bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of CFD Model to Study the Spread of Wildfires
Authors: Gonçalves Inês , Marques João , Silva João Pedro , Teixeira José Carlos , Alvelos Filipe , Tavares Teresa , Teixeira Senhorinha
Published: February 2023

Wildfires are a worldwide phenomenon that as an impact on all surrounding forms of life. Studying these events is essential to develop and optimize the tools used for combat and prevention, and its behavior is associated with the state of the vegetation, atmospheric conditions, ground properties, and many others, constituting an expensive and challenging task.

This work presents itself as a complementary work to study the flow over a forest through a CFD model, which causes a modification in the velocity profile due to the drag produced by the forest presence, and the values obtained can be used in a mathematical model to study the fire rate of spread and fireline intensity considering the new velocity field. The CFD model was applied in the commercial software Ansys Fluent.

The results confirmed that the wind is a dominant force during a forest fire, i.e., at high velocities the fire has an aggressive behavior and at low velocities tends to calm down. However, due to the unpredictability of certain weather conditions, it is dangerous to say that a forest fire is fully controlled since its behavior can change in a matter of minutes.
Numerical Investigation on the Suitability of a PCM/Refrigerant Hybrid Cooling System for Lithium-Ion Batteries
Authors: Kittleson Jesse , Muhkerjee Abhijit
Published: February 2023

As electric vehicles become more prevalent, the need for safe, efficient battery packs will drastically increase. Lithiumion batteries are at the forefront of this technology due to their high voltage, high energy density, long lifespan, and low self-discharge rate. The performance and lifespan of a lithium-ion battery pack is closely related to the temperature of the battery pack. Safety is also a concern as thermal runaway can occur at temperatures above 353K. As a result, battery thermal management systems (BTMS) are required to maintain the temperature at a safe level.

The performance of a convective heat transfer and phase change hybrid BTMS has been evaluated numerically using Ansys Fluent. Refrigerant R134a is the primary focus of this paper due to its use in the existing air conditioning system. Its performance is then compared to that of water and air cooling. Paraffin and a paraffin/graphite composite are used as the phase change material (PCM), and their performance is compared to that of aluminum, representing the absence of PCM. Finally, the diameter of the cooling channel is altered to evaluate its effects on heat removal from the battery pack.

It was determined that for all cases water cooling was sufficient to keep the batteries within their optimal range. By contrast, there were no circumstances where air cooling was sufficient to keep the batteries beneath their thermal runaway temperature. At higher Thermal Reynold’s numbers, R134a was able to maintain the battery below the thermal runaway temperature but resulted in temperatures well above the optimal operating temperature.
Multi-Scale Molecular Dynamics Simulation of Fused Silica Under Shock Impact: Parameter Characterizations
Authors: Gupta Tanuj , Woods Tristan , Zhao Huijuan
Published: February 2023

Silica is one of the most abundant substances on Earth. Chemically expressed as SiO2, silica exhibits a complicated phase diagram with multiple crystalline structures (polymorphs) at different temperature and pressure conditions. Under a shock impact, a significant amount of energy is effectively absorbed due to the phase transition of fused silica to stishovite, thereby taking most of the destructive energy away from these structures. Therefore, it is crucial to have a reliable method to investigate the mechanism behind the phase transition between fused silica and stishovite to better adapt this material as energy absorption and protection materials for future combat protection applications. In this work, the multi-scale shock technique (MSST) method is characterized to study the shock impact of fused silica. The BKS potential is employed to define the interatomic potential of fused silica. We calibrated two artificial MSST parameters, Q and tscale, concerning the simulation box size. We revealed the impact of cutoff radius rc on fused silica’s phase transition under various shock velocity conditions. We found that the selection of rc in the BKS potential influences stishovite’s nucleation, formation, and growth at different shock velocity conditions. Future work will expand the MSST method to eliminate the parameter calibration and better predict the material behavior under shock impact.
Layer Dependent Out-Of-Plane Thermal Conductivity in MoS2: A Molecular Dynamics Study
Authors: Rahman Mahabubur , Zhao Huijuan
Published: February 2023

In this work, nonequilibrium molecular dynamics (NEMD) simulations are adopted to calculate the out-of-plane thermal conductivity (TC) variation of MoS2 with respect to the number of MoS2 layers. We benchmark the NEMD method and investigate the role of the heat exchange rate in the in-plane TC calculation. We observe a monotonically increasing trend of the out-of-plane TC to the number of MoS2 layers. The out-of-plane TC of MoS2 is an order smaller than that of the in-plane direction, mainly due to the weak long-range interaction along the out-of-plane path.
Three-Dimensional Computational Fluid Dynamics Modeling of the Combustion Process of a MAN L21/31 Marine Diesel Engine
Authors: Yan Yuchao , Yang Ruomiao , Liu Zhentao , Liu Jinlong
Published: February 2023

