jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Jiří Šmejcký | V. Jeřábek
Source: Journal of Material Science and Technology Research (article, 2020-03-27)
Field: Materials Science — Ceramics and Composites

Differential Gain Comparison of Optical Planar Amplifier on Silica Glasses Doped with Bi-Ge and Er, Yb Ions The paper presents the measurement and calculation of the optical amplifier gain and the optimal length of the active optical amplifier waveguide doped with Bi-Ge radiation complexes compared to an optical amplifier with active doping with ions Er3+, Yb3+. At present are using optical amplifiers for the high-capacity optical communication systems in the narrow spectral region of 1530–1560 nm, determined by the gain bandwidth of erbium-doped fiber amplifiers (EDFA) or erbium-doped optical planar amplifiers (EDPA) realized as active planar waveguides in the optical integrated circuits technique. However, it is possible increase wavelength region up to 1610 nm, where optical losses of telecommunication fibers are less than 0.3 dB per km, if appropriate amplifiers are available. In this regard, the development of novel optical amplifiers operating in this spectral region have of great importance. The paper summarizes the results measurement of the attenuation and emission spectra for net gain spectra calculation of the new ion exchange Ag+ – Na+ optical Er3+ and Yb3+ doped active planar waveguides realized on silica glass substrates and parameters of novel optical amplifiers for extension of the bandwidth from 1530 to 1610 nm doped by bismuth – erbium ions. Doping ; Materials science ; Planar ; Ion ; Optoelectronics ; Optical amplifier ; Optics ; Chemistry ; Physics ; Laser ; Computer science Glass properties and applications ; Photorefractive and Nonlinear Optics ; Quantum optics and atomic interactions
Authors: Marina García‐Pardo | Eva Nieto Pinero | A. K. Petford‐Long | R. Serna | Johann Toudert
Source: Nanophotonics (preprint, 2020-02-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Active analog tuning of the phase of light in the visible regime by bismuth‐based metamaterials Abstract The active and analog tuning of the phase of light by metamaterials is needed to boost the switching performance of photonic devices. However, demonstrations of this type of tuning in the pivotal visible spectral region are still scarce. Herein, we report the active analog tuning of the phase of visible light reflected by a bismuth (Bi)‐based metamaterial, enabled by a reversible solid‐liquid transition. This metamaterial, fabricated by following a lithography‐free approach, consists of two‐dimensional assemblies of polydisperse plasmonic Bi nanostructures embedded in a refractory and transparent aluminum oxide matrix. The analog tuning of the phase is achieved by the controlled heating of the metamaterial to melt a fraction of the nanostructures. A maximum tuning of 320° (1.8 π) is observed upon the complete melting of the nanostructures at 230°C. This tuning is reversible by cooling to 25°C. In addition, it presents a wide hysteretic character due to liquid Bi undercooling. This enables the phase achieved by this analog approach to remain stable over a broad temperature range upon cooling and until re‐solidification occurs around 100°C. Therefore, Bi‐based metamaterials are endowed with analog optical memory capabilities, which are appealing for a wide range of applications, including optical data storage with enhanced information density or bistable photonic switching with a tunable “on” state. Materials science ; Optoelectronics ; Metamaterial ; Photonics ; Bismuth ; Phase (matter) ; Optics Metamaterials and Metasurfaces Applications ; Photonic Crystals and Applications ; Plasmonic and Surface Plasmon Research
Authors: Giuseppe Meneghini
Source: The International Islamic University Malaysia Repository (The International Islamic University Malaysia) (article, 2020-11-01)
Field: Materials Science — Materials Chemistry

