jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Balasaheb J. Nagare | Sajeev Chacko | D. G. Kanhere
Source: Physica Scripta (article, 2024-03-25)
Field: Materials Science — Materials Chemistry

Machine-Learned Potential Energy Surfaces for Free Sodium Clusters with Density Functional Accuracy: Applications to Melting Abstract Gaussian Process Regression based Gaussian Approximation Potential has been used to develop machine learned interatomic potentials having density functional accuracy, for free sodium clusters. The training data was generated from a large sample of over 100,000 data points computed for clusters in the size range of N = 40–200, where N denotes the number of atoms in the cluster, using the density functional method as implemented in the VASP code. Two models have been developed, model M1 using data for N = 55 only, and model M2 using additional data from larger clusters. The models are intended for computing thermodynamic properties using molecular dynamics. Hence, particular attention has been paid to improve the fitting of the forces. Although it was possible to obtain a good fit using the data of Na 55 only, additional data points from larger clusters were needed to get better accuracies in energies and forces for larger sizes. Surprisingly, the model M1 could be significantly improved by adding about 50 data points per cluster from the larger sizes. Thus, it turns out that the best fit can be obtained by carefully selecting a small number of data points viz . 1,900 and 1,300 configurations for the two models M1 and M2, respectively. These two models have been deployed to compute the heat capacities of Na 55 . The heat capacities of Na 147 and about 40 isomers for larger clusters of sizes N = 147, 200, 201, and 252, have been obtained using the final model M2. There is an excellent agreement between the computed and experimentally measured melting temperatures. The geometries of these isomers have been further optimized by density functional theory. The mean absolute error with respect to DFT energies is found to be about 7 meV/atom or less. The errors in the lowest interatomic bond lengths are below 2% in almost all the cases. Energy (signal processing) ; Materials science ; Density functional theory ; Computer science ; Sodium ; Energy density ; Statistical physics ; Engineering physics ; Physics ; Quantum mechanics Machine Learning in Materials Science ; Inorganic Chemistry and Materials ; X-ray Diffraction in Crystallography
Authors: Chenchen Gao | Aitang Xing | Zhiqi He | Peichen Yuan | Yajing Qiao | Xiaoyu Li
Source: Journal of Polymer Science (article, 2024-12-16)
Field: Materials Science — Polymers and Plastics

A Novel Schiff Base Epoxy: Synthesis, Degradability, and Application as a MultiPurpose Modifier for <scp>DGEBA</scp>/<scp>DDM</scp> ABSTRACT Simultaneously increasing mechanical strength, toughness, thermal stability, and flame retardancy of epoxy thermoset without compromising transparency is appealing but challenging. To address that goal, a Schiff base epoxy VDEP is developed. The neat VDEP‐cured product, VDEP 100wt% , not only shows comparable mechanical strength to conventional epoxy thermoset but also can be degraded in 10% H 2 SO 4 /THF/H 2 O solution in 24 h, showing great degradability under mild conditions. More importantly, proper addition of VDEP simultaneously increases the tensile strength, impact strength, T g , T d5% , char residue, and UV shielding of cured epoxies while providing self‐extinguishing ability. All of those enhancements are achieved without deteriorating transparency. When 15 wt% of VDEP is added, the tensile strength reaches 91.07 MPa, with a 36.7% increase; the impact strength reaches 40.73 kJ m −2 , with a 33.8% increase. The enhancement in mechanical strength is due to the reinforcing effect of intermolecular interaction and compacted network caused by free volume reduction. The higher toughness results from greater mobility of chain segments, reduced crosslinking density and energy dissipative intermolecular interaction. The rigid two benzene‐conjugated Schiff base structure and abundant hydrogen bonding contribute to higher T g . Therefore, this work provides a degradable Schiff base epoxy and high‐performance thermoset based on it. Epoxy ; Schiff base ; Chemistry ; Polymer chemistry ; Organic chemistry Synthesis and properties of polymers ; Epoxy Resin Curing Processes ; Polymer crystallization and properties
Authors: Sai Zhong | Yuxuan Xue | Kuanwen Wang | Haoyang Li | Yanghua Lu | Zhenqian Pang | Tengyao Jiang | Gang Tan
Source: National Science Open (article, 2024-03-12)
Field: Materials Science — Polymers and Plastics

