jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zahir Razzaz | Denis Rodrigue
Source: Materials (article, 2018-11-17)
Field: Materials Science — Polymers and Plastics

Hollow Fiber Porous Nanocomposite Membranes Produced via Continuous Extrusion: Morphology and Gas Transport Properties In this work, hollow fiber porous nanocomposite membranes were successfully prepared by the incorporation of a porous nanoparticle (zeolite 5A) into a blend of linear low-density polyethylene (LLDPE)/low-density polyethylene (LDPE) combined with azodicarbonamide as a chemical blowing agent (CBA). Processing was performed via continuous extrusion using a twin-screw extruder coupled with a calendaring system. The process was firstly optimized in terms of extrusion and post-extrusion conditions, as well as formulation to obtain a good cellular structure (uniform cell size distribution and high cell density). Scanning electron microscopy (SEM) was used to determine the cellular structure as well as nanoparticle dispersion. Then, the samples were characterized in terms of mechanical and thermal stability via tensile tests and thermogravimetric analysis (TGA), as well as differential scanning calorimetry (DSC). The results showed that the zeolite nanoparticles were able to act as effective nucleating agents during the foaming process. However, the optimum nanoparticle content was strongly related to the foaming conditions. Finally, the membrane separation performances were investigated for different gases (CO₂, CH₄, N₂, O₂, and H₂) showing that the incorporation of porous zeolite significantly improved the gas transport properties of semi-crystalline polyolefin membranes due to lower cell wall thickness (controlling permeability) and improved separation properties (controlling selectivity). These results show that mixed matrix membranes (MMMs) can be cost-effective, easy to process, and efficient in terms of processing rate, especially for the petroleum industry where H₂/CH₄ and H₂/N₂ separation/purification are important for hydrogen recovery. Materials science ; Thermogravimetric analysis ; Differential scanning calorimetry ; Extrusion ; Chemical engineering ; Membrane ; Composite material ; Nanocomposite ; Low-density polyethylene ; Linear low-density polyethylene ; Polyolefin ; Blowing agent ; Porosity ; Polyethylene ; Chemistry Polymer Foaming and Composites ; Membrane Separation and Gas Transport ; Polymer crystallization and properties
Authors: Wojciech Skubida | Anna Niemczyk | Kun Zheng | Xin Liu | Konrad Świeczek
Source: Crystals (article, 2018-03-16)
Field: Materials Science — Materials Chemistry

Crystal Structure, Hydration, and Two-Fold/Single-Fold Diffusion Kinetics in Proton-Conducting Ba0.9La0.1Zr0.25Sn0.25In0.5O3−a Oxide In this work, hydration kinetics related to the incorporation of water into proton-conducting Ba0.9La0.1Zr0.25Sn0.25In0.5O3−a perovskite-type oxide are presented, with a recorded transition on temperature from a single-fold to a two-fold behavior. This can be correlated with an appearance of the electronic hole component of the conductivity at high temperatures. The collected electrical conductivity relaxation data allowed to calculate chemical diffusion coefficient D and surface exchange reaction coefficient k, as well as respective activation energies of their changes on temperature. Presented results are supplemented with a systematic characterization of the structural properties of materials synthesized at different temperatures, amount of incorporated water after hydration in different conditions, influence of water content on the crystal structure, as well as electrical conductivity in dry, H2O- and D2O-containing air, which enabled to evaluate proton (deuterium) conductivity. Conductivity ; Electrical resistivity and conductivity ; Proton ; Oxide ; Activation energy ; Chemistry ; Kinetics ; Deuterium ; Diffusion ; Crystal structure ; Analytical Chemistry (journal) ; Materials science ; Thermodynamics ; Crystallography ; Physical chemistry ; Chromatography ; Organic chemistry Advancements in Solid Oxide Fuel Cells ; Electronic and Structural Properties of Oxides ; Magnetic and transport properties of perovskites and related materials
Authors: Pravina B. Piste
Source: International Journal of Pharmaceutical Sciences and Drug Research (article, 2018-07-01)
Field: Chemistry — Organic Chemistry

NOVEL SYNTHESIS AND ANTIMICROBIAL ACTIVITIES OF THIAZINO-OXAZINE DERIVATIVES In the designing and synthesis of new heterocyclic compounds, containing two different pharmacophores, we have carried out new series of 3-(4-chlorophenyl)-4-methylidene-4,8-dihydro-2H,5H-1,3-thiazino[5,4-e]-1,3-oxazine-2,5,7(3H)-trione derivatives (5a-5k) in good yields from the cyclization of 5-[(1E)-N- (4-chlorophenyl) ethanimidoyl] -4-hydroxy- 2H-1,3- thiazine-2,6(3H)-dione derivatives (4a-4k) with triphosgene. All the synthesized compounds (5a-5k) were confirmed by spectral analysis. The synthesized compounds (5a-5k) were screened in vitro for their antibacterial activities against S. subtilis (gram positive) and E. coli. (gram negative) while antifungal activity against C. albicans by cup plate method. Some of the products of series were found to have quite good activities as compared to the standard drug streptomycin and flucanozole. Triphosgene ; Thiazine ; Pharmacophore ; Antimicrobial ; Streptomycin ; Candida albicans ; Gram ; Chemistry ; Corpus albicans ; Antibacterial activity ; Combinatorial chemistry ; Organic chemistry ; Stereochemistry ; Microbiology ; Bacteria ; Biology ; Antibiotics ; Biochemistry Synthesis and biological activity ; Synthesis and Characterization of Heterocyclic Compounds ; Phenothiazines and Benzothiazines Synthesis and Activities
Authors: Sandeep Dewal | Rachna Sharma | Radhey S. Gupta
Source: Asian Journal of Pharmaceutical and Clinical Research (review, 2018-08-07)
Field: Chemistry — Analytical Chemistry

A REVIEW ON ANTIFERTILITY ACTIVITY OF PLANTS OF CHAMBAL RIVERINE Indian sub-continent showing very high diversity in both ecological and geographical aspects. In India, medicinal plants are widely distributed in different climatic conditions and are abundant in a mountainous region or riverine area. In this review, are being discussed anti-fertility properties of India’s well-known Chambal riverine flora. This area is rich in many medicinal plants as Acyranthus aspera, Acacia catechu, Nelumbo nucifera, Nyctanthes arbortristis, