jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Gulshan Kumar | Shashikant Kumar | Ajay Kumar | Prakash Parida
Source: Physical review. B./Physical review. B (article, 2024-06-03)
Field: Materials Science — Materials Chemistry

Predicting edge-localized monovacancy defects in zigzag graphene nanoribbons from Floquet quasienergy spectrum In this work we prescribe a theoretical framework aiming at predicting the position of monovacancy defects at the edges of zigzag graphene nanoribbons (ZGNRs) using Floquet-Bloch formalism, which can be experimentally observed through time- and angle-resolved photoemission spectroscopy (tr-ARPES). Our methodology involves an in-depth investigation of the Floquet quasienergy band spectrum influenced by light with varying polarization across a range of frequencies. Particularly under the influence of circularly polarized light with a frequency comparable to the bandwidth of the system, our findings suggest a promising approach for locating monovacancy defects at either edge, a challenge that proves intricate to predict from the ARPES spectrum of ZGNRs with monovacancy defects. This has been achieved by analyzing the orientation of the Floquet edge state and the appearance of new Dirac points in the vicinity of the Fermi level. The real-world applications of these captivating characteristics underscore the importance and pertinence of our theoretical framework, paving the way for additional exploration and practical use. Our approach, employing the Floquet formalism, is not limited to monovacancy-type defects; rather, it can be expanded to encompass various types of vacancy defects. Zigzag ; Graphene nanoribbons ; Enhanced Data Rates for GSM Evolution ; Floquet theory ; Spectrum (functional analysis) ; Condensed matter physics ; Graphene ; Materials science ; Physics ; Nanotechnology ; Quantum mechanics ; Mathematics ; Geometry ; Telecommunications Graphene research and applications ; 2D Materials and Applications ; Graphene and Nanomaterials Applications
Authors: Matthew D. Dickers | Gennady B. Sushko | Andrei V. Korol | N. J. Mason | Felipe Fantuzzi | Andrey V. Solov’yov
Source: The European Physical Journal D (preprint, 2024-06-01)
Field: Materials Science — Materials Chemistry

Dopant concentration effects on Si$$_{1-x}$$Ge$$_{x}$$ crystals for emerging light-source technologies: a molecular dynamics study Abstract In this study, we conduct atomistic-level molecular dynamics simulations on fixed-sized silicon-germanium (Si $$_{1-x}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>-</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> <mml:mrow/> </mml:mmultiscripts> </mml:math> Ge $$_{x}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mi>x</mml:mi> <mml:mrow/> </mml:mmultiscripts> </mml:math> ) crystals to elucidate the effects of dopant concentration on the crystalline inter-planar distances. Our calculations consider a range of Ge dopant concentrations between pure Si (0%) and 15%, and for both the optimised system state and a temperature of 300K. We observe a linear relationship between Ge concentration and inter-planar distance and lattice constant, in line with the approximation of Vegard’s Law, and other experimental and computational results. These findings will be employed in conjunction with future studies to establish precise tolerances for use in crystal growth, crucial for the manufacture of crystals intended for emerging gamma-ray crystal-based light source technologies. Graphical abstract Dopant ; Dynamics (music) ; Molecular dynamics ; Materials science ; Chemical physics ; Nanotechnology ; Crystal (programming language) ; Optoelectronics ; Crystallography ; Engineering physics ; Chemistry ; Doping ; Physics ; Computer science ; Computational chemistry Silicon Nanostructures and Photoluminescence ; Silicon and Solar Cell Technologies ; Thin-Film Transistor Technologies
Authors: Leelakrishna Reddy
Source: Journal of Fluorescence (review, 2024-02-13)
Field: Materials Science — Materials Chemistry

