jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Boyan Dochev | Sabi Sabev | Plamen Kasabov | Desislava Dimova
Source: AIP conference proceedings (article, 2024-01-01)
Field: Materials Science — General Materials Science

Investigation of the influence of the microstructure of AlSi25Cu4Cr and AlSi25Cu5Cr alloys on the roughness class in machining The hypereutectic aluminum-silicon alloys AlSi25Cu4Cr and AlSi25Cu5Cr were modified with different concentrations of phosphorus – 0.04%, 0.06%, 0.08% and 0.1%. What was determined was the concentrations of the modifier phosphorus with which structures ensuring increased mechanical characteristics of the Rm with copper alloys AlSi25Cu4Cr and AlSi25Cu5Cr before being subjected to thermic processing. The volume of the used modifier in the presence of which a premodification of the structure of the testing alloys is present, which leads to the reduction of their impact strength, was experimentally defined. The influence of the final structure of the alloys on the roughness grade of the surfaces was studied during mechanical processing. It was determined that the alloys with the maximum modified effect have the highest amount of Ra after lathing. Machining ; Microstructure ; Surface roughness ; Materials science ; Surface finish ; Metallurgy ; Class (philosophy) ; Mechanical engineering ; Engineering drawing ; Computer science ; Engineering ; Composite material ; Artificial intelligence Material Properties and Applications ; Additive Manufacturing and 3D Printing Technologies ; Aluminum Alloy Microstructure Properties
Authors: Huan Yang | Umberto Raucci | Siddharth Iyer | Galib Hasan | Thomas Golin Almeida | Shawon Barua | Anni Savolainen | Juha Kangasluoma | Matti Rissanen | Hanna Vehkamäki | Theo Kurtén
Source: ChemRxiv (preprint, 2024-07-01)
Field: Chemistry — Physical and Theoretical Chemistry

Unveiling an Unexpected Branching Point in α-pinene Ozonolysis via Molecular Dynamics Guided Reaction Discovery Secondary organic aerosols (SOAs) significantly impact Earth’s climate and human health. Although the oxidation of volatile organic compounds (VOCs) has been recognized as the major contributor to the atmospheric SOA budget, the mechanisms by which this process produces SOA-forming highly oxygenated organic molecules (HOMs) remain unclear. A major challenge is navigating the complex chemical landscape of these transformations, which traditional hypothesis-driven methods fail to thoroughly investigate. Here, we explored the oxidation of α-pinene, a critical atmospheric biogenic VOC, using a novel reaction discovery approach based on ab initio molecular dynamics and state-of-the-art enhanced sampling techniques. Our approach successfully identified all established reaction pathways of α-pinene ozonolysis, as well as discovered multiple novel species and pathways without relying on a priori chemical knowledge. In particular, we unveiled an unexpected branching point that leads to the rapid formation of alkoxy radicals, whose high and diverse reactivity help to explain hitherto unexplained oxidation pathways suggested by mass spectral peaks observed in α-pinene ozonolysis experiments. This branching point is likely prevalent across a variety of atmospheric VOCs and could be crucial in establishing the missing link to SOA-forming HOMs. Ozonolysis ; Branching (polymer chemistry) ; Pinene ; Chemistry ; Organic chemistry Chemical Reactions and Mechanisms ; Electrochemical Analysis and Applications ; Photochemistry and Electron Transfer Studies
Authors: Zhibin Wu | Chi Chen | F.-J. CHEN | Yijie Liu
Source: International Journal of Aerospace Engineering (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Damage and Failure of Aeroengine Blades Under Small UAV Impacts Unmanned aerial vehicles (UAVs) may collide with vulnerable parts of other aircrafts, such as engine blades, causing accidents. The research on small UAV impact is limited. Besides, UAV impact with propeller and rotor blades is poorly understood. In this paper, a finite element (FE) model of a UAV with a weight of 4.78 kg, turbofan blades, propeller blades, and helicopter tail rotor blades was developed. The FE modelling was carried out by commercial software named LS‐DYNA R13.1.0, which is one of the most advanced simulation tools for nonlinear dynamic structural analysis, mainly solving numerical simulations of collision and penetration problems. First, the UAV FE model was validated by comparing the simulation results against the experiments. Next, simulations were conducted to investigate the damage of the three blades under UAV impact with different heading angles. The damage type and effect of UAV’s heading angle were analyzed and identified. The simulation results indicated that the turbofan blades experienced the more severe damage, compared with the propeller blades and tail rotor blades. The head orientation of the UAV has a significant effect on the impact force of the three aircraft engine blades. In addition, certain parts of the UAV (e.g., battery) can produce significant damage to the blades. The research findings are helpful for the safety assessment of the UAV impact damages to different aircraft engines. Forensic engineering ; Aerospace engineering ; Engineering ; Aeronautics High-Velocity Impact and Material Behavior ; Structural Response to Dynamic Loads ; Transportation Safety and Impact Analysis
Authors: Agata Kołodziejczyk | M. Silarski | Mateusz Kaczmarek | M. Harasymczuk | Katarzyna Dziedzic-Kocurek | Tadeusz Uhl
Source: Research Square (preprint, 2024-04-17)
Field: Materials Science — Materials Chemistry

