jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Noemi Vanerio
Source: Pure Amsterdam UMC (article, 2020-01-01)
Field: Materials Science — Biomaterials

Innovative applications of an ex vivo vascular bioreactor Vascular bioreactors are ex vivo systems which host an isolated preserved blood vessel and can play an important role for investigating physiology and pathology of vessel disease. They can also be used for testing novel treatments, combining the advantages of in vivo and in vitro models. Despite their potential, the use of vascular bioreactors has not reached a relevant position in the testing strategies yet and it usually focusses on a single application. The aim of this dissertation was to promote general use of bioreactors in vascular medicine research as well in the development of new diagnostic tools, new devices and tissue-engineered solutions. This work first focused on using an innovative ex vivo vascular bioreactor to culture arteries from slaughterhouse animals under physiologically relevant conditions. Methods to alter arterial biomechanical properties were then explored and aneurysm pathology was induced and treated with a stent-graft in the bioreactor. The bioreactor was also used to investigate vasomotor responses and intravascular imaging effect on arteries. In addition, investigation of a novel vascular prosthesis paved the road for more extensive use of the bioreactor for tissue engineering applications. This research showed that a vascular bioreactor can be designed and operated as a versatile and comprehensive platform which potentially enables large scale use for research and medical device testing. Bioreactor ; Ex vivo ; Biomedical engineering ; In vivo ; Medicine ; Biology ; Biotechnology Electrospun Nanofibers in Biomedical Applications
Authors: Robert Winkler
Source: ChemRxiv (preprint, 2020-06-02)
Field: Chemistry — Spectroscopy

ProtyQuant: Comparing Label-Free Shotgun Proteomics Datasets Using Accumulated Peptide Probabilities &lt;p&gt;Comparing multiple label-free shotgun proteomics datasets requires various data processing and formatting steps, including peptide-spectrum matching, protein inference, and quantification. Finally, the compilation of results files into a format that allows for downstream analyses. ProtyQuant performs protein inference and quantification calculations, and combines the results of individual datasets into plain text tables. These are lightweight, human-readable, and easy to import into databases or statistical software. ProtyQuant reads validated pepXML from proteomic workflows such as the Trans-Proteomic Pipeline (TPP), which makes it compatible with many commercial and free search engines. For protein inference and quantification, a modified version of the PIPQ program (He et al. 2016) was integrated. In contrast to simple spectral-counting, PIPQ sums up peptide probabilities. For assigning peptides to proteins, three algorithms are available: Multiple Counting, Equal Division, and Linear Programming. The accumulated peptide probabilities (app) are used for both tasks, protein probability estimation, and quantification. ProtyQuant was tested using a reference dataset for label-free shotgun proteomics, obtained from different concentrations of 48 human UPS proteins spiked into yeast lysate. Compared to ProteinProphet, ProtyQuant detected up to 126 (15%) more proteins in the mixture, applying an equal false positive rate (FPR). Using the app values for label-free quantification showed suitable sensitivity and linearity. Strikingly, the app values represent a realistic measure of ‘Protein Presence,’ an integral concept of protein probability and quantity. ProtyQuant provides a graphical user interface (GUI) and scripts for console-based processing. It is available (GNU GLP v3) for Windows, Linux, and Docker from &lt;a href="https://bitbucket.org/lababi/protyquant/"&gt;https://bitbucket.org/lababi/protyquant/&lt;/a&gt;.&lt;/p&gt; Shotgun proteomics ; Computer science ; Quantitative proteomics ; Workflow ; Pipeline (software) ; Proteomics ; Label-free quantification ; Shotgun ; False positive paradox ; Data mining ; Artificial intelligence ; Chemistry ; Database ; Programming language Advanced Proteomics Techniques and Applications ; Biotin and Related Studies ; Machine Learning in Bioinformatics
Authors: Benjamin Ellyson
Source: Digital Collections of Colorado (Colorado State University) (article, 2020-12-31)
Field: Materials Science — Materials Chemistry

