bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling of Human Femoral Bone Idealized As Functionally Graded and Laminated Composite Structure
Authors: Kabir Mobashar , Pervez Tasneem , Al-Jahwari Farooq K. S. , Qamar Sayyad Zahid 
Published: February 2024

Abstract
Femur, the largest bone in the human skeletal system, provides critical mechanical support in bearing internal and external loads. It is a sophisticated natural composite with a complex hierarchical construction of multiple layers having varying material properties. This research work explores modeling approaches focusing on localized behavior of bone material under lateral loads. Small elements taken from cross-sections of femur bone are considered for analysis. To simplify the analysis, it is assumed that the chosen elements can be idealized as plate structures. Two representative bone models are presented and their structural response under similar loading and boundary conditions is investigated. In the laminated composite approach, an idealized bone plate is modelled as a layered composite of discrete orthotropic and isotropic layers with a stepped variation in material properties along the thickness. In the functionally graded approach, an identical representative plate is modelled as a functionally graded structure with a gradual change in properties instead. Material properties of femoral bone used in this work were acquired from experimental data available in literature. A higher order shear deformation theory with seven degrees of freedom is then used to obtain deformation and stresses using analytical and finite element methods. Accuracy of the models are validated by benchmarking with 3-D elasticity solutions and published reference data in literature. Preliminary results show generally lower deformations in the functionally graded model with smooth and continuous stress profiles.
Investigation of the Urban Microclimate Variations Based on the Measured Weather Data: a Case Study of Education City and Lusail City of Qatar
Authors: Kabir Nahin , Abdelhafez Habiba , Sezer Nurettin , Hassan Ibrahim Galal , Wang Liangzhu (Leon) , Rahman Mohammad Azizur 
Published: February 2024

Abstract
Due to significant cooling requirements, urban buildings in hot climatic regions require careful analysis of Urban Heat Island (UHI) and Urban Wind Sheltering (UWS) effects for accurate design of cooling systems. Most studies considered microclimatic data from a nearby weather station, estimated by remote sensing or CFD simulation, all of which carry numerous variables and could yield erroneous results. The most reliable source would be to use data directly measured by weather stations in the study area. To this end, this study investigates the UHI and UWS effects in Qatar based on the comparative analysis of hourly microclimatic data obtained from two urban weather stations in Lusail City and Education City and five established airport weather stations across Qatar for the entirety of 2022. From analyzing the difference in temperature (UHI intensity) and wind speed (UWS intensity) of urban and rural areas, a clear increase in temperature and a sharp decrease in wind speed is observed in both studied urban areas. According to the results, the highest UHI intensity recorded was 16.8°C on the 16th of May (summer) at 1 pm, and the UWS intensity was −65.9 m/s on the 17th of March (winter) at 4 pm.
Error Budget of Wafer Bonding Alignment System Based on Machine Vision
Authors: Wang Rui , Lu Sen , Yang Kaiming , Zhu Yu 
Published: February 2024

Abstract
Accurate wafer alignment is the key to achieving wafer bonding accuracy. High precision wafer alignment systems typically use machine vision to locate the aligned Mark on two wafers, and use complex mechanisms to perform multiple composite movements to achieve functionality, making the coupling effect of multiple types of errors more complex and challenging the error budget of wafer alignment systems. This paper proposes an error budgeting method for such machine vision based multi body precision systems. This method takes the Homogeneous Transformation Matrix (HTM) method as the core to model the system error and establish two types of error transfer chains. For the error chain involving visual measurement, an analysis method based on geometrical optics is proposed to consider the influence of the position and orientation errors of the optical path components. Then organize the possible error sources in the system and model the parameters of each error based on actual test results. Combined with the process flow, customize the error model for each link. Finally, perform Monte Carlo simulation. Using the aforementioned method to budget errors for a certain configuration of wafer alignment system, main error sources were identified, and accuracy indicators were proposed based on the alignment accuracy requirements of ± 200nm. The rationality of the error budget conclusion in this study has been verified through experiments on the construction machine.
Four Purchasing Levels in Prototyping
Authors: Fadda Dani , Rios Oziel , Summers Joshua 
Published: February 2024

Abstract
A method for categorizing a physical prototype by reviewing the purchasing demands is offered. Four levels of purchasing are identified to procure materials for developing a physical prototype: (1) complete buyout, (2) buy major components, (3) buy for repurposing, and (4) buy raw materials only. These purchasing levels are presented with examples along with a decision tree to identify the purchasing level for components on any project. A design course, which allows all four purchasing levels, is also described as the background of this paper.
The objective of this paper is to provide a tool for faculty or project mentors to identify the level of their design team’s purchasing demand and anticipate subsequent activities that can follow the purchase. The purchasing level can be aligned with the project requirements even though the level can also be influenced by the pedagogical outcomes of a course.
Numerical Study of Distributed Acoustic Sensing (DAS) for Railway Condition Monitoring
Authors: Jones Michael , Rahman Md Arifur , Taheri Mohammad , Taheri Hossein 
Published: February 2024

