bluuebunny/crossref_metadata_2025 huggingface dataset:
Data-Driven Modeling for Design and Control of Adaptive Wind Turbine Blades
Authors: Roetzer James , Hall John , Li Xingjie , Boik Hunter , Janke Ben
Published: January 2025

In the field of wind energy, there is an ongoing need for improvements in efficiency and control. To achieve this, morphing aerostructures can be utilized alongside data-driven methods, combining performance improvements with new methods of system control. Presented here, data driven models are developed for the IEA 15 MW reference turbine, which relate the aerodynamic thrust load, a performance parameter chosen for its significance in fatigue studies, to the control inputs of a twist-morphing adaptive rotor blade. OpenFAST simulations are used to collect data, which then trains a variety of regression-based data-driven models: decision trees, state vector machines (SVM), neural networks (NN), and gaussian process regression (GPR). In addition to the models produced for the whole set of simulated data, the data was also partitioned into high- and low-wind speed data sets, and the modelling process was repeated for each as a new case. Through comparing the performance for each model and each case, GPR was shown to be the most accurate, with a root-mean-square error (RMSE) lower than all other models for all cases examined. GPR also was comparably fast to its competing models in all cases, however, prediction speed was more volatile than accuracy, with each case having a different optimal model in terms of prediction speed. Notable observations include that while GPR approximately maintained its accuracy across all cases, accuracy for NN and SVM changed significantly. Between the full data set and high wind speed data subset, SVM performed 39.7% better on training data and 23.3% better on test data with regards to RMSE in the high-wind speed data set. Meanwhile, NN performed 17.5% better on test data, but 19.8% worse on training data with regard to RMSE, both observations implying that GPR may have less dependency on the data sampling range, for this application specifically.
Characterization of Wake Flow Dynamics and Energy Transport in Vortex-Induced Vibration Systems: A Low Reynolds Number Investigation
Authors: Albano Jooi , Avros Ilya , Fershalov Andrei , Orlandini Pieter , Elvin Niell , Liu Yang
Published: January 2025

Vortex Induced Vibration (VIV) is a phenomenon where a structure in a flowing fluid oscillates due to vortex formation and shedding. While it can cause structural fatigue, it also offers potential for sustainable energy generation. This study examines the flow behavior around an elastically mounted cylindrical bluff body in low Reynolds number (Re < 4000) flows to enhance the understanding and efficiency of VIV systems for novel fluidic energy harvesters. Since energy production in these systems is dominated by the amplitude of vibration, fully understanding and quantifying the fluid-structure interaction in these systems is critical. We analyze the wake flow characteristics of elastically mounted cylinders in both vibrating and non-vibrating modes, as well as the energy transport during dynamic processes. The study uses a 40 mm diameter cylinder supported by aluminum beams, with Particle Image Velocimetry (PIV) to measure wake flow characteristics. The VIV regimes are categorized into pre-vibration, vibration, and post-vibration regimes. The results show the differences in flow patterns and energy system behaviors between vibrating and non-vibrating cylinders, which include wake pattern symmetry, saddle point and flow separation point locations, lack of recirculation regions, and higher RSS and TKE values in the vibrating case. The asymmetry in wake patterns arises from vibrational motion, with higher turbulence indicated by increased RSS and TKE. Although vorticity is higher post-vibration, the motion remains stable, indicating that the vibrational motion resulting from vortex shedding is due to a combination of both structural and fluidic instabilities. Energy transport dynamics show a higher energy drop percentage for the vibrating case. This research advances the understanding of VIV mechanisms and lays the groundwork for optimizing VIV energy harvesters, particularly in arrays of multiple cylinders. The findings contribute to the development of more efficient renewable energy technologies.
An Experimental-Based Analytical Study on the Sublimation Process of Frozen Colloidal Droplet
Authors: Zhang Xiaoxiao , Zhang Haipeng , Liu Yang
Published: January 2025

This paper investigates the fundamentals of sublimation processes and the associated deposit morphology formations in a freezing-based inkjet 3D printing technique. The freezing-sublimation method involves freezing a colloidal droplet and subsequently removing the solvent through sublimation, leaving behind colloidal particles that form the final printed morphology. A theoretical framework is developed to describe the transition from a solid ice droplet with embedded colloidal particles to a dry pattern deposited on a substrate. The study explores two thermodynamic processes for achieving sublimation: Process (A), conducted in a vacuum at a constant sub-freezing temperature, and Process (B), achieved through heating at constant low pressure. Experimental data provide insights into the mass and heat transfer dynamics during sublimation, revealing variations in sublimation rates and their influence on the resulting deposition morphologies. While the theoretical model is in its initial stages, the current study focuses on experimental observations, with future work linking these observations to the theoretical framework.
Post-Processing of Additively Manufactured SS316 Employing Die Sinking EDM
Authors: Ali Shahid , Talamona Didier , Perveen Asma
Published: January 2025