In the available literature, information on marine engines is limited for the general researcher. The goal of this study is to provide high quality information on a marine diesel engine that is beneficial to the engine community. Information on a 6L MAN L21/31 marine diesel engine is collected from existing studies and a three dimensional computational fluid dynamics model is built in this paper that can characterize the in-cylinder activities occurring in this marine engine. The good agreement between experimentally measured and model predicted cylinder pressure and heat release rate indicates a good calibration of the numerical model. Simulation results show that sufficient oxygen is still available in the chamber when the exhaust valve is open, suggesting the possibility of further reducing incomplete combustion products by increasing the utilization of excess air. Moreover, the model predictions help to show that the injection settings are already well calibrated for the rated power condition in terms of the balance between fuel economy and clean combustion. Accordingly, future efficiency improvements and emission reductions are suggested to be achieved by the optimization of the chamber shape, which has the potential to further improve the air utilization.
Industry 4.0 Trends in Intelligent Manufacturing Automation Exploring Machine Learning
Authors: Hoover William , Guerra-Zubiaga David A. , Banta Jeremy , Wandene Kevin , Key Kaleb , Gonzalez-Badillo Germanico
Published: February 2023

Current trends indicate that the manufacturing industry is moving toward implementing Industry 4.0 concepts in search of improved adaptability, efficiency, sustainability, and advanced technological implementation. Some of these new technologies include virtual process simulation, automation, machine learning technologies, and the use of IIoT to innovate solutions.

Researchers are focusing on ways to improve the rate and economy of implementing Industry 4.0 concepts in current manufacturing processes. This paper focuses on the implementation of a combination of specific industry 4.0 concepts in a lab environment. There will also be a case study where this research will be applied, and the results discussed. Digital Twins is also a proposed component of the research case study that is implemented using Siemens PLM Tecnomatix tool. Future work is to improve the efficiency of the manufacturing, pick-and-place operation using Deep Reinforcement learning.
Improvement of API Program to Evaluate Three-Dimensional CAD Models
Authors: Joo Sunghwan
Published: February 2023

Many commercial Computer-Aided Design software have been introduced in high schools and undergraduate engineering colleges in the past decades. Basic CAD skills have become the essential engineering skill which all students need to have. Because many colleges offer basic CAD courses as early as freshman course sequences, the size of the class is quite large. That means many assignments for instructors and a lot of time to grade assignments. When instructors grade assignments, they need to open CAD files, check the accuracy of models, and close CAD files again. If they grade multiple assignments or sometime even 100s of assignments required, time to spend to grade those assignments will be tremendous. So, the CAD software API (Application Program Interface) based software was developed by author. The first version of the program was developed in 2018 and presented in the IMECE conference. The program was designed for SolidWorks using Visual Basic for Applications and provides several useful functions. The program opens multiple CAD files and check the critical values including dimensions and closes those automatically. The results are saved in Excel file to review later. The first version of the program was accepted positively by the fellow colleagues. However, there was always room for improvement. Since then, the program has been completely revamped. 1) More functions have been added to the program including the screen capture of open 3d models, 2) The program has been optimized as an independent executable program which run separately from the CAD software, 3) The program now supports multiple CAD software, 4) The program checks the watermark in the files to prevent plagiarism. In this paper, the following topics will be discussed and presented. 1) The problem with manual grading and assessment, 2) History and background of API functionality in commercial CAD software, 3) Previous development of API based evaluation software, 4) Example of the developed API program, 5) Comparison between previous program and new program. 6) Future improvement plan of API program. An actual demonstration of the program will be given during the presentation.
A Method to Account for the Effects of Thermal Osmosis in PEM Fuel Cells
Authors: Ingarra Nicholas , Kobus Krzysztof (Chris) , Maisonneuve Jonathan
Published: February 2023

In PEM fuel cells heat and water management are essential for fuel cell operation. Presently there are two agreed modes of water transport: electro-osmotic drag (EOD) and back diffusion (BD). EOD and BD are obtained from the Nernst-Planck equation. It can be shown that the Nernst Planck equation neglects the impact of thermal osmosis. It must be determined if this assumption on neglecting thermal osmosis is valid, or if thermal osmosis is a strong influencer of net water flow. Thermal osmosis (TO) is not fully understood, and some researchers have made conclusions about thermal osmosis but failed to properly isolate thermal osmosis from other modes of water transport. This work demonstrates that thermal osmosis is neglected in most fuel cell analysis and that thermal osmosis needs to be examined further.
Methodology for the Design of Demonstrative Didactic Prototypes for the Teaching of Renewable Energies Based on Education for Sustainable Development ‘ESD’
Authors: Peralta Juan , Delgado Emerita , Maldonado Fausto , Durazno Galo , Miranda-Delgado Livingston , Prieto Alexander , Reinoso Jose
Published: February 2023

Achieving sustainable development education is one of the challenges proposed to reach many countries by 2030, based on SDG4 [1] A case of interest is teaching for development of energy sustainability in educational institutions [2], where student learning was enhanced with demonstrative didactic prototypes. The development project of linkage with society ESD-ESPOL, professor and students of the careers of Engineering in Mechanics and Electronics in Automation are developing a project for training, Developing educational didactic material that allows learning in aspects of sustainability in the subject of renewable energy, to students at the secondary level.