Electronic properties of twisted bilayer graphene In this thesis we will focus on the study of a two-layer graphene system, where a small relative rotation is applied. This system is called twisted bilayer graphene, tBLG. &#13;\nIn the last ten years many experimental works have shown that by twisting two layers of graphene by small angles, one can enhance the conducting properties of the system. Moreover at some specific angles, called “magic angles”, the lowest energy band turns to be very close to the Fermi level and becomes extremely flat. &#13;\nThis is of particular interest in the presence of ordered phases of matter like superconductivity. The densities of charge carriers is orders of magnitude lower than the typical two-dimensional superconductors and the measured critical temperature is however relatively high. This makes tBLG a strong coupling superconductor. The great advantage in tBLG with respect to other systems is the simple and fine tunability of carrier densities, magnetic field and temperature, that enables a complete and fine investigation of the rich phase diagram of such a strongly correlated system. Also the interlayer interactions can be fine-tuned by the modulation of the twist angle and/or the application of perpendicular electric fields and of uniaxial strain induced by non hydrostatic pressure. &#13;\nIn this work we study the tight binding model for the tBLG, which, in the continuum limit, correctly predicts the presence of angles at which the Fermi velocity vanishes, and, therefore, the presence of flat bands near these magic angles. In particular, we show how, in the low energy limit, one gets an analytical expression for the first magic angle, rederiving the effective model and providing all the details useful for the calculation skipped in literature. &#13;\nMoreover we perform the numerical calculation in order to obtain the full spectrum and the bandwidth for the lowest energy band. &#13;\nThe latter result is useful for us when considering the interacting system. In the presence of electron-electron attractive interaction mediated by the phonons, the system seems to sustain a superconducting phase. By means of a path integral approach we finally derive the corresponding critical temperature. Bilayer graphene ; Condensed matter physics ; Superconductivity ; Fermi energy ; Physics ; Graphene ; Magnetic field ; Fermi level ; Materials science ; Quantum mechanics ; Electron Graphene research and applications ; Advanced Physical and Chemical Molecular Interactions
Authors: Yolaine Danard | Lola Lilensten | Fan Sun | P. Vermaut | I. Freiherr von Thüngen | Guilhem Martin | Nathalie Bozzolo | F. Prima
Source: MATEC Web of Conferences (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Strain-hardenability of new strengthened TRIP/TWIP titanium alloys A new Ti-Cr based alloy has been developed to reach a TWIP (TWinning Induced Plasticity) effect as the main deformation mechanism. This new composition, involving Fe addition, was derived from a classical TRIP/TWIP alloy Ti-8.5Cr-1.5Al (wt%) (TCA). The main objective is to achieve an optimized strength/hardenability combination by limiting the TRIP (TRansformation Induced Plasticity) effect whose critical resolved shear stress lowers the plasticity threshold. This new alloy Ti-7Cr-1Al-xFe (wt%) (TCAF) displays excellent mechanical properties, with an increased yield strength (with respect to TCA alloy), a very high work-hardening rate and an extremely high fracture strength (UTS=1415MPa), while maintaining an excellent ductility (ε=0.38 at fracture). Both mechanical (tensile tests) and microstructural characterization at different scales (EBSD, XRD) have been performed, evidencing a dense network of fine {332}&lt;113&gt; mechanical twins as well as the presence of stress-induced martensite plates at twins intersections, as a secondary mechanism. Twip ; Materials science ; Hardenability ; Plasticity ; Alloy ; Ultimate tensile strength ; Metallurgy ; Crystal twinning ; Ductility (Earth science) ; Work hardening ; Deformation mechanism ; Martensite ; Strain hardening exponent ; Composite material ; Microstructure Titanium Alloys Microstructure and Properties ; Intermetallics and Advanced Alloy Properties ; Advanced materials and composites
Authors: Mathew G. Pelletier | Rick K. Byler
Source: The journal of cotton science/Journal of cotton science (article, 2020-01-01)
Field: Materials Science — Polymers and Plastics