Selective laser melting (SLM) stands out as an additive manufacturing (AM) technique enabling the production of highly complex, fully functional metallic parts with some limitations of poor surface roughness and average mechanical properties. The SLM-produced specimens demonstrated an average surface roughness of 11.25 μm, and an average microhardness of approximately 201HV. There are numerous surface treatments reported in the literature both conventional (milling) and non-conventional (laser polishing, chemical polishing, abrasive finishing, and Surface Mechanical Attrition Treatment (SMAT)). However, these secondary surface treatments face challenges such as significantly extended processing time, effectiveness for finishing complex parts, and applicability is limited to certain materials. In this study, an unconventional technique Die-sinking electro-discharge machining (EDM) has been proposed to improve the surface quality of AM specimens. Stainless Steel SS316, a ferritic chromium-nickel stainless steel containing purposeful amounts of molybdenum, exhibits enhanced general corrosion resistance. SS316 is the preferred choice for pharmaceutical equipment, cryogenic piping, pulp and paper, and food industries. This study delves into investigating the effect of machining conditions (Ip, Ton, and Toff) on the surface integrity of SLM-printed SS316 employing die-sinking EDM. The results of experiments manifest that at higher levels of pulse current and pulse on time, the surface roughness and surface microhardness of the printed specimens are improved to 3.72μm and 341.667 HV, respectively.
An Intuitive Mechanism for Position Control of the Medical Robotic Systems
Authors: Magee Kyra , Yu Mingxuan , Rayapudi Praneeth , Riad Jacob , Sellers Stephan , Abbadi Sama , Ashuri Turaj , Amiri Moghadam Amir Ali
Published: January 2025

The control and manipulation of medical robotic systems present significant challenges. They often require a steep learning curve due to the need for more intuitive control mechanisms, particularly in existing joystick designs. This paper introduces a novel approach to address these challenges by developing a master/slave system utilizing a twin Stewart mechanism configured as a specialized joystick with six degrees of freedom (DOF). This design enhances the intuitiveness of robot motion, enabling surgeons to control the robot’s end-effector with one hand. The design objectives for the joystick emphasize six DOF, complete one-handed control, and intuitive usability within a compact workspace. A Stewart mechanism is chosen for its inherent six DOF and suitability as the master system for a soft robot. Advanced 3D printing techniques will manufacture the mechanism, with linear potentiometers mounted on each leg to sense displacement. These displacements are translated into equivalent motions in the soft robot through non-linear mapping techniques and refined through manual calibration. The robot’s position will be monitored using an electromagnetic tracker and mapped to its bending deformation, providing feedback to the controller. This paper presents an approach to controlling a soft robotic system and enhancing usability in surgical applications.
Research Experiences via Independent Studies at a Primary Undergraduate Institute
Authors: Manoharan Sanjivan , Kocharian Tikran
Published: January 2025

While Project Based Learning (PBL) is a valuable tool for enhancing the learning abilities of undergraduate students, it often becomes more instructional akin to a laboratory activity, potentially restricting autonomous learning. Conversely, independent studies, if conducted effectively, present significant opportunities for undergraduate research and the strengthening of critical thinking skills. They are also an ideal vehicle for engaging in the complete design thinking process. Moreover, these studies can be strategically leveraged to strengthen the research productivity of faculty, especially at a Primary Undergraduate Institute (PUI). This paper provides an overview of 13 such independent studies conducted over six years and how they were systematically used to develop the research track of the authors despite the heavy teaching focus at the PUI. All independent study topics pertained to either fluid mechanics or heat transfer enhancement. The benefits to the students, authors, and the engineering department are also discussed. The faculty observations regarding the students’ progress before and after the study are also presented. Throughout each independent study, the students were exposed to the comprehensive design thinking cycle, i.e., empathize, define, ideate, prototyping, and results.
A Microlaser-Based Magnetic Field Sensor
Authors: Sakib Md Nazmus , Manzo Maurizio
Published: January 2025

Dye-doped polymer-based microlasers are recognized for their sensitivity and low-threshold lasing, making them highly effective sensors. However, their non-magnetic nature limits their deployment in hard-to-reach areas. Magnetic microspheres offer a solution to this limitation because of their easy maneuverability. The study investigates the elastic deformation of microlasers and the resulting shift in optical modes induced by magnetic field. In this study, a magnetic field sensor using a microlaser is developed. The microlaser is composed of NBA 107 UV curable polymer, rhodamine 6G dissolved in an ethanol solution, and Fe2NiO4 nanopowder with a size of < 50 nm. A Helmholtz coil is employed to generate a magnetic field, which induces deformation in the microlaser. This deformation alters the optical path of the light, leading to a shift in the position of the laser modes. This shift can be utilized to detect the strength of the surrounding magnetic field. The microlaser is excited using a Q-switched Nd:YAG laser. The light emitted from the microlaser is then collected using an optical spectrometer that is connected to a cooled CCD camera. Preliminary calibration experimental curves correlating the external magnetic field with the shift of the laser modes are shown herein.
A Teaching Model to Engage Students in Massive Online Courses
Authors: Sayeg-Sánchez Gibrán , Rocha Gerardo , Rodríguez-Paz Miguel X.
Published: January 2025