This work present objective the development methodology the design of didactic prototypes education. To achieve this goal, students have been developing the design and construction of demonstration didactic prototypes to teach renewable energy associated with solar thermal, photovoltaic, water, and wind. The engineering design process includes the form of the conception of the preliminary model to the development of detailed design that includes the movement of the equipment and data visualization that allows the beneficiary to interact with the prototype based on a working guide. As a result, the appropriate methodology of the process ESPOL students must carry out to develop the functional prototype and begin with the team staggering was determined.
Thermal Design and Parametric Study of a Greenhouse in Microgravity Conditions
Authors: Karigiri Madhusudhan Nivedha , Najafi Hamidreza
Published: February 2023

The recent progress in commercial space flights and prospects for interplanetary space missions has attracted more attention towards developing sustainable built environments in microgravity conditions. An important factor in establishing a sustainable living condition for outer space applications is the ability to produce food. The thermal design considerations in a greenhouse have a major impact on the survival, water efficiency, quantity, and quality of plants produced. The extremely low environmental temperatures necessitate the use of heaters which do consume energy. Given the scarcity of energy access, it is important to achieve proper thermal conditions with the lowest possible energy requirements. This paper discusses the thermal design and considerations of a greenhouse in a microgravity environment (i.e. Martian environment) with extremely low ambient temperature conditions (nearly −200 K) and limited availability of solar radiation (maximum of 590 W/m 2). A parametric study is performed using COMSOL Multiphysics. The effects of varying several design parameters including heater capacity, and placement of heaters are investigated on the indoor thermal condition of the greenhouse. The temperature distribution inside the greenhouse is assessed for several design conditions and the desirable distributions for plant growth are further analyzed. The impact of microgravity conditions is also assessed through a comparison of results between microgravity and normal gravity conditions. The results from this study could be used towards the proper thermal design of greenhouses for the extreme conditions of outer space applications.
Data-Driven Fault Detection in Composite Cylindrical Shells: Directing the Proper Orthogonal Decomposition Prospective Into an Artificial Neural Network Vision
Authors: Liontos Konstantinos N. , Georgiou Ioannis T.
Published: February 2023

This paper presents a vibration data-driven study for damage detection in a physical cylindrical shell made of carbon fiber reinforced polymeric plies. The manufacturing method followed for the synthesis of this structure introduces numerous fault sites as potential initiators of damage propagation. Using three accelerometers, vibration datasets have been collected for damage detection by a classical vibration analysis method based on the change of the curvature of vibration shapes extracted by sectioning-at the value of a dominant natural frequency-the surface-formed landscape of the distribution of the dataset over the processed frequency-space domain. The existence and the position of damage sites in the cylinder are detected by computing the pointwise ratio of the section-based vibration shapes of the datasets. To verify and improve this technique, unleased is the unparalleled data reduction-computational analysis of the advanced proper orthogonal decomposition (POD) transform to detect damage sites as variations of POD modal shapes, being identified as invariants of the motion. The data-driven spirit of POD processing of datasets is conveyed further to support a potential artificial neural networks vision for fault detection by learning aspects of the physical system with training based on the collected datasets.
Experiments on Dynamic Non-Newtonian Fluid Interaction With Shells
Authors: Pellicano Francesco , Zippo Antonio , Iarriccio Giovanni
Published: February 2023

In this work the nonlinear vibrations of a fluid-filled circular cylindrical shell under base excitation is investigated. A polymeric (P.E.T.) thin shell with an aluminum top mass is harmonically excited from the base through an electrodynamic shaker in the neighbourhood of the natural frequency of the first axisymmetric mode. Experiments are carried out both in presence and absence of a contained fluid, which is non-Newtonian (dilatant); the dilatant fluid is composed of a cornstarch-water mixture with 60% cornstarch and 40% water of total weight, it is commonly known as oobleck. The results show a strong non-linear response due to the coupling between the fluid and structure and the shaker-structure interaction that leads to a very interesting dynamic scenario.

The system has been excited in the axial direction (vertical) through a harmonic load, with a stepped-sine sweep controlled output. Tests have been performed on empty shell, fully or partially filled shell with oobleck quiescent fluid.

