bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Boundary Layer on the End Wall of a Turbine Nozzle Cascade
Authors: Senoo Yasutoshi 
Published: January 2022

Abstract
The boundary layer flow was experimentally studied on an end wall of a turbine-nozzle cascade and the following results were obtained. 1 The boundary layer was laminar at the throat of the nozzle, even when the upstream boundary layer was apparently turbulent. 2 The end-wall boundary layer in the nozzle was little affected by the upstream boundary layer. A theoretical consideration supports the results and also reveals that the part of secondary flow in the nozzle, which is related to the upstream boundary layer, depends upon the configuration of the nozzle. 3 The observed boundary layer behavior was compared with the predicted flow by a three-dimensional laminar boundary layer theory, and good agreement was obtained. 4 The measurements showed the end-wall boundary layer rolling up at the suction-surface end-wall corner of the cascade. The mechanism of the rolling up is explained.
Subharmonic Oscillations of Nonlinear Feedback Control Systems
Authors: Ogata Katsuhiko 
Published: January 2022

Abstract
This paper presents an analysis on subharmonic oscillations as responses of nonlinear feedback control systems. The non-linearities treated in this paper are those whose input-output characteristic curves show saturating or limiting characteristics and are skew symmetric with respect to their origins. The analysis shows that the outputs of such nonlinear systems will oscillate either with the input frequencies or with odd order subharmonics of the input frequencies. This paper also presents a design aid for eliminating the possibility of subharmonic oscillations. Electronic analog computer techniques were employed to obtain the experimental results presented here.
Activity of Cell on Micro Stripe Ridges After Force Field Stimulation With Centrifuge
Authors: Hashimoto Shigehiro , Yonezawa Hiroki 
Published: January 2022

Abstract
Does response of a cell depend on the history of the direction of mechanical stimulation? A mechanical force field generated by centrifugal force is applied to the scaffold plane in the present study. To control the cell direction (0, 45, 90 degrees) with respect to the tangential force, striped micro-ridges in 3 directions were machined on the scaffold surface by photolithography technique. The behavior (movement, and deformation) of each mouse myoblast after cultivation in the tangential force field for 5 hours was tracked for 10 hours by time-lapse images. Experimental results show that the velocity of each cell migration tends to increase regardless of two-dimensional projected area on the scaffold by hysteresis of exposure to tangential force field perpendicular to the longitudinal direction of the cell. The experimental results will lead to the elucidation of the effect of the direction of force stimulation on cells.
Complex Material Behavior Seen With Novel Internal Cathode Tubular Solid Oxide Fuel Cells
Authors: Hartwell Alexander R. , Ahn Jeongmin 
Published: January 2022

Abstract
Rapid climate change and the rising frequency of extreme natural weather events that it causes motivate a paradigm shift in how energy is produced, directing much research interest towards combined heat and power (CHP) systems. With the fuel flexibility offered by solid oxide fuel cells (SOFCs) and their need for high operation temperatures, combustion systems become obvious targets for integration. The fuel-rich combustion of natural gas can produce synthesis gas, while providing the heat necessary for SOFC operation. To remedy issues associated with degradation of cell components, tubular SOFCS (tSOFCs) are best suited to this application. To match the environment present within the combustion chamber, tSOFCs must be turned inside-out yielding novel geometry internal cathode-tSFOCs (IC-tSOFCs).
IC-tSOFC development has revealed a wide variety of unexpected and yet fascinating material phenomenon. One example is the unique stress distribution present in these cells during sintering which ultimately leads to cracking. Another is the effect of the exothermic reaction of water formation at the anode which raises cell surface temperatures much higher than that of the environment, to the point of melting metal contacts. These behaviors, though cumbersome, motivate investigation into fundamental ceramic material behavior and ultimately adoption of new techniques to better control ceramic processing.
Thermo-Mechanical Stresses in the Design and Analysis of Thick-Walled Pressure Vessels
Authors: Mohammadzadeh AliReza , Haidar Salim M. 
Published: January 2022

