bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Coating on High Performance Heat Resistant Textile Curtains
Authors: Vilarinho Maria Cândida , Araújo Paulo , Teixeira José Carlos , Silva Elisabete , Silveira Dionisio , Soares Delfim , Paiva Maria C. , Ribeiro Daniel , Branco Marisa 
Published: January 2022

Abstract
The protection of human life and goods assumes a growing concern in all forms of activities. The fire and smoke curtains act as a physical barrier to prevent the fire from spreading between spaces as well as to staunch the smoke and heat transfer to adjacent areas, while causing minimal interference. Usually, curtains are based on fiber structures that can be coated to enhance their protective capabilities. Also, the fiber structure can be developed into a complex pattern of 2D and 3D threads, with single or multiple materials that can be tailored to optimize its behavior. The thermal and fire protection depends on the fibers, fabric pattern and coatings.
The present paper reports the development of novel coated structures of fibers used for fire protection curtains. Basalt and glass fibers are used as yarn materials.
Following the certification standards the samples were assessed for their thermal resistance by measuring the temperature differential they provide while their integrity is evaluated. The sample is placed under stress in an attempt to mimic its own weight effect when in service. The temperature is monitored using thermocouples which are placed at both sides of the fabric and the integrity parameter is assessed through the occurrence of fabric rupture and smoke and/or odor release motivated by its deterioration.
Regarding the uncoated samples, the one composed of glass-fiber in both directions presents the best thermal performance. The addition of an alumina coating significantly improves the performance of all samples. However, while a thinner (0.05 μm) alumina layer provides better results for the sample with glass-fiber in both warp and weft directions, the behavior of samples composed of glass-fiber and basalt is superior when a thicker (0.3 μm) alumina layer is used. In both cases, an alumina coating application results in an increase of the gradient temperature (between curtain inside/outside temperatures) of about 38.0% (310.0 °C vs. 427.0 °C for the first and 386.0 °C vs. 526.0 °C for the latter.
Design and Testing of DiMES Carbon Ablation Rods in the DIII-D Tokamak
Authors: Orlov Dmitri M. , Hanson Michael O. , Escalera Jason , Taheri Hadith , Villareal Caitlin N. , Zubovic Daniel M. , Bykov Igor , Kostadinova Evdokiya G. , Rudakov Dmitry L. , Ghazinejad Maziar 
Published: January 2022

Abstract
We present the design of ATJ graphite [1] rods developed for ablation experiments under high heat flux (up to 50 MW/m2) in the lower divertor of the DIII-D tokamak [2], a magnetic plasma confinement device. This work is motivated by the need to test ablation models relevant to carbon-based thermal shields used in high-speed spacecraft atmospheric entries, where the heat fluxes encountered can be comparable to those achieved in the DIII-D divertor plasma. Several different designs for the flow-facing side of the rod are analyzed, including “sharp nose,” “blunt,” and “concave”. The last shape is studied for its potential to lower heat fluxes at the rod surface by increased radiation from trapped neutrals and reduced parallel plasma pressure. We also analyze the possibility of applying a thin (approximately 30 microns) layer of silicon carbide (SiC) to the exposed part of several carbon ablation rods to benchmark its erosion calculations and lifetime predictions. Such calculations are of interest as SiC represents a promising material for both thermal protection systems (TPS) and a fusion plasma-facing material (PFM). [3,4] Preliminary results from the DIII-D rod ablation experiments are also discussed.
Stochastic Dynamics of Rotating Wind Turbine Blades Influenced by Turbulence and Aeroelastic Uncertainties: Recent Developments
Authors: Caracoglia Luca 
Published: January 2022

Abstract
This paper describes the results of recent developments examining the flutter instability of wind turbine blades subject to various sources of input error and noise. The problem is relevant to the safety of the very long blades, usually installed on offshore wind turbine towers. The formulation is based on an implementation of stochastic calculus methods, allowing the evaluation of the effects of both inflow turbulence and aeroelastic load modeling errors and simplifications. The study establishes the general conditions for moment stability Feasibility of this type of analysis for the reliability of the blades is demonstrated by a numerical example.
Oligodendrocyte Tethering Effect on Hyperelastic 3D Response of Injured Axons in Brain White Matter
Authors: Agarwal Mohit , Pasupathy Parameshwaran , De Simone Robert , Pelegri Assimina A. 
Published: January 2022

