bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Single Walled Tank Under Cryogenic Conditions Made of Composite
Authors: Kutz Philipp W. , Otremba Frank , Werner Jan , Sklorz Christian 
Published: January 2019

The use of glass-fiber reinforced plastic (GRP) can reduce the weight of tanks significantly. By replacing steel with GRP in tanks for gases (propane, etc.) a weight reduction of up to 50 % was reached. In this project not only the material should be optimized, but also the design. Previous tanks consist of a double-walled structure with an insulation layer between the two shells (e.g. vacuum). Goal of this project is to realize a single-walled construction of GRP with an insulation layer on the outside.
To determine the temperature dependent material values, two different experiments are performed: In the first experiment, temperature dependent material properties of liquid nitrogen found in literature research are validated in a simple setup. The level of liquid nitrogen in a small jar is measured over the experiment time. Numerical simulation shows the change of nitrogen level with sufficient precision. In the second experiment, a liquid nitrogen is applied on one side of a GRP plate. Temperature is measured with thermocouples on top and bottom of the GRP plate, as well as in the middle of the plate. By use of numerical simulation, temperature dependent thermal conductivity is determined.
In the third experiment, a test stand is designed to examine different insulation materials. In this test stand, the insulation material can easily be changed. A numerical simulation, in which the determined material data is used, is performed as well for this test stand.
The experiments show, that GRP can be used in cryogenic environments. Multiphase simulations are a suitable tool to describe the energy absorption of thermal energy due to thermal phase change. Results on different insulation materials will follow.
Energy Demand, Efficiency Measures and Embodied Energy in the Italian Residential Sector
Authors: Abd Alla Sara , Bianco Vincenzo , Scarpa Federico , Tagliafico Luca A. 
Published: January 2019

This paper investigates a strategy for energy saving in the Italian residential sector that includes in the assessment the embodied energy related to the efficiency measures. Simulations are run in three main cities (Milan, Rome and Naples) covering different climate zones. The purpose is, firstly, to estimate the baseline of the buildings energy consumption, secondly, to simulate the implementation of realistic retrofit solutions and, finally, to assess the retrofitting’ embodied energy and its energy payback time.
The energy payback is based on the comparison between the net saved operational site energy and the embodied energy of the selected measures.
By running the simulations, it is possible to estimate the maximum potential for energy savings and realistic estimation of achievable results in short-medium period.
Results show the energy efficiency measures more convenient in terms of energy payback depending on the climate zone.
For Naples, a focus on façade insulation has been held and the results defined the optimal material thickness in terms of embodied energy and net saved operational site energy in a life cycle of 15 years.
Dielectrophoretic Control of a Droplet at the Interface of Two Liquids in a Three Liquid System
Authors: Lokanathan Manoj , Wikramanayake Enakshi , Bahadur Vaibhav , Bonnecaze Roger 
Published: January 2019

The influence of an electric field on a water droplet resting at the interface of two immiscible liquids is studied experimentally and theoretically. The droplet is initially in a state of equilibrium due to the balance between gravitational, buoyancy and capillary forces. Application of an electric field across the droplet-interface system disturbs the equilibrium. The electrical force increases the immersion angle of the droplet and eventually causes it to ‘sink’ when a critical immersion angle is reached.
Experiments are conducted with a deionized water droplet, resting at the interface of silicone oil and sunflower oil. Experiments involve the application of an electric field and image analysis to track the voltage dependent immersion angle. The objective is to determine the threshold voltage at which the droplet sinks. Experiments are complemented by an analytical model that balances gravity, buoyancy, capillary, and dielectrophoretic forces to predict the change in the position of the droplet and the immersion angle. Experiments and analysis were conducted for Bond numbers ranging from 0.1 to 1.7, the latter being the critical size at which a droplet will ‘sink’ due to its weight. The predicted immersion angles and threshold voltage show a good match to the experimental measurements. Overall, this work highlights the utility of electric fields to control interfacial phenomena at the interface of two immiscible liquids.
Immersive Educational Systems With Procedure-Oriented Combinations of Real and Virtual Environments
Authors: Zhang Zhou , Zhang Shaojin , Zhang Mingshao , Esche Sven K. 
Published: January 2019

