bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Squeeze Casting Process Parameter on Al/SiCp Metal Matrix Composite
Authors: Gurusamy P , Hari Krishna Raj S
Published: December 2020

There are so many casting processes available in the manufacturing industry world. Each method has its distinguished pros and cons. The main drawback of the conventional casting process, such as high pressure die casting, is the presence of air, wrinkles and porosity. Casting without these defects is really challenging and leads to tailor the new innovative processing method. To develop the quality and integrity of the process the suitable technique is considered as squeeze casting. This method is versatile and exhibits unique properties since many automobile manufacturing industries have incorporated it. Squeeze cast component can have superior mechanical, micro, and microstructural characteristics of features compared with traditional casting techniques as it alleviates voids and blowholes. The current study focuses on the effect of process parameters of squeeze casting towards the mechanical properties of Al/SiCp materials. Volume addition of 10% SiCp to the molten aluminum metal to pour into the preheated die is performed in the laboratory. Cylindrical cast samples are cut into pieces as per the dimensions to carryout material characterization.
Graphene doped spray dried ceramic nano oxides for high capacity battery electrodes
Authors: Singh Mansi , Joshi Poorva Nitin , Vattappara Kevin , Reghu V R , Ramaswamy Parvati
Published: December 2020

Electric vehicles or portable electronic devices have come to rely heavily upon electrochemical devices, such as rechargeable batteries with optimum charge discharge characteristics, current ratings, charge-discharge rate (rate capability), cyclability etc. to perform under the expected service conditions. One of the goals of a rechargeable battery materials researcher is to fabricate materials to realize solid-state batteries with high reliability and lithium–air batteries with ultimate capacities. Most of the materials although possess high theoretical energy density values: invariably suffer from inferior cyclic performance. The performance of these batteries is guided by the electrodes within these devices which in turn depend upon the materials used to fabricate them. Chemical composition and its uniformity, consistency in microstructural features, and adequate choice of various layers that may be in the form of coatings to be overlaid on the base materials mostly comprised of ceramic oxides such as oxides of Li doped with niobates, manganates, vanadate etc. with carbon or graphene coated over layers to provide with the suitable interfacial conductivity as electrode materials in Li-ion batteries. The interfacial layers and the mechanism of interfacial phenomena encompassing the grains play a significant role in determining the performance. Optimum microstructure is obtained by choosing the right processing equipment and spray drying the composition in slurry form provides the most optimum solution. Further, spray drying offers high potential for a transfer from a lab scale technology to industrial level extrapolation. In this paper, nano graphene has been spray dried along with nano alumina grains in water media and polyvinyl alcohol binder to ascertain the free flowability, consistency in formation of graphene over layer on alumina grains as well as uniformity in graphene on alumina composition. The free flowing spray dried graphene coated alumina powders were analysed via SEM, EDS and XRD and results are presented. Additional information based on a review conducted on published information on most popular compositions in terms of electrode materials such as in Li-ion, sodium-ion etc have also been included. In the review section the rapidly increasing literature on spray drying of solutions and suspensions are also included.
Estimation of Crystallite Size, Lattice strain and Micro Residual Stresses by FWHM method and impact of Feed rates on Residual stresses
Authors: Kumar Aneesh
Published: December 2020

The prediction and control of residual stresses of machined components is necessary. The tribological properties such as wear and tear are get influenced by it. The analytical assessment of residual stress profile of mechanically micro machined specimen with XRD (X Ray diffraction) technique are proposed. Also the lattice strain and crystallite sizes for different specimens were assessed. Residual stresses and feed rates are found significantly correlated and gets affected for Low Carbon Steel Specimensduring micro milling.
Synthesis and Characterization of Carbon Nanotube Hydroxypropyl Methylcellulose Composites
Authors: Singh Pradeep Kumar , Goyal Monika , Yadav Rajat , Sharma Aman
Published: December 2020

In tissue engineering especially, aqueous injectable, untouched gel- forming systems, possessing variety of advantages has been an attention seeker for the industry when compared to scaffolds. In-situ gel forming matrix can be introduced easily to the defect sites through needle, because of which surgical implantation can be removed first. Secondly, the ease of conformity upon introducing on the surroundings, and introducing easily on cells, and can be introduced as therapeutic agents and growth factors by simple mixing, without any afflict about residual solvents commonly used in scaffolds, when combined. For which, Multi-walled Carbon Nano-tubes has been acid functionalized which then covalently grafted on Hydroxypropyl methylcellulose (HPMC) by the Oxidized Carbon Nano-tubes, to form acylchlorinated carbon nano-tubes which has been firstly reacted with thionyl chloride and later dispersed in HPMC to form composite material, MWCNTs – HPMC, several time has been washed multitudinous to eliminate not reacted materials. FT-IR, TGA, SEM and TEM are used for the characterization of the composites, and which shows that it exhibits enhanced thermal stability.
Extraction of Bioactive Nano Particles from Seaweed for Heavy Metals Removal and Antibacterial Agent
Authors: Sharma Vikash Kumar , Singhal Piyush
Published: December 2020

