Cubic millimeter power inductor fabricated in batch-type wafer technology

A hybrid technology for the realization of three-dimensional (3-D) miniaturized power inductors is presented. Our devices consist of planar Cu coils on polyimide substrates, and mm-size ferrite magnetic cores, obtained by three-dimensional micro-patterning of ferrite wafers using powder blasting. The coils are realized using an in-house developed high-resolution polyimide spinning and Cu electroplating process. Winding widths down to 5 /spl mu/m have been obtained and total device volumes are ranging between 1.5 and 10 mm/sup 3/. Inductive and resistive properties are characterized as a function of frequency; inductance values in the 100 /spl mu/H range have been obtained.     

Corrosion protection of iron by polypyrrole modified by copper using the cementation process

Polypyrrole (PPy) coatings have been deposited on iron from aqueous oxalic acid solution at different current densities. The polymer deposit obtained at a current density of 2 mA cm⁻² yields strongly adherent and smooth PPy layers. The modification of the film by incorporation of copper microparticles using the cementation process was applied. The resulting PPy/Cu film electrodes were characterized by scanning electron microscopy and EDX analysis. The protective performance against corrosion of these films is evaluated by using open circuit potential monitoring in highly corrosive solution (3% NaCl + HCl, pH 1). The results obtained were promising in the protection against corrosion.     

Preparation on iron of a polypyrrole (PPy) electrode modified with copper by the electrochemical cementation process

Conducting polypyrrole electrodes obtained under galvanostatic electropolymerization on iron from aqueous solutions of pyrrole and oxalic acid were modified with copper particles using the electrochemical cementation process. The electrochemical response of these modified electrodes was compared to that of the unmodified polymer electrode and also to that of bare metallic copper. The modified polypyrrole electrode showed noticeable enhancement for the rate of proton reduction.     

Soluble conducting poly(aniline-co-orthotoluidine) copolymer as corrosion inhibitor for carbon steel in 3% NaCl solution

The copolymer poly (aniline-co-o-toluidine) noted poly(ANI-co-OT) is chemically synthesized, and characterized by FT-IR, UV-Vis, TGA and XRD techniques. The results show that this copolymer presents new structures and it is more thermally stable than the corresponding parent homopolymers. It is found that it is soluble in dimethylformamide (DMF), while the homopolymers have a low solubility. Techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) have been employed to study the inhibition effects of this copolymer on the corrosion of carbon steel in 3% NaCl solution. The results show an increase in inhibition efficiency as a function of copolymer concentration to attain an optimum (70%) for a concentration close to 100 ppm. This is due to the higher coverage of the carbon steel electrode surface as shown by the Temkin adsorption isotherm. The Potentiodynamic polarisation studies reveal that this copolymer acts as a mixed-type inhibitor. The results obtained by potentiodynamic and EIS techniques are in good agreement.     

Measurement of the adsorptive capacity of a powder

The purpose of this work was to recommend a method of measuring the adsorptive capacity of powdered activated carbon (PAC). The adsorptive capacity is needed in future mathematical models of dispersed phase adsorption. This measurement was difficult, because the large drag forces in powders resist any flow into the sample volume, causing big pressure gradients.

Two approaches were tested and compared; a material balance over a packed bed, and a standard volumetric method. The pressure loss across the packed bed was made small by the combination of the PAC with glass ballotini. Toluene was chosen as a sorbate because of its ease of measurement.

The results concerned pressure variations in the packed bed, and the ease with which the end-points could be found in either method. With regard to the packed bed, the time from the start of breakthrough to saturation was typically 110 min. The principal reason for this delay was channelling; the breakthrough curve could not be used to infer pore diffusion coefficients. The total pressure within the bed was kept to within 5% of its mean value. Hence, the adsorptive capacity could be plotted as a function of pressure, and fitted with a Freundlich isotherm with an exponent of n=0.2. Including the PAC, the adsorptive capacities of four kinds of carbon, at the same temperature and pressure, varied from 8 to 16%.

For the volumetric method, at least 3 h were needed for the sorbent and sorbate to reach equilibrium. A mathematical model showed that the uptake curve was controlled by heat transfer. Because the test volume was under a partial vacuum, the technician had to be careful that no air leaked into it during the test. The volumetric method was faster with 250 μm diameter carbon granules; the end-point was evident after 20 min.

In conclusion, a method involving a packed bed was developed to measure the adsorptive capacity of a powder. The end-point was determined easily; the end-point for the volumetric method was indistinct.     

A vehicle plate recognition system based on deep learning algorithms

Multimedia Tools and Applications - In modern life, the massive number of vehicles makes it hard for a human being to process its related information. So, it is important to build an automatic...     

An efficient hardware implementation of parallel EBCOT algorithm for JPEG 2000

With the augmentation in multimedia technology, demand for high-speed real-time image compression systems has also increased. JPEG 2000 still image compression standard is developed to accommodate such application requirements. Embedded block coding with optimal truncation (EBCOT) is an essential and computationally very demanding part of the compression process of JPEG 2000 image compression standard. Various applications, such as satellite imagery, medical imaging, digital cinema, and others, require high speed and performance EBCOT architecture. In JPEG 2000 standard, the context formation block of EBCOT tier-1 contains high complexity computation and also becomes the bottleneck in this system. In this paper, we propose a fast and efficient VLSI hardware architecture design of context formation for EBCOT tier-1. A high-speed parallel bit-plane coding (BPC) hardware architecture for the EBCOT module in JPEG 2000 is proposed and implemented. Experimental results show that our design outperforms well-known techniques with respect to the processing time. It can reach 70 % reduction when compared to bit plane sequential processing.     

The Open State Selectivity of the Bean Seed VDAC Depends on Stigmasterol and Ion Concentration

The voltage-dependent anion channel (VDAC) is the major pathway for metabolites and ions transport through the mitochondrial outer membrane. It can regulate the flow of solutes by switching to a low conductance state correlated with a selectivity reversal, or by a selectivity inversion of its open state. The later one was observed in non-plant VDACs and is poorly characterized. We aim at investigating the selectivity inversion of the open state using plant VDAC purified from Phaseolus coccineus (PcVDAC) to evaluate its physiological role. Our main findings are: (1) The VDAC selectivity inversion of the open state occurs in PcVDAC, (2) Ion concentration and stigmasterol affect the occurrence of the open state selectivity inversion and stigmasterol appears to interact directly with PcVDAC. Interestingly, electrophysiological data concerning the selectivity inversion of the PcVDAC open state suggests that the phenomenon probably does not have a significant physiological effect in vivo.     

Re-examination of the β→γ transformation of Ca2SiO4

Dicalcium silicate finds applications in different fields (cement, bio-ceramics, refractories). In the case of Portland cement, its interest is its lower sintering temperature compared to tricalcium silicate and therefore an interesting compound for low CO₂ cements. Dicalcium silicate goes through different polymorphic forms, namely α, α'_H, α'_L, β and γ, as the temperature decreases. In theory, only the γ-phase is stable at room temperature. In a polycrystalline material, the different polymorphs can co-exist depending on several factors (sintering conditions, presence of impurities, grain size) and the interpretations given in the literature are sometimes contradictory. For cement applications, only the α, α' or β polymorphs react with water to give hydrates while γ does not. Therefore, this paper focuses specifically on the effect of grain size on the β to γ transformation. We also propose that the transformation is semi-reconstructive and not martensitic as suggested by some authors.