Radioprotective properties of the kombucha-derived bacterial cellulose Cellulose ; Chemistry ; Bacterial cellulose ; Biofilm ; Biocompatibility ; Bacteria ; Chemical engineering ; Food science ; Biochemistry ; Organic chemistry Radiation Shielding Materials Analysis ; Radioactivity and Radon Measurements ; Heavy Metals in Plants
Authors: Huan Yang | Umberto Raucci | Siddharth Iyer | Galib Hasan | Thomas Golin Almeida | Shawon Barua | Anni Savolainen | Juha Kangasluoma | Matti Rissanen | Hanna Vehkamäki | Theo Kurtén
Source: ChemRxiv (preprint, 2024-07-04)
Field: Chemistry — Physical and Theoretical Chemistry

Unveiling an Unexpected Branching Point in α-pinene Ozonolysis via Molecular Dynamics Guided Reaction Discovery Secondary organic aerosols (SOAs) significantly impact Earth’s climate and human health. Although the oxidation of volatile organic compounds (VOCs) has been recognized as the major contributor to the atmospheric SOA budget, the mechanisms by which this process produces SOA-forming highly oxygenated organic molecules (HOMs) remain unclear. A major challenge is navigating the complex chemical landscape of these transformations, which traditional hypothesis-driven methods fail to thoroughly investigate. Here, we explored the oxidation of α-pinene, a critical atmospheric biogenic VOC, using a novel reaction discovery approach based on ab initio molecular dynamics and state-of-the-art enhanced sampling techniques. Our approach successfully identified all established reaction pathways of α-pinene ozonolysis, as well as discovered multiple novel species and pathways without relying on a priori chemical knowledge. In particular, we unveiled an unexpected branching point that leads to the rapid formation of alkoxy radicals, whose high and diverse reactivity help to explain hitherto unexplained oxidation pathways suggested by mass spectral peaks observed in α-pinene ozonolysis experiments. This branching point is likely prevalent across a variety of atmospheric VOCs and could be crucial in establishing the missing link to SOA-forming HOMs. Ozonolysis ; Branching (polymer chemistry) ; Pinene ; Chemistry ; Organic chemistry Chemical Reactions and Mechanisms ; Electrochemical Analysis and Applications ; Photochemistry and Electron Transfer Studies
Authors: Adrien Delpoux | Sijia Ran | A. Claverie | Daniel L. Benoit | J. Grisolia
Source:  (article, 2024-06-30)
Field: Materials Science — Materials Chemistry

Study of Intermediate States of Ge-Rich GeSbTe Phase Change Memories by Impedance Spectroscopy We propose a first investigation of intermediate resistance states of Ge-rich GST (GGST) PCMs by impedance spectroscopy. We highlight that all states present resistive and capacitive components. When switching the memory from the RESET to the SET state the resistance decreases continuously from a low resistance state to a high resistance state while we observe the opposite behavior for the capacitance values. Based on these results, we propose to redefine a state by considering not only the resistance but also the capacitance of the device. Materials science ; Phase-change memory ; Phase change ; Dielectric spectroscopy ; Spectroscopy ; Phase (matter) ; Optoelectronics ; Engineering physics ; Chemistry ; Physics ; Physical chemistry ; Electrode Phase-change materials and chalcogenides ; Chalcogenide Semiconductor Thin Films ; Nonlinear Optical Materials Studies
Authors: Ebru Öztürkmen | Cem Güneşoğlu | Mehmet Topalbekiroğlu
Source: Fibres and Textiles in Eastern Europe (article, 2024-08-01)
Field: Materials Science — Polymers and Plastics

