bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of DC arcs in a multi-arc generator and their application in the spheroidization of SiO2
*
Authors: Lin Qifu , Zhao Yanjun , Duan Wenxue , Ni Guohua , Jin Xingyue , Sui Siyuan , Xie Hongbing , Meng Yuedong
Published: June 2020

We investigate characteristics of multi-arc torches with three pairs of electrodes (three cathodes and three anodes) and their performance on the spheroidization of SiO2 powder. The effect of electrode arrangement, including adjacent pattern (AD pattern, adjacent electrodes powered by one power supply) and opposite pattern (OP pattern, opposite electrodes powered by one power supply), on the dynamics of arc plasma is investigated based on synchronous acquisition of electrical and optical signals. The results show that both the voltage and spatial distribution of each arc of multiple arcs are more stable compared with those of a single arc. The fluctuation of an arc in multiple arcs mainly comes from the small-scale arc-to-arc restrikes among multiple arcs. Moreover, these arc-to-arc restrikes occur more frequently among multiple arc columns in OP pattern than in AD pattern. Moreover, the high-temperature area of the central region of arc chamber in OP pattern is larger than that in AP pattern. For the spheroidization of SiO2 in this multi-arc generator, the spheronization degrees of plasma treated silica in OP pattern are at least 20% higher than those in AD pattern.
Role of quantum paths in generation of attosecond pulses
Authors: Sami M R , Shahbaz A
Published: June 2020

We investigate the role of core potential in high ionization potential systems on high harmonic generation (HHG) spectra and obtain attosecond pulses. In our scheme, we use a standard soft core potential to model high ionization potential systems and irradiated these systems with fixed laser parameters. We observe the role of these systems on all the three steps involved in HHG process including ionization, propagation and recombination. In our study, the results illustrate that for high ionization potential systems, the HHG process is more sensitive to the ionization probability compared to the recombination amplitude. We also observe that due to the stronger core potential, small oscillations of the electrons during the propagation do not contribute to the HHG spectrum, which implies the dominance of only long quantum paths in the HHG spectrum. Our results, for attosecond pulse generation, show that long quantum path electrons are responsible for the supercontinuum region near the cutoff, which is suitable for the extraction of a single attosecond pulse in this region.
Enhanced reflection chiroptical effect of planar anisotropic chiral metamaterials placed on the interface of two media*
Authors: Yang Xiu , Wei Tao , Chen Feiliang , Gao Fuhua , Du Jinglei , Hou Yidong
Published: June 2020

The strong chiroptical effect is highly desirable and has a wide range of applications in biosensing, chiral catalysis, polarization tuning, and chiral photo detection. In this work, we find a simple method to enhance the reflection circular dichroism (CDR) by placing the planar anisotropic chiral metamaterials (i.e., Z-shaped PACMs) on the interface of two media (i.e., Z-PCMI) with a large refractive index difference. The maximum reflection CDR from the complex system can reach about 0.840 when the refractive index is set as n
top = 4.0 and n
bottom = 1.49, which is approximately three times larger than that of placing the Z-shaped PACMs directly on the substrate (i.e., Z-PCMS). While the minimum reflection CDR is 0.157 when the refractive index is set as n
bottom = 1.49. So we can get a large available range of reflection CDR from –0.840 to –0.157. Meanwhile, the transmission CDT remains unchanged with the refractive index n
top increment. Our in-depth research indicates that the large reflection CDR is derived from the difference of non-conversion components of the planar anisotropic chiral metamaterials’ reflection matrices. In short, we provide a simple and practical method to enhance the chiroptical effect by changing the refractive index difference between two media without having to design a complex chiral structure.
Nonlinear dynamics of a classical rotating pendulum system with multiple excitations*
Authors: Han Ning , Lu Pei-Pei
Published: June 2020

We report an attempt to reveal the nonlinear dynamic behavior of a classical rotating pendulum system subjected to combined excitations of constant force and periodic excitation. The unperturbed system characterized by strong irrational nonlinearity bears significant similarities to the coupling of a simple pendulum and a smooth and discontinuous (SD) oscillator, especially the phase trajectory with coexistence of Duffing-type and pendulum-type homoclinic orbits. In order to learn the effect of constant force on this pendulum system, all types of phase portraits are displayed by means of the Hamiltonian function with large constant excitation especially the transitions of complex singular closed orbits. Under sufficiently small perturbations of the viscous damping and constant excitation, the Melnikov method is used to analyze the global structure of the phase space and the feature of trajectories. It is shown, both theoretically and numerically, that this system undergoes a homoclinic bifurcation and then bifurcates a unique attracting rotating limit cycle. Finally, the estimation of the chaotic threshold of the rotating pendulum system with multiple excitations is calculated and the predicted periodic and chaotic motions can be shown by applying numerical simulations.
On the transport of edge localized mode filaments in the tokamak scrape-off layer
Authors: Adamek J. , Tskhakaya D. , Devitre A. , Cavalier J. , Horacek J. , Komm M. , Sos M. , Bilkova P. , Böhm P. , Seidl J. , Weinzettl V. , Vondracek P. , Markovic T. , Hron M. , Panek R.
Published: June 2020