In-situ studies of strain rate effects on phase transformation and microstructural evolution in metastable β titanium alloys Materials science ; In situ ; Metallurgy ; Metastability ; Phase (matter) ; Strain (injury) ; Titanium ; Strain rate ; Transformation (genetics) ; Chemistry Titanium Alloys Microstructure and Properties ; Metal and Thin Film Mechanics ; Metallurgy and Material Forming
Authors: Daniel Andres‐Penares | Mojtaba Karimi Hábil | Alejandro Molina‐Sánchez | Carlos J. Zapata-Rodrı́guez | Juan P. Martínez‐Pastor | Juan F. Sánchez‐Royo
Source: Research Square (Research Square) (preprint, 2020-12-01)
Field: Materials Science — Materials Chemistry

Out-of-plane emission of trions in monolayer WSe2 revealed by whispering gallery modes of dielectric microresonators Abstract The manipulation of light emitted by two-dimensional semiconductors grounds forthcoming technologies in the field of on-chip communications. However, these technologies require from the so elusive out-of-plane photon sources to achieve an efficient coupling of radiated light into planar devices. Here we propose a versatile spectroscopic method that enables the identification of the out-of-plane component of dipoles due to the selective coupling of light emitted by in-plane and out-of-plane dipoles to the whispering gallery modes of spherical dielectric microresonators, in close contact to them. We have applied this method to demonstrate the existence of dipoles with an out-of-plane orientation in monolayer WSe 2 at room temperature, by means of micro-photoluminescent measurements, numerical simulations based on finite element methods, and ab-initio calculations. Experimental results and ab-initio calculations identify trions as the source responsible for this out-of-plane emission, opening new routes for realizing on-chip integrated systems with applications in information processing and quantum communications. Whispering-gallery wave ; Whispering gallery ; Dielectric ; Monolayer ; Plane (geometry) ; Materials science ; Optoelectronics ; Physics ; Optics ; Nanotechnology ; Resonator ; Geometry 2D Materials and Applications ; Perovskite Materials and Applications ; Molecular Junctions and Nanostructures
Authors: Patrick M. Yarbrough
Source: Digital Collections of Colorado (Colorado State University) (article, 2020-05-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

High frequency magnetization dynamics affecting parallel pumping, reﬂectivity and thermal properties of magnets The world is increasingly dependent on magnetic systems for many devices, from data storage in hard disk drives to information transfer and logical operations, to signal processing and more.As these technologies proliferate throughout our lives, the next generation of magnetic devices are in high demand as the amount of information and data to be stored, transferred, etc. skyrockets.The large tunability of many magnetic systems make them ideal candidates for meeting this demand as fabrication techniques on the nanometer scale become more sophisticated.In this dissertation, the magnetization dynamics for various nanometer-scale magnetic systems are studied.For example, as the band gap from 1-10 GHz is filled with more wireless devices, there is a desire to develop new technologies that can operate in the frequency regime from 10-1000 GHz.In chapter II, we show how alternating stacks of ultrathin layers of ferromagnetic and non-magnetic materials can exhibit resonance frequencies in the far-infrared frequency regime.As magnetic systems are fabricated on smaller and smaller scales, it is important to understand how different interactions affect the performance of these devices.In chapter III, we explore how the dipolar field in a rectangular nanostripe affects the spin waves that are excited.These spin wave excitations are of interest because they provide an alternative to electronic-based devices, which are susceptible to Joule heating at small length scales.We explore how a rectangular ferromagnetic nanostripe in the parallel pumping geometry can produce off-resonance spin waves as well as backward volume magnetostatic spin waves.Another effect which is observed in ultrathin magnetic films is the interfacial antisymmetric exchange interaction, which competes with the symmetric exchange interaction to iii dramatically alter the spectrum of excited spin waves.While this interaction has been known for several decades, there have been few studies on these systems when thermal fluctuations are included.In chapter IV we explore how these thermal fluctuations affect the average magnetization in an ultrathin film with and without the antisymmetric exchange interaction.At the end of each chapter, we present conclusions and a future outlook for the potential applications of each magnetic system. Magnet ; Magnetization ; Thermal ; Materials science ; Dynamics (music) ; Magnetization dynamics ; Condensed matter physics ; Physics ; Mechanical engineering ; Magnetic field ; Engineering ; Thermodynamics ; Acoustics Magnetic Properties of Alloys ; Electric Motor Design and Analysis ; Magnetic Properties and Applications
Authors: Michael R. Kozak
Source:  (article, 2020-09-10)
Field: Chemistry — Physical and Theoretical Chemistry