COTTON GINNERS HANDBOOK: Moisture Measurement Proper measurement of moisture content (MC) during the ginning process is crucial for proper management of a cotton gin. It is important to avoid producing wet cotton lint for the benefit of textile mills and because wet cotton is damaged in storage and degrades the value of cotton leading to a USDA-AMS classing color-grade that is no longer reflective of the actual color of cotton, which in turn is damaging to U.S. cotton commodity markets. Cotton stored at too high MC is unacceptable for marketing and is ineligible for placement into the Commodity Credit Corporation Marketing Assistance Loan Program. Additional problems occur with improper cotton moisture when ginning at excessively low MC, which results in cotton lint of lower quality with shorter fiber length and lower fiber length uniformity. Thus, use of moisture sensors are critical to ensure cotton gins produce bales at a MC that is safe for long term storage and transport. To assess cotton moisture, several meters are available from different manufacturers for the measurement of seed cotton and cotton lint MC. Some of these meters are portable and can be used with seed cotton or lint, whereas others are permanently installed. Some meters are suitable for automated moisture control in the gin. Lint ; Moisture ; Agricultural engineering ; Yarn ; Environmental science ; Fiber ; Water content ; Commodity ; Pulp and paper industry ; Mathematics ; Engineering ; Agronomy ; Business ; Materials science ; Composite material ; Mechanical engineering ; Biology Textile materials and evaluations
Authors: Alexei Khalyavkin | S. A. Makeev | Ali Salamekh | Aleksandra V. Ivanovskaya
Source: E3S Web of Conferences (article, 2020-01-01)
Field: Materials Science — General Materials Science

Analysis of boundary conditions in design circuits influence on the shaft line operating state The work investigates the bearing piece boundary conditions influence on the shaft line operating state, with respect to elastic properties of stern-tube bearings. It is noted that the shaft line is a part of the ship’s power plant and it is a shaft system, located on the same axis. Performance criterion is the deflection of the concentrated load in the design scheme`s action point, modeling the propeller`s weight, bearing parts reactions and the natural frequency of linear lateral oscillations. The design scheme itself is a beam, resting on two elastic supports with a k stiffness factor, with concentrated load acting on the one end and three variants of the boundary conditions: pinched, hinged and sliding supports on another one. The results of calculations are given for different boundary conditions and the stiffness factors of elastic supports. The diagram of natural frequencies of linear lateral oscillations of ship`s shafting line is presented. Deflection (physics) ; Stiffness ; Structural engineering ; Drive shaft ; Boundary value problem ; Engineering ; Bearing (navigation) ; Natural frequency ; Boundary (topology) ; Beam (structure) ; Control theory (sociology) ; Mechanics ; Physics ; Mathematics ; Mechanical engineering ; Vibration ; Computer science ; Classical mechanics ; Mathematical analysis ; Acoustics Material Properties and Applications ; Mechanical Engineering Research and Applications ; Advancements in Materials Engineering
Authors: Vicky Caron
Source: Corpus Université Laval (Université Laval) (article, 2020-01-01)
Field: Materials Science — Biomaterials

Étude de la livraison de nanoparticules au niveau de la barrière hémato-encéphalique La barrière hémato-encéphalique protège le cerveau de par son imperméabilité. Cela empêche toutefois le passage de potentielles molécules thérapeutiques contre les maladies du système nerveux central. En effet, à cause de leurs poids moléculaire et de leurs propriétés physicochimiques, nombreuses sont les molécules thérapeutiques développées par l’industrie pharmaceutique qui ne parviennent pas à atteindre leur cible au cerveau car elles sont bloquées par cette barrière. Les objectifs de mes travaux sont donc de valider puis de modifier des formulations d’immunoliposomes PEGylés pour améliorer leur devenir intracellulaire dans les cellules endothéliales des capillaires cérébraux qui forment la barrière hématoencéphalique. Après injection chez la souris, les liposomes atteignent les capillaires mais nous ne sommes pas parvenus à démontrer qu’ils y livrent leur contenu. Pour se faire, différentes formulations ont été testées in vitro et in vivo chez des modèles murins. Cela a permis de confirmer que les anticorps et les lipides formant les immunoliposomes atteignent bien les cellules endothéliales des capillaires du cerveau. Toutefois, le devenir du contenu des immunoliposomes reste incertain. Par la suite, l’idée était d’utiliser des fragments Fab’ à la surface des liposomes plutôt que des anticorps complets. Toutefois, la digestion des anticorps n’est pas complète et l’obtention de fragments Fab’ pures très complexe. Cela reste donc à améliorer avant de conjuguer les fragments aux liposomes. Political science Nanoparticle-Based Drug Delivery ; Pickering emulsions and particle stabilization ; Ginkgo biloba and Cashew Applications
Authors: Ziyi Cao | Gregery T. Buzzard | Jiayue Rong | Lyudmila V. Slipchenko | James R. W. Ulcickas | Charles A. Bouman | Garth J. Simpson
Source:  (preprint, 2020-11-23)
Field: Chemistry — Spectroscopy

