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Synthesis, photophysical and computational approaches on nonlinear optical (NLO) properties of naphthalen-1-yl ethynylated-chalcone derivative
No full textA new dual mixed moieties of acetylide (C≡C) and chalcone (-CO-CH=CH) system namely 3-(naphthalen-1-yl)-1-(4- (phenylethynyl)phenyl)-2-propen-1-one (3NPP) was successfully designed and synthesized via Claisen Schmidt condensation reaction. Spectroscopic characterization and thermal analysis were conducted via Infrared Spectroscopy (FTIR), 1H and 13C Nuclear Magnetic Resonance (NMR) and Thermogravimetric (TGA) analysis. Density functional theory (DFT) assessment with basis set of B3LYP/6-31G (d,p) was computed to investigate the energy level of HOMO and LUMO, charge transfer within the molecule by global chemical reactivity descriptors (GCRD), molecular electrostatic potentials (MEP) and hyperpolarizability analyses
A new three-term conjugate gradient method with application to regression analysis
Get PDFConjugate gradient (CG) method is well-known for its ability to solve unconstrained optimization (UO.) problems. This article presenting a new CG method with sufficient descent conditions which improves the former method developed by Rvaie, Mustafa, Ismail and Leong (RMIL). The efficacy of the proposed method has been demonstrated through simulations on the Kijang Emas pricing regression problem. The daily data between January 2021 to May 2021 were obtained from Malaysian Ministry of Health and Bank Negara Malaysia. The dependent variable for this study was the Kijang Emas price, and the independent variables were the coronavirus disease (COVID-19) measures (i.e., new cases, R-naught, death cases, new recovered). Data collected were analyzed on its correlation and coefficient determinant, and the influences of COVID-19 on Kijang Emas price was examined through multiple linear regression model. Findings revealed that the suggested technique outperformed the existing CG algorithms in terms of computing efficiency
Virtual reality technology based simulation training system research of pan business English activities
No full textBusiness English proficiency makes great demand on an authentic and information-based environment, especially for non-native English speakers. Therefore, this study was conducted to develop a simulation training system based on virtual reality technology for Business English learners. Virtual Reality technology, characterized by immersion, interaction, inspiration, pertinence, dominance, and openness, can provide a comprehensive and superior training scene for practicing various Business English activities. Hence, this study explores the construction and operation of a virtual reality simulation training system for Pan Business English activities and the application of virtual reality technology in Pan Business English activities. To conclude, although virtual reality technology exploitation is still in the primary stage, the system can significantly improve the learning interest and effect of Business English practitioners
Discovery of multiple representation created by secondary school students in real-world problem solving
No full textPrevious studies indicate that the use of multiple representations helps students become better problem solvers. In this study, the researcher wants to explore and highlight the representation design and develop by the secondary school students during problem-solving in real-world physics problems. The Think-Aloud Protocol (TAP) was developed to provide more information about how students design and use representation to solve problems. The analysis was qualitative in nature, focusing principally on the characteristics of the representations employed as well as the underlying reasoning for their applications. The function of representations created mostly to make students visualize the problem clearly after reading the texts given in the problems. Findings revealed the eleven formats used by students that are divided into four categories: sketch, text, symbolic and mathematics to solve the real problems within the concept of force and motion. These findings are particularly important for teachers to apply multiple formats of representation in teaching physics and problem-solving
28.81% efficient, low light intensity and high temperature sustainable ultra-thin IBC solar cell
Get PDFThe interdigitated back contact (IBC) structure for crystalline-silicon photovoltaic device has long been recognized as an effective technique to overcome the 25% efficiency barrier by shifting all the electrical conducting elements to the backside of the cell. For this structure, the architecture of material interlayer IBC electrodes is very important to reduce the recombination rate without affecting the work function at the metal-semiconductor interface for optimum dissolution and extraction of carriers from the absorber layer. Higher efficiency requires a balance between absolute crystal material and impurities in the semiconductor, doping concentration and PN Junctions, smart grid wires and intelligent sunlight capturing. In this work, the fabrication of a low light intensity functional and high cell temperature sustainable, IBC solar cell is investigated. Silicon-Heterojunction layer to absorb greater solar spectrum and interdigitated N/P contacts have been implemented, which grants the cell to receive full surface sunlight, results in 29% efficiency. Luminous-an optoelectronic device simulator has been utilized to construct a very thin cell with dimensions of 100×150pm. The effects of sunlight intensity and module temperature on the performance have been investigated and the parameters for the most efficient structure were found with 28.81% efficiency and 87. 68%fillfactor rate, making it ultra-thin, flexible and durable providing a wide range of operational capabilities
Silicon nanostructure based surface acoustic wave gas sensor
