bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Development of an Autonomous Quadruped Robot
Authors: Sandeep B , Tamil Selvan P
Published: January 2021

This research paper contains the work done on the ‘Design and development of an Autonomous quadruped robot’ – a system engineered to complete tasks like carrying weaponry and materials for military applications. The primary aim of the project was to design a quadruped that works successfully in harsh conditions and irregular terrain were human intervention is impossible or hard. Initially, individual components of the design were designed and modifications were made according to the requirements. The development was carried out in five major steps including frame assignment, DH parameter analysis, Kinematic and dynamic analysis, Multibody simulation, Stability analysis and execution of gaits. The average time taken for the device to complete on cycle was found to be 10 seconds in crawl gait and around 8 seconds in trot gait. Further tests on the final device also directed a consistent results in its functionality and time taken for the quadruped to complete one gait cycle.

As such, the performance of the quadruped is found to be successful and also open to further modification for better performance and varied usage requirements since the research on autonomous quadruped is at its early stages of development.
Optimization of quadcopter frame using generative design and comparison with DJI F450 drone frame
Authors: Bright Jerrin , Suryaprakash R , Akash S , Giridharan A
Published: January 2021

This research accentuates to explore designing the drone frame using Generative design tools. A quadcopter is designed using Autodesk generative design embedded in Fusion 360. The simulation results such as static stress-strain, modal frequency and displacement results of additive manufactured quadcopter are compared with a DJI flame wheel F450 drone frame. The generative designed frame has minimum displacement compared to traditional designed drone frame. It is observed that generative designing technique along with additive manufactured frames yields better frames with improved resistance to fracture and minimum displacement compared to traditional designed DJI flame wheel F450 drone frame.
Design of Dual Copter for Surveillance Applications
Authors: Balaji A , Mithil J , Jason Gousanal J
Published: January 2021

In this paper, an innovative design model of autonomous aerial vehicle is designed and fabricated with dual rotor setup. Nowadays, innovative unmanned aerial vehicles (UAVs) are widely required for surveillance, monitoring, data collection, reconnaissance and generally in places where humans face hazardous. In this model and design of UAVs, aero dynamic principles are adopted through reasonable design considerations and assumptions. Most of the researchers and academicians are currently pursuing research on AVs with various structures, wing designs, fabrication methods, controllers and materials to increase the efficeincy as well as for various applications. In this proposed work, an effort is made to design and fabricate the dual copter with wide moving ranges for surveillance applications in military intelligence system. This proposed design will be suited for all environmental conditions to collect the data as well as monitoring the system. Dual copter chassis are fabricated using 3D printer after the validation and analysis the proposed design using Solidworks CAD tool. The chassis are fabricated with the provision of space where the required sensors, actuators and controllers can be assembled. Lithium polymer batteries are employed to achieve the better performance for copter. The fabricated setup is integrated with radio frequency controller to achieve the flight control through RF transmitter. Hence the performance of the fabricated device is validated and analyzed through various performance measures of dual copter.
Modelling and Simulation of Autonomous Indoor Robotic Wastebin in Webots for Waste Management in Smart Buildings
Authors: Mohan Manju , Kuppan Chetty RM , Mohammed Azeem K. , Vishal P. , Poornasai B. , Sriram Vijayram
Published: January 2021

Waste bins are being used in an indoor environment by every common man for over many decades. Proper disposal of the waste and the waste collection system in an indoor environment is an important aspect of the cleanliness of the environment, the outlook of the environment, and as well as considering the health aspects of the people. An improper waste collection system in an indoor environment leads to a foul smell and unhygienic condition, thus inherently results in environmental pollution. Another crucial challenge is devising a safe navigation methodology for the smart waste bin in the indoor environment and efficiently model and simulate its performance. Therefore, in this paper, Mobile Smart Waste Bin with a smart waste collection system is proposed using the technical advancements in robotic technology with the navigation techniques. A simple line following navigation technique is employed in such a way that, when the waste bin gets filled with trash, the corresponding bin autonomously moves to the common collection point. This is done to analyse the integration of the physical and intrinsic characteristics of the system through simulation studies and the results are reported. The performance of the proposed indoor robotic dustbin bin is modelled with the underlying physics as well as the environment in webots virtual simulator. The effectiveness of the system is analysed through simulation studies in webots simulator and the results are visualized and reported. Thus, the designed mobile smart bin and proposed waste collection system will be a better autonomous solution compared to existing ones in the indoor environment of Smart Buildings.
Hexacopter design for carrying payload for warehouse applications
Authors: Aswath M. , Jeevak Raj S.
Published: January 2021