The environmental impact and building up toxicity of heavy metals have been a cause of great concern in recent years. This has given rise to a significant increase of studies with the objective of effectively developing alternative technologies for the removal of substances from industrial effluents that are potentially noxious to the environment. Biosorption can be a piece of the arrangement. A few sorts of biosorbents, for example, ocean growth, molds, yeasts, microorganisms or crab shells are instances of biomass tried for metal biosorption with empowering results. Ocean growth offer points of interest for biosorption on the grounds that their naturally visible structures offer an advantageous reason for the creation of biosorbent particles appropriate for sorption process applications. In the present paper a detailed study has been carried out to find a suitable bionano absorbent extracted from various seaweeds which is abundantly available in the coastal area of Thondi and characterized by UV and FTIR and TEM techniques.
Nanotechnology in Automobiles - A OEMS Viewpoint
Authors: Singh Pradeep Kumar , Goyal Monika
Published: December 2020

For the development of the societies into modern world, people have a very basic need that is mobility. And in this context automobiles do have a very vital role to play. By 2030, vehicle tally must reach upto“1.5 Billion” approx. utility and passenger vehicle, when estimated worldwide. As the number of vehicles would increase so as the energy demand worldwide also as resultant would be increasing. Related to this many more challenges arose regarding cumber in safety of passengers, curtailment of pollutants, traffic guidance system, efficacious recycling of life of the vehicle so that the scant resources can be saved significantly. Considering this, for automobile manufacturers a large number of opportunities are getting generated. For future needs sustainable advantages of mobility can be achieved because of which OEMs are aiming their efforts by acclimatizing the comfort ability, safety and environment friendliness.

Nanotechnology can assume a huge job by adding to the fundamental developments and production of creative materials and processes in the automotive field. Auto OEMs look to the domestic industry to use the unique innovation potentials of nanostructured materials, thereby protecting and expanding their own position. It appears that the opportunities offered by nanotechnology has not been tapped sufficiently yet. There is a need for the domestic enterprises, the auto industry & research institutions to work together to identify and initiate necessary innovation processes through nanotechnology. The paper is an endeavor to distinguish the assortment of applications for nanotechnologies in the automotive space from an auto OEM point of view and investigate the financial and technical potential to additionally develop them.
Numerical investigation of frame for human powered flywheel equipped cycle rickshaw
Authors: Tadele Fikru , Velmurugan P.
Published: December 2020

Recent awareness in fossil fuel depletion due to large consumption with regard of population number growth from time to time, and environment degradation due to fossil fuel combustion emission has generated. This research focuses on the design of human powered flywheel equipped cycle rickshaw. The operating mechanism of this vehicle is same as the upright bicycle. The study conducted by reviewing different related previous works. The main objective of this work is designing flywheel equipped cycle rickshaw, to harvest kinetic energy lost during braking or slow down for later use. This done by using a mechanism incorporated with flywheel and clutch system. The study is carried out for design of the frame. The frame of this work cycle rickshaw designed by using both up right bicycle fit data and anthropometrics data in order to develop ergonomic and rigid frame. After the needed component geometry and dimension analyzed the model of cycle rickshaw components developed by using CATIA software. The design considers both static and dynamic condition. For FE analysis ANSYS 15 is used to find out total deformation, equivalent (von mises) stress, maximum shear stress and factor of safety.
Ergonomic Evaluation of Passenger Car Vehicle Seat Design
Authors: Deepak Suresh Kumar R , Ravi S , Vignesh A , Sujith Raja M S
Published: December 2020

Automotive seats are one of the most significant parts of vehicles and customers desires for comfort in vehicle seats in recent years. In the automotive field, the solace of the traveler, just as the driver, is to be guaranteed. Inappropriate and different contemplations may prompt forces a tremendous measure of stress in the driver over a while. If the seat of the driver isn’t satisfactory, then the performance of the driver may lessen and it might prompt exhaustion and another musculoskeletal issue, ultimately causes an accident to the driver just as the traveler. Aside from this, the inconvenience may happen on account of inadequate space in the lodge, drivers see, reachability etc. Hence, by considering different parameters an examination is performed and given the accompanying. The comfort analysis of passenger car seat was done by utilizing the DELMIA software and the appraisal is broken down. The manikin is made in such a manner according to the Indian standard life structures and the investigation is completed with 95 percentile man and 5 percentile female estimations of Indian manikin.
Recent developments in Polymer Matrix Composites – A review
Authors: Ravichandran M , Balasubramanian M , Anand Chairman C , Pritima D , Dhinakaran V , Stalin B
Published: December 2020