The Role of Anions in Rare-earth Activated Inorganic Host Materials for its Luminescence Characteristics This work is inspired from the comprehensive work done by our research team aimed at improving the efficiency of white light emitting diodes (LEDs) through improvements in the colour rendering index of the red light (CRI), one of the primary colours of white light. Such work is triggered through the incorporation of anions (BO<sub>3</sub><sup>3-</sup>, PO<sub>4</sub><sup>3-</sup>, SO<sub>4</sub><sup>2-</sup>), either individually or as an integral part of dopant activated inorganic phosphor host materials. Numerous host materials such as ZnO, Y<sub>2</sub>O<sub>3</sub>, Ca<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>, CaMoO<sub>4</sub>, ABPO<sub>4</sub>, ABSO<sub>4</sub> (where A represents alkali metals and B alkaline earth metals) have been considered ideal hosts materials for studying luminescence properties of materials (including other phosphors). In addition, red emitting dopants such as Sm<sup>3+</sup>, Eu<sup>3+</sup> and Ce<sup>3+</sup> have been incorporated into these host materials to achieve a higher CRI of red colour, an essential component of white light. The role anions in various materials is multifaceted; firstly, it acts as sensitizer whereby it absorbs excitation energy and transfers it non-radiatively to the dopants, secondly, it acts as a charge compensator to dopants with a charge of + 3, thirdly, it creates crystal fields that affects the electronic transitions of the dopants and fourthly, it creates a stable crystal structure that allows for dopant embedding. By understanding the exact role of these anions and their interactions with the host lattice and dopant ions, we could further optimize the luminescent properties of these activated host materials, which leads to higher efficiencies and performances in white light-emitting diodes and other lighting technologies. This work is a comprehensive review of the work undertaken by our research team aimed at enhancing the luminescent properties of WLEDs. Dopant ; Phosphor ; Luminescence ; Chemistry ; Light-emitting diode ; Doping ; Ion ; Optoelectronics ; Inorganic chemistry ; Chemical physics ; Nanotechnology ; Materials science ; Organic chemistry Luminescence Properties of Advanced Materials ; Gas Sensing Nanomaterials and Sensors ; Radiation Detection and Scintillator Technologies
Authors: Yong Peng | Wentao Zhou | Guang Chen | Baohong Kou | Jing Ouyang
Source: Journal of the American Ceramic Society (article, 2024-11-28)
Field: Materials Science — Ceramics and Composites

Particle size gradation design and performance enhancement of quartz cores for precision casting Abstract This study proposes an approach for the design of gradation plans via the establishment of mathematical models for particle gradation, enabling control over the particle gradation of different sizes of SiO 2 . Silica‐based ceramic cores were produced follow the above strategy for precision casting, and the impact of particle gradation and sintering regimes on the shrinkage rate and relevant mechanical properties of the silica‐based ceramic cores were investigated. The results suggest that an optimal gradation plan can effectively enhance the density of silica‐based ceramic cores, thereby influencing the shrinkage rate and mechanical properties at both room and elevated temperatures. The shrinkage rate of the silica‐based ceramic cores is influenced by the chosen gradation particle size range of the silica; the sintering regimes have notable effects on mechanical properties of the silica‐based ceramic cores. The performance data of the samples demonstrate the efficacy of applying the gradation plan to the B 60 samples with an average particle size of 60 µm in the largest grade. After undergoing a final sintering temperature at 1160°C and holding for 5 h, the shrinkage ratio could be limited to 1.33%, the room temperature bending strength reached 15.0 MPa, and the high‐temperature bending strength could be enhanced to 37.6 MPa. These findings present a significant reference values for the production of single‐crystal hollow blades. Gradation ; Materials science ; Ceramic ; Shrinkage ; Sintering ; Composite material ; Particle size ; Particle (ecology) ; Quartz ; Flexural strength ; Casting ; Mineralogy ; Chemical engineering ; Chemistry ; Computer science ; Engineering ; Geology Advanced ceramic materials synthesis ; Bone Tissue Engineering Materials ; Recycling and utilization of industrial and municipal waste in materials production
Authors: S. Chellaiya Thomas Rueshwin | R.D. Eithiraj
Source: Physica Scripta (article, 2024-11-27)
Field: Materials Science — Materials Chemistry

