jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: D. Kechrakos | Vito Puliafito | A. Riveros | Jiahao Liu | Wanjun Jiang | Mario Carpentieri | Riccardo Tomasello | Giovanni Finocchio
Source: arXiv (Cornell University) (preprint, 2023-09-11)
Field: Materials Science — Materials Chemistry

Skyrmions in nanorings: a versatile platform for Skyrmionics The dynamical properties of skyrmions can be exploited to build devices with new functionalities. Here, we first investigate a skyrmion-based ring-shaped device by means of micromagnetic simulations and Thiele equation. We subsequently show three applications scenarios: (1) a clock with tunable frequency that is biased with an electrical current having a radial spatial distribution, (2) an alternator, where the skyrmion circular motion driven by an engineered anisotropy gradient is converted into an electrical signal, and (3) an energy harvester, where the skyrmion motion driven by a thermal gradient is converted into an electrical signal, thus providing a heat recovery operation. We also show how to precisely tune the frequency and amplitude of the output electrical signals by varying material parameters, geometrical parameters, number and velocity of skyrmions, and we further prove the correct device functionality under realistic conditions given by room temperature and internal material defects. Our results open a new route for the realization of energy efficient nanoscale clocks, generators, and energy harvesters. Skyrmion ; SIGNAL (programming language) ; Anisotropy ; Amplitude ; Realization (probability) ; Energy (signal processing) ; Temperature gradient ; Thermal ; Alternator ; Physics ; Computer science ; Condensed matter physics ; Optics ; Mathematics ; Quantum mechanics Advanced Thermoelectric Materials and Devices ; Magnetic properties of thin films ; Advanced Materials and Mechanics
Authors: Xiaozhen Yang | Erda Wen | Dinesh Bharadia | Daniel F. Sievenpiper
Source: arXiv (Cornell University) (preprint, 2023-07-27)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Multifunctional Metasurface: Simultaneous Beam Steering, Polarization Conversion and Phase Offset A varactor-based reconfigurable multifunctional metasurface capable of simultaneous beam steering, polarization conversion and phase offset is proposed in this paper. The unit cell is designed to naturally decompose the incident waves into two equal amplitude orthogonal linear components, and by integrating varactors, the reflection phase of the field components can be engineered from $-180^{\circ}$ to $180^{\circ}$.Taking advantage of the infinite states of the varactors, this design integrates a new function, the phase offset. After simulation validation of its capability, a four-layer $7$ by $6$ unit one-dimensional prototype is fabricated as a printed circuit board. It is experimentally demonstrated that it switches between X/Y and circular polarization with more than $10$ dB cross polarization isolation, while reaching $\pm45^{\circ}$ steering and $\pm180^{\circ}$ phase offset. Varicap ; Offset (computer science) ; Beam steering ; Polarization (electrochemistry) ; Optics ; Amplitude ; Phase difference ; Materials science ; Physics ; Optoelectronics ; Phase (matter) ; Beam (structure) ; Computer science ; Electrode ; Capacitance Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Antenna Design and Analysis
Authors: Mujan N. Seif | Jake Puppo | Metodi Zlatinov | Denver Schaffarzick | Alexandre Martin | Matthew J. Beck
Source: arXiv (Cornell University) (preprint, 2023-02-28)
Field: Materials Science — Materials Chemistry

Stochastic mechanical modeling of metallic foams to determine onset of mesoscale behavior Metallic foams are crucial to many emerging applications, among them shielding against hypervelocity impacts caused by micrometeoroids and orbital debris. The variability of properties at feature-scale and mesoscale lengths originating from the foam's inherently random microstructure makes predictive models of their properties challenging. It also hinders the optimization of components fabricated with such foams, an especially serious problem for spacecraft design where the balance between cost and mass must also be balanced against the catastrophic results of component failure. To address this problem, we compute the critical transition length between the feature-scale, where mechanical properties are determined by individual features, and the mesoscale, where behavior is determined by ensembles of features. At the mesoscale, distributions of properties -- with respect to both expectation value and standard variability -- are consistent and predictable. The Kentucky Random Structure Toolkit (KRaSTk) is applied to determine the transition from feature-scale to mesoscale for computational volumes representing metallic foams at a range of reduced densities. The transition is found to occur when the side length of a cubic sample volume is ~10x greater than the characteristic length. Comparing KRaSTk-computed converged stiffness distributions with experimental measurements of a commercial metallic foam found excellent agreement for both expectation value and standard variability at all reduced densities. Lastly, we observe that the diameter of a representative MMOD strike is ~30x shorter than the feature-scale to mesoscale transition for the foam at any reduced density. Therefore, features will determine response to hypervelocity impacts, rather than bulk (or even mesoscale) structure. Mesoscale meteorology ; Materials science ; Stiffness ; Range (aeronautics) ; Hypervelocity ; Feature (linguistics) ; Mechanics ; Physics ; Composite material ; Meteorology ; Thermodynamics High-Velocity Impact and Material Behavior ; Cellular and Composite Structures ; Probabilistic and Robust Engineering Design
Authors: Mohammad Amin Rashidi | Mohammad Reza Khademahmadi | Yousef Kazemzadeh | Masoud Riazi
Source: Scientific Reports (article, 2023-03-08)
Field: Chemistry — Analytical Chemistry

