bluuebunny/crossref_metadata_2025 huggingface dataset:
Design, Prototyping, and Experiments Using Small-Scale Helical Drive Rover for Multi-Terrain Exploration
Authors: Vadlamannati Ashwin , Beknalkar Sumedh , Best Dustin , Bryant Matthew , Mazzoleni Andre
Published: February 2024

Rovers designed for polar exploration primarily operate in flat and arid central plateau of the Antarctic and are unsuitable for multi-terrain operation such as slushy slow, wet soil, open ice and open ocean. The Multi-terrain Amphibious ARCtic explOrer or MAARCO rover is a design concept that employs a pair of helical drives in order to traverse the diverse landscape of the Arctic for autonomous research missions. A small-scale prototype (3:10 scale) of the MAARCO rover was developed to test terrestrial motion. The prototype is a screw-propelled vehicle that has two helical drives (similar to Archimedes’ screw) actuated by two independent motors to employ a differential steering system.

The prototype performed several different maneuvers on a dry and wet sand — moving in a straight line, turning left, and turning right, and moving sideways by controlling the rotational speeds of the two drives. The sensors on the prototype collect data on angular orientation, linear acceleration and motor rotations.

Through the tests the rover provided critical insight into the dynamics of the MAARCO rover, particularly, the effect of substrate failure or non-failure on the linear displacement of the rover. Further testing on different substrates and of the rover design on inclines surfaces will provide the MAARCO team valuable insight into designing a full-scale rover design.
A Study on the Effect of Fiber Orientation on the Strength and Failure of 3D-Printed Carbon Fiber Reinforced Polymers
Authors: Kokner Yesim , Delpierre Arthur , Couzis Jason P. , Ardebili Mahmoud , Delale Feridun
Published: February 2024

The potential of 3D printed carbon composites as a material for advanced engineering applications was investigated by fabricating and testing of carbon fiber-reinforced composites using 3D printing technique. Three carbon fiber layups and a pure polymer were investigated. In the first configuration, the fibers were parallel to the direction of applied stress (0° orientation). In the second configuration, the fibers were perpendicular to the stress (90° orientation). In the third configuration, the fibers were orientated in diagonal pattern (± 45° orientation). The geometry of the test specimen was based ASTM D3039 protocol for testing composite materials. Compositional results indicated that the continuous carbon fiber filament used in the printer was composed of 39% carbon fibers. The specimens contained between 22–24% carbon fibers. Axial testing results indicated that the 90° fiber oriented specimen was the weakest, comparable or slightly weaker than the pure matrix specimen. The ±45° orientation of fiber improved the strength by a factor 3.5. The 0° oriented fiber reinforcement increased strength by a factor of 4 folds compared to ±45° orientation and about 22 folds compared to pure matrix or 90° orientation. The failure in the pure matrix, 90° and ±45° specimen occurred with clean fracture pattern in gauge section. The 0° sample failure occurred very close to the end taps portion with a great deal of delamination. The failure pattern for this configuration has led us to believe that its strength is even higher than that observed in the testing.
Verification Process for Finite Element Modelling Technique Used in Biological Hard Tissue
Authors: Townsend Molly T. , Mills Matthew , Sarigul-Klijn Nesrin
Published: February 2024

An approach is presented for calculation verification of geometry-based and voxel-based finite element modelling techniques used for biological hard tissue. The purpose of this study is to offer a controlled comparison of geometry- and voxel-based finite element modelling in terms of the convergence (i.e., discretization based on mesh size and/or element order), accuracy, and computational speed in modelling biological hard tissues. All of the geometry-based numerical test models have hp-converged at an acceptable mesh seed length of 0.6mm, while not all voxel-based models exhibited convergence and no voxel models p-converged. Converged geometry-based meshes were found to offer accurate solutions of the deformed model shape and equivalent vertebral stiffness, while voxel-based models were 6.35%±0.84% less stiff (p < 0.0001) and deformed 6.79%±0.96% more (p < 0.0001). Based on the controlled verification study results, the voxel-based models must be confirmed with local values and validation of quantities of interest to ensure accurate finite element model predictions.
Control Strategy of Compressor Surge for Dual Stack Fuel Cell by Model Based Design
Authors: Choi Yoora , Han Jaesu , Yu Sangseok
Published: February 2024

Proton Exchange Membrane Fuel Cell is drawing attention as a next-generation eco-friendly system that does not emit exhaust gas. Since hydrogen vehicle requires frequent load fluctuations, the peripheral devices also require rapid response against rapid changes. The heavy dynamics of the compressor greatly result in a compressor surge that causes rapid perturbation between the discharge flow rate and pressure in the air supply system.

