jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zahra Salehi | Iman Gholaminezhad
Source: International journal of energy and environmental engineering (article, 2018-03-19)
Field: Materials Science — Materials Chemistry

Multi-objective modeling, uncertainty analysis, and optimization of reversible solid oxide cells Reversible solid oxide cells can provide efficient and cost-effective scheme for electrical-energy storage applications. However, this technology faces many challenges from material development to system-level operational parameters , which should be tackle for practical purposes. Accordingly, this study focuses on developing novel robust artificial intelligence-based black-box models to optimize operational variables of the system. A genetic-programming algorithm is used for Pareto modeling of reversible solid oxide cells in a multi-objective fashion based on experimental input–output data. The robustness of the obtained optimal model evaluated using Monte Carlo simulations technique. An optimization study adopted to optimize the operating parameters, such as temperature and fuel composition using a differential evolution algorithm. The objective functions that have been considered for Pareto multi-objective modeling process are training error and model complexity. In addition, the discrepancy between maximum and minimum output voltage in the whole operation of the system is chosen as the optimization process objective function. The robustness of the optimal trade-off model is shown in terms of statistical indices for varied uncertainty levels from 1 to 10%. The optimized operational condition based on the suggested model reveals optimal intermediate temperature of 762 °C and fuel mixture of about 29% H2, 25% H2O, and 14% CO. Robustness (evolution) ; Multi-objective optimization ; Mathematical optimization ; Computer science ; Monte Carlo method ; Pareto principle ; Genetic algorithm ; Voltage ; Optimization problem ; Algorithm ; Engineering ; Mathematics ; Chemistry Advancements in Solid Oxide Fuel Cells ; Catalytic Processes in Materials Science ; Chemical Looping and Thermochemical Processes
Authors: Anita Rácz | Marietta Fodor | Károly Héberger
Source: Analytical Methods (article, 2018-01-01)
Field: Chemistry — Analytical Chemistry

Development and comparison of regression models for the determination of quality parameters in margarine spread samples using NIR spectroscopy More than a hundred margarine samples and their FT-NIR spectra were used to develop regression models, and to compare them with sum of ranking differences and ANOVA. Ranking (information retrieval) ; Regression analysis ; Linear regression ; Statistics ; Regression ; Quality (philosophy) ; Mathematics ; Analytical Chemistry (journal) ; Chromatography ; Chemistry ; Computer science ; Artificial intelligence ; Physics Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research ; Meat and Animal Product Quality
Authors: S. Shivashankar | R. Madhuri
Source: International Journal of Computer Applications (article, 2018-03-20)
Field: Chemistry — Organic Chemistry

Automatic Wood Classification using a Novel Color Texture Features A variety of texture classification approaches have been reported in the literature but many of them are focused on gray-scale textures. The aim of this work is to develop a novel color texture features by constructing a histogram based on the combined intensity and color channel information to effectively classify color texture images. Five features are computed from the histogram bin values to reduce the computational complexity. Experiments are conducted on a set of 164 color texture images from VisTex database. The K-Nearest Neighbor (K-NN) classification method is used as a classifier. The classification results are encouraging to use the proposed scheme with reduction in features. Further the proposed scheme is used in automatic wood classification to show the usefulness of the proposed scheme in industrial applications. Computer science ; Texture (cosmology) ; Artificial intelligence ; Pattern recognition (psychology) ; Computer vision ; Image (mathematics) Wood and Agarwood Research ; Industrial Vision Systems and Defect Detection ; Remote Sensing and LiDAR Applications
Authors: Igor Ostanin | Petr Zhilyaev | V. Petrov | Traian Dumitrică | Sebastian Eibl | Ulrich Ruede | Vitaly A. Kuzkin
Source: Letters on Materials (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