Abstract
Numerical simulations using non-linear hyper-elastic material models to describe interactions between brain white matter (axons and extra cellular matrix (ECM)) have enabled high-fidelity characterization of stress-strain response. In this paper, a novel finite element model (FEM) has been developed to study mechanical response of axons embedded in ECM when subjected to tensile loads under purely non-affine kinematic boundary conditions. FEM leveraging Ogden hyper-elastic material model is deployed to understand impact of parametrically varying oligodendrocyte-axon tethering and analyze influence of aging material characteristics on stress propagation. In proposed FEM, oligodendrocyte connections to axons are represented via spring-dashpot model, such tethering technique facilitates contact definition at various locations, parameterize connection points and vary stiffness of connection hubs. Two FE submodels are discussed: 1) multiple oligodendrocytes arbitrarily tethered to the nearest axons, and 2) single oligodendrocyte tethered to all axons at various locations. Root mean square deviation (RMSD) were computed between stress-strain plots to depict trends in mechanical response. Axonal stiffness was found to rise with increasing tethering, indicating role of oligodendrocytes in stress redistribution. Finally, stress state results for aging axon material, with varying stiffnesses and number of connections in FEM ensemble have also been discussed to demonstrate gradual softening of tissues.
Steady Flow Studies of the Geometry Effects on the Recirculation Properties at the Iliac Bifurcation
Authors: Carvalho Violeta , Carneiro Filipa , Ferreira Ana C. , Gama Vasco , Teixeira Senhorinha , Teixeira Jose C. 
Published: January 2022

Abstract
The characterization of blood flow patterns is an important task to establish links between hemodynamics and atherosclerosis development, one of the leading causes of death worldwide. Taking into account that the development of cardiovascular diseases and the disturbances in blood flow profiles are characteristic of each individual, the study of the effects of geometry and flow distribution is quite important. For this reason, in the present paper, a CFD numerical model for both simplified and real anatomic iliac bifurcation was developed, taking into account a steady velocity inlet profile.
The results were analyzed, in terms of the recirculation zone length and location, but also in velocity and wall shear stress distribution. It was observed that the bifurcation angle does not affect significantly the recirculation properties. However, significant differences were achieved with different iliac diameters and bifurcation geometry. Moreover, outflow maldistribution in the iliac arteries leads to more complex flow patterns near the iliac bifurcation, intensifying reverse and asymmetric flow patterns. The results of the simulation using the realistic model geometry confirmed that the regions of the geometry prone to develop recirculation areas occur, preferentially, downstream the bifurcation at the outer walls of iliac branches.
In brief, this study allowed a better understanding of the relationship between hemodynamics and vascular diseases, through assessing the distributions of blood velocity and biomechanical forces imposed on the arterial wall by the blood.
Effect of Subcooling on Pool Boiling Heat Transfer Over Minichannel Surfaces
Authors: Dhanalakota Praveen , Mahapatra Pallab Sinha , Pattamatta Arvind 
Published: January 2022

Abstract
In the present work, pool boiling experiments are performed on copper minichannel and flat surfaces at atmospheric pressure with water as the working fluid. The pool boiling experiments are conducted for liquid subcooling of 0K (saturated), 10K, and 20K at atmospheric pressure. Minichannel-1 and Minichannel-2 have a square cross-section with side lengths 1 mm and 2 mm, respectively. The thermal performance of the boiling surface is characterized by the critical heat flux and heat transfer coefficient. The critical heat flux (CHF) is increased by 36–45 % for minichannel-2 and 15–17 % for minichannel-1 compared to a flat surface at all subcoolings. CHF can be increased as high as 287.54 W/cm2 by employing minichannel-2 and 20 K subcooling. Minichannel-1 and minichannel-2 enhanced the heat transfer coefficient as high as 25.21% and 68.59 %, respectively, compared to the flat surface. It is observed that the increase in surface area is the dominant factor in the enhancement of pool boiling heat transfer on minichannel surfaces.
i9Masks: From a Multidisciplinary Summer Project to a Non-Accredited Short Course
Authors: Carvalho Violeta , Rodrigues Cristina , Minas Graça , Lima Rui , Teixeira Jose C. , Teixeira Senhorinha 
Published: January 2022

Abstract
This study presents a research experience with engineering students at undergraduate and graduate levels, during the summer of 2020 at the School of Engineering, University of Minho, Portugal.
Following the first pandemic event in Portugal, from March to May 2020, the Foundation for promoting Science and Technology (FCT) has opened a call for research projects among students and researchers at different Universities. The main aim of these projects was to motivate students to return physically to the campus during a summer course, and to promote a research environment among them.
i9Masks was one of the projects approved by the University of Minho and its main objective was the development of innovative masks in a silicone elastomer for the protection of COVID-19 with the use of state-of-the-art technologies. The development of masks was at the time a very hot topic as well as a fashionable subject for research.
Considering the results obtained, from the final works presented by students, a very positive balance of the experience was achieved.
The i9Masks project was a useful learning experience for engineering education, particularly in Portugal, where the opportunity to participate in this type of “learning by doing” experience is very small.
Beam Element-Based Inverse Finite Element Method for Shape Reconstruction of a Wing Structure
Authors: Dong Tianyu , Yuan Shenfang , Huang Tianxiang 
Published: January 2022