Microsecond probe measurements of the electron temperature during the tokamak edge localised mode (ELM) instability show that the peak values significantly exceed those obtained by conventional techniques. The temperatures measured at the plasma facing component (divertor) are around 80% of the initial value (at the pedestal). This challenges the current understanding, where only several percent of the pedestal value are measured at the divertor. Our results imply a negligible energy transfer from the electrons to the ions during the ELM instability, and therefore no associated increase of the ion power loads on the divertor. This observation is supported by the simple analytic free-streaming model, as well as by full kinetic simulations. The energetic ELM ion loads are expected to be one of the main divertor damaging factors; therefore, the obtained results give an optimistic prediction for next generation fusion devices.
Simulation on wideband antenna based on Polydimethylsiloxane (PDMS) for medical imaging application
Authors: Haszerila Wan Hassan Wan , Yan Li Nga , Mohd Azize Aziean , Zakaria Zahriladha , Azwan Shairi Noor , Hakim Abdul Hamid Mohd
Published: June 2020

This paper presents an antenna for the medical imaging application which can detect unusual tissues on any part of the body. A design of wideband antenna with wearable properties is proposed for the medical imaging application. The wideband antenna is designed with introducing notches to the patch and a t-shaped slot at the partial ground. Polydimethylsiloxane (PDMS) is introduced to the antenna for the implementation of the wearable antenna. The proposed antenna operated in a frequency range of 3GHz to 6GHz. The antenna that embedded with PDMS shows a good agreement to the antenna without PDMS. The overall dimension of the antenna is 24mm (W) x 38mm (L) which consider is a miniature antenna. This proposed design gives an alternative solution for the antenna which cannot be wear on the body and protect the antenna. The introduction of PDMS will reduce the signal reflection cause by the high coupling of the human body.
Solar panel receiver characterisation for indoor visible light communication system
Authors: Zaiton AM , Muhammad HR , Jasman F
Published: June 2020

Visible light communication (VLC), where light is used for illumination and communication simultaneously is considered as one of the enabling technology for the fifth-generation (5G) communication standards. Recently energy harvesting capabilities is proposed to be integrated into VLC system by employing a solar panel as the photodetector instead of using the commonly used photodiode. In this paper, an experiment is conducted to analyse the performance of two types of photodetector at the receiver namely a photodiode and a solar panel. First, the transmitter and receiver circuits are built for both unmodulated scheme and modulated scheme using On-off keying (OOK). The performance of unmodulated scheme is included for comparison purposes. It is shown that the transmission distance obtained by using photodiode is better than the solar panel.
Challenges and opportunities for Integrated Broadcast Broadband (IBB) implementation in Indonesia
Authors: Ariyanti Sri , Yuniarti Diah
Published: June 2020

TV consumption patterns around the world have changed dramatically since the appearance of over the top service. Integrated Broadcast Broadband (IBB) system provide value services that attract customers to enjoy traditional TV services compared to OTT services. ITU-R define IBB system as a combination of broadcast and broadband technology, which provides high quality, flexible, interactive, and personable services. This study aims to determine the challenge and opportunities of implementing IBB in Indonesia. The research method is carried out with a qualitative data approach using PEST analysis. The results showed that IBB has potential opportunities to be applied in Indonesia since the digital terrestrial television coverage has reached more than half of the population. Moreover, the increasing number of digital satellite television subscribers, as well as IPTV subscribers, provide a potential market for IBB services. However, the lack of supporting broadband infrastructure and digital terrestrial television regulations uncertainty will be a challenge for the success of IBB implementation in Indonesia.
Optimized state feedback control of quarter car active suspension system based on LMI algorithm
Authors: Babawuro A Y , Tahir N M , Muhammed M , Sambo A U
Published: June 2020

Suspension systems are applied in vehicles so as to improve the passengers ride comfort, vehicle stability and better road handling when the vehicle moves on roads with bumps and terrains. In this paper, Linear Matrix Inequality (LMI) and linear quadratic regulator (LQR) controllers were proposed and this was also compared with passive suspension system. Using nonlinear quarter car active suspension system model with hydraulic actuator to reduce the effect of bumpy road surfaces on vehicle and hence improve passenger ride comfort. Vehicle body suspension travel and wheel deflection were measured to determine the performance of the active suspension system. Mean absolute error (MAE) and integral square error (ISE) were used as the performance indexes, thus a MAE and ISE of passive 75.01%, LQR 82.65% and LMI 89.11% and passive 4.11x10−6, LQR 3.24x10−6 and LMI 2.19x10−6 respectively were recorded. Based on the simulation results and analysis, the LMI based control performs better in minimizing vibration effects and also guarantee better ride quality and vehicle stability when compared to the conventional LQR and the passive suspension system.
Simulation and analysis of flexible TEG using polymer based and pyroelectric material for microdevice energy harvesting
Authors: Bakhari N A , Hamid N A , Syafeeza A R , Wong Y C , Ibrahim M
Published: June 2020