pH-sensitive tunable thermochromic hydrogel with carbon quantum dots for smart windows Thermoresponsive hydrogels have been designed for smart windows to dynamically modulate solar radiation but the inherent defects of long response time and the imperfectly matched phase transition temperature have limited wide applications. This work reports a novel composite hydrogel consisting of hydroxypropyl cellulose, polyacrylic acid and carbon quantum dots with intriguing features of tunable transition temperature and enhanced switching speed. The adjustable transition temperature demonstrated flexible tunability by controlling the hydrogen ion concentration and a fast response speed by dopped with carbon dots for efficient photothermal conversion. The building energy simulation was carried out to investigate the impacts of transition temperature variations and solar regulations on the space cooling/heating loads under different climate conditions, revealing the necessity of tunability of both transition temperature and solar transmittance in thermochromic smart windows. This novel design of thermochromic composite hydrogel provides an insight of theoretical and experimental support to future adaptive building envelope. Thermochromism ; Materials science ; Transmittance ; Optoelectronics ; Composite number ; Photothermal therapy ; Glazing ; Self-healing hydrogels ; Nanotechnology ; Composite material ; Polymer chemistry ; Chemistry Transition Metal Oxide Nanomaterials ; Aerogels and thermal insulation ; Urban Heat Island Mitigation
Authors: Pengpeng Yang | Qian Wu | Haodong Liu | Shuyang Zhou | Wensu Chen | Huamei Zhong | Keke Zhang | Fengxia Zou | Hanjie Ying
Source: Ultrasonics Sonochemistry (article, 2024-06-12)
Field: Materials Science — Materials Chemistry

Simulation and mechanism for the Ultrasound-Assisted Oiling-Out Process: A case study using Fructose-1,6-diphosphate Liquid-liquid separation, commonly referred to as oiling-out, frequently can occurs during crystallization, especially the anti-solvent crystallization process of phosphoryl compounds, and poses potential hurdle for high-quality product. Efficiently regulating oiling-out during crystallization remains a significant challenge. Among various techniques, ultrasound emerges as a green and effective approach to enhance the crystallization process. However, there is a dearth of in-depth research exploring the microscopic mechanisms of this process. Therefore, our research focused on the fructose-1,6-diphosphate (FDP), a typical phosphoryl compound, to gain a deeper understanding of how ultrasound influences the oiling-out process. The focused beam reflectance measurement (FBRM) technology was used to investigate the oiling-out phenomenon of FDPNa<sub>3</sub> across various solvent ratios. In addition, the influence of ultrasound on the induction time was studied and the nucleation energy barrier was calculated. Finally, to further unravel the microscopic mechanisms, we utilized molecular simulation techniques to analyze the impact of ultrasound power on the dissolution-precipitation process. Our observations revealed a consistent oiling-out process that attainted a stable state regardless of the solvent employed. Notably, the results of the oiling-out induction time experiments indicated that ultrasound significantly reduced helped lower the nucleation energy barrier of FDP<sup>3-</sup> ions, thereby dismantling FDP<sup>3-</sup>clusters in solution. Thus, in turn, shortened the reduced induction time and promoted crystallization. Furthermore, ultrasound reduced the interactions between FDP<sup>3-</sup>ions and water molecules as well as FDP<sup>3-</sup> ions themselves. As simulated field intensity increased, these interaction forces gradually diminished, the thickness of the hydration layer surrounding the FDP<sup>3-</sup> clusters facilitating the disruption of clusters, ultimately enhancing the crystallization process. Crystallization ; Process (computing) ; Ultrasound ; Chemical engineering ; Chemistry ; Process engineering ; Materials science ; Pulp and paper industry ; Computer science ; Organic chemistry ; Physics Crystallization and Solubility Studies ; Freezing and Crystallization Processes ; Enzyme Structure and Function
Authors: Makoto Sakurai
Source: Chemical Synthesis (article, 2024-08-01)
Field: Materials Science — Materials Chemistry