A Self-administered Gage Analysis Intervention and Assessment A solo gage repeatability and reproducibility (gage r and r) study exercise was developed and individually administered to a population of Engineering Technology students. This paper includes the intervention procedure that was developed to self-guide a student through the performance and interpretation of a gage r and r. This paper also presents the assessment used to determine the effectiveness of the exercise. Students' comments regarding difficulties pertaining to the performance of the exercise are presented. The gage intervention was moderately successful as judged by the assessment tool. Repeatability ; Reproducibility ; GRASP ; Metrology ; Computer science ; Dimension (graph theory) ; Simulation ; Artificial intelligence ; Statistics ; Mathematics ; Software engineering Various Chemistry Research Topics ; Engineering Education and Pedagogy ; Science Education and Pedagogy
Authors: Mitchell Swyt | Buchanan, Kristen | Ross, Kate | Menoni, Carmen
Source: Digital Collections of Colorado (Colorado State University) (article, 2020-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Growth and characterization of ultra-low damping Co₂₅Fe₇₅ thin films This thesis focuses on the growth and characterization of ultra-low damping Co25Fe75 thin films. Ultra-low damping in a metal is of interest for the design of new spintronic devices because this offers the opportunity to move both electrons and spin waves over appreciable distances. In this work, the effects of seed and capping layers on the damping parameter and magnetization are investigated. A series of thin films were deposited using DC magnetron sputtering. A combination of X-ray reflectometry (XRR), vibrating sample magnetometry (VSM), and ferromagnetic resonance spectroscopy (FMR) were used to determine the film quality, saturation magnetization, and damping parameters of each film. The results show that the Ta seed layers promoted smooth film growth for Co25Fe75, but direct interfaces with Ta or Pt resulting in enhanced damping. Cu spacer layers can be used to disrupt the enhancement but promote rough film growth for the studied sample growth conditions. Damping values in agreement with published results were achieved for two films from the set, with α=0.0064 ± 0.0004 for Ta/Co25Fe75 and α=0.0063 ± 0.0011 for Ta/Cu/Co25Fe75/Cu/Ta. Characterization (materials science) ; Materials science ; Thin film ; Engineering physics ; Nanotechnology ; Physics Magnetic and transport properties of perovskites and related materials ; Magnetic properties of thin films ; Heusler alloys: electronic and magnetic properties
Authors: Serhii Morhun
Source: Проблеми обчислювальної механіки і міцності конструкцій (article, 2020-02-20)
Field: Materials Science — General Materials Science

GAS TURBINE ENGINES IMPELLERS FORCED VIBRATION AND STRESS-STRAIN STATE INVESTIGATION The method of the gas turbine engine impeller forced vibration and stress-strain state parameters calculation is given. Using the finite element method, a refined mathematical model was developed for the several types of impellers most widespread in the practice of gas turbine engines building. The developed mathematical model takes into consideration the impeller blades geometric parameters and the construction of blades connectors. The results of its forced vibration frequencies calculation, caused by the influence of non-stationary gas flow are given for different types of the blades connectors. The dependencies of the impeller blades stress-strain state from the value its feather geometric perameters have been studied too.&#x0D; Impeller ; Vibration ; Finite element method ; Structural engineering ; Stress (linguistics) ; Gas turbines ; Mechanical engineering ; Turbine blade ; Engineering ; Stress–strain curve ; Flow (mathematics) ; Turbine ; Blade (archaeology) ; Mechanics ; Acoustics ; Physics Material Properties and Applications ; Engineering Diagnostics and Reliability ; Mechanical Systems and Engineering
Authors: Oswaldo Rojas | Manuel G. Forero | José Manuel Menéndez | Angharad Jones | Walter Dewitte | J. A. H. Murray
Source: Applied Sciences (article, 2020-11-28)
Field: Materials Science — Biomaterials

