bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural Frequency and Mode Shape of a Shaft With Elastically Mounted Rotary Inertia From Governing Equations With Dirac Delta Function
Authors: Hassanpour Pezhman 
Published: February 2023

Abstract
This paper addresses the exact solution of a shaft’s free vibrations with a concentrated rotary load within its intervals. A new approach in deriving the governing equation of motion of such systems is demonstrated with the fundamental difference from the classic approach being that the dynamics of the concentrated rotary load is taken into account in the partial differential equation rather than the boundary conditions. The properties of Dirac delta functions are used to represent the concentrated loads. The Dirac delta function appears as a coefficient in the governing differential equations. The specific technique to solve such differential equations is presented. The solution derived using this technique is fundamentally identical to the solution of the classic method; however, the proposed approach offers a simplified and more straight-forward route to the derivation of the characteristic equation. As an example of the application of the proposed method, the characteristic equation, natural frequencies, and mode shapes of a shaft with an elastically attached flywheel are derived.
Matrix Pattern Micromarkers for Tracking Local Contractile Movements of Myotubes Cultured on Thin-Film Scaffold
Authors: Hashimoto Shigehiro , Sakai Shusei 
Published: February 2023

Abstract
To measure the distribution of local contractile movements in the layer of the myotubes, the movement of the matrix pattern of micro-markers placed on the back surface of the thin film to which the myotubes were attached has been tracked in vitro. A matrix pattern of micro-markers (diameter 4 μm, height 2 μm, spacing 30 μm) was created on the back surface of a polydimethylsiloxane thin film (thickness 6 μm) using photolithography technology. Mouse myoblasts were seeded on the front surface of the thin film and incubated for 10 days to differentiate into myotubes. Periodic electrical pulses (amplitude 2 V, pulse period 0.5 s, pulse width 1 ms) were applied between the electrodes of the titanium wire immersed in the medium. The movements of both the myotubes and the markers were observed simultaneously with an optical microscope. Experimental results show that the distribution of movement for each marker is related to the local periodic movement of the myotubes layer. A thin film with matrix pattern micro-markers created on the back side may allow in vitro analysis of the distribution of local repetitive contractile movements in the myotubes layer.
Investigation of the Acoustic Performance of Plantain (Musa Paradisiacal) Fibre Reinforced Epoxy Biocomposite
Authors: Imoisili Patrick , Nwanna Emeka , Enebe George , Jen Tien-Chien 
Published: February 2023

Abstract
Sound is produced by the fluctuation of oscillation waves caused by variations in pressure in a medium containing various frequency ranges, which can be detected by either an animal or a human auditory apparatus and then transferred to the brain for analysis. Noise can be diminished and controlled by using absorptive materials. This is necessary because noise has a negative effect on public health, sharing of knowledge, and serenity, and it is getting worse every day as a result of urbanization and increased affiliated functions. Utilization of natural and synthetic reinforced polymer composites in noise pollution control is an emerging area of research. Natural fibers could potentially replace synthetic fibre reinforced composites due to their low impact on human health and environmental friendliness, according to research. Though academics have been excited about studying their mechanical features, little attention has been paid to quantifying their sound reduction behaviours. Natural fibers, when interacting with a variety of sound frequency and intensity, the varied structures of sound absorbing materials, such as porous structure, hollow structure, multi-dimensional size and length structure, or solid composite materials, having their own distinctive sound absorbing capabilities. This study aims to develop and examine the void content, impact, hardness and acoustic properties of a natural fibre reinforced biocomposites. Natural fibre was extracted from plantain (Musa paradisiacal) fibre (PF), using the water retting method. Extracted fibre wasd used to prepare a fibre reinforced biocomposite using an epoxy resin as the matrix. Biocomposite with 5, 10, 15 and 20 (Wt. %) PF content were fabricated. Impact, hardness and void content analysis was conducted on prepared biocomposite in triplicate. Surface morphology of the fracture surface of prepared biocomposite was examine using a scanning electron microscope (SEM). Porosity and sound absorption coefficient properties of the fibre reinforced biocomposite were also investigated. Test analysis shows that impact, hardness and void content of the biocomposite, increases as PF content increases. Maximum hardness and impact strength were observed at 15 (w %). SEM analysis, shows the existence of cavities on the fracture surface, together with rough fibre surfaces that easily trap air, and this feature tends to boost the biocomposite’s sound absorption qualities.The sound absorption coefficient shows improvement as fibre volume increases in the bio composite. Results suggest that of PF reinforced biocomposites could be less costly, feasible and ecologically superior alternatives to synthetic fibre composites for acoustic applications in areas like building architecture and automotive industries.
Dielectrophoretic Movement of Cell Passing Between Surface Electrodes in Flow Channel
Authors: Hashimoto Shigehiro 
Published: February 2023