Recently, an interest of thermoelectric generator (TEG) to manipulate and change heat waste into electrical energy has increased. The heat from electrical appliances, sun, human body, and natural environments can convert into electrical energy using TEG. However, typical conventional TEGs in the market have a hard and solid construction structure, hence difficult to bend according to curved surfaces of the heat sources. To overcome this problem, polymer-based material is proposing as the new packaging and substrate structure for the TEG. Besides, the thermoelectric conductor layer also changed using different types of pyroelectric for better heat absorption performance with low cost in mass-scale fabrication. Therefore, the simulation of eight pairs segmented conductive layer insulated with thin-film polymer due to standard modelling equation is present. The comparison of simulation with reference TEG to get the optimum output of temperature difference were also explaining. At the end of the simulation, polyimide as a packaging substrate with a conductive layer of Graphene (P-type legs) and Bismuth Telluride (N-type legs) has chosen for the best performance material for the flexible thermoelectric generator. The highest temperature difference produced by this design is 542˚C for 0.945V input voltage and 120˚C input temperature at the hot side.
Design and analysis of a dual function of switchable resonator for RF switch
Authors: Shairi N. A. , Zobilah A. M. , Zakaria Z. , Othman A. , Weng S. Y.
Published: June 2020

This paper presents the design and analysis of a dual function of a switchable resonator for Radio Frequency (RF) switch. The most common configuration of RF switch is Single Pole Double Throw (SPDT) switch that widely used in the wireless communication system. In order to achieve the dual function between isolation improvement and band-stop filter in SPDT switch, two switchable resonators were used that resonated at 2.3 and 5.2 GHz bands. PIN diodes were used as switching elements in the SPDT switch. The main advantages of the dual function of the switchable resonator are minimum usage of switching elements for isolation and integrated band-stop filter in a single device of SPDT switch. As a result, the design showed almost 40 dB of isolation at 2.3 GHz and 39 dB of the notch response of the band-stop filter at 5.2 GHz.
Low-sampling rate data-based failure diagnosis by using self-powered system
Authors: Okada S , Hashimoto S , Basari A A
Published: June 2020

In recent years, in order to solve critical problems such as global warming and climate change that have been occurring in the world, research on the application of power generation methods which are harmless to the environment has been underway. In this paper, a fault diagnosis method using the self-powered sensing system based on vibration power generation is proposed. Frequency analysis is known as a general failure diagnosis method. However, due to the limitation of the generated power, the sampling period of data acquisition is as large as a few-ten millisecond. For this reason, it is difficult to use frequency analysis for fault diagnosis using vibration power generation. Therefore, a fault diagnosis system corresponding to an increase in the sampling period is constructed by introducing machine learning. An acceleration sensor used for data acquisition is driven by the vibration power generator attached to factory equipment. The diagnosis is performed by wireless-transmitted acceleration data. By introducing a machine learning strategy into the diagnosis, accurate diagnosis can be performed even for data with low-sampling rate. The effectiveness of the proposed diagnosis method is experimentally evaluated by using the factory equipment.
Design of Sunda Straits automatic water level station network
Authors: Sugiarto  , Wijaya S K , Rosid M S
Published: June 2020

The Sunda Strait is a region that has the potential for tsunamis due to tectonic and volcanic activities. Anak Krakatau landslide is one of the causes of Tsunamis that require accurate early detection by combining data from seismometers and other sensors. One of the instruments that can be implemented in the verification of early detection of Sunda Strait Tsunami waves is a network of automatic water levels that can measure changes in water level every one minute. The system is designed using ultrasonic water level sensors and rainfall sensors. The sensors are connected to a data logger for processing data with a solar power supply panel. The automatic water level network is installed in 3 locations around Anak Krakatau. Measurement data from sensors is sent to BMKG servers for further processing using 2G communication modules. The results of the system design show that the network of automatic water level works properly, where the pattern of water level patterns every minute from each station can be seen.
Real time mobile based license plate recognition system with neural networks
Authors: Liew Connie , Kim On Chin , Alfred Rayner , Tse Guan Tan , Anthony Patricia
Published: June 2020

In this paper, the implementation of localizing and recognizing license plate in real time environment with a neural network using a mobile device is described. The neural networks used in this research are Convolutional Neural Network (CNN) and Backpropagation Feed Forward Neural Network (BPFFNN). Image processing algorithm for pre-processing, localization and segmentation is chosen based on its ability to cope with limited computational resource in mobile device. The proposed license plate localization steps include combination of Sobel edge detection method and morphological based method. Detected license plate image is segmented using connected component analysis (CCA) and bounding box method. Each cropped character is fed into CNN or BPFFNN model for character recognition process. The neural network model was pretrained using desktop computer and then later exported and implemented in Android mobile device. The experiment was conducted in a moving vehicle on selected driving routes. The results obtained showed that CNN performed better compared to BPFFNN in a real time environment.
Comparison of simple feedforward neural network, recurrent neural network and ensemble neural networks in phishing detection
Authors: Kim Soon Gan , Kim On Chin , Mohd Rusli Nordaliela , Soo Fun Tan , Alfred Rayner , Tse Guan Tan
Published: June 2020

The internet has been one of the greatest advancements in technologies. It has brought many advantages to today’s society in many domains such as e-commerce, entertainment and supply chain, amongst others. However, it is also a double-edged sword which has brought many threats to the computer systems and devices known as cyber-attack, and one of these threats would be phishing attack. A phishing attack is where the scammer tries to impose or clone the legitimate email or website in order to deceive the victim to key in their personal information such as username and password. Phishing attack has been one of the most common attacks that happens every day on the Internet especially through email. Many methods have been devised to encounter phishing attack, and one of approaches is through training and monitoring team. These manual approaches, however, are user’s experience-dependent and cost-inefficient. Therefore, many have adopted AI approach instead to detect phishing attack. This paper is one of the many efforts to detect the phishing attack through email by adopting AI method. The objective of this paper is to investigate the performance of feedforward neural network, recurrent neural network and ensemble neural network in phishing email detection. The result of this comparison is empirically evaluated.
The initial socio-technical solution for phishing attack
Authors: Fajar Abdullah , Yazid Setiadi
Published: June 2020

A phishing attack remains popular among security attacks, which has specific characteristics. The attacks have an impact on the economy and involve user behaviour that makes the attack successful. Many solution framework and program has developed but fails for eliminating the attack except minimizing the impact only. Mitigating and cope processes for reducing phishing attacks involve user education and training to raise higher user awareness. The mitigating process itself has two main steps that are prevention and detection. Many algorithms employ machine learning to overthrow the attack intelligently. The remaining problem of this process is detection time is slower than using blacklist filtering. The paper review social and technical aspects to conclude and identify the potential solution that will be proposed for the next stage of the research. The potential solution will include future data analytics such as an immersive and augmented analytic regardless of computing issues. An immersive and augmented analytics should have the ability to learn from the past data of user and attack behaviour to direct the system and user in combating the attacks. The learning result should give preventive suggestions and evaluate user awareness level.
Garbage monitoring systems based on Internet-of-Things application
Authors: Ali N. A. , Syafeeza A.R. , Ja’afar A. S. , Abdul Hamid Norihan , Ridzuan M.
Published: June 2020

Garbage management is one of the primary problem faced by cleaners in terms of the duration of the cleaning process. The design of a smart green environment of garbage monitoring systems is developed based on an IoT (Internet of Things) application is believed to overcome this waste issue. The main contribution of this project is demonstrated by a system based on IoT that allows the waste management to monitor based on the garbage depth inside the dustbin and also the notification of its full condition by using a mobile phone and the Blynk apps. The proposed system consisted of the ultrasonic sensor, which measures the garbage level inside the dustbin. The system shows the status of the garbage through LCD, and a WiFi module (ESP8266) used to send the information to the smartphone. Thus, it is expected that this system can build a greener environment by monitoring and controlling the collection of garbage smartly through an IoT application.
Impact of strained channel on electrical properties of Junctionless Double Gate MOSFET
Authors: Kaharudin K E , Salehuddin F. , Zain A S M , Roslan Ameer F , Ahmad I
Published: June 2020

Application of strained channel in Metal-oxide-semiconductor Field Effect Transistors (MOSFET) technology influences the electrical properties due to the significant changes in the energy band structure of silicon lattices. Thus, in this paper, a comprehensive analysis is conducted to investigate the impact of strained channel towards several electrical properties of junctionless double-gate MOSFET. The comparative analysis is carried out by simulating two different sets of device structure which are JLDGM device (without strain) and junctionless double-gate strained MOSFET (JLDGSM) device. The results show that the strained channel has improved the on-state current (ION), on-off ratio, transconductance (gm) and transconductance generation factor (TGF) by approximately 58 %, 98%, 98%, and 44% respectively. The significant improvement is mainly attributed to the presence of biaxial strain boosting the electron mobility in the channel. The intrinsic gate delay (τint) has significantly reduced by approximately 52% as the strained channel is applied. Since the variation of intrinsic gate capacitances (Cint) is very minimal (4%) as the strained channel is applied, the gate delay is dominantly governed by the drain current. However, the application of strain channel has increased the dynamic power dissipation (Pdyn) for approximately 19% mainly due to slightly increased intrinsic gate capacitances.
Region-based segmentation and classification of Mandibular First Molar Tooth based on Demirjian’s method
Authors: Mohammad N , Yusof M Y P M , Ahmad R , Muad A M
Published: June 2020

Dental age estimation is applied in various clinical and scientific disciplines such as pediatric dentistry, orthodontics, archaeology, palaeontology and forensic dentistry. Dental age assessment, particularly in forensic dentistry application for the purpose of human identification, has led to the fastest and cheapest procedure in the estimation process of the undocumented and unrecognized individuals. Traditionally, dental age assessment is done by applying the scoring system based on tooth development from the x-ray image. However, this method can be intricate and time consuming for massive incidents that involve a large number of victims such as a natural disaster. Thus, a number of experts are required during the identification process. Therefore, in this research, the application of digital image processing techniques is used to perform the segmentation and classification of the first molar tooth in every stage of its development. A region-based segmentation method known as Watershed Transform associated with several image enhancement algorithms is implemented. A marker image is automatically computed to control the operation of a watershed transform. Features are extracted based on the area of a segmented tooth, size of crown, the distance of left crown to root and distance of right crown to root. As a result, 94% and 92.8% of segmentation and classification accuracy are obtained.
Comparison of global and local features for author’s identification by using geometrical and zoning methods
Authors: Jalil I E A , Shamsuddin S M , Muda A K , Azmi M S , Hasan S , Ahmad S
Published: June 2020

Identification analysis for author’s handwriting image in forensic investigation is still an important research area in this current big data era. Images feature extraction can lead to an issue of high dimensionality of data. The process of feature extraction is the most crucial process in author’s identification. It is important to choose the best method to represent the image. This study compared two feature extraction methods, namely Higher-Order United Moment Invariant (HUMI) and the Edge-based Directional (ED) method that construct the Global and Local Features respectively. The additional process of discretization was implemented before the training and testing phase to represent the generalized features for the classifier models. This process induced a better performance accuracy for both methods where the discretized Local Features achieved 99.95% accuracy rate that slightly outperforms the discretized Global Features with only 99.91%.
Classification and detection of chili and its flower using deep learning approach
Authors: Saad W H M , Karim S A A , Razak M S J A , Radzi S A , Yussof Z M
Published: June 2020

This study presents an application of using Deep Neural Network (DNN) based detector to detect chili and its flower in the chili plant image. Detecting chili on its plant is important for the development of a robotic vision to automatically picking the chili. Only one type of local chili variety is used in this study from the species of Capsicum frustecens. Five hundred of chili plant images were captured from multiple angles and each of images was marked and labelled for any present of chili and its flower. These images were divided into 70-30 per cent proportion for training with validation and testing purposes accordingly. This project uses Faster Regions with Convolutional Neural Networks (R-CNN) as a deep learning model for training that contains around 177 numbers of layers including input and output layers. The classifier network was trained to optimize all parameters involved in chili and its flower classification and detection. The classification and detection accuracy are measured on the tested images. The result shows very good accuracy in validation and testing for classification and detection especially with the image of chili plan is upright position.
Molecular dynamics simulations of ionic hydration of Na+ inside the nanochannel
Authors: Li J P , Li Y S , Wang Z , Wang H C
Published: June 2020

Molecular dynamics simulations were carried out to investigate the hydration of Na+ ion in the nanochannels. The height of the channels varies from 0.65 nm to 3.0 nm, and the surface charge density varies from 0 to -0.2991 C/m2. The simulation results showed that the channel height and surface charge had special effect on the hydration of Na+ ion, and the peak height of radial distribution functions and coordination number increased as the channel height and surface charge density decreased. In the region of electrical double layer, hydration radius increased with the decreased of the channel height and the surface charge density, but the hydration radius of the Na+ ion of the bulk region was kept at a constant.
Effect of heat treatment on the microstructure and mechanical properties of electroless nickel-phosphorus coatings
Authors: Cheng Kun , Wu Zhaofeng
Published: June 2020

Electroless deposition have been considered as one of the most important nickelbased coating synthesization methods because of their coatings uniformity, high wear resistance, excellent corrosion and electrical properties. In this paper, nickel-phosphorus coatings were synthesized by electroless method on medium carbon steel substrates. The effect of heat treatment on the microstructure and mechanical properties of nickel-phosphorus coatings were investigated in detail. Structural analyses suggest that the coatings remain amorphous structure if the annealing temperature is below 400 °C. The crystalline Ni and Ni3P were formed in the coatings when the annealing temperature reach 400 °C and the grains grown significantly with increasing the heat treatment temperature from 500 °C to 800 °C. The mechanical properties of the nickel-phosphorus coatings display a significant change with the different heat treatment temperature. It was found that the highest microhardness value and the best wear resistance property has been obtained under heat treatment temperature of 400 °C. The possible mechanism of the relationship between microstructure and mechanical properties was also explored.
Research on Microfluidic Chip Design and Droplet Related Technology
Authors: Zhen Su , XiaoMing Han , QuanJun Liu
Published: June 2020

Microfluidic Chips, also known as chip labs, integrate basic operating units in the fields of chemistry and biology on a chip. The droplet is a technique for controlling a small volume of liquid on a microfluidic chip. One of the two incompatible liquids is used as one continuous phase and the other as a dispersed phase, and the dispersed phase is dispersed in a continuous phase in a micro volume unit. Droplet fusion is the basic tool for controlling droplets in microfluidic devices and their use as microreactors, allowing precise mixing of reagents and fusion of samples at well-defined points in space and time.This topic is based on microfluidic technology, designed and processed PDMS chip, research on droplet generation and droplet fusion technology in microfluidic chip. Using a constant pressure pump designed by the laboratory to drive the sample injection, study the effects of continuous phase, discrete phase convergence angle, flow path width, liquid flow rate, etc. on the droplet formation of the cross-shaped structure. Based on the droplet generation technology, The subject then studied the droplet fusion technology, completed the droplet fusion chip design and processing, and achieved 1:1 1:2 fusion of two sample droplets.
Microdroplet event recognition and volume detection system based on flexible printed circuit electrode
Authors: Han Xiaoming , Su Zhen , Xu Ying , Liu Quanjun
Published: June 2020