On-surface synthesized magnetic nanoclusters of ferrocene derivatives On-surface molecular self-assembly in solution can produce two-dimensional (2D) materials with unique surface nanostructures that have the potential to create new functionalities. The surface completely differs from the uniform flat surface of conventional 2D materials such as graphene, MoS2, and 2D van der Waals nanosheets. The recently developed on-surface chemical synthesis of amino-ferrocene (AFc) nanoclusters on a graphene oxide (GO) nanosheet is a technique based on molecular self-assembly. Here, this method is applied to other ferrocene derivatives whose ferrocene units are covalently bonded to an amino group and several other molecules. The structure of the on-surface synthesized nanoclusters is analyzed by high-resolution transmission electron microscopy and atomic force microscopy. The molecules in the nanoclusters are densely and regularly arranged, and the distance between the Fe ions of the constituent molecules is longer than that in the AFc nanoclusters. Band-through electron transfer occurs between the Fe ions and the GO nanosheet, generating unpaired 3d electrons whose magnetic state is in the high spin state (S = 5/2). The present study demonstrates the feasibility of the design and synthesis of functional molecular nanostructures with molecular precision by on-surface chemistry, leading to the fabrication of nanoscale building blocks with molecular precision and 2D platforms for next-generation molecular spintronic and neuromorphic devices. Nanoclusters ; Nanosheet ; Ferrocene ; Materials science ; Nanotechnology ; Graphene ; Molecule ; Nanostructure ; Scanning tunneling microscope ; Spintronics ; Unpaired electron ; Chemistry ; Ferromagnetism ; Organic chemistry ; Physical chemistry ; Physics Graphene research and applications ; Nanocluster Synthesis and Applications ; 2D Materials and Applications
Authors: Mi Li | Qiaohan Liu | Yi Zou | Jingang Wang | Chuanqiang Fan
Source: Molecules (article, 2024-07-13)
Field: Materials Science — Materials Chemistry

Thermoelectric Properties Regulated by Quantum Size Effects in Quasi-One-Dimensional γ-Graphdiyne Nanoribbons Using density functional theory combined with the first principles calculation method of non-equilibrium Green's function (NEGF-DFT), we studied the thermoelectric (TE) characteristics of one-dimensional γ-graphdiyne nanoribbons (γ-GDYNRs). The study found that the thermal conductivity of γ-GDYNRs has obvious anisotropy. At the same temperature and geometrical size, the lattice thermal conductivity of zigzag-edged γ-graphdiyne nanoribbons (γ-ZGDYNRs) is much lower than that of armchair-edged γ-graphdiyne nanoribbons (γ-AGDYNRs). We disclose the underlying mechanism for this intrinsic orientation. That is, γ-AGDYNRs have more phonon dispersion over the entire frequency range. Furthermore, the orientation dependence increases when the width of the γ-GDYNRs decreases. These excellent TE properties allow armchair-edged γ-graphdiyne nanoribbons with a planar width of 1.639 nm (γ-Z(2)GDYNRs) to have a higher power factor and lower thermal conductivity, ultimately resulting in a significantly higher TE conversion rate than other γ-GDYNR structures. Zigzag ; Condensed matter physics ; Thermal conductivity ; Phonon ; Materials science ; Thermoelectric effect ; Anisotropy ; Density functional theory ; Lattice (music) ; Physics ; Chemistry ; Optics ; Computational chemistry ; Thermodynamics ; Composite material ; Geometry Advanced Thermoelectric Materials and Devices ; Thermal properties of materials ; Graphene research and applications
Authors: Yongdan Wang | Xiangjiu Zhu | Hengshuo Zhang | Shitong He | Ying Liu | Wenshi Zhao | Huilian Liu | Xin Qu
Source: Molecules (article, 2024-07-28)
Field: Materials Science — Materials Chemistry