Abstract
One of the most paramount factors for the railroad industry is the safe transportation of cargo and passengers. For the safe movement of locomotives, real-time tracking of trains and their cargo is critical and necessary. Current tracking systems face many challenges from weather interference to expensive implementations. Fiber optic acoustic detection has been developed for application to the railroad industry to improve the reliability of tracking locomotives along their route. Due to the wide variety of circumstances that the system could encounter, the in-situ testing of these systems has proven to be highly expensive. To reduce the cost of testing, finite element analysis is used in this study to determine the effectiveness of fiber optic acoustic detection in a variety of circumstances. The numerical results indicated that the properties of the material surrounding the cable have a significant effect on the accuracy, sensitivity, and effectiveness of the system. In particular, the density and Poisson ratio of a material are highly important to the efficacy of the detection system. The more compact material surrounding the fiber, the better acoustic matching occurs, and the stress/strain distribution is more uniform causing a better detection by the fiber optic system. In addition, the location of the fiber with respect to the applied external load is a critical parameter affecting the accuracy and probability of the detection by the fiber optic system.
Mechanical Analysis of an Additive Manufactured Deflecting-Tapered-Land Hydrodynamic Thrust Bearing
Authors: Yasko Isaiah , Downs William , Fais Collier , Ali Muhammad , Wisner Brian , Walker Rick 
Published: February 2024

Abstract
The research conducted here aims to expand the operating load range and offset manufacturing costs of tapered-land hydrodynamic bearings by creating deflecting bearing sectors through use of selective laser sintering. The motivation of this study comes from the fact that the required taper depth of tapered-land hydrodynamic thrust bearings is determined before manufacturing and is dependent on the expected operating axial loads. If the applied load exceeds the range for which the taper depth was selected for, the bearing will not operate efficiently, and an increased rate of wear will occur. Here, the bearing sectors are designed to deflect during applied loading; this acts as a self-governing device that allows the bearings to operate efficiently over a wider range of applied axial loads compared to their traditionally manufactured counterparts. Experimental analysis was conducted on selective laser sintered aluminum alloy tensile samples to obtain necessary material properties. Three bi-directional bearing sectors having an initial taper height of 88.9 μm were modeled with internal features that allow and limit deflection during pressure generation and bearing operation. The internal features can only be manufactured using additive manufacturing techniques such as selective laser sintering. A mechanical analysis was conducted in ABAQUS/Standard using the material data captured from the tensile tests to show that the bearing sectors deflect 38.8 μm, 64.1 μm, and 76.8 μm due to in-service film pressure distributions. The results of this analysis provide evidence that additive manufacturing can be used to expand operating loads and offset costs of traditional subtractive manufactured hydrodynamic bearings through tailoring of internal structures during manufacturing.
Experimental Investigation of Radiative Cooling Potential in Mediterranean Basin Countries
Authors: Farahat Mohamed A. , ElNaggar Shahd , Kader Ahmad M. , Ahmed Shehab , Rashad Muhammad I. 
Published: February 2024

Abstract
Radiative cooling (RC) is a cost-effective and electricity-free method of heat dissipation through infrared radiation, offering potential energy savings and reduced reliance on conventional cooling systems. Its application is particularly advantageous in regions with high energy costs and limited electricity access, benefiting low-income households and developing nations. RC aligns with sustainable development goals, including climate action, affordable clean energy, and sustainable cities, by mitigating greenhouse gas emissions from power generation. However, further investigations are needed in humid regions, such as Mediterranean countries, due to humidity’s impact on RC performance. This study experimentally explores RC potential in the Middle East and North Africa (MENA) region using economically accessible materials. The emission spectrum of materials -in addition to other parameters-can affect their efficacy as radiative coolers, with the atmospheric window (8–13 μm) being crucial for effective heat dissipation. The setup includes emitters and transmitters, isolating the emitter from warm surroundings and utilizing high-transmissivity transmitters within the atmospheric window. Calcium sulfate dihydrate (gypsum) and calcium carbonate serve as emitters, while polyethylene (PE) and polyvinyl chloride (PVC) act as transmitters. Experimental tests conducted under various sky conditions reveal a temperature difference ranging from 0.97 to 5.57 degrees Celsius below ambient temperature. The combination of gypsum as an emitter and PVC as a transmitter demonstrates the most efficient cooling rate. These findings contribute to the understanding and implementation of RC technology in the MENA region, offering a sustainable approach to address cooling needs and energy challenges.
Chaos Detection in Planar Mechanism With Clearance Using Local, Global and Correlation Dimensions
Authors: Yousuf Louay S. 
Published: February 2024