This study aims to design a compressor’s operation layout in a 200kW class dual-stack. To this end, a stack model that can analyze the vehicle dynamics model, including the components constituting the air supply system and thermal management system, was developed. In addition, the compressor contains a surge control loop to adjust the oxygen supply rate through a valve or motor speed control in the event of an arrest. The fuel cell and air supply system model was developed using MATLAB/Simulink®, and the output of the fuel cell and the power consumption of the air supply system were derived according to the input required power. Through this, the operation efficiency according to the operation method was analyzed, and the required power achievement level was analyzed to select the optimal operation logic.
Numerical Investigation of an Ocean Brick System
Authors: Bollineni Hari , Wang Xiuling
Published: February 2024

A 3-D CFD simulation of an ocean brick system situated in a wave tank is presented in this study. An ocean brick system is a type of ocean engineering structure that is designed to withstand the forces of waves and currents to reduce erosion of the shoreline in coastal areas. The study uses a Finite Volume Method (FVM) to solve Naiver-Stokes equations using a commercial CFD solver ANSYS/FLUENT. A user defined function is used to generate waves similar to that of the experiment within the simulation. The generated wave validated by a theoretical approach. The impact of ocean bricks on the tidal waves to reduce the intensity of the wave and the pressure exerted on the ocean bricks by the wave is studied. The proposed simulation is then validated using experimental data of ocean bricks in a wave tank system.
Next-Generation Automation: Development and Simulation of an Autonomous Sorting System
Authors: Koe Francisco , Guerra-Zubiaga David A. , Perry Lashaundra , Chauhan Vedang D. , Gonzalez-Badillo Germanico
Published: February 2024

The new 4.0 industrial revolution has changed the way that products are manufactured and processed in many ways. One of these ways is using different Digital Manufacturing (DM) tools. These tools have a variety of uses and ways that they can improve manufacturing at every level; one of these tools being digital twin creation. This paper attempts to utilize key Industry 4.0 trends in optimizing a manufacturing process in which a robotic arm is in a pick-and-place operation. The goal of this research is to propose a solution by the Digital twin’s concept incorporating some industry 4.0 trends. A digital manufacturing model implemented with Tecnomatix is created to leverage digital technologies to support the manufacturing operations digital twin and to improve upon the existing system to facilitate the foundation for growth as well as cost control, scheduling, and quality management. These digital models allow the integration of intelligent sensors and a standardized IIoT framework helped to evaluate the efficiency of the system. This paper aims to implement a FANUC robot modeled in Tecnomatix incorporating an Intelligent Automation (IA) process that adheres to Industry 4.0 standards.
Study of Phase Change Materials for Heat Dissipation of Systems With Transient Heat Generation
Authors: Trulson Ethan , Carbajal Gerardo , Park Younggil , Romero-Ramirez Edwar , Nees Alexander
Published: February 2024

An experimental study evaluated the performance of the phase change materials (PCM) cooling method for systems with transient heat generation. A customized cylindrical heating system was implemented to vary the amount of heat generation. The study was conducted under transient and steady-state conditions for different heat generations. The experimental results indicate an improvement in the PCM cooling system compared with the traditional air-cooling system. In the present study, a cylindrical sample was placed in the cooling system, initially cooled only by air and later by PCM. A data acquisition system measured the readings from several thermocouples installed in the sample to determine the temperature response of the sample. A total of nine thermocouples were installed, three on the surface of the sample, three five millimeters inside the sample, and three in the PCM-metal foam. Temperature readings from the PCM-metal foam closely monitored the melting process. To improve the performance of the PCM, aluminum fins were installed around the PCM. The fin dissipates the energy stored by the PCM and helps to dissipate its internal energy to the surroundings. The experimental study revealed a significant increase in the PCM-air aluminum fin cooling system compared to the traditional air-cooling system.
Using Electrical Resistance As a Diagnostic During Process-Structure-Property Investigation of CNT Forests
Authors: Surya Ramakrishna , Maschmann Matthew R.
Published: February 2024

Controlling the self-assembly of carbon nanotube (CNT) forests is important for tailoring their ensemble properties for specific applications. In this study, real-time electrical resistance measurements of in-situ CNT forest syntheses was established as a method to interrogate the evolution of CNT forest morphology. The method employs in-situ scanning electron microscopy (SEM) synthesis techniques to correlate observed morphological changes to electrical resistance. A finite-element simulation was used to simulate CNT forest synthesis and the evolution of electrical resistance in a configuration like that used experimentally. The simulation considers the contribution of CNT electrical resistance, CNT-CNT junction resistance, and CNT-electrode contact resistance. Simulation results indicate that an increased number of CNT-CNT junctions with time have a diminishing effect on increasing electrical conductance. Experimentally observed increases in electrical resistance are attributed to increasing CNT delamination from the electrical contacts.
Deterministic Methods for Verification, Validation, and Uncertainty Quantification in Engineering Code Applications
Authors: Kemper Bart , Williams Kaylie
Published: February 2024

Simulation credibility relies upon Verification, Validation, and Uncertainty Quantification (VVUQ) techniques. VVUQ methods check the simulation code, the modeling system, the assumptions used and examines how much uncertainty is associated with various stages of the development. This, in turn, gives the program managers and design leaders the information needed to make informed, ethical decisions on how to carry out the design and testing. Arguably, this should be used with any engineering simulation. The challenge is the various VVUQ methods are rooted in engineering domains of high uncertainty and high risk, such as space flight, medical devices, and nuclear power. These designs are “nondeterministic,” or have no design codes that establishes safe limits in design by analysis. In traditional engineering, VVUQ is not needed because the work is done in a well understood area. Uncertainty has been addressed with the use of well-known practices and established design margins. This paper offers a “deterministic VVUQ” method intended for situations where simulation methods like Finite Element Method are used within the bounds of an overarching design code. This will provide a measure of quality control to the simulations without the expense and time of a full nondeterministic VVUQ process.
A Unified Process Damping Model in Cutting With Velocity and Ploughing Effects
Authors: Jiang Yan-Ru , Zhang Xiao-Jian
Published: February 2024

