Estimation of the surface velocity of debris flow with computer-based spatial filtering

A computer-based spatial-filtering velocimeter to measure the surface velocity of natural debris flow is described. This is a simple and interesting technique implemented with a spatial filter constructed as a software program that processes the video image of debris flow instead of a hardware implementation. The surface velocity of the debris flow at the Mt. Yakedake Volcano, Japan, was estimated by this computer-based spatial-filtering method, and the results were compared with those obtained by a hardware-based spatial-filtering method. Computer-based spatial filtering has the important advantage of a capability for tuning the spatial-filter parameters to the target flow.     

Reliability estimation with Weibull inter failure times

In this paper we present three models for the behavior of software failures. By applying these models an attempt has been made to predict reliability growth by predicting failure rates and mean time to next failure of software with Weibull inter failure times at different stages. The changes in the performance of the software as a result of the error removal are described as a Bayes empirical-Bayes prediction in Model I. Model II considers a fully Bayesian analysis with non informative priority of Weibull parameters. An approximation due to Lindley is used in this model as the expressions do not appear in close forms. The M.L. approach is used in Model III. Finally we apply these three models to actual failure data and compare their predictive performances. The comparison of the proposed models is also made in terms of the ratio of likelihoods of observed values based on their predictive distributions.

Among these three models, Model I seems to be quite reasonable as it shows higher reliability growth in all stages. It is noted that this model may be useful to measure the current reliability at any particular stage of the testing process and viewed as a measure of software quality.     

Differences in interferon alpha and beta signaling. Interferon beta selectively induces the interaction of the alpha and betaL subunits of the type I interferon receptor

All Type I interferons (IFNalpha, IFNbeta, IFNomega) bind to the Type I IFN receptor (IFNR) and elicit a common set of signaling events, including activation of the Jak/Stat and IRS pathways. However, IFNbeta selectively induces the association of the alpha subunit of the Type I IFNR with p100, a tyrosyl phosphoprotein, to transduce IFNbeta-specific signals. Using antibodies raised against the different components of the Type I IFNR, we identified p100 as the long form of the beta subunit (betaL subunit) of the Type I IFNR. This was also confirmed in experiments with mouse L-929 cells transfected with truncated forms of betaL. Thus, IFNbeta stimulation of human cells or mouse L-929 transfectants expressing the human alpha and betaL subunits, selectively induces the formation of a signaling complex containing the alpha and betaL subunits of the receptor. The IFNbeta-regulated interaction of the alpha and betaL chains is rapid and transient and follows a similar time course with the tyrosine phosphorylation of these receptor components. These data demonstrate that the signaling specificity for different Type I IFNs is established early in the signaling cascade, at the receptor level, and results from distinct interactions between components of the Type I IFNR.     

A case study and troubleshooting experience of safety power channel of instrumentation and control system of the BAEC TRIGA Research Reactor

Microsystem Technologies - Bangladesh Atomic Energy Commission TRIGA Research Reactor (BTRR) is a MK II type nuclear research reactor with a maximum thermal output power of 3 MW. Nuclear...     

Edge preservation of impulse noise filtered images by improved anisotropic diffusion

This paper provides a robust scheme for random valued impulsive noise reduction along with edge preservation by anisotropic diffusion with improved diffusivity. The defective impulse noisy pixels are detected by Laplacian based second order pixel difference operation where these defective pixels are replaced by appropriate values with regard of the gray level of their four directional neighbors. This de-noised image undergoes the diffusion operation where diffusion coefficient function is modified to make it adaptive by incorporating local gray level variance information. The proposed modified diffusion scheme effectively restore the edges and fine details destroyed during impulse noise reduction process. The effect of proposed diffusion scheme has been studied on various images and the results are compared with some existing diffusion methods which are independently used for impulse noise reduction and edge preservation. The results shows that the prior removal of impulsive noise before the application of diffusion process is advantageous over the direct application of diffusion for removing the impulsive noise. In addition, the results of the proposed diffusion scheme are compared with some of the median filter based methods which are effectively used for impulse noise reduction without caring of edge preservation. The proposed diffusion scheme sufficiently preserves the edges without boosting of impulsive noise components on images corrupted up to 50 % of the impulsive noise density.     

Mouth tracking for hands-free robot control systems

In this paper, we propose a mouth tracking method for remote robot control systems. The main idea behind the work is to help disabled people, who cannot operate any keyboard or joystick, to control a robot without use of their hands. The mouth tracking method is mainly based on the AdaBoost feature detection approach. By adding new Haar-like features for detecting the corner of the mouth, the speed and accuracy of detection are improved. The AdaBoost feature detection combined with the Kalman filter accomplished continuous and accurate mouth tracking. Meanwhile, the gripping commands for the robot manipulator were obtained through recognition of mouth shape, such as for a pouting mouth or a grinning mouth. To assess the validity of the method, mouth detection experiments and robot cargo transport experiments were conducted. The results indicate that the proposed method can realize mouth tracking and robot operations that are quick and accurate in retrieving items successfully.     

