jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Hemanta Chutia | Charu Lata Mahanta
Source: Grasas y Aceites (article, 2024-09-30)
Field: Chemistry — Organic Chemistry

Kinetic modelling of combined ultrasonication and Soxhlet based extraction of lipids from passion fruit seed using ethanol as solvent The aim of this study was to understand the extraction phenomena of oil from passion fruit seeds (PFS) using Soxhlet, ultrasonic-assisted extraction (UAE), and combined UAE-Soxhlet (UAES) methods and to investigate the physicochemical properties of the oil. The effect of solid-liquid ratio, temperature, and time of the UAE treatment on PFS oil (PFSO) yield was investigated and optimized. Phenomenological model parameters, viz. washing constant (0,807–1,139×10–1min–1) was faster than the diffusion constant parameter (5.0–5.4×10–3min–1) throughout the extraction process, and the washing constant was the highest for UAES. The composition of phenolics and fatty acids in the optimized oil extract was investigated by HPLC and GC, respectively. The comparison of the quality parameters of the extracted oils revealed that the combination of ultrasound and Soxhlet extraction is a viable alternative extraction procedure for obtaining better quality. The phenomenological model with combined extraction could be recommended for modelling extraction kinetics for better quality products and could be used for industrial purposes. Extraction (chemistry) ; Chromatography ; Sonication ; Yield (engineering) ; Solvent ; Chemistry ; Passion fruit ; Pulp and paper industry ; Materials science ; Food science ; Organic chemistry Edible Oils Quality and Analysis ; Antioxidant Activity and Oxidative Stress ; Free Radicals and Antioxidants
Authors: Nathan D. Rock | Haobo Yang | Brian A. Eisner | A.D. Levin | Arkka Bhattacharyya | Sriram Krishnamoorthy | Praneeth Ranga | Michael Walker | Larry Wang | Ming Kit Cheng | Wei Zhao | Michael A. Scarpulla
Source: arXiv (Cornell University) (preprint, 2024-03-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Utilizing (Al, Ga)2O3/Ga2O3 superlattices to measure cation vacancy diffusion and vacancy-concentration-dependent diffusion of Al, Sn, and Fe in \b{eta} -Ga2O3 Diffusion of native defects such as vacancies and their interactions with impurities are fundamental in semiconductor crystal growth, device processing, and long-term aging of equilibration and transient diffusion of vacancies are rarely investigated. We used aluminum-gallium oxide/gallium oxide superlattices (SLs) to detect and analyze transient diffusion of cation vacancies during annealing in O2 at 1000-1100 C. Using a novel finite difference scheme for the diffusion equation with time- and space-varying diffusion constant, we extract diffusion constants for Al, Fe, and cation vacancies under the given conditions, including the vacancy concentration dependence for Al. indicate that vacancies present in the substrate transiently diffuse through the SLs, interacting with Sn as it also diffuses. In the case of SLs grown on Sn-doped beta-gallium oxide substrates, gradients observed in the extent of Al diffusion indicate that vacancies present in the substrate transiently diffuse through the SLs, interacting with Sn as it also diffuses. In the case of SLs grown on (010) Fe-doped substrates, the Al diffusion is uniform through the SLs, indicating a depth-uniform concentration of vacancies. We find no evidence in either case for the introduction of gallium vacancies from the free surface at rates sufficient to affect Al diffusion down to ppm concentrations, which has important bearing on the validity of typically-made assumptions of vacancy equilibration. Additionally, we show that unintentional impurities in Sn-doped gallium oxide such as Fe, Ni, Mn, Cu, and Li also diffuse towards the surface and accumulate. Many of these likely have fast interstitial diffusion modes capable of destabilizing devices over time, thus highlighting the importance of controlling unintentional impurities in beta-gallium oxide wafers. Vacancy defect ; Diffusion ; Measure (data warehouse) ; Materials science ; Superlattice ; Crystallography ; Chemistry ; Thermodynamics ; Physics ; Optoelectronics ; Data mining Ga2O3 and related materials ; Advanced Photocatalysis Techniques ; Magnesium Oxide Properties and Applications
Authors: Vladimir Kulagin | Rémi Delaporte-Mathurin | E.A. Hodille | Mikhail Zibrov
Source: arXiv (Cornell University) (preprint, 2024-11-25)
Field: Materials Science — Materials Chemistry