The process damping is the theoretical explanation for the stability improvement at low spindle speed cutting. The two main sources of the process damping are velocity-dependent effect and ploughing-indentation effect. In most existing studies, only ploughing-indentation effect is considered to establish a process damping model for simplified calculation. The influence of velocity-dependent effect on stability is less studied. Therefore, this study aims to establish a unified process damping model in milling considering both velocity-dependent effect and ploughing-indentation effect to predict the stability. The velocity-dependent effects in up milling and down milling are investigated by the energy dissipation. Results show that this effect provides a negative process damping in up milling at low-speed and low radial immersion, but improves the stability in down milling. However, the ploughing-indentation effect always damps chatter and improves stability regardless of milling form. To further research the weight of two effects, the ratio of velocity-dependent to ploughing-indentation effects is proposed. When the ratio is larger than 1, the velocity-dependent effect plays a more significant role in stability improvement than the ploughing-indentation effect. The predicted stability lobe diagram based on the unified model is verified by previous experiments.
Assessing the Lubrication Performance of Sunflower Oil Modified With Montmorillonite Clay (MMT) Nanoparticles for Industrial Applications
Authors: Rahman Md Mashfiqur , Biswas Md Abu Sayeed , Peña-Parás Laura , Maldonado-Cortés Demófilo , Ortega Javier A.
Published: February 2024

Because of the environmental impact and price volatility, there has been a growing concern about using petroleum-based lubricants. This issue has encouraged research into the development of biodegradable lubricants like vegetable oils. This study assessed the tribological behavior of sunflower oil modified with Montmorillonite nanoclay (MMT) as lubricant additives. A block-on-ring tribometer was used to assess the wear and friction characteristics of the nano-lubricants. A custom-made tapping torque tester was used to evaluate the nano-lubricants in a real-world application. It was found that the volumetric wear, Coefficient of Friction, and torque of the system decreased when MMT nanoparticles were added. The experimental results indicated that sunflower oil modified with 2.0 wt.% MMT exhibited the best tribological behavior, reducing COF and wear volume loss by 88% and 63%, respectively. Based on the results, the newly developed sunflower oil-based nano-lubricants, with the addition of MMT nanoclay, could be a promising environmentally friendly solution to compete with petroleum-based lubricants.
Calibration of the K-ω SST Turbulence Model for Backward Facing Step Problem Using Multi-Objective Optimization
Authors: Yildizeli Alperen , Cadirci Sertac
Published: February 2024

Flow over a Backward Facing Step (BFS) is a classic fluid dynamics problem that has received considerable attention in the research community. In this study, the k-ω SST turbulence model is calibrated using ANSYS Fluent flow solver based on the comparison with Direct Numerical Simulation (DNS) data of a flow over a BFS which is available in the literature. On at a time (OAT) sensitivity analysis is conducted to determine six most dominant turbulence closure coefficients. Skin friction coefficient distribution is examined as quantity of interest. After determining the six most effective parameters, a deep neural network is trained with 500 CFD simulations; and multi-objective genetic algorithm is applied to reduce both RMSE and maximum absolute error of the skin friction coefficient distribution. The results of the study demonstrate that the model coefficients were successfully calibrated using multi-objective optimization. Improvements of the velocity profiles and skin friction coefficient are addressed to the optimization of closure coefficients which are related to the diffusion and production terms of turbulence model of interest. Optimum values of α∞*, β∞*, βi,1, βi,2, a1, and σω,2 were found 13.5% higher, 25% lower, 6.5 % lower, 6.5% higher, 14.5% higher and 3% higher than their original values, respectively.
Characterizing the Effect of Post Weld Heat Treatment on the Mechanical Properties of Laser Beam Welded Additive Manufactured Ti6Al4V
Authors: Akinlabi Esther T. , Omoniyi Peter , Jen Tien-Chien , Mahamood Rasheedat M. , Mwema Frederick , Akinlabi Stephen A. , Abima Cynthia S.
Published: February 2024

The Ti6Al4V alloys are finding various industrial applications due to their attractive attributes, which can be enhanced via heat-treatment processes. In this study, titanium sheets (Ti6Al4V) were manufactured through laser metal deposition (LMD) using Ti6Al4V powder of particle sizes between 45–90 μm. The build parameters used are optimized at a laser power of 400 W, powder feed rate of 2.4 g/min, hatch spacing of 0.9652 mm, and scanning rotated at 90° between successive layers. The built block is sliced using a wire-electric discharge machine (EDM) into sheets of 2 mm thickness. The resulting blocks were joined using the butt configuration through laser beam welding technology. Post-weld heat treatments were conducted on the welds above the β transus temperature of 995°C. Material characterizations of the evolving properties were conducted using Optical Microscopy, Vickers microhardness, and tensile testing. The investigations show that the heat-treated samples have enhanced properties and can be recommended. The outcome of this research is significant as it gives insight into the optimization of laser welding and post-weld heat treatment parameters of Titanium Alloy Grade 5 for industrial applications.
Solving Flows Across Rotor and Stator Cascades With Local Neural Operator for Computational Fluid Dynamics
Authors: Ye Ximeng , Li Hongyu , Qin Guoliang
Published: February 2024