Abstract
In this study, cell behavior in microchannels has been tracked for the application of dielectrophoresis to biological cell selection. A pair of titanium surface electrodes integrated with a microflow channel was manufactured by photolithography technology: a triangular electrode with a tip angle of 0.26 rad and a rectangular electrode. A periodic alternating current of a square wave with a period of 0.33 μs was introduced between the electrodes to induce an asymmetric electric field perpendicular to the mainstream direction. During the flow of the suspension of mouse myoblasts (C2C12: mouse myoblast line), the behavior of the cells was measured in vitro. In addition to the shifted movement of cells by dielectrophoresis, the relationship between the distance from the electrode and the change in cell shape was investigated. Experimental results show that the distribution range of the shape of the two-dimensional projection of the cell expands under the influence of dielectrophoresis. The dielectrophoretic effect can be applied to classifying cells not only by cell size, but also by cell deformation.
Performance Evaluation of a Helicopter Main Rotor Hydraulic Control System Using Rotor Equivalent Dynamic Parameters
Authors: Düzağaç Hasan Ali , Çalışkan Hakan , Balkan Raif Tuna 
Published: February 2023

Abstract
Hydraulic control systems are commonly used in helicopter main rotor control applications because of the agility of the system and operational capability under heavy loads. It is significant to obtain better performance from hydraulic control system to ease the helicopter control under heavy loads. In this study, a complete helicopter main rotor hydraulic control system is modeled by using MATLAB/Simulink® to simulate system responses. Kinematic model of helicopter input is obtained. Hydraulic interface of a Flight Control Actuator is obtained. Pitch (α) and Roll (β) angle of stationary swashplate is obtained. Finally, 3 degrees of freedom rotor equivalent model is obtained. To enhance the overall dynamic performance of the system, a PI controller is developed and implemented to the system by an additional actuator. Furthermore, feedback system is modified to have a more stable controller by adding a feedback actuator, to give position of equivalent rotor mass as feedback to Flight Control Actuator. It is concluded that adding a PI controller is highly beneficial in terms of extending the controllable frequency range. Furthermore, modified feedback system is found to be extremely beneficial by decreasing amplitude and improving overall dynamic characteristics.
Gesture Recognition and Master-Slave Control of a Manipulator Based on sEMG and CNN-GRU
Authors: Ge Zhaojie , Liu Weiming , Wu Zhile , Cai Mei , Zhao Ping 
Published: February 2023