Kinetic surface model in FESTIM: Verification and Validation The open-source code FESTIM (Finite Element Simulation of Tritium In Materials) is a powerful user-friendly software for hydrogen transport simulations. Up to now, it was capable of addressing various hydrogen transport problems with surface processes dependent on the concentration of solute species. However, the kinetics of surface hydrogen concentration should be considered under certain conditions. The recent 1.3 release of FESTIM introduced a new kinetic surface model, implemented in a flexible way for various applications. The correctness of the implementation is first proven using the method of manufactured solutions. Then, reliability of the model is demonstrated by reproducing four experimental cases on dynamics of hydrogen isotope retention in different materials. An additional cross-code comparison with two other simulation packages, MHIMS and TESSIM-X, shows an excellent agreement and strengthens the validity of the model. Model validation ; Computer science ; Data science Thermal properties of materials
Authors: Dipanjan Chaudhuri | Qianni Jiang | Xuefei Guo | Jin Chen | Caitlin S. Kengle | Farzaneh Hoveyda-Marashi | C. M. Bernal-Choban | N de Vries | T.‐C. Chiang | Eduardo Fradkin | I. R. Fisher | Peter Abbamonte
Source: arXiv (Cornell University) (preprint, 2024-11-22)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Measurement of the dynamic charge susceptibility near the charge density wave transition in ErTe$_3$ A charge density wave (CDW) is a phase of matter characterized by a periodic modulation of the valence electron density accompanied by a distortion of the lattice structure. The microscopic details of CDW formation are closely tied to the dynamic charge susceptibility, $χ(q,ω)$, which describes the behavior of electronic collective modes. Despite decades of extensive study, the behavior of $χ(q,ω)$ in the vicinity of a CDW transition has never been measured with high energy resolution ($\sim$meV). Here, we investigate the canonical CDW transition in ErTe$_3$ using momentum-resolved electron energy loss spectroscopy (M-EELS), a technique uniquely sensitive to valence band charge excitations. Unlike phonons in these materials, which undergo conventional softening due to the Kohn anomaly at the CDW wavevector, the electronic excitations display purely relaxational dynamics that are well described by a diffusive model. The diffusivity peaks around 250 K, just below the critical temperature. Additionally, we report, for the first time, a divergence in the real part of $χ(q,ω)$ in the static limit ($ω\rightarrow 0$), a phenomenon predicted to characterize CDWs since the 1970s. These results highlight the importance of energy- and momentum-resolved measurements of electronic susceptibility and demonstrate the power of M-EELS as a versatile probe of charge dynamics in materials. Charge (physics) ; Charge density wave ; Charge density ; Transition (genetics) ; Physics ; Condensed matter physics ; Chemistry ; Quantum mechanics Organic and Molecular Conductors Research ; Rare-earth and actinide compounds ; Iron-based superconductors research
Authors: Mohamed Abd El-Fadeel
Source: Journal of King Abdulaziz University-Science (article, 2024-11-12)
Field: Chemistry — Organic Chemistry

Simplified Approach for Environmental Remediation of Methylene Blue and Crystal Violet from Aqueous Solution Utilizing Nanoclay Material: Kinetic, Isotherm, Thermodynamic Studies This paper explains a rapid, simple, easy, and eco-friendly method for the elimination of the dyes Crystal Violet (C.V) and Methylene Blue (M.B) from aquatic solution onto eco-friendly Halloysite nanoclay (HSNC) solid phase. Physical features of the HSNC as SEM, TEM, XRD, FTIR, and BET were studied. The study examined various parameters that impact adsorption efficiency, including pH solution, adsorbent dosage, temperature, contact time, and KNO3 concentration. The efficiency of CV and MB dyes' adsorption on HSNC was studied kinetically and obtained data showed the processes were organized via a pseudo-second order (PSO) system through calculated adsorption capacity (qe,cal) were 46.72 mg/g for C.V and 43.47 mg/g for M.B dyes on HSNC. Under best conditions, the Langmuir model was found suitable model for explaining the isotherm behavior for removal CV and MB dyes onto HSNC, with maximum adsorption capacity (qm) 45.25 mg/g for C.V and 44.44 mg/g for M.B. Also, the thermodynamic study indicates the removal of C.V and M.B dyes is an endothermic process, and the adsorption of dyes is a chemisorption and spontaneous process. Finally, testing the elimination efficiency of CV and MB dyes based on three different actual samples on HSNC gave (E%) more than 93%. Overall, it was discovered that HSNC was an inexpensive, ecologically friendly substance for eliminating cationic CV and MB dyes. Crystal violet ; Methylene blue ; Aqueous solution ; Kinetic energy ; Environmental remediation ; Materials science ; Chemical engineering ; Chemistry ; Thermodynamics ; Physical chemistry ; Contamination ; Organic chemistry ; Physics ; Engineering Inorganic and Organometallic Chemistry ; Adsorption and biosorption for pollutant removal ; Water Quality Monitoring and Analysis
Authors: Qiang Du | Kai Wang | Jiang Yang
Source: arXiv (Cornell University) (preprint, 2024-07-21)
Field: Materials Science — Materials Chemistry