This evidence-based study presents evidence of the implementation of a teaching model that promotes interaction among students and teachers in Massive Online Courses (MOCs). The results showed a positive impact on engagement and motivation for learning in an Engineering Continuing Education group of students. The proposed teaching model was implemented in 2023 during a Project Management micro course, with 150 graduated engineers. The model was based on our University’s Continuing Education framework, which allows the design of meaningful content based on adult learning principles: learning must be self-directed, learning is biased by previous experiences, and learning must be straightforward and applicable in the real world; and it was leveraged with the use of digital tools during impartation. After implementation, evidence of a positive influence on students’ motivation and engagement was collected. An active participation ratio of 54% of the attendees was recorded, higher than the average participation rate of 40% recorded in other studies. Similarly, according to Kirkpatrick’s evaluation model, it was found evidence of positive influence on the Reaction and Behavior levels.
Advancing Autonomous Backing of Tractor-Trailer Systems: a Dynamic Model Approach
Authors: Sah Dhirendra K. , Selekwa Majura F.
Published: January 2025

Recent developments in sensing and information processing technology have seen an increased interest in applications of autonomous vehicles. Many driverless vehicles have been tested in various places and environments across the world. Automated backing of tractor-trailer systems is one of the problems yet to be fully addressed in this endeavor, even experienced drivers find it challenging to perform backup maneuvers of tractor-trailer systems in confined spaces. Achieving a fully automated backup maneuver of a tractor-trailer vehicle requires, among other things, the presence of a high-fidelity mathematical model of the vehicle. Often this problem is approached from a kinematic standpoint where the vehicle and the trailer are modeled using a bicycle structure formulation by concentrating weights at the axle centers only, which limits not only the maneuverability of the vehicle system but also its speed. This paper proposes a dynamic model of a tractor-trailer that treats the system as a finite structure of interconnected multi-bodies subjected to various forces and moments emanating from terramechanics and other non-conservative forces acting on the vehicle. This approach presents are more realistic motion of the vehicle even in confined spaces enabling it to avoid colliding with unintended objects during the maneuver. Simulation results by using such a model show that the vehicle can autonomously perform back up maneuvers in as limited clearances as 5% of the vehicle width at moderate speeds without significant slip.
Design and Development of a Desktop 3D Printer for Conformal Additive Manufacturing
Authors: Ahmed Radif Uddin , Dowell Ethan , Alam Chowdhury Sadid , Rahman M. Shafiqur
Published: January 2025

This study presents a conformal 3D printing strategy by developing a direct ink writing (DIW) 3D printer that can execute an algorithm for a conformal print path in the form of a G-code. DIW printers fall under the class of extrusion-based 3D printers that can deposit non-Newtonian material through the nozzle, utilizing solely the rheological properties of the feedstock material, known as the “ink.” The custom-made DIW 3D printer’s performance is tested with the deposition of petroleum jelly on a curved surface, which serves as the conformal substrate. The conformal print algorithm starts by scanning the conformal substrate using a laser profiler to obtain detailed geometric information about the surface. This information is then combined with the 3D model, printed on the substrate, and imported into the algorithm. The algorithm analyzes the geometry of the surface and projects the perimeter of the 3D model onto the conformal substrate, ensuring alignment. Once the periphery printing information is obtained, the algorithm generates the print path for the infills, i.e., internal structures of the object. This process is repeated layer by layer until the final layer of the printing process is reached. The accuracy of the proposed algorithm is validated by printing a 3D object and comparing it to the original model. Results show that the algorithm provides an accurate print path for extruding material on a non-planar substrate. The algorithm can also generate a hybrid print path for added flexibility. The successful implementation of this algorithm is demonstrated through the layer-wise printing of a 3D object. Overall, this study provides a valuable solution for printing customizable parts via a conformal additive manufacturing process.
Investigating Passive Drag Reduction Through Nature Inspired Surface Textures
Authors: Niemiec Kenneth , Thornton Nicholas , Gnanaskandan Aswin , Ebadi Alireza
Published: January 2025

This project sought to reduce resistive drag forces on complex bodies through the implementation of biologically inspired surface textures. We accomplished this by investigating the effects of riblets on drag forces for flow over an airfoil. Our team conducted wind tunnel experiments and ANSYS Fluent simulations in 2D and 3D to evaluate the effectiveness of these riblets in reducing drag on an airfoil. From this research, we found that our designs could reduce drag forces by about 5% over a Reynolds number interval of 70,000 to 115,000 and up to 13% at the low Reynolds number of 45,000. This led us to recommend their implementation on small or low-speed components, as our findings can increase the efficiency of vehicles operating at moderate Reynolds numbers.
Investigating Fracture Behavior in Porous Media Using Phase-Field and Asymptotic Homogenization
Authors: Nielsen Ryan H. , Newell Pania
Published: January 2025

Porous media make up many of the most important materials around us. When these materials fail structurally, the results are often catastrophic. Therefore, the prediction of fracture in these materials has been a crucial focus for researchers and engineers for decades. We argue that geometric variation in microscale pore morphology affects course-scale crack propagation. We develop a framework that first calculates an effective continuum-level constitutive tensor based on asymptotic homogenization theory. This homogenized constitutive tensor serves as an input to a linear elastic brittle fracture mechanics model. This work implements the phase-field variational formulation based on Griffith’s classical energy balance to analyzes pore shapes of varying topological complexity. Here, we analyze cases with circular, rectangular, and 2 irregular pore shapes. The macroscale crack propagation and path for a 2D classical tensile loading problem can then be compared when using effective constitutive tensors corresponding to different pore-shape indices. Preliminary results show that crack advancement is appreciably altered even when porosity is held constant for pore morphologies with differing shape shapes, highlighting the need for further investigation into the relationship between pore structure and fracture behavior.
Microstructure Evolution and Forming Mechanism of Hollow Drive Shafts by Multi-Roll Tandem Skew Rolling
Authors: Zhang Song , Shu Xuedao , Chen Yusen , Cen Zewei , Li Zixuan , Xu Haijie , Wang Jitai
Published: January 2025