Modeling and comparing minimum miscibility pressure using multiple mixing cells for injection of enriched gases with Naphta, LPG, and NGL The increase in oil production from hydrocarbon reservoirs has always been of interest due to the increase in global oil consumption. One of the effective and useful methods for enhancing oil recovery from hydrocarbon reservoirs is gas injection. Injectable gas can be injected into two modes, miscible and immiscible. However, to inject more efficiently, different factors, including Minimum Miscibility Pressure (MMP) in the gas near-miscible injection mode, should be investigated and determined. In order to investigate the minimum miscible pressure, different laboratory and simulation methods have been prepared and developed. This method uses the theory of multiple mixing cells to simulate, calculate and compare the minimum miscible pressure in gas injection enriched with Naptha, LPG, and NGL. Also vaporizing and condensing process is also considered in the simulation. The constructed model is presented with a new algorithm. This modeling has been validated and compared with laboratory results. The results showed that dry gas enriched by Naphta due to having more intermediate compounds at lower pressure (16 MPa) is miscible. In addition, dry gas, due to very light compounds, needs higher pressures (20 MPa) than all enriched gases for miscibility. Therefore, Naptha can be a good option for injecting rich gas into oil reservoirs to enrich gas. Miscibility ; Mixing (physics) ; Petroleum engineering ; Dry gas ; Hydrocarbon ; Materials science ; Enhanced oil recovery ; Chemical engineering ; Thermodynamics ; Chemistry ; Environmental science ; Chromatography ; Geology ; Organic chemistry ; Polymer ; Engineering Petroleum Processing and Analysis ; Enhanced Oil Recovery Techniques ; Reservoir Engineering and Simulation Methods
Authors: G. Canocchi | L. Malavolta | I. Pagano | Oscar Barragán | G. Piotto | S. Aigrain | S. Desidera | S. Grziwa | J. Cabrera | H. Rauer
Source: arXiv (Cornell University) (preprint, 2023-02-04)
Field: Chemistry — Spectroscopy

Discovering planets with PLATO: Comparison of algorithms for stellar activity filtering Context. To date, stellar activity is one of the main limitations in detecting small exoplanets via transit photometry. Since this activity is enhanced in young stars, traditional filtering algorithms may severely under-perform in detecting such exoplanets. Aims.This paper aims to compare the relative performances of four algorithms developed by independent research groups specifically for the filtering of activity in the light curves (LCs) of young active stars, prior to the search for planetary transit signals: Notch and LOCoR(N&amp;L), Young Stars Detrending(YSD), K2 Systematics Correction(K2SC) and VARLET. We include in the comparison also the two best-performing algorithms implemented in Wotan, namely the Tukey's biweight and the Huber Spline. Methods. We performed a series of injection-retrieval tests of planetary transits of different types, from Jupiter down to Earth-sized planets, moving both on circular and eccentric orbits. The tests were carried out over 100 simulated LCs of both quiet and active solar-like stars that will be observed by the ESA space telescope PLATO. Results. We found that N&amp;L is the best choice in many cases, since it misses the lowest number of transits. However, it under-performs if the planetary orbital period closely matches the stellar rotation period, especially in the case of small planets for which the biweight and VARLET algorithms work better. For LCs with a large number of data, the combined results of YSD and Huber Spline yield the highest recovery percentage. Filtering algorithms allow us to get a very precise estimate of the orbital period and the mid-transit time of the detected planets, while the planet-to-star radius is under-estimated most of the time, especially in the case of grazing transits or eccentric orbits. A refined filtering taking into account the presence of the planet is compulsory for a proper planetary characterization. Planet ; Astrobiology ; Computer science ; Algorithm ; Astronomy ; Physics Molecular spectroscopy and chirality
Authors: Chaitanya Goswami | Amanda Merkley | Pulkit Grover
Source: arXiv (Cornell University) (preprint, 2023-05-11)
Field: Materials Science — Materials Chemistry