Computational and analytical studies of a new nonlocal phase-field crystal model in two dimensions A nonlocal phase-field crystal (NPFC) model is presented as a nonlocal counterpart of the local phase-field crystal (LPFC) model and a special case of the structural PFC (XPFC) derived from classical field theory for crystal growth and phase transition. The NPFC incorporates a finite range of spatial nonlocal interactions that can account for both repulsive and attractive effects. The specific form is data-driven and determined by a fitting to the materials structure factor, which can be much more accurate than the LPFC and previously proposed fractional variant. In particular, it is able to match the experimental data of the structure factor up to the second peak, an achievement not possible with other PFC variants studied in the literature. Both LPFC and fractional PFC (FPFC) are also shown to be distinct scaling limits of the NPFC, which reflects the generality. The advantage of NPFC in retaining material properties suggests that it may be more suitable for characterizing liquid-solid transition systems. Moreover, we study numerical discretizations using Fourier spectral methods, which are shown to be convergent and asymptotically compatible, making them robust numerical discretizations across different parameter ranges. Numerical experiments are given in the two-dimensional case to demonstrate the effectiveness of the NPFC in simulating crystal structures and grain boundaries. Field (mathematics) ; Phase (matter) ; Statistical physics ; Physics ; Theoretical physics ; Mathematics ; Quantum mechanics ; Pure mathematics Solidification and crystal growth phenomena ; Differential Equations and Numerical Methods ; Advanced Mathematical Modeling in Engineering
Authors: Zi-Jun Gao | Shu Ge | Jian Qian
Source: arXiv (Cornell University) (preprint, 2024-06-12)
Field: Chemistry — Inorganic Chemistry

Bridging multiple worlds: multi-marginal optimal transport for causal partial-identification problem Under the prevalent potential outcome model in causal inference, each unit is associated with multiple potential outcomes but at most one of which is observed, leading to many causal quantities being only partially identified. The inherent missing data issue echoes the multi-marginal optimal transport (MOT) problem, where marginal distributions are known, but how the marginals couple to form the joint distribution is unavailable. In this paper, we cast the causal partial identification problem in the framework of MOT with $K$ margins and $d$-dimensional outcomes and obtain the exact partial identified set. In order to estimate the partial identified set via MOT, statistically, we establish a convergence rate of the plug-in MOT estimator for the $\ell_2$ cost function stemming from the variance minimization problem and prove it is minimax optimal for arbitrary $K$ and $d \le 4$. We also extend the convergence result to general quadratic objective functions. Numerically, we demonstrate the efficacy of our method over synthetic datasets and several real-world datasets where our proposal consistently outperforms the baseline by a significant margin (over 70%). In addition, we provide efficient off-the-shelf implementations of MOT with general objective functions. Bridging (networking) ; Identification (biology) ; Computer science ; Mathematical optimization ; Mathematics ; Mathematical economics ; Biology Radioactive element chemistry and processing ; Markov Chains and Monte Carlo Methods
Authors: Yuta Sakamoto | Takahiro Sakaue
Source: arXiv (Cornell University) (preprint, 2024-05-20)
Field: Chemistry — Physical and Theoretical Chemistry

Method of Filtration in first passage time problems Statistics of stochastic processes are crucially influenced by the boundary conditions. In one spatial dimension, for example, the first passage time distribution in semi-infinite space (one absorbing boundary) is markedly different from that in a finite interval with two absorbing boundaries. Here, we propose a method, which we refer to as a method of filtration, that allows us to construct the latter from only the knowledge of the former. We demonstrate that our method yields two solution forms, a method of eigenfunction expansion-like form and a method of image-like form. In particular, we argue that the latter solution form is a generalization of the method of image applicable to a stochastic process for which the method of image generally does not work, e.g., the Ornstein-Uhlenbeck process. Filtration (mathematics) ; Computer science ; Mathematics ; Statistics Electrostatics and Colloid Interactions
Authors: Takumi Yamazaki | Takamasa Hirai | Takashi Yagi | Yuichiro Yamashita | Ken‐ichi Uchida | Takeshi Seki | Kōki Takanashi
Source: arXiv (Cornell University) (preprint, 2024-01-22)
Field: Materials Science — Materials Chemistry