This work presents a practical application of local neural operator (LNO) in computational fluid dynamics (CFD), which is a promising newly proposed deep learning based numerical solver for transient partial differential equations. Here, LNO is trained to learn the intrinsic law behind compressible Navier-Stokes equations and then solve arbitrary unseen flows by collaborating with specifically designed boundary treatment. With LNO as a CFD method, we investigate the unsteady flow across cascades of airfoils in turbomachinery. According to the results, LNO correctly and efficiently captures the fluctuations of velocity fields due to the interaction between the rotor and stator. The mean square error for velocity is below 0.082 and the computation is ×169 faster than conventional finite element method. We further conduct a brief investigation on several cases with different arrangements of cascades. These practices show great flexibility of LNO in tasks with complex geometries, diverse boundaries, and delicate flow patterns, indicating great potential for applications in various scientific research and engineering.
Investigating the Material Flow and Thermal Distribution in a Hybrid Additive Manufacturing Incremental Forming (HAMIF) Technology
Authors: Tiwari Mithilesh Kumar , Gupta Ankit Kumar , Shahare Harshal Y. , Ponappa K. , Tandon Puneet
Published: February 2024

The combination of Additive Manufacturing (AM) and Incremental Forming (IF) technologies has numerous advantages, including the ability to manufacture intricate components, reduce production complexity, enable customization, improve resource efficiency, and reduce material waste. Hybrid manufacturing processes that integrate both technologies can address many of the disadvantages of each technology, leading to higher productivity and sustainability. The coalescence of metal additive manufacturing and incremental forming involves the deposition of subsequent layers of raw material on a platform through additive manufacturing, followed by forming these deposited layers through incremental forming. This paper investigates the design and fine-tuning of this innovative approach. Furthermore, the numerical simulations are shown whose results suggest that Hybrid Additive Manufacturing Incremental Forming (HAMIF) has the potential to revolutionize the advanced manufacturing industry. The HAMIF setup includes supporting plates, fastening devices, a hopper-barrel assembly, band heaters, a nozzle, and a spindle for incremental forming. The hybrid extrusion forming unit involves a screw with varying pitch and a detachable forming tip, and a solenoid setup regulates the up and down movement of the hopper-barrel assembly for the simultaneous operation of AM and IF processes. The paper discusses key aspects related to the hybrid extrusion forming unit, including the material flow inside the hopper barrel assembly, thermal distribution, and forming forces. Numerical simulations using COMSOL Multiphysics are used to model the flow of material within the extrusion forming unit and determine the proper choice of material for the hybrid extrusion forming unit. The HAMIF technology can lead to greater efficiency, sustainability, and flexibility in the manufacturing industry.
Input-Output Linearization Control of 1 DOF Electromagnetic Transducer
Authors: Tsakyridis Georgios , Xiros Nikolaos I.
Published: February 2024

The non-linear dynamics of a linear mechanical oscillator coupled with an electromagnet and its driving circuit through a magnetic field are investigated. Input-Output Feedback Linearization is a used to transform the non-linear system into a linear system that is easier to control. The approach involves canceling out the non-linear terms in the system equations by introducing an appropriate input-output mapping. This mapping transforms the system into a set of linear equations, which can then be controlled using traditional linear control methods. A controller using a pole placement is implemented to stabilize the electromechanical oscillator and track a reference trajectory. This way we can demonstrate that the electro-magneto-mechanical transducer is suitable for sensor applications by enabling precise and rapid tracking of state variables. Moreover, the potential to drive multiple modules from a single source using modulation further highlights the applicability of this technology in various engineering applications, including robotics, aerospace, and power systems.
Research on Health Monitoring and Prediction Technology for Civil Aircraft Environmental Control Systems: A Review
Authors: Zhao Jin , Ma Cunbao , She Zhiyu
Published: February 2024

The Aircraft Environmental Control System (AECS) provides a safe and comfortable environment for passengers by adjusting environmental parameters such as temperature and humidity in the cabin. It also provides cooling air to the aircraft electronic equipment compartment to prevent the electronic devices from overheating. AECS failures can lead to passenger discomfort and even trigger serious flight accidents such as emergency descent. Therefore, the aviation industry is currently actively conducting research on AECS health monitoring and predictive technologies to assist with AECS maintenance. This article reviews the methods of AECS health monitoring and prediction. First, various health monitoring and prediction methods are classified based on existing literature, and the research progress of model-based and data-driven methods are respectively described. Secondly, the advantages and disadvantages of various methods are compared and analyzed. The research results show that: (1) compared with data-driven methods, model-based methods can obtain more accurate monitoring and prediction results, but due to the difficulty in modeling, researchers often only conduct relevant research on AECS subsystems or individual components; (2) data-driven methods are more popular among researchers because of their simplicity. With the continuous development of artificial intelligence technology, data-driven methods have also shown more robust development potential. Finally, combined with the design of multi-electric AECS, the future development direction of AECS health monitoring and prediction technology is discussed, and suggestions are proposed.
Modernizing Engineering Education in 2023: Minimizing Academic Honesty Policies, Treating Grades As Measurements, Individualizing Educational Experiences and Incorporating More Project-Based Learning to Better Bridge the Gap Between High School and Career
Authors: Nedyalkov Ivaylo
Published: February 2024

