bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cellulose Nanofibers (CNF)/Carbon Fiber Composites With Enhanced Flexural Strength for Structural Applications
Authors: Bhaganagar Siddharth , Biswas Pias Kumar , Agarwal Mangilal , Dalir Hamid 
Published: February 2023

Abstract
Cellulose Nanofibers (CNF) are produced from plant cellulose microfibers through a facile synthesis process. These fibers are discontinuous, very graphitic, and extremely compatible with the majority of polymer processing techniques; they can be dispersed isotropically or anisotropically. Since they are available in a free-flowing powder form, the dry carbon fiber can be physically modified with the addition of CNF. The effect of the CNF compositions, their morphology on carbon fiber, and subsequent mechanical properties are explored in this paper. The CNF composite nanofiber networks are introduced as interleave layers to improve the interlaminar shear strength (ILSS) of an epoxy/carbon fiber laminate composite. Dry carbon fiber is coated by different volume fractions of CNF (0.6 wt.%, 0.8 wt.%, 1 wt.%) through the strong bath sonication process. Laminates are fabricated by modifying dry carbon fiber surface with CNF resulting in a considerable improvement in the mechanical characteristics as compared to a neat sample. The application of CNF composite nanofiber networks as an interleaved layer in an epoxy/carbon laminate increases the delamination resistance of the ILSS in both 0.8wt% and 1 wt.% CNF enhanced laminates by 27.2%, and 12.4% respectively, but no significant difference is found for ILSS in 0.6 wt.% CNF enhanced laminate. Moreover, a significant improvement is observed in flexural modulus for 0.8 wt.% CNF coated carbon fiber laminate. This suggests that CNF can enhance the delamination resistance and flexural strength of an epoxy/carbon fiber laminate undergoing delamination and deformation. This result is attributed to crack path modification, and load energy absorption by higher modulus CNFs reinforced nanofibers interleave in the laminate resulting in a higher shear modulus to the networks.
Thermal Analysis and Design of Self-Heating Molds Using Large-Scale Additive Manufacturing for Out-of-Autoclave Applications
Authors: Pokkalla Deepak Kumar , Hassen Ahmed Arabi , Heineman Jesse , Snape Thomas , Arimond John , Kunc Vlastimil , Kim Seokpum 
Published: February 2023

Abstract
Autoclave processing is a commonly used state-of-the-art fiber-reinforced composite manufacturing technology, albeit with high capital cost, long cycle times and high energy consumption. Alternatively, out-of-autoclave processing reduces the initial and operating costs while producing composite structures with similar quality as that of autoclave parts. Additive Manufacturing (AM) the scaled-up molds for out-of-autoclave process using carbon fiber (CF) reinforced composite offers design flexibility, enhanced mechanical, and thermal properties in addition to reduction in weight and cost. However, heating of these molds using an oven is still expensive and necessitates an energy-efficient heating process. In this study, resistive heating through heating elements embedded within fiber reinforced composite molds is used as an efficient heating mechanism. The goal is to design wire embeddings and determine the optimal heat flux density to achieve a target uniform temperature of 80°C across the mold surface. To this end, numerical analyses were performed to evaluate the temperature distribution across the composite mold surface for a given wire placement and mold configuration. Constant thermal properties of the 20 wt.% short CF reinforced acrylonitrile butadiene styrene (ABS) were used in the thermal analysis. Time taken to reach the steady state temperature was also estimated. Design guidelines for wire embeddings were included to enable efficient manufacturing of fiber-reinforced composites through out-of-autoclave molds.
Toward the Design of a Kangaroo-Inspired Robot
Authors: Beaster Garrick , Jawad Badih , Fernandez Vernon , Vejdani Hamid 
Published: February 2023