Virtual reality (VR) is becoming increasingly popular in educational applications, but insufficient users’ feel of immersion often slows the further adoption of VR. Many solutions with a focus on the results rather than the details of the interactions between the objects in the real and virtual worlds have been developed. Therefore, the real procedures are distorted and the users lose their perception of in-person participation.
In order to improve the users’ feel of immersion further and to simulate more realistic operations in VR, a procedure-oriented approach for the combination of real and virtual environments is proposed here. As its name implies, this approach emphasizes the details of the procedures, namely how to capture, track, operate and interoperate the real and virtual objects in a mixed environment. In order to illustrate this idea, a prototype of mixed real and virtual assembly, in con-junction with object recognition and rigid-object tracking functions based on robotic vision techniques, is presented as an example. This prototype is designed based on a game-based virtual laoratory system, and the specific implementation is a planetary gear train experiment. In this experiment, all models of the parts with the information required for the assembly are created, labeled and added to the database of the virtual laboratory system. The physical parts are marked in order to facilitate object recognition and object tracking. During the experiment, the main assembly with one missing planetary gear is accomplished in a purely virtual environment. In the real world, the missing planetary gear is tracked by a Kinect while the user is manipulating this gear. Then, the system recognizes this gear based on the markers and couples the corresponding virtual model of that gear with the avatar’s hand in the virtual environment. Afterward, the cam-era tracks the real part, and the user can adjust its pose and location to finish the final assembly. The main benefit of this implementation is that the user can take advantage of some simple real parts in conjunction with virtual models of sophisticated parts in order to get realistic experience with the assembly process.
An Accurate On-Line Correction Strategy for Gravity Compensation Aiming at Teaching by Touch of Collaborative Robots
Authors: Dong Yunfei , Ren Tianyu , Wu Dan , Chen Ken 
Published: January 2019

Modern industrial robots are increasing rapidly towards collaborating and physically interacting with people on complex tasks, and away from working in isolated cages that are separated from people. Collaborative robots are usually developed to perform variable stiffness control, teaching by touch, collision detection, and so on. Torque control with accurate gravity compensation becomes necessary.
When the method of torque-based impedance force-control is used to achieve teaching by touch, the gravity compensation is added to the joint torque loop directly. As a result, the gravity model should be very accurate, otherwise the robot will not stay still even if no any artificial external force is applied. Unfortunately, it is very difficult to model and identify the robot dynamics such accurately in the whole working space because of the presence of the robot cables, joint and link flexibility, cables or tube of end-effector, the end-effector itself and so on. There are always some regions where the robot will drift due to the error of gravity compensation.
This paper is motivated by the gravity compensation problem of collaborative robots equipped with joint torque sensors, and attempts to propose an accurate on-line correction strategy for gravity compensation especially aiming at the application of teaching by touch. The developed method has been tested on a 7-DOF collaborative robot and shown good performance.
Development of Soft Body Rescue-Bot Using 3D Printing
Authors: Lewis Cody , Legg Jared , Shin Minchul 
Published: January 2019

The use of robots in search and rescue operations has increased dramatically over the years. A robot is able to detect survivors of a dangerous situation, like an earthquake, without putting the operator’s life in danger as well. There are many types of robots being developed for search and rescue purposes, but a smaller and more durable robot will be beneficial for designs in the future.
The purpose of our project is to research and design a soft body robot that is capable of locating individuals in search and rescue operations. The robot has a design similar to a car which will allow the control of the robot to be easy to use. It has been designed with a self-righting mechanism in case the vehicle flips over or gets stuck. The robot has a small size so that it can fit through small holes that a person could not enter. The robot will be capable of traversing over uneven terrain, including small ledges through an actuator. The actuator will be designed to cause the robot to spring over or on a ledge. According to simulations from SolidWorks, the wheels of the robot can also withstand a drop from 2 meters. The design and material of the wheels will be further tested and changed to increase the performance of the wheel. Once a design has been chosen, the body of the robot will be designed. Current designs of ground rescue robots will be studied in order to attain a better understanding on what designs work best. The hope is to make the robot more durable than previous designs using a soft material as the outer shell of the robot. A soft material should allow the robot to be able to absorb impacts from falling debris or unexpected falls.
Once the design of the robot has been optimized, a prototype will be created. The next step will be to code the robot so that it can be controlled with a remote. The current proposal is to use an Arduino board to send and receive signals from that remote. Then a camera will be attached to the robot which will allow the operator to see where the robot is and where the survivors are located.
Improving the Heat Dissipation From a Pressure Wheel of a Laser Robotic End-of-Arm Tooling Using Different Geometrical Designs and Materials
Authors: Hamieh Abdallah , Kheirallah Mike A. , Jawad Badih , Liu Liping , Fernandez Vernon 
Published: January 2019