Airborne vehicles are gaining traction in research fields and in bringing it for commercial use. Multi-rotors for payload transport is one of the highly researched topics. In this paper, a hexacopter was prototyped based on commercially available components in the market and dynamic analysis was performed with constraints derived from ideal conditions, such as neglecting the effect of air resistance. The experiment shows the flight of the hexacopter to be stable with and without payload attached to it. Also, various computer vision methods were explored to detect and identify waypoints, in the form of gates, for the hexacopter to follow during its flight mission. The detection mechanism employed is HSV mask based filtering on input image and performing moment calculation on the extracted contour to determine the center of the gates. Localization of the drone with respect to the environment is performed with a monocular visual SLAM method known as ORBSLAM2.
Health monitoring of automotive clutch system by using Bayes algorithms
Authors: Chakrapani Ganjikunta , Sugumaran V
Published: January 2021

Clutch is an essential component in an automotive transmission system that helps in power transmission from the engine to the gearbox. Continuous operation of the clutch leads to degradation, damage, and reduced lifetime of internal components. Such factors can provoke the occurrence of various faults, which left unmonitored will result in clutch damage and seizure. Hence, continuous monitoring of the clutch is necessary to minimize unwanted breakdowns. This paper presents a condition monitoring technique based on vibration analysis to monitor the fault occurrence of different components. A machine learning approach is carried out to classify various faults. Such as fingers worn, pressure plate broken, pressure plate worn, friction material loss, and tangential strip bent. Feature extraction is performed on the acquired vibration signals using statistical learning process. The most important and significant features are selected from the extracted features by J48 decision tree algorithms. Further, feature classification is done with the help of Bayes based classifiers and the obtained results are compared to predict the best in class classifier for real-time.
A Bayes learning approach for monitoring the condition of suspension system using vibration signals
Authors: Arun Balaji P , Sugumaran V
Published: January 2021

The suspension system is an important component in an automobile, aimed to provide better comfort and good road handling characteristics during vehicle motion on uneven road conditions. Varying load conditions, prolonged operations, continuous road shocks absorption, and time-based degradation of internal components can create faults in a suspension system. Fault occurrences in the suspension system can damage the internal components that lead to malfunctioning of the system causes failure and endanger vehicle safety. Thus, condition monitoring has become an essential part of identifying fault occurrences in a suspension system. This paper is focussed on condition monitoring of suspension system using vibration signal analysis and faults are classified with the help of machine learning-based Bayesian classifiers. A test setup is fabricated to simulate the working of the suspension system under different load conditions with one good and six faulty conditions. Vibration signals are recorded and used to extract statistical features. Further J48 decision tree algorithm was utilized to identify the most significant features during feature selection process. Bayes classifiers such as NaiveBayes and BayesNet classifiers were used to find the type of fault occurrence from the selected features. The overall results of the aforementioned classifiers are compared and the best in the Bayesian classifier is suggested for real-time application.
Adapted wavelets by parameterization of wavelet bases for estimates of feature extraction of signals
Authors: Manju B R , Rajendran Athul
Published: January 2021

The work demonstrates the parameterization of filters coefficients of compactly supported wavelet to implement in the design of the best wavelet selection. The technique determines the best wavelet by means of a mathematical description and gives a representation in a single parameter for wavelets of finite length. The approach takes an input wavelet that is approximated to the best match. Through a choice of the parameter to adapt to the wavelet coefficients the perfect adaptation of the wavelet is achieved. For wavelet selection, the adaptive approximation carried out through parametrization addresses the challenge of visualization by setting up a Matlab programme that relies on the best selection with high potential to feature extraction of arbitrary signals.
Evolution in E-Commerce with Augmented Reality
Authors: Garg Navneet , Pareek Ankita , Lale Ajinkya , Jagannath Charya S K
Published: January 2021

New shopping methods with various attributes compared with traditional internet shopping can improve the administrations of business websites or E-commerce system. This paper is a dense abstract of the broadest parts of elective innovation dependent on AR collaborations that avoids the utilization of physical interaction with the product. The utilization of internet shopping has been developing significantly over some time. Augmented reality (AR) may assume the most significant job in improving the method of web-based shopping. The advancement of new AR innovation can be made valuable if it can imitate the highlights that have made web-based shopping the most favorable shopping source in present times. AR is equipped for working in a gadget utilizing Google’s AR Core or Apple’s AR Kit SDKs. It is a straightforward technique to create the 3D model before an individual that can be effectively equivalent which results in a better impression of the item by recreating in reality. 3D models are being delivered utilizing a game motor with AR SDKs in the client gadget which is controlled through a lot of projects written in an IDE. The execution of AR shopping is changing internet business by helping the web retailers to decrease the developing expense of profits and furnishing their clients with all the more captivating and advantageous approach to shop through their gadgets. Imaginative AR arrangements permit clients to envision their item continuously, from the comfort of their place. And it may play a major role in the industrial revolution with a specialization area.
Vehicle Accident Emergency Alert System
Authors: Sumathy B , Sundari L , Priyadharshini S Janani , Jayavarshini G
Published: January 2021