Abstract
In this paper we report on the design and fabrication of a Kangaroo-inspired running robot. The goal was to develop a robotic platform to understand the effects of the leg dynamics on the stability of running gaits. Specifically, we studied the effect of the leg posture and compliance on the self-stability characteristic of spring mass running gait. In our design, we tuned the leg compliance and leg resting posture and studied their effect on the stability performance of the system. The design of this platform was carried out based on the well-known Spring Loaded Inverted Pendulum (SLIP) as a first stage reduced order model. After that, we modeled the segmented leg with a rotational spring at the knee and studied the effect of the spring stiffness and resting posture of the leg on the self-stability of the system. Then, to be able to manage the whole energy level of the system and in order to transition to different energy levels, we expanded the model to a hip-actuated system in which the body can apply hip torque during the stance phase. For the flight phase swing leg control policy, we followed the simple constant angle of attack strategy in which the system lands with a constant leg orientation. The results showed that if the leg posture and compliance were chosen properly, the self stability of the system improves and a simple hip torque controller can manage the energy transitioning in a robust way with high convergence rate.
Effect of Liner Albedo on UVC Irradiation Control
Authors: Mamidi Rachana , Sharifbaev Arvin , Patel Shivani P. , Gacura Matthew , Vanderlaan Gary , Ji Xiaoxu , Piovesan Davide 
Published: February 2023

Abstract
Ultraviolet germicidal irradiation (UVGI) has been used successfully for the sterilization of tools and whole environments. The advantages of this method are numerous. There does not need to be any physical contact with the artifact to be sterilized; the procedure is quite fast and allows for covering large areas. As a drawback, the cost of these systems is often still prohibitive, and the necessity of the light to hit the surface to be effective might leave residual contamination in the shadowed areas within lumens. To avoid potential shadows, the internal surface of an environment can be covered with specific reflective materials appropriate for the wavelength of the irradiation source. We designed a cost-efficient sterilization chamber that uses UVC for decontamination (SHIVA, Small High-Intensity ultra-Violet Antimicrobial chamber.). The design focuses on a decontamination chamber easy to manufacture for rapid deployment. The device can also be used by the general public for sanitizing non washable materials. We tested the control of irradiation dose, based on different types of materials lining the internal part of the sterilization chamber. The reflectance of the material in the UVC Spectrum was critical for the increase of irradiation dose at the target. We tested 3 lining materials (Teflon, Aluminum, and Vinyl) using an 8W UVGI fluorescent lamp in the Ultra Violet-C (UVC) wavelength range, with peak irradiation at 254.3 nm. Variations between linings could provide a variation in dosage up to 30%. We observed that Vinyl reflectivity in the UVC range is close to 90% and provides the best compromise between the price of the lining, and the final irradiation dose provided to the samples. An increase in total irradiation allows for a more energy-efficient system that could utilize batteries rather than electrical energy from an outlet; hence improving portability.
Continuous Stereolithography 3D Printing of Multi-Network Hydrogels in Triply Periodic Minimal Structures (TPMS) With Tunable Mechanical Strength for Energy Absorption
Authors: Guo Zipeng , Yang Ruizhe , Liu Jun , Armstrong Jason , Zhao Ruogang , Zhou Chi 
Published: February 2023

Abstract
A fast additive manufacturing (AM) protocol to fabricate multi-network hydrogels is reported in this work. The gas-permeable PDMS film creates a polymerization-inhibition zone, facilitating the continuous stereolithography (SLA) 3D printing of hydrogels. The fabricated multi-bonding network integrates the rigid covalent bonding and the tough ionic bonding. The elastic modulus and strength could be effectively tuned by varying the ratio between the covalent and ionic bonding networks to fulfill various loading conditions. The printed triply periodic minimal structures (TPMS) hydrogels demonstrated high compressibility for up to 80% recoverable strain. Moreover, the dried TPMS hydrogels show novel energy absorption properties. We fabricated uniform and gradient hydrogels and compared their energy absorption capability. The anisotropy and quasi-isotropy behavior of TPMS structures were analyzed using simulation studies, providing insights into designing and controlling the TPMS structures for energy absorption. The results showed that the gradient TPMS hydrogels are preferable energy absorbers and have potential applications in impact resistance and absorption.
The Design Evolution of a Lower Extremity Exoskeleton Device for Leg Muscle Rehabilitation
Authors: Fusilero Patrick , Reyes Andres , Trejo Rodrigo , Madireddy Indeever , Vemuri Aayush , Zaidi Sohail , Viswanathan Vimal 
Published: February 2023

