bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation and Parametric Studies of a Linear Fresnel Solar Concentrator Using Air As HTF for Agricultural Drying Applications
Authors: Jaramillo-Cobos Daniela , Delgado Plaza Emerita , Durazno-Palacios Galo , Peralta-Jaramillo Juan 
Published: February 2023

Abstract
To ensure long-term energetic security and stability, it is necessary to work and develop in diversification, availability, profitability, and accessibility to several energy sources, which can be directly applied to all strategic sectors of the society, for example, the agricultural sector. Solar concentrators are devices designed to harness solar energy and convert the solar radiation into heat that can be used by solar dryers. The solar dryer is a technology that can be easily deployed and adopted in rural areas due to its energy efficiency and minimal environmental footprint.
This paper develops a simulation model and parametric studies of a linear-Fresnel-solar-concentrator using air as HTF for agricultural drying applications, specifically to dry mango in Guayaquil, Ecuador. Parametric analyses are performed to evaluate the thermal behavior of the linear-Fresnel-concentrator based in inlet-solar-radiation, the number of primary reflective mirrors, length of the receptive cavity and HTF mass-flux. These studies have shown that the model reaches an equilibrium point with 14 primary reflective mirrors with a length of 7 meters each. Additionally, when there is a flux increase in the HTF, a linear correlation between mass-flux and temperature appears, and for inlet-solar-radiation there is a quadratic correlation.
Research on Coarse Granularity Data Sample Completion Method for District Heating System
Authors: Luo Zheng , Feng Encheng , Lin Xiaojie , Zhong Wei 
Published: February 2023

Abstract
The heating system is an essential part of China’s urban energy system. However, the heating systems in China have varying levels of hardware and software, informationization, and intelligence. The coarse time granularity of actual system data and the missing data brings significant challenges to system analysis and diagnosis. This paper proposes to study the sample completion and granularity refinement of the time-series data of heating systems based on Wasserstein Generative Adversarial Networks (WGAN). The method is validated based on the field data from 2019 to 2020 of a district heating system in Zhengzhou. Besides, the key features affecting the quality of the completion are discussed. After introducing the data processing method of Empirical Modal Decomposition (EMD), the results show that historical data and climate data dominate the quality of the generated samples. The WGAN can generate the samples accurately. When comparing the real data under the same conditions, the accuracy rate reaches 96.4%. This study further refines the sampling granularity of the existing heating system based on the WGAN to provide more accurate samples for system analysis and diagnosis. Overall, the study provides a new data analysis method for theoretical and technical studies under data deficiency scenarios for heating systems.
Techniques for High-Speed Measurement of Accelerating Flame
Authors: Shaffer James , Askari Omid 
Published: February 2023

Abstract
Measurement of time resolved velocities with large accelerations is challenging because the optimal capture rate and pixel resolution changes with velocity. It is known for velocity measurements that high temporal resolution and low pixel resolution increases the velocity uncertainty. This makes selecting acceptable camera settings unintuitive and can result in highly uncertain measurements. For experimental conditions with slow velocities (&lt; 10 m/s) where high temporal resolution is required (because of rapid acceleration) there arises a need for exponentially increasing pixel resolution to minimize experimental uncertainty which is often impossible to achieve experimentally. Desired measurements for early flame propagation have velocities which span a wide range of velocity which can be greater than 10 m/s during ignition and can drop to under 1 m/s depending on the pressure. This rapid velocity change all usually occurs within a millisecond timeframe.
Typical camera-based velocity measurement usually observes either fast- or slow-moving objects with either an average velocity or a velocity at a single time. The goal of this work is to accurately measure such a rapidly changing experimental condition using camera-based measurement and understand the affect various processing methods have on the result. A practical method is presented here to quantify the noise and observe any induced errors from improper processing where measurable physical analogs are used to represent future experimental conditions. These experimental analogs are in the form of rotating disks which have known radial and velocity profiles that will enable the assessment of experimental parameters and postprocessing techniques. Parameters considered include pixel resolution, framerate, and smoothing techniques such as moving average, Whittaker, and Savitzky-Golay filters.
A Device for Reducing Pressure Ulcers in Bedridden Patients Using Fiber Reinforced Elastomeric Enclosures (FREEs)
Authors: Russo Lea , Gondhalekar Mihir , Kota Sridhar , Bassin Benjamin 
Published: February 2023