Traditional rolling forming processes are often limited by a maximum cross-sectional reduction rate of 75%, which cannot meet the demands for heavy cross-sectional reduction rate components such as hollow drive shafts. This paper proposes an innovative multi-roll tandem skew rolling (MRTSR) process for forming hollow drive shafts. The paper first elaborates on the basic principles of the MRTSR process and highlights its advantages in reducing rolling force and enhancing stability compared to traditional single-roll systems. Subsequently, through kinematic analysis, stable rolling conditions for hollow drive shafts by MRTSR are established. Next, a finite element model is established, and the stress-strain field, temperature field, and microstructure field distributions during the rolling process are analyzed. The results show that when the pitch of the front roller system acting on the rolling piece is greater than or equal to that of the rear roller system, stable rolling of the hollow drive shaft by MRTSR can be achieved. Additionally, the strain, temperature, and microstructure field of the rolled piece are uniformly distributed along the axial direction, while they gradually decrease in a gradient manner along the radial direction. The proposed MRTSR process provides a new feasible method for producing high-quality hollow drive shafts with large cross-sectional reductions.
Digital Twin Model for Property Assessment of Metal Additive Manufacturing
Authors: Marks Malik , Chowdary Chigurupati Poojith , Taheri Hossein
Published: January 2025

Additive manufacturing (AM) has revolutionized the manufacturing industry by offering flexibility, customization, and rapid prototyping capabilities. Complex geometries and low volume parts can be produced via AM in much lower lead time and cost compared to traditional manufacturing methods. However, ensuring the quality and reliability of AM parts remains a significant challenge due to variations in material properties and process parameters. Traditional material property analysis methods, that require experimental testing and computational modeling, are often costly and time-consuming and often not applicable to the complex geometries of AM components. These challenges are further magnified when repetitive sampling is required. To address these challenges, this paper presents a novel approach that combines experimental findings with Finite Element Modeling (FEM) to construct a digital twin (DT) model of AM parts. The DT model will serve as a virtual representation along with real-time monitoring, simulation, and optimization capabilities. Numerical simulations are conducted to correlate the resonance frequency of parts at different process conditions with their material characteristics, represented as RF Z-score values. Hence, the results suggest that such an approach provides manufacturers with cost-effective and efficient means of analyzing material properties and optimizing AM processes. Moreover, by leveraging digital twin technology, manufacturers can achieve greater process control and quality assurance in additive manufacturing. The findings of this study contribute to advancing the understanding and implementation of digital twin technology in AM; therefore, paving the way for enhanced productivity and reliability in additive manufacturing processes.
Investigation on the Impact of Preform Temperature Distribution and Reduction Ratio on Final Part in Ironing Process
Authors: Yarşılıkal Solmaz Buse , Özaslan Emre , Tursun Hüseyin
Published: January 2025

Hot metal forming represents a critical and indispensable phase within the production processes of a wide spectrum of manufactured goods. Among the most ancient techniques in metal forming, drawing facilitates the achievement of superior surface textures and precise measurements in lengthy objects with uniform cross-sectional profiles. In deep drawing, ironing is achieved by regulating the gap between the punch and the rings, enabling the material to flow over the punch. [1] When employing a mobile punch in the ironing process, the punch moves in sync with the speed at which the section emerges from the die. This technique finds extensive application in reducing the thickness of walls in drawn cups or shells, as seen in the production of items like beverage cans or artillery shells, for instance. [2]

While deep drawing is widely used for high-strength, low-formability metals in industrial applications, conducting it at ambient temperatures poses challenges due to significant deformation and elevated flow stresses. [3] This often results in creases and imperfections on the product surface. Elevated temperatures enhance formability, making deformations more manageable. The selection of the deformation temperature is crucial, especially for steel parts, where a relatively high temperature is required, potentially explaining the limited research on this material. [3, 4] Based on a finite element method (FEM) simulation, ironing deep-drawn cups reduced residual stresses by 50% to 65%.[5] This process enhances geometric accuracy and reduces residual stresses effectively.[6] Additionally, increasing the level of ironing generates compressive axial stresses on the outer surface, counteracting tensile residual stresses. [7]
Solution of Differential-Algebraic Equations Through Symbolic Index Reduction
Authors: Stocco Davide , Larcher Matteo , Biral Francesco , Bertolazzi Enrico
Published: January 2025