In 2023, engineering education is facing a wide range of challenges, and yet multiple opportunities are underutilized. Students often use online resources, including YouTube videos, and sites like Chegg. Academic honesty policies are not strictly enforced, and even when enforced, they are successfully implemented only for a fraction of the students who violate those policies. The advancement of AI tools like ChatGPT is making it even more challenging to detect if a student has used such tools or other resources that are not typically allowed in classes. Grade inflation, inaccuracy, and inconsistency are another concern. Some engineering education experiences are becoming outdated. COVID-19 and its aftermath are posing additional challenges. Student and faculty fatigue and burnout have a negative impact on learning outcomes and mental health.

The author proposes a few major changes in engineering education in an attempt to address these challenges and bring the focus back to bridging the gap between high school and career. The changes include minimizing the use of academic honesty policies; integrating contemporary tools like AI; modifying grading to focus on evaluating understanding and treating grades as measurements with uncertainties; and implementing a more holistic approach to engineering education by better incorporating student group experiences, hands-on engineering activities in maker spaces, better use of curated video/online resources, and optional assignments.

With the proposed changes, the author hopes that engineering education in this decade will re-focus on student success and well-being and decrease the workload for both students and faculty, while improving the learning outcomes.
Operational Modal Analysis and Baseline-Free Damage Detection of a Beam Under Random Excitation via a Novel Demodulation Method With a Reference Signal
Authors: Lyu Linfeng , Yuan Ke , Zhu Weidong
Published: February 2024

A novel demodulation method with a reference signal is developed for operational model analysis of a beam structure under a random excitation. The novel demodulation method can process measurements of the beam by a continuously scanning laser Doppler vibrometer (CSLDV) system and measurements of a reference point on the beam by a single-point laser Doppler vibrometer to estimate its modal parameters, such as damped natural frequencies and undamped mode shapes. Damped natural frequencies of the beam are estimated from fast Fourier transforms of measurements of the CSLDV system. A cross-correlation function between a measurement of the CSLDV system and a measurement of a single-point laser Doppler vibrometer is calculated, and the cross-correlation function is multiplied by a sinusoidal signal whose frequency is one estimated damped natural frequency of the beam. The processed cross-correlation function is filtered by a low-pass filter to obtain the undamped mode shape of the beam that corresponds to the damped natural frequency of the beam. Smooth polynomials are used to fit estimated undamped mode shapes, which can be considered as undamped mode shapes of an undamaged beam. Curvatures of estimated undamped mode shapes and polynomials are compared by curvature damage indices to determine the location of a damage in the beam. The novel demodulation method is investigated by measurements from both finite element simulation and experiment. Modal parameters of a finite element damaged beam model and a damaged beam specimen, which are under random excitation, are successfully estimated, and locations of damages in the beam model and beam specimen are accurately determined. The novel demodulation method with a reference signal can be used for damage detection of a beam structure under random excitation, while a traditional demodulation method can be only used for damage detection of a beam structure under sinusoidal excitation.
On the Prediction of Fuel Consumption for Dual-Fuel Low-Speed Marine Engines
Authors: Rempel da Silva Amanda , França Gean Carlos , Ordonez Juan Carlos , Hood Marques Crístofer
Published: February 2024

The International Maritime Organization has been concerned with the pollution from ships and has enforced regulations to reduce greenhouse gas emissions. In this context, specific fuel consumption is a crucial parameter to select the most efficient and environmentally friendly engine. This parameter can be obtained by means of simulation models with various levels of sophistication, which can be either coded in basic programming languages or run in dedicated packages. The aim of the present study is to conceive a simplified model to predict the specific fuel consumption of low-speed dual-fuel engines with low-pressure gas injection driving either fixed or controllable pitch propellers. Clear specific fuel consumption trends were revealed when a normalization process was employed and then polynomials were obtained by numerical regression. This model requires very limited input data to predict the specific fuel consumption of an engine at any contractual maximum continuous rating, including part load operation. Results showed very close qualitative behavior and the highest deviations occurred for the brake-specific pilot consumption, peaking at about 5%. At last, the developed approach was concluded to be an easy-to-implement and fast-to-run model with promising usage for optimization studies.
Investigation of Nanofin Effect (nFE) for Investigating the Anomalous Properties of Nanofluids
Authors: Bhattacharya Ritwik , Shettigar Nandan , Thyagarajan Ashok , Shafiee Shahin , Banerjee Debjyoti
Published: February 2024