Changes of microdroplet volume and the occurrence of different droplet events will exert a significant influence on droplet-based microfluidics. Droplet volume is closely related to reagent consumption and hydrodynamic resistance while droplet events reflect actual microchannel conditions. Based on current research, this work was dedicated to fabricate a reliable microdroplet sensing system with event recognition and volume detection function. Signal acquisition was on the basis of capacitance coupled detection and the coplanar fork sensing electrode was fabricated by flexible printed circuit(FPC) which was tens of times cheaper than photolithography. Wave peaks will appear while ink droplets traverse over the fork electrode from above. Shape features of waveform were used to recognize some simple droplet events and the period was employed to calculate droplet volume. Through experimental verification, droplet generation and droplet merging events could be recognized and distinguished by the system. In addition, the detection error between the theoretical volume calculated from formula and the actual volume derived from image analysis was less than 0.5 nL. The sensing system possesses the potential to achieve high throughput detection and surely can be employed to recognize more complicated droplet events in the future.
Flexible and ultrasensitive surface-enhanced Raman scattering substrates for the pesticide detection
Authors: Wang Runhua , Zhu Jia , Lin Guanzhou , Wu Wengang
Published: June 2020

In this paper, a simplified method for preparing surface-enhanced Raman scattering (SERS) substrates with spin-coating is reported. The green chemical synthesis of Ag nanoparticles (NPs) is environmentally friendly without complex instruments. The Ag NPs are coated on a polydimethylsiloxane (PDMS) film by spin coating for detecting pesticides. By this method, we can get the substrate with high sensitivity. The results showed that the substrate has a strong SERS signal even the concentration of thiram (pesticide) is down to 10−9 M. Compared with the allowed residue dose in food security (10−5 M), the detection limit of thiram is lower. On the other hand, PDMS has the advantage of flexibility and transparency, it can meet the demands of the detection of analytes on irregular objects.
Effects of Label-free Fluorescence Aptasensors with Different Aptamer Length on Quenching of Carbon Dots
Authors: Ren Linjiao , Xu Peng , Zhang Pei , Qin Zirui , Hang Xinxin , Li Chenlong , Meng Xiaolong , Xu Xiaoping , Jiang Liying
Published: June 2020

Label-free fluorescence aptasensors have the advantages of better detection sensitivity, simple manufacturing process and no pollution. In this experiment, the effect of aptamer base number on the performance fluorescence aptasensors has been studied. Thrombin of 15 base number, ATP of 27 base number and DA of 58 base number were selected, and then constructed three kinds of fluorescent probes about Au/Aptamer/CQDs nanostructures with gold nanoparticles and carbon dots. By studying the quenching degree of carbon dots with each probe, the quenching degree of carbon dots fluorescence by ATP probe was the highest, thrombin probe was the worst, and the DA probe was between ATP probe and DA probe. This indicates that with the increase of the aptamer base number in the probe, the more carbon dots are adsorbed on the aptamer and the more fluorescence quenching occurs, but the aptamer will be winding when it has too many bases, leading to the quenching unstable of carbon dots fluorescence. This study provides a useful reference for the construction and detection of fluorescent aptasensors, and has a great potential in the field of small molecule detection.
Long-term Stability Enabling Technology of Silicon-Based Piezoresistive MEMS Pressure Sensor
Authors: Liu S , Du X H , Zhu M J , Liu D
Published: June 2020

Silicon-based piezoresistive microelectromechanical systems (MEMS) pressure sensor is one of the best studied and commercialized devices among all MEMS devices due to simple structure, easy reading circuit, strong batch fabrication capability and low price. The biggest technical bottleneck of this sensor for high-end applications such as aerospace is long-term stability after packaging. Therefore, long-term stability improvement technologies, as the common key technologies, have been widely concerned by academia and industry. In this paper, three common enabling technologies including pulsating fatigue, thermal-cold cycling and vibration aging are adopted to evaluate the effect of long-term stability of silicon-based piezoresistive MEMS pressure sensors by using control variable method and orthogonal test (OT) method. The comparative test results indicate that all these three technologies can improve the long-term stability of the pressure sensor. In addition, an optimized combination of environmental stress parameters is found to improve the stability more than 90% higher than before the test. The long-term stability of the sensors through the optimal parameter combination aging method is better than the original factory method. The research results can be used for reference to improve the long-term stability of various silicon-based pressure sensors.
Reduced Graphene Oxide Wrapped Ultra-thin Silicon Nanowires for Lithium Ion Battery Anodes
Authors: Sun Fang , Hu Zhengguang , Wu Leyuan , Chen Jun , Luo Jie , Wu Xiaoling , Cheng Guoan , Zheng Ruiting
Published: June 2020