Abstract
This paper describes the design, development, and prototype testing of a device that can relieve contact pressure to potentially prevent pressure ulcers in bedridden patients by utilizing pneumatically actuated Fiber-Reinforced Elastomeric Enclosures (FREEs) [1,2].
Bedsores, or pressure ulcers, develop in bedridden patients due to constant contact pressure between a patient’s skin and an external (bed) surface. It is estimated that over 2.5 million patients [8] suffer from pressure ulcer developments annually in the United States. High pressure areas of the body include the sacrum and heel, with 36% of pressure ulcers occurring at the sacrum and 30% occurring at the heel. All other body areas each account for only 6% of pressure ulcer occurrence [6]. They are a major concern for low-mobility, patients who are bedridden for an extended periods and are associated with a 5x increase in patient mortality [3]. In addition, pressure ulcers place a significant cost burden on patients. Development of Stage 4 pressure ulcers and associated comorbidities can cost on average $127,000 to the patient [4]. This high cost is mainly due to attending caregiver’s time.
The most common solution for preventing the development of pressure ulcers in bed ridden hospital patients is for the attending nurses to reposition the patients every 2 hours so that the affected areas are relieved of any contact pressure. Repositioning patients is time consuming and strenuous for health care providers. General purpose “dynamic” pressure relief mattresses have shown to be somewhat effective in reducing the development of pressure ulcers. However, they do not effectively target high pressure areas and still necessitate frequent repositioning.
FREEs can be designed to generate a variety of shapes and motions once actuated (pressurized) and serve as building blocks for soft robotic applications. When FREEs, arranged in parallel, are embedded in a material with compatible elastic properties they propagate their deformed shape throughout the surface. These compliant sheets of FREEs are capable of sustaining loads while relieving pressure on high pressure areas of the body. The prototype for the device presented in this paper was designed for relieving pressure on a patient’s heel area. Preliminary test results demonstrate that the prototype device is effective at lifting a patient’s ankle, for patients weighing up to 250lbs, thus relieving contact pressure. The research also demonstrates the viability of developing modular pressure-relieving pads embedded with more advanced FREEs than described in this paper that can be tailored to relieve contact pressure on other affected areas such as the sacrum.
Fuzzy Logic Based Fusion of 2D LIDAR and Depth Camera Data for Robust Perception of Obstacle Distance
Authors: Saksena Harsh , Anwar Sohel 
Published: February 2023

Abstract
Obstacle detection, avoidance and path finding for autonomous vehicles requires precise information of the vehicle’s environment for accurate navigation and decision making. As such vision and depth perception sensors have become an increasingly integral part of autonomous vehicle research and development work. The advancements made in vision sensors such as radars, Light Detection And Ranging (LIDAR) sensors and compact high resolution cameras is encouraging, however individual sensors can be prone to error/misinformation due to environmental factors such as scene illumination, object reflectivity, and object transparency. The application of sensor fusion in a given system, by the utilization of multiple sensors perceiving similar or relatable information over a network, is implemented to provide a more robust and complete system information and minimize the overall perceived error of the system. The primary objective of this work is to implement a smart and robust sensor fusion system using 2D LIDAR and a stereo depth camera to capture depth and color information of an environment. The depth points generated by the LIDAR are fused with the depth map generated by the stereo camera by a Fuzzy system that implements smart fusion and corrects any gaps in the depth information of the stereo camera. The results show that the output of the proposed fuzzy fusion algorithm provides a higher depth confidence than each of the individual sensors can provide.
A Bio-Printing Strategy to Fabricate Geometrically Accurate 3d Scaffolds
Authors: Quigley Connor , Tuladhar Slesha , Habib Md Ahasan 
Published: February 2023

Abstract
3D bioprinting is a promising field in regenerating patient-specific tissues and organs due to its inherent capability of releasing biocompatible materials encapsulating living cells in a predefined location. Due to the diverse characteristics of tissues and organs in terms of microstructures and cell types, a multi-nozzle extrusion-based 3D bioprinting system has gained popularity. The investigations on interactions between various biomaterials and cell-to-material can provide relevant information about the scaffold geometry, cell viability, and proliferation. Natural hydrogels are frequently used in bioprinting materials because of their high-water content and biocompatibility. However, the dominance of liquid characteristics of only-hydrogel materials makes the printing process challenging. Polycaprolactone (PCL) is the most frequently used synthetic biopolymer. It can provide mechanical integrity to achieve dimensionally accurate fabricated scaffolds, especially for hard tissues such as bone and cartilage scaffolds. In this paper, we explored various multi-material bioprinting strategies with our recently proposed bio-inks and PCL intending to achieve dimensional accuracy and mechanical aspects. Various strategies were followed to co-print natural and synthetic biopolymers and interactions were analyzed between them. The dependence of scaffold geometry on the printing process parameters of synthetic polymer and the rheological properties of natural polymers were identified. The successful application of this research can help achieve dimensionally accurate scaffolds.
Numerical Methods for Heat Transfer Computations of Curved Surfaces Using Excel Techniques
Authors: Abdelmessih Amanie 
Published: February 2023

