Metallurgical Investigation of the Collapsed Front Structure of a Dragline in a Coal Mine

Journal of Failure Analysis and Prevention - A dragline is the largest mobile equipment on earth, and it is called the “kingpin” of any mine site. In this present investigation, a case...     

Evaluating the Efficiency of CBAM-Resnet Using Malaysian Sign Language

The deaf-mutes population is constantly feeling helpless when others do not understand them and vice versa. To fill this gap, this study implements a CNN-based neural network, Convolutional Based Attention Module (CBAM), to recognise Malaysian Sign Language (MSL) in videos recognition. This study has created 2071 videos for 19 dynamic signs. Two different experiments were conducted for dynamic signs, using CBAM-3DResNet implementing ‘Within Blocks’ and ‘Before Classifier’ methods. Various metrics such as the accuracy, loss, precision, recall, F1-score, confusion matrix, and training time were recorded to evaluate the models’ efficiency. Results showed that CBAM-ResNet models had good performances in videos recognition tasks, with recognition rates of over 90% with little variations. CBAM-ResNet ‘Before Classifier’ is more efficient than ‘Within Blocks’ models of CBAM-ResNet. All experiment results indicated the CBAM-ResNet ‘Before Classifier’ efficiency in recognising Malaysian Sign Language and its worth of future research.     

Fuzzy Decision Model: Evaluating and Selecting Open Banking Business Partners

The finance supply chain has always been a different supply chain compared to product supply chain being a service supply chain. Open Banking (OB) is one of the most important milestones since the beginning of financial technology innovation and service supply chain. As these are activities provided by traditional banks, non-bank financial institutions also provide financial service with access to consumer banking, transactional and other financial data to develop financial applications and services tailored to their customers. The development of financial technology, “Open banking”, promotes financial services to begin this transformation. However, evaluating and selecting open banking business partners from multiple perspectives for banks are underexplored. Thus, the authors in this research proposed a hybrid multi-criteria decision-making model which includes a Spherical Fuzzy Analytical Hierarchy Process (SF-AHP) model and a Multi-Attributive Ideal-Real Comparative Analysis (MAIRCA) model with supports from seasoned domain experts. The contribution of this research is a proposition of a fuzzy decision model for evaluating and selecting open banking business partners. The model successfully determined a suitable open bank provider in order to assist decision makers decide objectively.     

Miniaturized on‐body antenna for small and wearable brain microwave imaging systems

A miniaturized inset‐fed on‐body meandered bowtie antenna designed for brain microwave imaging systems is presented in this article. The proposed on‐body antenna can contribute to the realization of a wearable and portable brain microwave imaging system. The size of 18 × 18 mm² is achieved at a frequency range of 0.75 to 4 GHz by the simultaneous use of self‐complementary structures and meandered lines. The frequency band is a trade‐off between penetration depth and spatial resolution. The proposed antenna performance was studied at different positions on the human head voxel model in terms of several parameters such as reflection coefficient, near‐field directivity, and fidelity factor. In addition, the antenna bandwidth was surveyed on several volunteers using a wearable measurement setup. It has been found that the averages of measured reflection coefficients in different scenarios are in good agreement with the corresponding simulation results, and the antenna shows stable performance under different practical situations. The proposed antenna takes advantage of a small footprint and body matching, which make it an eligible choice for compact, portable, and wearable head microwave imaging systems.     

Robust audio watermarking algorithm based on DWT using Fibonacci numbers

Multimedia Tools and Applications - This paper presents a blind and robust audio watermarking algorithm developed based on Fibonacci numbers properties and the discrete wavelet transform (DWT)...     

Quantitative analysis of sperm rheotaxis using a microfluidic device

Quite puzzling issue in biology is how sperm cells are selected naturally where human sperm has to maintain a correct swimming behavior during the various stages of reproduction process. In nature, sperm has to compete a long journey from cervix to oocyte to stand a chance for fertilization. Although various guidance mechanisms such as chemical and thermal gradients are proposed previously, these mechanisms may only be relevant as sperm reaches very close to the oocyte. Rheotaxis, a phenomenon where sperm cells swim against the flow direction, is possibly the long-range sperm guidance mechanism for successful fertilization. A little is known quantitatively about how flow shear effects may help guide human sperm cells over long distances. Here, we have developed microfluidic devices to quantitatively investigate sperm rheotaxis at various physiological flow conditions. We observed that at certain flow rates sperm actively orient and swim against the flow. Sperm that exhibit positive rheotaxis show better motility and velocity than the control (no-flow condition), however, rheotaxis does not select sperm based on hyaluronic acid (HA) binding potential and morphology. Morphology and HA binding potential may not be a significant factor in sperm transport in natural sperm selection.     

