The cluster scanning system

Users with severe physical impairment often use computers with one or two switches using a scanning system. Scanning is a technique of successively highlighting portions of screen. This paper presents a new scanning system that works through clustering screen objects. The system is initially calibrated through simulation and later validated through a user trial. Results show that it outperforms existing block scanning systems.     

Reactive extrusion of zein with glyoxal

Cross‐linked zein has been produced using glyoxal (GLY) as the cross‐linking reagent via reactive extrusion for the first time in a twin screw extruder using dilute sodium hydroxide as catalyst. Tri(ethylene glycol) was used as a plasticizer for various items. The extrudate was then ground and processed using either compression or injection molding. At the highest level of GLY (6%), tri(ethylene glycol) was used at 10% as a plasticizer to allow further processing to take place. With this formulation, samples could be obtained from the injection mold, however, the samples did not hold their molded shape due to the elasticity of the sample at the mold temperature. When lower levels of GLY were used, injection molded sample bars of similar quality to control were obtained. The physical properties of these samples were similar to control. At GLY levels of 1.75% and higher, the samples were resistant to dissolution by acetic acid. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Chemical modification of metallocene‐based polyethylene–octene elastomer through solution grafting of acrylic acid and its effect on the physico‐mechanical properties

In the present work, the metallocene‐based polyethylene–octene elastomer (POE) was chemically modified by solution grafting of acrylic acid in presence of benzoyl peroxide. The relative proportions of graft and gel formation were optimized through %weight gain, Fourier Transform infrared spectroscopy, elemental analysis and proton nuclear magnetic resonance spectroscopy. The gel formation in the POE matrix was found to be the prime competitor. The effect of grafting at its maximum level on various physicomechanical properties was thoroughly investigated, using X‐ray diffraction analysis, differential scanning calorimetry, mechanical, dynamic mechanical, and thermogravimetric analysis. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Linear Combination of Atomic Orbitals Approximation in Nanocrystalline Yittria-Stabilized Zirconia Synthesized by Citrate–Nitrate Gel Combustion Process

Nanocrystalline yittria-stabilized zirconia (YSZ) compounds with yittria concentration varying between 8 and 12 mol% have been synthesized by gel combustion method followed by heat treatment at 550°C. The YSZs are found to posses stable face centered cubic structure at room temperature by X-ray diffractometry. The lattice parameter ' a ' showed an increasing trend with increasing concentration of yittria. The crystallite size estimated by Scherrer method was in the range of 7–10 nm. Band gap studies showed an increasing trend with increasing yittria concentration and are found to be consistent with respective lattice parameters following the tight binding approximation or linear combination of atomic orbitals approximation.     

Effect of amount, size, and spatial distribution of intermetallics on incipient localization during plastic deformation

Virtual microstructures having a systematic variation of amount, mean size, standard deviation of size, and spatial arrangement of intermetallics have been synthesized, and their deformation behavior in uniaxial tension has been evaluated using finite element analysis. Four spatial arrangements of intermetallics have been considered in this work, namely: random, clustered, and two-ordered structures. Various mathematical quantities have been developed to quantify the severity of deformation including plastic work density distribution (PWDD), percentile work-density volume criterion (PWC), and percentile stress volume criterion (PSC). This approach eliminates the need for an external trigger in FEA to achieve localization. The method developed has led to a better understanding of the effect of different microstructural attributes on the process of deformation. This has resulted in guidelines for optimizing the microstructure to minimize material damage and thereby maximize ductility.     

Robust control of HIV infection by antiretroviral therapy: a super‐twisting sliding mode control approach

Acquired immune deficiency syndrome is an epidemic infectious disease which is caused by the human immunodeficiency virus (HIV) and that has proliferated across worldwide. It has been a matter of concern for the scientific community to develop an antiretroviral therapy, which will prompt a rapid decline in viral abundance. With this motivation, this study proposes the design of a robust super twisting sliding mode controller based on output information for an uncertain HIV infection model. The control objective is to decrease the concentration of infected CD4+ T cells to a specified level by drug administration using only the output information of the uncertain HIV infection model which is total CD4+ T cell concentration. The robust output‐feedback controller has been developed in combination with a robust exact differentiator, functioning as an observer. The reported analysis demonstrates that the approach proposed here is capable of ensuring robust performance under several operating conditions, measurement and modelling error, parametric uncertainties and external disturbances and the simulation results prove the proficiency of the controller proposed.Inspec keywords: control system synthesis, observers, robust control, drugs, medical control systems, diseases, uncertain systems, variable structure systems, patient treatment, feedback, cellular biophysics, microorganismsOther keywords: robust control, antiretroviral therapy, sliding mode control approach, acquired immune deficiency syndrome, epidemic infectious disease, human immunodeficiency virus, scientific community, robust super, mode controller, output information, uncertain HIV infection model, control objective, infected CD4, total CD4, T cell concentration, robust output‐feedback controller, robust exact differentiator, robust performance     

Characteristics impedance spectroscopy: Tool to characterize ion-blocking phenomena

Scandia (Sc₂O₃) doped nano-crystalline zirconia powder was prepared by dissolution and co-precipitation method. Bulk specimens were prepared by sintering nano-powders at various temperatures. The characteristics admittance diagrams obtained from impedance spectroscopic measurement revealed the grain interior, defect (blocker) and grain boundary conductance. The ion-blocking model stressed the role played by the distribution of the current lines around the blockers and by the dielectric properties of these blockers. With temperature, no variation of the blocking factor was observed. This model is consistent as per similarity between the bulk and blocked conductance activation energies are concerned. The admittance diagram parameters were correlated to the geometrical parameters of the blockers.     

Dielectric waveguides in two-dimensional photonic bandgap materials

We investigate the performance and guiding properties of waveguides fabricated in a finite two-dimensional (2-D) photonic bandgap (PBG) structure. Confinement in the direction perpendicular to the plane of periodicity is achieved by fabricating the 2-D PBG structure in a high dielectric layer enclosed by two lower dielectric layers. Simulations using the finite-difference time-domain (FDTD) method are performed to investigate the energy transport in such waveguides. Good qualitative agreement is found with the experimental observations     

Health and wellness monitoring through wearable and ambient sensors: exemplars from home-based care of elderly with mild dementia

Monitoring and timely intervention are extremely important in the continuous management of health and wellness among all segments of the population, but particularly among those with mild dementia. In relation to this, we prescribe three design principles for the construction of services and applications. These are ambient intelligence, service continuity, and micro-context. In this paper, we provide three exemplars from our research and development activities that illustrate the use of these design principles in the construction of services and applications. All the applications are drawn from the field of care for mild dementia patients in their living quarters.