Investigating the Effects of PU-Based Back-Coating with Boric Acid and Titanium Dioxide Additives on Flame Retardancy Levels and Comfort Properties of 100% Cotton Denim Fabric Abstract This study aimed to develop a cost-effective and resource-efficient application to enhance the thermal stability, flame retardancy, self-cleaning, and antibacterial properties of cotton denim fabrics through a single-step, flexible, and simple polyurethane (PU) based back-coating method, ultimately increasing the use of denim fabrics in daily and work clothes thanks to the increased functionality. This method utilizes boric acid (H 3 BO 3 ) and a binary composite of H 3 BO 3 -titanium dioxide (TiO 2 ) as functional additives while considering comfort parameters. Limiting oxygen index (LOI) and vertical burning tests were conducted to explore the thermal stability and flame retardancy of the samples, while assessments of air permeability, water vapour permeability, thermal resistance, and thermal absorptivity were performed to investigate the comfort properties. Comparing two kinds of back-coated denim fabrics, H 3 BO 3 -TiO 2 back-coated cotton fabric showed the best flame retardancy with the lowest char length (45 mm) and highest LOI (27%). The air permeability values of back-coated fabrics decreased by approximately half compared to the untreated denim fabric. Although the water vapour permeability values decreased, they were less affected by the coating. Coating application reduced thermal conductivity and thermal absorbency, resulting in more thermally resistant denim fabric. This study demonstrates the potential utility of a PU-based coating incorporating TiO 2 and H 3 BO 3 on traditional cotton denim fabrics to enhance flame resistance while minimizing any adverse effects on the overall thermal comfort of the fabric. Denim ; Boric acid ; Titanium dioxide ; Coating ; Materials science ; Composite material ; Chemistry ; Organic chemistry Flame retardant materials and properties ; Polymer composites and self-healing ; Dyeing and Modifying Textile Fibers
Authors: Jie Wang | Dongyan Shi | Xianxun Yao | Zhiwei Wang
Source:  (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Research on similarity law of nonlinear shock response of ship plate frame structure under underwater explosion The anti-explosion ability of ship grillage structure is an important index to evaluate the vitality of ships. Its model test is a low-cost and effective method to evaluate the vitality of ships and guide the design of ship anti impact structures. In view of the nonlinear and nonstationary process of underwater explosion damage to ship grillage, this paper breaks through the nonlinear effect of transient explosion impact that is not considered in the traditional scale model design, focuses on the one-dimensional nonlinear impact response of ship grillage structure, and carries out the characterization study of the similarity between model experiments and real ships. Considering that the vertical motion of the prototype and the model grillage structure in the model test obey the random walking model, the vertical impact response of the deck grillage is characterized as one-dimensional nonlinear non-stationary Brownian motion, which is described by Hurst index. Based on the classical similarity law, the similarity transformation relationship between the range R and the mean square deviation S is derived, and the Hurst index of the model and the prototype meets the equal relationship; Take a section of grillage structure on a real ship and conduct prototype, 1/2, 1/3, 1/4 and 1/5 one-dimensional nonlinear explosion impact scale simulation tests respectively. The numerical response results show obvious nonlinear characteristics, and the Hurst index of displacement, velocity and acceleration response of the model within the pulse width range is less than 5% compared with the prototype. According to the scale invariance of fractional Brownian motion, the similarity conversion relationship of multiple parameters (displacement, velocity, acceleration and mean square response) is obtained. With the mean square response as the characteristic parameter, the response value of the prototype is converted through this relationship, and compared with the model simulation results, the multi parameter response error under each scale ratio is less than 20%. It provides theoretical and technical support for conducting similar experiments on nonlinear response of underwater explosion shock of ships Underwater explosion ; Nonlinear system ; Underwater ; Shock (circulatory) ; Similarity (geometry) ; Frame (networking) ; Computer science ; Structural engineering ; Geology ; Marine engineering ; Law ; Engineering ; Artificial intelligence ; Physics ; Oceanography ; Political science ; Telecommunications Ultrasound and Cavitation Phenomena
Authors: Siyu Lu | Jixiang Zhang | Min Xi | Nian Li | Zhenyang Wang
Source: arXiv (Cornell University) (preprint, 2024-10-30)
Field: Materials Science — Surfaces, Coatings and Films

