21 research outputs found

    Static and free vibration analyses of laminated composite shells by cell-based smoothed discrete shear gap method (CS-DSG3) using three-node triangular elements

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    A cell-based smoothed discrete shear gap method (CS-DSG3) using three-node triangular elements was recently proposed to improve the performance of the discrete shear gap method (DSG3) for static and free vibration analyses of isotropic Reissner-Mindlin plates and shells. In this paper, the CS-DSG3 is further extended for static and free vibration analyses of laminated composite shells. In the present method, the first-order shear deformation theory (FSDT) is used in the formulation due to the simplicity and computational efficiency. The accuracy and reliability of the proposed method are verified by comparing its numerical solutions with those of others available numerical results

    Plant-based carotenoid supplementation: Growth, feed utilization efficiency, and coloration in false clownfish (<em>Amphiprion ocellaris</em>)

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    The false clownfish (Amphiprion ocellaris) is a prominent species in the marine ornamental trade, valued for its vibrant orange-red coloration. However, aquaculture-bred individuals often exhibit less intense coloration than their wild counterparts, presenting a challenge for both breeders and aquarists. This study evaluates the effects of carotenoid-enriched diets, sourced from natural ingredients such as pumpkin, bell pepper, carrot, and gac, as well as a synthetic source like astaxanthin, on the coloration and growth of false clownfish. In a controlled experiment, juvenile fish with an initial average length of 3.21 ± 0.03 cm and weight of 0.61 ± 0.02 g were allocated to 60-liter tanks and fed the experimental diets over a 75-day trial period. Carotenoid supplementation was standardized at 250 mg/kg across diets, with a control group receiving no added carotenoids. The experimental design was completely randomized, involving three replicates per dietary treatment. The results indicated that diets supplemented with gac and bell pepper significantly enhanced growth and feed efficiency (p < 0.05). Notably, the skin redness intensity (a* value) was increased by 75.73% in the gac-supplemented group, 89.20% in the bell pepper group, and 91.99% in the astaxanthin group, relative to the control (p < 0.05). Additionally, carotenoid deposition in the integument was significantly higher in all supplemented groups, with an increase of 83.74% in the astaxanthin group, 89.59% in the gac group, and 98.43% in the bell pepper group, compared to the control (p < 0.05). These findings suggest that natural carotenoids, particularly from gac and bell pepper, can be effective alternatives to synthetic astaxanthin, potentially improving the attractiveness and commercial value of captive-bred false clownfish and alleviating the exploitation of wild populations

    Highly dispersed pt nanoparticles on the novel ti0.7w0.3o2 support using the rapid microwave-assisted polyol route

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    Mesoporous Ti0.7W0.3O2 nanoparticles, being in anatase TiO2 phase, possessed a uniform morphology of spherical nanoparticles of 10 nm diameter with the high surface area up to 201.481 m2/g, which is closely similar to the surface area of common commercial carbon blacks. More importantly, the electrical conductivity of Ti0.7W0.3O2 was found to be 0.022 S/cm, which is ~ 1.0x105-fold higher than that of undoped-TiO2 (1.37x10-7 S/cm). The increase in electrical conductivity of Ti0.7W0.3O2 may attribute to the successful incorporation of tungsten(VI) ions into TiO2 lattices, subsequently resulting in n-type doping and generating more free electrons acted as charge carriers. The Pt/Ti0.7W0.3O2 catalyst also was synthesized via the rapid microwave-assisted polyol route at 160 C for 4 min with the power of 240

    Evaluating the Motor Imagery Classification Performance of a Double-Layered Feature Selection on Two Different-Sized Datasets

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    Numerous investigations have been conducted to enhance the motor imagery-based brain–computer interface (BCI) classification performance on various aspects. However, there are limited studies comparing their proposed feature selection framework performance on both objective and subjective datasets. Therefore, this study aims to provide a novel framework that combines spatial filters at various frequency bands with double-layered feature selection and evaluates it on published and self-acquired datasets. Electroencephalography (EEG) data are preprocessed and decomposed into multiple frequency sub-bands, whose features are then extracted, calculated, and ranked based on Fisher’s ratio and minimum-redundancy-maximum-relevance (mRmR) algorithm. Informative filter banks are chosen for optimal classification by linear discriminative analysis (LDA). The results of the study, firstly, show that the proposed method is comparable to other conventional methods through accuracy and F1-score. The study also found that hand vs. feet classification is more discriminable than left vs. right hand (4–10% difference). Lastly, the performance of the filter banks common spatial pattern (FBCSP, without feature selection) algorithm is found to be significantly lower (p = 0.0029, p = 0.0015, and p = 0.0008) compared to that of the proposed method when applied to small-sized data

    Electrical and Structural Properties of All-Sputtered Al/SiO2/p-GaN MOS Schottky Diode

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    The all-sputtered Al/SiO2/p-GaN metal-oxide-semiconductor (MOS) Schottky diode was fabricated by the cost-effective radio-frequency sputtering technique with a cermet target at 400 &deg;C. Using scanning electron microscope (SEM), the thicknesses of the electrodes, insulator SiO2 layer, and p-GaN were found to be ~250 nm, 70 nm, and 1 &micro;m, respectively. By Hall measurement of a p-Mg-GaN film on an SiO2/Si (100) substrate at room temperature, the hole&rsquo;s concentration (Np) and carrier mobility (&mu;) were found to be Np = 4.32 &times; 1016 cm&minus;3 and &mu; = 7.52 cm2&middot;V&minus;1&middot;s&minus;1, respectively. The atomic force microscope (AFM) results showed that the surface topography of the p-GaN film had smoother, smaller grains with a root-mean-square (rms) roughness of 3.27 nm. By I&ndash;V measurements at room temperature (RT), the electrical properties of the diode had a leakage current of ~4.49 &times; 10&minus;8 A at &minus;1 V, a breakdown voltage of &minus;6 V, a turn-on voltage of ~2.1 V, and a Schottky barrier height (SBH) of 0.67 eV. By C&ndash;V measurement at RT, with a frequency range of 100&ndash;1000 KHz, the concentration of the diode&rsquo;s hole increased from 3.92 &times; 1016 cm&minus;3 at 100 kHz to 5.36 &times; 1016 cm&minus;3 at 1 MHz, while the Fermi level decreased slightly from 0.109 to 0.099 eV. The SBH of the diode at RT in the C&ndash;V test was higher than in the I&ndash;V test because of the induced charges by dielectric layer. In addition, the ideality factor (n) and series resistance (Rs) determined by Cheung&rsquo;s and Norde&rsquo;s methods, other parameters for MOS diodes were also calculated by C&ndash;V measurement at different frequencies
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