bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Development of a Reconfigurable and Adjustable Compliance System for the Measurement of Orthotic Properties
Authors: Mo Yaru , Qaiser Zeeshan , Johnson Shane 
Published: January 2022

Abstract
Custom foot orthoses (CFOs) are effective in the prevention and treatment of lower extremity injuries (LEIs). However, the current design methodologies of CFOs are not efficient due to the limited consideration of soft tissue impedance, orthotic properties and subjective feedback during the measurement. A new design methodology of CFOs is required to determine the desired orthotic properties including geometry and impedance, which satisfy pressure/load distribution, subjective comfort and reduce iterations. A measurement device which provides an Interface with Tunable Ergonomic properties using a Reconfigurable Framework with Adjustable Compliant Elements (INTERFACE) is developed. The INTERFACE system provides locally adjustable geometry and stiffness for the support of Medial Longitudinal Arch (MLA) by applying a mechanism with six degrees of freedom and three Tunable Stiffness Mechanisms (TSMs). Therefore, the Rapid Evaluate and Adjust Device (READ) Methodology can be implemented by adjusting the interface properties based on the pressure/load and subjective evaluation. The prototype of the INTERFACE system was fabricated to conduct the validation test on 10 subjects, in which the interface pressure/load distribution and subjective feedback in different combinations of geometry and stiffness were recorded. The plantar pressure/load increased with stiffness and geometrical height, and the significance has been demonstrated by a correlation analysis. Subjective comfort can be achieved with different combinations of geometry and stiffness. The proposed INTERFACE system can be employed to conduct the plantar measurement to obtain the desired orthotic properties which satisfy objective and subjective requirements.
On the Vaporization Rate and Flame Shape of Non-Spherical Droplets
Authors: Palmore John 
Published: January 2022

Abstract
Motivated by the study of spray combustion, this work addresses the combustion of non-spherical droplets. The combustion of spray is usually understood through the theory of droplet combustion, and improving this latter theory is the narrow aim of this work. The current work uses perturbation theory to derive a novel model for the vaporization of non-spherical droplets. Compared to previous efforts in this area, the work uses a physics-based approach by incorporating ideas from the asymptotic analysis of Taylor and Acrivos [J. Fluid Mech., 1964]. The perturbation strategy expands the droplet shape using spherical harmonics, and the theory characterizes the shape of the droplet via the Weber number. The introduction of this parameter is key as it is a parameter that can be easily measured in experiments, and thus it can be used to connect the theoretical results with application. The perturbation analysis is performed based around the classical solution of spherical droplet combustion in quiescent flow. The theory indicates that the effect of droplet deformation can be accounted for by a correction to the droplet combustion rate that is simple polynomial function of the droplet Weber number. Results are compared to existing literature, and it confirms the established trend that deformed droplets vaporize faster than spherical droplets. Analysis of the flame shape reveals that the flame remains nearly spherical, however, the mean flame standoff changes with droplet shape. The extension of the theory to high Reynolds number conditions is briefly discussed.
Thermal Performance of Heat Recovery From Gas Turbine Exhaust Stacks Using the Silencer Upstream Sections
Authors: Faqihi Bouria , Ghaith Fadi A. 
Published: January 2022

Abstract
This paper aims to evaluate the potential of incorporating a novel heat recovery method within the simple cycle gas turbine exhaust stacks. The proposed heat recovery system consists of the existing semi-circular sections (nose) of the silencer baffles. In this heat transfer model, gas turbine exhaust air represents the hot side which flows across the parallel silencer baffles. The cold side stream flows inside the semi-circular sections. The proposed heat extraction system offers an advantage of utilizing waste heat from the exhaust stream, without instigating additional pressure drop on the flow.
In this work, heat transfer analysis was carried out to estimate the availability of sufficient surface areas in the aforementioned sections of the silencer. The proposed model was implemented for the application of fuel gas heating such to enhance the gas turbine cycle performance.
The obtained results showed that by using the nose section area of the silencer baffles only, it was possible to recover about 2.7 MW from the total energy available in the exhaust which is normally released in the simple cycle gas turbine exhaust stack. The extracted heat met almost 54% of the heat required to heat the fuel gas in the performance heater.
The paper also presented further enhancements that can be incorporated, such as utilizing the downstream end of the silencer baffles. In addition, the proposed system can reduce fuel consumption, while avoiding undesired pressure drop in the exhaust system.
A Special Strategy for Quadrotors in Aggressive and Singularity-Free Tracking
Authors: Liu Haowen , Yang Bingen 
Published: January 2022