Segmentation of Meristem Cells by an Automated Optimization Algorithm Meristem cells are irregularly shaped and appear in confocal images as dark areas surrounded by bright ones. Images are characterized by regions of very low contrast and absolute loss of edges deeper into the meristem. Edges are blurred, discontinuous, sometimes indistinguishable, and the intensity level inside the cells is similar to the background of the image. Recently, a technique called Parametric Segmentation Tuning was introduced for the optimization of segmentation parameters in diatom images. This paper presents a PST-tuned automatic segmentation method of meristem cells in microscopy images based on mathematical morphology. The optimal parameters of the algorithm are found by means of an iterative process that compares the segmented images obtained by successive variations of the parameters. Then, an optimization function is used to determine which pair of successive images allows for the best segmentation. The technique was validated by comparing its results with those obtained by a level set algorithm and a balloon segmentation technique. The outcomes show that our methodology offers better results than two free available state-of-the-art alternatives, being superior in all cases studied, losing 9.09% of the cells in the worst situation, against 75.81 and 25.45 obtained in the level set and the balloon segmentation techniques, respectively. The optimization method can be employed to tune the parameters of other meristem segmentation methods. Segmentation ; Scale-space segmentation ; Artificial intelligence ; Image segmentation ; Segmentation-based object categorization ; Computer science ; Computer vision ; Pattern recognition (psychology) ; Mathematical morphology ; Set (abstract data type) ; Parametric statistics ; Level set method ; Meristem ; Process (computing) ; Mathematics ; Image (mathematics) ; Image processing ; Biology Diatoms and Algae Research ; Genomics and Phylogenetic Studies ; Cell Image Analysis Techniques
Authors: Hua Chen | Olivier Pinaud | M. Tahir
Source: arXiv (Cornell University) (preprint, 2020-05-28)
Field: Materials Science — Materials Chemistry

A simple real-space scheme for periodic Dirac operators We address in this work the question of the discretization of two-dimensional periodic Dirac Hamiltonians. Standard finite differences methods on rectangular grids are plagued with the so-called Fermion doubling problem, which creates spurious unphysical modes. The classical way around the difficulty used in the physics community is to work in the Fourier space, with the inconvenience of having to compute the Fourier decomposition of the coefficients in the Hamiltonian and related convolutions. We propose in this work a simple real-space method immune to the Fermion doubling problem and applicable to all two-dimensional periodic lattices. The method is based on spectral differentiation techniques. We apply our numerical scheme to the study of flat bands in graphene subject to periodic magnetic fields and in twisted bilayer graphene. Dirac comb ; Fourier transform ; Spurious relationship ; Discretization ; Hamiltonian (control theory) ; Simple (philosophy) ; Fourier series ; Mathematics ; Fast Fourier transform ; Bilayer graphene ; Physics ; Dirac fermion ; Mathematical analysis ; Quantum mechanics ; Fermion ; Graphene ; Algorithm ; Dirac spinor ; Mathematical optimization Graphene research and applications ; Topological Materials and Phenomena ; Spectral Theory in Mathematical Physics
Authors: Mitrofan Curti
Source: Data Archiving and Networked Services (DANS) (article, 2020-11-23)
Field: Materials Science — Electronic, Optical and Magnetic Materials

A spectral element based framework for efficient computation of electromechanical problems: applied to magnetic, electric, thermal and eddy current field modelling in electrical machines A spectral element based framework for efficient computation of electromechanical problems Eddy current ; Computation ; Thermal ; Mechanical engineering ; Finite element method ; Magnetic field ; Current (fluid) ; Field (mathematics) ; Electrical engineering ; Electrical current ; Engineering ; Physics ; Computer science ; Structural engineering ; Mathematics ; Algorithm ; Meteorology Magnetic Properties and Applications ; Electric Motor Design and Analysis ; Induction Heating and Inverter Technology
Authors: Gulnar Mirzayeva | Vusala Rzayeva
Source: Technology audit and production reserves (article, 2020-10-30)
Field: Materials Science — Materials Chemistry