Learning from computations and experiments simultaneously: Multi-agent consensus equlibrium (MACE) for improving chemical structure determination A framework for integration of empirically measured molecular structure, as inferred by moment of inertia, and <i>ab initio</i> structure prediction is presented to enable recovery of molecular structure representative of empirical conditions. Structural elucidation is a ubiquitous endeavor in chemistry, from crystal structure determination to molecular structure and conformational Mace ; Computation ; Computer science ; Psychology ; Algorithm Analytical Chemistry and Chromatography
Authors: Ziyi Cao | Gregery T. Buzzard | Jiayue Rong | Lyudmila V. Slipchenko | James R. W. Ulcickas | Charles A. Bouman | Garth J. Simpson
Source:  (preprint, 2020-11-23)
Field: Chemistry — Spectroscopy

Learning from computations and experiments simultaneously: Multi-agent consensus equlibrium (MACE) for improving chemical structure determination Mace ; Computation ; Computer science ; Psychology ; Algorithm Analytical Chemistry and Chromatography
Authors: Robert W. Epps
Source: NCSU Libraries Repository (North Carolina State University Libraries) (article, 2020-11-02)
Field: Materials Science — Materials Chemistry

Accelerated Lead Halide Perovskite Development by Autonomous Robotic Experimentation in Flow. EPPS, ROBERT WOOD.Accelerated Lead Halide Perovskite Development by Autonomous Robotic Experimentation in Flow (Under the direction of Dr. Milad Abolhasani) Lead (geology) ; Halide ; Perovskite (structure) ; Flow (mathematics) ; Computer science ; Process engineering ; Materials science ; Chemistry ; Chemical engineering ; Engineering ; Geology ; Mechanics ; Inorganic chemistry ; Physics Catalytic Processes in Materials Science
Authors: Relly Victoria Petrescu
Source: Journal of Mechatronics and Robotics (article, 2020-01-01)
Field: Materials Science — Biomaterials

Nanobotics Nanobotics (or Nanorobotics) is a field of emerging technology that deals with the creation of robots whose components are typically the size of a molecule or nanometer (10 -9 meters). More specifically, nanorobotics refers to nanotechnology, an engineering discipline that designs and builds nanorobots that have movement, processing and transmission characteristics, program execution, etc. Nanomachines are largely in the research and development phase, although some primitive and nanomotor molecular machines have already been tested. One example is a sensor with a switch of about 1.5 nanometers, capable of counting specific molecules in a chemical sample. The first useful applications of nanomachines could take place in the field of medical technology, where they could be used to identify and kill cancer cells. Another potential application is the detection of toxic chemicals as well as the measurement of their concentrations in the environment. Rice University has demonstrated a nano auto (nano car) developed through a chemical process, including Buckminsterfullerene for wheels. It is driven by controlling the temperature of the environment and by positioning a tunnel-effect microscope. Another definition describes nanobot as a machine capable of accurately interacting with nanoscale objects, or the ability to manipulate objects at this obvious scale. The vast majority of nanorobots are able to create copies/duplicates, that is to reproduce, these being called replicators. Medicine Diatoms and Algae Research
Authors: Mohammad Muqri | Eliezer Ochoa | Joshua De Piano | Michael Milford | Alan Galvan | Alireza Kavianpour
Source:  (article, 2020-09-10)
Field: Materials Science — Materials Chemistry