This paper presents the recent developments in polymer matrix composites (PMC). Polymer-based composites are widely used materials since the materials have good mechanical properties with low density. Polymer-based materials are used for many applications such as the aerospace industry, automobile industry, sports equipment, construction, and packaging industries. Recently nature fibers have been used as reinforcement materials to synthesize PMCs effectively. Polymer-based materials have been used in biomedical applications. This paper displays the summaries of synthesis, microstructure, and properties of recently reported various PMCs.
Investigation and optimization of Superplastic forming parameter in Aluminium alloy
Authors: Balasubramanian M , Anand Chairman C , Marichamy S , Dhinakaran V , Stalin B , Ravichandran M
Published: December 2020

Super plasticity is the capability of materials to parade very high tensile elongation which can be more than 2500%, appearing in eminent temperature under low stress dependent on strain rate. In this paper intentions to optimize superplastic parameters such as yield stress, ultimate stress, temperature, strain rate and strain rate sensitivity index by using hot tensile test method in AA 7075 alloy in experimental and numerical simulation method. In experimental method, the cross head velocity concept has been adopted to attain the permeability by achieving the material properties with the functions’ of temperatures conditions. Finite element method using ABAQUS software was modeled to compare the experimental results.
The squeeze casting parametric effect on magnesium metal matrix composite
Authors: Vairamuthu J , Tilahun Samuel , Vijayakumar M D , Ramesh Kannan C , Manivannan S , Stalin B
Published: December 2020

The reinforced Metal Matrix Composite (MMC) was broadly used in various engineering applications. The light weight and high strength metal matrix components were used in aerospace and automotive applications. The silicon carbide, boron carbide, aluminum oxide and carbon fiber were used as common reinforcement materials. The magnesium and its alloys were recently has a maximum role in MMC due to its high strength and light weight. In addition to the magnesium, the aluminium and copper was included through the reinforcement of boron carbide (B4C). It was formulated through squeeze casting technique. The copper has good electrical conductivity and it has more corrosion resistance. The magnesium metal matrix was fabricated through squeeze casting technique. The Vickers hardness was determined through the different input squeeze casting factors such as pressure, pouring temperature and die temperature. The Response Surface Methodology (RSM) optimization was used to analyze the parametric effects.
A Review On Ultrasonic Welding of Various Materials and Their Mechanical Properties
Authors: Tilahun Samuel , Vijayakumar M D , Ramesh Kannan C , Manivannan S , Vairamuthu J , Manoj Kumar K P
Published: December 2020

In recent years, in contrast with conventional welding methods, ultrasonic welding has been one of great importance among its relevant applications and materials. The bonding of different materials is always difficult, as the unregulated scale of the grain and the fragile mechanical properties are different than conventional welding techniques. In addition, this research paper offers numerous explanations and uses of the ultrasonic welding technique on different materials and its alloys such as aluminium, steel, titanium, nickel, magnesium and also on fiber reinforced composites and thermoplastics along with their mechanical properties. The key benefits of this method are also discussed such as clean and undamaged welding on outer sections, reliable and solid bonding, and saves time effectively.
Design, Implementation & Performance Analysis of Solar Tracking System on Simulink Platform
Authors: Mamodiya Udit , Tiwari Neeraj
Published: December 2020

This paper presents the idea of tracking framework which was executed on Simulink stage. The variety in current and voltage for static and tracking SPV power plant are appeared in this paper. The relative study at various situating of panel (static force plant) is additionally appeared in this paper. The entire model like sun tracking model, static SPV model, LDR sensor model, DC motor model additionally appeared in the paper. The primary goal of this paper is to break down the outcomes concerning static force plant. The tiltaion edges are 30°, 60° and 90° static force plants. The simulation results and the impact of tiltation point are additionally introduced in this paper. In the closing comment, the improved effectiveness because of tracking method is appeared.
Optimization of Wear Parameters of aluminium composites (AA6082/12wt%ZrO2) utilizing Taguchi technique
Authors: Mohanavel V , Ramesh Kannan C , Vairamuthu J , Stalin B , Balaji R , Rajarajan S , Ganeshan P
Published: December 2020

Optimization of the wear properties of AA6082/12%ZrO2 AMCs prepared through compo casting process using Taguchi’s S/N analysis was evaluated. Taguchi’s process was utilized and L9 orthogonal array was elected for behaving the wear tests. Optimal process parameters are estimated to eliminate the wear characteristics of the composite. Moreover, the effect of ANOVA also demonstrates that the sliding distance, the applied force and the sliding velocity have an essential function in the reduction of wear (gram). The values of the tests are consistent with the methodology of Taguchi.
Performance Consideration and Result Analysis Using Various Alternative Refrigerants in a Vapour-Compression Refrigeration System
Authors: Dhivakar Raviram R P , Vijayaganapathy D , Dhinakaran V
Published: December 2020

The performance consideration of various refrigerants such as R22, R134a, R410a and R290 are considered and the various properties of the refrigerant are considered. The experiments are conducted in Vapour compression refrigeration system based AC test rig with the selected refrigerants. The power consumption is calculated with no loads and various load conditions such as 100W, 200W, 300W &400W are monitored and recorded and the graph is plotted to attain the selection of refrigerant. The theoretical and actual COP is calculated using the standard formula and it is plotted with various load conditions. The selection of refrigerants R22 is selected based on the results.
Review on 3d Printing of Biological Tissues and the Materialization
Authors: Adharsh S. , Abul Kalam Azad A. , Fahmidha Fathima Yasin , Dhinakaran V. , Jagadeesha T.
Published: December 2020