Abstract
The majority of engineers, at some point of their careers, will employ analysis and modeling to a certain degree of complexity. Excel is installed on most engineers’ personal computers. Usually, engineers are competent in using Excel as a spreadsheet to speed up calculations, and are skilled in creating charts with Excel, but very few engineers can use Excel for Numerical Analysis and simulations. Excel is inexpensive unlike the numerous commercial thermal analysis software available in the market. Consequently, small companies and private consultants can find using Excel for basic simulations attractive.
The author published an article in which three Heat Transfer Numerical cases using Microsoft Excel are discussed in detail [1]. Unfortunately, the three cases only address rectangular cross sections. The rectangular cases are easy to address since Excel elements are square. In engineering practice, many circular cross sections are encountered such as cylinders, pipes, rods, etc. In this article four Numerical Heat Transfer practical cases for circular cross sections using Microsoft Excel are introduced and discussed. Each case is solved with two different Excel methods and results are compared with analysis from Patran Thermal. The first case is a pipe with both internal and external surfaces are subjected to isothermal boundary conditions. The second case is a pipe insulated on the outside and isothermal boundary condition on the inside surface. The third case demonstrates the implementation of uniform heat flux to the exterior surface and convection on the interior surface. Finally, the last case is transient conduction with isothermal boundary conditions on both internal and external surfaces of the tube. The details of the simulations and results are discussed in this article.
Bactericidal Effects of Micropillars: A Molecular Dynamics Study
Authors: Singh Akash , Li Yumeng 
Published: February 2023

Abstract
Previous studies have shown that cicada wings has the ability to kill the bacteria on contact. Study of natural bactericidal surface in cicada wings has opened new dimensions of scientific research in bio-inspired chemical-free bactericidal surfaces. To develop and design such biomimetic bactericidal surface, it is necessary to understand the mechanical bactericidal effects of nanopillars in the presence of bacteria, which is extremely challenging due to the small relevant length and time scales. In this study, we have conducted molecular dynamics (MD) simulations to investigate the biomimetic surface with various nanopillars configurations. MD simulations is an exceptional method to simulate materials with small time and length scales with good accuracy and low computational costs. We have simulated the bacteria’s model using coarse-grained modelling and conducting MD simulations. Effects of nanopillar spacing, diameter and height on the lysis process is studied in this article. It is expected that this study will provide us insights on designing nanopillars in terms of height, spacing and diameter for optimal bactericidal effects that can help in the development of chemical-free antibacterial surface.
Acoustic Emission Detection of Circumferential UV-Mechanical Failure of Glass Epoxy Composites
Authors: Yuan Yilin , Shen Gongtian , Xie Fei , Zhang Junjiao , Gan Pengcheng , Shen Yongna , Su Kuan 
Published: February 2023

Abstract
It is a challenging task to understand the damage and failure of ring glass-epoxy composites after ultraviolet aging in practical application. In this paper, acoustic emission (AE) and X-ray computed tomography techniques are employed to study its damage and failure behavior under circumferential tensile loading. The results show that the additional bending effect can’t be overcome when the specimen is stretched, so the strength test is only an apparent result. With the increase of aging time, the number of AE events gradually decreases, but the accumulated acoustic energy increases, which indicates that the longer the aging time, the more severe the damage during loading. The distribution of failure modes caused by circumferential mechanical properties test of specimens can be characterized by X-ray computed technology. In addition, the two complementary nondestructive testing techniques can effectively monitor the damage process inside and outside the specimen, which can provide the basis for the health monitoring of composite structures.
Digital Twin Simulations Based Reinforcement Learning for Navigation and Control of a Wheel-on-Leg Mobile Robot
Authors: Alsaleh Saleh , Tepljakov Aleksei , Tamre Mart , Kuts Vladimir , Petlenkov Eduard 
Published: February 2023