Today’s world is moving in such a speed that no person can spare a minute to stop and look what is happening. The rapid increase in population has inevitably increased the number of vehicles on road and more road accidents with life-loss. The report from World Health Organization (WHO) revealed that approximately 1.35 million people are losing their life each year, because of road accidents. The major reason for accidents is due to drunken driving, distracted driving, over speeding etc. Also, nearly 55% of the life-loss in the highways occurs due to the negligence of accident report of the passer-by vehicles especially during the night or in deserted places remain unnoticed till dawn. A person surviving from the accident, tends to lose their life due to lack of immediate medical response. A Vehicle Accident Emergency Alert system is proposed for immediate attention which could save their life. As soon an accident occurs the vibration sensor or the accelerometer present in the system, transmits the signals to Arduino controller. Latitudes and longitudes data are collected from the GPS system, passed using the GSM module to the emergency centre, and sends a text message to all the people listed in the emergency List. Getting the exact location would help the ambulance to reach the spot with shortest route and time. The proposed alert system could be implemented with less cost and incorporated in all vehicles in near future so that the rate of life-loss could be minimized.
A Low-Cost Portable Handheld System for Monitoring and Verification of Vehicle Documents
Authors: Vinod Vibin Mammen , Murugesan Govindasamy , Mekala V , Deepa D , Abinaya S , Bairavi K
Published: January 2021

The 2013 World Traffic Safety Status Report from WHO reports that more than 231000 people in India are killed annually in road accidents. Our research seeks to develop a system/portal from which we can track a person’s driving characteristics, such as traffic violation records, license details, insurance data, etc. Whenever residents refuse to comply with laws, a finger print scanner can help the police quickly access their records. Payment of penalty is initiated from his/her account immediately through a secured gateway. A two-level authentication and security scheme are employed such that the citizen would not have to compromise with their credentials. Whenever a citizen is caught breaking a law, the person’s biometric scan is carried out to open his e-License account with OTP which is available as an application. Account provides name, age, location, photo, information of license valid or not and amount has to be debited from bank account. This application can be easily used by police officers to avoid the citizens from breaking the rules. The proposed design is compact and portable and has been tested with a minimal dataset of 79 persons and found to provide satisfying results.
Smart Guidance System for Blind with Wireless Voice Playback
Authors: Sumathy B , Pavithran K M , Nizam N , Surya V A
Published: January 2021

The visually impaired/blind people face many challenges and seeks help from the other people even for their daily routine life due to various complications. Also, they could not go independently outside, even for their basic needs and mentally depressed due to their current inability. A wearable navigation system/device is proposed and developed to help the blind people as well as the partially blind people or challenged people. The devised unit/prototype consists of the displacement measuring sensor for the detection of the obstacles and depth. The data received from the IR and Ultrasonic sensor is feed into the Arduino UNO Microcontroller and it is processed. The output from the controller is given to the impaired people through the wireless voice playback modem, to alert them when they found obstacle or collision. The receiver end receives the corresponding current position values through the navigation systems and the static, dynamic condition of the impaired people is measured using mems accelerometer and the same information (latitude, longitude) is shared as SMS to their family members or guardian to monitor them, during any emergency. The proposed guidance cane is a cheap, simple, user friendly and smart device.
Study on Human Fingers Perception over Textured Surfaces for the Textural Applications in Haptics Technology
Authors: Ravikanth Dadi , Hariharan P.
Published: January 2021

Haptics technology uses skin as a source for feedback and helps in the perception of the stimulus. There are various types of actuators or displays used in haptics perception, like electro-tactile, vibrotactile, thermal coil and physical pins. These actuators require larger neural density for being used as an application. Hairy and Non-Hairy skin, its neural density pattern must be observed for perception memory applications. The textural applications in haptics technology are one of the kinds which use skin and its perception levels. The paper discusses the behaviour of fingertips and fingertip’s skin behaviour pattern towards textural applications in tactile feedback. The experiment in the paper uses psychophysical assumptions and single-blinded method of perception over six human participants under three environmental condition, and 10 stimuli which are used in everyday activity. The experimental result focuses on the perception time and perception memory of human fingertips, which will a comparative data with real-time haptic feedback. The experimental methods discussed in the paper addresses low-cost perception experiment for a preliminary study of haptics textural applications.
Semi-Autonomous Parking system for Automatic Transmission vehicles
Authors: Ohol S. S. , Kaware S.
Published: January 2021

This paper proposes an automated perpendicular parking strategy for a car which is to be designed. The design considers general cases of perpendicular parking for a rectangular body within a rectangular space. The system works in phases named: The Scanning phase, the parking environment is detected by ultrasonic sensors mounted on the extreme ends of body and a parking position and maneuvering path is produced if the space is enough. Then in the positioning phase, the model positions itself and get aligned with the parking space avoiding potential collisions. Finally, in maneuvering phase, the model moves to the parking position in the parking space in a specified path, which requires clutch, brake control, backward and forward maneuvers depending on the dimensions of the parking space. Based on the characteristics, a collision-free path is planned about the surroundings. The strategy is to be integrated into an automated parking system, and implemented in the car, showing capable of safe parallel parking in tight situations and as automated parking device to help vehicle drivers.
RETRACTED: Obstacle Avoidance Algorithms: A Review
Authors: Abhishek Talabattula Sai , Schilberg Daniel , Arockia Doss Arockia Selvakumar
Published: January 2021

