jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Koichi Matsuo
Source: Nihon Kessho Gakkaishi (article, 2018-08-30)
Field: Materials Science — Materials Chemistry

Development of Vacuum-Ultraviolet Circular-Dichroism Spectrophotometer Using Synchrotron Radiation and Structural Analysis of Biomolecules A vacuum-ultraviolet circular-dichroism spectroscopy using synchrotron radiation greatly expands the utility of chiroptical technique for the structural analysis of biomolecules by combining with theoretical analysis and bioinformatics. This spectroscopy provides the structural dynamics, intramolecular hydrogen bonds, and hydrations of saccharides, and also successfully estimates the secondary structure contents, numbers of segments, and sequences of native proteins and non-native proteins such as membrane-bound proteins. The circular dichroism theory of protein discloses the local structures of the amyloid fibrils at the molecular level. This synchrotron-radiation spectroscopy is opening a new filed in the glycobiology and structural biology. Synchrotron radiation ; Biomolecule ; Vacuum ultraviolet ; Circular dichroism ; Materials science ; Radiation ; Optics ; Ultraviolet ; Analytical Chemistry (journal) ; Physics ; Chemistry ; Crystallography ; Nanotechnology ; Chromatography Enzyme Structure and Function ; Protein Structure and Dynamics ; Glycosylation and Glycoproteins Research
Authors: Levent Başayığıt | Sinan Demir | Yusuf Uçar | Burhan Kara
Source: Zenodo (CERN European Organization for Nuclear Research) (article, 2018-08-02)
Field: Chemistry — Analytical Chemistry

Spectral Mixture Model Applied To Cannabis Parcel Determination Many research projects require accurate delineation of the different land cover type of the agricultural area. Especially it is critically important for the definition of specific plants like cannabis. However, the complexity of vegetation stands structure, abundant vegetation species, and the smooth transition between different seconder section stages make vegetation classification difficult when using traditional approaches such as the maximum likelihood classifier. Most of the time, classification distinguishes only between trees/annual or grain. It has been difficult to accurately determine the cannabis mixed with other plants. In this paper, a mixed distribution models approach is applied to classify pure and mix cannabis parcels using Worldview-2 imagery in the Lakes region of Turkey. Five different land use types (i.e. sunflower, maize, bare soil, and cannabis) were identified in the image. A constrained Gaussian mixture discriminant analysis (GMDA) was used to unmix the image. In the study, 255 reflectance ratios derived from spectral signatures of seven bands (Blue-Green-Yellow-Red-Rededge-NIR1-NIR2) were randomly arranged as 80% for training and 20% for test data. Gaussian mixed distribution model approach is proved to be an effective and convenient way to combine very high spatial resolution imagery for distinguishing cannabis vegetation. Based on the overall accuracies of the classification, the Gaussian mixed distribution model was found to be very successful to achieve image classification tasks. This approach is sensitive to capture the illegal cannabis planting areas in the large plain. This approach can also be used for monitoring and determination with spectral reflections in illegal cannabis planting areas. Cannabis ; Environmental science ; Petroleum engineering ; Engineering ; Computer science ; Psychology ; Psychiatry Spectroscopy and Chemometric Analyses ; Thermodynamic properties of mixtures
Authors: Ali Mohsin Al-Juboori
Source: Journal of Education College Wasit University (article, 2018-01-16)
Field: Chemistry — Analytical Chemistry

An Efficient Method for Texture Feature Extraction and Recognition based on Contourlet Transform and Canonical Correlation Analysis Feature extraction is an important processing step in texture classification. For feature extraction in contourlet domain, statistical features for blocks of subband are computed. In this paper, we present an efficient feature vector extraction method for texture classification. For more discriminative feature a canonical correlation analysis method is propose for feature vector fused to the different sample of texture in the same cluster. The KNN (K-Nearest Neighbor) classifier is utilizing to perform texture classification.&#x0D; Pattern recognition (psychology) ; Contourlet ; Artificial intelligence ; Feature extraction ; Discriminative model ; Canonical correlation ; Computer science ; Classifier (UML) ; k-nearest neighbors algorithm ; Feature vector ; Feature (linguistics) ; Texture (cosmology) ; Correlation ; Mathematics ; Image (mathematics) ; Wavelet transform ; Wavelet Spectroscopy and Chemometric Analyses ; Advanced Image Fusion Techniques ; Image Retrieval and Classification Techniques
Authors: Rubens Chinali Canarim
Source: LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) (article, 2018-01-19)
Field: Materials Science — Materials Chemistry