In this study, oleo-nanofluids containing casein (protein nanoparticles) in paraffin oil (which is also a phase change material) were synthesized and the density of the extracted nanofluids was measured using the Archimedean principle of buoyancy. Control experiments were performed to ascertain the long-term stability of the colloidal suspensions by introducing minute variations in the synthesis protocol. The experimental results show an overall enhancement of 13.79% in density compared to the neat solvent. Furthermore, the colloidal density deviates by 6.45% from the values predicted by the conventional mixture rule. This unusual phenomenon of “deviant” or surplus density can be attributed to the formation of a semi-crystalline compressed phase in the non-aqueous fluid domain. The experimental data reported in the present study will be used in the design of experiments for investigating the influence of the “nanofin effect” (nFE) upon the density deviation observed in oleo-nanofluids.
Simulation and Modeling for the Vaporization of a Freely Moving Drop at Moderate Weber Numbers
Authors: Boyd Bradley , Becker Sid , Ling Yue
Published: February 2024

The vaporization of a freely moving liquid droplet in a uniform high-temperature gas stream is investigated through direct numerical simulation. The sharp liquid-gas interface is tracked using the geometric Volume-of-Fluid (VOF) method. The incompressible Navier-Stokes equations are solved in conjunction with a two-fluid model for thermal energy advection and conduction, with an immersed Dirichlet boundary condition at the interface to implicitly account for latent heat absorption. The model is implemented in the open-source solver Basilisk, which uses adaptive quadtree/octree mesh for spatial discretization and allows for adaptive mesh refinement of the region near the interface. Simulations of an acetone droplet at moderate Weber numbers are conducted, where the droplet morphology evolution varies from vibrational to bag breakup modes. We observe an increase in the vaporization rate of the droplet as it deforms, and a strong correlation between the windward surface area of the droplet and the vaporization rate is found.
Evolutionary history influences the microbiomes of a female symbiotic reproductive organ in cephalopods
Authors: Vijayan Nidhi , McAnulty Sarah J. , Sanchez Gustavo , Jolly Jeffrey , Ikeda Yuzuru , Nishiguchi Michele K. , Réveillac Elodie , Gestal Camino , Spady Blake L. , Li Diana H. , Burford Benjamin P. , Kerwin Allison H. , Nyholm Spencer V.
Published: February 2024

Many female squids and cuttlefishes have a symbiotic reproductive organ called the accessory nidamental gland (ANG) that hosts a bacterial consortium involved with egg defense against pathogens and fouling organisms. While the ANG is found in multiple cephalopod families, little is known about the global microbial diversity of these ANG bacterial symbionts. We used 16S rRNA gene community analysis to characterize the ANG microbiome from different cephalopod species and assess the relationship between host and symbiont phylogenies. The ANG microbiome of 11 species of cephalopods from four families (superorder: Decapodiformes) that span seven geographic locations was characterized. Bacteria of class
Alphaproteobacteria, Gammaproteobacteria
, and
Flavobacteriia
were found in all species, yet analysis of amplicon sequence variants by multiple distance metrics revealed a significant difference between ANG microbiomes of cephalopod families (weighted/unweighted UniFrac, Bray–Curtis,
P
= 0.001). Despite being collected from widely disparate geographic locations, members of the family Sepiolidae (bobtail squid) shared many bacterial taxa including (~50%)
Opitutae
(Verrucomicrobia) and
Ruegeria
(Alphaproteobacteria) species. Furthermore, we tested for phylosymbiosis and found a positive correlation between host phylogenetic distance and bacterial community dissimilarity (Mantel test
r
= 0.7). These data suggest that closely related sepiolids select for distinct symbionts from similar bacterial taxa. Overall, the ANGs of different cephalopod species harbor distinct microbiomes and thus offer a diverse symbiont community to explore antimicrobial activity and other functional roles in host fitness.

IMPORTANCE

Many aquatic organisms recruit microbial symbionts from the environment that provide a variety of functions, including defense from pathogens. Some female cephalopods (squids, bobtail squids, and cuttlefish) have a reproductive organ called the accessory nidamental gland (ANG) that contains a bacterial consortium that protects eggs from pathogens. Despite the wide distribution of these cephalopods, whether they share similar microbiomes is unknown. Here, we studied the microbial diversity of the ANG in 11 species of cephalopods distributed over a broad geographic range and representing 15–120 million years of host divergence. The ANG microbiomes shared some bacterial taxa, but each cephalopod species had unique symbiotic members. Additionally, analysis of host–symbiont phylogenies suggests that the evolutionary histories of the partners have been important in shaping the ANG microbiome. This study advances our knowledge of cephalopod–bacteria relationships and provides a foundation to explore defensive symbionts in other systems.
Class A capsid assembly modulator apoptotic elimination of hepatocytes with high HBV core antigen level
in vivo
is dependent on
de novo
core protein translation
Authors: Berke Jan Martin , Tan Ying , Sauviller Sarah , Wu Dai-tze , Zhang Ke , Conceição-Neto Nádia , Blázquez Moreno Alfonso , Kong Desheng , Kukolj George , Li Chris , Zhu Ren , Nájera Isabel , Pauwels Frederik
Published: February 2024

