jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Walter Díaz | Carlos Toro | Eduardo Balladares | Víctor Parra | Pablo Coelho | Gonzalo Reyes | Roberto Parra
Source: Metals (article, 2019-09-19)
Field: Chemistry — Analytical Chemistry

Spectral Characterization of Copper and Iron Sulfide Combustion: A Multivariate Data Analysis Approach for Mineral Identification on the Blend The pyrometallurgical processes for primary copper production have only off-line and time-demanding analytical techniques to characterize the in and out streams of the smelting and converting steps. Since these processes are highly exothermic, relevant process information could potentially be obtained from the visible and near-infrared radiation emitted to the environment. In this work, we apply spectral sensing and multivariate data analysis methodologies to identify and classify copper and iron sulfide minerals present in the blend from spectra measured during their combustion in a laboratory drop-tube setup, in which chemical reactions that take place in flash smelting furnaces can be reproduced. Controlled combustion experiments were conducted with two industrial concentrates and with high-grade mineral species as well, with a focus on pyrite and chalcopyrite. Exploratory analysis by means of Principal Component Analysis (PCA) applied on the spectral data depicted high correlation features among species with similar elemental compositions. Classification algorithms were tested on the spectral data, and a classification accuracy of 95.3% with a support vector machine (SVM) algorithm with a Gaussian kernel was achieved. The results obtained by the described procedures are shown to be very promising as a first step in the development of a predictive and analytical tool in search of fitting the current need for real-time control of pyrometallurgical processes. Flash smelting ; Pyrite ; Principal component analysis ; Chalcopyrite ; Iron sulfide ; Support vector machine ; Sulfide ; Combustion ; Process engineering ; Bornite ; Computer science ; Smelting ; Chemistry ; Copper ; Mineralogy ; Materials science ; Sulfur ; Artificial intelligence ; Metallurgy ; Engineering Spectroscopy and Chemometric Analyses ; Mineral Processing and Grinding ; Metal Extraction and Bioleaching
Authors: Abdolhossein Hemmati‐Sarapardeh | Sassan Hajirezaie | Mohamad Reza Soltanian | Amir Mosavi | Shahab Shamshirband
Source: Preprints.org (preprint, 2019-05-22)
Field: Chemistry — Analytical Chemistry

Modeling Natural Gas Compressibility Factor Using a Hybrid Group Method of Data Handling A Natural gas is increasingly being sought after as a vital source of energy, given that its production is very cheap and does not cause the same environmental harms that other resources, such as coal combustion, do. Understanding and characterizing the behavior of natural gas is essential in hydrocarbon reservoir engineering, natural gas transport, and process. Natural gas compressibility factor, as a critical parameter, defines the compression and expansion characteristics of natural gas under different conditions. In this study, a simple second-order polynomial model based on the group method of data handling (GMDH) is presented to determine the compressibility factor of different natural gases at different conditions, using corresponding state principles. The accuracy of the model evaluated through graphical and statistical analyses. The results show that the model is capable of predicting natural gas compressibility with an average absolute error of only 2.88%, a root means square of 0.03, and a regression coefficient of 0.92. The performance of the developed model compared to widely known, previously published equations of state (EOSs) and correlations, and the precision of the results demonstrates its superiority over all other correlations and EOSs. Compressibility factor ; Natural gas ; Compressibility ; Equation of state ; Coal ; Polynomial ; Coefficient of determination ; Petroleum engineering ; Thermodynamics ; Mathematics ; Statistics ; Engineering ; Physics ; Mathematical analysis ; Waste management Petroleum Processing and Analysis ; Phase Equilibria and Thermodynamics ; Atmospheric and Environmental Gas Dynamics
Authors: Francesca Curà | Raffaella Sesana | Xiao-Chong Zhang | Fabrizio Scarpa | Wen Lu | Hua-Xin Peng
Source: Advanced Engineering Materials (article, 2019-09-13)
Field: Materials Science — Polymers and Plastics