Morphology enhancement of TiO2/PVP composite nanofibers based on solution viscosity and processing parameters of electrospinning method

In this work, different sol solutions with various titanium tetraisopropoxide (TIP)/glacial acetic acid ratios in 2‐propanol with 5 wt % poly(vinyl pyrrolidone) (PVP) (M_w = 360,000 g/mol) were prepared and electrospun. Composition of the prepared sols and as‐spun TiO₂/PVP nanofibers were determined by Fourier transform infrared and Raman spectroscopy methods. Morphology of the electrospun TiO₂/PVP nanofibers was studied by scanning electron microscopy and transmission electron microscopy (TEM) techniques. Rheometry measurements of the sol solutions showed decrease of viscosity upon the addition of TIP to the polymer solutions with constant polymer and acid concentrations. The sol solution having the lowest viscosity (at shear rate 10 s^?1) but the highest TIP/glacial acetic acid ratio showed beaded nanofibers morphology when electrospun under 10 and 12 kV applied voltage while injection rate, needle tip to collector distance, and needle gauge were kept constant. However, smooth electrospun TiO₂/PVP composite nanofibers with the average nanofibers diameters (148 ± 79 nm) were achieved under the same condition when applied voltage increased to 15 kV. TEM micrographs of the electrospun TiO₂/PVP nanofiber showed that the TiO₂ particles with continuous structure are formed at the middle of the nanofiber and distributed along its axis. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46337.     

Effect of polyethylenimine addition and washing on stability and electrophoretic deposition of Co3O4 nanoparticles

In this work, the parameters of cobalt oxide suspension such as conductivity, zeta potential, particle size, stability, and finally the electrophoretic behavior of particles in the absence and presence of polyethylenimine (PEI) in acetone medium were investigated. Also, the effects of washing on the stability and electrophoretic deposition of Co₃O₄ were studied. Characterization of the obtained layer by optical microscopy revealed that there was no deposition in the suspension without PEI, while a uniform layer was formed in the presence of PEI additive. Scanning electron microscopy (SEM) results confirmed the uniformity of layer obtained in acetone using PEI additive. Moreover, SEM results demonstrated that more porous microstructures were obtained at longer deposition durations. The difference in the porosity of the layers, as indicated by the SEM micrographs, is attributed to increase in the deposition time.     

Characterization of piezoelectric ceramics using the burst/transient method with resonance and antiresonance analysis

In this paper, a comprehensive methodology for characterizing the high power resonance behavior of bulk piezoelectric ceramics using the burst method is described. In the burst method, the sample is electrically driven at its resonance frequency, and then either a short circuit or an open circuit condition is imposed, after which the vibration decays at the resonance or antiresonance frequency, respectively. This decay can be used to measure the quality factor in either of these conditions. The resulting current in the short circuit vibration condition is related to the vibration velocity through the “force factor.” The generated voltage in the open circuit vibration condition corresponds to the displacement by the “voltage factor.” The force factor and the voltage factor are related to material properties and physical dimensions of the sample. Using this method, the high power behavior of the permittivity, compliance, effective piezoelectric charge constant, electromechanical coupling factor, and material losses can be determined directly by measuring the resonance (short circuit) and antiresonance (open circuit) frequencies, their corresponding quality factors, the force factor A, and the voltage factor B. The experimental procedure to apply this method is described and demonstrated on commercially available hard and semi‐hard PZT materials of geometry.     

Effect of various surface preparation techniques on the delamination properties of vacuum infused Carbon fiber reinforced aluminum laminates (CARALL): Experimentation and numerical simulation

Carbon fiber reinforced aluminum laminates (CARALL) are one of the aluminum based Fiber metal laminates (FMLs) which, due to their high strength to weight ratio and good impact resistance are greatly replacing aluminum alloys in aircraft structures. In this research work, interlaminate shear strength of Vacuum assisted resin transfer molding (VARTM) manufactured CARALL has been investigated. Numerical simulation model incorporated with real time material data has been developed to predict the delamination behavior of CARALL laminates. Standard CARALL specimens with different surface morphologies were prepared by electric discharge machining, mechanical, chemical and electrochemical surface treatments. T-peel tests were carried out according to standard ASTM D1876-08 to find out inter laminate shear strength. FMLs made out of mechanically, chemically and electrochemically cleaned metal sheets depicted high interlaminate shear strength. SEM micrographs of failed surfaces verify the high adhesive strength of epoxy. Developed numerical simulation model accurately predicts the delamination behavior of CARALL as observed during experimentation.