Structural, electronic, vibrational, optical and thermoelectric properties of 1T-Na<sub>2</sub>O monolayer via MD and DFT study Abstract Density Functional Theory (DFT) was implemented to determine the physical properties of the 1T-Na 2 O monolayer with the aid of WIEN2k software. To determine the electronic property exchange correlation such as GGA and hybrid functionals were implemented. The electronic property studies unveiled the 1T-Na 2 O monolayer as a direct bandgap semiconductor that has band gap values of 1.68 eV and 2.75 eV with GGA and hybrid correlation functionals. The dynamical stability of the 1T-Na 2 O monolayer was established by harnessing Phonon dispersion analysis, while the thermal stability was established by harnessing the Ab-initio Molecular Dynamics (AIMD). The optical properties investigation revealed that the 1T-Na 2 O monolayer shows an excellent absorption coefficient in the UV region and has a potential application in optoelectronic applications. The 1T-Na 2 O monolayer shows promise for waste heat recovery systems due to its thermoelectric properties, with a figure of merit of 0.82 at 400 K. The effective masses of electrons and holes (charge carriers) are determined. The relative ratio was estimated to determine the recombination rate of charge carriers and was found to be limited. Monolayer ; Materials science ; Thermoelectric effect ; Electronic structure ; Chemical physics ; Condensed matter physics ; Molecular physics ; Nanotechnology ; Physics ; Thermodynamics Solid-state spectroscopy and crystallography
Authors: Jianing Wang | Libo Zhang | Yepeng Xiao | Qinzhen Fan | Chong Yang | Yiqiang Deng | Hao Lü | Lihua Cheng
Source: Materials (article, 2024-04-23)
Field: Materials Science — Polymers and Plastics

Preparation of Wheat Straw Hot-Pressed Board through Coupled Dilute Acid Pretreatment and Surface Modification The production of wheat straw waste board materials encounters challenges, including inadequate inherent adhesiveness and the utilization of environmentally harmful adhesives. Employing a hot-pressed method for converting wheat straw into board materials represents a positive stride towards the resourceful utilization of agricultural wastes. This study primarily focuses on examining the influence of hot-pressing process conditions on the mechanical properties of wheat straw board materials pretreated with dilute acid. Additionally, it assesses the necessity of dilute acid treatment and optimizes the hot-pressing conditions to achieve optimal results at 15 MPa, 2 h, and 160 °C. Furthermore, a comprehensive process is developed for preparing wheat straw hot-pressed board materials by combining dilute acid pretreatment with surface modification treatments, such as glutaraldehyde, citric acid, and rosin. Finally, a thorough characterization of the mechanical properties of the prepared board materials is conducted. The results indicate a substantial improvement in tensile strength across all modified wheat straw board materials compared to untreated ones. Notably, boards treated with glutaraldehyde exhibited the most significant enhancement, achieving a tensile strength of 463 kPa, bending strength of 833 kPa, and a water absorption rate of 14.14%. This study demonstrates that combining dilute acid pretreatment with surface modification treatments effectively enhances the performance of wheat straw board materials, offering a sustainable alternative to traditional wood-based board materials. Straw ; Ultimate tensile strength ; Materials science ; Citric acid ; Hot pressing ; Absorption of water ; Composite material ; Flexural strength ; Glutaraldehyde ; Pulp and paper industry ; Chemistry ; Organic chemistry Natural Fiber Reinforced Composites ; Lignin and Wood Chemistry ; Wood Treatment and Properties
Authors: Hongyuan Zhang | Jieqiong Wang | Xiaona Ji | Yanru Bao | Ce Han | Guoying Sun
Source: Molecules (article, 2024-11-01)
Field: Materials Science — Materials Chemistry