Abstract
Surface electromyography signal (sEMG) is the bioelectric signal accompanied by muscle contraction. In gesture recognition, sEMG is a non-invasive, efficient and fast recognition method. For patients with hand amputation, their upper limb EMG signals can be collected, and these EMG signals correspond to the patient’s hand movement intention. Therefore, by wearing the prosthetic hand integrated with the EMG signal recognition module, patients with hand amputation can also make gestures meet their needs of daily life. In this paper, gesture recognition is carried out based on sEMG and deep learning, and the master-slave control of manipulator is realized. At the same time, gesture recognition can also be applied to remote control. Controlling the end of the manipulator at a certain distance with a specific gesture can complete some tasks in complex and high-risk environments with higher efficiency. Based on Convolutional Neural Network (CNN) and Gate Recurrent Unit (GRU), this paper constructs three neural networks with different structures, including single CNN, single GRU and CNN-GRU, and then train the collected gesture data set. According to the results of test set, the input type with the highest accuracy of gesture classification and recognition can be obtained. Among the three neural networks, CNN-GRU has the highest accuracy on the test set, reaching 92%, so it is used as the selected gesture recognition network. Finally, combined with the integrated manipulator, the EMG signals collected in real time by the myo EMG signal acquisition armband are classified by the upper computer, and the results are obtained. Then the control signal of the manipulator corresponding to the gesture is sent to the Arduino control module of the manipulator, and the master-slave control of the manipulator using the EMG signal can be realized.
Influence of the Anisotropic Characteristic on the Accuracy of Acoustic Emission Source Localization With L Shaped Sensor Cluster
Authors: Sun Jiaying , Yu Zexing , Xu Chao 
Published: February 2023

Abstract
Composite materials are increasingly being used in the structure of aircraft. However, this type of materials is commonly encountering damage companied with acoustic emission (AE) events. In order to ensure the safety of structures during service, it is urgent to develop structural health monitoring methods able to localize AE source in composite components as they occur. Kundu et al [1] for the first time proposed a technique using L-shaped clusters to localize AE source in anisotropic plates without knowing the pre-defined velocity. However, the direction dependent group velocity may lead to a large error if the group velocities in some anisotropic materials vary widely. In this paper, whether the characteristic of anisotropy has a great influence on the localization results and the principle of how this characteristic affects the AE source localization results are investigated. The results show that localization results of isotropic plate are obviously better than that of anisotropic plate due to the direction dependent velocities of anisotropic plate, which proves that the characteristic of anisotropy will affect AE source localization results. It is also found that the variation of localization orientation error is consistent with the local velocity gradient.
Empowering Master Students to Pull What They Want to Learn
Authors: Alves Anabela C. , Lopes Nunes Manuel , Braga Ana Cristina 
Published: February 2023

Abstract
This generation of students is a generation that needs a meaningful education. This implies that students must believe that the contents they are learning has a purpose. The best way to do this is by allowing them to pull what they want to learn. However, this is difficult to achieve because the contents of the course is pre-determined by the teachers in a well-defined curricular plan. Still, the authors of this paper and teachers of a course called “Seminars in Industrial Engineering” were able to allow students to do so. Students were encouraged to plan an event, a training session or anything else they wanted, to learn more about Industrial Engineering. The conditions were that students worked in teams and used the schedule time for the lecture (Friday from 6pm to 8pm). This challenge was very welcomed by the students that formed eight teams of five to six members each. Each team approached a different topic in each session. The assessment of the activity involved various components. For instance, teams had to assess colleagues’ activities using similar criteria as the ones used by teachers. The performance of student teams was high. The feedback with this activity was positive and students showed satisfaction and proudness of their achievement. This feedback was gathered using a questionnaire at the end of the semester, and 28 (68%) questionnaires were completed. The main findings pointed out that students appreciated this kind of activities allowing them to learn and develop autonomy and creativity skills.
A Modified Time Reversal Based Probabilistic Imaging Method for Composite Plate Delamination Detection
Authors: Nan Yang , Yue Maoling , Fan Haodong , Du Fei , Wen Lihua , Xu Chao 
Published: February 2023