Abstract
The proposed design of the robotic-assisted pneumatic knee-brace is activated by using surface electromyographic (EMG) sensors to activate motion for rehabilitation exercises. These muscles are actuators powered by a pneumatic system that expands or contracts depending on the compressed air entering the system. An Arduino-based controller performs the pneumatic control. The first design consisted of two fluidic muscles mounted on a human leg where several EMG sensors were placed on the upper part of the leg randomly to activate the controllers. This device is currently further modified for patients who have undergone total kneed replacement surgery and need leg rehabilitation exercises to recover. In this design, multiple fluidic muscles are incorporated to minimize the reaction time of the device. The brace is designed to mount on a knee of a sitting person and consists of four bars (two bars are mounted on the thighs and the remaining two on the calves). EMG sensors are placed on six muscles, including Vastus Medialis, Vastus Lateralis, Rectus Femoris, Semitendinosus, Biceps Femoris, and Semimembranosus. The new knee brace is fully characterized by mounting it on various sitting persons’ legs. In the current experiment, a healthy person’s legs are targeted. The leg motion is being investigated as a function of air pressure inside the fluid muscles and the location of EMG sensors on the legs for various age groups. The current presentation will include the systematic design improvement in our knee-brace device and its applications. The software that processed the EMG sensors was modified to reject the input noise to give an accurate and fast response. The details of the software and its processing will be discussed in greater detail. The device characterization results will be summarized for practical applications.
Mathematical Modeling of a Piezo-Actuated Cantilever Beam With Interferometer Feedback
Authors: Kochavi Jordan David , Xing Siyuan 
Published: February 2023

Abstract
Laser interferometry, commonly used in high-precision motion control systems, is rarely adopted in experimental vibration analysis because their installation and mounting are invasive to dynamical systems. However, new technology in high-precision manufacturing, such as vibration-assisted machining, has shown the meaningfulness of using laser interferometers implemented in motion control systems for vibration analysis, system identification, and feedback control. To this end, this study investigates the use of laser interferometry for vibration analysis through a piezoelectrically actuated cantilever beam. The complete dynamics of the cantilevered beam with a piezoelectric actuator and a laser interferometer is modeled through the Euler-Bernoulli beam theory. Through the method of separation of variables, the original continuous system is transformed into a discrete system represented in a state-space form. The response of the beam is analytically predicted, then compared with the numerical result from a multibody model constructed in Simscape. The frequency response at the retroreflector is obtained through the Laplace transformation of the state-space form. It is found that the first modal frequencies from analytical prediction precisely agree with their experimental counterpart.
Coexisting Unstable Periodic Motions in the Rössler System
Authors: Xing Siyuan , Luo Albert C. J. 
Published: February 2023

Abstract
This paper studies the coexisting unstable periodic motions in the Rössler system. The periodic orbits are predicted by the corresponding mapping structures of the implicit discrete maps in conjunction with initial and periodicity conditions. The stability of the periodic motions is discussed through eigenvalue analysis of the corresponding variational equations. The harmonic amplitudes and phases of the periodic motions are presented.
Heat Flux Analysis of a Solar Thermal Collector Incorporated With Optimized Involuted Reflectors
Authors: Lim Celine S. L. , Sobhansarbandi Sarvenaz 
Published: February 2023