Nitrogen and Sulfur Co-Doped Graphene-Quantum-Dot-Based Fluorescent Sensor for Rapid Visual Detection of Water Content in Organic Solvents Accurate water content detection is crucial for optimizing chemical reactions, ensuring product quality in pharmaceutical manufacturing, and maintaining food safety. In this study, nitrogen and sulfur co-doped graphene quantum dots (R-GQDs) were synthesized via a one-step hydrothermal method using o-phenylenediamine as the carbon source. The synthesis conditions, including reaction time, temperature, o-phenylenediamine concentration, and H<sub>2</sub>SO<sub>4</sub>/water ratio, were optimized using the Box-Behnken response surface methodology. The R-GQDs exhibited excellent fluorescence stability and distinct solvent-dependent characteristics, alongside a broad linear detection range and high sensitivity, making them highly suitable for dual-mode water content detection (colorimetric and fluorescent). To enhance the accuracy of visual detection, R-GQDs were incorporated into portable test strips with smartphone-assisted analysis, compensating for the human eye's limitations in distinguishing subtle color changes. The sensor's practical utility was validated through spiked recovery experiments in food samples, and the R-GQDs demonstrated good biocompatibility for in vivo imaging in shrimp. These findings highlight a novel strategy for developing portable, real-time water content sensors with potential applications in both portable detection systems and biological imaging. Graphene ; Sulfur ; Fluorescence ; Nitrogen ; Quantum dot ; Doping ; Environmental chemistry ; Chemistry ; Materials science ; Nanotechnology ; Inorganic chemistry ; Photochemistry ; Organic chemistry ; Optoelectronics ; Optics Carbon and Quantum Dots Applications ; Advanced Nanomaterials in Catalysis ; Advanced biosensing and bioanalysis techniques
Authors: Elena Yu. Tupikina | M. V. SIGALOV | Omar Alkhuder | Peter M. Tolstoy
Source: ChemPhysChem (article, 2024-04-02)
Field: Chemistry — Organic Chemistry

Charge Relay Without Proton Transfer: Coupling of Two Short Hydrogen Bonds via Imidazole in Models of Catalytic Triad of Serine Protease Active Site A homologous series of 20 substituted alcohol-imidazole-acetate model complexes imitating the charge relay system in Ser-His-Asp catalytic triad of serine proteases is considered quantum-chemically. We show qualitatively that the geometries of alcohol-imidazole and imidazole-acetate short hydrogen bonds are strongly coupled via the central imidazole and such complexes are capable of effectively relaying the charge from acetate to alcohol moiety upon relatively small concerted proton displacements. We hypothesize an alternative catalytic mechanism of serine proteases that does not require two complete proton transfers or hydrogen bond breakage between Ser and His residues. Imidazole ; Catalytic triad ; Chemistry ; Moiety ; Serine protease ; Hydrogen bond ; Serine ; Stereochemistry ; Proteases ; Alcohol ; Catalysis ; Active site ; Proton ; Photochemistry ; Protease ; Molecule ; Organic chemistry ; Enzyme Click Chemistry and Applications ; Chemical Synthesis and Analysis ; Protein Structure and Dynamics
Authors: Sean M. Edwards | Amy L. Harding | Joseph Leedale | S. David Webb | Helen Colley | Craig Murdoch | Rachel N. Bearon
Source: International Journal of Pharmaceutics (article, 2024-10-14)
Field: Chemistry — Spectroscopy