Toward large scale modeling of carbon nanotube systems with the mesoscopic distinct element method We introduce a new scalable and efficient implementation of the mesoscopic distinct element method for massively parallel numerical simulations of carbon nanotube systems. Carbon nanotubes are represented as chains of rigid bodies, linked by elastic bonds and dispersive van der Waals (vdW) forces. The Enhanced Vector Model formalism is employed here to capture the elastic deformation of nanotubes. Dispersive interactions between the neighboring nanotubes are described with the coarse-grained vdW potential. Time integration is performed using a velocity Verlet integration scheme with tunable damping in order to describe the energy dissipation to the implicit degrees of freedom. Due to the scalable Message Passing Interface (MPI) parallelization, enabled by rigid particle dynamics module (PE) of the waLBerla multiphysics framework, our method is capable of modeling large assemblies of carbon nanotubes. This advance enables us to move closer to the length and time scales required to extract representative mechanics of carbon nanotube materials. The promising scalability of the new implementation is probed in two examples of self-assembly of ultra-thin carbon nanotube films and carbon nanotube buckypapers, where formation of hierarchical networks of carbon nanotube bundles, storing both elastic and vdW adhesion energy is being observed. The relaxation of one cubic micrometer of buckypaper illustrates the code scalability. Carbon nanotube ; Materials science ; Mesoscopic physics ; Buckypaper ; van der Waals force ; Multiphysics ; Nanotechnology ; Nanotube ; Molecular dynamics ; Dissipative particle dynamics ; Carbon nanotube actuators ; Continuum mechanics ; Finite element method ; Composite material ; Mechanical properties of carbon nanotubes ; Mechanics ; Computational chemistry ; Physics ; Condensed matter physics ; Molecule ; Thermodynamics ; Chemistry Carbon Nanotubes in Composites ; Graphene research and applications ; Smart Materials for Construction
Authors: Chunyan Liang | Xuezhen Feng | Jin‐Gang Yu | Xinyu Jiang
Source: Desalination and Water Treatment (article, 2018-11-01)
Field: Materials Science — Materials Chemistry

Graphene oxide/Mg-Fe layered double hydroxide composites for highly efficient removal of heavy metal ions from aqueous solution Adsorption ; Hydroxide ; Aqueous solution ; Langmuir adsorption model ; Oxide ; Metal ions in aqueous solution ; Materials science ; Graphene ; Endothermic process ; Inorganic chemistry ; Scanning electron microscope ; Fourier transform infrared spectroscopy ; Metal ; Chemical engineering ; Composite material ; Chemistry ; Metallurgy ; Physical chemistry ; Nanotechnology Layered Double Hydroxides Synthesis and Applications
Authors: Jinxin Guo | Jialing Jian | Meng Wang | Yasuo Tomita | Lin Cao | Dayong Wang | Xinping Zhang
Source: Nanophotonics (article, 2018-06-01)
Field: Chemistry — Organic Chemistry

Ag nanoparticle‐enhanced alkyl radical generation in photopolymerization for holographic recording Abstract We report a new Ag nanoparticle‐dispersed polymer nanocomposite for volume holographic recording through acrylic photopolymerization. The initial grating buildup dynamics at the inhibition stage are measured at various Ag nanoparticle concentrations. The refractive index modulation amplitude as large as 0.0069 at 633 nm is seen at the optimum Ag nanoparticle concentration of 1 wt.% with respect to the monomer. Electron paramagnetic resonance measurements show that Ag nanoparticles influence both the generation of alkyl radicals and the scavenging of oxygen in free radical photopolymerization. This mechanism intrinsically determines the molecular weight of polymer being formed and, thereby, affects the refractive index modulation amplitude of the formed grating as a function of Ag nanoparticle concentrations. Moreover, we confirm that two‐beam holographic exposure leads to a periodic assembly of dispersed Ag nanoparticles using a dark‐field microscopy. Our results suggest a simple way to control the photopolymerization and, therefore, to tailor polymers for practical uses. Photopolymer ; Materials science ; Nanoparticle ; Polymer ; Refractive index ; Nanocomposite ; Holographic grating ; Holography ; Silver nanoparticle ; Photochemistry ; Grating ; Monomer ; Chemical engineering ; Diffraction grating ; Nanotechnology ; Optoelectronics ; Optics ; Chemistry ; Composite material Photopolymerization techniques and applications ; Photorefractive and Nonlinear Optics ; Photonic Crystals and Applications
Authors: Syed A. Haque | Socrates Jose P. Cañete
Source: Journal of Analytical Science & Technology (article, 2018-01-17)
Field: Chemistry — Spectroscopy