Stiffness, Energy Dissipation, and Hyperelasticity in Hierarchical Multilayer Composite Nanocoated Open‐Cell Polyurethane Foams The manufacturing, testing, and modeling of a class of open‐cell polyurethane (PU) foams doped with multiwalled carbon nanotubes (MWCNTs) and nano‐PU dispersions (PUDs) and subjected to quasistatic cycling compressive loading at large deformations are described. The doped nanoink foams are produced using a multiple‐step dip coating technique that makes the development of nano‐based porous materials by postprocessing existing off‐the‐shelf open‐cell foams possible. Tests are conducted up to 18.5% of compressive strain to identify loading/unloading moduli and energy absorbed after five cycles of stabilization. Hyperelastic Ogden models also considering the Mullins effect for cyclic loading are used to identify the constitutive parameters for these foams. The results show that the use of MWCNT layers provides an effective increase in the stiffness and energy absorbed compared with pristine and nano‐PUDs‐treated foams. The volume average energy absorbed after the stabilization cycles is increased by 200% compared with the pristine foam when the MWCNT layers are used. The parameters of the constitutive models extracted from the tests show that these nanoink foams are modeled following state‐of‐the‐art hyperelastic representations. Materials science ; Hyperelastic material ; Composite material ; Polyurethane ; Quasistatic process ; Composite number ; Quasistatic loading ; Stiffness ; Finite element method ; Structural engineering Polymer composites and self-healing ; Cellular and Composite Structures ; Elasticity and Material Modeling
Authors: Konrad Pietruk | Marta Piątkowska | Małgorzata Olejnik
Source: Journal of Veterinary Research (article, 2019-07-22)
Field: Chemistry — Analytical Chemistry

Electrochemical reduction of azo dyes mimicking their biotransformation to more toxic products Electrochemistry-mass spectrometry was successfully applied to azo dyes. This approach may be used to mimic the metabolism of azo dyes, and therefore predict products of biotransformation. Chemistry ; Biotransformation ; Aniline ; Formic acid ; Electrochemistry ; Acetonitrile ; Aniline Compounds ; Organic chemistry ; Nuclear chemistry ; Electrode Dye analysis and toxicity ; Enzyme-mediated dye degradation ; Microbial Metabolism and Applications
Authors: Christoph B. Messner | Vadim Demichev | Nic Bloomfield | Matthew White | Marco Kreidl | Gordana Ivosev | Fras Wasim | Aleksej Zelezniak | Kathryn S. Lilley | Stephen Tate | Markus Ralser
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2019-05-31)
Field: Chemistry — Spectroscopy

Scanning SWATH acquisition enables high-throughput proteomics with chromatographic gradients as fast as 30 seconds Abstract Bridging genotype to phenotype, the proteome has increasingly become of major importance to generate large, longitudinal sample series for data-driven biology and personalized medicine. Major improvements in laboratory automation, chromatography and software have increased the scale and precision of proteomics. So far missing are however mass spectrometric acquisition techniques that could deal with very fast chromatographic gradients. Here we present scanning SWATH, a data-independent acquisition (DIA) method, in which the DIA-typical stepwise windowed acquisition is replaced by a continuous movement of the precursor isolation window. Scanning SWATH accelerates the duty cycles to a few hundreds of milliseconds, and enables precursor mass assignment to the MS2 fragment traces for improving true positive precursor identification in fast proteome experiments. In combination with 800 µL/min high-flow chromatography, we report the quantification of 270 precursors per second, increasing the precursor identifications by 70% or more compared to previous methods. Scanning SWATH quantified 1,410 Human protein groups in conjunction with chromatographic gradients as fast as 30 seconds, 2,250 with 60-second gradients, and 4,586 in conjunction with 5-minute gradients. At high quantitative precision, our method hence increases the proteomic throughput to hundreds of samples per day per mass spectrometer. Scanning SWATH hence enables a broad range of new proteomic applications that depend on large numbers of cheap yet quantification precise proteomes. Mass spectrometry ; Proteome ; Proteomics ; Chromatography ; Laboratory automation ; Data acquisition ; Throughput ; Computer science ; Longitudinal sample ; Automation ; Biological system ; Chemistry ; Bioinformatics ; Biology Advanced Proteomics Techniques and Applications ; Mass Spectrometry Techniques and Applications ; Metabolomics and Mass Spectrometry Studies
Authors: Yunfeng Liu | Zhengsong Qiu | Hanyi Zhong | Zhen Nie | Jia Li | Weian Huang | Xin Zhao
Source: Materials (article, 2019-08-21)
Field: Chemistry — Analytical Chemistry

