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Self-healing fluidic dielectric elastomer actuator
No full textSoft actuator with a large deflection range and a high degree of reliability is essential for microfluidic applications. This paper presents a self-healing fluidic dielectric elastomer actuator (SFDEA) fabricated using ecoflex 00–30. An SFDEA consist of an elastomeric shell filled with dielectric fluid and sandwiched between two compliant electrodes, which actuates when subject to a high voltage. A maximum deflection of 0.72 mm was reported during design simulation at 10 kV applied voltage, with an average of 0.7 mm deflection at higher voltages. Furthermore, at a low operating frequency of 0.5 Hz, the dynamic response deflection of each repeating actuation cycle has attained a high level of reliability. By measuring the effective deflection at each frequency cycle, the device’s performance has been assessed
Signal detection based on atrial fibrillation detection algorithms using RR interval measurements
No full textAtrial Fibrillation (AF) is the most well-known type of heart disease, which can lead to consequences such as stroke, heart failure, and other health issues. Current methods involve performing large-area ablation without knowing the exact location of key parts. The technology's dependability can be used as a target for catheter ablation of atrial fibrillation. The goal of the study is to provide a method for detecting AF that may be utilised in medical practice as a screening tool. The essential objectives for the discovery strategy's configuration are to develop a MATLAB software program that can analyze the complexity of an ordinary ECG signal and an AF ECG signal. The Discrete Wavelet Transform (DWT) is utilized to preprocess the ECG signal. The R peaks and RR Interval of the ECG signal can currently accomplish this. In this study, detection of AF is based on the RR Interval Measurements which are coefficient of variance (CV) and normalised root mean square successive difference (nRMSSD). The threshold value for both RR Interval Measurements for detecting an AF signal is 0.1. As a result, 56.52% of the MIT-BIH Atrial Fibrillation Database and 31.81% of MIT-BIH Arrhythmia Database are identified as AF signals because these signals reach the threshold
Multi-modal simultaneous interpreting teaching: based on situated learning in virtual reality
No full textThe rapid development of computer and information technology has brought new means of support to teaching of conference interpreting. The foreign language teaching environment created by virtual reality technology provides a visual and immersive experience. However, empirical research on the multi-modal interpreting teaching model based on situated learning is still rare. Aiming at the current situation of interpretation teaching, based on multimodality theory and situated learning theory, this paper puts forward a situated multi-modal simultaneous interpreting teaching model supported by virtual reality technology, and has carried out an experimental simultaneous interpreting teaching among senior translation majors in our university for one semester. It is found that this model can stimulate students’ interest in interpreting learning and improve their interpretation competence for they are involved in authentic interpreting task and environment, thus narrow the gap with interpreting market
Sustainability implications of additive manufacturing
No full textAdditive manufacturing is the industrial production name for 3D printing, which is one of the advanced technologies in the fourth industrial revolution. 3D printing involves the production of a 3D product using a layer by layer technique. Complex structures can be produced through AM which was no possible using conventional method as it has the potential to assemble parts, consequently minimizing the production process. In addition, through the AM process, less waste is generated during manufacturing and lightweight components can be produced which makes it beneficial in terms of materials and costs. Therefore, additive manufacturing is seen to have an impact on sustainability. This paper will review the implications of AM on sustainability, which includes the environmental, economic and social aspects. Clear understanding of sustainability impacts of AM is crucial in order to assist companies and researchers to make the best decisions before switching to AM
Microstructure development and wear behavior of Al-15% Mg2Si-xGd composites before and after hot extrusion
No full textThe brittleness of Mg2Si particles in the Al-15%Mg2Si composites needs modification in order to enhance the structure and improve mechanical properties. The influence of Gd additions on the microstructure of primary Mg2Si phases and wear behaviour of Al–Mg2Si before and after the hot extrusion process was investigated. The results showed that the addition of 1.0 wt.% Gd modified the primary Mg2Si morphology but exceeding this level of Gd induced a loss of modification as the primary phase morphology coarsened again. Microstructural analysis results revealed that with 1.0 wt.% Gd addition to Al-15%Mg2Si composite the average particle size and aspect ratio decreased by about 147% and 38.7%, respectively. The results of wear test also showed that composites treated with Gd have higher wear resistance compared with those of without Gd. The highest wear resistance was observed as 0.09517 mm3/km and 0.04953 mm3/km in the composite containing 1.0 wt% Gd for before and after the hot extrusion process, respectively, which is likely the result of effect of hot extrusion in good dispersion of fine Mg2Si particles in the Al matrix
A case study: monitoring and inspection based on IoT for milling process