3D printing is one of the recently evolved manufacturing techniques which has wide range of applications in engineering, education, art and science. Bioprinting is the recent advancement of additive manufacturing process in the area of medicine. It is a process which involves layering and curing of biological cells or tissues and turning it into a fully functioning organ or hard supports(bones). It has solved the problem of shortage of organs for transplantation. It would be very difficult to find the right organ according to the needs of a particular person but this recent advancement has given a right solution for it. Bioprinters typically uses bioinks which dispenses through the nozzle of the printer for deposition, and a dissolvable hydrogel is used in order to protect and support the tissues of the organic material. This type of printing is done in lab environment only under a controlled system.
Design and Analysis of Sliding Mode Control for Battery Charging Applications
Authors: Sivaraman P , Logeswaran T , Sakthi Surya Raj J S , Boopathimanikandan S
Published: December 2020

In Electric Vehicle (EV) charging stations connected loads are intermittent due to continuous variation of charging level battery. In this situation, the linear controller like P, PI, and PID does not offer a quick and good transient response to the EV charging converter. In some cases, EV charging stations push to instability region for abrupt change in loads. Therefore, this research work focused on investigation of non-linear controllers for EV battery charging station. This paper investigates the performance of Hysteresis Controller (HC) and Sliding Mode Controller (SMC) for EV charging station under dynamic load conditions. The hysteresis controller and sliding mode controller are developed for buck converter fed EV charging stations and its performance is analyzed using pole zero plot and bode plot methods. From the investigation it is found that SMC offer optimum gain margin and phase margin under dynamic load condition for EV charging station.
Iterative Learning Control for a Repetitive 2D Process
Authors: Muthumari S , Gomathi V , Srimathi R , Eswaran Kishore , Kamatchi Kannan V
Published: December 2020

To control the systems which operate in a repetitive mode is known to be a difficult task. For example, systems like robotic manipulators are used for doing the repetitive assigned task. This can be overcome by the iterative learning control (ILC) method. In this article, the DC motor model is discussed for controlling the speed of the motor by the design of an ILC algorithm, and its performance is compared with the conventional PID algorithm. The ILC algorithm is implemented for the minimum and non-minimum phase systems. The resulting response, absolute and integral absolute errors are plotted. The Z-N tuning method is used to implement PID control. The performance of the DC motor has been evaluated by comparing the Integral Square Error (ISE), Integral Absolute Error (IAE), and Integral Time Absolute Error (ITAE) with the conventional PID controller.
Vibration Based Piezoelectric Energy Harvesting - A Review
Authors: Pradeesh E. L. , Udhayakumar S. , Vasundhara M. G. , Vadivel Vivek V.
Published: December 2020

In this digital race, electronic equipment has been integrated into human beings as a part of their body. Some electronic equipment is connected by wires, while some are self-powered by batteries. Today the ultra-low-power smart electronic gadgets and smart wireless sensor devices need an unlimited battery for enhancing the performance. In a remote area such as forests and hill areas, conventional charging methods of batteries by wire is not possible. Supplying power through wires is difficult. To overcome this, a sustainable solution is energy harvesting. The renewable sources for energy harvesting are light, heat, wind, tidal, motion, and vibration. Researchers have more interest in harvesting energy through mechanical vibration due to its abundant availability. This paper reviews the work about piezoelectric crystals and their role in energy harvesting, simulation software used, energy harvesting circuits and storage devices.
Design And Development Of An Application For Database Maintenance In Inventory Management System Using Tkinter And Sqlite Platform
Authors: Yuvaraj K , Oorappan G M , Megavarthini K K , Pravin M C , Adharsh R , Ashwath Kumaran M
Published: December 2020

The challenges in classical way of inventory log are human mathematical ability, paper maintenance, untidy process of editing and chances of missing the data of invoice and outward. The proposed idea is to develop an inventory management application using Tkinter and SQLite platform that creates a way towards progressively from traditional applications to a fully connected and customized inventory management system. This application uses password encryption to ensure the data privacy between the administrators and other workers of the industry. The system utilizes the integration of Tkinter and SQLite for the effective Graphical User Interface interfaced with Relational Database Management System. This customized application enables the administrator to add a new employee or remove the existing employee, he can update the stock quantity, and can back up the invoice history. Due to the login feature, the details of the product outward such as who withdrew and when it was withdrawn are automatically stored in the database. This digitization of inventory management system increases flexibility, reliability, smart storage, resource utilization, easy access to product location and warehouse management. It would be one time investment no further investment needed if at all any problem or errors occur in the app by human mishandling. The application saves us a lot of time because it uses SQL in it which is structured language, the data can be retrieved soon without any time delay and the human errors are avoided due to its structured nature.
Automation and performance analysis of tea filter bags packing process using delta configured robot
Authors: Vigneshwaran S , Nagarajan P , Mohamed Ismail A , Yuvaraj K
Published: December 2020