The dynamic scenario is carefully analyzed by means of time histories, spectra, phase portraits and Poincaré maps. The experiments show the onset of complex dynamics: subharmonic and quasiperiodic responses, Chaos.
Period-3 and Period-6 Motions in a Nonlinear Spring Pendulum
Authors: Guo Yu , Luo Albert C. J.
Published: February 2023

In this paper, symmetric period-3 motions and pairs of asymmetric period-3 and period-6 motions in a periodically excited nonlinear spring pendulum system are determined semi-analytically through the implicit map method. Numerical and analytical results are illustrated for verification. The time histories of displacements and velocities are illustrated for each periodic motions; and the corresponding trajectories in phase plane are also presented.
Modeling and Analysis of Multiple Electrostatic Actuators on the Response of Vibrotactile Haptic Device
Authors: Rajkumar Santosh Mohan , Singh Kumar Vikram , Koo Jeong-Hoi
Published: February 2023

In this research, modeling, and analysis of a beam-type touch screen interface with multiple actuators is considered. A mechanical model of a touch screen system, as thin beams, is developed with embedded electrostatic actuators at different spatial locations. This discrete finite element-based model is developed to compute the analytical and numerical vibrotactile response due to multiple actuators excited with varying frequency and amplitude. The model is tested with spring-damper boundary conditions incorporating sinusoidal excitations in the human haptic range. An analytical solution is proposed to obtain the vibrotactile response of the touch surface for different frequencies of excitations, number of actuators, actuator stiffness, and actuator positions. The effect of the mechanical properties of the touch surface on vibrotactile feedback provided to the user feedback is explored. Investigation of optimal location and number of actuators for a desired localized response, such as the magnitude of acceleration and variation in acceleration response for a desired zone on the interface, is carried out. It has been shown that a wide variety of localizable vibrotactile feedback can be generated on the touch surface using different frequencies of excitations, different actuator stiffness, number of actuators, and actuator positions. Having a mechanical model will facilitate simulation studies capable of incorporating more testing scenarios that may not be feasible to physically test.
Behavior of Myoblasts in Confluent Layer Under Shear Flow Field
Authors: Yonezawa Hiroki , Hashimoto Shigehiro , Kinoshiro Haruki
Published: February 2023

To investigate the effect of shear stress direction on cell orientation, the movement of each cell parallel or perpendicular to the direction of the shear flow field in the two-dimensional confluent layer was investigated in vitro. A Couette-type shear flow between parallel walls was formed between the lower static culture disc and the upper rotating disc. Shear stress (1 Pa) was set by adjusting the rotation speed of the upper disk. After culturing to confluence in a flowless state to adhere myoblasts (C2C12: mouse myoblast line) to the lower disk, shear flow was continuously applied for 7 days in an incubator (incorporated with an inverted phase contrast microscope). The migration of each cell was tracked in the time-lapse images. Experiments have shown that cells migrate along the long axis (not only parallel, but also vertical to the shear stress). This method can be applied to maintain the orientation of muscle cells in the engineered tissue.
Hybrid Parallel Feed Multi-Effect Evaporation Desalination System With Adsorption Cycle
Authors: Al-Khalifah Hassan , Ben-Mansour Rached , Antar Mohamed A.
Published: February 2023

Because thermal based desalination systems are still contributing a substantial share in the desalination industry in the GCC and MENA countries, there is a need to optimize their energy consumption in order to minimize oil consumption. The solution used in this paper is connecting the Multi Effect Desalination (MED) system to an Adsorption cooling (AD) system to improve the performance of existing MED plants. A transient mathematical model is developed to predict the performance of multi-effect parallel feed (MED-PF) evaporation desalination system integrated into an adsorption cooling system to achieve both cooling and potable water production. The study aims at examining the impact of operating conditions on the system performance and comparing the performance of different adsorbent materials (HKUST-1 and silica gel RD-2060) at similar operating conditions. It is found that the integrated system allows lowering the MED last effect temperature below the ambient temperature due to water vapor uptake by AD adsorbent bed. As a result, operational gap increases. Thus, the multi effect desalination system can have more effects within the extended flashing range, resulting in more distillate water production and better recovery of heat input. It is worth mentioning that the number of effects is the most influential parameter in increasing the production of multiple effect desalination systems. Parallel feed layout is selected as a preferred layout of MED systems.

The average distillate water production increases by two to three times compared to the conventional MED cycle. Using the HKUST-1 instead of the silica gel reduces the last effect temperature by 9 °C. This leads to the use of more effects in the MED system compared with using silica gel in the adsorption sub-system.
Investigation on Dispersion Characteristics of Elastic Waves in Steel Strands Based on Floquet Boundary Conditions Method
Authors: Zhang Hongyan , Li Jian , Chen ShiLi , Liu Yang
Published: February 2023

Steel strands have the advantages of good bending performance, strong impact resistance, stable and reliable operation, etc. As a load-bearing structure, the health of steel strands directly affects the stability and safety of the entire structure. Therefore, detecting the damage to in-service steel strands is extremely important. Due to the influence of the helical structure, the contact effect between the wires, and the influence of the applied load, it is difficult to solve the wave problem of the steel strands using the governing equations and boundary conditions from a purely theoretical point of view. The Floquet Boundary Conditions (Floquet BC) method can replace the whole with a single repeatable substructure without rewriting the equilibrium equation, which is more general and simpler than the SAFE method. The advantage of Floquet BC is that only the propagation term is considered, and it is very suitable for irregular waveguides such as steel strands. In this paper, the Floquet BC method is used to analyze the dispersion characteristics of the helical curved rod and the steel strands in the torsional coordinate system, and the results obtained are the same as those obtained by the SAFE method.
Prediction of Electrical Energy Consumption in University Campus Residence Using FCM-Clustered Neuro-Fuzzy Model
Authors: Adeleke Oluwatobi , Jen Tien-Chien
Published: February 2023