Abstract
Shape sensing technology is the basis for the control system of the adaptive deformation wing. There are various deformation reconstruction methods based on strain information. The inverse Finite Element Method (iFEM) is popular for the advantages of no need to know the structural material and load information. However, iFEM, which mainly uses shell elements, has problems when applied on purely bending beam structures such as large amount of calculation and the waste of more than half of the element’s degrees of freedom. To solve this problem, this paper proposes a beam element-based inverse finite element method. This paper firstly derives the theoretical process of the beam element-based inverse finite element method based on the classical beam bending theory and the least squares variational principle. Then, the proposed method is applied on the main load-bearing structure of the fishbone shape of an adaptive deformable wing. COMSOL is used to calculate the displacement and strain and the FEM strain can be used as the input of the beam element-based inverse finite element method to calculate the reconstruction displacement. At last, the effectiveness and accuracy of the proposed method are verified by comparing the error of reconstruction and simulation displacement.
Fatigue Crack Growth Prognosis With the Particle Filter and On-Line Guided Wave Structural Monitoring Data
Authors: Chen Jian , Yuan Shenfang , Qiu Lei , Ren Yuanqiang 
Published: January 2022

Abstract
Prognostics and health management (PHM) techniques have been widely studied in recent years to increase reliability, availability, safety, and reducing maintenance costs of safe-critical systems, like aircraft and power plants. In these systems, fatigue cracking is still one of the most widespread problems affecting structural safety. However, it is difficult to determine the structure’s fatigue life of an individual system due to uncertainties arising from various sources such as intrinsic material properties, loading, and environmental factors. Even fatigue lives of the same specimens under laboratory tests have large dispersion. To deal with this problem, this paper introduces a fatigue crack growth prognosis method with the particle filter (PF) and on-line guided wave structural health monitoring (SHM) data. The guided wave-based SHM technique is adopted for on-line monitoring the presence and size of the fatigue crack. Besides, the monitored data is sequentially combined for correcting a physical fatigue crack growth model within the PF algorithm. Finally, the data of the fatigue tests of the hole-edge crack is used for demonstrating the proposed method.
Three-Dimensional Numerical Study on the Flow and Heat Transfer in Wick of Loop Heat Pipe
Authors: Shao Bo , Li Nanxi , Chen Yu , Dong Deping 
Published: January 2022

Abstract
In this paper, a three-dimensional model for the evaporator of an ethylene loop heat pipe is developed using CFD method. The flow, heat transfer and phase change of ethylene in a cylindrical evaporator is investigated numerically. In the model of the wick of the evaporator, both the capillary force at the vapor-liquid interface and the flow resistance of the fluid in the porous medium are considered. Fluid-structure coupling heat transfer analysis is also incorporated in the evaporator model. The flow and thermal boundary conditions are determined according to previous experimental results. The shell of the evaporator is made of steel and the sintered nickel powder is used for the wick, whose porosity is 0.6 and the average diameter of the porous structure is 5 μm. The temperature, vapor-liquid phase and pressure distribution in the wick and vapor groove of the evaporator under heating power of 20 W to 60 W are investigated. The simulation results show good agreement with the experimental data. By introducing the capillary force at the two-phase interface, this model can better describe the vapor-liquid distribution in the wick of the cylindrical evaporator. The results may provide some guidance for optimizing the structural parameters of the loop heat pipe evaporator.
On a Framework to Integrate Performance of Helmet Systems for Blast, Blunt Impact and Thermal Loading
Authors: Bagchi Amit , Khine Yu Yu , Mott David R. , Tan X. Gary 
Published: January 2022

Abstract
Helmets have evolved through improvements in shell and suspension materials, and better designs that can absorb ballistic and blunt impact energy. In the past 20 years, threats to US Warfighters have increased with the prevalence of buried improvised explosive devices (IED) simultaneous producing overpressure, blunt and ballistic impact effects, as well as thermal loading in extreme desert conditions. To date, no research has been found in literature that integrates multiple types of loading in helmet system design and performance analysis. The scope of this paper is to integrate such loadings into a design framework that enables trade space analysis across multiple threats. Blunt impact and blast overpressure loadings are simulated using computational fluid dynamics and structural mechanics approaches presented by the authors earlier. The thermal loading and its effects are modeled as buoyancy-driven natural convection, i.e., flow generated by the body’s thermal plume, and forced convection due to ambient wind to assess each design’s efficiency in facilitating evaporative cooling via perspiration and quantified by transport of moisture-laden air away from the head. Blast overpressure and blunt impact loadings, along with thermal loading, are used for multiple configurations of the helmet suspension system as representative cases. The results from the simulated cases are integrated within a framework combining the effects of the loadings to assess helmet system design. We hope that this paper suggests ways to generate a functional representation integrating multiple loadings in protection system design.
Frequency Response of Primary Resonance of Electrostatically Actuated MEMS Circular Membranes
Authors: Caruntu Dumitru I. , Alipi Marcos , Martinez Miguel , Castorena Pedro 
Published: January 2022