Abstract
Quadrotors are a popular type of unmanned aerial vehicles (UAVs) that have been widely used and extensively researched in recent years. Quadrotors, while exhibiting high agility in maneuvering, generally lack stability. There exist several types of instability in modeling and control of quadrotors. During an aggressive maneuver process, a traditional quadrotor model developed based on Euler angles may encounter singularities due to the Euler sequence. This type of instability can be avoided via quaternion-based modeling.
Although quaternion-based models can eliminate the singularities due to the Euler sequence, there still exist other types of singularities for maneuvers in head-direction and thrust-direction. A UAV usually equips with a camera or other type of sensing device, which is mounted on the front or top of the U AV and which points towards the forward direction. Keeping those sensing devices pointing at the desired orientation can be a difficult task because the definition of reference heading direction vector introduces singularity and renders the mixer of the quadrotor saturated. As a result, the UAV becomes unstable.
In this article, a special strategy in dealing with the head-direction-induced singularity and saturation is proposed. In this strategy, pre-yawing is adopted when a quadrotor’s current heading direction is approaching singularity. As shall be shown, by pre-yawing before the quadrotor passes through the singularity, the quadrotor can converge toward the heading direction faster after exiting the singularity. Also, the pre-yawing strategy can reduce or avoid mixture saturation by reducing the feedback error. Consequently, the proposed strategy can also reduce the deviation from the desired trajectory. The benefits of this new control strategy in tracking are demonstrated through comparison with existing quadrotor models in the literature.
Effect of Self-Actuating Flap on the Aerodynamic Performance of Flat Plate Wing at Low Reynolds Number
Authors: Verma Anand , Kulkarni Vinayak 
Published: January 2022

Abstract
Experimental analysis is performed to study the effect of a self-actuating flap on the aerodynamic performance of flat plate wings at Reynolds number of 90,000 based on their chord length. Here two different aspect ratios (AR = 1,2) of wing models are chosen to study in open circuit low-speed wind tunnel with and without the presence of effectors. The flap is mounted at the two locations (06c, 0.7c) on the suction surface of the wings. The flow around the wing section controls the opening and closing of the flap. It has been seen for a smaller angle of attack that flap remains attached to the wing surface, but after certain pitching angles, the flow separation initiates to occur along the trailing edge, which lifts the flap and adjusts itself in a situation, so as to attach the flow. The lift and drag characteristics for pre-stalled angles are almost similar to both clean and flapped models. Further, all the flapped configurations exhibited a higher value of lift coefficient for high or post-stall angles than the clean models. No significant changes are seen in drag characteristics for clean and flapped configurations for aspect ratio 1. In the AR = 2 model, approximately the same aerodynamic performance is seen with both the locations of the flap, but for AR = 1 configurations, the flap is more effective when it is located at a position of 60% of chord length. For AR = 2 clean flat plate, the CLmax is found as 0.71 at 12°, and flapped models have the CLmax as 0.74 at 18° angle of attack.
A Convolutional Neural Network (CNN) for Defect Detection of Additively Manufactured Parts
Authors: Parvez Mohammad Masud , Rahman Musarrat Farzana , Galib Shaikat M. , Liou Frank 
Published: January 2022