Abstract
In design and analysis of mechanical and structural components, stresses due to the existence of temperature field in the part cannot be overlooked. In some practical cases, thermal stresses make a significant portion of total stresses.
In undergraduate stress analysis courses, the topic of thermal stresses is covered only in cases of uniform temperature rise and in presence of mechanical loads [1], [2]. Stresses induced by means of temperature gradient alone and in the absence of any mechanical loads are completely ignored. Although coverage of thermal stresses is available in advanced textbooks [3, 4, 5, 6, 7], nevertheless, the level of coverage is beyond the scope of undergraduate students’ understanding.
To address this important aspect of stress analysis in our undergraduate curriculum, the authors developed a project in the design and analysis of a thick-walled pressure vessel subject to a high internal pressure and a stiff temperature gradient in the cylinder wall, and they assigned a version of it to the students in the senior level machine design class at their university. Students were teamed in groups of three and were given one month to come up with their stress analysis results and design decisions for choice of bolts selected to fasten the cylinder’s caps to its body. The goal of this paper is mainly to present the pedagogical approach of the stress analysis aspect of this project in the cylindrical portion far away from the cap ends.
Study on Tribological Behaviour of ZnO Nano Additives Suspended in SAE 20W-50 Engine Oil
Authors: Elsoudy Sherif , Akl Sayed , Abdel-Rehim Ahmed A. , Salem Serag 
Published: January 2022

Abstract
In internal combustion engines, significant power losses are directly related to the mechanical friction of engine parts. Therefore, controlling tribological performance for engine lubricants has a major role in limiting those losses. In this study, the tribological properties of traditional engine oil with nano ZnO and oleic acid (OA) as a surfactant have been analyzed. Three different concentrations of 0.2, 0.5 and 1 wt.% were investigated using a pin-on-disc tribometer, according to ASTM G-99 with boundary/mixed lubrication regimes. The generated friction and wear characteristics revealed a remarkable reduction in friction coefficient with a range of 8–10%. Analysis of SEM and EDX was conducted on the worn surfaces. Additionally, the colloidal stability of nano dispersion was performed through sedimentation, FTIR, and Zeta analyses.
Rapid Design and Analysis of Versatile Robotic Platform
Authors: Islam Ariful , Campbell Chad , Merrikin Christian , Duan Shawn 
Published: January 2022

Abstract
To accommodate the ever-expanding data warehouse market, it is necessary to implement a degree of industrial automation to meet maintenance requirements. With the expansion of cloud-based storage and many new and existing companies moving to automate their processes, the need for a more effective method to manage and maintain server warehouses with reduced manpower is necessary.
In order to address the need, this design team has developed and prototyped — a platform that would meet the basic requirements for server retrieval. The model navigates on four wheels driven by stepper motors that allow for differential steering and navigation in an indexed workspace. In order to reach servers on both the top and bottom bays, a chassis with low ground clearance was fitted with a scissor lift mechanism. The two sides of the scissor lift are actuated by two stepper motors with a high-ratio gear reduction.
The operating system for controls and sensors run on Robot Operating System (ROS) and are powered by a Raspberry Pi that can be remotely programmed and operated from a single network connected computer. For precise controllability of electromechanical devices, appropriately sized drivers and sensors were selected. A Simulink-based step response analysis of inrush current and torque was completed to aid in component selection. This computer-based simulation resulted in important data regarding transient and steady state dynamics of the electromechanical system. This information can be ultimately used to design a PI, PD, or PID controller to eliminate steady state and transient state error from the actual robot, ensuring precise control.
Analysis was centered primarily on the lifting, driving, and control mechanisms. The structure of each system was analyzed to ensure proper dimensioning and material selection. At the same time, the mechatronic analysis was completed to ensure lifting requirements were met. Analysis was conducted on the motor shafts, scissor members, gears, and hardware resulting in a robust design. All of the physical parts were initially modeled to meet a minimum safety-factor and were later modified based on the results of finite element analysis studies. This approach will allow the robot to operate safely and effectively regardless of obstruction or human interference.
The design and programming enable a single technician to manage a fleet of robots for large scale operations. Because of the simplicity of the robot, the mechanisms and electronics selected can be modified to accommodate specific customer needs. This electromechanical platform and electrical simulation serve as a basis for future research and development of autonomous data warehouse maintenance.
Integrated System Architecture Development Framework and Complexity Assessment
Authors: Dalvi Akshay S. , El-Mounayri Hazim 
Published: January 2022