Differential-Algebraic Equations (DAEs) are crucial for modeling and simulating dynamical systems such as mechanisms, electrical circuits, and chemical reactions. However, the numerical solution of DAEs can be challenging due to their high index, which indicates the minimum number of differentiations needed to transform the DAE system into an equivalent system of Ordinary Differential Equations (ODEs) with invariants. Index reduction is a preliminary step in the numerical integration of high-index DAEs that reduces the system’s complicatedness and enables the use of standard ODE solvers. This research introduces an index reduction algorithm based on symbolic computation, which utilizes matrix factorization and differentiation to reduce DAEs’ index. Special attention is given to the mitigation of expression swell. A hierarchical representation technique is employed not only to address this issue but also to improve the reduction processes with the introduction of index-1 variables. The algorithm is implemented in the Indigo library, which combines Maple®’s symbolic manipulation capabilities with Matlab®’s numerical computation capabilities. Validation across various benchmarks demonstrates the algorithm’s effectiveness in reducing high-index systems and showcases its implementation robustness in numerical integration. Overall, the proposed methodology provides a reliable means for addressing generic DAE systems linear in the states’ derivatives.
Assessing the Resilience of 77 GHz Radar Sensors in Autonomous Vehicles: A Multiphysics Simulation Approach for Low-Speed Collisions Leading to Significant Radome Deformations
Authors: Kumar Meenakshisundaram Satish , Chipengo Ushe , Shejwal Amogh
Published: January 2025

Autonomous vehicles (AVs) promise to revolutionize transportation with enhanced safety and accessibility, relying on sensors like 77 GHz Radar for object detection. However, crash-induced deformations in bumpers and radomes that house these sensors can compromise their functionality. Traditional physical testing is costly and impractical, prompting the use of Multiphysics simulations. This study employs finite element solvers to predict sensor performance post-collision. Focusing on low-speed collisions, the study assesses the impact on detection range and field of view, crucial for continued safe operation until repairs. By simulating various collision scenarios, the study proposes a simulation workflow as a potent tool to swiftly address challenges in product development, thereby enhancing the reliability of AVs and fostering safer transportation.
Macro and Micro-Scale Computational Modeling of Laser Powder Bed Fusion of Co-Cr Alloy
Authors: Kumar Mohit , Sharma Varun
Published: January 2025

Laser powder bed fusion (LPBF) revolutionizes additive manufacturing (AM) with precise fabrication for aerospace and biomedical uses, including dental applications of cost-effective cobalt-chromium (Co-Cr) alloys known for their excellent properties. Challenges like porosity control, surface quality, and residual stresses hinder LPBF-based AM from advancing beyond prototypes, but optimized process understanding and modeling can improve part quality. This study focuses on the computational modeling of the LPBF technique applied to Co-Cr alloy using simulation software. Simulation software was used to investigate both macroscale and microscale aspects of AM processes. Macroscale level, including powder flow characteristics, laser-powder interactions, and macroscopic thermal gradients during fabrication. Also, microscale analysis was done on intricate aspects such as melt pool dynamics, solidification behavior, and microstructural evolution within the manufactured part. Various process parameters, such as laser power and scan speed, were investigated for their influence on the final part quality. Through systematic parametric studies, the model identifies optimal process parameters that minimize defects such as porosity and lack of fusion while maximizing mechanical properties and dimensional accuracy. This was done by combining macroscale and microscale studies to produce high-quality components without wasting materials, energy, and other resources. The results found that as laser power increased from 100 W to 200 W, the molten pool’s width and depth also increased. Conversely, the molten pool’s size decreased as the scanning speed rose from 1250 mm/s to 1750 mm/s. A laser power of 150 W and scanning speed of 1500 mm/s could produce higher-quality components, with coarser grain structures observed under optimized conditions.
Examination of Turbulent Kinetic Energy Transfer in Realistic Premixed Reacting Flows
Authors: Souders Kelsea O. , Hamlington Peter E.
Published: January 2025

We investigate the kinetic energy flux across different spatial scales for a premixed flame in a realistic configuration. We use PeleC, a fully-compressible reacting flow code with adaptive mesh refinement, to obtain a fully-resolved flow field for a bluff body stabilized premixed methane-air flame situated within a converging nozzle and subjected to free-stream turbulence. We apply Gaussian filters of multiple sizes to the simulation data to evaluate the net kinetic energy flux between resolved (i.e., large) and sub-grid (i.e., small) scales, with transfer from small to large scales corresponding to energy “backscatter”. Using three filter sizes, we find that there is statistically-significant amounts of backscatter towards the unburned side of the flame, coinciding with regions of high flame-generated enstrophy production due to baroclinic torque. Despite the same general trends recovered through each of the filters, backscatter is more pronounced for the smaller filter widths that are a fraction of the thermal flame thickness, indicating that backscatter becomes less pronounced further from the flame scale in this flow.
Downburst-Induced Maximum Dynamic Response of a Monitored Structure: Reliability of the Thunderstorm Gust Response Factor
Authors: Roncallo Luca , Mengistu Mekdes Tadesse , Tubino Federica , Repetto Maria Pia
Published: January 2025

In this study, the Thunderstorm Gust Response Factor (TGRF) technique is applied for the estimate of the maximum dynamic response of a full-scale monitored slender vertical structure subjected to the impact of a thunderstorm downbursts. The considered structure is a lighting pole equipped with an ultrasonic anemometer as well as strain gauges and accelerometers. The top displacement estimated starting from the recorded accelerations and deformations is compared with the maximum response based on the TGRF approach. The parameters of the slowly-varying mean wind speed are extracted from the time history recorded by the anemometer and a nose-shaped mean wind profile is assumed. Due to the uncertainties on the dynamic and aerodynamic parameters of the structure, as well as the wind turbulence, a range of variation for each of these parameters is defined and the interval of variation of the maximum response is estimated. The comparison between the recorded maximum response and the interval of variation estimated through the TGRF confirms the reliability of the proposed technique.
Enhancing Prosthetic and Orthopedic Support Devices Through Advanced Composite Material Assembly and Design Optimization
Authors: Akrache Radouane , Mohammed Ridha Shakir Wafaa , Charafeddine Jinan
Published: January 2025