HPLC-CUPRAC post-column derivatization method for the determination of antioxidants: a performance comparison between porous silica and core-shell column packing The CUPRAC post-column derivatization method can be improved using core-shell columns and suitable for quantifying antioxidants, exemplified by catechin and EGCG, in tea samples. Derivatization ; Chromatography ; Reagent ; High-performance liquid chromatography ; Chemistry ; Matrix (chemical analysis) ; Porosity ; Catechin ; Epigallocatechin gallate ; Van Deemter equation ; Silica gel ; Shell (structure) ; Polyphenol ; Column (typography) ; Materials science ; Organic chemistry ; Antioxidant ; Computer science Analytical Chemistry and Chromatography ; Tea Polyphenols and Effects ; Phytochemicals and Antioxidant Activities
Authors: S. Alam | Noor Rehman | Noor Ul Amin | Luqman Ali Shah | Inamullah Mian | Hidayat Ullah
Source: Bulletin of the Chemical Society of Ethiopia (article, 2018-01-19)
Field: Chemistry — Spectroscopy

Removal of basic green 5 by carbonaceous adsorbent: Adsorption kinetics The Eucalyptus lenceolata wood was collected from Malakand division, Khyber Pakhtunkhwa Pakistan. Chemical activation of sample was conducted for surface efficiency. Batch studies were performed to address various experimental parameters like, contact time, temperature and adsorbent dosage for the removal of dye. For elemental analysis, surface morphology and for identification of different functional groups, energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) techniques were applied, respectively. Removal of dye (Basic Green 5) was studied on raw and activated samples by kinetics adsorption at different temperature. BET adsorption isotherm was used to characterize the surface area of the sample. Under the conditions investigated, a higher carbonization temperature promoted development of porous structures. Intraparticle diffusion, Elovich and Bhangam models were used for adsorption kinetics studies. From adsorption kinetic data thermodynamic parameters like ΔH≠, ΔS≠ and ΔE≠ were determined. The results show that the adsorption is spontaneous process. The endothermic nature of adsorptive process is due to the positive value of enthalpy. The negative entropy shows that acids molecules on the surface of adsorbent take an oriented position. The results shows that all the models were best fitted for these data of adsorption. KEY WORDS: Activated carbon, Adsorption, SEM, EDS, FTIR, Surface area Bull. Chem. Soc. Ethiop. 2017, 31(3), 411-422. DOI: http://dx.doi.org/10.4314/bcse.v31i3.5 Adsorption ; Chemistry ; Endothermic process ; Fourier transform infrared spectroscopy ; Activated carbon ; Enthalpy ; Kinetics ; Carbonization ; Chemical engineering ; Organic chemistry ; Thermodynamics Adsorption, diffusion, and thermodynamic properties of materials ; Adsorption and biosorption for pollutant removal
Authors: Liang Yuan | Meng Li | Tinglian Yuan | Yimin Fang | Wei Wang
Source: Chemical Science (article, 2018-01-01)
Field: Chemistry — Electrochemistry

<i>In operando</i> imaging of self-catalyzed formaldehyde burst in methanol oxidation reactions under open circuit conditions We employ a surface plasmon resonance imaging (SPRi) technique to monitor the <i>in operando</i> process of formaldehyde (HCHO) production during methanol oxidation with high spatial and temporal resolutions. While common wisdom suggests HCHO is generated as an intermediate during continuous electron transfer towards CO<sub>2</sub>, we find that the majority of HCHO is produced <i>via</i> self-catalyzed chemical and electrochemical reactions under open-circuit conditions, which lead to an unprecedented HCHO burst immediately after withdrawal of external potential. Because open-circuit conditions better represent the operating environments of practical direct methanol fuel cells (DMFCs), this work uncovers a hidden pathway of HCHO accumulation by adopting a quantitative and <i>in operando</i> SPRi technique for the first time. These theoretical and technical advances are anticipated to help the fundamental understanding of the comprehensive mechanism of methanol oxidation with implications for improving the performance of DMFCs. Methanol ; Formaldehyde ; Catalysis ; Open-circuit voltage ; Photochemistry ; Chemistry ; Organic chemistry ; Physics ; Voltage Electrochemical Analysis and Applications ; Spectroscopy and Quantum Chemical Studies ; Advanced Memory and Neural Computing
Authors: Moumita Maiti | Michael Schmiedeberg
Source: Scientific Reports (article, 2018-01-24)
Field: Materials Science — Materials Chemistry