The automotive industry corporations noticed the advantages of automated laser welding. Robot laser welding systems have immediately attracted their interests for bringing down the production costs and delivering higher-quality items. The objective of this research is to study how to enhance heat dissipation to endorse a better performance of the pressure wheel, and help achieve a longer life cycle. Transient thermal analysis of the pressure wheel was conducted using ANSYS workbench. The work studied the effects of different design models and materials on the thermal performance of pressure wheel assembly during the cooling period. Numerical simulations were performed on both solid and geometrically ventilated wheels for enhancing the heat dissipation performance of the wheel. Different materials were also be tested and compared. The analysis will support the design process by monitoring different parameters in terms of performance, heat loss and manufacturing cost.
A comparison was made for two different designs each with three different materials and the best design was selected. The simulation results in a period of 50 seconds cooling time showed that the temperature dropped with the 1st design (full solid wheel) made of tungsten from an initial temperature Ti = 500 K to a final temperature of Tf = 434.5 K. Tungsten was found to have better heat dissipation compared to stainless steel and cast iron. For the 2nd design (geometrically ventilated wheel) made of tungsten, the temperature drops from Ti = 500 K to Tf = 422.1 K. Comparing the two designs, the geometrically ventilated wheel was proved to be cooled faster. The present work will help improve the performance of pressure wheel in the welding industry by providing computational results for successive design testing and data validation.
A Comparative Study of Rapid Quadrupedal Sprinting and Turning Dynamics on Different Terrains and Conditions: Racing Greyhounds Galloping Dynamics
Authors: Hayati Hasti , Walker Paul , Mahdavi Fatemeh , Stephenson Robert , Brown Terry , Eager David 
Published: January 2019

Identifying optimum athletic race track surfacing for greyhounds to reduce risk of injuries is a challenging practice as there are several single and coupled variables that should be considered as risk factors. To study the impact of bend and straight sections, surface type and camber, on biomechanics of galloping quadrupeds, an inertial measurement unit (IMU).
has been used to measure the associated galloping accelerations. The IMU was sewn into a pocket located on the back of the greyhounds racing jacket positioned between the two forelegs. Simultaneous kinematics were performed using high frame rate (HFR) videos for calibrating IMU data. The results showed that there were lower G-forces on galloping on grass than wet sand which is consistent with the mechanical behavior of grass (grass is softer than wet sand). Moreover, galloping around the bend had higher G-forces than galloping along the straight section suggesting an excessive force is applied on the greyhound’s limbs due to centrifugal force. A cambered bend assisted the greyhounds in having a smoother gait and lower G-forces when compared to a flat bend. The results reported in this paper will not only be beneficial for the welfare of racing greyhounds, but will also contribute in the simulation of legged locomotion for bio-inspired engineering and robotics.
Experimental Analysis and Testing of the Hemming Process Types Utilized in the Automotive Industry
Authors: Limon-Leyva Pablo Alberto , García-Zugasti Pedro de Jesús , Balvantín-García Antonio de J. , de la Peña José A. Diosdado , Sanchez-Arce Isidro de Jesus , Govea-Valladares Eder Hazael 
Published: January 2019

A comparative experimental analysis of three common hemming processes used in the automotive industry is presented. These processes are die hemming, table hemming, and roll hemming. We aim to determine which one of the three processes provides the better quality hemming.
The die hemming and table hemming used in this study were performed with custom made tooling and a 35 tonne hydraulic press. Similarly, roll hemming was performed using a custom made workbench with a three-degree of freedom system of rolls.
The material used for testing was aluminum sheet (6011); three rolling directions were taken in account: 0°, 45°, and 90° for the manufacture of the samples.
Hemming quality was determined from the geometric variables such as: lip high, pre-hemming angle, tool position, roll radius (roll hemming only). As a result, the comparison of roll in/out and wrinkle defects are reported and compared.
Novel Approach for Tension Testing Micro Tubes
Authors: Wagner Scott W. , Emblom William J. , Johnson Kevin M. , Shah Kahaan P. , Handa Navrose , Kapare Nihal 
Published: January 2019

Due to the miniaturization of products, new or modified processes are required to create small components. With the development of these new processes, it is also important to establish methods to evaluate the mechanical properties of the materials used in these components. These properties are necessary for accurately creating representative predictive models and simulations. At the same time, this evaluation can be challenging as sampling specimens become smaller the securing and handling of these smaller specimens becomes very difficult.
Recently, researchers made studies to develop and model the micro tube hydroforming (MTHF) process. In many of these studies, the mechanical properties used were either traditional book values or were values obtained directly from the manufacturers. The question then becomes, how do the manufacturers determine their provided mechanical properties?
The research in this study focuses on the development and testing of a new process to determine the mechanical properties of stainless steel micro tubes. Specifically, a set of clamps for securing a micro tube in a standard tension-testing machine were developed. A method for localizing the stress within the middle of a specimen was developed and the findings are presented in this paper.
Degradation of the Strength of a Grain and a Grain Boundary due to the Accumulation of the Structural Defects of Crystal
Authors: Zheng Guoxiong , Luo Yifan , Miura Hideo 
Published: January 2019