Computing Unique Information for Poisson and Multinomial Systems Bivariate Partial Information Decomposition (PID) describes how the mutual information between a random variable M and two random variables Y and Z is decomposed into unique, redundant, and synergistic terms. Recently, PID has shown promise as an emerging tool to understand biological systems and biases in machine learning. However, computing PID is a challenging problem as it typically involves optimizing over distributions. In this work, we study the problem of computing PID in two systems: the Poisson system inspired by the 'ideal Poisson channel' and the multinomial system inspired by multinomial thinning, for a scalar M. We provide sufficient conditions for both systems under which closed-form expressions for many operationally-motivated PID can be obtained, thereby allowing us to easily compute PID for these systems. Our proof consists of showing that one of the unique information terms is zero, which allows the remaining unique, redundant, and synergistic terms to be easily computed using only the marginal and the joint mutual information. Multinomial distribution ; PID controller ; Poisson distribution ; Computer science ; Bivariate analysis ; Mutual information ; Scalar (mathematics) ; Random variable ; Mathematics ; Artificial intelligence ; Statistics ; Machine learning Machine Learning in Materials Science ; Random Matrices and Applications
Authors: Daniel Dörfler | Andreas Löhne
Source: arXiv (Cornell University) (preprint, 2023-05-26)
Field: Chemistry — Organic Chemistry

Polyhedral approximation of spectrahedral shadows via homogenization This article is concerned with the problem of approximating a not necessarily bounded spectrahedral shadow, a certain convex set, by polyhedra. By identifying the set with its homogenization the problem is reduced to the approximation of a closed convex cone. We introduce the notion of homogeneous δ-approximation of a convex set and show that it defines a meaningful concept in the sense that approximations converge to the original set if the approximation error δ diminishes. Moreover, we show that a homogeneous δ-approximation of the polar of a convex set is immediately available from an approximation of the set itself under mild conditions. Finally, we present an algorithm for the computation of homogeneous δ-approximations of spectrahedral shadows and demonstrate it on examples. Polyhedron ; Homogenization (climate) ; Mathematics ; Bounded function ; Regular polygon ; Homogeneous ; Computation ; Convex set ; Convex polytope ; Approximation algorithm ; Approximations of π ; Combinatorics ; Mathematical optimization ; Applied mathematics ; Convex optimization ; Mathematical analysis ; Algorithm ; Geometry Surfactants and Colloidal Systems ; Electrostatics and Colloid Interactions ; Water Systems and Optimization
Authors: Chengyuan Cai | Dante M. Kennes | Michael A. Sentef | Tao Yu
Source: RWTH Publications (RWTH Aachen) (preprint, 2023-07-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Edge and corner skin effects of chirally coupled magnons characterized by a topological winding tuple We investigate a long-ranged coupled and non-Hermitian two-dimensional array of nanomagnets, fabricated on a thin magnetic substrate and subjected to an in-plane magnetic field. We predict topology-driven edge and corner skin effects of magnetic eigenmodes with the localization position at boundaries precisely characterized by a topological winding tuple $({\cal W}_1,{\cal W}_2)$. By varying the direction of the in-plane field, all magnon states pile up either at different edges of the array with $({\cal W}_1=\pm 1,{\cal W}_2=0)$ or $({\cal W}_1=0,{\cal W}_2=\pm 1)$, or at different corners characterized by $({\cal W}_1=\pm 1,{\cal W}_2=\pm 1)$. Exploiting the non-Hermitian topology is potentially helpful for designing useful magnonic metasurface in the future. Topology (electrical circuits) ; Physics ; Magnetic field ; Magnon ; Plane (geometry) ; Enhanced Data Rates for GSM Evolution ; Hermitian matrix ; Condensed matter physics ; Geometry ; Quantum mechanics ; Mathematics ; Combinatorics ; Ferromagnetism ; Computer science Metamaterials and Metasurfaces Applications ; Quantum Mechanics and Non-Hermitian Physics ; Topological Materials and Phenomena
Authors: Micaela Toscani | Axel M. Lacapmesure
Source:  (article, 2023-01-01)
Field: Materials Science — Surfaces, Coatings and Films