Ergodicity breaking transition in a glassy soft sphere system at small but non-zero temperatures While the glass transition at non-zero temperature seems to be hard to access for experimental, theoretical, or simulation studies, jamming at zero temperature has been studied in great detail. Motivated by the exploration of the energy landscape that has been successfully used to investigate athermal jamming, we introduce a new method that includes the possibility of the thermally excited crossing of energy barriers. We then determine whether the ground state configurations of a soft sphere system are accessible or not and as a consequence whether the system is ergodic or effectively non-ergodic. Interestingly, we find an transition where the system becomes effectively non-ergodic if the density is increased. The transition density in the limit of small but non-zero temperatures is independent of temperature and below the transition density of athermal jamming. This confirms recent computer simulation studies where athermal jamming occurs deep inside the glass phase. In addition, we show that the ergodicity breaking transition is in the universality class of directed percolation. Therefore, our approach not only makes the transition from an ergodic to an effectively non-ergodic systems easily accessible and helps to reveal its universality class but also shows that it is fundamentally different from athermal jamming. Ergodicity ; Jamming ; Ergodic theory ; Universality (dynamical systems) ; Excited state ; Ground state ; Limit (mathematics) ; Renormalization group Material Dynamics and Properties ; Theoretical and Computational Physics ; Random lasers and scattering media
Authors: B. Gurrutxaga-Lerma | J. Verschueren
Source: Physical review. B./Physical review. B (article, 2018-10-11)
Field: Materials Science — Materials Chemistry

Elastic models of dislocations based on atomistic Kanzaki forces This paper studies the relationship between the atomistic representation of crystalline dislocations as Kanzaki forces and the continuum representation of dislocations as Burridge-Knopoff (BK) force distributions. We first derive a complete theory of the BK force representation of dislocations in an anisotropic linear elastic continuum, showcasing a number of fundamental features found when dislocations are represented as distributions of body forces in defect-free continuum media. We then build, within the harmonic approximation, the Kanzaki force representation of dislocations in atomistic lattice models. We rigorously show that in the long-wave limit, the Kanzaki force representation converges to the continuum BK representation. We therefore justify employing the Kanzaki forces as source terms in continuum theories of dislocations. We do this by establishing a methodology to compute the Kanzaki forces of dislocations via the force constant matrix of the material's perfect lattice. We use it to study a model of a screw dislocation in bcc tungsten, where we show the existence of two distinct Kanzaki force terms: the slip Kanzaki forces, which we show directly correspond with the BK forces implied by a Volterra dislocation; and the core Kanzaki forces, which are computed from the relaxed dislocation structure, and serve to model all core effects not captured by the Volterra dislocation. We build a multipolar field expansion of both the core and the slip Kanzaki forces, showing that the dislocation core is agreeable to correction via the multipolar field expansion of the core Kanzaki forces. Physics ; Materials science ; Classical mechanics ; Condensed matter physics Microstructure and mechanical properties ; Electromagnetic Effects on Materials ; Force Microscopy Techniques and Applications
Authors: Andrea Carpinteri | Vittorio Di Cocco | Giovanni Fortese | Francesco Iacoviello | Stefano Natali | Camilla Ronchei | Daniela Scorza | Sabrina Vantadori | Andrea Zanichelli
Source: Acta Mechanica et Automatica (article, 2018-06-01)
Field: Materials Science — Materials Chemistry

Mechanical Behaviour and Phase Transition Mechanisms of a Shape Memory Alloy by Means of a Novel Analytical Model Abstract The aim of the present paper is to examine both the fatigue behaviour and the phase transition mechanisms of an equiatomic pseudo-elastic NiTi Shape Memory Alloy through cyclic tests (up to 100 loading cycles). More precisely, miniaturised dog-bone specimens are tested by using a customised testing machine and the contents of both austenite and martensite phase are experimentally measured by means of X-Ray diffraction (XRD) analyses. On the basis of such experimental results in terms of martensite content, an analytical model is here formulated to correlate the stress-strain relationship to the phase transition mechanisms. Finally, a validation of the present model by means of experimental data pertaining the stress-strain relationship is performed. Shape-memory alloy ; Materials science ; Martensite ; Nickel titanium ; Austenite ; Alloy ; Phase transition ; Stress (linguistics) ; Experimental data ; Phase (matter) ; Diffraction ; Structural engineering ; Metallurgy ; Composite material ; Thermodynamics ; Microstructure ; Engineering ; Mathematics ; Optics ; Physics Shape Memory Alloy Transformations ; Titanium Alloys Microstructure and Properties
Authors: Monika Gawrońska‐Grzywacz | Łukasz Popiołek | Dorota Natorska‐Chomicka | Iwona Piątkowska‐Chmiel | Magdalena Izdebska | Mariola Herbet | Magdalena Iwan | Agnieszka Korga-Plewko | Jarosław Dudka | Monika Wujec
Source: Oncology Reports (article, 2018-10-16)
Field: Chemistry — Organic Chemistry