Developing a viable data-driven policy for the management of electrical-energy consumption in campus residences is contingent on the proper knowledge of the electricity usage pattern and its predictability. In this study, an adaptive neuro-fuzzy inference systems (ANFIS) was developed to model the electrical energy consumption of students’ residence using the University of Johannesburg, South Africa as a case study. The model was developed based on the environmental conditions vis-à-vis meteorological parameters namely temperature, wind speed, and humidity of the respective days as the input variables while electricity consumption (kWh) was used as the output variable. The fuzzy c-means (FCM) is a type of clustering technique that is preferred owing to its speed boost capacity. The best FCM-clustered ANFIS-model based on a range of 2–10 clusters was selected after evaluating their performance using relevant statistical metrics namely; mean absolute percentage error (MAPE), root mean square error (RMSE), and mean absolute deviation (MAD). FCM-ANFIS with 7 clusters outperformed all other models with the least error and highest accuracy. The RMSE, MAPE, MAD, and R2-values of the best models are 0.043, 0.65, 1.051, and 0.9890 respectively. The developed model will assist in optimizing energy consumption and assist in designing and sizing alternative energy systems for campus residences.
Aerodynamic Analysis of a Car Based on Computational Fluid Dynamics and Machine Learning
Authors: Ma Xingchuan
Published: February 2023

The vehicle’s aerodynamic performance attracts increasing attention because it is critical to its power, fuel economy, and handling stability. Therefore, the aerodynamic analysis is one of the most essential components of car design. To develop new-generation energy-saving cars, this study investigates how the car shapes, especially the angle of the front and back windows, could affect a car’s aerodynamic performance. In particular, a computational fluid dynamics approach combined with a machine-learning algorithm is adopted to investigate the aforementioned problem and determine the optimal designs of a car. In this study, first, ANSYS Fluent is utilized to simulate the turbulent flows over 50 modeled two-dimensional cars with varying angles of front / back windows, followed by a case study on three-dimensional cars. The results show that the car shape could dramatically affect the aerodynamic performance of a car by changing the velocity and pressure fields near the wake region, leading to a reduction of the aerodynamic drag by up to 30%. Finally, using these simulation two-dimensional cars’ results as a training database, a machine learning-based algorithm is developed to predict the drag/lift coefficient quickly and thus find the optimal design.
Effect of Air Gap, Thickness of Polyurethane (PU) Foam, and Perforated Panel on Sound Absorption Coefficient for Acoustic Structures
Authors: Patil Chetan , Ghorpade Ratnakar , Askhedkar Rajesh
Published: February 2023

There are many applications and sectors in today’s era where noise pollution is reaching very high levels. This prolonged noise exposure leads to a detrimental health effect. This may cause loss of concentration, working efficiency, headache, increased blood pressure level, annoyance, and even workplace accidents. Hence, the need to reduce the high noise level is becoming a significant issue. Varieties of absorbing materials are being used in the recent age for noise reduction and sound attenuation. Most of the acoustic enclosures consist of polyurethane foam as a sound absorber. The noise control is achieved by modifying the noise source characteristics, path modification, or muffling at the receiver. The best way to control noise is noise absorption, where acoustic materials are designed to absorb sound. Polyurethane foam is widely accepted because of its good properties like wide absorption frequency range, structural stabilization, low cost, easy handling, and moisture resistance. It has been observed that the sound absorption coefficient (SAC) depends on the thickness of polyurethane foam and the air gap.

This paper discusses the different acoustic properties of various acoustic structures consisting of the perforated panel, air gap, and polyurethane foam for the frequency range of 100–4000 Hz. Different combinations of acoustic structures are proposed to observe the effect of absorptivity in terms of sound attenuation. The effect of layer sequence on the acoustic absorption of the structure has been investigated. The relation between the thickness of the material, air gap, and SAC are also analyzed. FEA can accurately analyze the absorption characteristics at normal incidence of sound-absorbing structure. The acoustic structure consisting of polyurethane foam gives the maximum value of SAC for a frequency range of 2300–4000 Hz. The acoustic structure consisting of the perforated panel, air gap, and polyurethane foam give the maximum SAC value for the lower frequency range of 100 to 2300 Hz.