Improving the resolution of STED microscopy using the SUPPOSe algorithm Here we apply the gSUPPOSe algorithm on images acquired using Stimulated Emission Depletion (STED) microscopy with the aim of improving the resolution limit achieved. We processed images of the nuclear pore complex (NPC) from cell lines in which the Nup96 nucleoporin was endogenously labeled. This reference protein forms a ring whose diameter is ~107 nm with 8 corners ~42 nm apart from each other. The stereotypic arrangement of proteins in the NPC has been used as reference structures to characterize the performance of a variety of microscopy techniques. STED microscopy images resolve the ring arrangement but not the eightfold symmetry of the NPC. After applying the gSUPPOSe algorithm to the STED images, we were able to solve the octagonal structure of the NPC. After processing 500 Regions Of Interest (ROIs), the average radius of the NPC was found to be R = 54.2 ± 2.9 nm, being consistent with the theoretical distances of this structure. To verify that the solutions obtained are compatible with a NPC-type geometry, we rotate the solutions to optimally fit an eightfold-symmetric pattern and we count the number of corners that contain at least one localization. Fitting a probabilistic model to the histogram of the number of bright corners gives an effective labeling efficiency (ELE) of 31%, which is in agreement with the values reported in for other cell lines and ligands used in STORM images, showing that SUPPOSe can reliably retrieve sub-resolution, nanoscale objects even in such noisy conditions. STED microscopy ; Resolution (logic) ; Microscopy ; Algorithm ; Super-resolution microscopy ; Computer science ; Materials science ; Optics ; Physics ; Superresolution ; Artificial intelligence ; Scanning confocal electron microscopy ; Image (mathematics) Electron and X-Ray Spectroscopy Techniques
Authors: Samuel Talkington | Santiago Grijalva
Source: arXiv (Cornell University) (preprint, 2023-05-16)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Phase Retrieval via Model-Free Power Flow Jacobian Recovery Phase retrieval is a prevalent problem in digital signal processing and experimental physics that consists of estimating a complex signal from magnitude measurements. This paper expands the classical phase retrieval framework to electric power systems with unknown network models and limited access to observations of voltage magnitudes, active power injections, and reactive power injections. The proposed method recovers the phase angles and the power-phase angle submatrices of the AC power flow Jacobian matrix. This is made possible by deriving topology and parameter-free expressions for the structural symmetries of the power flow Jacobian that do not depend on the phase angles. These physical laws provide structural constraints for the proposed phase retrieval method. The paper then presents sufficient conditions for guaranteed recovery of the voltage phase angles, which also depend solely on voltage magnitudes, active power injections, and reactive power injections. The method offers two significant benefits: both estimating the voltage phase angles and recovering the power flow Jacobian matrix, a basis for approximating the power flow equations. Simulations on widely studied open-source test networks validate the findings. Jacobian matrix and determinant ; AC power ; Power (physics) ; Voltage ; Control theory (sociology) ; Flow (mathematics) ; Phase (matter) ; Three-phase ; Computer science ; Mathematics ; Topology (electrical circuits) ; Applied mathematics ; Physics ; Geometry ; Engineering ; Electrical engineering ; Artificial intelligence Magnetic Properties and Applications ; Advanced Electron Microscopy Techniques and Applications ; Model Reduction and Neural Networks
Authors: Sara L. Ellison | Hsi-An Pan | Asa F. L. Bluck | Mark R. Krumholz | Lihwai Lin | L. K. Hunt | E. Corbelli | Mallory Thorp | J. K. Barrera-Ballesteros | S. F. Sánchez | Jillian M. Scudder | S Quai
Source: arXiv (Cornell University) (preprint, 2023-12-05)
Field: Chemistry — Spectroscopy