Influência da friabilidade dos grãos abrasivos de rebolos de CBN na retificação cilíndrica externa de mergulho do aço AISI 4340 Submitted by Rubens Chinali Canarim null (rubenscanarim@hotmail.com) on 2018-02-05T12:10:04Z&#13;\nNo. of bitstreams: 1&#13;\nTESE FINAL ENTREGA.pdf: 2914880 bytes, checksum: e1503c15204b7dbc230efbbea4f1320d (MD5) Materials science Metal Alloys Wear and Properties ; Advanced Surface Polishing Techniques ; Metal and Thin Film Mechanics
Authors: Malachi Griffith
Source: Faculty of 1000 Research Ltd (article, 2018-01-01)
Field: Chemistry — Spectroscopy

Referee report. For: drawProteins: a Bioconductor/R package for reproducible and programmatic generation of protein schematics [version 1; referees: 2 approved] Schematic ; Component (thermodynamics) ; Field (mathematics) Advanced Proteomics Techniques and Applications ; Advanced Biosensing Techniques and Applications ; Bioinformatics and Genomic Networks
Authors: Kevin Deweese
Source: eScholarship (California Digital Library) (article, 2018-01-01)
Field: Materials Science — Polymers and Plastics

Bridging the Theory-Practice Gap of Laplacian Linear Solvers Solving Laplacian linear systems is an important task in a variety of practical and theoretical applications. Laplacians of structured graphs, such as two and three dimensional meshes, have long been important in finite element analysis and image processing. More recently, solving linear systems on the Laplacians of large graphs without mesh-like structure has emerged as an important computational task in network analysis. A number of theoretical solvers with good asymptotic complexity have been proposed over the past couple decades, but these ideas have not made their way into practical solvers. Nor is it clear that a class of challenging problems exist which would benefit from asymptotically fast solvers. Yet it seems that one of the following should be true: either existing solvers have tighter Big-O bounds than currently believed, or there are some problems where recent asymptotically fast (but theoretical) algorithms should be useful.This work considers the latter possibility; we aim to bridge the gap between theoretical and practical Laplacian algorithms by experimenting with Laplacian solvers and by searching for difficult test problems. We examine the performance of existing algorithms for solving Laplacian linear systems and identify the strengths and weaknesses of different methods on different test problems. We perform an extensive evaluation of the KOSZ solver, one of the recently proposed Õ(m) Laplacian algorithms. We test various extensions of KOSZ which we propose to try and improve its performance in practice. We introduce heavy path graphs, a novel class of graphs for experimenting with Laplacian solvers.To challenge existing solver implementations, we propose the use of genetic algorithms to create difficult test graphs for existing solvers. At the same time, these algorithms could be used to find graphs with good performance for recently proposed solvers. Searching for graphs which satisfy both objectives could be instrumental towards bridging the theory-practice gap of Laplacian solvers. We demonstrate the successful evolution of graphs which are difficult for conjugate gradient with diagonal scaling, while relatively simple for KOSZ. Such graph evolution techniques could be useful for finding graphs with a variety of combinatorial properties. Solver ; Computer science ; Variety (cybernetics) ; Bridging (networking) ; Class (philosophy) ; Laplace operator ; Polygon mesh ; Theoretical computer science ; Laplacian matrix ; Path (computing) ; Algorithm ; Graph ; Mathematics ; Artificial intelligence Dendrimers and Hyperbranched Polymers ; Metal-Organic Frameworks: Synthesis and Applications ; Conducting polymers and applications
Authors: Luciano Marques Brito Reis | Lúcio Flávio de Albuquerque Campos
Source: Portuguese National Funding Agency for Science, Research and Technology (RCAAP Project by FCT) (article, 2018-03-11)
Field: Chemistry — Analytical Chemistry