3D Printable Plasmonic Titanium Nitride Nanoparticles Enhanced Thermoplastic Polyurethane Composite for Improved Photothermal De-Icing and Infrared Labeling Plasmonic nanomaterials offer a direct and effective approach to harnessing solar energy. Specifically, plasmonic semiconductors enable a highly efficient light-to-heat conversion process, outperforming noble metals in stability, cost-effectiveness, and accessibility. In this study, a composite 3D printing filament (T-TPU), composed of titanium nitride (TiN) and thermoplastic polyurethane (TPU), was synthesized using a combined extrusion process involving a twin-screw extruder and a single-screw extruder. The resulting T-TPU filament could be used with fused deposition modeling (FDM) 3D printing to produce custom-designed patterns. Notably, these printed patterns exhibited superior photothermal performance, with potential applications in photothermal de-icing and infrared labeling. Additionally, the wavelength-dependent plasmonic and photothermal responses of the printed patterns were experimentally investigated and supported by finite elemental method (FEM) simulations, revealing a temperature increase of approximately 2.5 under IR LED light when compared to commercial black thermoplastic polyurethane (C-TPU), that was more obvious than a difference less than 1 under UV or visible LED light sources. Finally, the mechanical properties of T-TPU, altered by the inclusion of TiN nanoparticles, were assessed, showing a slight enhancement in modulus and friction coefficient relative to neat TPU (N-TPU). Molecular dynamics (MD) simulations indicated that the TiN nanoparticles promoted strong interactions between polymer chains and TiN particles, enhancing the modulus of elasticity and contributing to the improved mechanical properties of T-TPU. These findings suggest improved abrasion resistance, demonstrating the stability and durability of the composite material. Materials science ; Photothermal therapy ; Photothermal effect ; Composite number ; Thermoplastic polyurethane ; Polyurethane ; Nanoparticle ; Nitride ; Titanium ; Icing ; Infrared ; Composite material ; Plasmon ; Nanotechnology ; Optoelectronics ; Elastomer ; Optics ; Metallurgy ; Layer (electronics) Surface Modification and Superhydrophobicity
Authors: Mohd Khairul Domadi | Mohd Idris Shah Ismail | Mohd Hanif Mohd Pisal | M.Y.M. Zuhri | Abdul Rahim Kassim
Source: AIP conference proceedings (article, 2024-01-01)
Field: Materials Science — Polymers and Plastics