Nowadays, silicon is becoming a promising kind of material for lithium ion batteries (LIBs) because of its high theoretical capacities. In this paper, we developed a new Bi-metal assisted chemical etching (BACE) method to fabricate ultrathin silicon nanowires (UTSiNWs) with an average diameter of 30 nm, and fabricate reduced graphene oxide wrapped UTSiNWs (UTSiNWs@rGO). The UTSiNWs and UTSiNWs@rGO anode have a discharge capacity of 1011.6 mAh/g and 2013.1 mAh/g under the current density of 300 mA/g. Retention rate of the UTSiNWs and UTSiNWs@rGO anode are 93.3% and 76.6% respectively. Although the discharge capacity decreased due to the side reactions caused by the increased interface, the discharge capacity of UTSiNWs@rGO anode is still higher that of UTSiNWs anode because of the electron conductivity of the anode is improved.
Hollow sandwich-structured N-doped carbon-silica-carbon nanocomposite anode materials for Li ion batteries
Authors: Tang Xinde , Zhao Chunli , Li Zhanfeng , Zhang Yipin , Gu Shaonan
Published: June 2020

Silica has attracted much attention as a promising anode material for lithium ion batteries (LIBs), however, the low conductivity and unstable solid electrolyte interface (SEI) film limit its applications. In this paper, hollow sandwich-structured N-doped carbon-silica-carbon (CSC) nanoparticles was designed and prepared as anode materials for LIBs. The combination of polymer template approach and dopamine self-oxidation polymerization results in the conformal coatings on the surface of silica, which enhances the conductivity and stability of the composite materials. The hollow sandwich-structured material displays a high reversible capacity of 480 mA h g-1 at current density of 1.0 A g-1 and excellent rate performance, which can be attributed to the synergetic effect of the unique structure of hollow silica and N-doped carbon conformal coatings. The hollow sandwich-structured N-doped carbon-silica-carbon composite materials can be promising anode materials for LIBs.
A novel Cu2O/Cu grid for photoelectrochemical water spliting
Authors: Wang Xing , Chen Jun , Wu Xiaoling , Cheng Guoan , Zheng Ruiting
Published: June 2020

In this study, we reported a novel metal-semiconductor junction grid, which is made of Cu and Cu2O. The Cu2O film is deposited on the surface of a Cu grids by a simple electrochemical deposition method. Cu grids with 200 mesh has larger specific surface area than that of Cu sheet and will enhance the water splitting performance of photo-electrodes. Different Cu-Cu2O grid samples were prepared by changing the electrodeposition time and current. The best deposition parameters for Cu2O films on Cu grids were 3 hours of deposition time and 0.4 mA/cm2 of deposition current density. Under the best condition, the highest photocurrent density was −3.83 mA/cm2 which was higher than −2.36mA/cm2 of Cu2O films on Cu sheet.
Chaotic continuous growth model for dragons based on an ecological assessment system
Authors: Zhang Z C , Zhang B W , Chen J Q , Pan X T , Cyu W , Zhou W , Zhang D H
Published: June 2020

As a magical immortal creature in the game world or internet world, the dragon has a huge volume, excellent flight capabilities, and fire-spraying skills. Exploring the growth of dragons is innovate and legendary significance to the deep exploration of the universe by mankind. The characteristics of dragon growth and its influence caused by the environment were studied, the factors causing energy change in dragons were fully analysed, several differential-equation models were established to solve the changes of energy in dragons, and the influence of their environment on dragons. By studying the question of whether three dragons can coexist, we find that the habitat and range of one of them will change due to the different relationships between the other two dragons, so we established a two-layer system to solve the reciprocal competitive relationship between two dragons and established a chaotic continuous model of three dragons.These conclusions can also be used to evaluate the use of some easily dissipated device materials, calculate the life span and optimal service life of some materials, solve problems governed by system models with interactive effects therein.
Investigating the Moderating Effect of Demographic Variables on ICT Usage and Learning Process Quality of Higher Education in Medan, Indonesia
Authors: Lubis Andre Hasudungan , Idrus Syed Zulkarnain Syed , Sarji Asiah , Lubis Zulkarnain , Sutrisno
Published: June 2020

ICT and education seem inseparable. To improving the quality of learning process, ICT become the medium to assist the lecturer to transfer the knowledge to the students with more interactive. The study examined the moderator effects of demographic variables to influencing the usage of ICT towards learning process. A total of 260 respondents were selected from 733 of lecturers in three largest private universities in Medan, Indonesia. Data were collected through a survey among the participants manually. The research employs the Pearson Correlation to determine the relationship between variables and to test the hypothesis, the study uses the Simple Linear Regression and Hierarchical Regression. Result reveals that gender and educational level have no significant moderation. In contrast, teaching experiences, age, and department origin yet significant and positively as the moderator. Moreover, ICT usage is significant to impacting learning process.
A New Perspective of Web-Based Systems Quality Engineering Measure by Using Software Engineering Theory (ISO 25010): An Initial Study
Authors: Fadhel Ibrahim Eskandar Ibrahim , Idrus Syed Zulkarnain Bin Syed , Abdullah Mohd Syukri Yeoh , Ibrahim Amani Ali Elmetwaly Ali , Omar Mazni , Khred Ahmed
Published: June 2020