Quantitative measurement of figure of merit for transverse thermoelectric conversion in Fe/Pt metallic multilayers This study presents a measurement method for determining the figure of merit for transverse thermoelectric conversion ($ z_\mathrm{T}T $) in thin film forms. Leveraging the proposed methodology, we comprehensively investigate the transverse thermoelectric coefficient ($ S_\mathrm{T} $), in-plane electrical conductivity ($ σ_{yy} $), and out-of-plane thermal conductivity ($ κ_{xx} $) in epitaxial and polycrystalline Fe/Pt metallic multilayers. The $ κ_{xx} $ values of multilayers with a number of stacking repetitions ($ N $) of 200 are lower than those of FePt alloy films, indicating that the multilayer structure effectively contributes to the suppression of $ κ_{xx} $. $ z_\mathrm{T}T $ is found to increase with increasing $ N $, which remarkably reflects the $ N $-dependent enhancement of the $ S_\mathrm{T} $ values. Notably, $ S_\mathrm{T} $ and $ σ_{yy} $ are significantly larger in the epitaxial multilayers than those in the polycrystalline counterparts, whereas negligible differences in $ κ_{xx} $ are observed between the epitaxial and polycrystalline multilayers. This discrepancy in $ σ_{yy} $ and $ κ_{xx} $ with respect to crystal growth is due to the different degree of anisotropy in electron transport between epitaxial and polycrystalline multilayers, and epitaxial growth can lead to an enhancement of $ z_\mathrm{T}T $ in the multilayers. This study is the first demonstration in the evaluation of $ z_\mathrm{T}T $ in thin film forms, and our proposed measurement technique reveals the transverse thermoelectric properties inherent to multilayers. Epitaxy ; Condensed matter physics ; Seebeck coefficient ; Crystallite ; Thermoelectric effect ; Materials science ; Figure of merit ; Anisotropy ; Thermal conductivity ; Physics ; Nanotechnology ; Optics ; Optoelectronics ; Thermodynamics ; Composite material ; Metallurgy Advanced Thermoelectric Materials and Devices ; Surface and Thin Film Phenomena ; Heusler alloys: electronic and magnetic properties
Authors: Zekun Hu | Sudong Wang | Jason Lynch | Deep Jariwala
Source: arXiv (Cornell University) (preprint, 2024-06-15)
Field: Materials Science — Materials Chemistry

Tandem Photovoltaics from 2D Transition Metal Dichalcogenides on Silicon The demand for high-efficiency photovoltaic systems necessitates innovations that transcend the efficiency limitations of single-junction solar cells. This study investigates a tandem photovoltaic architecture comprising a top-cell with a transition metal dichalcogenide (TMDC) superlattice absorber and a bottom-cell of crystalline silicon (c-Si), focusing on optimizing the light absorption and electrical performance of the combined structure. Through the transfer matrix method and electrical simulations, we optimized the geometry of the superlattice, determining that a siz-layer MoSe2 configuration with a 40 nm SiO2 antireflective layer maximizes photon absorption while mitigating additional weight and preserving the cell's structural integrity. The results show that the optimized TMDC superlattice significantly improves the PCE of the tandem design to 28.96%, and increase of 5.68% over the original single-junction c-Si solar cell's efficiency. This advancement illustrates the potential of TMDC material in next-generation solar cells and presents a promising avenue for the development of highly efficient, tandem photovoltaic systems via van der Waals integration of the top cell on c-Si Photovoltaics ; Tandem ; Silicon ; Transition metal ; Materials science ; Nanotechnology ; Engineering physics ; Optoelectronics ; Photovoltaic system ; Chemistry ; Engineering ; Electrical engineering 2D Materials and Applications ; Chalcogenide Semiconductor Thin Films ; Semiconductor materials and interfaces
Authors: Zeinab Khosravizadeh | Anastasiia Lysak | E. Przeździecka | R. Jakieła
Source: Materials (article, 2024-10-28)
Field: Materials Science — Materials Chemistry

