material Composition and Microstructural Features on Dry Sliding Wear Behaviour of Fe–TiC Composite and a Cobalt-Based Stellite

This investigation deals with the influence of hardfacing En31 steel separately with Fe–TiC composite and commercial cobalt base (stellite 6) material on their sliding wear behaviour at 2.94 m/s speed and varying applied pressures. Wear response of the samples was substantiated through the scanning electron microscopic studies of the wear surfaces, subsurface regions and debris particles. The hardfaced samples revealed superior wear performance than that of the substrate. Further, the steel hardfaced with cobalt-based stellite offered higher wear resistance over the one overlayed with Fe–TiC composite. The applied pressure controlled the wear behaviour (rate) in a complex manner and its influence was dependent on material composition/microconstituents and test conditions. The friction coefficient got reduced with pressure except in the case of the Fe–TiC composite overlay beyond 2 MPa. The hardfaced samples were noted to be better suited for more severe conditions. Microcracking was quite frequently observed on wear surfaces of the hardfaced material especially under mild wear conditions. Sticking of fine debris particles on to the specimen surface was also observed.     

Pulsed laser deposited ZnO films and their humidity sensing behavior

The present paper describes an opto-electronic humidity sensor based on thin film of zinc oxide prepared by pulsed laser deposition method. Being optical in nature it gives electromagnetic disturbance-free monitoring. The sensing element is a right-angled isosceles prism with its base coated with ZnO thin film. Films have been characterized by XRD, SEM, and optical transmission. Film grown with substrate at room temperature is amorphous whereas that grown at elevated temperature is single crystalline with grain size 38.52 nm. Film deposited at room temperature is sensitive to humidity over a wide range i.e. 5–90RH% while that deposited at elevated temperature is found to be insensitive to humidity. The sensor shows better sensitivity for higher range of humidity. The response and recovery time of the sensor element have also been evaluated. This sensor configuration can be used for on-line applications and in-situ monitoring.     

Effect of elastomer characteristics on fiber optic force sensing performance in biomedical robotics applications

Miniaturized and “smart” sensors are required for research in biology, physiology, and biomechanics, and they have extremely important clinical applications for diagnostics and minimally invasive surgery. Fiber optic sensors have been proven to provide advantages compared to conventional sensors and high potential for biomechanical and biomedical applications. They are small, easy to operate, minimally invasive with low risk, more accurate, and inexpensive. This paper reports the design and modeling of a fiber optic force sensor that is capable of measuring compliance for a contact force of up to 1 N. The main objective of this study is to design and model a fiber optic sensor capable of measuring the total force applied on an object. A polydimethylsiloxane (PDMS) elastomer film with a thickness of 1.2 mm is placed between an optical fiber tip and an object, and it is used for measuring the force applied on a rigid element. The compliance of the fiber optic force sensor is measured by recording the response of PDMS elastomer films under different load conditions. We use finite element modeling results as a basis for comparing experimental data. The agreement between theoretical predictions and experimental data is reasonable and within an acceptable range.     

Bending membranes on demand: fluid phospholipid bilayers on topographically deformable substrates

We combine hierarchical surface wrinkling of elastomers with lipid membrane deposition techniques to dynamically template complex three-dimensional topographies onto supported lipid bilayers. The real-time introduction of corresponding nano- to micrometer scale curvatures triggers spatially periodic, elastic bending of the bilayer, accompanied by molecular-level reorganizations. This ability to dynamically impose curvatures on supported bilayers and the ensuing re-equilibration promises fundamental material and biophysical investigations of curvature-dependent, static heterogeneities and dynamic reorganizations pervasive in biological membranes.     

New Protocol for the Enumeration of Salmonella and Shigella from Wastewater

Development of stringent standards for the microbiological quality of the wastewater has necessitated a sensitive and efficient method for the enumeration of pathogens present in wastewaters. Standard methods are used all over the world for the identification of microbes by the public health engineers. However, this conventional method has serious problems, which are related to the long detection time required for turbid wastewaters and corresponding reduced isolation of the microbes. The Conventional method has been modified by omitting the concentration and blending steps, and named as the “Direct method.” The Direct method should be able to provide maximum possible recovery specifically for the turbid wastewaters. An existing sewage treatment plant was selected to carry out the study over a period of six months. Samples were collected from the various stages of treatment and analyzed for the isolation of Salmonella and Shigella using the Conventional method and the proposed direct method. The direct method required less time compared to the Conventional method. More importantly, the recovery of Salmonella and Shigella has improved by 105% and 276%, respectively, over the Conventional method. The consistent improvement in the recovery of the pathogens has been seen at various stages of the sewage treatment.     

Managing fuel variability in LPG-based PEM fuel cell systems – I: Thermodynamic simulations

Hydrocarbon-based polymer electrolyte membrane fuel cell systems are promising solutions for auxiliary power units and remote systems. The sequence of steam reforming, water–gas shift and preferential oxidation reactors is a common fuel processing methodology. The heat released by burning the hydrogen-depleted anode waste gas is utilized to drive the endothermic reforming reaction and to generate steam, while the other two sub-processes are exothermic. Balancing these heat fluxes, while maintaining the narrow temperature windows required for each of these reactions, is a key system control challenge. Strategies based on a priori knowledge of fuel composition result in instability, reduction in system efficiency or transgression of safe limits in critical parameters when fuel composition varies. To address this, we have developed and implemented a control strategy that uses more readily measurable quantities to perform control actions, and is independent of knowledge about exact fuel composition or flow rate. In this paper, we analyze the effectiveness of the new control strategy by quantifying its effects on liquefied petroleum gas based polymer electrolyte membrane fuel cell systems. Results indicate that even in extreme cases of fuel composition variation, this control strategy enables the determination of set points such that the system efficiency and other critical parameters are held in a narrow range around optimal values.