Various brittle fractures have been found to occur at grain boundaries in polycrystalline materials. In thin film interconnections used for semiconductor devices, open failures caused by electro- and strain-induced migrations have been found to be dominated by porous random grain boundaries that consist of a lot of defects. Therefore, it is very important to explicate the dominant factors of the strength of a grain boundary in polycrystalline materials for assuring the safe and reliable operation of various products.
In this study, both electron back-scatter diffraction (EBSD) analysis and a micro tensile test in a scanning electron microscope was applied to copper thin film which is used for interconnection of semiconductor devices in order to clarify the relationship between the strength and the crystallinity of a grain and a grain boundary quantitatively. Image quality (IQ) value obtained from the EBSD analysis, which indicates the average sharpness of the diffraction pattern (Kikuchi pattern) was applied to the crystallinity analysis. This IQ value indicates the total density of defects such as vacancies, dislocations, impurities, and local strain, in other words, the order of atom arrangement in the observed area in nano-scale. In the micro tensile test system, stress-strain curves of a single crystal specimen and a bicrystal specimen was measured quantitatively. Both transgranular and intergranular fracture modes were observed in the tested specimens with different IQ values.
Based to the results of these experiments, it was found that there is the critical IQ value at which the fracture mode of the bicrystal specimen changes from brittle intergranular fracture at a grain boundary to ductile transgranular fracture in a grain. The strength of a grain boundary increases monotonically with IQ value because of the increase in the total number of rigid atomic bonding. On the other hand, the strength of a grain decreases monotonically with the increase of IQ value because the increase in the order of atom arrangement accelerates the movement of dislocations. Finally, it was clarified that the strength of a grain boundary and a grain changes drastically as a strong function of their crystallinity.
Development of a Flexible Tactile Sensor Using Area-Arrayed Bundle Structures of Multi-Walled Carbon Nanotubes
Authors: Osada Ryusaku , Suzuki Ken 
Published: January 2019

In recent years, surgical assisting robots and nursing care robots are being introduced to medical and nursing fields due to the rapid increase of the aging society. In order to assure the safety and reliability of these robots, a highly sensitive tactile sensor is necessary to detect the state of contact between these robots and human body. The target specifications of this sensor are spatial resolution of less than 1 mm, and the pressure sensitivity of less than 10 kPa. Since the tactile sensor is expected to be attached on the tip of a surgical assisting robot or the arm of a nursing care robot, it should be small and flexible and highly sensitive to contact pressure.
In this study, high quality MWCNT (Multi-Wall Carbon Nanotube) has been synthesized to develop two types of tactile sensors which consisted of a MWCNT film and the area-arrayed MWCNT bundles. Thermal CVD (Chemical Vapor Deposition) method was applied to the growth of MWCNT and PDMS (Polydimethylsiloxane) was used for a flexible substrate. It was found that MWCNT bundles showed elastic deformation in the compressive strain range from 0% to 60%. The PDMS substrate showed elastic deformation under the application of bending strain of about 20%. In addition, it was confirmed that the detecting resolution of the force was lower than 1 mN, and the obtained gauge factor of the developed sensor was about 3.5.
Crystallinity-Induced Variation of the Electronic Characteristics of Electroplated Gold Thin Films
Authors: Nakoshi Yutaro , Miura Hideo 
Published: January 2019

Electroplated gold thin films have been used for micro bumps in flip chip packing structures. However, it has been reported that physical properties and micro texture of the electroplated thin films vary drastically comparing with those of conventional bulk material, depending on their electroplating process. In addition, since one bump is going to consist of a few grains or a single grain due to the miniaturization of the 3D structures, it shows strong anisotropic mechanical properties because a face-centered cubic crystal essentially has strong anisotropy of physical properties. Therefore, there should be the wide distribution of characteristics of the micro bumps depending on their micro structure and the variation of the crystallinity of grains and grain boundaries enlarges the width of the distributions of various properties. Particularly, it was found that the long-term reliability of micro bumps and interconnections is degraded drastically by porous grain boundaries with a lot of defects because of the acceleration of atomic diffusion along the porous grain boundaries under the application of high current density (electromigration) and high mechanical stress (stress-induced migration).
In this study, the effect of crystallinity, in other words, the order of atom arrangement of grain boundaries in electroplated gold thin films on the EM resistance was investigated experimentally. The crystallinity of the gold thin films was varied drastically by changing the under-layer material used for electroplating; such as Cr (30 nm) / Pt (50 nm)/ Au (200 nm) and Ti (50 nm) / Au (100 nm). The mechanical properties of the electroplated gold thin films were measured by using a nano-indentation test. Also, the micro textures such as crystallinity and crystallographic orientation of gold thin films were investigated by EBSD (Electron Back-Scatter Diffraction) and XRD (X-Ray Diffraction). It was clarified that the crystallinity of the electroplated gold thin films changed drastically depending on the crystallinity of the under-layer materials and heat treatment conditions after electroplating. This variation of the crystallinity should have caused the wide variation of mechanical properties of the electroplated gold films. Therefore, it is very important to control the crystallinity of the under layer used for electroplating in order to control the mechanical properties and reliability of the electroplated gold thin films.