A delta robot is a type of parallel robot that consists of three arms connected to universal joints at the base. Industries take advantage of these robots in packaging and pick and place operations due to its high accuracy and fastness. This three degrees of freedom robot is used in the process that automates the tea filter bags packing process through pick and place operation. Electrostatic gripper has been used as the end effectors. The tea filter bags are allowed to go through the conveyor and this delta configured robot is used for pick and place operation. This robot reduces the time complexity of the laborers and it also helps in increasing productivity by reducing the cost. Thus the tedious process becomes simpler through the delta configuration. Comparative analysis of the performance of robot with manual process is also shown in the results.
Control and Stabilization of Pitch Axis Angle In 3 DOF Titltrotor
Authors: Dhanasekar R. , Kalaiyarasi M. , Arunjayakar S. , Raghunath M. , prabhu S. Raghavendra
Published: December 2020

Tiltrotor system is used in army for security purpose and mission attack. This system is affect due to environment conditions such as wind flow, rain and low atmospheric pressure, the system becomes unbalanced in working conditions. In recent days new control technique called fractional order PID have a conspicuous growth in the field of controller design for controlling the various linear and nonlinear system applications. The fractional order PID controller used in tiltrotor model, improves the system performance compared with other controllers. The proposed work deals with the Pitch axis control of tiltrotor system using FOPID controller and also performance has been compared with PID controller, with different tuning methods. The FOPID controller provide more flexibility in designing a controller than using PID controller due to selection of tuning parameters. FOPID and PID controller has been designed for pitch axis control, the performance characteristics of the system has been compared and analyzed by using MATLAB simulation.
Performance Evaluation of Portable Mist Humidifier
Authors: Mahesh M. , Thangavel P. , Bhuvaneshwaran K. , Boopathi Raja V. , Dinaesh Krishna S.
Published: December 2020

This paper deals with the performance evaluvation of portable mist humidifier, for producing a cooling effect in a specified area. A humidifier is an electrical device that increases the humidity of an environment. So the room temperature got reduced with the help of increasing the humidity. This devise provides a cooling effect at low cost without health hazards. The experimental arrangement made with the components of axial fan, copper tubes, hydraulic pump, nozzles, respectively. The misting nozzles are placed into the holes which are made in the copper tube and the copper tube is fitted over the frame on the axial fan. The hydraulic pump is kept in the water tank to circulate the water to the copper tube. When the water flows through the tube it emits water droplets with the help of misting nozzles. Due to the high-speed axial fan, the emitted water droplets are sprayed into the atmosphere as a mist. When there is a increase in the moisture content there will be decrease in room temperature. Due to this effect the room temperature has been decreased by 12% with the help of humidifier.
Performance analysis on Solar Air Heater with Discrete Arc Shaped Rib Element in Absorber Plate
Authors: Makeshkumar M. , Thangavel P.
Published: December 2020

Solar Air Heater (SAH) absorbs the irradiation and converts it into thermal energy, which is supplied to flowing fluid for the purpose of drying agricultural products, curing of industrial products, space heating applications and so on. An experimental examination has been conducted to assess the thermal performance of SAH having discrete arc shaped rib element in the absorber plate and analyzed against Flat Plate Solar Air Heater (FPSAH). Performance has been assessed by identifying the various parameters like useful heat gain, surface temperatures of collector plate, flow rate of working fluid, temperatures of air at inlet and exit. Investigation has been performed for flow rates of 0.028 kg/s and 0.045 kg/s. The results indicate that the absorber plate with artificial roughness element shows considerable increase in exit air temperature, heat transfer rate and thermal efficiency. Thermal efficiency of about 70 % is obtained for 0.045 kg/s, which is 13.1% more than that of FPSAH.
Dynamic Clustering-Genetic Secure Energy Awareness Routing To Improve the Performance of Energy Efficient In IoT Cloud
Authors: Karthika E , Mohanapriya S
Published: December 2020