Bitumen Recovery from Crude Bitumen Samples from Halfaya Oilfield by Single and Composite Solvents—Process, Parameters, and Mechanism Since 2007, heterogeneous, high-viscosity active bituminous formations have often occurred during the drilling process in Yadavaran oilfield (Iran), Halfaya oilfield (Iraq), and tar sands (Canada). The formation of bitumen exhibits plastic and creep properties, and its adhesion is strong, so drilling accidents are easily caused, such as adhering vibrating screen, drill pipe sticking, lost circulation, and even well abandonment. These complex problems cause huge economic losses. Solvents used to dissolve bitumen are a feasible technology to remove bitumen effectively. In order to solve this problem, we used crude bitumen samples from Halfaya oilfield to study the relation between the bitumen component and different solvents. In this study, the temperature, crude bitumen sample to solvent ratio, stirring rate, stirring time, and ultrasound time on bitumen recovery by toluene were investigated by a single factor experiment. The optimum process parameter for bitumen recovery was obtained. Toluene, n-heptane, tetrahydrofuran, cyclohexane, cyclopentane, ethyl acetate, and n-pentane were chosen as the solvents for single solvent extraction and composite solvent extraction. The bitumen recovery increased significantly with the use of a composite solvent compared to a single solvent. The composite solvent ratio was 1:1. The highest bitumen recovery was 98.9 wt% by toluene/cyclohexane composite solvent. The SARA (saturates, aromatics, resins, and asphaltenes) components of the bitumen were analyzed. The toluene showed the highest asphaltene content, while the n-alkanes showed the lowest asphaltene content. The higher the asphaltene content, the higher the bitumen recovery. The composite solvent obtained the highest asphaltene content and bitumen recovery. The viscosity of bitumen extraction by different solvents was measured. The lower the bitumen viscosity, the higher the bitumen recovery. The element analysis indicated the solvent's ability to extract bitumen colloids with the C/H ratio. This study provides a reliable theoretical basis for the subsequent adoption of effective anti-bitumen polluted drilling fluid additives. Asphalt ; Composite number ; Mechanism (biology) ; Process (computing) ; Petroleum engineering ; Materials science ; Crude oil ; Composite material ; Process engineering ; Geology ; Engineering ; Computer science Petroleum Processing and Analysis ; Enhanced Oil Recovery Techniques ; Hydrocarbon exploration and reservoir analysis
Authors: Esra Taştan Özkan | Binnaz Kaplangiray
Source: Journal of Textile Engineering & Fashion Technology (article, 2019-02-22)
Field: Materials Science — Polymers and Plastics

Investigating thermophysiological comfort properties of polyester knitted fabrics Sport clothes are mainly produced from polyester yarn because of good wicking behaviour and moisture transfer properties of this yarn. In this paper, thermophysiological comfort properties of ring staple polyester, textured polyester and special type of polyester knitted fabrics, which is described as good moisture management property yarn by producer, were investigated. For this reason, thermal resistance, thermal absorptivity, thermal conductivity, air permeability and moisture managent properties of fabrics were tested. The results showed that, textured polyester yarn knitted fabrics were showed the highest air permeability values than moisture management polyester in same yarn count and knit structure. Lower filament number fabrics shows higher thermal resistance values in same yarn count of fabrics. Moisture management polyester knitted fabric (Type 10) showed the highest top absorption and one way transport index value. Also moisture management polyester yarn knitted fabrics, except Type 7, were showed very good moisture management properties according to MMT grading scale. This is most probably cross-sectional shape of this fiber. Polyester ; Materials science ; Composite material Textile materials and evaluations ; Thermoregulation and physiological responses ; Ergonomics and Musculoskeletal Disorders
Authors: Christina Schindler | Eva Hollenbach | Thomas Mietzner | Klaus‐Jürgen Schleifer | Martin Zacharias
Source: Protein Science (article, 2019-04-04)
Field: Chemistry — Inorganic Chemistry