Novel 2,3‑disubstituted 1,3‑thiazolidin‑4‑one derivatives as potential antitumor agents in renal cell adenocarcinoma Cancer represents one of the main causes of mortality in developed countries. In particular, the overall survival of patients with renal cell carcinoma (RCC) remains poor and the available cytostatic agents are insufficient. Therefore, there is an urgent requirement to identify more effective and safer anticancer drugs. Recently, the evaluation of antitumor activity appeared to be promising for thiazolidinone derivatives. The present study presents the synthesis and the cytotoxicity assays of 1,3‑thiazolidin‑4‑ones. The newly synthesized substances were screened in vitro against selected cancer human renal cell adenocarcinoma cells (769‑P), human hepatoblastoma‑derived cells (HepG2) and normal green monkey kidney cells (GMK) as a reference cell line. N‑[2‑(4‑methylphenyl)‑4‑oxo‑1,3‑thiazolidin‑3‑yl]acetamide and N‑[2‑(4‑methylphenyl)‑4‑oxo‑1,3‑thiazolidin‑3‑yl]benzamide displayed significant antiproliferative activity towards 769‑P. To elucidate the mechanisms of the cytotoxic actions, additional studies on the cell cycle and apoptosis were performed. The aforementioned compounds were responsible for G1 cell cycle arrest and the decrease in cell distribution in the G2 phase in a dose‑dependent manner, which prevents mitotic divisions of the 769‑P cells. In addition, these novel 2,3‑disubstituted 1,3‑thiazolidin‑4‑ones slightly induced apoptosis in 769‑P in a dose‑dependent manner. It was hypothesized that the 4‑methylphenyl group at position 2 of the thiazolidin‑4‑one scaffold may be regarded as a promising moiety for further development of this group of compounds. Therefore, benzamide moiety appeared to be crucial for triggering cells to apoptotic cell death. Cell cycle ; Apoptosis ; Cytotoxicity ; Oncogene ; Cytotoxic T cell ; Benzamide ; Cell growth ; Cancer cell ; Cancer research ; Cell ; Cell culture ; Moiety ; Cell cycle checkpoint ; Chemistry ; Biology ; Cancer ; Pharmacology ; In vitro ; Stereochemistry ; Biochemistry ; Medicine ; Internal medicine Synthesis and biological activity ; Cancer Mechanisms and Therapy ; Cancer, Lipids, and Metabolism
Authors: Kamal Kumar | Herbert Waldmann
Source: Israel Journal of Chemistry (article, 2018-10-18)
Field: Chemistry — Organic Chemistry

Nature Inspired Small Molecules for Chemical Biology Abstract Chemical biology and drug discovery are instrumental sciences to address unmet medical needs and to gain a deeper understanding of normal and disease state biology in mammalian systems. Unlike most genetic tools, the small molecule modulation of biology is reversible, controllable in space, time and quantity, avoids the removal of gene products from cellular systems and thus enables perturbation of biology in its native state. Natural products, their derivatives as well as small molecules based on the core‐scaffolds of natural products including natural product fragments allow targeting unique, biologically relevant fractions of chemical space that may deliver quality tool compounds. In this essay, we discuss various synthesis approaches inspired by natural products to deliver biologically active small molecules. We argue and provide evidence that inspiration by natural product structure remains a powerful guiding principle for the development of novel approaches to the study biology by means of novel bioactive small molecules. Chemical biology ; Chemical space ; Small molecule ; Natural product ; Drug discovery ; Chemistry ; Synthetic biology ; Computational biology ; Systems biology ; Nanotechnology ; Biochemical engineering ; Biology ; Biochemistry Click Chemistry and Applications ; Ubiquitin and proteasome pathways ; Chemical Synthesis and Analysis