Abstract
Systems engineering is the popular top-down systematic approach to understand and develop complex systems. There is a gap between the systems engineering activities and engineering analysis in major system development processes. This paper presents an integrated MBSE development framework with definite and indefinite modeling capabilities to bridge this gap. The framework uses SysML, a system modeling language, to describe its elements from the system architecture’s perspective. A detailed workflow is presented that guides the engineer throughout the modeling process. The workflow establishes traceability throughout the framework. This research uses Functional Mock-up Interface (FMI) standards to integrate system engineering activities and engineering analysis. A district cooling system case study is presented to demonstrate the framework’s capabilities in enabling the system into existence. The system architecture model was developed using SysML language in the Cameo Enterprise Architecture environment. The engineering analysis model used object-oriented Modelica language in the Dymola environment. The analysis results show that the district chiller model developed using Modelica produces chilled water below 6.6 degrees Celsius, satisfying the district chiller’s system requirement. The exponential trend in the system architecture’s complexity pattern is measured and analyzed using complexity assessment techniques. The results show that the structural complexity of the system increases steadily from 2.7080 to 8.1241. However, the behavioral complexity increases drastically from 1.7915 to 59.2686 in the problem domain.
Three-Dimensional Computational Fluid Dynamics Modeling of a 6V150 Diesel Engine
Authors: Liu Zhentao , Zhang Yu , Fu Jiahong , Liu Jinlong 
Published: January 2022

Abstract
Three dimensional (3D) computational fluid dynamics (CFD) engine simulations can guide and/or complement experimental investigations and provide in-cylinder details that cannot be captured by conventional data acquisition methods. The main objective of this study was to establish a 3D RANS model (i.e., reasonable computational cost and running time) that can predict the efficiency and emissions of a 6V150 diesel engine under different operating conditions. The sub-models include renormalized k-epsilon turbulence model, G-equation model, solid cone breakup model (including hybrid KH-RT model and gas jet model), two-step soot formation model, and etc. The model was validated with experimental data from dynamometer tests. The results indicated that the numerical model captured the combustion and emission characteristics that occurred inside the combustion chamber, demonstrating its capability to evaluate engine characteristics during the development and optimization process.
Development of a Digital Twin for Additive Manufacturing
Authors: Machado Michael , Oliveira Eduardo , Silva Leopoldo , Silva João , Sousa João 
Published: January 2022

Abstract
Since the first industrial revolution that companies have been looking to produce more, cheaper and better products. Nowadays, this quest has achieved a new dimension due to the high market competitiveness. Moreover, is also possible to notice an improvement of the quality standards associated with the manufacturing technologies. Both quests have increased demand for new production technologies that are more efficient and sustainable than the technologies they replace. Leading to a continuous need to develop new technologies, improve existing solutions or even merge existing technologies into a single process to reduce intermediate stages during production of new products, reducing the production time of the products.
In recent years, one of the production technologies that has seen a great increase in popularity, and therefore in new developments are the additive manufacturing (AM) processes. This increase in popularity is due to some major aspects, in first place is the fact that AM generates less raw material waste during production that traditional solutions, in some cases the raw material waste is almost zero. In the other hand it also allows for a greater flexibility and continuous change of the production design since it does require fewer, or even no tools, to assist the production, especially AM based on powder bed fusion (PBF).
From a macroscopic perspective, manufacturing technologies need to be able to produce faster, in a more dynamic way and ensuring the quality standards are maintained, represent the fundamental needs for any institution. In order to provide solutions to the previous desired form the industrial stakeholders have been developing the concept of the industry 4.0 and Internet of Things (IoT). These solutions allow for a constant communication between the machines, resulting in a more efficient and control production cycle. However, this objective represents an exhaustive task due to a great variety of problems, ranging from interoperability, communications issues to equipment compliance to data-driven paradigm.
To increase the implementation scope of this paper, will be provided some development and contribution in terms of information modelling in the additive manufacturing area. Therefore, will be analyzed the fundamental aspects for developing a digital twin of the optical system of a PBF machine. Moreover, will be applied the concept of a digital twin to the laser source and to the galvanometric scanner. This process is fundamental for integrating IoT information modelling into additive manufacturing solutions. In the other hand, it will be analyzed how technical information is generated during the process and how this data can be later used for developing a digital twin that is able to connect IoT devices integrating an AM system. After a more theorical analysis is preformed will be presented a simplified prototype unit to test the implementation of the proposed system.
Multi Response Optimization of Friction Stir Process Parameters on AA2024 / SiC Composite Fabricated Using Friction Stir Processing
Authors: Manickam Akash , Kuppusamy Raman , Jayaprakasham Sudha , Santhanam Senthil Kumar Velukkudi 
Published: January 2022