Abstract
This paper deals with the amplitude-frequency response of primary resonance of electrostatically actuated MEMS circular plates. The partial differential equation of motion describing the motion of the membrane is nondimensionalized. The dimensionless equation includes the dimensionless parameters describing the effects of electrostatic, Casimir, van der Waals, and damping forces. The AC frequency used for actuation is near half of the natural frequency of the membrane. Two methods of investigation are used. The first is the method of multiple scales (MMS), and the second is the reduced order model (ROM). The results of this work show that the Casimir and van der Waals parameters enhance the softening effect of the amplitude-frequency response of the membrane, while the increase of the voltage parameter increases the escape band of the response.
Numerical Simulation of Solder Paste Printing on Through-Hole Components
Authors: Mateus Duarte , Teixeira Senhorinha , Rodrigues Nelson , Carvalho Violeta , Santos Duarte , Velosa Joao , Soares Delfim , Teixeira Jose 
Published: January 2022

Abstract
The increased demand for smaller and more reliable electronic devices, pressures companies to tune and innovate the production methodologies, always aiming to decrease the production time while maintaining the products’ quality. In the manufacturing of a Printed Circuit Board - PCB, there are two main types of electronic components, namely, Surface-Mount-Devices and Through-Hole components. Both connections are achieved through soldering, an essential manufacturing process that greatly affects the quality of the final product, and may compromise the lifetime of the PCB.
While SMD components are commonly soldered by a reflow process, TH components are generally soldered by a wave soldering process. However, a PCB is generally composed of both types of components. Since both processes are too different in nature, the manufacturing of the board requires two separated mounting lines which represent increased costs and production time. Taking this into account, the present study investigates the usage of the reflow solder printing to deposit the solder paste on through-hole apertures both experimentally and numerically. In general, the results were similar showing a tendency for the solder paste to deposit on the aperture’s right side. Nevertheless, the numerical model predicts a filling area greater (by 22%) than that verified experimentally.
Electro-Mechanical Design Toward an Open-Sourced Robotic Hand Exoskeleton for Management of Neurological and Neurodegenerative Disorders
Authors: Bednar James E. , Schwartz Matthew L. , Woo John , Dow Douglas E. , Ma Gloria , Rawlins Marisha , Cuckov Filip 
Published: January 2022

Abstract
Impaired hand motor function degrades performance of activities of daily living (ADL). Exoskeleton devices can assist hand function for ADL, but the associated cost and complexity limit access for many individuals who would otherwise benefit and impedes development for improved devices. A simpler, but functional, open-source design for a hand assistive exoskeleton might expand accessibility and accelerate development. In this paper, we present an electromechanical prototype of a hand exoskeleton that was designed, implemented, and tested for digit extension and flexing. The design and prototype assisted actuation of an individual finger digit using a sliding spring mechanism. The mechanism is a type of underactuated mechanism that converts one degree of freedom linear motion into rotational motion. The resulting prototype was subjected to motion and force testing, with results supporting certain functional aspects of the system. Further development and testing need to be done for the proposed exoskeleton design, especially as an open-source design. Being open-source would widen access, accelerate development, and improve the quality of life for many individuals.
Evaluating the Impact of Cyber-Attacks on Grid-Interactive Efficient Buildings
Authors: Fu Yangyang , O’Neill Zheng , Wen Jin , Adetola Veronica 
Published: January 2022

Abstract
Grid-interactive efficient buildings (GEBs) are not only exposed to passive threats (e.g., physical faults) but also active threats such as cyber-attacks launched on the network-based control systems. The impact of cyber-attacks on GEB operation are not yet fully understood, especially as regards the performance of grid services. To quantify the consequences of cyber-attacks on GEBs, this paper proposes a modeling and simulation framework that includes different cyber-attack models and key performance indexes to quantify the performance of GEB operation under cyber-attacks. The framework is numerically demonstrated to model and evaluate cyber-attacks such as data intrusion attacks and Denial-of-Service attacks on a typical medium-sized office building that uses the BACnet/IP protocol for communication networks. Simulation results show that, while different types of attacks could compromise the building systems to different extents, attacks via the remote control of a chiller yield the most significant consequences on a building system’s operation, including both the building service and the grid service. It is also noted that a cyber-attack impacts the building systems during the attack period as well as the post-attack period, which suggests that both periods should be considered to fully evaluate the consequences of a cyber-attack.