Laser cutting process of natural polymer composites: Scope, limitation, and application The environmental concern with global Sustainable Development Goals (SDGs) has given researchers and industries more attention to using renewable resources and eco-friendly composite materials. However, conventional machining methods have drawbacks when machining natural composite materials. As a promising unconventional method, laser cutting has attracted the attention of manufacturing industries to machining composites, including natural fiber-reinforced polymer composites (NFRCs). Natural polymer composite materials, particularly those that use natural fibers as fillers, are trendy in a wide range of engineering applications. The challenge of this nontraditional method with NFRCs required the industries to demand extensive research into composite materials cutting properties and laser mechanisms. Using a long-pulse laser beam for cutting causes thermal effects during the material removal process. These effects include melting zones, heat-affected zones (HAZ), recast layers, and thermal damage to neighboring layers. This paper focuses on the overview of the laser machining concept in laser cutting processes and their advantages in cutting NFRCs. The final product applications of the NFRCs determine the laser machining strategies. The laser cutting performance analysis associated with machining challenges and essential process parameters that affect the cutting kerf quality and the HAZ is outlined for a better fundamental understanding in this research area. Future research into laser cutting mechanisms on NFRCs could benefit from new combinations of laser type, process parameters, and selected composition of NFRCs. Materials science ; Scope (computer science) ; Laser ; Process (computing) ; Composite material ; Polymer ; Laser cutting ; Natural (archaeology) ; Computer science ; Optics ; Geology ; Physics Natural Fiber Reinforced Composites ; Polymer composites and self-healing ; Plant-Derived Bioactive Compounds
Authors: Jie Wang | Dongyan Shi | Xianxun Yao | Zhiwei Wang
Source:  (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Research on similarity law of nonlinear shock response of ship plate frame structure under underwater explosion The anti-explosion ability of ship grillage structure is an important index to evaluate the vitality of ships. Its model test is a low-cost and effective method to evaluate the vitality of ships and guide the design of ship anti impact structures. In view of the nonlinear and nonstationary process of underwater explosion damage to ship grillage, this paper breaks through the nonlinear effect of transient explosion impact that is not considered in the traditional scale model design, focuses on the one-dimensional nonlinear impact response of ship grillage structure, and carries out the characterization study of the similarity between model experiments and real ships. Considering that the vertical motion of the prototype and the model grillage structure in the model test obey the random walking model, the vertical impact response of the deck grillage is characterized as one-dimensional nonlinear non-stationary Brownian motion, which is described by Hurst index. Based on the classical similarity law, the similarity transformation relationship between the range R and the mean square deviation S is derived, and the Hurst index of the model and the prototype meets the equal relationship; Take a section of grillage structure on a real ship and conduct prototype, 1/2, 1/3, 1/4 and 1/5 one-dimensional nonlinear explosion impact scale simulation tests respectively. The numerical response results show obvious nonlinear characteristics, and the Hurst index of displacement, velocity and acceleration response of the model within the pulse width range is less than 5% compared with the prototype. According to the scale invariance of fractional Brownian motion, the similarity conversion relationship of multiple parameters (displacement, velocity, acceleration and mean square response) is obtained. With the mean square response as the characteristic parameter, the response value of the prototype is converted through this relationship, and compared with the model simulation results, the multi parameter response error under each scale ratio is less than 20%. It provides theoretical and technical support for conducting similar experiments on nonlinear response of underwater explosion shock of ships Underwater explosion ; Underwater ; Nonlinear system ; Shock (circulatory) ; Similarity (geometry) ; Frame (networking) ; Structural engineering ; Law ; Computer science ; Geology ; Marine engineering ; Engineering ; Physics ; Artificial intelligence ; Political science ; Oceanography ; Telecommunications ; Image (mathematics) Ultrasound and Cavitation Phenomena
Authors: Vishnu Soman | Maneesh Kumar Poddar
Source: Research Square (preprint, 2024-01-09)
Field: Materials Science — Biomaterials

Utilizing Anthocyanin Incorporated Chitosan-Neem Gum Nanocomposites for Smart and Active Food Packaging Solutions Abstract The present work explores the potential of chitosan-neem gum nanocomposite films for potential application in active and smart food packaging. The incorporation of anthocyanin pigment allows consumers to visually assess the spoilage of packaged food. Scanning electron microscopy (SEM) analysis reveals a uniform structure and even nanoclay dispersion in cross-linked films, highlighting the effectiveness of ultrasound in dispersing components within the matrix. Fourier-transform infrared spectroscopy (FTIR) confirms successful cross-linking of chitosan and neem gum. Thermogravimetric analysis (TGA) demonstrates improved thermal stability in cross-linked films, a valuable trait for thermal sensitive packaging. Tensile testing indicates that neem gum content influences film flexibility, while cross-linking enhances strength and rigidity. The reduced water vapor permeability in cross-linked films extends shelf life. Swelling index data suggests film stability, and antimicrobial assays underline the potential for further optimization. This research highlights the promise of anthocyanin-incorporated chitosan-neem gum nanocomposite films in food packaging with significant scope for further developments. Chitosan ; Materials science ; Thermogravimetric analysis ; Thermal stability ; Active packaging ; Nanocomposite ; Food packaging ; Fourier transform infrared spectroscopy ; Anthocyanin ; Ultimate tensile strength ; Chemical engineering ; Composite material ; Food science ; Chemistry Nanocomposite Films for Food Packaging ; Natural Fiber Reinforced Composites ; Lignin and Wood Chemistry