Detecção de Lesões de Câncer de Pele Utilizando Análise de Componentes Independentes e Análise Discriminante Linear O câncer de pele vem se configurando como o mais frequente em toda a população brasileira. A exposição excessiva à radiação solar é o fator principal de risco. Diante dessa situação, o método mais simples para a diminuição das taxas de incidência e mortalidade relativas ao câncer de pele é o diagnóstico precoce. Este trabalho tem como objetivo apresentar um método diagnóstico auxiliado por computador baseado em processamento de imagens para detecção de lesões de câncer de pele melanoma e não melanoma utilizando Análise de Componentes Independente (ICA) para extração de características, o algoritmo de máxima Relevância e Mínima Redundância (mRMR) para redução de dimensionalidade e Análise Discriminante Linear (LDA) para a classificação das imagens. A capacidade do método foi avaliada pela técnica de validação cruzada, e atingiu 100% de acurácia, 100% de sensibilidade e 100% de especificidade ao analisar todas as amostras. Physics ; Medicine ; Mathematics Spectroscopy and Chemometric Analyses ; Microbial Inactivation Methods ; Cutaneous Melanoma Detection and Management
Authors: Larissa Leal Moura
Source: LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) (article, 2018-02-16)
Field: Chemistry — Analytical Chemistry

Agrupamento espectral através de grafos Laplacianos e uma aplicação no cultivo da soja. Submitted by Larissa Moura null (moura.larie@gmail.com) on 2018-02-26T11:39:11Z&#13;\nNo. of bitstreams: 1&#13;\nmoura_larissa_sjrp.pdf: 1591130 bytes, checksum: 7997e476e0c0da8c86b51d6ce91c8898 (MD5) Physics ; Humanities ; Mathematics ; Art Spectroscopy and Chemometric Analyses ; Color Science and Applications
Authors: Jacob Ethier
Source: W&M Publish (College of William & Mary) (article, 2018-01-01)
Field: Chemistry — Spectroscopy

Proton Spin Structure From Monte Carlo Global Qcd Analyses Although significant progress has been made in recent years in understanding the composition of the proton's spin from its quark and gluon constituents, a complete picture has yet to emerge. Such information is encoded in spin-dependent parton distribution functions (PDFs) that, as a consequence of being inherently nonperturbative, must be extracted through global QCD analyses of polarized lepton-nucleon and proton-proton collisions. Experiments that measure a final state hadron from these reactions are particularly useful for separating the individual quark and anti-quark polarizations, but require knowledge of parton-to-hadron fragmentation functions (FFs) to describe theoretically. In this thesis, we present a new approach to global QCD analyses, that were performed recently by the Jefferson Lab Angular Momentum (JAM) Collaboration to determine the spin PDFs and FFs from deep inelastic scattering (DIS), semi-inclusive DIS, and single inclusive electron-positron annihilation observables. While previous global QCD studies typically used a single $\chi^2$ minimization procedure, the JAM Collaboration applies a robust Monte Carlo fitting methodology to extract the central values and uncertainties of the relevant distributions. The results from these JAM global QCD analyses, which include a first ever simultaneous fit of the spin PDFs and FFs, resolve a long-standing puzzle regarding the strange quark polarization and provide new information about the proton spin structure. Monte Carlo method ; Physics ; Quantum chromodynamics ; Proton ; Statistical physics ; Nuclear physics ; Particle physics ; Mathematics ; Statistics Advanced NMR Techniques and Applications ; Nuclear physics research studies ; Advanced Chemical Physics Studies
Authors: Hiroshi Madokoro | Alexei Miassoedov | Thomas S. Schulenberg
Source: Journal of Nuclear Engineering and Radiation Science (article, 2018-11-26)
Field: Materials Science — Materials Chemistry

Coupling of a Reactor Analysis Code and a Lower Head Thermal Analysis Solver Due to the recent high interest on in-vessel melt retention (IVR), development of detailed thermal and structural analysis tool, which can be used in a core-melt severe accident, is inevitable. Although RELAP/SCDAPSIM is a reactor analysis code, originally developed for U.S. NRC, which is still widely used for severe accident analysis, the modeling of the lower head is rather simple, considering only a homogeneous pool. PECM/S, a thermal structural analysis solver for the reactor pressure vessel (RPV) lower head, has a capability of predicting molten pool heat transfer as well as detailed mechanical behavior including creep, plasticity, and material damage. The boundary condition, however, needs to be given manually and thus the application of the stand-alone PECM/S to reactor analyses is limited. By coupling these codes, the strength of both codes can be fully utilized. Coupled analysis is realized through a message passing interface, OpenMPI. The validation simulations have been performed using LIVE test series and the calculation results are compared not only with the measured values but also with the results of stand-alone RELAP/SCDAPSIM simulations. Nuclear engineering ; Solver ; Materials science ; Heat transfer ; Head (geology) ; Reactor pressure vessel ; Computer science ; Coupling (piping) ; Thermal analysis ; Thermal ; Mechanical engineering ; Mechanics ; Physics ; Engineering ; Composite material ; Thermodynamics Nuclear Materials and Properties ; Nuclear reactor physics and engineering ; Nuclear Engineering Thermal-Hydraulics
Authors: Ahmed H. A | Ibrahim Yusuf Alkali
Source: Zenodo (CERN European Organization for Nuclear Research) (article, 2018-11-30)
Field: Chemistry — Organic Chemistry

