Fault Detection,Diagnosis and Prediction in Electrical Valves Using Self-Organizing Maps

This paper presents a proactive maintenance scheme for fault detection, diagnosis and prediction in electrical valves. The proposed scheme is validated with a case study, considering a specific valve used for controlling the oil flow in a distribution network. The scheme is based in self-organizing maps, which perform fault detection and diagnosis, and temporal self-organizing maps for fault prediction. The adopted fault model considers deviations either in torque, in the valve’s gate position or in the opening or closing time. The map which performs the fault detection, diagnosis and prediction, is trained with the energy spectral density information, obtained from the torque and position signals by applying the wavelet packet transform. These signals are provided by a mathematical model devised for the electrical valve. The training is performed by fault injection based on parameter deviations over this same mathematical model. The proposed system is embedded into an FPGA-based platform. Experimental results demonstrate the effectiveness of the proposed approaches.     

Effect of Disinfection on Adhesion of Reline Polymers

Cylinders (3.5 × 5.0 mm) of the reline resins Kooliner (K), New Truliner (N), Tokuso Rebase Fast (T), and Ufi Gel Hard (U) were bonded to cylinders (20 × 20 mm) of the denture base resin Lucitone 550 (L), and samples were divided into two controls and four test groups (n = 8). Shear tests (0.5 mm/min) were performed after polymerization or immersion in water (37°C) for 7 days (controls); two or seven cycles of disinfection by immersion in sodium perborate (50°C/10 min) or microwave irradiation (650 W/6 min). Statistical analyses (α = 0.05) revealed that two cycles of microwave and chemical disinfection increased the mean bond strengths of materials T (9.08 to 12.93 MPa) and L (18.89 to 23.02 MPa). For resin L, seven cycles of chemical (15.72 MPa) and microwave (17.82 MPa) disinfection decreased the shear bond strength compared with the respective control (21.74 MPa). Resins U (13.12 MPa), K (8.44 MPa), and N (7.98 MPa) remained unaffected.     

Adaption of user experience questionnaires for different user groups

Universal Access in the Information Society - Products should guarantee a sufficiently high user experience for all intended user groups. A good user experience means not only that it is sufficient...     

Arbuscular Mycorrhizal Fungi and Plant Growth-Promoting Pseudomonads Increases Anthocyanin Concentration in Strawberry Fruits (Fragaria x ananassa var. Selva) in Conditions of Reduced Fertilization

Anthocyanins are a group of common phenolic compounds in plants. They are mainly detected in flowers and fruits, are believed to play different important roles such as in the attraction of animals and seed dispersal, and also in the increase of the antioxidant response in tissues directly or indirectly affected by biotic or abiotic stress factors. As a major group of secondary metabolites in plants commonly consumed as food, they are of importance in both the food industry and human nutrition. It is known that arbuscular mycorrhizal (AM) fungi can influence the plant secondary metabolic pathways such as the synthesis of essential oils in aromatic plants, of secondary metabolites in roots, and increase flavonoid concentration. Plant Growth-Promoting Bacteria (PGPB) are able to increase plant growth, improving plant nutrition and supporting plant development under natural or stressed conditions. Various studies confirmed that a number of bacterial species living on and inside the root system are beneficial for plant growth, yield and crop quality. In this work it is shown that inoculation with AM fungi and/or with selected and tested Pseudomonas strains, under conditions of reduced fertilization, increases anthocyanin concentration in the fruits of strawberry.     

High-frequency asymptotic formulation for prompt response of parabolic reflector antennas

This work presents some important concepts for the temporal characterization of reflector antennas based on the determination of the transient antenna response together with a useful definition of the early-time antenna radiation pattern. The concepts are useful in the analysis and design of reflector antennas intended for high resolution radars and for high capacity digital, and UWB communication systems.     

Simulation of methanol-to-olefin reaction over SAPO-34 catalysts with different particle sizes: Formation of active sites and deactivation

Conversion profiles of methanol-to-olefin (MTO) reaction over SAPO-34 catalysts with different particle sizes were simulated using two kinetic models. The MTO reaction was assumed to consist of three steps: the formation of hexamethylbenzene (HMB), the production of lower olefins over HMB and the further condensation of HMB to polyaromatic hydrocarbons. To reflect the effect of particle size on the MTO reaction, only the space near the external particle surface was considered to be available for HMB formation in Model I, whereas an effectiveness factor and a deactivation function were introduced in Model II. The simulated conversion profiles of the MTO reaction by both models successfully confirmed the presence of an induction period and deactivation, but Model II showed a better agreement between the experimental and simulated results because of its inclusion of the deactivation function and its consideration for the gradient of methanol concentration.     

Application of solvent dye in the field of biodiesel preservation

In this study, biodiesel (OSRB) from degummed oilseed radish oil (OSR) was obtained by transesterification, and the effect on its thermal stability of a binary compound containing a conventional antioxidant and a solvent dye was evaluated. A combination of the traditional antioxidant tert-butylhydroquinone (TBHQ) and a solvent dye, so-called CI Solvent Blue 35 (SB-35), was prepared and incorporated into OSR and OSRB prior to analysis. The acid value, peroxide value, and induction period were measured, and it was found that TBHQ and SB-35 were highly effective in stabilising OSR and OSRB when used in combination. The TBHQ/SB-35 blend had strong antioxidation activity, even at very low concentrations, when compared with the addition of the individual compounds. In summary, the results showed that a TBHQ/SB-35 blend may be successfully used as an alternative additive for improving oil and biodiesel preservation.     

Addition of α‐tocopherol on poly(lactic acid): Thermal,mechanical, and sorption properties

This work investigates the effect of the addition of a well‐known antioxidant, α‐tocopherol in poly (lactic acid) flexural and barrier properties. For that purpose, films of poly(lactic acid) enriched with 0, 2.2, and 4.4% of α‐tocopherol were prepared. Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis were used to characterize the changes in the mechanical and thermal properties. The sorption of oxygen and carbon dioxide in the prepared enriched films of poly(lactic acid) was measured at different temperatures between 283 and 313 K and pressures up to atmospheric pressure using a Quartz Crystal Microbalance. Although no significant changes were found in the mechanical and thermal properties, the addition of α‐tocopherol promotes an increasing in the oxygen sorption and the convex shape of the isotherms indicate a strong interaction gas‐polymer. Regarding the sorption of carbon dioxide, no pronounced effect was found. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The mapping method as a toolbox to analyze,design, and optimize micromixers

The mapping method is employed as an efficient toolbox to analyze, design, and optimize micromixers. A new and simplified formulation of this technique is introduced here and applied to three micromixers: the staggered herringbone micromixer (SHM), the barrier-embedded micromixer (BEM), and the three-dimensional serpentine channel (3D-SC). The mapping method computes a distribution matrix that maps the color concentration distribution from inlet to outlet of a micromixer to characterize mixing in a quantitative way. Once the necessary distribution matrices are obtained, computations are fast and numerous layouts of the mixer are easily evaluated, resulting in an optimal design. This approach is demonstrated using the SHM and the BEM as typical examples. Mixing analysis in the 3D-SC illustrates that also complex flows, for example in the presence of back-flows, can be efficiently dealt with by using the new formulation of the mapping method.     

IN SEARCH OF COAL EFFICIENCY

Micro-wave pretreatment of coals followed by magnetic separation would facilate more effective to combustion. Similarly higher heac release and lesser ash content were observed in the case of coal - oil mixture. This process is more economic than other two processes.