The Internet of Things (IoT) is one of the emerging technologies that has attracted the attention of researchers in the field of education and industry. The idea behind the Internet of Things is that things and devices are operated on the Internet to achieve some common goals with humans. It serves as a platform for monitoring the collection process, controlling the cyber-global fire world, and collecting data and analyzing data using IoT sensor nodes. Power saving is important for battery-powered devices. The amount of previous work is small, although it has a large tip capacity, especially in terms of battery life and energy efficiency. This regulates the development of IoT a simple and energy efficient routing scheme for war sensor networks. The nodes require an increased lifespan of intelligently transmitted data communications. To conserve the energy of IoT nodes, the Dynamic Clustering-Genetic Secure Energy Awareness Routing Protocol (DC-GSEARP) utilizes clustering, cluster head selection and energy and efficient path calculation for efficient and real-time routing. To accomplish the efficient cluster head selection, to have used Dynamic Clustering algorithm. The proposed DC-GSEARP protocol achieve an improved that can be used to construct an optimal path for energy efficient data transmission for IoT sensor nodes. DC-GSEARP, which uses the integration of clustering supported by short path resolution to provide energy efficient and advanced routing capabilities for IoT, ensures entering a path with lower power consumption and enhanced QoS measurements. The results of the simulations show that the proposed approach can reduce the power consumption of sensor nodes, data packet losses and extend network life.
On the fabrication and mechanical modelling microscale bistable tensegrity systems
Authors: Vangelatos Z , Farina I , Micheletti A , Singh N , Grigoropoulos C P , Fraternali F
Published: December 2020

We report about the analysis, design, and experimental testing of modular structures composed of bistable units derived from the classic triangular tensegrity prism. Tensegrity structures are pin-connected frameworks, composed by bars and cables, possessing internal mechanisms and self-stress states, and featuring a variety of structural responses depending on their prestress, edge connectivity, and geometry. When a tensegrity system has only one internal mechanism and one self-stress state, as in the triangular prism case, it is possible to associate to it a corresponding bistable unit, by replacing all cables with bars and changing their edge-lengths slightly. After presenting experimental results of compression tests carried out on microscale specimens fabricated through multiphoton lithography, we compare them with the numerical predictions obtained by our computational model.
Mechanics of energy harvesters based on tensegrity solar facades
Authors: Miranda R , Babilio E , Singh N , Villamil D P , Santos F , Fraternali F
Published: December 2020

This work is focused on the computational design of tensegrity shading systems of energy efficient buildings which mitigate air conditioning consumption and optimize the energy performance of the building. It is concerned with the design of active solar façade screens based on lightweight tensegrity units, which are easily integrated with energy harvesting piezoelectric cables. The unit cells of the analyzed screens are controlled by tensioning and releasing selected cables of the structure and are used to direct the shading panels towards the sun. A numerical procedure simulates the dynamics of the analyzed tensegrity façades, by considering the opening and closure motions of the screens, and the vibrations produced by the action of dynamic wind forces. The energy harvesting ability of the proposed façade is numerically estimated.
Formation of Discontinuities in Rectangular Plates as a Result of Residual Stress Relief
Authors: Menshova I V , Kerzhaev A P , Yu G , Zeng X
Published: December 2020

The paper deals with the problem of relieving residual stresses in an elastic domain of rectangular shape with free sides as a result of the formation of a discontinuity of particular shape. First, we construct the solution to the problem of residual stresses in an infinite strip with free sides and with a central transverse cut on which a discontinuity of displacements is known. Then, the solution for a rectangle is added to this solution, with the help of which the boundary conditions at the ends are satisfied. The formulas for the residual stresses and for the corresponding displacements are represented in the form of series in Papkovich-Fadle eigenfunctions. The expansion coefficients (Lagrange coefficients) have the form of simple Fourier integrals.
Lubrication performance analysis of the connecting rod bearing based on AVL EXCITE
Authors: Zhong Ning , Wu Bo , Zhang Le , Xin Qi , Tu Liyue , Li Hulin
Published: December 2020

The lubrication state of connecting rod bearing has influence on the reliability and lifetime. It is necessary to analyze the lubrication state of connecting rod bearing to evaluate and design the lubrication performance. The connecting rod bearing hydrodynamic lubrication simulation model was set up for 9XX diesel engine and journal bearing fatigue test-rig at Glacier Vandervall. The effect of maximum oil film pressure, minimum oil film thickness and maximum asperity contact pressure on the lubrication performance were studied. Then the lubrication states of connecting rod bearings under different working conditions were discussed based on two test machines. The results are of great significance for analyzing the lubrication performance of connecting rod bearings and the reliability of bearings.
Seismic performance and fragility functions of confined masonry old infrastructure with handmade bricks
Authors: Gonzales G H , Aguilar A G , Huaco G , Garber D
Published: December 2020

In several countries, confined masonry structures with handmade bricks were built for common to essential infrastructure. These bricks were made by clay using artisanal ovens; therefore, they have mechanical properties less than seismic codes currently recommend. Many of these buildings are one to three stories and were designed following past design codes or were built without considering any design codes. There is an uncertainty of the strength or ductility for these buildings to resist a severe earthquake event. For this purpose, this study aimed to develop fragility functions as way to estimate and quantify the vulnerability of these structures. This research describes a methodology to find fragility functions based on a nonlinear model with three levels of masonry handmade bricks. Experimental test data was used to validate the proposed model during the calibration process. Incremental dynamic analyses were developed for 11 pairs of seismic records for both orthogonal directions. Fragility functions reported a high probability of collapse for demand levels from a design earthquake to maximum capable earthquake.
Automatic Surface Defect Inspection System Using Convolutional Neural Networks
Authors: Zhu X , Kundu S K , Bangalore Ramaiah N K
Published: December 2020

