Evaluation of lubricant condition and engine health based on soft computing methods

Neural Computing and Applications - Evaluating the condition of the lubricant plays an influential role in the maintenance engineering of mechanical systems. This study has several objectives and...     

Investigation the Al–Fe–Cr–Ti nano composites structures with using XRD and AFM techniques

The performance of multilayers has been widely investigated in metal/metal systems. Shrinking this system down to less than 10 nm dislocation blocking occurs. We should thus try to find a way to get a structure with less dislocation, and/or strain because low diffusivity ultra high vacuum chamber is the basic requirements for growing ultra thin films and nano scale materials. We used William–Hall relation based on Scherr equation in X-ray powder spectrum and drawn the stress–strain diagrams. It shows that Al–Fe–Cr–Ti composites have very low diffusivity and equilibrium solubility in Al (0.05 at.% Fe, >0.02 at.% Cr, and >0.3 at.% Ti). Al–Ti–Fe–Cr composite powders have also been prepared from sol–gel method starting from elemental powders at both ambient and elevated temperatures. The obtained results from XRD (X-ray Diffraction), AFM (Atomic Force Microscopy) and X-ray powder techniques indicate that nano-grains with 0.03 at %Cr can cause a reduction of leakage current through the SS chamber due to its amorphous structure.     

Reduction the leakage current through povidone-SiO<Subscript>2</Subscript> nano-composite as a promising gate dielectric of FETs

In the present study, povidone-SiO₂ nano-composite dielectric film was introduced to replace SiO₂ gate dielectric film. The organic and inorganic particles homogeneously dispersed in nano-composite film. The structure of nano-composite film was affected by annealing temperatures. By increase in annealing temperature up to 200?°C, wt% of carbon, oxygen and nitrogen increased and wt% of silicon decreased. At 240?°C, the organic phase desorbed and nano-composite structure degraded. The annealing temperature of 150?°C was suitable for adhesion between two phases. The cross-linked structure of dielectric film annealed at 150?°C led to decrease in leakage current.     

Thermal stability of processed PVC/bamboo blends: effect of compounding procedures

Polyvinyl chloride (PVC) was mixed with bamboo (Bambusa vulgaris) particle and additives by using PVC composite manufacturing system including initial dry blending with hot-cool mixing, followed by granulation via counter-rotating extrusion, and then consolidation by compression moulding to produce compression moulded board (CMB). The effects of different bamboo particle size (75 µm and 1 mm), bamboo particle loading (25 and 50% loading ratio), and differing processing lubricants content level (compositions 1 and 2) on the thermal stability of the composites were determined. Results show no significant trends in glass transition temperature (T_g) between dry blends, granules, and CMB, and between B. vulgaris particle loading at the respective processing steps. For samples with higher lubricant contents, the PVC T_g was observed to decrease up to 5?°C, possibly due to the reduced melt viscosity. The thermal decomposition temperature at 5% mass loss (T_?5%) appeared to decrease from dry blend to CMB due to sample degradation on further processing at higher temperatures. The use of 50% B. vulgaris particle loading also reduced the T_?5% values, assignable to bamboo particle degradation caused by the high processing temperatures. For oxidative induction time (OIT) testing, only granules and CMB from pure PVC composites system showed measurable oxidative times compared with OIT profiles of PVC/B. vulgaris composites system, suggestive of comparatively stabilized thermoplastic composites. This revealed that processing with bamboo particles does not contribute to degradation of PVC composites.     

Spectrophotometric and chemometric studies on the simultaneous determination of two benzodiazepines in human plasma

A numerical simple, accurate and precise method based on spectrophotometric data coupled with multivariate calibration methods, PLS and MLR, combined with GA was developed for the simultaneous determination of two benzodiazepines, Clobazam and Flurazepam. A data set of absorption spectra obtained from a calibration set of mixtures containing the compounds was used to build GA-PLS and GA-MLR models. The models were tested using a dataset constructed from the compound synthetic solutions. The better model was also applied to plasma samples. The proposed method requires no preliminary separation steps and can be used for these drugs analysis in quality control laboratories.     

Structural and Electrical Properties of Ta ax La(1−a)x O y Thin Films

Effect of annealing temperature on the characteristics of sol–gel-driven Ta _ax La_(1?a)x O _y thin film spin-coated on Si substrate as a high-k gate dielectric was studied. Ta _ax La_(1?a)x O _y thin films with different amounts of a were prepared (as-prepared samples). X-ray diffraction measurements of the as-prepared samples indicated that Ta_0.3x La_0.7x O_y film had an amorphous structure. Therefore, Ta_0.3x La_0.7x O _y film was chosen to continue the present studies. The morphology of Ta_0.3x La_0.7x O _y films was studied using scanning electron microscopy and atomic force microscopy techniques. The obtained results showed that the size of grain boundaries on Ta_0.3x La_0.7x O _y film surfaces was increased with increasing annealing temperature. Electrical and optical characterizations of the as-prepared and annealed films were investigated as a function of annealing temperature using capacitance–voltage (C–V) and current density–voltage (J–V) measurements and the Tauc method. The obtained results demonstrated that Ta_0.3x La_0.7x O _y films had high dielectric constant (≈27), wide band gap (≈4.5 eV), and low leakage current density (≈10^?6 A/cm² at 1 V).