Abstract
Hybrid mobile robots are able to function in a number of different modes of locomotion, which increases their capacity to overcome challenges and makes them appropriate for a wide range of applications. To be able to develop navigation techniques that make use of these improved capabilities, one must first have a solid grasp of the constraints imposed by each of those different modalities of locomotion. In this paper, we present a data-driven approach for evaluating the robots’ locomotion modes. To do this, we formalize the problem as a reinforcement learning task that is applied to a digital twin simulation of the mobile robot. The proposed method is demonstrated through the use of a case study that examines the capabilities of hybrid wheel-on-leg robot locomotion modes in terms of speed, slope ascent, and step obstacle climbing. First, a comprehensive explanation of the process of creating the digital twin of the mobile robot through the use of the Unity gaming engine is presented. Second, a description of the construction of three test environments is provided so that the aforementioned capabilities of the robot can be evaluated. In the end, Reinforcement Learning is used to evaluate the two types of locomotion that the mobile robot can utilize in each of these different environments. Corresponding simulations are conducted in the virtual environment and the results are analyzed.
Design of Human-Robot Collaborative Workstation for the Packaging of Kitchen Furniture
Authors: Ciccarelli Marianna , Moschini Simir , Palpacelli Matteo Claudio , Papetti Alessandra , Germani Michele 
Published: February 2023

Abstract
Collaborative robotics is a key pillar of the smart factory of the future making production systems more flexible and responsive. To this aim, the research communities have made considerable efforts to enable direct interaction between humans and robots in a safe and integrated shared workspace. However, the industrial sector still shows a mismatch between the HRC potentialities and the HRC existing applications. The design is often technology-driven, and coexistence prevails on cooperation or collaboration. Through the case study, this article describes the human-driven design approach that a company should follow to define and evaluate different scenarios and choose the one that best suits its context and workforce. It considers safety, ergonomic, technical, spatial, and equipment issues. It presents an application common to all sectors, the packaging, addressing the complexities of the new production paradigm of mass customization. The design approach has been tested by the major Italian kitchen manufacturer and the resulting collaborative workstation has been simulated by using the software Tecnomatix Process Simulate. The simulation allowed the analysis and evaluation of risks, layout, and performance. The simulation results showed significant benefits in terms of efficiency ensuring a safe collaboration.
Modeling the Burning of Polymer Matrix: Training Collocation Physics-Informed Neural Network
Authors: Ghaderi Aref , Dargazany Roozbeh 
Published: February 2023

Abstract
The combined impacts of thermal, chemical, and physical processes play a significant role in the pyrolysis problems in polymeric materials. Thermal energy is transported into the material via thermal convection when the charring materials are subjected to high-temperature loading. Decomposition of the resin will result in pyrolytic gases and solid leftovers. The material can be split into three zones based on the degree of pyrolysis of the material: (i) charring zone, in which the material entirely decomposes; (ii) pyrolysis zone, in which the material is disintegrating; and (iii) virgin material zone, in which the material has not yet begun to decompose. Physics-informed neural networks (PINNs) are neural networks whose components contain model equations, such as partial differential equations (PDEs). A multi-task learning approach has emerged in which a NN must fit observed data while decreasing a PDE residual. This article introduces PINN architectures to forecast temperature distributions and the degree of burning of a pyrolysis problem in a one-dimensional (1D) and two-dimensional (2D) rectangular domain. The complex, non-convex multi-objective loss function presents substantial obstacles for forward problems in training PINNs. We discovered that adding several differential relations to the loss function causes an unstable optimization issue, which may lead to convergence to the trivial null solution or significant deviation of the solution. To address this problem, the dimensionless form of the coupled governing equations that we find most beneficial to the optimizer is used. The numerical results are compared with results obtained from PINN to show the performance of the solution. Our research is the first to explore fully coupled temperature-degree-of-burning relationships in pyrolysis problems. Unlike classical numerical methods, the proposed PINN does not depend on domain discretization. In addition to these characteristics, the proposed PINN achieves good accuracy in predicting solution variables, which makes it a candidate to be utilized for surrogate modeling of pyrolysis problems. In summary, the pyrolysis model of materials is solved with the PINN framework; We assumed that all thermal properties of a material (thermal conductivity, specific heat, and density) are affected by temperature and degree of burning. While the achieved results are close to our expectations, it should be noted that training PINNs is time-consuming. We relate the training challenge to the multi-objective optimization issue and the application of a first-order optimization algorithm, as reported by others. Given the difficulties encountered and overcome in this work for the forward problem, the next step is to use PINNs to inverse burning situations.