SIMS and Numerical Analysis of Asymmetrical Out-Diffusion of Hydrogen and Carbon in CdxZn1−xO:Eu Multilayer This study employs secondary ion mass spectrometry (SIMS) to investigate the diffusion behavior of hydrogen and carbon in a Cd<i><sub>x</sub></i>Zn<sub>1-<i>x</i></sub>O:Eu multilayer at different annealing temperatures (500-900 °C). The SIMS results reveal a significant out-diffusion of these elements toward the surface and diffusion to the interface region. The diffusion flow rates are asymmetric and favor the interface direction. The depth profiles of diffused elements are fitted using the forward timecentered space (FTCS) iteration method. The activation energies are determined to be 0.35 ± 0.06 eV for hydrogen and 0.33 ± 0.09 eV for carbon, suggesting an interstitial mechanism in Cd<sub><i>x</i></sub>Zn<sub>1-<i>x</i></sub>O. The results indicate that increasing the annealing temperatures leads to a significant decrease in impurity concentrations. Secondary ion mass spectrometry ; Hydrogen ; Annealing (glass) ; Diffusion ; Analytical Chemistry (journal) ; Impurity ; Secondary Ion Mass Spectroscopy ; Ion ; Materials science ; Hydrogen ion ; Carbon fibers ; Chemistry ; Thermodynamics ; Silicon ; Metallurgy ; Composite material ; Chromatography ZnO doping and properties ; Advanced Condensed Matter Physics ; Nuclear Materials and Properties
Authors: Michael Macias | Alejandro Altamirano Briones | Erika Góngora-Muñoz | Alex Ariel Fernández-Andrade | Kevin Jhon Fernández-Andrade
Source: Revista Colombiana de Química (article, 2024-04-10)
Field: Chemistry — Analytical Chemistry

Adsorption of Brilliant blue FCF (B1) and Allura Red (R40) colorants on cocoa shell: kinetics of the process The use of dyes in food industrial processes is limited due to significant pollution in aquatic receptors from their wastewater. To address this issue, this study focused on evaluating the adsorption of dyes Allura Red (R40) and Brilliant blue FCF (B1) using cocoa shells (CS) as an absorbent. To achieve this, a pre-treatment was applied, which involved washing, grinding and drying at a temperature of 80 °C for 24 h, followed by a sieving process. The effect of the adsorbent dose was then analyzed and it was calculated that the optimal dose was 4 g/L. Additionally, the effect of contact time was studied through a kinetic analysis, all tests were carried out at a pH level of 2. The obtained data were fitted to kinetic models, which allowed us to conclude that the adsorption kinetics fit two different models depending on the initial solution conditions, in a range from 0 to 0.1512 mmol/L. Specifically, the Pseudo Second-Order (PSO) model fitted R40, while the Elovich model was appropriate for B1. In summary, CS was found to be a viable adsorbent for dyes in contaminated waters. Adsorption ; Kinetics ; Chemistry ; Chromatography ; Organic chemistry ; Physics Dye analysis and toxicity
Authors: Huifang Zhou | Yuchun Sun null | Fuchang Huo
Source: International Journal of Numerical Analysis and Modeling (article, 2024-10-09)
Field: Chemistry — Spectroscopy

A Finite Volume Method Preserving the Invariant Region Property for the Quasimonotone Reaction-Diffusion Systems We present a finite volume method preserving the invariant region property (IRP) for the reaction-diffusion systems with quasimonotone functions, including nondecreasing, decreasing, and mixed quasimonotone systems. The diffusion terms and time derivatives are discretized using a finite volume method that satisfies the discrete maximum principle (DMP) and the backward Euler method, respectively. The discretization leads to an implicit and nonlinear scheme, and it is proved to preserve the invariant region property unconditionally. We construct an iterative algorithm and prove the invariant region property at each iteration step. Numerical examples are provided to confirm the accuracy and invariant region property of our scheme. Mathematics ; Reaction–diffusion system ; Invariant (physics) ; Property (philosophy) ; Finite volume method ; Volume (thermodynamics) ; Mathematical analysis ; Applied mathematics ; Pure mathematics ; Mechanics ; Mathematical physics ; Thermodynamics ; Physics ; Philosophy Analytical Chemistry and Chromatography
Authors: M. E. Caplan | D. Yaacoub
Source: arXiv (Cornell University) (preprint, 2024-09-11)
Field: Materials Science — Materials Chemistry

Universal Diffusion in Coulomb Crystals Diffusion coefficients for crystallized Coulomb plasmas are essential microphysics input for modeling white dwarf cores and neutron star crusts but are poorly understood. In this work we present a model for diffusion in Coulomb crystals. We show that melting and diffusion follow the same universal scaling such that diffusion is independent of screening. Our simulations show, contrary to prevailing wisdom, that the formation of vacancies is not suppressed by the large pressure. Rather, vacancy formation and hole diffusion is the dominant mode of self diffusion in Coulomb crystals. Coulomb ; Diffusion ; Condensed matter physics ; Physics ; Statistical physics ; Theoretical physics ; Materials science ; Chemical physics ; Quantum mechanics ; Electron X-ray Diffraction in Crystallography