In the current study, it has been seen that the acoustic structure consisting of polyurethane foam with an air gap gives the minimum value of SAC. The SAC varies with the air gap and thickness of the foam. The study affirmed that using the perforated panels in acoustic structure gives the maximum value of SAC in the lower frequency range. The SAC of a material is calculated with an analytical method and verified with the experimental method and FEA software. For verification of SAC for different acoustic structures, COMSOL Multiphysics 5.5 results are seen to be in good agreement with a maximum difference of 8.1% with that of the experimental results.
A Physics-Based Model of Laser Powder Bed Fusion of NiTi Shape Memory Alloy: Laser Single Track and Melt Pool Dimension Prediction
Authors: Abedi Hossein , Javan Reza , Nematollahi Mohammad Reza , Safaei Keyvan , Al-Gamal Anwar , Elahinia Mohammad , Qattawi Ala
Published: February 2023

NiTi Shape memory alloys are increasingly being employed in a variety of applications, with continuous research into practical processing methods. The laser powder bed fusion (LPBF) manufacturing method is exhibiting increasing attention to fabricating SMA materials due to the high flexibility of controllable process parameters. Finite element method (FEM) approaches are deployed to offer an intelligent fabrication path and minimize the high time and cost expenses of experimentations.

In this work, a thermal model is developed to predict the melt pool size and shape during NiTi’s LPBF. Macroscale physics framework via COMSOL Multiphysics is used to build a thermal model for NiTi LPBF processing. To this end, a single-track scanning of laser over the NiTi substrate with Gaussian power density has been modeled.

The thermal/melt pool modeling of a single laser pass on NiTi substrate is employed. The model is calibrated for the thermal parameters such as the conductive and convective coefficient and emissivity coefficients. The calibration is performed through the comparison of experimental temperature measurements via optical microscopy and in-situ thermal imaging and the numerical modeling results.
Structural Integrity Assessment of the Compensators Used in the Heat Exchangers Under Combined Angular Movement and Lateral Offset
Authors: Sanap Sudarshan B. , Pagar Nitin D.
Published: February 2023

Process industries typically utilize bellows expansion joints (compensators), which offer both axial flexibility and circumferential strength on convolutions. These components are utilized in pipe structures as well as their connections to vital process equipment’s, such as boilers, fixed tube heat exchangers, pressure vessels, pressure relief equipment, pulsation dampeners, etc. The expansion-contraction operation of the compensators attached to the pipes produces different thrusts and stresses, rendering process equipment vulnerable to catastrophic failure if there is an axial misalignment or lateral offset in connection. For the purpose of maintaining structural integrity, it is essential to determine the meridian stresses generated on bellows compensator under various operating conditions. This study examines the quantitative effects of combined lateral shift and angular rotational misalignment on meridional stress levels for the heat exchanger shell bellows. Mainly the generation of the stresses on the U-shaped convolution profile is multifaceted and difficult to evaluate. An experimental setup has been designed to make it easier to see the combined angular rotation and offset at various levels and to improve evaluating the stress levels for analysis purposes. The paper presents the results pertaining to meridional deflection-based stresses. The analysis process signifies the assessment of structural integrity to enable designers to implement mitigating measures regarding the installation of bellows compensators and adequate support conditions.
Understanding Relative Motion Between the Skull and Brain in Shaken Baby Syndrome
Authors: Castrillon Paul , Saboori Parisa , Walker Graham
Published: February 2023

Life of a child is different when they experience shaken baby syndrome (SBS). Severe SBS can lead to a subdural hemorrhage from ruptured bridging veins. There’s plenty of research in the past about the biological aspect of SBS, but there is a lack of research about mechanical forces affecting the child’s head. This study aims to measure the angular displacement between the brain and skull using a Crash Resistant Air Bag Interaction (CRABI) model simulated in Siemens NX. The CRABI head model consists of the skull, arachnoid mater, subarachnoid space, and a hemispherical brain. The trabeculae are modeled as springs and connect the arachnoid mater to the brain to represent a proper motion of the brain within the skull. A displacement is applied to the CRABI torso to represent the caretaker translation force. Results show angular displacement presented in graphs of each case and their distinct oscillations. The cusp shown in each graph represents the angular displacement of the baby’s brain in the anterior or posterior region. This preliminary research helped us understand the mechanical forces of SBS and the reaction of the baby’s head to rotational displacement. The next steps of this study are to determine the rupture of bridging veins.
Inspiratory Muscle Training Improves Maximal Inspiratory Pressure Without Increasing Performance in Elite Swimmers
Authors: Gómez-Albareda Eloi , Viscor Ginés , García Iker
Published: February 2023