The ALMaQUEST Survey XI: A strong but non-linear relationship between star formation and dynamical equilibrium pressure We present the extended ALMA MaNGA QUEnching and STar formation survey, a combination of the original 46 ALMaQUEST galaxies plus new ALMA observations for a further 20 interacting galaxies. Three well-studied scaling relations are fit to the 19,999 star-forming spaxels in the extended sample, namely the resolved Schmidt-Kennicutt (rSK) relation, the resolved star forming main sequence (rSFMS) and the resolved molecular gas main sequence (rMGMS). We additionally investigate the relationship between the dynamical equilibrium pressure (PDE) and star formation rate surface density (Sigma_SFR), which we refer to as the resolved PDE (rPDE) relation. Contrary to previous studies that have focussed on normal star-forming galaxies and found an approximately linear rPDE relation, the presence of more vigourously star-forming galaxies in the extended ALMaQUEST sample reveals a marked turnover in the relation at high pressures. Although the scatter around the linear fit to the rPDE relation is similar to the other three relations, a random forest analysis, which can extract non-linear dependences, finds that PDE is unambiguously more important than either Sigma_H2 or Sigma_star for predicting Sigma_SFR. We compare the observed rPDE relation to the prediction of the pressure-regulated feedback-modulated (PRFM) model of star formation, finding that galaxies residing on the global SFMS do indeed closely follow the rPDE relation predicted by the PRFM theory. However, galaxies above and below the global SFMS show significant deviations from the model. Galaxies with high SFR are instead consistent with models that include other contributions to turbulence in addition to the local star formation feedback. Physics ; Astrophysics ; Star formation ; Sigma ; Galaxy ; Star (game theory) ; Bar (unit) ; Relation (database) ; Astronomy Spectroscopy and Laser Applications ; Astrophysics and Star Formation Studies ; Phase Equilibria and Thermodynamics
Authors: Sónia Marília Castro | LA Azevedo | Sarah Eller | AR Spillere | TF Oliveira | B. de J. R. dos Santos | J. M. Almeida
Source:  (article, 2023-01-01)
Field: Chemistry — Analytical Chemistry

DESENVOLVIMENTO DE MÉTODO ANALÍTICO PARA DETERMINAÇÃO DE ANTIEPILÉPTICOS EM AMOSTRAS DE SORO POR LC-MS/MS Objetivo: A terapia farmacológica com antiepilépticos (AE) apresenta faixa terapêutica estreita, de forma que é necessária a dosagem de AE em soro, a fim de proceder com a monitorização terapêutica e promover melhor resultado clínico. Atualmente, os principais métodos de análise de AE se baseiam em testes imunoquímicos, cujos resultados apresentam seletividade e especificidade limitados. Este estudo tem como objetivo desenvolver e validar método de determinação de quatro antiepilépticos usados tradicionalmente na clínica e presentes na RENAME (ácido valproico, carbamazepina, fenitoína e fenobarbital) por cromatografia líquida acoplada à espectrometria de massas em tandem (LC-MS/MS) em amostras de soro. Método: O método foi desenvolvido e otimizado e, em seguida, foi realizada a validação conforme o ICH Guideline M10 on bioanalytical method validation (EMA, 2023) utilizando equipamento Nexera-i LC-2040C Plus acoplado ao espectrômetro de massas em modo tandem LC-MS8045 (Shimadzu, Japão). Os padrões analíticos e demais consumíveis foram provenientes das empresas Ceriliant Corporation®, Sigma-Aldrich®, Millipore Corporation® e Merck®. A coluna cromatográfica (Raptor bifenil; 50 × 3 mm, 2,7 μm) foi proveniente da Restek®. Conclusão: O tipo de solvente utilizado para a precipitação proteica foi otimizado utilizando um planejamento multivariado do tipo simplex-centroide, no qual a melhor resposta foi obtida utilizando uma mistura de metanol:isopropanol (3:1; v/v). O método desenvolvido apresentou linearidade para ácido valproico, carbamazepina e fenobarbital nas concentrações de 25-450 μg/ml, 1-40 μg/ml e 5-80 μg/ml, respectivamente. Os ensaios de precisão se mostraram coerentes para os analitos, apresentando coeficiente de variação menor que 15%. Após a completa validação, o método poderá ser aplicado com sucesso às análises de monitorização terapêutica em laboratórios clínicos. Physics ; Chemistry Analytical Methods in Pharmaceuticals ; Antibiotics Pharmacokinetics and Efficacy ; Pesticide Residue Analysis and Safety