Surface quality of the piston rod is very important for the durability of the shock absorbers. However, currently in production, it is very difficult to use the available systems to inspect the whole rod surface online, in real time (∼4s), with a high sensitivity and accuracy. To overcome this, in this paper, an online automatic rod inspection system has been developed, which allows to inspect the whole rod surface in 4s, with a sizing accuracy around 75%, and detection accuracy <90%. An integrated software is used for rod rotation control, image capturing, image processing, and decision making. Convolutional Neural Network is used to processing the 360° surface image with a high accuracy, eliminating errors caused by environmental lighting. A new method based on aspect ratio and size information is used for defects classification. Experimental results show that the system is capable of detecting defects as small as 25μm and differentiating nodule, dent, and scratch with a processing time around 4s per rod.
Buckling of micropolar beams by an improved first order deformation theory
Authors: Betancourt K N , Soncco K , Arciniega R
Published: December 2020

In this paper, we present a variational formulation to study the buckling behavior of micropolar beams by using an improved 3D deformation theory. A micropolar continuum applied to beams has been developed using its natural Lagrangian kinematic relations. The Rodriguez rotation measure was used to describe the rotational degrees of freedom. Additionally, a Taylor expansion was performed to linearize the kinematic relations. For the buckling analysis, the Trefftz criterion procedure was applied. A finite element model was derived for the solution of the variational problem using spectral interpolation functions for a higher convergence rate and for avoiding shear locking problems. The results describe the influence of the micropolar parameters and size-dependent behavior. Finally, the model was used to evaluate the buckling loads of simply-supported functionally graded beams considering experimental material parameters.
Comparative genomics of cetartiodactyla: energy metabolism underpins the transition to an aquatic lifestyle
Authors: Derous Davina , Sahu Jagajjit , Douglas Alex , Lusseau David , Wenzel Marius
Published: December 2020

Foraging disruption caused by human activities is emerging as a key issue in cetacean conservation because it can affect nutrient levels and the amount of energy available to individuals to invest into reproduction. Our ability to predict how anthropogenic stressors affect these ecological processes and ultimately population trajectory depends crucially on our understanding of the complex physiological mechanisms that detect nutrient availability and regulate energy metabolism, foraging behavior and life-history decisions. These physiological mechanisms are likely to differ considerably from terrestrial mammalian model systems. Here, we examine nucleotide substitution rates in cetacean and other artiodactyl genomes to identify signatures of selection in genes associated with nutrient sensing pathways. We also estimated the likely physiological consequences of adaptive amino acid substitutions for pathway functions. Our results highlight that genes involved in the insulin, mTOR and NF-ĸB pathways are subject to significant positive selection in cetaceans compared to terrestrial artiodactyla. These genes may have been positively selected to enable cetaceans to adapt to a glucose-poor diet, to overcome deleterious effects caused by hypoxia during diving (e.g. oxidative stress and inflammation) and to modify fat-depot signaling functions in a manner different to terrestrial mammals. We thus show that adaptation in cetaceans to an aquatic lifestyle significantly affected functions in nutrient sensing pathways. The use of fat stores as a condition index in cetaceans may be confounded by the multiple and critical roles fat has in regulating cetacean metabolism, foraging behavior and diving physiology.
Context-dependent variability in the predicted daily energetic costs of disturbance for blue whales
Authors: Pirotta Enrico , Booth Cormac G , Cade David E , Calambokidis John , Costa Daniel P , Fahlbusch James A , Friedlaender Ari S , Goldbogen Jeremy A , Harwood John , Hazen Elliott L , New Leslie , Southall Brandon L
Published: December 2020

Assessing the long-term consequences of sub-lethal anthropogenic disturbance on wildlife populations requires integrating data on fine-scale individual behavior and physiology into spatially and temporally broader, population-level inference. A typical behavioral response to disturbance is the cessation of foraging, which can be translated into a common metric of energetic cost. However, this necessitates detailed empirical information on baseline movements, activity budgets, feeding rates and energy intake, as well as the probability of an individual responding to the disturbance-inducing stressor within different exposure contexts. Here, we integrated data from blue whales (Balaenoptera musculus) experimentally exposed to military active sonar signals with fine-scale measurements of baseline behavior over multiple days or weeks obtained from accelerometry loggers, telemetry tracking and prey sampling. Specifically, we developed daily simulations of movement, feeding behavior and exposure to localized sonar events of increasing duration and intensity and predicted the effects of this disturbance source on the daily energy intake of an individual. Activity budgets and movements were highly variable in space and time and among individuals, resulting in large variability in predicted energetic intake and costs. In half of our simulations, an individual’s energy intake was unaffected by the simulated source. However, some individuals lost their entire daily energy intake under brief or weak exposure scenarios. Given this large variation, population-level models will have to assess the consequences of the entire distribution of energetic costs, rather than only consider single summary statistics. The shape of the exposure-response functions also strongly influenced predictions, reinforcing the need for contextually explicit experiments and improved mechanistic understanding of the processes driving behavioral and physiological responses to disturbance. This study presents a robust approach for integrating different types of empirical information to assess the effects of disturbance at spatio-temporal and ecological scales that are relevant to management and conservation.
Innovations and paradigm shifts in atrial fibrillation ablation
Authors: Mulder Bart A , Luermans Justin G L M , Hindricks Gerhard , Blaauw Yuri
Published: December 2020