Abstract
Solar energy plays a vital role in the future of clean energy production due to its availability all year round. Some prominent solar energy technologies, e.g. concentrating solar power (CSP), have the ability to focus/concentrate sunlight for large-scale commercial use. Meanwhile for smaller-scale residential use, solar water heating (SWH) systems are often used to provide hot water for household applications, where the solar collectors are the main components of such systems. The type of solar collector of interest in this study is the heat pipe evacuated tube collector (HPETC). To enhance the system’s thermal and optical efficiencies, this study investigates the incorporation of a custom-made involuted reflector mirror to a single HPETC through employing SolTrace’s optical ray tracing method, where the heat flux around the circumference of the absorber tube can be obtained. The maximum and averaged heat flux is compared between a traditional HPETC system and the HPETC system with the involuted reflectors. The result from this study showed that the HPETC system with an optimized involuted reflector experiences up to ∼ 55.3 % increase in maximum heat flux, and an increase up to ∼ 81.2 % in average heat flux across the absorber tube. Consequently, the HPETC incorporating the custom-made involuted reflectors yields to more collected heat and is capable of providing more hot water to be used for residential SWH applications.
Heat Transfer and Flow Characteristic of Sinusoidal Wavy Microchannel Heat Sink With Different Phase Shift
Authors: Shuvo Abdul Aziz , Bappy Md. Omarsany , Tikadar Amitav , Paul Titan C. , Morshed A. K. M. Monjur 
Published: February 2023

Abstract
Microchannel heat sinks (MCHS) are promisingly utilized to remove large heat flux from microelectronic devices. However, the velocity and thermal boundary layers grow continually in a straight microchannel. As a result, the performance of the microchannel degrades. Disrupting the formation of the boundary layer can enhance the performance of MCHS. One approach to achieve that goal is to develop a wavy channel rather than a straight microchannel (s-MCHS) which hinders the continual growth of boundary layers due to its waviness. Numerous researches suggested that wave amplitude increment and wavelength decrement enhanced the chaotic advection and better coolant mixing. Thus, heat transfer and pressure drop were increased in the MCHS. Although wavelength and wave amplitude in a wavy MCHS (w-MCHS) significantly impact heat transfer performance, the phase shift (θp) between two wavy walls in an MCHS also affects the flow and heat transfer characteristics. When the upper and lower sinusoidal walls are in different phases, the cross-sectional area of the MCHS varies. So, the cross-sectional flow area variation creates an adverse pressure gradient in the MCHS. which causes more flow reversal and better coolant mixing, resulting in improved thermal performance.
The current study aims to study the flow and heat transfer characteristics in w-MCHS for three different phase shifts, θp = 0, π/2, π, under laminar flow conditions. Re ranges from 300 to 800 in the study. w-MCHS with phase shift, θp = π/2, π always shows higher Nusselt number (Nu) than s-MCHS and w-MCHS with phase shift, θp = 0. An increase in surface area due to phase shifts, θp = π/2 and θp = π in wavy MCHS, is negligible and the enhancement in heat transfer of phase-shifted w-MCHS is caused by interruption, reinitialization, and reattachment of boundary layers. In the current numerical study, Nu was found to increase with the phase shift and found 7 times higher than s-MCHS at phase shift, θp = π for wavelength (λ) = 3.5 mm. Besides higher heat transfer and better coolant mixing, the phase shift in wavy MCHS causes increased shear stress and pressure drop due to chaotic flow in wavy MCHS.
The Design of an Open-Source 3D Printable Humanoid Robotic Hand: CHUCHU
Authors: Harling Joseph , Yeh Eric , Ma Gloria , McCusker James , Cuckov Filip 
Published: February 2023

Abstract
One of the heavily desired aspects of human functionality to implement into robotics is the dexterity of our hands for manipulating objects. As it stands, there is a healthy market for robotic hands; however, the market is heavily weighted on either end of the price-functionality spectrum. A hand can provide exceptional human-like features and flexibility but is priced far out of range for small groups or individuals. Or the hand is below $2k but has limited characteristics that mimic the human hand.
This project details the Cognitive Hand Unit for Collaboration with Human Users (CHUCHU), a humanoid robotic hand designed to be affordable, accessible, and comparable in features to other solutions on the market. Its 3D-printed fingers feature fully actuated joints that are controlled by linear actuators with positional feedback, while a spring tendon system is used to manipulate the underactuated joints to keep them compliant. The fingers feature force sensors to provide feedback to the PCB electronics containing the microcontroller and circuitry. The microcontroller utilizes Micro-ROS to receive and send feedback to Linux workstations for overall control.
The resulting iterations of the fingers were subjected to mechanical stress testing for qualification and comparison. Along with this, an analysis of the inverse kinematics of the design is presented in this paper.
Design of a New Vehicle Front End Structure to Optimise Crashworthiness
Authors: Elmarakbi Mohab , Combrinck Madeleine , Elmasry Ahmed , Elmarakbi Ahmed 
Published: February 2023