It is only with time that the efficiency or the effectiveness of the algorithms for obstacle avoidance gets better, and experiences of any kind can be inferred for the betterment of the knowledge on this domain. For a mobile robot navigating its way from starting point to an ending point while traversing through deterrents, needs to divide the problem into sub problems. It fundamentally involves, sensory data interpretation, choosing apt algorithm based on the objective function, and configuring the mobile robot accordingly to attain desired output. In this paper, few essential classifications for obstacle avoidance and robot navigation algorithms are discussed. Importance of the hardware aspect of the robot is undeniable. A set of algorithms were classified into 2 main classifications which are further divided into sub classifications in an arranged and concise manner. This information can be used to develop a suitable model for the given problem. Understanding fundamental ideas or strategies would allow in developing a novel extended strategy, although few specialized strategies are saturated, nevertheless can still be used as valuable alternatives. These alternatives may involve algorithms which have paramount potential, per se which are interestingly similar to the functioning of a brain, nature-inspired, etc.
PSO Based Selective Harmonic Elimination PWM for Cascaded H-Bridge Multilevel Inverter
Authors: Sivagama Sundari M.S. , Periyasamy D.
Published: January 2021

A Single phase Cascaded H-bridge multilevel inverter topology fed by Photovoltaic source for the reduction of harmonics is proposed in this paper. Selective Harmonic Elimination technique is employed for elimination of 5th, 7th, 11th and 13th lower order harmonics and the particle swarm optimization algorithm is employed for estimating the switching angles. As a novelty, in order to maintain the power balance among the various sources, a cyclic selection procedure is adopted that over a period of operation also the sources equally contribute for the output power. MATLAB software is used for optimization and the results show the effectiveness of the proposed algorithm. The performance of the Particle Swarm Optimization Algorithm has been compared against the performance of the Genetic Algorithm.
Design and Simulation of Magnetic Levitation System
Authors: Maheedhar M , Deepa T.
Published: January 2021

This paper deals with the designing of magnetic levitation methodology depends on finite element method simulation. Sequences of simulations were performing, by changing the turn’s number of the coil and by varying the current passing through coil to construct the coil capable of generating the field of 0.6016T. From the simulation result it was found that by varying the number of turns of the coil and current passing through coil, magnetic field generation also varied to levitate the body.
Embedding Complete Bipartite Graph into Quadrilateral Snake
Authors: Leo Joshwa P , Berin Greeni A.
Published: January 2021

This paper deals with the technique that maps a guest graph into a host graph, known as Graph embedding. This tool is used in the simulation of interconnection networks. The exact wirelength of embedding complete bipartite graphs into quadrilateral snakes is considered as a research problem in this paper.
A Similarity Measure for Text Document Using Term Cardinality
Authors: Sumathi S. , Hannah Grace G.
Published: January 2021

With enormous development of digital technology, data is being generated at rapid rate with various application domains. Data has to be extracted or filtered to find useful information. A basic concept for these tasks and applications are the distance measures to effectively determine how similar two objects are. In this paper, a novel similarity measure for clustering text documents is proposed using the cardinality of the terms in the documents. The bench mark algorithm k-medoids is used for clustering task. The results obtained from the proposed distance measure are compared with other standard distance measures like Manhattan, Euclidean distance measure. Dunn Index is used to analyze the cluster validation of the results obtained from the distance measure.
Optimization of Harmonious coloring problem in Uniform theta graph and torus Network
Authors: Franklin Thamil Selvi M.S , Amutha A.
Published: January 2021

Coloring of graphs has been extraordinarily widened areas of investigation. A coloring of a graph can be depicted by a capacity that maps pieces of a graph into some plan of numbers commonly called labels or hues, all together that some property is satisfied. In this article we deal with the harmonious chromatic number of central graph of generalized uniform theta graph and torus network. A coloring c: V → ℕ of the nodes is a harmonious coloring if and only if the coloring is proper and for each and every line (e
1, e
2) ∈ E the line color (c(e
1), c(e
2)) is distinctive that is it emerge solely once.
Problematizing Hybridity and Third Place in The Immigrant
Authors: Caro Velma J , Alan G
Published: January 2021

The study purveys the hybrid nature of the first generation of settlers in The Immigrant. Manju Kapur has imbibed the bourgeois characteristics in the characters like Ananda, Dr Sharma and Nina. Identity crisis, a quest for self-identity and a contrast in Indian and Canadian style of living is predominantly evidenced in the novel, which leads to the idea of third place. This paper significantly identifies an unquenchable need for third places in the immigrants. The findings are of two parts: the first part identifies the hybrid qualities of the characters and the second part of the paper spots the need for third places in the characters. Further study correlates the characteristics of the Third Places with the places found in the novel by stating those as a source of elevation from the clutches of westernisation. The amalgamation of Hybridity and ‘Third Places’ theories dissect the novel whereby justifies the title of the paper.
A Study on Finite Difference Explicit Numerical Method of Symmetric Hyperbolic Partial Differential Equation
Authors: Sowmiya P. , Revathi G.K. , Sakthipriya M.
Published: January 2021