In silico molecular docking studies of some phytochemicals against peroxisome-proliferator activated receptor gamma (PPAR-γ) Peroxisome Proliferator-Activated Receptor-γ (PPAR-γ) is a ligand-activated transcription factor and a member of the nuclear receptor superfamily that regulate the gene expression of proteins involved in glucose, lipid metabolism, adipocyte proliferation and differentiation and insulin sensitivity. Thiazolidinediones (TZDs) are one important class of synthetic agonists of PPAR-γ. TZDs are antidiabetic agents that target adipose tissue and improve insulin sensitivity, and they are currently being used in the treatment of type 2 diabetes. The study was carried out in order to discover new phytochemicals that have the ability to stimulate the PPAR-γ using molecular docking studies. AutoDock vina was used as molecular-docking tool in order to carry out the docking simulations. Nine phytochemicals namely plumbagin, quercetin, isovitexin, mangiferin, syringin, lupe-20-ene-3-one, purine 2, 6-dione, diosmetin and β sitosterol and pioglitazone a standard drug were docked against PPAR-γ using AutoDock vina and the results were analyzed using binding affinity. The results revealed that the compounds have significant binding affinity towards the PPAR-γ comparable to pioglitazone the standard drug. Based on the findings of this study these phytochemicals can serve as source of antidiabetic drugs via the mechanism of inhibition of PPAR-γ. Peroxisome proliferator-activated receptor ; Docking (animal) ; In silico ; Receptor ; Peroxisome ; Peroxisome proliferator ; Peroxisome proliferator-activated receptor gamma ; Chemistry ; Pharmacology ; Peroxisome proliferator-activated receptor alpha ; Computational biology ; Nuclear receptor ; Biology ; Biochemistry ; Medicine ; Transcription factor ; Gene Synthesis and biological activity ; Peroxisome Proliferator-Activated Receptors
Authors: Justin Conrad
Source: Iowa State University Digital Repository (Iowa State University) (article, 2018-01-01)
Field: Chemistry — Physical and Theoretical Chemistry

Keeping your ion chemistry from a fragmented perspective Ionic liquids (ILs) are an intriguing class of compounds, belonging to a subset of molten ionic salts with melting points near or less than 100 ºC. There has been much excitement and promise in recent years over the possible applications of ILs, such as solvent-free-electrolyte solutions, reusable solvents for carbon dioxide capture, and energetic ionic liquids for use as explosives and propellants. Having intriguingly well-balanced intermolecular and ionic interactions, small changes in quantum-based effects (such as dispersion or charge transfer) can play important roles in IL properties. ILs are thereby challenging to model classically, and require ab initio based methods to be modeled accurately. This dissertation looks at different ab initio based approaches to modeling the interactions found in ionic liquids, and the roles fragmentation methods are filling in moving toward accurate and cost efficient methods for modeling ionic liquids. Perspective (graphical) ; Chemistry ; Computer science ; Artificial intelligence History and advancements in chemistry ; Various Chemistry Research Topics
Authors: Jayalath Abeywardhana Mudiyanselage Madawa Abeywardhana
Source: DigitalCommons@UTEP (The University of Texas at El Paso) (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