Abstract
Additive manufacturing (AM), fundamentally different from traditional subtractive manufacturing techniques, is a layer-by-layer deposition process to fabricate parts with complex geometries. The formation of defects within AM components is a major concern for critical structural and cyclic loading applications. Understanding the mechanisms of defect formation and identifying the defects play an important role in improving the product lifecycle. While convolutional neural network (CNN) has already been demonstrated to be an effective deep learning tool for automated detection of defects for both conventional and AM processes, a network with optimized parameters including proper data processing and sampling can improve the performance of the architecture. In this study, for the detection of good deposition quality and defects such as lack of fusion, gas porosity, and cracks in a fusion-based AM process, a CNN architecture is presented comparing the classification report and evaluation of different architectural settings and obtaining the optimized result from them. The performance of the network was also compared with the results from the previous study. The overall accuracy (98%) for both training and testing the CNN network presented in this work transcends the current state of the art (92%) for AM defect detection.
Towards Smart Vaccine Manufacturing: A Preliminary Study During COVID-19
Authors: Kumar Vishnu , Srinivasan Vijay , Kumara Soundar 
Published: January 2022

Abstract
Biopharmaceutical community is devising modern techniques to boost the development, production, and distribution of COVID-19 vaccines in large scale with tremendous speed. This has shifted the focus towards smart manufacturing of vaccines through vaccine platforms. Vaccine platforms have great potential to rapidly generate new vaccines and can overcome the challenges of the traditional vaccine manufacturing approach without compromising on safety and efficacy. This preliminary study compares the traditional and modern vaccine manufacturing techniques, reviews COVID-19 vaccine manufacturing scenarios, and presents a framework to critique on the smartness of the novel platform-based COVID-19 vaccine development and manufacturing.
Digital Feed-Forward Gas Flow Rate Control With a Switched Nozzle Valve
Authors: Martin Christopher R. , Batzel Todd D. , Liebmann Ethan H. 
Published: January 2022

Abstract
This work presents the (SNV) approach for feed-forward gas flow rate control, the considerations included in the design of a prototype, and the results of its evaluation using a bell prover. The SNV uses a pulse-width modulation approach to provide inexpensive feed-forward gas flow rate control in contrast to closed-loop systems with thermal mass flow sensors. Attempts for feed-forward digital control of gas flow rate with throttling is usually frustrated by the difficulty of precisely and repeatably locating a throttle body to the precision required. The SNV uses a statically machined transonic nozzle to provide a mass flow rate insensitive to back-pressure for the on portion of the switching cycle. The severe pressure drop usually associated with sonic flow is almost entirely recovered by using a converging-diverging nozzle instead of a plain orifice, so that excellent metering can be achieved with drops as low as 11%.
Uncertainty in the actual delivered flow is found to be ±1% of full scale. Back-pressure insensitivity is found to be ±0.5% up to 88% of the supply pressure. The operator design predicted that operation would be possible up to 100Hz, but actual performance was limited to roughly 33Hz. Unexpected minor quadratic behavior in the valve calibration and a single errant data suggest that the degraded performance is due to migration of lubricant inside the assembly.
A Study of Flow in Atherosclerotic Arteries Using Virtual and In-Vitro Models and Its Implications Regarding Vessel Erosion
Authors: Salinas Manuel , Weber Evan , Veras De La Rocha Paula , Cox Caylee , Yanello Jonathon 
Published: January 2022