Explicit method approaches numerical analysis for obtaining numerical approximation to the solution in time dependent partial differential equation and ordinary differential equation which is required in computer application and physical processes. Mainly explicit methods are used to calculate the system at current time. Explicit method are very simple but not stable. Mainly in explicit numerical methods, parameters are calculated based on previous levels and also explicit solutions are independent to other values. For example the unsteady heat equation can be solved explicitly. The present paper is concerned with explicit numerical method of symmetric hyperbolic partial differential equation by using constant indices and also we proved the monotonical preserving values and also discussed the symmetrical hyperbolic partial differential equation with constant coefficients.
The Study of Advanced Scientific Experiments in Avatar- A Postcolonial Perspective
Authors: Vijayasekaran P. , Alan G.
Published: January 2021

Scientific advancement is used for the welfare of many people across the world. Even in the times of pandemic, the advancement of science has paved way for digital communication. But in this paper, an analysis is going to be made on how the humans had misused the scientific advancement to conquer a planet called Pandora in the movie Avatar to destroy the inhabitants of the planet who are referred to as Na’vi and to plunder a valuable natural mineral called unobtanium. This movie is an indirect adaptation of science versus nature, the argument to be made in this research paper is that nature is the base for everything, but people are deconstructing it with the scientific advancements, it is arguably like placing our own lives into misery. The question is that do we really need science for a happy life but the indigenous people in Pandora lived happily before the invasion of science in their planet, this is going to be further analysed in this research paper. The title emphasizes on the scientific advancement because this paper aims to discuss the impact of the advanced science that is depicted in the movie.
Embedding of Circulant Networks into Wheels
Authors: Mary Stalin , Rajasingh Indra
Published: January 2021

Circulant graphs have been studied over many years because of its vast applications in telecommunication industry. We find the minimum wirelengths of embedding the circulant graph G(n; ±{1, 2}) and G(n; ±{1, 2, …, j}) into variation of wheel graphs on n vertices in this paper.
Automated Detection of Diabetic Retinopathy Using Intuitionistic Fuzzy Digital Convex Envelope Segmentation Algorithm
Authors: Meenakshi S. , Amsini P. , Uma Rani R. , Amsaveni D.
Published: January 2021

Diabetic retinopathy is an ailment of the retinal vessels, which progresses about in most of the diabetes mellitus patients with high blood sugar levels. A framework for automated detection of disorders of the retinal vessels is proposed and examined in this article. As intuitionistic fuzzy sets are being defined through membership and nonmembership functions, they play a vital role in digital image processing to detect the disorder part more clearly. Moreover, shape is a crucial one in numerous areas such as object identification, detection, geomorphology and biology characterization. The intuitionistic fuzzy digital convex envelope is used to measure and analyze the shape of the image of the affected part. The various stages concerned in the process are image acquisition, preprocessing and segmenting the disorder region by the new proposed intuitionistic fuzzy digital convex envelope algorithm. Foremost, this automatic segmentation method reduces the manual work errors and time consuming.
Effect of acid on the early strength of aluminum sulfate series alkali-free accelerator
Authors: Wang Liya , Cai Guisheng , Gong Yukun , Liu Jun , Lu Tongwei
Published: January 2021

This article introduces the effect of acid on the setting time, early strength and stability of aluminum sulfate alkali-free accelerator. The inorganic acids used are phosphoric acid, hydrofluoric acid and fluorosilicic acid, and the organic acids are oxalic acid and ethylenediaminetetraacetic acid. As a result, it was found that increasing the amount of acid can increase the stability of the accelerator. The product of the anion in acid and calcium ion in cement is easy to form. The product damages the network structure of the cement paste, and the early strength is low.
Effects of temperature and water-to-cement ratio on autogenous shrinkage of oil well cement
Authors: Pang Xueyu , Sun Lijun , Santos Araujo Socorria Dos , Bu Yuhuan
Published: January 2021

The chemical shrinkage and corrugated tube test methods were used to study the shrinkage behaviour of Class G oil well cement with water-to-cement (w/c) ratios of 0.3 and 0.5, cured at temperatures from 15 to 60°C. The experimental results show that the typical linear shrinkage evolution curve of a cement slurry obtained by corrugated tube method have an obvious inflection point, beyond which the linear shrinkage increase is close to zero. The time at which the inflection point is observed decreases significantly with increasing curing temperature, but varies very little with w/c ratio. The inflection time also shows approximately linear correlation with the setting time of the cement (The two are almost equal for w/c=0.3). The degree of hydration corresponding with the initial and final setting time were estimated based on chemical shrinkage test results and the relationships between estimated volumetric bulk shrinkage and chemical shrinkage were analyzed.
Effect of various testing parameters on the experimental evaluation of oil well cement cured under simulated downhole conditions
Authors: Qin Jiankun , Pang Xueyu , Liu Zhongfei , Ai Zhengqing , Li Ning
Published: January 2021

