Solubility of Mn stabilized cubic zirconia nanostructures

Mn-stabilized cubic zirconia nanostructures (Zr_1?xMn_xO₂, x = 0.10, x = 0.15 and x = 0.20) have been prepared using chemical precipitation method for different doping concentrations. The prepared powders have been characterized by X-ray diffractometer for structural analysis, vibrating sample magnetometer for analyzing magnetic properties, scanning electron microcopy–elemental compositional analysis using X-ray for morphological and elemental compositional analysis. Room temperature ferromagnetism has been found at around x = 0.15. For high doping effect of Mn impurity at host lattice, secondary phase has been detected at around x = 0.20 when exceeding the solubility limit of cubic zirconia. Due to ferromagnetic behavior, Mn doped ZrO₂ nanostructures can be considered as good candidates for spintronics applications within their solubility limit.     

Prediction of the tensile capacity of cold formed angles experiencing shear lag

The present study deals with the shear lag phenomenon in cold formed angles under tension, which are connected on one leg. A new expression for shear lag factor which represents the net section reduction coefficient has been suggested in the present paper. The proposed expression based on the regression analysis of 108 experimental results reported in the literature is validated by experiments involving net section failure in angles under tension. Totally 18 experiments were carried out on single angles fastened with bolts to the gusset plates under tension loaded upto net section rupture mode of failure. The experimental test parameters considered are number of bolts, pitch and shear lag distances and ratio of connected leg length to unconnected leg length. The tensile capacities are evaluated by various specifications such as AS/NZS:4600:2005, NAS:2001, AISC:2005, BS:5950-Part5:1998, IS:800-2007 and the proposed equation. A comparative study of tensile capacities predicted based on various codes and the experiment results is presented in this paper. For the tested range of specimens, both NAS:2001 and AISC:2005 standards over-predicted the capacities for all the specimens. The IS:800-2007 and AS/NZS 4600:2005 predictions are good for the specimens with three bolted connections and unconservative in the case of specimen with two bolts. Both BS:5950-Part-5:1998 and the proposed equation for IS:801 predict good estimate of the tensile capacity of cold formed angle members. The proposed equation for cold formed steel tension members, which is in the same format of IS:800 (2007) (Indian code for Hot rolled steel design), has been demonstrated to be good.     

Modularization of a Large-Scale Business Application: A Case Study

Large software systems, developed over several years, are the backbone of industries such as banking, retail, transportation, and telecommunications. With multiple bug fixes and feature enhancements, these systems gradually deviate from the intended architecture and deteriorate into unmanageable monoliths. This article presents a case study of a banking application besot with such problems and the modularization approach that the company adopted as a solution. It also highlights benefits unearthed as a result of this reengineering exercise.     

Integration of Ceramics Research with the Development of a Microsystem

Rapid implementation of new materials into engineering systems may require a paradigm shift in our approach to materials research. One option is to obtain fundamental material properties from experimental systems that can also serve as devices. This concept is applied to the measurement of Young's modulus of a novel ceramic, a polymer-derived silicon carbonitride (SiCN), directly from the performance of a microelectromechanical system (MEMS) device. The device is an electrostatic actuator. The flexure resistance of the arms of the actuator is measured and analyzed for the elastic modulus of SiCN. The comparison between theory and experiment yields a value for Young's modulus in the range 130–155 GPa.     

Polyaniline Salts and Complexes as Catalyst in Bisindole Synthesis

Polyaniline salts are prepared by doping of polyaniline base with different Bronsted acids (H₂SO₄, HNO₃ and H₃PO₄), organic acid — p-toluene sulfonic acid (PTSA) and Iodine (I₂). Polyaniline complexes are also prepared using Lewis acids (BF₃, AlCl₃ and SnCl₂). Polyaniline salts and polyaniline complexes are characterized by physical, electrical and spectral methods. Polyaniline salts and polyaniline complexes are used as catalyst for the first time in bisindole synthesis. Bisindole (3,3′-bis(indolyl)phenylmethane) is obtained in excellent yields with simple and more environmental benign procedure. The use of polyaniline catalysts are feasible because of their easy preparation, easy handling, stability, easy recovery, reusability, good activity and eco-friendly.     

An algorithm for detecting roads and obstacles in radar images

This paper describes an algorithm for detecting roads and obstacles in radar data taken from a millimeter-wave imaging platform mounted on a stationary automobile. Such an algorithm is useful in a system that provides all-weather driving assistance. Road boundaries are detected first. The prior shape of the road boundaries is modeled as a deformable template that describes the road edges in terms of its curvature, orientation, and offset. This template is matched to the underlying gradient field of the radar data using a new criterion. The Metropolis algorithm is used to deform the template so that it “best” matches the underlying gradient field. Obstacles are detected next. The radar returns from image pixels that are identified as being part of the road are processed again, and their power levels are compared to a threshold. Pixels belonging to the road that return a significant (greater than a fixed threshold) amount of incident radar power are identified as potential obstacles. The performance of the algorithm on a large all-weather data set is documented. The road edges and obstacles detected are consistently close to ground truth over the entire data set. A new method for computing the gradient field of radar data is also reported, along with an exposition of the millimeter-wave radar imaging process from a signal-processing perspective     

Combined influence of throughflow and Soret effect on the onset of Marangoni convection

The onset of Marangoni convection with throughflow and the Soret effect in a top-free and bottom-rigid horizontal fluid layer is studied using the normal mode method for different types of thermal and solutal boundary combinations. The bottom surface is either conducting or insulating to temperature and solute concentration perturbations. The resulting eigenvalue problem is solved exactly by assuming that stationary convection is exhibited at the neutral state. It is found that the destabilizing behavior of a small amount of throughflow described by Nield (J Fluid Mech 185:353–360, 1987) becomes more significant in the presence of Soret effect for some boundary combinations. The results are consistent with the existing results in the literature.     

Influence of oxygen pressure on structural,optical and magnetic properties of pure ZnO films

In this paper, we study the influence of oxygen pressure on structural, optical and magnetic properties of pure ZnO films. The chemical compositions and thickness of the film were estimated by Rutherford backscattering spectrometry measurements. X-ray diffraction patterns show all the films are in single phase and preferred along (002) orientation. With an increase of oxygen pressure, grain growth and average root mean square roughness is found to be increased. It is found that the intensity of UV emission peak increases whereas visible emission peak decreases in intensity with an increase of oxygen pressure. From the magnetization measurements, it is observed that ZnO film grown without oxygen pressure shows an enhanced ferromagnetic behaviour than that of the films grown with oxygen pressure of 0.05 and 0.1 mbar.     

Synthesis and characterization of poly(N-vinylpyrrolidine)-silica hybrid shell coated cadmium selenide / cadmium sulphide and cadmium selenide / zinc sulfide nanoparticles

Poly(N-vinylpyrrolidine)-silica hybrid shell coated cadmium selenide / cadmium sulphide and cadmium selenide / zinc sulfide nanoparticles were synthesized by combining the organometallic and single “step” modified Stober method. The synthesized nanoparticles were characterized by atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, and a spectrofluorometer. Concluding, this report has provided important insights into the design of new water-soluble polymer silica hybrid shell coated quantum dots nanoparticles for biomedical, analytical and catalytic applications.