Survey and Analysis of Digital Thermoelectric-Generator-based Power System This paper is an attempt to report the modeling, design and build analysis of thermoelectric module (TEM) with realistic conditions for electrical power generation. It gives an insight to static and dynamic modeling with temperature dependent parametric variations and computation of various TEM parameters for modeling power generators. This paper demonstrates the undergraduate engineering technology student-driven research at our university in this arena. It depicts the application of the multi-agent approach which allowed the student team to take full control of the project from inception to completion. The team developed and built a microprocessor based prototype thermo-electric generator for waste heat recovery (module and heat exchanger), computed and analyzed the optimal power delivery by judicious material selection. Thermoelectric generator ; Modular design ; Controller (irrigation) ; Electricity generation ; Computer science ; Electric power ; Electric power system ; Waste heat ; Flexibility (engineering) ; Control engineering ; Power (physics) ; Engineering ; Heat exchanger ; Mechanical engineering ; Thermoelectric effect Advanced Thermoelectric Materials and Devices ; Energy Harvesting in Wireless Networks ; Hybrid Renewable Energy Systems
Authors: Fábio Henrique Pereira | Francisco Elânio Bezerra | Diego Oliva | Gilberto Francisco Martha de Souza | Ivan Eduardo Chabu | Josemir Belo dos Santos | Shigueru Nagao | Sílvio Ikuyo Nabeta
Source: Sensors (article, 2020-12-17)
Field: Materials Science — Materials Chemistry

Forecast Model Update Based on a Real-Time Data Processing Lambda Architecture for Estimating Partial Discharges in Hydrogenerator The prediction of partial discharges in hydrogenerators depends on data collected by sensors and prediction models based on artificial intelligence. However, forecasting models are trained with a set of historical data that is not automatically updated due to the high cost to collect sensors' data and insufficient real-time data analysis. This article proposes a method to update the forecasting model, aiming to improve its accuracy. The method is based on a distributed data platform with the lambda architecture, which combines real-time and batch processing techniques. The results show that the proposed system enables real-time updates to be made to the forecasting model, allowing partial discharge forecasts to be improved with each update with increasing accuracy. Data mining ; Computer science ; Set (abstract data type) ; Data processing ; Data set ; Real-time data ; Artificial intelligence ; Real-time computing ; Database High voltage insulation and dielectric phenomena ; Power Transformer Diagnostics and Insulation ; Magnetic Field Sensors Techniques
Authors: Amin Vahidi‐Moghaddam | Arman Rajaei | Moosa Ayati | Ramin Vatankhah | Mohammad Reza Hairi Yazdi
Source: arXiv (Cornell University) (preprint, 2020-12-02)
Field: Materials Science — Materials Chemistry

Adaptive prescribed-time disturbance observer using nonsingular terminal\n sliding mode control: Extended Kalman filter and particle swarm optimization In this paper, adaptive prescribed finite time stabilization of uncertain\nsingle-input and single-output nonlinear systems is considered in the presence\nof unknown states, unknown parameters, external load disturbance, and\nnon-symmetric input saturation. A prescribed finite time disturbance observer\nis designed to approximate the unmeasured external disturbance. Also, a\nnonsingular prescribed finite time terminal sliding mode control is proposed\nfor the closed-loop control of the system with the non-symmetric input\nsaturation. Extended Kalman filter algorithm is employed for the real-time\nestimations of the states and unknown parameters of the system. Moreover,\nparticle swarm optimization algorithm is used to obtain the design parameters\nof the proposed disturbance observer and controller. To show the performance of\ndesigned control scheme, the proposed approach is employed to guarantee\nprescribed finite time stabilization of nonlinear vibration of a nonlocal\nstrain gradient nanobeam. Finally, numerical simulations are performed to\nillustrate the effectiveness and performance of the developed adaptive control\nscheme for the vibration control of nanobeam in comparison to the conventional\nsliding mode control.\n Control theory (sociology) ; Particle swarm optimization ; Nonlinear system ; Terminal sliding mode ; Sliding mode control ; Controller (irrigation) ; Extended Kalman filter ; Mathematics ; Kalman filter ; Computer science ; Mathematical optimization ; Physics ; Control (management) Nonlocal and gradient elasticity in micro/nano structures ; Piezoelectric Actuators and Control ; Advanced MEMS and NEMS Technologies