It is well known that regular oil well cement systems experiences strength retrogression at curing temperatures above 110°C and silica sand is typically added to mitigate strength reduction. However, due to the complex experimental procedures associated with high temperature and high pressure curing of oil well cement specimens in the laboratory, historical test data tend to suffer significant uncertainties. A comprehensive study of the various influencing factors on the physical and mechanical property test results of oil well cement system cured under 200°C is conducted here. The specific influencing factors investigated include curing time (from 14d to 69d), depressurization rate, curing pressure (50MPa vs 150MPa), specimen size (diameter of 25mm vs 50mm) and curing autoclave design. The property of the set cement evaluated include strength and modulus, permeability, indentation modulus and hardness, etc. Test results suggest bigger specimen size and faster depressurization rate may lead to significant specimen damage, causing experimental artifact. Different autoclave design may also lead to significant differences in the mechanical property of the set cement even under the same curing temperature and pressure.
The effect of the thickness of steel pipe in linear and 2-dimensional stiffness analysis during design of transmission tower
Authors: Song Yuxi , Chen Xianqi , Di Zijian , Sun Yihang
Published: January 2021

Transmission towers are truss structures which are used to support the transmission power lines. It is important to design the transmission towers because unsuitable dimensions could waste the steel or lead to the failure of transmission towers. The thickness of the beam is a critical parameter during the design of transmission tower, which is directly related with the safety of the transmission tower. In this paper, a finite element method in linear and 2-dimension was employed to simulate the mechanical behaviour of transmission tower. Based on the calculated results, the variations of the maximum stress and the maximum displacement with the increasing thickness were displayed. Both the stress and displacement decrease dramatically with the increasing thickness and reach to a stable value if the thickness is beyond a critical thickness. When the thickness changes from 1 mm to 4 mm, the maximum stress and the maximum displacement decrease by 74%. When the thickness is more than 4 mm, the reduction of stress and displacement is not obvious. The percentage reduction of more than 70% is determined to be the criterion for optimum thickness. The relationships can be used in the design of the transmission tower.
Foaming effect influence of PBT / ABS resin as a reducing agent in foamed asphalt
Authors: Huang Ming , Chen Hongpo , Shi Xiao , Wen Xuejun
Published: January 2021

Foamed asphalt provides good environmental protection characteristics and economy. The utilization rate of old materials in foam asphalt recycling technology is higher than that of emulsified asphalt. Due to the lack of performance, the application scope of foam asphalt recycling technology is limited. In order to maintain high utilization rate of recycled asphalt concrete and improve the performance of foamed asphalt mixture, it will be the focus of research. In recent studies, adding a reducing agent into the regeneration process of foamed asphalt is a new technology. According to the test results of reduction performance of asphalt SARA four components, the PBT/ABS resin (Acrylonitrile butadiene styrene modified by Polybutylene Terephthalate) has excellent asphalt reduction effect, and PBT/ABS resin has good compatibility with emulsified asphalt after emulsification. Therefore, based on the existing foaming theory, the influence of asphalt temperature and water consumption on asphalt foaming with PBT / ABS resin reducing agent was designed. The influence of asphalt temperature and water consumption on foamed asphalt modified by PBT / ABS resin reducing agent was discussed. The results show that the PBT/ABS resin has larger foam volume than ordinary foam asphalt, but the average diameter of foam is slightly smaller. Similar to ordinary foamed asphalt, expansion rate and half-life are opposite to that of water consumption. Water consumption and asphalt temperature have significant effects on foaming effect. At the same temperature, with the increase of water consumption, the expansion rate increases and the half-life decreases. Under the same water consumption, the higher the foaming temperature, the greater the expansion rate. However, when the temperature reaches 160 °C, the expansion rate of asphalt does not vary with the temperature. With the increase of temperature, asphalt with different temperature has different optimal foaming water consumption. Finally, the optimum foaming conditions of PBT/ABS resin foam are given as follows: the best foaming temperature is 140 C, the water consumption is 3.8%, the ultimate expansion rate is 21.5%, and the half-life is 22.5s.
Study on non-destructive reinforcing material of modified one component polyurethane for tunnel crack disease prevention
Authors: Wang Zhiwei , Ma Weibin , Ma Zhaohui
Published: January 2021