Treatment of symptomatic atrial fibrillation has seen important changes in the past decades. Advancements have especially been made in the field of non-pharmacological treatment of this disease. Patients in whom a rhythm control strategy is chosen the place of catheter ablation has become more frontline therapy in the past years. The procedure itself has also seen changes in technologies that can be used, either using point-by-point radiofrequency or one of the single-shot techniques. One of the major limitations that remain is that re-do procedures are often necessary due to incomplete pulmonary vein isolation and/or atrial fibrillation being initiated by other mechanisms than pulmonary vein triggers. Therefore, there is further need for developing ablation tools that reproducibly isolate the pulmonary vein transmurally. Furthermore, addressing the underlying conditions before and after catheter ablation has been shown to be of great importance. In this review, we will give an overview of the evolution of catheter ablation, highlight the latest technologies and their future endeavours, and lifestyle modifications are being discussed as part of the catheter ablation strategy.
Epstein–Barr virus infection modulates blood–brain barrier cells and its co-infection with Plasmodium falciparum induces RBC adhesion
Authors: Indari Omkar , Chandramohanadas Rajesh , Jha Hem Chandra
Published: December 2020

Plasmodium falciparum infection-mediated Epstein–Barr virus (EBV) reactivation is well established in malaria-endemic countries. We hypothesize that, during malaria onset, the reactivated EBV can infect human brain microvascular endothelial cells (HBECs). This may cause severe cerebral manifestations. We infected HBECs with EBV in vitro. The subsequent gene expression pattern of EBV, inflammatory and endothelial markers was analysed using qRT-PCR. Further, a wound-healing assay for cells maintaining blood–brain barrier (BBB) integrity was performed to investigate the effect of EBV-infected HBECs secretions. The RBC adhesion assay was conducted to assess RBC attachment onto HBECs during EBV and P. falciparum mono- and co-infection. Our experiments revealed that EBV infection of HBECs significantly elevated several inflammatory (TNFα, CCL2) and endothelial (integrin β3, PECAM, VEGFA, VWF, claudin-5, cx37) markers. The EBV-infected HBECs secretion significantly reduced migration of HBECs, glial and neuronal cells. Additionally, EBV–P. falciparum co-infection significantly (P < 0.05) enhanced RBC adhesion to HBECs compared to mono-infection scenarios. Conclusively, the EBV infection of HBECs led to endothelial activation and modulated the BBB microenvironment. The EBV-P. falciparum co-infection scenario increased RBC adhesion on ECs which is a hallmark of cerebral malaria. Together with malaria, EBV infection can aid in exacerbation of cerebral malaria pathology.
Comparison of long-read methods for sequencing and assembly of a plant genome
Authors: Murigneux Valentine , Rai Subash Kumar , Furtado Agnelo , Bruxner Timothy J C , Tian Wei , Harliwong Ivon , Wei Hanmin , Yang Bicheng , Ye Qianyu , Anderson Ellis , Mao Qing , Drmanac Radoje , Wang Ou , Peters Brock A , Xu Mengyang , Wu Pei , Topp Bruce , Coin Lachlan J M , Henry Robert J
Published: December 2020

Background

Sequencing technologies have advanced to the point where it is possible to generate high-accuracy, haplotype-resolved, chromosome-scale assemblies. Several long-read sequencing technologies are available, and a growing number of algorithms have been developed to assemble the reads generated by those technologies. When starting a new genome project, it is therefore challenging to select the most cost-effective sequencing technology, as well as the most appropriate software for assembly and polishing. It is thus important to benchmark different approaches applied to the same sample.

Results

Here, we report a comparison of 3 long-read sequencing technologies applied to the de novo assembly of a plant genome, Macadamia jansenii. We have generated sequencing data using Pacific Biosciences (Sequel I), Oxford Nanopore Technologies (PromethION), and BGI (single-tube Long Fragment Read) technologies for the same sample. Several assemblers were benchmarked in the assembly of Pacific Biosciences and Nanopore reads. Results obtained from combining long-read technologies or short-read and long-read technologies are also presented. The assemblies were compared for contiguity, base accuracy, and completeness, as well as sequencing costs and DNA material requirements.

Conclusions

The 3 long-read technologies produced highly contiguous and complete genome assemblies of M. jansenii. At the time of sequencing, the cost associated with each method was significantly different, but continuous improvements in technologies have resulted in greater accuracy, increased throughput, and reduced costs. We propose updating this comparison regularly with reports on significant iterations of the sequencing technologies.