Abstract
Despite the prevalence of atherosclerosis in the western world, many questions have yet to be answered about the origin, development, and failure of atherosclerotic lesions. To better understand atherosclerotic events such as formation and vessel erosion, a bioreactor chamber was developed using similitude theory together with human coronary artery parameters for geometry and flow conditions. The chamber was virtually validated using Ansys CFX. Simulations were performed under laminar flow conditions, density = 1060 kg/m3, and viscosity = 3.5 centipoise. We applied a velocity waveform at the inlet modified through similitude theory to match that of a human coronary artery. Zero relative-pressure condition was set at the outlet. No slip boundary conditions were prescribed at the coronary artery walls. The results showed that the novel bioreactor can create flow disturbances like those observed in human atherosclerotic arteries. In our future work, we would like to include vessel compliance and experimental data utilizing porcine arterial tissue. Our overall goal is to delineate the entire repertoire of events that happen during vessel erosion.
Strength and Qualities of Mixed Additive Manufacturing Materials
Authors: Addeo Seth , Nowicki Margaret , McDonald Kenneth , Zander Nicole 
Published: January 2022

Abstract
Filament shredders and extruders greatly expand the additive manufacturing material selection. By using recycled filaments, waste and future costs can be efficiently cut while creating in-house, customizable, filaments. Testing mixed filaments is necessary to determine the physical and chemical benefits and costs of mixing filaments. This work aims to characterize mixtures of Polylactic Acid and Acrylonitrile Butadiene Styrene. Mixtures were characterized through tensile strength testing and differential scanning calorimetry of extruded filament samples. The tested mixed filaments were found to be comparable to purchased filaments, with drastic increases in elasticity and decreases in torsional strength and tensile strength. This study shows that while possible to produce mixed filaments, and in spite of their chemical similarities, mixtures are not comparable in physical strength to pure filaments.
A Micropolar Metabeam With Nonlocal Feedback Control Circuits
Authors: Wu Qian , Huang Guoliang 
Published: January 2022

Abstract
Active control schemes provide emergent wave properties and flexible tunability in mechanical systems. Here, we propose both analytically and numerically a non-Hermitian metamaterial system enabled by piezoelectric patches and electronic non-local feedback control. The metamaterial system is physically realized by a non-local microploar beam with non-local feedback control. Since the non-local feedback control breaks spatial reciprocity, the proposed metabeam supports not only non-reciprocal flexural wave amplification and attenuation, but also non-Hermitian skin effect featuring bulk localized eigenmodes in the finite structure. The non-reciprocal amplification and attenuation phenomena are quantitatively predicted by band structure analyses under both the continuum and discrete spring-mass representation, which can be attributed to the work exchange between mechanical and electric works. The non-Hermitian skin effect and the associated bulk localized eigenmodes are characterized by a topological invariant. In addition, direction-dependent bending stiffness is also demonstrated in the non-local micropolar piezoelectric metabeam with proper transfer functions. The electronically controllable non-Hermitian metabeam could pave the ways for designing future systems such as synthetic biofilaments and membranes with feed-back control schemes.
Development of a Topology-Optimized Structure for Electronics Cooling Under Natural Convection Conditions
Authors: See Yao Song , Ho Jin Yao , Leong Kai Choong , Wong Teck Neng 
Published: January 2022

Abstract
A topology-optimized structure for thermal management is developed. The topology optimization is performed based on the minimization of objective functions under natural convection in two-dimensional space. The Boussinesq approximation is included in the momentum equation to simulate natural convection. A RAMP-style function is applied to the thermal conductivity in the design domain so as to clearly define the solid and liquid regions. The solid region represents AlSi10Mg, a high thermal conductivity aluminum alloy that is used for additive manufacturing, while the liquid region represents the phase change material (PCM). The optimization was computed with COMSOL Multiphysics. The structure is successfully fabricated by Selective Laser Melting (SLM) using AlSi10Mg powder. Experimental investigations of this structure were performed together with two conventional designs fabricated with Al-6061; one with five longitudinal fins positioned radially from the heat source and the other with no surface enhancements. The PCM used in the experiments is RT44HC. The experiments involved allowing the PCM to completely melt at two heat rates of 27 and 48 W. All structures were placed in the horizontal orientation. Our preliminary experimental studies suggest that the topology-optimized structure has a lower rate of increase in base temperature during post-melting compared to the two conventional designs, primarily due to the efficient transfer of heat by natural convection.
Components Residual Stress and Deformation Reduction: An Integrated Process Design for Additive Manufacturing
Authors: Dalpadulo Enrico , Pini Fabio , Leali Francesco 
Published: January 2022