Preparation of phenylboronic acid-based hydrogel microneedle patches for glucose-dependent insulin delivery

There is a problem with directly loading insulin into the polymerized glucose-responsive microneedle (MN) patch due to that polymerization conditions and solvents may damage the activity of insulin. In this study, we report a totally polymerized phenylboronic acid-based MN patch, and insulin was directly loaded in MNs by a mild drop/dry procedure. MN patch was prepared by copolymerization of N-isopropyl acrylamide, N-vinyl-2-pyrrolidone, and 3-acrylamidoephenylboronic acid in MN mold. The MN patch showed good glucose-dependent swelling behavior in pH 9.0 at 27°C. After insulin loading procedure, insulin was distributed on and within the MNs. About 43.2% of total insulin was diffused into MNs' interior. As a result, the release of insulin on MNs' surface was uncontrolled by MNs and rapidly finished after ~10 min. However, the release of insulin within MNs was depended on glucose concentration, and insulin was released 1.6 times more at 4 g/L than at 1 g/L glucose concentration after 12 h. Although further improvements are needed to make MN patch responding in physiological environment, this work suggests a solution for directly loading insulin in polymerized glucose-responsive MNs.     

A rapid method for the preparation of silica-coated ZrO2 nanoparticles by microwave irradiation

A novel synthesis of silica-coated ZrO₂ nanoparticles is reported based on microwave irradiation (MW) method. The synthesis of silica-coated ZrO₂ nanoparticles was realized by a rapid uniform hydrolysis and subsequent copolymerization of the precursor tetraethoxysilane (TEOS) on ZrO₂ surface. One of the advantages of this MW irradiation method is the very short coating time and uniform heating in comparison to the conventional ones, allowing the synthesis of uniformly coated ZrO₂ nanoparticles with silica. The XPS analysis revealed the shifts in binding energies for Zr 3d5/2 and Zr 3d3/2 peaks after coating confirming the formation of silica layer on the surface of ZrO₂ nanoparticles. Characteristic silica peaks were observed in the FTIR spectra of coated nanoparticles. The shift in the isoelectric point measured by dynamic light scattering method was indicator of silica coverage of the ZrO₂ surface. The coatings formed at 70 °C were thin and uniform and extended up to 2 nm from the ZrO₂ surface as confirmed by the HR-TEM images.     

Extremely oriented tunicin whiskers in poly(vinyl alcohol) nanocomposites

In order to utilize the excellent mechanical properties of cellulose whiskers (CWs) along their length, the present work was undertaken to embed CWs with highly oriented forms in a polymer matrix. Nanocomposite fibers were prepared using poly(vinyl alcohol) (PVA; degree of polymerization of 1500) as the matrix and a stable aqueous suspension of CWs extracted from tunicates as the reinforcing phase. Macroscopically homogeneous suspensions of PVA–CW were gel‐spun in a methanol coagulating bath. The as‐spun fibers included CWs oriented along the fiber axis and showed a significant increase in dynamic storage modulus. Hot drawing of the PVA–CW as‐spun fibers to their maximal draw ratio led to extremely high orientation of the CWs together with a drastic reduction in voids in the fiber matrix. Outstanding mechanical properties of the drawn composites were obtained by the incorporation of only a small amount (1 wt% of solid PVA content) of CWs. The stress transfer mechanism in the fibers was studied using an X‐ray diffraction technique by applying stress to the whole composite with in situ monitoring of stress on the incorporated CWs. The applied external stress was found to be translated efficiently to the incorporated CWs through the PVA matrix, suggesting strong interfacial bonding between filler and matrix. The strong interaction and efficient stress transfer between matrix and filler are suggested as the cause for the observed improvements in mechanical properties of the composites. Copyright © 2011 Society of Chemical Industry     

Surfactant-Mediated Catalytic Determination of Fe(II) in Herbal and Pharmaceutical Products

In the present work, the catalyzed oxidation of neutral red (NR) by bromate was used to work out a kinetic-based analytical method as an alternative technique for the determination of Fe(II) in real and synthetic samples. A use of a surfactant, N-dodecylpyridinium chloride enhanced the sensitivity of the reaction by becoming involved in the reaction mechanism and providing a more suitable reaction environment. The iron-catalyzed oxidation of NR with potassium bromate was studied kinetically by using a fixed time method. The reaction was followed by measuring the decrease in absorbance at 535 nm. The use of a surfactant in the analytical run showed a five times increase in the sensitivity of the method. It served as a ready reservoir of NR by increasing its solubilization. The salt effect, pH, and reagent concentration were also investigated to achieve a more selective and sensitive analytical procedure. Under optimized conditions (4.2 × 10⁻⁵ mol L⁻¹ NR, 1.4 × 10⁻³ mol L⁻¹ KBrO₃, 1.5 × 10⁻² mol L⁻¹ cationic surfactant, 0.5 mol L⁻¹ LiCl and pH 2.60 at 30 °C), iron(II) was determined in the range 0.1–0.5 μg mL⁻¹ with a detection limit of 0.019 μg mL⁻¹ and a relative standard deviation (n = 6) 1.02% for 0.2 μg mL⁻¹ Fe(II). The influence of foreign ions on the accuracy of the results was investigated. The developed method is extremely sensitive, selective and simple. The method was applied successfully to the determination of iron in the herbal pharmaceutical and synthetic samples. The results showed good agreement with those obtained by atomic absorption spectrophotometry.