In view of the defects of tunnel lining structure such as cracking and block dropping, cavity behind, honeycomb and pitted surface, construction joint dislocation and other defects, the technical research direction for non-destructive reinforcement materials in tunnel is proposed. The polyamide curing coating agent and one-component polyurethane protective material with high adhesion, good elongation, large tensile strength and rapid drying are developed. The above materials are described The application technology and key points of brush coating, rolling coating and scraping coating can provide reference for related engineering application.
Rapid prototyping of PDMS microdevices via µPLAT on nonplanar surfaces with flexible hollow-out mask
Authors: Yan Shiqiang , Wang Shuting , Hao Zhujing , Liu Meimei , Miao Chunyue , Alam Md. Fazle , Bai Ruihan , Li Linmei , Luo Yong , Liu Tingjiao , Lin Bingcheng , Zhang Weijia , Lu Yao
Published: January 2021

A major goal of polydimethylsiloxane (PDMS) microfabrication is to develop a simple and inexpensive method for rapid fabrication. Despite the recent advancements in this field, facile PDMS microfabrication on non-planar surfaces remains elusive. Here we report a facile method for rapid prototyping of PDMS microdevices via µPLAT (microscale plasma-activated templating) on non-planar surfaces through micropatterning of hydrophilic/hydrophobic (HL/HB) interface by flexible polyvinyl chloride (PVC) hollow-out mask. This mask can be easily prepared with flexible PVC film through a cutting crafter and applied as pattern definer during the plasma treatment for microscale HL/HB interface formation on different substrates. The whole process requires low inputs in terms of time as well as toxic chemicals. Inspired by liquid molding, we demonstrated its use for rapid prototyping of PDMS microstructures. Following the proof-of-concept study, we also demonstrated the use of the flexible hollow-out mask to facilitate cell patterning on curved substrates, which is difficult to realize with conventional methods. Collectively, our work utilizes flexible and foldable PVC film as mask materials for facile microscale HL non-planar surface modification to establish a useful tool for PDMS prototyping and cell patterning.
Effect of photon statistics on vacuum fluctuations based QRNG
Authors: Dandasi Abdulrahman , Ozel Helin , Hasekioglu Orkun , Durak Kadir
Published: January 2021

The speed of quantum random number generators (QRNGs) is a major concern for practical applications. In this work, we introduce scattering as a method to enhance the randomness characteristics of the entropy source. This method allows optical bit extraction with a faster sampling rate without compromising the randomness quality compared to the coherent source based balanced homodyne detection. Scattering is a probabilistic phenomenon which increases the chaotic behaviour of coherent sources. It broadens the distribution of photon statistics and makes it super-Poissonian. We show that a signal with super-Poissonian distribution has better randomness compared to a Poissonian one, indicated by their autocorrelation characteristics and the randomness test results. The use of scattering mechanisms as an entropy source eases the miniaturization of QRNGs, it also makes them compatible and adaptable to existing technologies.
Synchronous growth of 30°-twisted bilayer graphene domains with millimeter scale
Authors: Liu Jingbo , Wang Zegao , Ling Dongxiong , Wei Dongshan , Lv Wei , Kang Xiaojiao , Qi Fei , Ding Shujiang , Hao Xin , Li Pingjian , Chen Yuanfu
Published: January 2021

Bilayer graphene (BLG) with 30°-twist (30°-tBLG) has been proven to possess a quasicrystal structure potentially providing novel applications. Despite the growth of BLG, especially the AB-stacking bilayer, has gained great attention, the growth of 30°-tBLG has been rarely achieved. Herein, for the first time, the decaborane-assisted synchronous growth of millimeter-sized single-crystalline 30°-tBLG was achieved on Cu foil by controlling the nucleation density and growth kinetics of graphene during chemical vapor deposition using diluted methane gas as the carbon source. The synchronous growth kinetics and decaborane-assisted co-catalysis mechanism are revealed by monitoring the growth process from the initial stage of graphene seeds to the millimeter-size scale. A 30°-tBLG based field effect transistor was fabricated and was found to possess a field-effect carrier mobility as high as 3671.3 cm2 V−1 s−1 at room temperature. Thus, this work provides a new strategy to grow high-quality and large-scale 30°-tBLG domains which will facilitate their application in the quasicrystal field.
Biological impact of dosimetric perturbations of a fiducial marker and the daily number of fields in proton therapy for prostate cancer
Authors: Sagara Tatstuhiko , Kato Takahiro , Murakami Masao
Published: January 2021