The landscape of medical technology, particularly in prosthetics and orthopedic supports, is on the cusp of a transformation driven by integrating advanced composite materials such as carbon fiber. This paper presents a novel approach to the assembly of these materials, focusing on the development and optimization of smooth inserts tailored to medical applications. To overcome the limitations of conventional assembly methods, this study investigates the geometric optimization of inserts to improve the mechanical performance and durability of composite medical devices. Through a combination of theoretical modeling, simulation, and empirical testing, we demonstrate the potential of our approach to significantly improve device reliability, leak-tightness, and patient comfort. The work highlights the importance of advanced assembly techniques to fully exploit the capabilities of composite materials. It offers a route to medical devices that are not only functionally superior but also better suited to the needs of the user. Our results promise a new generation of prostheses and orthopedic supports that better integrate with human physiology and represent a significant step forward in patient-centered care.
Through-the-sensor sub-bottom imaging using the self-noise of an autonomous underwater vehicle
Authors: Sabra Karim G. , Pfenninger Paige , Lin Ying-Tsong
Published: January 2025

This work demonstrates the feasibility of performing through-the-sensor (TTS) sub-bottom imaging using low-frequency ([100 Hz-1kHz]) self-noise generated by the propulsion of an autonomous underwater vehicle (AUV) acting as a source of opportunity. The self-noise was recorded by a short towed horizontal line array (11.4 m aperture) by the same AUV while it operated ∼35 m above the seabed along a range-dependent section at the New England shelf break. The seabed and sub-bottom layers imaged by this TTS method were found to be consistent with the images simultaneously obtained at higher frequency [2.5–4.5 kHz] using a conventional active source mounted on the AUV.
Variable impacts of land-based climate mitigation on habitat area for vertebrate diversity
Authors: Smith Jeffrey R. , Beaury Evelyn M. , Cook-Patton Susan C. , Levine Jonathan M.
Published: January 2025

Pathways to achieving net zero carbon emissions commonly involve deploying reforestation, afforestation, and bioenergy crops across millions of hectares of land. It is often assumed that by helping to mitigate climate change, these strategies indirectly benefit biodiversity. Here, we modeled the climate and habitat requirements of 14,234 vertebrate species and show that the impact of these strategies on species’ habitat area tends not to arise through climate mitigation, but rather through habitat conversion. Across locations, reforestation tends to provide species more habitat through both land-cover change and climate mitigation, whereas habitat loss from afforestation and bioenergy cropping typically outweighs the climate mitigation benefits. This work shows how and where land-based mitigation strategies can be deployed without inadvertently reducing the area of habitat for global biodiversity.
Mechanically robust and stretchable organic solar cells plasticized by small-molecule acceptors
Authors: Wang Zhenye , Zhang Di , Yang Lvpeng , Allam Omar , Gao Yerun , Su Yang , Xu Meichen , Mo Songmin , Wu Qinghe , Wang Zhi , Liu Junfeng , He Jiayi , Li Rui , Jia Xingwang , Li Zhilin , Yang Long , Weber Mark D. , Yu Yu , Zhang Xinliang , Marks Tobin J. , Stingelin Natalie , Kacher Josh , Jang Seung Soon , Facchetti Antonio , Shao Ming
Published: January 2025

Emerging wearable devices would benefit from integrating ductile photovoltaic light-harvesting power sources. In this work, we report a small-molecule acceptor (SMA), also known as a non–fullerene acceptor (NFA), designed for stretchable organic solar cell (
s
-OSC) blends with large mechanical compliance and performance. Blends of the organosilane-functionalized SMA BTP-Si4 with the polymer donor PNTB6-Cl achieved a power conversion efficiency (PCE) of >16% and ultimate strain (ε
u
) of >95%. Typical SMAs suppress OSC blend ductility, but the addition of BTP-Si4 enhances it. Although BTP-Si4 is less crystalline than other SMAs, it retains considerable electron mobility and is highly miscible with PNTB6-Cl and is essential for enhancing ε
u
. Thus,
s
-OSCs with PCE > 14% and operating normally under various deformations (>80% PCE retention under an 80% strain) were demonstrated. Analysis of several SMA-polymer blends revealed general molecular structure–miscibility–stretchability relationships for designing ductile blends.
Photo-induced chirality in a nonchiral crystal
Authors: Zeng Z. , Först M. , Fechner M. , Buzzi M. , Amuah E. B. , Putzke C. , Moll P. J. W. , Prabhakaran D. , Radaelli P. G. , Cavalleri A.
Published: January 2025