Free energy calculations elucidate substrate binding, gating mechanism, and tolerance‐promoting mutations in herbicide target 4‐hydroxyphenylpyruvate dioxygenase 4-Hydroxyphenylpyruvate dioxygenase (HPPD) catalyzes the second reaction in the tyrosine catabolism and is linked to the production of cofactors plastoquinone and tocopherol in plants. This important biological role has put HPPD in the focus of current herbicide design efforts including the development of herbicide-tolerant mutants. However, the molecular mechanisms of substrate binding and herbicide tolerance have yet to be elucidated. In this work, we performed molecular dynamics simulations and free energy calculations to characterize active site gating by the C-terminal helix H11 in HPPD. We compared gating equilibria in Arabidopsis thaliana (At) and Zea mays (Zm) wild-type proteins retrieving the experimentally observed preferred orientations from the simulations. We investigated the influence of substrate and product binding on the open-closed transition and discovered a ligand-mediated conformational switch in H11 that mediates rapid substrate access followed by active site closing and efficient product release through H11 opening. We further studied H11 gating in At mutant HPPD, and found large differences with correlation to experimentally measured herbicide tolerance. The computational findings were then used to design a new At mutant HPPD protein that showed increased tolerance to six commercially available HPPD inhibitors in biochemical in vitro experiments. Our results underline the importance of protein flexibility and conformational transitions in substrate recognition and enzyme inhibition by herbicides. Dioxygenase ; Gating ; Mutant ; Substrate (aquarium) ; Chemistry ; Biophysics ; Active site ; Biochemistry ; Stereochemistry ; Binding site ; Molecular dynamics ; Enzyme ; Biology ; Computational chemistry Metal-Catalyzed Oxygenation Mechanisms ; Photosynthetic Processes and Mechanisms ; Microbial Metabolic Engineering and Bioproduction
Authors: Mohamed E. Mahmoud | Asmaa Mohamed | Mohamed F. Amira | Seleim M. Seleim
Source: Journal of Chemical & Engineering Data (article, 2019-11-22)
Field: Chemistry — Inorganic Chemistry

Novel Nanostructured Metal–Organic Framework-Bonded Silica Amine and Polymer: Facile Synthesis, Kinetics, Isotherms, and Thermodynamics Evaluation for Adsorption of Yttrium(III) Ions Yttrium is a remarkable rare-earth element with multidiscipline applications, and it can be released into an aquatic system for its widespread industrial applications. The present work is devoted to evaluate the kinetics and isotherm models for adsorption of Y(III) ions by the action of a novel metal–organic framework (MOF) chemically bonded polymer with incorporated ion exchange and chelating characters. To assemble these MOFs, a number of synthetic procedures were designed and performed using microwave irradiation heating in only 12 min. (i) The selected MOFs were synthesized by the reaction of zinc acetate and glutaric to produce (ZnGA) in 3 min. (ii) Covalent bonding and coating of (ZnGA) with 3-aminopropyltrimethoxysilane were carried out to produce (ZnGA–Si–NH2) in 3 min. (iii) The polymeric compound was synthesized by coupling of p-chlorocresol with piperazine via formaldehyde to yield PC in 4 min. (iv) The final MOFs–polymer nanocomposite was synthesized by the functionalization of ZnGA–Si–NH2 with PC to assemble ZnGA–Si–NH–PC in 2 min. The impact of the polymer on stability of ZnGA–Si–NH–PC in aqueous solutions (pH 1–7) was confirmed and compared to the MOFs separately. Additionally, thermal stability and surface morphology of ZnGA–Si–NH–PC were also studied and evaluated. The metal sorption capacity values of Y(III) ions onto ZnGA–Si–NH–PC were optimized at pH 7 and established as 1175, 1925, and 4800 μmol g–1 using 0.025, 0.05, and 0.1 mol L–1 of Y(III), respectively. The interaction mechanisms for binding of Y(III) ions with ZnGA–Si–NH–PC were studied and evaluated by seven kinetics models and seven adsorption isotherm models, and the collected results confirmed that the adsorption process is well fitted with the pseudo-second-order and pore diffusion models. The collected data assured that the adsorption of Y(III) ions onto the ZnGA–Si–NH–PC nanocomposite is chemisorption (ΔH° = 42.44 kJ/mol) with the direct ion exchange mechanism of Y(III) ions with the surface hydrogen ions and coordinate bond formation mechanism with the nitrogen functional groups into the available pores of the ZnGA–Si–NH–PC nanocomposite. Adsorption ; Materials science ; Polymer ; Surface modification ; Yttrium ; Thermal stability ; Aqueous solution ; Metal ions in aqueous solution ; Ion exchange ; Metal-organic framework ; Inorganic chemistry ; Chemical engineering ; Polymer chemistry ; Metal ; Nuclear chemistry ; Chemistry ; Physical chemistry ; Ion ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Radioactive element chemistry and processing ; Chemical Synthesis and Characterization
Authors: I. Santamarı́a-Holek | S. I. Hernández | C. García-Alcántara | Aldo Ledesma–Durán
Source: Catalysts (article, 2019-03-19)
Field: Chemistry — Inorganic Chemistry