Janus MoSH/WSi2N4 van der Waals Heterostructure: Two-Dimensional Metal/Semiconductor Contact Constructing heterostructures from already synthesized two-dimensional materials is of significant importance. We performed a first-principles study to investigate the electronic properties and interfacial characteristics of Janus MoSH/WSi<sub>2</sub>N<sub>4</sub> van der Waals heterostructure (vdWH) contacts. We demonstrate that the p-type Schottky formed by MoSH/WSi<sub>2</sub>N<sub>4</sub> and MoHS/WSi<sub>2</sub>N<sub>4</sub> has extremely low Schottky barrier heights (SBHs). Due to its excellent charge injection efficiency, Janus MoSH may be regarded as an effective metal contact for WSi<sub>2</sub>N<sub>4</sub> semiconductors. Furthermore, the interfacial characteristics and electronic structure of Janus MoSH/WSi<sub>2</sub>N<sub>4</sub> vdWHs can not only reduce/eliminate SBH, but also forms the transition from p-ShC to n-ShC type and from Schottky contact (ShC) to Ohmic contact (OhC) through the layer spacing and electric field. Our results can offer a fresh method for optoelectronic applications based on metal/semiconductor Janus MoSH/WSi<sub>2</sub>N<sub>4</sub> vdW heterostructures, which have strong potential in optoelectronic applications. Janus ; Heterojunction ; van der Waals force ; Semiconductor ; Materials science ; Metal ; Optoelectronics ; Nanotechnology ; Condensed matter physics ; Physics ; Molecule ; Quantum mechanics ; Metallurgy 2D Materials and Applications ; MXene and MAX Phase Materials ; Graphene research and applications
Authors: Taweetham Limpanuparb | Weerapat Chiranon | Methin Intaraprasit
Source: Chemistry Teacher International (article, 2024-06-12)
Field: Chemistry — Physical and Theoretical Chemistry

Building words from chemical elements: a fun and inclusive approach to introduce the periodic table Abstract A program for writing words (or personal names) by combining chemical element symbols is developed in the context of classroom activity to introduce the periodic table, properties of elements, and periodic trends. We provide multiple examples and possible ideas to improve student engagement and create an inclusive environment in the classroom. Common confusions and mistakes made when learning the periodic table are tabulated and discussed. In addition to spelling words and creating graphics using element symbols, the program can display and print out properties of elements as part of the word-building game. Spelling ; Periodic table ; Table (database) ; Element (criminal law) ; Word (group theory) ; Computer science ; Context (archaeology) ; Graphics ; Multimedia ; Linguistics ; Computer graphics (images) ; Database Various Chemistry Research Topics ; Science Education and Pedagogy ; History and advancements in chemistry
Authors: S Sudarmin | Erna Noor Savitri | Rr. Sri Endang Pujiastuti | Sri Yamtinah | Haniza Hanim binti Mohd Zaim | Ariyatun Ariyatun
Source: Jurnal Pendidikan IPA Indonesia (article, 2024-07-03)
Field: Chemistry — Physical and Theoretical Chemistry

Reconstruction of Ethno-STEM Integrated Project Learning Models for Explanation of Scientific Knowledge Regarding Aroma Compounds of Indonesian and World Herbal Teas The background to this research is the importance of finding an integration pattern between the project learning model and Ethno-STEM based inquiry to explain scientific knowledge regarding the aroma of herbal tea. The fundamental research objective is to design an integration pattern for the project and Ethno-STEM learning model and reconstruct scientific knowledge based on public knowledge of the aromatic volatile compounds of Indonesian and world herbal teas. This research method and approach is mixed research. This qualitative approach is to find the integration of the project learning model and Ethno-STEM (Ethno-STEM PjLM) and its syntax. A quantitative approach regarding analyzing tea aroma volatile compounds using an Arduino gas sensor: research data from literature studies, interviews, reconstruction, and data on identifying volatile compounds in the aroma of herbal tea analyzed descriptively, qualitatively, and quantitatively. The results of the research concluded: (1) the reconstruction and integration pattern between PjLM Ethno-STEM is an integrated pattern with SUDARMIN syntax, (2) the reconstruction of scientific knowledge based on public knowledge regarding the process of isolation, extraction, and bioactivity of secondary metabolites, (3) herbal tea aroma volatiles compounds are identified by Arduino sensor: carbon dioxide, methane, propane, butane, acetone, alcohol, and ester, (4) the implementation of Ethno-STEM PjLM received a positive response from students. Indonesian ; Aroma ; Traditional medicine ; Food science ; Medicine ; Biology ; Philosophy Various Chemistry Research Topics ; Innovative Teaching Methods ; Higher Education and Teaching Methods
Authors: Xuanran Li | Lun Zhao | Ruijie Fei | Jincai Wang | Shanglin Liu | Minghui Li | Shujun Han | Fujian Zhou | Shuai Yuan
Source: Processes (article, 2024-02-19)
Field: Chemistry — Analytical Chemistry