Capsid assembly is critical in the hepatitis B virus (HBV) life cycle, mediated by the viral core protein. Capsid assembly is the target for new anti-viral therapeutics known as capsid assembly modulators (CAMs) of which the CAM-aberrant (CAM-A) class induces aberrant shaped core protein structures and leads to hepatocyte cell death. This study aimed to identify the mechanism of action of CAM-A modulators leading to HBV-infected hepatocyte elimination where CAM-A-mediated hepatitis B surface antigen (HBsAg) reduction was evaluated in a stable HBV replicating cell line and in AAV-HBV-transduced C57BL/6, C57BL/6 SCID, and HBV-infected chimeric mice with humanized livers. Results showed that
in vivo
treatment with CAM-A modulators induced pronounced reductions in hepatitis B e antigen (HBeAg) and HBsAg, associated with a transient alanine amino transferase (ALT) increase. Both HBsAg and HBeAg reductions and ALT increase were delayed in C57BL/6 SCID and chimeric mice, suggesting that adaptive immune responses may indirectly contribute. However, CD8+ T cell depletion in transduced wild-type mice did not impact antigen reduction, indicating that CD8+ T cell responses are not essential. Transient ALT elevation in AAV-HBV-transduced mice coincided with a transient increase in endoplasmic reticulum stress and apoptosis markers, followed by detection of a proliferation marker. Microarray data revealed antigen presentation pathway (major histocompatibility complex class I molecules) upregulation, overlapping with the apoptosis. Combination treatment with HBV-specific siRNA demonstrated that CAM-A-mediated HBsAg reduction is dependent on
de novo
core protein translation. To conclude, CAM-A treatment eradicates HBV-infected hepatocytes with high core protein levels through the induction of apoptosis, which can be a promising approach as part of a regimen to achieve functional cure.

IMPORTANCE

Treatment with hepatitis B virus (HBV) capsid assembly modulators that induce the formation of aberrant HBV core protein structures (CAM-A) leads to programmed cell death, apoptosis, of HBV-infected hepatocytes and subsequent reduction of HBV antigens, which differentiates CAM-A from other CAMs. The effect is dependent on the
de novo
synthesis and high levels of core protein.
African swine fever virus A137R assembles into a dodecahedron cage
Authors: Li Changyao , Jia Mingzhu , Hao Tianjiao , Peng Qi , Peng Ruchao , Chai Yan , Shi Yi , Song Hao , Gao George F.
Published: February 2024

African swine fever (ASF) is a highly contagious viral disease that affects domestic and wild pigs. The causative agent of ASF is African swine fever virus (ASFV), a large double-stranded DNA virus with a complex virion structure. Among the various proteins encoded by ASFV, A137R is a crucial structural protein associated with its virulence. However, the structure and molecular mechanisms underlying the functions of A137R remain largely unknown. In this study, we present the structure of A137R determined by cryogenic electron microscopy single-particle reconstruction, which reveals that A137R self-oligomerizes to form a dodecahedron-shaped cage composed of 60 polymers. The dodecahedron is literally equivalent to a
T =
1 icosahedron where the icosahedral vertexes are located in the center of each dodecahedral facet. Within each facet, five A137R protomers are arranged in a head-to-tail orientation with a long N-terminal helix forming the edge through which adjacent facets stitch together to form the dodecahedral cage. Combining structural analysis and biochemical evidence, we demonstrate that the N-terminal domain of A137R is crucial and sufficient for mediating the assembly of the dodecahedron. These findings imply the role of A137R cage as a core component in the icosahedral ASFV virion and suggest a promising molecular scaffold for nanotechnology applications.

IMPORTANCE

African swine fever (ASF) is a lethal viral disease of pigs caused by African swine fever virus (ASFV). No commercial vaccines and antiviral treatments are available for the prevention and control of the disease. A137R is a structural protein of ASFV that is associated with its virulence. The discovery of the dodecahedron-shaped cage structure of A137R in this study is of great importance in understanding ASFV pathogenicity. This finding sheds light on the molecular mechanisms underlying the functions of A137R. Furthermore, the dodecahedral cage formed by A137R shows promise as a molecular scaffold for nanoparticle vectors. Overall, this study provides valuable insights into the structure and function of A137R, contributing to our understanding of ASFV and potentially opening up new avenues for the development of vaccines or treatments for ASF.
Complete genome sequence of the
Microbacterium foliorum
bacteriophage Garey24
Authors: Migueletti Matías R. , García Rey Julieta , Micheloni Josefina , Lomanto Camila , Martelli Elisa , Sánchez Gastón , Colombo Julián M. , Vallecillo Luciano M. , Lamagni Francisco , Giusti Tomás , Acosta Fabrina , Villagrán Franco , Gvozdenovich Martín , Pricco Frakich Abril , Pianesi Tulio , Tulin Gonzalo , Mascali Florencia C. , Petitti Tomás D. , Torres Manno Mariano A. , Fusari Corina M. , Buttigliero Laura , Giordana María Florencia , Gramajo Hugo , Diacovich Lautaro , Espariz Martín , Mussi María Alejandra
Published: February 2024

In this work, we report the discovery and characterization of Garey24, a bacteriophage that forms medium-size plaques with halo rings isolated from a soil sample in Funes, Argentina. Its 41,522 bp circularly permuted genome contains 63 putative protein-coding genes. Based on gene content similarity, Garey24 was assigned to subcluster EA1.
In vitro
lung epithelial cell model reveals novel roles for
Pseudomonas aeruginosa
siderophores
Authors: Kang Donghoon , Xu Qi , Kirienko Natalia V.
Published: February 2024