Abstract
Friction Stir processing is used to modify the mechanical properties of the metal by refining the grain structure, which is proven to be effective for selective surface modification and also retaining the properties of bulk. In this present work Aluminium Alloy 2024 is used as a matrix material, which possess poor corrosion resistance and the softness of the material leads to high wear rate. Silicon Carbide (SiC), which has high hardness, high corrosion resistance and withstands high temperature is used as the reinforcement material. The present work aims to enhance the mechanical properties by refining the grain structure, and improvement in the corrosion behavior of AA2024 through surface composite (AA2024/SiC) fabricated using FSP. The Aluminium Metal Matrix Composite is fabricated using Friction Stir Processing by varying the volume fraction of SiC, rotational speed and traverse speed. The process parameters used in this experiment are rotational speed of 1200 rpm, 1500 rpm & 1800 rpm, traverse speed of 44 mm/min, 60 mm/min & 72 mm/min and volume fractions 8%, 16% & 24% of SiC. The experiment is conducted using Taguchi’s L9 Orthogonal array considering three factors at three different levels. A square pin tool of H13 steel with hardness of 60 HRC is designed and fabricated to provide better material flow of the reinforcement particles. The Silicon Carbide (SiC) particulate reinforced Aluminium Metal Matrix Composite (MMC) has been successfully fabricated through single pass FSP.
The tensile test were carried out using universal testing machine as per ASTM E8 standards to determine the elongation and the ultimate tensile strength (UTS) of FSPed AA2024/SiC composites and the corrosion rate were evaluated using immersion corrosion testing method by weighing the before and after weights of the samples as per ASTM G31-72, 2004. Grey Relational Analysis (GRA) is performed on the multiple response test results to find the optimum friction stir process parameters. Analysis of Variance (ANOVA) is performed to determine the most significant contributing friction stir process parameters at a 95% confidence level.
Influence of In-Process Cryogenic Cooling on Mechanical Performance of Friction Stir T6 – AA 2900 Alloy Weldments
Authors: Ashwath P. , Anthony Xavior M. , Jeyapandiarajan P. , Joel J. 
Published: January 2022

Abstract
Al-Li-Cu alloy A12195-T84 is used extensively in the aerospace launch vehicle external fuel tank structures. Aerospace components are generally joined using aluminium alloy materials, which increases the overall payload capacity of the launch vehicle. In this context, friction stir welding (FSW) process could be a potential solution. In this research work, Al2900-T6 specimens hot extruded were welded by FSW, using different parametric combinations of tool rotation and welding speed. In process cryo cooling was employed to dissipate the heat generated during the FSW. Microstructure and mechanical properties of the weldments were examined for both in-process cryo cooling and normally cooled conditions. It was observed that the grain size of the nugget zone (NZ) got refined because of the in-process cryogenic cooling during FSW. It was also discovered that microhardness was more in case of in-process cryo-cooled weldments as compared to naturally cooled weldments. Micro-hardness of the NZ was observed to be highest due to formation of finer grains because of the in-process cryogenic cooling. In-process cryogenic cooling has also improved tensile properties such as yield strength and % elongation of the FSW weldments.
Experimental Measurement of CID- and Vent-Activation in Cylindrical Lithium-Ion Batteries
Authors: Li Weisi , Crompton K. R. , Ostanek Jason 
Published: January 2022