Cooling Damage Characterization and Chemical-Enhanced Oil Recovery in Low-Permeable and High-Waxy Oil Reservoirs The well productivity of high-waxy reservoirs is highly influenced by temperature changes. A decrease in temperature can cause the precipitation of wax from the crude oil, leading to a decrease in the formation’s drainage capacity and a drop in oil production. In this study, the wax precipitation of crude oil is characterized by rheological properties tests and differential scanning calorimetry (DSC) thermal analysis. The wax damage characteristics of cores and the relative permeability curves at different temperatures were investigated through coreflood experiments. Furthermore, nanoemulsion is selected as a chemical agent for injection fluid. The nuclear magnetic resonance (NMR) scanning technique is used to investigate the effects of oil recovery enhancement at different pores by increasing temperature and adding nanoemulsion. By comparing the changes in T2 spectra and the distribution pattern of residual oil before and after liquid injection, the results have shown that both increasing temperature and adding nanoemulsion have a significant effect on oil recovery. The improvement of micropores is less pronounced compared to macropores. The produced oil mainly comes from the large pores. When the temperature is lower than the crude oil dewaxing point temperature, there is a serious dewaxing plugging phenomenon in the pores. Additionally, by observing the pattern of residual oil distribution at the end of the NMR online drive, it is hereby classified into wax deposition retention type, weak water washing retention type, and immobilized type, each with its own distinct characteristics. Wettability alteration and interfacial tension reduction can help to improve the drainage capacity of high-wax oil reservoirs, which is the main mechanism of nanoemulsion for enhanced oil recovery. These findings are highly valuable for enhancing the comprehension of the impact of highly waxed crude oils on drainage capacity and the ultimate oil recovery rate, particularly in relation to wax precipitation deposition. Wax ; Differential scanning calorimetry ; Residual oil ; Materials science ; Enhanced oil recovery ; Wetting ; Drop (telecommunication) ; Chemical engineering ; Chromatography ; Chemistry ; Composite material ; Organic chemistry Petroleum Processing and Analysis ; Hydrocarbon exploration and reservoir analysis ; Enhanced Oil Recovery Techniques
Authors: Mingxuan Chen | Jun Jia | Baoping Zhang | Leiyan Han | Mengbo Ji | Zhangtao Yu | Dongfang Li | Wenyong Wang | Hongjing Jia | Huachi Xu
Source: Energy Engineering (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Enhancing the Efficiency of Multi-Electrolyzer Clusters with Lye Mixer: Topology Design and Control Strategy The rise in hydrogen production powered by renewable energy is driving the field toward the adoption of systems comprising multiple alkaline water electrolyzers. These setups present various operational modes: independent ope... | Find, read and cite all the research you need on Tech Science Press Topology (electrical circuits) ; Control (management) ; Electrolysis ; Automotive engineering ; Engineering ; Computer science ; Electrical engineering ; Physics Polyoxometalates: Synthesis and Applications ; Catalysis for Biomass Conversion ; Sustainable Industrial Ecology
Authors: Frédéric Perrier | Frédéric Girault
Source: European Journal of Physics (article, 2024-01-30)
Field: Materials Science — Materials Chemistry

Two-point resistances in symmetric bracelet resistor networks: accurate estimates and exact expressions Abstract Resistor networks, used to model new types of natural or artificial matter, also provide generic examples for practising the methods of physics for obtaining estimates, revealing the main properties of a system and deriving exact expressions. Symmetric bracelet resistor networks are constructed by connecting n identical resistors in a circle, and then connecting two such circles by another set of n identical resistors. First, using van Steenwijk’s method, we establish that the equivalent resistance or two-point resistance (TPR) between any two nodes is derived when the layer-to-layer resistance R 0 n is known. We then determine R 0 n by an elementary recurrence relation which converges rapidly to its large n limit. Using this reference value of R 0 n , accurate estimates of other TPRs follow for all values of n , characterised by a leading 1/ n variation. In addition, exact explicit expressions of the TPRs can be calculated for any value of n . These networks, prototypes of three-dimensional networks considered in research, can be used to illustrate the diversity of the physical approach, the power of elementary methods, and to learn to be comfortable with approximations. Easy to make and use for experimental tests, they can support hands-on activities and conceptual changes. Physics ; Resistor ; Point (geometry) ; Theoretical physics ; Statistical physics ; Quantum mechanics ; Geometry Graphene research and applications ; Thermal properties of materials ; Topological Materials and Phenomena