Purpose: To analyze the effect of inspiratory muscle training (IMT) on the maximal inspiratory mouth pressure (MIP) and performance of elite swimmers. Methods: Eight participants performed a 3000-m swimming test (T-3000), followed by blood lactate measurements at 1 and 5 minutes postexercise.. The testing protocol was carried out before and after 6 weeks of IMT, in which a high-volume IMT group (HV-IMT) (n = 4) performed IMT twice a day—in the morning in a seated position and in the afternoon in a concurrent session of IMT and core muscle training. Also, a low-volume IMT group (LV-IMT) (n = 4) performed IMT in the morning session only. Results: After the intervention, both groups improved their MIP, HV-IMT (132.75 [27.42] to 156.75 [21.88] cmH2O; P = .010; d = 0.967) and LV-IMT (149.25 [22.82] to 171.50 [23.74] cmH2O; P = .013; d = 0.955), without a significant difference between groups (P = .855). Regarding swimming performance, there were no changes between groups in the T-3000 (P = .472) or lactate removal rate (P = .104). Conclusion: IMT increased inspiratory muscle strength in elite swimmers, but there was no association or meaningful impact on swimming performance.
From scanner to court: A neuroscientifically informed “reasonable person” test of trademark infringement
Authors: Zhang Zhihao , Good Maxwell , Kulikov Vera , van Horen Femke , Bartholomew Mark , Kayser Andrew S. , Hsu Ming
Published: February 2023

Many legal decisions center on the thoughts or perceptions of some idealized group of individuals, referred to variously as the “average person,” “the typical consumer,” or the “reasonable person.” Substantial concerns exist, however, regarding the subjectivity and vulnerability to biases inherent in conventional means of assessing such responses, particularly the use of self-report evidence. Here, we addressed these concerns by complementing self-report evidence with neural data to inform the mental representations in question. Using an example from intellectual property law, we demonstrate that it is possible to construct a parsimonious neural index of visual similarity that can inform the reasonable person test of trademark infringement. Moreover, when aggregated across multiple participants, this index was able to detect experimenter-induced biases in self-report surveys in a sensitive and replicable fashion. Together, these findings potentially broaden the possibilities for neuroscientific data to inform legal decision-making across a range of settings.
Cx26 heterozygous mutations cause hyperacusis-like hearing oversensitivity and increase susceptibility to noise
Authors: Liu Li-Man , Liang Chun , Chen Jin , Fang Shu , Zhao Hong-Bo
Published: February 2023

Gap junction gene
GJB2
(Cx26) mutations cause >50% of nonsyndromic hearing loss. Its recessive hetero-mutation carriers, who have no deafness, occupy ~10 to 20% of the general population. Here, we report an unexpected finding that these heterozygote carriers have hearing oversensitivity, and active cochlear amplification increased. Mouse models show that Cx26 hetero-deletion reduced endocochlear potential generation in the cochlear lateral wall and caused outer hair cell electromotor protein prestin compensatively up-regulated to increase active cochlear amplification and hearing sensitivity. The increase of active cochlear amplification also increased sensitivity to noise; exposure to daily-level noise could cause Cx26
+/−
mice permanent hearing threshold shift, leading to hearing loss. This study demonstrates that Cx26 recessive heterozygous mutations are not “harmless” for hearing as previously considered and can cause hyperacusis-like hearing oversensitivity. The data also indicate that
GJB2
hetero-mutation carriers are vulnerable to noise and should avoid noise exposure in daily life.
Pavlovian-conditioned opioid tolerance
Authors: Farahbakhsh Zahra Z. , Siciliano Cody A.
Published: February 2023

Opioid tolerance develops as a learned response to drug-associated cues and is thus a dynamic effect modulated by the interaction between drug and environment.
Systematic Adaptation of Bacillus licheniformis to 2-Phenylethanol Stress
Authors: Zhan Yangyang , Xu Haixia , Tan Hween Tong , Ho Ying Swan , Yang Dongxiao , Chen Shuwen , Ow Dave Siak-Wei , Lv Xin , Wei Fang , Bi Xuezhi , Chen Shouwen
Published: February 2023

The ability to tolerate organic solvents is essential for bacteria producing these chemicals with high titer, yield, and productivity. As exemplified by 2-PE, bioproduction of 2-PE represents a promising alternative to chemical synthesis and plant extraction approaches, but its toxicity hinders successful large-scale microbial production.
Effect of Austrian COVID-19 lockdowns on acute myocardial infarction frequency and long-term mortality: a multicentre observational study
Authors: Mousavi Roya Anahita , Roth Dominik , Wallmüller Christian , Pichler Gernot , Stratil Peter , Schreiber Wolfgang , Delle-Karth Georg , Schober Andreas
Published: February 2023

Objectives

The aim of this study was to find out if the decrease in acute myocardial infarction (AMI) admissions during the first COVID-19 lockdowns (LD), which was described by previous studies, occurred equally in all LD periods (LD1, LD2, LD2021), which had identical restrictions. Further, we wanted to analyse if the decrease of AMI admission had any association with the 1-year mortality rate.

Design and setting

This study is a prospective observational study of two centres that are participating in the Vienna ST-elevation myocardial infarction network.

Participants

A total of 1732 patients who presented with AMI according to the 4th universal definition of myocardial infarction in 2019, 2020 and the LD period of 2021 were included in our study. Patients with myocardial infarction with non-obstructive coronary arteries were excluded from our study.