Abstract
Two pressure-activated safety devices, a current interrupt device (CID) and a vent mechanism, are commonly built into the cap structure of cylindrical 18650 lithium-ion cells to isolate the cell electrically and relieve internal cell pressure prior to case rupture, respectively, in an abuse or thermal runaway event. The activation pressure for these two mechanisms, and how it varies with temperature, is an important parameter for the thermal runaway models incorporating electrolyte evaporation, gas generation and venting. This paper presents a method to extract the geometry of four commercial 18650 lithium-ion vent cap assemblies and measure the CID- and vent-activation pressures with a customized experimental setup. The experimental data were collected at ambient temperature and 100 °C. The CID-activation pressures of the MTI, LG MJ1, K2, and LG M36 caps were 1.058 ± 0.053, 1.293 ± 0.119, 0.997 ± 0.292 and 1.393 ± 0.113 MPa at ambient temperature and 0.920 ± 0.076, 1.066 ± 0.068, 0.834 ± 0.057 and 1.083 ± 0.077 MPa at 100°C, respectively. The vent-activation pressures of the MTI, LG MJ1, K2, and LG M36 caps were 2.308 ± 0.196, 2.202 ± 0.083, 2.190 ± 0.372 and 2.363 ± 0.199 MPa at ambient temperature and 1.919 ± 0.132, 1.866 ± 0.084, 1.781 ± 0.355 and 1.799 ± 0.284 MPa at 100°C, respectively. The experimental setup may be used in future studies to measure activation pressures of future cylindrical cells. The CAD model of the caps may be used to develop a finite element model (FEM) to simulate the CID- and vent-activation pressure and a computational fluid dynamics (CFD) model to design more reliable and effective CID and vent mechanisms.
Microfluidics-Based Fabrication of a Hele-Shaw Cell Device for Drop Coalescence Imaging
Authors: Emeigh Carson , Zhang Haipeng , Ryu Sangjin 
Published: January 2022

Abstract
The Hele-Shaw cell has been well used for various flow studies because it can simplify analyzing the flow of interest to two-dimensional creeping one. The Hele-Shaw cell consists of two parallel flat plates with a very small gap between them. When a working fluid is injected through this narrow gap, two-dimensional Stokes flow is generated with an extremely low Reynolds number and negligible flow velocity normal to the plates.
Applications of Hele-Shaw cell devices include experimental studies of drop coalescence, Stokes flow, and confining cells to a 2D plane, and they usually depend on cameras to capture phenomena of interest from the experiment. The quality of the collected images largely depends on the optical quality of the Hele-Shaw cell. Therefore, it is favorable to reduce the degree of light attenuation through Hele-Shaw cells.
Previously we fabricated a Hele-Shaw cell using polydimethylsiloxane (PDMS) and soft lithography, which are common in microfluidic fabrication, to study drop coalescence with high-speed imaging. It was found that the frame rate of high-speed imaging was limited by light intensity, which was affected by light attenuation through PDMS, and thus the very initial stage of the neck growth during coalescence was not captured. To overcome this limitation, an advanced fabrication method of the Hele-Shaw cell has been developed to incorporate a glass observation window in the PDMS part of the cell.
The previous and newly developed Hele-Shaw cell devices were compared in terms of local intensity and contrast, and improvement in image quality was confirmed. Our method has the following advantages. First, the thickness of the PDMS layers is controllable and thus the attenuation of light intensity can be reduced. Second, the glass-based observation window can enable clearer images with reduced image defects caused by PDMS. Therefore, the suggested microfluidics-based fabrication method of the Hele-Shaw cell has the potential to increase the resolution of high-speed imaging and to reduce the difficulty of post image processing.