Abstract
Additive Manufacturing (AM) is a key technology in current industrial transformations thanks to the significant benefits that can bring to high-level sectors. Nevertheless, AM-based design approaches require improvements that are fundamental to exploit the potentials of the technology and reduce the lack of process consistency. This work focuses on integrated Design for Additive Manufacturing (DfAM) approaches for product-process design, to meet both functional and technological targets. The key aspects of process design and issues are summarized and the design method to perform metal AM process optimization is presented. The aim is therefore to minimize process-induced defects and flaws of AM-based manufacturing of metal products, such as residual stress and distortions. The approach consists of industrialization task improvement based on modelling optimization and build optimization sub-phases supported by numerical process simulation. Integration of CAD platforms allows embedding these steps to be performed downstream of the product design, which can be achieved through functional or multifunctional optimization techniques as well (e.g. topology optimization, latticing, graded structures/materials). The design method is finally applied to perform the industrialization phase of a high-performance automotive component. The case study is a formula SAE topology optimized brake caliper to be produced by Selective Laser Melting (SLM) process. Process simulation-driven studies on modelling and build preparation subphases (i.e. orientation definition, supports generation, model distortion compensation) are conducted to support the process design. The study demonstrates the part scale level method’s suitability to industrial context to improve industrialization in the redesign of components to be produced by metal AM.
Characterizing Potential Damage to Landers and Their Payloads Caused by Regolith Ejecta During Operations on or Near the Surface of the Moon, Mars, and Other Worlds
Authors: Roux Vincent , Duan Shawn 
Published: January 2022

Abstract
This research established methods of physical testing and analysis to characterize damage to a lander caused by rocket-propelled regolith during powered operations on or near the surface of the Moon, Mars, and other worlds. An emphasis was placed on using commonly available test materials to help lower cost.
Lift-off using different thrusts were conducted in atmosphere from simulated planetary regolith. Testing was conducted with a scale model of a recent commercial lander with functioning scale rocket analogues using compressed gas as a propellant. This enabled testing to be safer and more cost-effective compared to operating rockets that burned fuel.
Methods of quantifying and interpreting potential impact and abrasion damage and dust covering were established using crushable foam plates, adhesive coverings, and selective color processing of test result images.
This testing can be an important and valuable step in a wider testing program to identify key design revisions before incurring the expense and risk to equipment from testing rocket and regolith interactions in a vacuum facility. This testing requires an awareness of the effects of scale and the limits of testing in atmosphere compared to the lower pressure or vacuum at the intended landing site.
Development of Multilayer Insulation Blanket of Aerogel With Ultra-Low Thermal Conductivity
Authors: Li Xiaoyu , Chen Kai , Shen Chengcheng , Xu Zhao , Sheng Qiang , Zhao Haifeng 
Published: January 2022

Abstract
Multilayer insulation (MLI) blanket is one of the most reliable passive thermal-control materials for spacecraft. Existing MLIs are typically composed of layers of high-reflectivity thin films with low-thermal-conductivity polyester netting or fiberglass paper as spacers. However, conventional MLI loses most of its insulating capability at pressures greater than 10−6 Pa.
To solve this problem, a new kind of MLI was developed in this work with metalized polymer layers separated by silica aerogel sheets. Due to nanoporous structures of aerogel spacers, heat transfer is effectively suppressed inside MLI in gaseous environment. Its effective thermal conductivity keff was measured at different temperatures and pressures with the one-dimensional heat transfer method. Then the correlation of keff was developed. The result shows significant improvement in thermal insulation for the present MLI, which can provide broad prospects of application for non-vacuum scenarios and extreme environmental exposure conditions.