Abstract
A planar mechanism with three moving parts is connected to a cam. The mechanism is consisted from crank arm, connecting rod, flat-faced follower, polydyne cam, and two guides with clearance. The level of chaos is investigated based on the value of the correlation dimension. Local and global embedding dimensions described the exponential function of each point of the contact force with respect to the state space domain. An average mutual information algorithm is used to calculate the value of time delay. Time delay, decorrelation time, and ‘bad’ predict time are used to calculate local, global, and correlation embedding dimensions. SolidWorks program is used in the calculation of contact force at different cam speeds and different guides’ widths. The algorithm code of the dynamic tool is used to calculate local, global and correlation dimensions. Local Lyapunov exponent is calculated using MatLab code of the dynamic tool algorithm based on the values of time delay, local and global embedding dimensions. The investigation of the dynamic simulation of the contact force between the cam and the follower is considered in the presence of crank arm and connecting rod mechanism.
Teaching Engineering Dynamics Using Interactive Pedagogies and Entrepreneurial Minded Learning
Authors: Chauhan Vedang 
Published: February 2024

Abstract
Engineering dynamics is a vital field for many engineering disciplines, but it can be challenging for students due to its mathematical and physical concepts. Traditional teaching tools like textbooks and whiteboards rely on static diagrams and representations that don’t fully capture the dynamic and complex nature of motion. Engineering dynamics demands a more hands-on approach, with advanced tools and technologies like computer simulations, virtual reality tools, and physical experiments enabling students to observe and manipulate motion in real-time. This research explores innovative teaching methods, including interactive and entrepreneurial-minded (EM) learning, to improve students’ engagement, learning outcomes, and conceptual understanding. The module developed involved exciting activities allowing students to apply theoretical learning to experimental setups, collect and analyze data, and write professional reports and presentations. The module aimed to foster an entrepreneurial mindset by encouraging students to identify opportunities, brainstorm ideas, and connect multidomain knowledge for problem-solving. Results showed that the module increased classroom engagement, improved students’ conceptual understanding, and nurtured an entrepreneurial mindset. This research can help educators develop more effective pedagogical approaches to this critical subject, benefiting both students and the engineering community.
Numerical and Experimental Evaluation of an Enhanced Boundary Node Path-Planning Method for Agri-Robots in Dynamic Environments
Authors: Saeed R. A. , Carabin Giovanni , Vidoni Renato , Von Ellenrieder Karl 
Published: February 2024

Abstract
The agro-forestry sector is one of those that could benefit from new technologies and robotic applications to adapt to climate change effects, population growth and globalization. These applications can improve the efficiency and performance of the operations, as well as the products’ quality and traceability. Anyhow, the possibility to automate many of the applications carried out in the open field is related to the development of mobile platforms able to move and adapt to highly unstructured environments. Within this context, this work focuses on the development of a path-planning algorithm for UAVs navigating through an orchard/vineyard environment without colliding with static obstacles (e.g., plants) and/or unexpected ones (e.g., people or other robots operating in the same area). The path-planning strategy is grounded on an enhanced Boundary Node Method (BNM) and a re-planning approach is considered to recomputing and reconfiguring the path in case of unexpected obstacles that prevent the robot from following the original one. The developed method has been firstly evaluated in a simulated environment (i.e., Gazebo simulator), considering different combinations of obstacles and robot tasks. The same numerical experiments were then tested in a real emulated orchard scenario. The results showed good path-tracking capabilities in case of both known and unknown obstacles.
Frequency Controls of O- and X-Carbon Nanotube Reinforced Rings With Light-Activated Shape Memory Polymers
Authors: Li Hongjie , Deng Yan , Fan Mu , Wang Dan , Tzou Hornsen 
Published: February 2024