Main outcome measures

The primary outcome of this study was the frequency of AMI during the LD periods and the all-cause and cardiac-cause 1-year mortality rate of 2019 (pre-COVID-19) and 2020.

Results

Out of 1732 patients, 70% (n=1205) were male and median age was 64 years. There was a decrease in AMI admissions of 55% in LD1, 28% in LD2 and 17% in LD2021 compared with 2019.

There were no differences in all-cause 1-year mortality between the year 2019 (11%; n=110) and 2020 (11%; n=79; p=0.92) or death by cardiac causes [10% (n=97) 2019 vs 10% (n=71) 2020; p=0.983].

Conclusion

All LDs showed a decrease in AMI admissions, though not to the same extent, even though the regulatory measures were equal. Admission in an LD period was not associated with cardiac or all-cause 1-year mortality rate in AMI patients in our study.
Dietary sodium, potassium intake, sodium-to-potassium ratio and risk of hypertension: a protocol for systematic review and dose–response meta-analysis of cohort studies
Authors: Yang Yingtian , Wu Qian , Lv Qianyu , Li Junjia , Li Lanlan , Wang Shihan
Published: February 2023

Introduction

Hypertension (HTN) is the leading cause of disease and death on a global scale. Diet’s sodium and potassium levels may synergistically affect blood pressure. Currently, the sodium-to-potassium (Na/K) ratio is becoming a more reliable indicator. There has not been a systematic investigation of the dose–response relationship between dietary sodium, potassium, the Na/K ratio and the incidence of HTN based on the same study criteria. This study will conduct a thorough dose–response meta-analysis of cohort studies to estimate the effects of dietary sodium, potassium, and the Na/K ratio on the incidence of HTN to provide the most accurate reference for sodium and potassium intake.

Methods and analysis

We will identify all relevant prospective and retrospective cohort studies by searching PubMed, Embase and Web of Science (from inception until December 2022). Exposures are 24 hours urinary excretions, and the outcome is the incidence of HTN. Two researchers will perform the literature selection and data extraction separately. The Newcastle-Ottawa Scale will be used to evaluate the quality of the included studies. We will use both linear and non-linear regression models to investigate the dose–response relationship among different levels (≥3) of sodium, potassium, Na/K ratio intake and the incidence of HTN (OR/RR/HR). Subgroup and sensitivity analyses will be applied to assess the potential heterogeneity sources and examine the stability of the results. We will also evaluate heterogeneity across studies and publication bias. Stata V.15.0 and RevMan V.5.0 will be used for statistical analyses.

Ethics and dissemination

According to the Institutional Review Board/Independent Ethics Committee of the Guang'anmen Hospital of the China Academy of Chinese Medical Science, this systematic meta-analysis protocol does not require ethical approval or informed consent. This meta-analysis will be published in a scientific journal with peer reviews.

PROSPERO registration number

CRD42022331203.
Driving communication forward: improving communication for palliative care patients around driving and opioids – a quality improvement report
Authors: Ismail-Callaghan Seline , Howarth Megan , Allan Rebecca , Davey Nicola , Meddick-Dyson Stephanie Amanda
Published: February 2023

Introduction

The number of people requiring palliative care is increasing with an ageing comorbid population. Pain is a prevalent symptom for palliative care patients and is often managed with opioids. Opioids reduce reaction time and can cause drowsiness and visual disturbance. Evidence recommends that driving should be avoided until a stable dose of opioids has been reached. It is vital for patient and public safety that these facts are communicated to patients who are prescribed opioids, as well as the legal consequences if guidance is not followed. These discussions facilitate joint decisions, optimising patient freedom and quality of life. Surprisingly though these important discussions around driving and opioids do not always occur, and so this project sought to develop a systematic approach to integrating them into practice.

Design

Retrospective case note analysis and prospective interventional quality improvement study.

Setting

A 16 bedded specialist palliative care inpatient unit.

Population

Hospice inpatients with an Eastern Council Oncology Group performance score of 0–3 who had been prescribed opioids.

Intervention

Three plan–do–study–act cycles were performed. First, the issue was discussed in the daily multidisciplinary team meeting to raise awareness, second a prompt was added to a pre-existing clerking proforma. Finally, a reminder poster was placed in the ward office to promote discussion prior to discharge.

Outcome measures

Primary measures were the proportion of patients with the presence of documented driving status, and the presence of a documented discussion surrounding driving and opioids.

Results

Baseline data found that 11.5% of patients had a documented driving status and 11.5% had a documented discussion surrounding driving and opioids. Over the course of the study, the proportion improved to 65.2% and 60.9%, respectively.

Conclusion

Use of quality improvement change methods have resulted in the successful integration of new interventions to increase discussions around driving when prescribed opioids. A previously overlooked issue in this facility, thus improving clinical and patient information sharing, and patient empowerment to take charge of their own health.