No full textSurface acoustic wave (SAW) gas sensors with a nanostructured material-based sensing layer are highly desirable in microelectromechanical systems (MEMS) gas sensors to achieve improved sensitivity, time response, and recovery time. Herein, a novel SAW gas sensor with a nanostructured silicon (Si)-based sensing layer was developed. Finite element analysis was employed to determine the dimensions of the sensing material. Moreover, a SAW sensor with a four-pair input/output aluminium interdigital transducer (IDT) was fabricated and tested with carbon dioxide gas (CO2), with a concentration in the range of 500-2000 ppm. The results reveal that an Si nanostructure produces better sensitivity, and faster response and recovery time, compared to a layered Si-based SAW sensor. At 2000 ppm, a frequency shift of 4.62 kHz was recorded, while the time response and recovery time of 31 s and 40.5 s was reported, respectively. The proposed Si nanostructure as the sensing layer for the SAW gas sensor demonstrated significant performance with higher sensitivity than previously reported devices, and has the potential to act as a next generation MEMS SAW gas sensor
Indoor location based tracking using Euclidean distance estimation (LTS-ED)
No full textTo provide location-based services like indoor navigation systems or indoor crowd monitoring systems in an indoor environment, indoor location tracking systems are required. The implementation of an indoor location tracking system employing Wi-Fi signal strength will be the main topic of this study. However, there are several methods for tracking an indoor location, including fingerprinting, triangulation, and trilateration. The proposed system was created using a fingerprinting technique. The server, which is based on Java, and the client, which is based on Android, make up the system's two primary parts. Regarding Wi-Fi RSSI scanning, the client's application oversees removing weak received signal strength (RSSI), more specifically RSSI lower than −85dBm, while the server provides the location ID with the highest likelihood of matching based on offline training data kept in a database. The software algorithm powered by MySQL will be the only foundation for the indoor location monitoring system. The findings demonstrate that smaller-area location tracking provides more accuracy than larger-area tracking
Data-driven model for human tracking and prediction using Kalman filter with particle swarm optimization
No full textIntelligent monitoring systems have evolved due to technological improvement and innovation in biometric identification technology and protecting lives and property. As a result, intelligent monitoring systems are becoming increasingly prevalent. Consequently, this paper proposes the development of an IoT-based Human Tracking system that incorporates the Kalman Filter (KF) Algorithm. Apart from the deployment of the Kalman Filter, analysis was also done with an optimized Kalman filter with PSO (KF-PSO) using Particle Swarm Optimization. Rather than manually tuning the process noise error, R, and measurement error, Q, which are involved in KF, PSO was also used to adjust the errors to obtain their best values for optimal estimation. As a result, a two-dimensional (2D) Kalman filter is developed. The positions and velocities of the object being tracked (i.e., humans) are estimated in x- and y-directions. The proposed system has been evaluated using ten different human datasets, each consisting of 100 samples. The quality performance of KF and KF-PSO models was also compared using accuracy analysis. In comparison, the KF-PSO model yielded an average Mean-Square error of 17 mm (i.e., 1.7% error), while the conventional KF model gave an average Mean-Square error of 22 mm (i.e., 2.2% error). Hence, the KF-PSO model is a better filter than the conventional KF model because of its higher accuracy
Scoping analysis of leveraging IoT with blockchain for monitoring and ensuring efficacy of vaccine cold chains
No full textThe recent pandemic has brought an unprecedented tangible effect on the adversaries of understanding the importance of Vaccines. Prior to this situation there were scenarios where the drip in Vaccine efficacy has affected the public health sector and even the Government's. Vaccination is the only assertive way of procuring immunization against such deadly pandemics. This study discusses such events which motivated the need of managing and monitoring the vaccine supply chain. The applications of IoT and Blockchain have been depicted and converged in this regard. Blockchain is the apparent solution to manage and monitor the vaccines effectiveness by delivering the same to the public health centers timely. Moreover, the counterfeit vaccines can also be identified. Internet of Things (IoT) has given a significant contribution in terms of fetching the real time readings in many applications. In our study temperature and moisture parameters are collected using Sensors in IoT and then the complete voyage of vaccine cold units will be monitored using Blockchain Transactions till it has been delivered. A framework is proposed on a Ethereum platform and consensus mechanism which will eventually avoid any possible alterations and counterfeiting of the deliverable Vaccine Units ensuring a safe transit which will be accessible and transparent even to the receiving patients, healthcare members along with the Governments body
Techno-economic feasibility of biogas renewable energy plant: A case of Malaysian palm oil mill
No full textBased on a chosen case study of palm oil mill, this article presents an analysis of techno-economic feasibility of a biogas renewable energy plant as an alternative eco-friendly system of POME treatment that meets technical and economic constraint for business expansion. By using the multi-criteria analysis method, the closed tank system is identified as the most practical biogas trapping system. The economic analysis with 10.56% internal rate of return, payback time at 8.3 years, and net present value of RM 12,187,432.00 show that the biogas renewable energy plant is economically viable. The study also estimates the total avoided pollution of 8,496 t CO2/year for annual electricity production of 14,160 MWh