Abstract
Ring structure has been widely used in aerospace, architecture and other fields. Precise control is required for some precision equipment composed of ring structures. However, the ring structure is lightweight and has high flexibility, so it is easy to be disturbed by external excitation. It is very important to control the vibration of the ring by using sensors and actuators. Traditional passive and semi-active dynamic shock absorbers are mature and effective, but they need to occupy a certain space and cannot be organically combined with the ring structure. Based on the concept of smart structures, smart materials as sensors and actuators are directly pasted on the surface of the ring, forming the sensing and control system of the smart ring structure. Among them, the light-activated shape memory polymer (LaSMP) exhibits low density, large deformation, non-contact actuation and little temperature change during transformation. It is a novel smart material with great application potential. Under ultraviolet (UV) light illumination, the Young’s modulus of LaSMP changes greatly and the shape can be restored before deformation. LaSMP has a small temperature range when driven and produces no electric or magnetic fields, so there are few restrictions on application. The dynamic stiffness and shape memory properties of LaSMP can be applied to the vibration control of structures. Frequency control is an important method in the vibration control of ring structures. By adjusting the natural frequency of the ring, the resonance of the structure under the external excitation of some frequencies can be avoided. The Young’s modulus of the LaSMP changes under UV light illumination. The change in the Young’s modulus will affect the stiffness of the ring and change the natural frequency of the ring. In this study, two distribution types of carbon nanotubes (CNTs) are investigated, namely, the O-distribution type and the X-distribution type. A LaSMP is uniformly distributed on both the inner and outer surfaces of the ring. This study aims to control the frequency of O- and X-CNT reinforced rings by using the dynamic stiffness characteristics of the LaSMP and compare the frequency control effects of these two distributions. The dynamic stiffness model of the LaSMP is introduced and the natural frequency of the laminated rings is given. The natural frequency of O- and X-CNT reinforced rings laminated with LaSMP before and after light irradiation are analyzed. The variation of natural frequency during UV irradiation is studied, which verifies that the LaSMP can be used for frequency control of the ring. Finally, the effects of two distribution types of CNTs on frequency control efficiency are compared.
Multi-Channel Vibration Control of Conical Shells Based on Flexoelectric Effect
Authors: Li Haoran , Fan Mu 
Published: February 2024

Abstract
The flexoelectric effect in solid dielectric is another form of electrol-mechanical coupling, which is different from piezoelectric effect. Flexoelectricity usually refers to the ability of a dielectric body to polarize under non-uniform deformation, which is a electrol-mechanical coupling phenomenon between the electric field and the strain gradient. The flexoelectric smart structure can realize the sensing, vibration control and stability control of the structure, so the flexoelectric smart structure has a broad application prospect in engineering applications.
In this paper, the vibration control of a conical shell with multiple flexoelectric actuators is studied, and the optimal position distribution of the flexoelectric actuators is predicted by using the neural network model. In the physical model, the AFM probe is placed on the upper surface of the flexoelectric patch to induce a high intensity non-uniform electric field on the flexoelectric actuator, thus generating the internal stress of the flexoelectric actuator patch according to the reverse flexoelectric effect. The case studys show that the high intensity non-uniform electric field generated by the AFM probe has almost zero contribution to the electric field in the area far from the contact point, so the stress generated by the converse flexoelectric effect is mainly concentrated near the AFM probe, and the size and shape of the torsion plate have very limited influence on the actuation. Based on the assumption of small deformation and linear displacement, considering the vibration control of multiple flexoelectric actuators on the truncated conical shell, the lateral displacement results controlled by multiple torsional electric actuators can be calculated by the superposition principle. When multiple flexoelectric actuators work together, when the same flexoelectric actuator is in different positions, it may produce opposite lateral displacement at a point on the surface of the truncated conical shell, this situation will make the vibration displacement of the flexoelectric actuator cancel each other. The approximate optimal distribution positions of the multi-channel flexoelectirc actuators were obtained through experimental simulation.
Cast Silicone Robotic Gripper in Underwater Applications
Authors: Liu Wen , Shin Minchul 
Published: February 2024

Abstract
The robotic gripper is widely used in manufacturing and other areas in modern society. Robotic grippers have the advantage of providing precise control and a wide range of torque output and size for different applications. Power sources of robotic gripers are variable like pneumatic, hydraulic, electric, or mechanical systems. Pneumatics gripper is one of the most common and popular types; Pneumatics robotic grippers have advantages of providing wide range of power output, low cost, easy to maintain, and more. At the same time, the pneumatic gripper is more flexible for different sizes. The small pneumatic gripper will still be able to provide strong gripping force and precise control.
Robotic grippers come more in a solid form that is construed by metal or other solid material. The soft robotic gripper is another form of robotic gripper that has the advantages of adapting to irregular shapes, able to withstand blunt force trauma, and able to grip fragile objects. Silicone rubber pneumatic soft robotic gripper combined advantages of pneumatic system and soft robotic to provide a precise control, strong gripping force, adapting to irregular shape, and more.