Chirality, a pervasive form of symmetry, is intimately connected to the physical properties of solids, as well as the chemical and biological activity of molecular systems. However, inducing chirality in a nonchiral material is challenging because this requires that all mirrors and all roto-inversions be simultaneously broken. Here, we show that chirality of either handedness can be induced in the nonchiral piezoelectric material boron phosphate (BPO
4
) by irradiation with terahertz pulses. Resonant excitation of either one of two orthogonal, degenerate vibrational modes determines the sign of the induced chiral order parameter. The optical activity of the photo-induced phases is comparable to the static value of prototypical chiral α-quartz. Our findings offer new prospects for the control of out-of-equilibrium quantum phenomena in complex materials.
Behaviorally designed training leads to more diverse hiring
Authors: Arslan Cansın , Chang Edward H. , Chilazi Siri , Bohnet Iris , Hauser Oliver P.
Published: January 2025

A field experiment provides a promising proof of concept
Systematic identification of Y-chromosome gene functions in mouse spermatogenesis
Authors: Subrini Jeremie , Varsally Wazeer , Balsells Irina Balaguer , Bensberg Maike , Sioutas Georgios , Ojarikre Obah , Maciulyte Valdone , Gylemo Björn , Crawley Katharine , Courtis Katherine , de Rooij Dirk G. , Turner James M. A.
Published: January 2025

The mammalian Y chromosome is essential for male fertility, but which Y genes regulate spermatogenesis is unresolved. We addressed this by generating 13 Y-deletant mouse models. In
Eif2s3y
,
Uty
, and
Zfy2
deletants, spermatogenesis was impaired. We found that
Uty
regulates spermatogonial proliferation, revealed a role for
Zfy2
in promoting meiotic sex chromosome pairing, and uncovered unexpected effects of Y genes on the somatic testis transcriptome. In the remaining single Y-gene deletants, spermatogenesis appeared unperturbed, but testis transcription was still altered. Multigene deletions, including a human-infertility AZFa model, exhibited phenotypes absent in single Y deletants. Thus, Y genes may regulate spermatogenesis even if they show no phenotypes when deleted individually. This study advances our knowledge of Y evolution and infertility and provides a resource to dissect Y-gene functions in other tissues.
Expanding the brain’s terrain for reward
Authors: Grillner Sten
Published: January 2025

A previously unknown region in the brainstem controls dopamine activity
In Other Journals
Authors: Vignieri Sacha , Ross Sarah H. , Osborne Ian S. , Jiang Di , Jin Sumin , Ash Caroline , Stajic Jelena
Published: January 2025

Editors’ selections from the current scientific literature
A rhamnose-rich O-antigen of
Paraburkholderia phymatum
MP20 is required for symbiosis with
Mimosa pudica
Authors: Welmillage Shashini U. , James Euan K. , Tak Nisha , Shedge Sonali , Huang Lei , Muszyński Artur , Azadi Parastoo , Gyaneshwar Prasad
Published: January 2025

Paraburkholderia phymatum,
a β-proteobacterium, forms a nitrogen-fixing symbiosis with many species of the large legume genus
Mimosa
as well as with common bean (
Phaseolus vulgaris
L.).
Paraburkholderia
are considered to have evolved nodulation independently from the well-studied α-proteobacteria symbionts of legumes. However, the detailed mechanisms important for β-rhizobia-legume symbiosis have not yet been determined. In this manuscript, we have sequenced the genome of
P. phymatum
MP20, a strain isolated from
Mimosa pudica
nodules, and utilized transposon mutagenesis to identify a mutant that showed delayed and ineffective nodulation of
M. pudica
. Further analysis revealed that the mutant strain produced an altered lipopolysaccharide lacking rhamnose containing O-antigen. Complementation with the wild-type gene restored the symbiosis. Microscopic analysis of the ineffective nodules showed that the mutant strain did not infect the cortical cells but was restricted to the endodermis. The results suggest that the O-antigen of
P. phymatum
is important for the bacterial infection of cortical cells and for nodule maturation. Further research will unveil the specific involvement of the glycosyltransferase gene in LPS biosynthesis and its impact on successful nodule formation by
P. phymatum
.

IMPORTANCE

The nitrogen-fixing symbiosis between legumes and rhizobia is important for agricultural and environmental sustainability. The mechanisms of the symbiotic interactions are extensively studied using α-rhizobia. In contrast, mechanisms of symbiotic interactions important for β-rhizobia and their Caesalpinioid (mimosoid) legume hosts are not well known. Here, we describe the genome sequence of
P. phymatum
MP20
,
a β-rhizobia isolated from the nodules of
M. pudica,
and isolation and characterization of a transposon mutant defective in symbiosis. We demonstrate that the O-antigen of the LPS is required for nodulation and symbiotic nitrogen fixation. This study broadens our knowledge of symbiotic interactions in β-rhizobia and will lead to a better understanding of the wider rhizobial-legume symbiosis apart from the α-rhizobia.
Evaluation of long-read sequencing for Ostreid herpesvirus type 1 genome characterization from
Magallana gigas
infected tissues
Authors: Dotto-Maurel Aurélie , Pelletier Camille , Degremont Lionel , Heurtebise Serge , Arzul Isabelle , Morga Benjamin , Chevignon Germain
Published: January 2025