Get PDFCyber-Physical Machine Tools (CPMT) is currently recognized as a new generation of machine tools that align with Industry 4.0 needs as a smart, well-connected, advanced accessibility and more adaptive and autonomous solution. It can be achieved through standardized design method and communication protocols. This article presents a case study on monitoring and inspection based on Internet of Things (IoT) for milling process toward CPMT. The proposed solution is capable to work in both G-code and Standard for Product Data Exchange Compliant with Numerical Control (STEP-NC)-based controller. The proposed case study demonstrated the controller’s capabilities. An IoT-based monitoring architecture was implemented for milling process monitoring. This approach is suitable for both standard. The interpreted machining information will be utilized to enable the machining parameter update and enable monitoring and machining integration and finally extendable for control activity. The monitoring and inspection approaches can achieve high accuracy of machining process condition detection and enable measurement of machined parts to fulfil CPMT needs and I4.0. The case study validated that the developed monitoring approach performed well and was highly sensitive to any changes during the machining process, specifically on the tool condition. While in the inspection approach, the reliability of the machined model was 99.97%. Based on the results of both the approaches, it is confirmed that both tasks can be designed and support digital factory and other manufacturing process stages in the future such as preventive maintenance, inspecting, sizing, assembling and others
Performance analysis of conditional integrator in NPID controller as cutting force compensator for machine tools application
No full textIn machine tools application, a control mechanism is needed to compensate the presence of disturbance force. Disturbance force can be in many forms depends on the machine tool used or the application. There are a few adaptations that can be made to a controller to achieve a robust control mechanism. The aim of this research is to evaluate the effect of adapting a conditional integrator in a Nonlinear Proportional-Integral-Derivative (NPID) controller to compensate cutting force disturbance in XY ball screw drive table. The control mechanism is evaluated based on the Fast Fourier Transform (FFT) error generated by when simulating the machine operation. The comparison between the normal NPID and NPID with conditional integrator are made in terms of fundamental peak frequency of FFT error to conclude the effect of conditional integrator for cutting force compensation. The outcomes concluded that the addition of conditional integrator further improves the control mechanism as a disturbance compensator
Recent progress in polymeric non-invasive insulin delivery
Get PDFThe design of carriers for insulin delivery has recently attracted major research attentions in the biomedical field. In general, the release of drug from polymers is driven via a variety of polymers. Several mechanisms such as matrix release, leaching of drug, swelling, and diffusion are usually adopted for the release of drug through polymers. Insulin is one of the most predominant therapeutic drugs for the treatment of both diabetes mellitus; type-I (insulin-dependent) and type II (insulin-independent). Currently, insulin is administered subcutaneously, which makes the patient feel discomfort, pain, hyperinsulinemia, allergic responses, lipodystrophy surrounding the injection area, and occurrence of miscarried glycemic control. Therefore, significant research interest has been focused on designing and developing new insulin delivery technologies to control blood glucose levels and time, which can enhance the patient compliance simultaneously through alternative routes as non-invasive insulin delivery. The aim of this review is to emphasize various non-invasive insulin delivery mechanisms including oral, transdermal, rectal, vaginal, ocular, and nasal. In addition, this review highlights different smart stimuli-responsive insulin delivery systems including glucose, pH, enzymes, near-infrared, ultrasound, magnetic and electric fields, and the application of various polymers as insulin carriers. Finally, the advantages, limitations, and the effect of each non-invasive route on insulin delivery are discussed in detail
Unveiling the structural, electronic, and optical effects of carbon-doping on multi-layer anatase TiO2 (101) and the impact on photocatalysis
Get PDFCarbon-doped (C-doped) TiO2 has demonstrated effective photocatalytic activity in the visible-light region. Here, we make use of density functional theory (DFT) methods to understand the photocatalytic activity of C-doped anatase-TiO2 (1 0 1) surfaces as a function of layer thickness. The formation energy results show that C-doped O sites (CO) are more stable in the bulk than in the subsurface or on the surface, while C-doped Ti sites (CTi) are more stable on the surface than in the bulk or subsurface. CO defects introduce impurity states in the band gap, do not affect the band gap energy, and induce an electron trap close to the conduction band edge and enhances light absorption in the visible and IR spectrum. CTi defects induce structural distortions caused by a C–O covalent bond with no impurity states formed in the band gap although there is a reduction in the band gap energy, which leads to a red-shifted absorption. These results shed insight on how carbon doping influences the electronic and optical properties of anatase that can be implemented in the design of semiconductor materials with high photocatalytic activity
Future precipitation projection in Bangladesh using SimCLIM climate model: A multi-model ensemble approach
No full textAppraisal of the long-term precipitation trends and variability is crucial for sustainable water resources management. This research intended to evaluate Bangladesh's monthly, seasonal, and annual spatiotemporal rainfall variability using 40 global climate models for two representative concentration pathways (RCPs), RCP4.5 and RCP8.5. Statistical downscaling climate model (SimCLIM) was used for downscaling and ensemble projection of rainfall in near (2011–2040), middle (2041–2070), and far (2071–2100) futures. Modified Mann–Kendall test was applied to detect future rainfall trends. The results revealed a significant increasing trend in rainfall in near and middle futures for RCP4.5 and in all three future periods for RCP8.5 at all meteorological stations of Bangladesh during significant rainfall months (May–October). The results also showed a decreasing trend in rainfall in dry months (December–January) at many stations. The highest increase in rainfall was projected in June at a rate of 0.10–1.11 mm·year−1 for RCP4.5 and 3.34–4.98 mm·year−1 for RCP8.5 in different future periods. Monsoon rainfall showed the highest increase, and winter rainfall the lowest increase for all RCPs and future periods. The increase in annual precipitation over Bangladesh was projected 2.76–5.98% in three future periods for RCP4.5 and 6.98–26.44% for RCP8.5. These outcomes indicate a possible increase in floods severity and frequency in Bangladesh in the future