Abstract
Composite materials have been widely used in aerospace manufacturing because of their low mass, high specific strength, high specific stiffness and good fatigue resistance. However, composite structures are susceptible to damage such as debonding and delamination due to various impacts, vibrations and other external loads. Therefore, it is crucial to regularly monitor composite structures in real-time during spacecraft service to ensure the safety and reliability of the structures. Ultrasonic guided wave is an effective means of monitoring the health of composite plate structures. Delamination, debonding and other damages of composite materials can be imaged and localized using ultrasonic guided wave signals and probabilistic imaging methods. However, due to the large damping of composite materials, the traditional probabilistic imaging method has the problem of low accuracy in damage localization. Therefore, in this paper, we propose a probabilistic imaging method based on a modified time reversal for damage localization and imaging of delamination damage. The proposed method was experimentally validated using a composite plate as a test piece and compared with the conventional method. A fully automated falling hammer impact tester was used to create low-velocity impact damage on specimens to compare the localization accuracy of the time-free reverse method and the modified time reversal method for delamination damage. The results show that the modified time reversal method can better localize and image the delamination damage of composite structures with higher localization accuracy and more sensitive to damage, which verifies the feasibility and accuracy of the method in the localization of debonding damage of composite structures.
Thermal Performance of Phase Change Material Based Heat Exchangers
Authors: Soanker Abhinay , Oztekin Alparslan 
Published: February 2023

Abstract
Phase change materials (PCM) tend to have high energy storage densities and can be an excellent option for thermal energy storage systems. However, the low thermal conductivity of PCM creates a critical problem in effectively transmitting heat energy into these thermal storage systems. One of the solutions is to design these heat exchangers to diffuse heat into the thermal storage systems effectively. Numerical simulations have been performed to investigate the thermal performance of two heat exchanger designs, fin base heat exchanger (FHE) and Helical coil-based heat exchanger (HCHE). Ansys, Fluent has been employed to carry out transient three-dimensional numerical simulations. These simulations are also compared with two different inlet velocities of 0.02m/sec and 0.1m/sec, corresponding Reynolds numbers of 2,012 (laminar regime) and 10,061 (turbulent regime), respectively. FHE melting rates were observed to be much more stable. Total accumulated energy stored during the charging process for the laminar flow regime is higher in HCHE than in FHE. Energy stored is comparatively higher in FHE when the flow is turbulent. The energy discharge followed the same trend as the charging cycle. FHE tends to maintain consistent energy charging and discharging rates compared to HCHE.
Designing a Particle Flow Control Apparatus
Authors: Malik Sheharyar , Anderson Keldon , Goel Nipun , Otanicar Todd , Karimi Soroor 
Published: February 2023

Abstract
Flow control within a particle-based Concentrated Solar Power (CSP) system is essential in determining the heat transfer coefficient, and therefore, the power generation capability of these systems. There are three areas where particle flow control is significant: the receivers, storage tanks, and particle-sCO2 heat exchangers. The focus of this paper is on designing a new mechanism to control the flow in the particle-sCO2 heat exchangers due to the simplicity and potential cost savings when compared to the other areas of interest. The goal is for this new design to have quicker response times in terms of particle flowrate than a slide gate or flow control valve, which are designs currently used. The design resembles that of a chuck mechanism within a drill where a rotation of the sleeve elicits movement of the jaws both vertically and horizontally to close the outlet area of the nozzle. Additionally, this design will utilize the current actuator that is already used within these heat exchangers to reduce the complexity of implementation. The jaws are designed to be closed at an angle of 76° which is just slightly steeper than the hopper leading to the mechanism. Furthermore, this design can be tuned to limit particle bridging and other particle flow phenomena that result in blockages. The prototypes were 3D printed out of polylactic acid (PLA) and scaled up to 100%, 200%, and 400% to be able to observe the velocity profiles of the mechanism more clearly. Experiments are performed with this prototype to compare the inlet and outlet mass flow rates at different configurations of the jaws. The particles used in these experiments are 0.3mm HSP 40/70 that are commonly used in particle-based CSP systems.
Efficient Solar Thermochemical Hydrogen Production in a Reactor Train System With Thermochemical Oxygen Removal
Authors: Patankar Aniket S. , Wu Xiao-Yu , Choi Wonjae , Tuller Harry L. , Ghoniem Ahmed F. 
Published: February 2023