Analysis free oscillations of a non-homogeneous pipe along's thickness and length, taking into account the resistance of the external environment Structural elements made of heterogeneous natural and artificial materials are widely used in the construction of modern building complexes and in many other areas. Among them is the use of boards and shells of different configurations. Currently, one of the most important requirements for designers and accountants is to properly assess the mechanical properties of the material of the structural element and the impact of the environment in contact during operation. Taking these into account, the mathematical solution of the problem becomes difficult, and if not, serious mistakes can be made. One of the most problematic places is considering the resistance of the external environment.Objects of research are modern pipes exposed to the external environment.In the paper is analysis Pasternak is one of the mathematical models that accurately reflects the elastic real properties of the environment, the model Winkler, which is characterized by two constants, the model of Karnet and the model of Rjanitsin. And is analysis their effected.In the course of the research, the method of separation of variables and then Bubnov-Galerkin method is used, which explain relationship between the dimensionless value of frequency, the parameters that characterize the non-homogeneous of the base, and the pipe. The selection of special frequencies is carried out by selecting the corresponding special equation and boundary conditions. There are nonlinear algebraic equations and their solution using computer technology. It is shown that when the mechanical properties of the pipe vary in length, the above solution method does not work and the determination of the characteristic parameters must be performed using other approximate analytical methods. In engineering practice, it is usually sufficient to find the basic tone of the frequency. As a result of the research it is shown that the external environment effects are important for non-homogeneous pipe and should be considered in the design of the structure-ground interaction. In the future, the proposed approach and should be considered in the design of the structure non-homogenous pipe interaction. Dimensionless quantity ; Boundary value problem ; Nonlinear system ; Algebraic equation ; Base (topology) ; Galerkin method ; Work (physics) ; Finite element method ; Homogeneous ; Computer science ; Mathematical analysis ; Mechanical engineering ; Mathematics ; Engineering ; Structural engineering ; Mechanics ; Physics ; Statistical physics Structural mechanics and materials ; Engineering and Agricultural Innovations ; Mechanical Systems and Engineering
Authors: Brett M. Savoie
Source: Bulletin of the American Physical Society (article, 2020-03-02)
Field: Materials Science — Materials Chemistry

A Transfer Learning Framework for Improving Property Prediction, Interpretability, and Chemical Discovery from Scarce Datasets Interpretability ; Property (philosophy) ; Computer science ; Transfer of learning ; Artificial intelligence ; Machine learning ; Data science Machine Learning in Materials Science ; Machine Learning and Data Classification ; Computational Drug Discovery Methods
Authors: Brahim Benyahia | Paul Danny Anandan | Chris D. Rielly
Source:  (article, 2020-11-10)
Field: Materials Science — Materials Chemistry

Optimal trajectory tracking control of batch crystallization process based on reinforcement learning The control of the particle size distribution, crystal habit, and crystal purity is crucial in most crystallization processes to meet the targeted critical quality attributes of the final product. Over the last two decades, several model-free strategies, such as supersaturation control and direct nucleation control, and model-based techniques, such as model predictive control, have been developed and implemented in a wide range of scientific and industrial sectors, particularly the pharmaceutical industry. Despite the significant progress, there is still an increasing demand for more advanced, versatile, robust, and cost-effective optimization and control technologies for both batch and continuous crystallization processes to ensure, through real-time trajectory tracking control, high product quality and reduce batch-to-batch variation and wastes. A novel optimal trajectory tracking control strategies of a batch cooling crystallization processes based on reinforcement learning is presented. The cooling crystallization of paracetamol in water was used as a case study. A model-based technique is implemented, using a dynamic mathematical model validated elsewhere, to reduce the experimental burden and explore wider design and operating spaces. The main objective is to achieve a large crystal size and reduce the deviation from a targeted final yield and coefficient of variation. Several training strategies and reward functions were tested to help achieve robust optimal training of the agent. The agents, with the best training features, were validated against different particle size, temperature, and supersaturation trajectories, then compared to benchmark control techniques, such as supersaturation control and model predictive control. Benchmark (surveying) ; Model predictive control ; Optimal control ; Reinforcement learning ; Computer science ; Supersaturation ; Trajectory ; Crystallization ; Process (computing) ; Process control ; Process engineering ; Control theory (sociology) ; Control engineering ; Control (management) ; Mathematical optimization ; Engineering ; Artificial intelligence ; Mathematics Crystallization and Solubility Studies ; Process Optimization and Integration