Massively Parallel Computational Studies Of Material Response At High Strain Rate Deformation Large scale molecular dynamics (MD) simulations are now commonly utilized to study materials at extreme conditions: high pressure and/or temperatures and ultra-high strain rates of deformation. A variety of emerging architectures such as general purpose graphics processing units (GP-GPU) and many-integrated core (MIC) architecture as well as new execution models have changed the traditional approach of high-performance computing. ExMatEx, the DoE initiative for enabling exa-scale (10^18 flops) performance in scientific applications, has developed several proxy applications to facilitate co-design of novel algorithms and hardware by software developers and microchip vendors.\nWe have used CoMD, a proxy application for classical MD, to investigate load balancing of shock wave simulation problems in various platforms as well as how best to improve performance of embedded-atom method (EAM) force evaluation kernels in GPUs. We also have implemented quasi-isentropic (QI) compression and expansion model in Los Alamos MD code SPaSM. QI uniaxial compression is achieved by incorporating a strain rate function in the position and velocity equations of motion. In this new formalism the change in internal energy is exactly equal to the work done during the compression or expansion.\nLarge-Scale molecular dynamics (MD) simulations comprising 4 to 34 million atoms were performed to systematically study the poorly understood interplay between initial dislocation density and strain rate on deformation twinning in bcc metals. Using tantalum as a test case, for which a large body of experimental data exist. The atomic interactions were modeled employing an embedded-atom method (EAM) potential of Ta, we examined both compressive and tensile deformation at strain rates in the range of 10^8 - 10^11 1/s . At these high-strain rates, twin nucleation thresholds can clearly be measured. Under both expansion and compression, deformation twinning increases with strain rate for strain-rates &gt; 10^9 1/s. Massively parallel ; Strain (injury) ; Deformation (meteorology) ; Computer science ; Strain rate ; Parallel computing ; Materials science ; Composite material ; Biology High-Velocity Impact and Material Behavior ; Structural Response to Dynamic Loads ; Geotechnical and Geomechanical Engineering
Authors: V. Belko
Source: Electronic scientific archive of UrFU (Ural Federal University) (article, 2018-05-22)
Field: Chemistry — Physical and Theoretical Chemistry

Modeling of thermal transport in electronic nano-devices using methods of molecular dynamics Nano- ; Dynamics (music) ; Molecular dynamics ; Nanotechnology ; Thermal ; Materials science ; Statistical physics ; Chemistry ; Physics ; Thermodynamics ; Computational chemistry Advanced Physical and Chemical Molecular Interactions ; Surface and Thin Film Phenomena ; Chemical and Physical Properties of Materials
Authors: Andrei Rykhlevskii
Source: IDEALS (University of Illinois Urbana-Champaign) (article, 2018-04-24)
Field: Materials Science — Materials Chemistry

Advanced online fuel reprocessing simulation for thorium-fueled molten salt breeder reactor Current interest in advanced nuclear energy and MSR concepts has enhanced demand in building the tools to analyze these systems. This thesis introduces a Python script, SaltProc, which simulates MSR online reprocessing by modeling the changing isotopic composition of an irradiated fuel salt. SaltProc couples with the Monte Carlo code, SERPENT 2, for neutron transport and depletion calculations. SaltProc capabilities include a generic geometry capable of modeling multi-region and multi-flow systems, time-dependent feeds and removals, and specific separation efficiency for each element or isotope removal flow. Generally applicable capabilities are illuminated in this thesis in three applied problems: (1) simulating the startup of a thorium-fueled MSBR fuel cycle to find equilibrium fuel composition (when multiplication factor of the full-core model and the U-233 concentration in the fuel salt are invariant in time); (2) determining the effect of the fuel salt irradiation with online reprocessing on MSBR operations; and (3) estimating MSBR fuel cycle performance by computing the Th-232 feed rate over 20 years of operation and comparing with available data.\n\nIn the first application, full-core depletion in the MSBR demonstrated that (1) equilibrium fuel composition could be achieved after 16 years and (2) the multiplication factor stabilizes after 6 years of operation. In the second application, fuel salt irradiation with simulated fission product removal and fissile/fertile feed causes considerable neutron energy spectrum hardening; this spectral shift has a problematic impact on safety parameters (e.g., temperature reactivity feedback, reactivity control system worth). In the third application, the average Th-232 feed rate throughout 20 years of operation is 2.39 kg/day or 100 g/GWh(e) which is a good agreement with other recent research. Problematic effects of neutron energy spectrum hardening during MSBR operation should be taken into account for neutronics, multi-physics, and fuel cycle performance analysis. Molten salt ; Breeder (animal) ; Thorium ; Breeder reactor ; Thorium fuel cycle ; Nuclear engineering ; Molten salt reactor ; Environmental science ; Fuel cycle ; Waste management ; Spent nuclear fuel ; Process engineering ; Engineering ; Materials science ; Uranium ; Metallurgy ; Blanket Nuclear Materials and Properties ; Graphite, nuclear technology, radiation studies ; Molten salt chemistry and electrochemical processes