Sliding Mode Controller with Multisensor Data Fusion for Piezo Actuated Structure

The benefits of multisensor data fusion (MSDF) in controlling the piezo actuated beam structure using sliding mode controller (SMC) has been brought out. The first two vibrating modes of the smart cantilever beamare measured by two sensors namely, piezoelectric sensor and laser displacement sensor. The states are estimated from the sensors outputs using information filter, which were then fused and applied as input to the controller. The controller has been designed from the linear dynamic model of a piezo actuated beam, identified using linear recursive least square (RLS) method based on ARX model. A digital control system consisting of virtual instrumentation software LabVIEW, and USB data acquisition module NI 6008, was used for simulation and real-time control. Improved closed-loop performance was obtained when the controller designed used fused data, as compared to the closed-loop performance obtained with a single sensor. The beam structure considered in this work was a pilot model of the structures used in aerospace applications. Simulation and experimental results presented demonstrate the benefits of data fusion in controlling the vibration modes.Defence Science Journal, 2011, 61(4), pp.346-353, DOI:http://dx.doi.org/10.14429/dsj.61.111

Comprehensive User Engagement Sites (CUES) in Philadelphia: A Constructive Proposal

This paper is a study about Philadelphia’s comprehensive user engagement sites (CUESs) as the authors address and examine issues related to the upcoming implementation of a CUES while seeking solutions for its disputed questions and plans. Beginning with the federal drug schedules, the authors visit some of the medical and public health issues vis-à-vis safe injection facilities (SIFs). Insite, a successful Canadian SIF, has been thoroughly researched as it represents a paradigm for which a Philadelphia CUES can expand upon. Also, the existing criticisms against SIFs are revisited while critically unpackaged and responded to in favor of the establishment. In the main section, the authors propose the layout and services of the upcoming CUES, much of which would be in congruent to Vancouver’s Insite. On the other hand, the CUES would be distinct from Insite, as the authors emphasize, in that it will offer an information center run by individuals in recovery and place additional emphasis on early education for young healthcare professionals by providing them a platform to work at the site. The paper will also briefly investigate the implementation of a CUES site under an ethical scope of the Harm Reduction Theory. Lastly, the authors recommend some strategic plans that the Philadelphia City government may consider employing at this crucial stage

Efficiency of single and di- site phase transfer catalyzed polymerization of glycidyl methacrylate in the two-phase system: A kinetic study

In the present kinetic study, glycidyl methacrylate has been polymerized using synthesized single-site phase transfer catalyst - 2-benzoylethyldecyldimethylammonium bromide and di-site –phase transfer catalyst -1,1,4,4-tetramethyl-1,4 dioctylethylenediammonium bromide along with potassium peroxydisulfate as the initiator in inert medium and at a constant temperature of 60°C. The effect of concentrations of the monomer, initiator, catalyst, ionic strength, pH and solvent polarity on the rate of polymerization has been examined. The order with respect to the monomer, initiator, and phase transfer catalyst was found to be 1, 0.5, and 0.5, respectively. A suitable polymerization mechanism is proposed. Ionic strength and pH has no impact on the rate of polymerization. It is observed that, as the solvent's polarity increased, the rate of polymerization also increased. Di-site phase transfer catalyst results in a higher rate of polymerization compared with single-site phase transfer catalyst while polymerizing glycidyl methacrylate

Corrosion inhibition efficiency of newly synthesized quaternary ammonium salt in 1M HCl

68-74The newly synthesized quaternary ammonium salt, 1, 4-Bis (dimethyl decyl) ethylene diammonium bromide has been characterized by FT-IR, 1H NMR, 13C NMR. It has been examined for its corrosion efficiency by the weight loss method by immersing in a 1M HCl solution. The surface morphology is characterized using Scanning Electron Microscopy and it exhibited the variation between corroded surface and inhibited surface of carbon steel.Energy-Dispersive X-ray spectroscopy also shown the differences in composition of the corroded and surface coated with inhibitor. The efficiency of the inhibitor is investigated by varying the concentration of the inhibitor from 100 to 500 ppm and over a temperature range from 25 to 45C. Inhibitor efficiency is maximum in the concentration range of 500 ppm and found to be 77.75% at 45C. The plot of concentration against surface coverage revealed that, the present system follows Langmuir’s adsorption isotherm. Compared to acidic medium, inhibitor excelled its maximum efficiency in the neutral medium

Efficiency of single and di- site phase transfer catalyzed polymerization of glycidyl methacrylate in the two-phase system: A kinetic study