Review on the Macro-Transport Processes Theory for Irregular Pores able to Perform Catalytic Reactions We review and generalize a recent theoretical framework that provides a sound physicochemical basis to describe how volume and surface diffusion are affected by adsorption and desorption processes, as well as by catalytic conversion within the space defined by the irregular geometry of the pores in a material. The theory is based on two single-dimensional mass conservation equations for irregular domains deduced for the volumetric (bulk) and surface mass concentrations. It offers a powerful tool for analyzing and modeling mass transport across porous media like zeolites or artificially build materials, since it establishes how the microscopic quantities that refer to the internal details of the geometry, the flow and the interactions within the irregular pore can be translated into macroscopic variables that are currently measured in experiments. The use of the theory in mass uptake experiments is explained in terms of breakthrough curves and effective mass diffusion coefficients which are explicitly related to the internal geometry of the pores. Mass transport ; Porous medium ; Diffusion ; Surface (topology) ; Adsorption ; Mass transfer ; Porosity ; Materials science ; Conservation of mass ; Chemistry ; Mechanics ; Thermodynamics ; Physics ; Geometry ; Physical chemistry ; Mathematics ; Engineering physics ; Composite material Zeolite Catalysis and Synthesis ; Nanopore and Nanochannel Transport Studies ; Enhanced Oil Recovery Techniques
Authors: Ewa Skwarek | W. Janusz
Source: Adsorption (article, 2019-01-04)
Field: Chemistry — Inorganic Chemistry

Adsorption of Ba2+ ions at the hydroxyapatite/NaCl solution interface The study of the kinetics of barium adsorption at the hydroxyapatite/electrolyte interface using the radioactive isotope 133Ba2+ was carried out. The course of adsorption kinetics indicates that at the beginning adsorption proceeds quickly and then slowly. Such adsorption kinetics is best described by the multiexpotential equation. The adsorption of Ba2+ ions at the hydroxyapatite/ electrolyte interface proceeds via their adsorption of ions on the surface groups with the release of proton and the exchange of Ca ions from the crystal lattice. The adsorption process has an insignificant effect on the crystal lattice parameters and crystallinity degree but due to the decrease of zeta potential leads to particles aggregation. Adsorption ; Crystallinity ; Electrolyte ; Ion ; Zeta potential ; Kinetics ; Chemistry ; Inorganic chemistry ; Barium ; Materials science ; Chemical engineering ; Physical chemistry ; Crystallography ; Nanotechnology ; Organic chemistry Radioactive element chemistry and processing ; Chemical Synthesis and Characterization ; Bone Tissue Engineering Materials
Authors: Alexe Bojovschi | Tuan Vu Quoc | Huy Nguyen Trung | Dung Trinh Quang | Tu C. Le
Source: Applied Sciences (article, 2019-02-27)
Field: Materials Science — Materials Chemistry

Environmental Effects on HV Dielectric Materials and Related Sensing Technologies The increase in recent power failures, with negative impacts on humans and the economy, has been largely attributed to environmental effects and the aging of the power network. These have been accelerated in the last years due to two main factors: an increased load on the power network and material degradation owing to the presence of environmental pollutants. These factors together with specific weather conditions create the incipient conditions for power network degradation. In this paper, a review of the influence of environmental factors on high-voltage (HV) materials and components is provided. Sensing and artificial intelligence (AI) technologies developed to prevent the failure of the material structure and HV components are also reported. Power network ; Environmental science ; Degradation (telecommunications) ; Power (physics) ; Materials science ; Engineering ; Electrical engineering ; Electric power system High voltage insulation and dielectric phenomena ; Power Transformer Diagnostics and Insulation ; Electrical Fault Detection and Protection