Abstract
Solar Thermochemical Hydrogen Production (STCH) is a promising technology that uses high-temperature heat directly to split water. The authors have previously proposed a Reactor Train System (RTS) that addresses the largest source of inefficiency in state-of-the-art STCH systems — solid heat recovery — by using multiple moving reactors that exchange heat radiatively between STCH steps. In this work, another major source of inefficiency — oxygen removal during metal reduction — is addressed.
Two oxygen pumping schemes are considered — vacuum pumping (VP) and thermochemical oxygen pumping (TcOP). For vacuum pumping, the modularity of RTS enables a ‘Pressure Cascade’ which reduces pumping work by a factor of four and the capex by a factor of five as compared to a single-step VP scheme. The optimized RTS + VP system achieves 31% heat-to-hydrogen conversion efficiency with ceria despite the low efficiency of vacuum pumps at low pressures.
Thermochemical Oxygen Pumping (TcOP) uses a second redox material — SrFeO3 — to pump oxygen. This material is transported in reactors moving in the opposite direction to the main RTS train. The optimized RTS + TcOP achieves morethan 40% heat-to-hydrogen efficiency, while producing twice as much hydrogen per kilogram of ceria as the RTS + VP system.
Heat Transfer in Liquid Nitrogen Cooled Superconducting Transformers: An Experimental Investigation
Authors: Orchuk Sean , Chandra Sanjeev 
Published: February 2023

Abstract
A single-phase, 15-kilowatt electric transformer was modified to replace the secondary copper winding with one formed of Yttrium Barium Copper Oxide [YBCO] superconducting ribbon. YBCO ceramics offer exceptional electrical efficiency at high current when properly cooled to cryogenic temperature. For the present research, a high ratio transformer design induced secondary currents above 200 amperes. This exploited the properties of the YBCO in reducing thermal losses inherent to high currents in conventional conductors. YBCO must operate below its critical temperature of 92K to avoid damage and is typically cooled by immersion in a pool of cryogenic liquid. Immersion cooling makes inefficient use of the cryogen, and a novel cooling method was proposed by the current research. The YBCO was routed within an insulating tube through which liquid nitrogen flowed and the entire assembly operated within a vacuum to minimize heat transfer. To conserve cryogen while respecting the YBCO critical temperature of 92K, the latent heat of nitrogen was exploited and the system designed to operate near the nitrogen boiling point of 77K. The resulting multi-phase system was operated at various conditions and a combined efficiency formula proposed which includes the energy cost of cryogenic fluid. The results demonstrated a 5% efficiency improvement using YBCO materials using a novel tube-cooling arrangement and provide a basis for future research and industrial use.
A Machine Learning Framework for Physics-Based Multi-Fidelity Modeling and Health Monitoring for a Composite Wing
Authors: Makkar Gaurav , Smith Cameron , Drakoulas George , Kopsaftopoulos Fotis , Gandhi Farhan 
Published: February 2023

Abstract
Computational mechanics is a useful tool in the structural health monitoring community for accurately predicting the mechanical performance of various components. However, high-fidelity models simulated through the finite element analysis (FEA) necessitate a large amount of computing power. This paper presents a new approach to develop a multi-fidelity model using artificial neural networks for health monitoring purposes. The proposed framework provides significant savings in computational time compared to a model trained only using high-fidelity data, while maintaining an acceptable level of accuracy. The analysis is conducted using two finite element models, of different fidelity, of an unmanned aerial vehicle (UAV) wing, with damage modeled at six locations, and varying severity. The damage is modeled by changing the stiffness properties of the materials at these locations. The algorithm developed aims at minimizing the number of high-fidelity data points for correcting the outputs of the low-fidelity model. It was observed that the low-fidelity model requires 8 high-fidelity data points to meet the desired error tolerance. This corrected low-fidelity model is then used for locating and quantifying the damage given the strains and frequency by expanding the previously trained network to output damage diagnosis results. The model with applied correction is able to locate the damage with an accuracy of ∼ 94% and quantify the damage with an accuracy of 93%. The performance of the corrected low-fidelity model is compared with a network trained only with high-fidelity datasets and it was observed that the corrected model requires 54% fewer data points as compared to the high-fidelity trained network.