An extensive number of engineered frameworks and web assessment accessible are not good enough in the appraisal of systems’ quality. Thus, the comprehension of the systems’ quality in Mukalla, is basically critical. The research literature review aims at developing a successful novel theoretical approach for measuring system. The research contribution can be seen theoretically, in the methodology and practical perspectives. Theoretically, it presents a refined expansion of up-to-date DeLone and McLean’s information success framework (2003), TAM and ISO 25010 posits that some factors are directly related to satisfaction. The need to answer why users dislike system after the initial experience must be known. Methodologically, the contribution of the research study will be performed using census and other data collection processes from student were instruments will be validated by 8 experts. Lastly, some factors like loyalty, security and benefits would be adapted and employed on non-commercial settings
An Integration between Information Systems Engineering and Software Engineering Theories towards Engineering a Novel Instrument and Framework of Web-Based Systems Success: Hypothesis Testing
Authors: Fadhel Ibrahim Eskandar Ibrahim , Idrus Syed Zulkarnain Bin Syed , Abdullah Mohd Syukri Yeoh , Ibrahim Amani Ali Elmetwaly Ali , Omar Mazni
Published: June 2020

Systems and its success evaluation are an important prospect whereby, several studies can be traced, outlining its importance and vitality. However, there is a need to identify responsive specific factors to help better understand the systems determinants and its success evaluation. In the academia, systems are used to facilitate students, human resource, e-commerce activities any much more. Hence, examining the systems and evaluating as to what length it is successful is essential. This study aims to provide the results of the hypothesis testing. There have been 7 accepted hypothesis and 3 rejected hypotheses. Hypothesis results showed that ISO 25010 works better than TAM and DM Models in systems success measurement.
An Integration between Information Systems Engineering and Software Engineering Theories towards Engineering a Novel Instrument and Framework of Web-Based Systems Success: Results of the Pilot Test
Authors: Fadhel Ibrahim Eskandar Ibrahim , Idrus Syed Zulkarnain Bin Syed , Abdullah Mohd Syukri Yeoh , Ibrahim Amani Ali Elmetwaly Ali , Omar Mazni , Ghazi Alaan
Published: June 2020

Due to globalization and speedy of ICT and systems development, more emphasis needs to be on quality of systems and it requires an accurate, fast, effective system so that the success measure of system is essential. Currently systems rate of fall is still a high one of the reasons behind that is the weakness of the available instruments that being used for systems success measurement. This study aims to come out with a successful instrument for successfully system quality measuring. In this article, the results of the pilot test have been illustrated.
Evaluation of MRI images’ pixels intensity in three different MRI sequences
Authors: Arsat Zainal Abidin , Halim Kadarman A. , Shokri Amran Ahmed , Aziz Mohd Ezane , Shuib Solehuddin
Published: June 2020

Numerous types of Magnetic Resonance Imaging (MRI) sequence have been utilized for in vivo tibiofemoral contact area study has led inconsistency and disproportionate results. Thus, this study aim is to assess intensity differences of MRI images in three different MRI sequences. Ten healthy subjects with average age of 25.5 ± 4.76 consisted three males and seven females have no history of knee injuries participated in this study. Subjects were scanned through an Achieva 3.0T TX coupled with a SENSE spine coil 15. The selected MRI sequences were Turbo Spin Echo (TSE), Fast Field Echo (FFE) and Steady State Free Precision (SSFP). The results showed that the SSFP sequence consistently uncovered extra contact areas than the FFE and TSE sequences. Overall intensity value indicated that the TSE sequence intersected the highest intensity differences at important knee tissue components: trabecular-cortical and cartilage-synovial. The study demonstrated that the TSE sequence yields an accurate contact length detection which promoted a consistent tibiofemoral contact area for quantification. Also, this study suggested that the TSE sequence is a proper MRI sequence selection for in vivo tibofemoral contact area study.
Antecedent, Consequences, and Policies View of Cyberloafing among the Employees
Authors: Dmour Mohmmad M. , Bakar Hanif S. , Hamzah Mohammad R.
Published: June 2020

As the Internet has brought a lot of benefits to the work the Internet also creates new problems that were not found before as the cyberloafing. the cyberloafing defined as an activity involving the use of smart mobile and computers devices at the workplace for personal purpose activity by employees. In this paper, the researcher going to show some the demographic areas and the factors that effect on the employees’ attraction to cyberloafing from the previous studies have been shown consciences of cyberloafing in both of employees and organization. Finally, this paper will present some of the strategies to control and reduce the cyberloafing in the organizations.