An advanced in silico model of the oral mucosa reveals the impact of extracellular spaces on chemical permeation Accurately predicting the permeation of chemicals through human epithelial tissues is crucial for pharmaceutical therapeutic design and toxicology. Current mathematical models of multi-layered stratified squamous epithelium such as those in the oral cavity use simplistic 'bricks and mortar' geometries that do not fully account for the complex cellular architecture that may affect chemical permeation in these tissues. Here we aimed to develop a new, advanced mechanistic mathematical model of the human epithelium that more accurately represents chemical tissue permeation. Using measurements of cell size and tortuosity from micrograph images of both human oral (buccal) and tissue-engineered buccal mucosa along with mechanistic mathematical modelling, we show that the convoluted geometry of the extracellular spaces within the epithelium significantly impacts chemical permeation. We next developed an advanced histologically and physiologically-relevant in silico model of buccal mucosal chemical permeation using partial differential equations, fitted to chemical permeation from in vitro assay data derived from tissue-engineered buccal mucosal models and chemicals with known physiochemical properties. Our novel in silico model can predict epithelial permeation kinetics for chemicals with different physicochemical properties in the absence or presence of permeability enhancers. This in vitro - in silico approach constitutes a step-change in the modelling of chemical tissue permeation and has the potential to expedite pharmaceutical innovation by improved and more rapid screening of chemical entities whilst reducing the need for in vivo animal experiments. Permeation ; In silico ; Extracellular ; Oral mucosa ; Chemistry ; Pharmaceutical technology ; Biophysics ; Biochemistry ; Chromatography ; Biology ; Anatomy ; Membrane Analytical Chemistry and Chromatography ; Lipid Membrane Structure and Behavior ; Hydrogels: synthesis, properties, applications
Authors: Neelima Chacko | Menachem Motiei | Suchita Suryakant Jadhav | Michael A. Firer | Rinat Ankri
Source: Discover Nano (article, 2024-01-25)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Au nanodyes as enhanced contrast agents in wide field near infrared fluorescence lifetime imaging The near-infrared (NIR) range of the electromagnetic (EM) spectrum offers a nearly transparent window for imaging tissue. Despite the significant potential of NIR fluorescence-based imaging, its establishment in basic research and clinical applications remains limited due to the scarcity of fluorescent molecules with absorption and emission properties in the NIR region, especially those suitable for biological applications. In this study, we present a novel approach by combining the widely used IRdye 800NHS fluorophore with gold nanospheres (GNSs) and gold nanorods (GNRs) to create Au nanodyes, with improved quantum yield (QY) and distinct lifetimes. These nanodyes exhibit varying photophysical properties due to the differences in the separation distance between the dye and the gold nanoparticles (GNP). Leveraging a rapid and highly sensitive wide-field fluorescence lifetime imaging (FLI) macroscopic set up, along with phasor based analysis, we introduce multiplexing capabilities for the Au nanodyes. Our approach showcases the ability to differentiate between NIR dyes with very similar, short lifetimes within a single image, using the combination of Au nanodyes and wide-field FLI. Furthermore, we demonstrate the uptake of Au nanodyes by mineral-oil induced plasmacytomas (MOPC315.bm) cells, indicating their potential for in vitro and in vivo applications. Fluorescence ; Fluorophore ; Materials science ; Fluorescence-lifetime imaging microscopy ; Near-infrared spectroscopy ; Nanorod ; Absorption (acoustics) ; Nanotechnology ; Optoelectronics ; Optics ; Physics Gold and Silver Nanoparticles Synthesis and Applications ; Nanocluster Synthesis and Applications ; Nanoparticle-Based Drug Delivery
Authors: Vincent Rigolot | Clémence Simon | Aude Bouchet | Lucas Lancel | Veronica Di Battista | Dmitry Karpov | Boris Vauzeilles | Corentin Spriet | Michel Sliwa | Sylvain Bohic | Christophe Biot | Cédric Lion
Source: RSC Chemical Biology (article, 2024-12-03)
Field: Chemistry — Organic Chemistry

Click-ready iridium( <scp>iii</scp> ) complexes as versatile bioimaging probes for bioorthogonal metabolic labeling Herein, we report the synthesis, photophysical characterization and validation of iridium(iii)-polypyridine complexes functionalized for click chemistry and bioorthogonal chemistry, as well as their versatile applications as probes in bioimaging studies exploiting metabolic labeling. The designed dyes are conjugated to chemical reporters in a specific manner within cells by CuAAC ligation and display attractive photophysical properties in the UV-visible range. They are indeed highly photostable and emit in the far-red to near-IR region with long lifetimes and large Stokes shifts. We demonstrate that they can be efficiently used to monitor nascent intracellular sialylated glycoconjugates in bioorthogonal MOE studies with a varied panel of optical and non-optical techniques, namely conventional UV-vis laser scanning confocal microscopy (for routine purposes), UV-vis time-resolved luminescence imaging (for specificity and facilitated multiplexing with nano-environment sensitivity), synchrotron radiation based X-ray fluorescence nanoimaging (for high resolution, elemental mapping and quantification <i>in situ</i>) and inductively coupled plasma mass spectrometry (for routine quantification on cell populations with high statistical confidence). The synthesized Ir(iii) complexes were utilized in single labeling experiments, as well as in dual click-labeling experiments utilizing two distinct monosaccharide reporters relevant to the same metabolic pathway. Bioorthogonal chemistry ; Click chemistry ; Chemistry ; Fluorescence ; Iridium ; Bioconjugation ; Combinatorial chemistry ; Nanotechnology ; Materials science ; Biochemistry ; Catalysis Click Chemistry and Applications ; Advanced Biosensing Techniques and Applications ; Monoclonal and Polyclonal Antibodies Research