The purpose of this study was to estimate the biological impact of dosimetric perturbations of a fiducial marker and the daily number of fields in proton therapy for prostate cancer. Using a linear-quadratic model, normalized total doses (NTDs) of points where deposited dose was reduced from the prescribed dose by dosimetric perturbation of a fiducial marker were calculated in two hypothetical prostate cancer treatment schedules: a) irradiation of both parallel-opposed lateral fields and b) irradiation of alternate field in each daily treatment. The impact of hypofractionation and sublethal damage repair between irradiation on NTD was also estimated. The NTD of two fields/day schedule becomes lower than that of one field/day schedule. The difference becomes larger as dose reduction from one of two fields becomes more enhanced. The NTD reduction from the total dose in the two fields/day schedule is largest (30% of total dose) where the dose from one beam is completely lost by a fiducial marker. In contrast, the NTD reduction from the total dose in the one field/day schedule is largest (9% of total dose) where the half dose from one beam is decreased by a fiducial marker. In addition, the NTD reduction becomes larger as the fractional dose increases in a hypofractionated regimen, and when the effect of sublethal damage repair was incorporated. These influences become significant in prostate cancer since the radiobiological sensitivity α/β of prostate cancer is lower than other cancer types and normal tissues late complication. Treating with one alternate field in a daily treatment can improve a deteriorating treatment effect by dosimetric distortion of a fiducial marker in prostate cancer treatment. However, the choice of the number of beams in a fraction must also be determined by considering the sparing of normal tissues and patient-specific status.
Synthesis of urea-modified magnetic nanocomposites iron oxide/carbon as a potential biomaterial produced by arc discharge in liquid medium and its in-vivo toxicity assessment
Authors: Saraswati Teguh Endah , Sari Fitri Nela , Patimah Patimah , Handayani Nestri , Herbani Yuliati , Nagatsu Masaaki
Published: January 2021

Carbon-encapsulated magnetic nanoparticles are promising candidate materials for drug-delivery applications. However, due to their hydrophobic and aggregation properties, which indicate lower biocompatibility, proper surface modification of the carbon-based material is required. In the present study, we present the facile route to producing biocompatible magnetic nanocomposite iron oxide/carbon using the liquid medium arc-discharge method. The medium used was ethanol 50% with urea added in various concentrations. Using x-ray diffraction (XRD), the nanocomposite produced was confirmed to have a crystalline structure with distinctive peaks representing iron oxide, graphite, and urea. Fourier transform infrared spectroscopy (FTIR) analysis of the nanocomposite produced in ethanol/acetic acid or ethanol/urea medium shows several vibrations, including Fe–O, C–H, C–O, C=C, C–H, O–H, and C–N, which are intended to be the attached aromatic oxygen- and amine-containing functional groups. The nanocomposite particle was observed to have a core–shell structure that had an iron-compound core coated in a carbon shell possibly modified by polymeric urea groups. The presence of these groups suggested that the nanocomposite would be biocompatible with biological entities in the living body. Lastly, the prepared nanocomposite Fe3O4/C-urea underwent an in-vivo acute toxicity assay to confirm its toxicity. The highest dose of 2000 mg kg−1 BW in this study caused no deaths in the test animals even though cell damages were observed, especially in the liver. This highest dose is considered a maximum tolerable dose and is defined as practically non-toxic.
Study of 6,8He+p elastic scattering at 25–73 MeV/nucleon
Authors: Al-Shammari Amsha Q S , Madani Jamal H , Alvi M A
Published: January 2021

In this work, p-6,8He elastic scattering differential cross sections in the energy range 25 ∼ 73 MeV/nucleon have been studied by applying the Coulomb modified Glauber scattering formalism. Three different density distribution models for proton and neutron densities have been used in calculating the differential cross sections. With the Bhagwat, Gambhir and Patil (BGP) nuclear density model, the calculated rms matter radius for 6He is found to be 2.49 fm which is larger than the experimental value 2.33 ± 0.04 fm while, for 8He it comes out to be 2.47 fm which is close to the experimental value 2.45 ± 0.07 fm. In general, the comparative analyses of the elastic scattering cross sections with different density models indicate that the calculation with BGP model density is qualitatively more successful to reproduce the p-6,8He experimental data. We emphasize that within the analyses no adjustable parameters are employed to fit the available experimental data. By varying the parameters of the spin-dependent amplitude, a very close agreement has been obtained in a simultaneous χ
2-fitting to the polarization data for p-6He elastic scattering measured at 71 MeV/nucleon. The total reaction cross sections for p-6,8He at these energies have also been compared with the corresponding cross sections obtained reported in earlier studies.
Analysis of interference microscopy in the spatial frequency domain
Authors: Lehmann Peter , Künne Marco , Pahl Tobias
Published: January 2021

If high numerical apertures are used in coherence scanning interferometry, an extension of the interference signal’s spectral distribution to lower frequencies can be observed. Depending on the slope of the measured surface interference signal contributions belonging to higher frequencies will vanish. In addition, the high spatial frequency information of a measured surface structure will contribute to the low frequency components of the spectrum of the measured interference signals. These effects can be explained by analyzing both the measuring object as well as the transfer characteristics of the interference microscope in the 3D spatial frequency domain. In this study we analyze the mentioned effects based on Kirchhoff’s diffraction theory in the spatial frequency domain introducing the double foil model. The model explains why the choice of the wavelength, which is used for signal analysis, shows a substantial impact on the reconstructed topography. As a consequence, careful analysis of the 3D transfer function based on the Ewald sphere model enables a better understanding of the measuring process, the lateral resolution capabilities, and the improvement of the measurement results by choosing adequate signal processing parameters.