Abstract
Within this paper methods in reducing weight and optimizing the front-end structure, by specifically targeting both new materials and redesigning the cashbox, to improve crashworthiness were investigated. This was accomplished through redesigning the cross-sectional shape of the crash box, trigger location and type of trigger used, and the use of different materials. The optimal crash box design was found to be a hexagonal prism that incorporated a central trigger which reduced the thickness from 2mm to 1mm. Moreover, the ideal material was identified to be SGF/PA6/GnPls. When this optimized crash box was incorporated to the front-end structure and the ideal material applied to the bumper beam, the fully optimized front-end structure reduced the weight by 75%, reduced peak force by 28% and increased specific energy absorption by 94% and 55% for a frontal and side collision respectively.
An Experimental Setup to Study the Fundamental Phenomena Associated With Biomass Combustion
Authors: Silva João Pedro , Teixeira Senhorinha , Teixeira José Carlos 
Published: February 2023

Abstract
During the combustion of solid biomass in a grate-fired boiler, each particle experiences a sequence of processes which include heating, drying, devolatilization, and char combustion. Furthermore, in the gas phase, products may react with oxygen. As it is impossible to maintain repeatable and fully controlled environments, and to monitor all the dynamics involved in field-scale experiments, it becomes necessary to perform investigations at a small scale. This should be sufficient to provide a controlled environment, and large enough to define realistic conditions. In this way, to evaluate the thermal behavior of biomass particles under an oxidative atmosphere and determine the composition of the flue gas released into the atmosphere, a small-scale reactor was developed and presented in this paper. The results of the different mass loss profiles at different combustion conditions and with samples with different size are presented. Additionally, the composition of the gases released over the devolatilization period was determined using a gas chromatograph and they are here correlated with the reactor temperature. This work proved to be very useful since it is important for the computational modeling of industrial boilers and is required for the design and operation of biomass combustion equipment. In the future, this study will be very valuable to develop a computational tool to analyze the combustion process inside an industrial grate-fired boiler.
Effect of Tool Material and Process Parameters on Surface Conditions in Single Point Incremental Forming (SPIF) of Polymeric Materials
Authors: Ragai Ihab , Goldstein Joe , Meyer Cayla , Upcraft Clayton 
Published: February 2023

Abstract
Single point incremental forming (SPIF) is a relatively new process for forming sheet products. Typically, the sheet is clamped into a fixture and is incrementally formed by moving a hemispherical end-mill tool using a multi-axis CNC milling machine. The tool deforms the material in each pass until the desired geometry is achieved.
Friction between the tool and the formed sheet can have detrimental effects on the final geometry. The increase in friction coefficient can result in a significant decrease in sheet formability due to excessive thinning and subsequent fracture. Additionally, tool rotational speed may also contribute to the surface roughness of the formed part. The interaction between the tool and workpiece materials over relatively small areas of surface asperity is typically where friction and subsequent damage take place.
The purpose of this research is to study the effect tool rotational speed as well as tool-workpiece material interaction on the surface condition and formability of formed components. Three polymeric materials have been considered herein, namely polypropylene (PP), polycarbonate (PC), and polyvinyl chloride (PVC). Spindle speeds varied from 600 to 1800 rpm. Four tool materials were also investigated, namely stainless steel, copper 110, beryllium-copper, and thermoplastic syntactic foam. Full factorial design of experiments took place. The parts were allowed to form until fracture takes place. Subsequently, the height of the cone was measured and used as representation of formability. Additionally, surface roughness and asperity height distribution were analyzed using both profilometry and microscopy. The aim is to explore possible correlations between process parameters and surface condition and their effect on single point incrementally formed shapes.