Since the 1990s, the Pacific oyster
Magallana gigas
has faced significant mortality, which has been associated with the detection of the Ostreid Herpesvirus type 1 (OsHV-1). Due to the complex genomic architecture and the presence of multiple genomic isomers, short-read sequencing using Illumina method struggles to accurately assemble tandem and repeat regions and to identify and characterize large structural variations in the OsHV-1 genome. Third-generation sequencing technologies, as long-read real-time nanopore sequencing from Oxford Nanopore Technologies (ONT), offer new possibilities for OsHV-1 whole-genome analysis. Identification of the best method for extraction of high molecular weight (HMW) DNA and development of accurate bioinformatic pipelines for its characterization are now required. To this end, we evaluated and compared six HMW methods and one conventional DNA extraction kit for their ability to extract OsHV-1 DNA from
M. gigas
-infected tissues. We then evaluated the ability of ONT sequencing to produce an accurate OsHV-1 genome from both whole-genome and “adaptive sampling” (AS) sequencing approaches. Finally, we evaluated the efficiency of bioinformatics tools for
de novo
assembly and consensus calling to generate accurate OsHV-1 genomes. The HMW DNA extraction kit coupled with ONT sequencing and dedicated bioinformatics tools allowed us to produce accurate OsHV-1 genomes compared to those assembled using Illumina technology. The AS approach allowed up to 60% enrichment for viral data, and the long reads generated by ONT allowed the characterization of OsHV-1 isomers. Together with its portability, this sequencing shows great promise as a diagnostic tool for the characterization of unculturable aquatic viruses directly from host tissues.

IMPORTANCE

Many aquatic viruses threaten commercially valuable species and cause significant economic losses during outbreaks. To improve our understanding of the origin, transmission patterns and spread of these viruses, additional genomic data are essential. However, genomic characterization of unculturable large DNA viruses is a major challenge. In the present study, we have successfully evaluated the ability of ONT sequencing and adaptive sequencing (AS) to sequence and assemble the complete OsHV-1 genome. Our results show that it is now possible to sequence the whole genome of large DNA viruses directly from infected host tissue, without the need for prior
in vitro
propagation or prior laboratory steps for virus enrichment.
Cardiac Lymph Flow Features and New Opportunities for Their Experimental Visualization
Authors: Iablonskii P. P. , Lazareva A. S. , Garapach I. A. , Iablonskaia A. A. , Orlov S. V.
Published: January 2025

The aim of this study was to describe the features of myocardial lymph flow using a new combined method of visualization of the lymphatic system. The study was performed on pig hearts harvested from a local slaughterhouse. The original dye, consisting of lipid-soluble chlorophyll and lipiodol, was injected stepwise into the lymphatic vessels. After sufficient optical identification of the lymphatic vessels, continuous injection of air into the coronary arteries was performed and CT scans were done. In this way, both optical and radiologic visibility of the cardiac lymphatic system was achieved. It was shown that lymph flow of the left and most part of the right ventricle is carried out through lymphatic collectors of the anterior wall of the heart, including retrogradely with respect to the right coronary artery, which complements the previously known facts about the structure of the lymphatic system of the heart.
Dapagliflozin plus calorie restriction for remission of type 2 diabetes: multicentre, double blind, randomised, placebo controlled trial
Authors: Liu Yuejun , Chen Ying , Ma Jianhua , Lin Jiayang , Liu Changqin , Li Xuejun , Xu Yong , Kuang Hongyu , Shi Lixin , Xue Yaoming , Feng Bo , Zhu Dalong , Wang Guang , Yang Jinkui , Xiao Xinhua , Yu Xuefeng , Zhou Jiaqiang , Bao Yuqian , Su Qing , Lyu Minzhi , Li Xiaomu , Zhang Huijie , Li Xiaoying
Published: January 2025

Objective

To assess the effect of dapagliflozin plus calorie restriction on remission of type 2 diabetes.

Design

Multicentre, double blind, randomised, placebo controlled trial.

Setting

16 centres in mainland China from 12 June 2020 to 31 January 2023.

Participants

328 patients with type 2 diabetes aged 20-70 years, with body mass index >25 and diabetes duration of <6 years.

Interventions

Calorie restriction with dapagliflozin 10 mg/day or placebo.

Main outcome measures

Primary outcome: incidence of diabetes remission (defined as glycated haemoglobin <6.5% and fasting plasma glucose <126 mg/dL in the absence of all antidiabetic drugs for at least 2 months); secondary outcomes: changes in body weight, waist circumference, body fat, blood pressure, glucose homoeostasis parameters, and serum lipids over 12 months.

Results

Remission of diabetes was achieved in 44% (73/165) of patients in the dapagliflozin group and 28% (46/163) of patients in the placebo group (risk ratio 1.56, 95% confidence interval (CI) 1.17 to 2.09; P=0.002) over 12 months, meeting the predefined primary endpoint. Changes in body weight (difference −1.3 (95% CI −1.9 to −0.7) kg) and homoeostasis model assessment of insulin resistance (difference −0.8, −1.1 to −0.4) were significantly greater in the dapagliflozin group than in the placebo group. Likewise, body fat, systolic blood pressure, and metabolic risk factors were significantly more improved in the dapagliflozin group than in the placebo group. In addition, no significant differences were seen between the two groups in the occurrence of adverse events.

Conclusion

The regimen of dapagliflozin plus regular calorie restriction achieved a much higher rate of remission of diabetes compared with calorie restriction alone in overweight or obese patients with type 2 diabetes.

Trial registration

ClinicalTrials.gov
NCT04004793
.