445-452In the present kinetic study, glycidyl methacrylate has been polymerized using synthesized single-site phase transfer catalyst - 2-benzoylethyldecyldimethylammonium bromide and di-site –phase transfer catalyst -1,1,4,4-tetramethyl-1,4 dioctylethylenediammonium bromide along with potassium peroxydisulfate as the initiator in inert medium and at a constant temperature of 60°C. The effect of concentrations of the monomer, initiator, catalyst, ionic strength, pH and solvent polarity on the rate of polymerization has been examined. The order with respect to the monomer, initiator, and phase transfer catalyst was found to be 1, 0.5, and 0.5, respectively. A suitable polymerization mechanism is proposed. Ionic strength and pH has no impact on the rate of polymerization. It is observed that, as the solvent's polarity increased, the rate of polymerization also increased. Di-site phase transfer catalyst results in a higher rate of polymerization compared with single-site phase transfer catalyst while polymerizing glycidyl methacrylate

24-Hour Measurement of Gastric pH in Rural South Africa

Background. Previous studies have established norms of 24-hour gastric pH profiles for western countries. This study was designed to establish the pattern for a rural African population with a high incidence of oesophageal cancer. Methods. After lower oesophageal manometry a probe was placed 10 cm distal to the lower oesophageal sphincter. We carried out 24-hour ambulatory monitoring of gastric pH on 59 healthy subjects. This was satisfactorily completed on 26 female and 18 male (age 21–64, median 35) subjects in the Transkei region of South Africa. Results. The mean 24 hour gastric pH was 2.84 and the mean night-time pH was 3.7. 40 volunteers recorded a night-time pH reaching over 4. 33 volunteers recorded a night-time pH over 7. Night-time alkalinisation was present for 136.4 minutes (25th centile 22.8, 75th centile 208.1) at pH4 or over, and 79.3 (2.5, 122.7) minutes at pH7 or over. Episodes of rapid alkaline rise were 17 (10, 47). 21.1% of these occurred while supine. 35 of 36 tested subjects were positive for H. pylori IgG. Conclusion. Gastric alkalinisation is common in Transkei, at a higher pH than that reported in other studies, and is sustained longer. Nighttime alkalinisation is frequent. This suggests a high level of duodenogastric reflux

High energy X-γ ray spectrometer on the Chandrayaan-1 mission to the Moon

The Chandrayaan-1 mission to the Moon scheduled for launch in late 2007 will include a high energy X-ray spectrometer (HEX) for detection of naturally occurring emissions from the lunar surface due to radioactive decay of the 238U and 232Th series nuclides in the energy region 20-250 keV. The primary science objective is to study the transport of volatiles on the lunar surface by detection of the 46.5 keV line from radioactive 210Pb, a decay product of the gaseous 222Rn, both of which are members of the 238U decay series. Mapping of U and Th concentration over the lunar surface, particularly in the polar and U-Th rich regions will also be attempted through detection of prominent lines from the U and Th decay series in the above energy range. The low signal strengths of these emissions require a detector with high sensitivity and good energy resolution. Pixelated Cadmium-Zinc-Telluride (CZT) array detectors having these characteristics will be used in this experiment. Here we describe the science considerations that led to this experiment, anticipated flux and background (lunar continuum), the choice of detectors, the proposed payload configuration and plans for its realizatio

LRP5 Is Required for Vascular Development in Deeper Layers of the Retina

Background: The low-density lipoprotein receptor-related protein 5 (LRP5) plays an important role in the development of retinal vasculature. LRP5 loss-of-function mutations cause incomplete development of retinal vessel network in humans as well as in mice. To understand the underlying mechanism for how LRP5 mutations lead to retinal vascular abnormalities, we have determined the retinal cell types that express LRP5 and investigated specific molecular and cellular functions that may be regulated by LRP5 signaling in the retina. Methods and Findings: We characterized the development of retinal vasculature in LRP5 mutant mice using specific retinal cell makers and a GFP transgene expressed in retinal endothelial cells. Our data revealed that retinal vascular endothelial cells predominantly formed cell clusters in the inner-plexiform layer of LRP5 mutant retina rather than sprouting out or migrating into deeper layers to form normal vascular network in the retina. The IRES-b-galactosidase (LacZ) report gene under the control of the endogenous LRP5 promoter was highly expressed in Müller cells and was also weakly detected in endothelial cells of the retinal surface vasculature. Moreover, the LRP5 mutant mice had a reduction of a Müller cell-specific glutamine transporter, Slc38a5, and showed a decrease in b-wave amplitude of electroretinogram. Conclusions: LRP5 is not only essential for vascular endothelial cells to sprout, migrate and/or anastomose in the deeper plexus during retinal vasculature development but is also important for the functions of Müller cells and retina