The multidrug-resistant pathogen
Pseudomonas aeruginosa
is a common nosocomial respiratory pathogen that continues to threaten the lives of patients with mechanical ventilation in intensive care units and those with underlying comorbidities such as cystic fibrosis or chronic obstructive pulmonary disease. For over 20 years, studies have repeatedly demonstrated that the major siderophore pyoverdine is an important virulence factor for
P. aeruginosa
in invertebrate and mammalian hosts
in vivo
. Despite its physiological significance, an
in vitro
, mammalian cell culture model that can be used to characterize the impact and molecular mechanisms of pyoverdine-mediated virulence has only been developed very recently. In this study, we adapt a previously-established, murine macrophage-based model to use human bronchial epithelial (16HBE) cells. We demonstrate that conditioned medium from
P. aeruginosa
induced rapid 16HBE cell death through the pyoverdine-dependent secretion of cytotoxic rhamnolipids. Genetic or chemical disruption of pyoverdine biosynthesis decreased rhamnolipid production and mitigated cell death. Consistent with these observations, chemical depletion of lipids or genetic disruption of rhamnolipid biosynthesis abrogated the toxicity of the conditioned medium. Furthermore, we also examine the effects of exposure to purified pyoverdine on 16HBE cells. While pyoverdine accumulated within cells, it was largely sequestered within early endosomes, resulting in minimal cytotoxicity. More membrane-permeable iron chelators, such as the siderophore pyochelin, decreased epithelial cell viability and upregulated several pro-inflammatory genes. However, pyoverdine potentiated these iron chelators in activating pro-inflammatory pathways. Altogether, these findings suggest that the siderophores pyoverdine and pyochelin play distinct roles in virulence during acute
P. aeruginosa
lung infection.

IMPORTANCE

Multidrug-resistant
Pseudomonas aeruginosa
is a versatile bacterium that frequently causes lung infections. This pathogen is life-threatening to mechanically-ventilated patients in intensive care units and is a debilitating burden for individuals with cystic fibrosis. However, the role of
P. aeruginosa
virulence factors and their regulation during infection are not fully understood. Previous murine lung infection studies have demonstrated that the production of siderophores (e.g., pyoverdine and pyochelin) is necessary for full
P. aeruginosa
virulence. In this report, we provide further mechanistic insight into this phenomenon. We characterize distinct and novel ways these siderophores contribute to virulence using an
in vitro
human lung epithelial cell culture model.
Supplemental Material: Crustal evolution of a continental magmatic arc from subduction to collision: A case study in the Gangdese arc, southern Tibetan Plateau
Authors: Zhang Zeming , et al.
Published: February 2024

Text S1: Analytical Methods. Figure S1: Zircon cathodoluminescence images of the granites from the eastern Gangdese arc, with U-Pb dating locations and ages (in Ma). Table S1: Zircon U-Pb dating and trace element data of the late Mesozoic and Cenozoic granites of the eastern Gangdese arc. Table S2: Whole-rock chemical compositions of the late Mesozoic and Cenozoic granites of the eastern Gangdese arc. Table S3: Whole-rock Sr and Nd isotopic compositions of the late Mesozoic and Cenozoic magmatic rocks of the eastern Gangdese arc. Table S4: Zircon Hf isotopic data of the late Mesozoic and Cenozoic granites of the eastern Gangdese arc.
All-cause mortality risks among participants in mass-participation sporting events
Authors: Bakker Esmée A , Aengevaeren Vincent L. , Lee Duck-Chul , Thompson Paul D , Eijsvogels Thijs M.H.
Published: February 2024

Objectives

Exercise transiently increases the risk for sudden death, whereas long-term exercise promotes longevity. This study assessed acute and intermediate-term mortality risks of participants in mass-participation sporting events.

Methods

Data of participants in Dutch running, cycling and walking events were collected between 1995 and 2017. Survival status was obtained from the Dutch Population Register. A time-stratified, case-crossover design examined if deceased participants more frequently participated in mass-participation sporting events 0–7 days before death compared with the reference period (14–21 days before death). Mortality risks during follow-up were compared between participants and non-participants from the general population using Cox regression.

Results

546 876 participants (median (IQR) age 41 (31–50) years, 56% male, 72% runners) and 211 592 non-participants (41 (31–50) years, 67% male) were included. In total, 4625 participants died of which more participants had partaken in a sporting event 0–7 days before death (n=23) compared with the reference period (n=12), and the mortality risk associated with acute exercise was greater but did not reach statistical significance (OR 1.92; 95% CI 0.95 to 3.85). During 3.3 (1.1–7.4) years of follow-up, participants had a 30% lower risk of death (HR 0.70; 95% CI 0.67 to 0.74) compared with non-participants after adjustment for age and sex. Runners (HR 0.65; 95% CI 0.62 to 0.69) and cyclists (HR 0.70; 95% CI 0.64 to 0.77) had the best survival during follow-up followed by walkers (HR 0.88; 95% CI 0.80 to 0.94).

Conclusion

Participating in mass-participation sporting events was associated with a non-significant increased odds (1.92) of mortality and a low absolute event rate (4.2/100 000 participants) within 7 days post-event, whereas a 30% lower risk of death was observed compared with non-participants during 3.3 years of follow-up. These results suggest that the health benefits of mass sporting event participation outweigh potential risks.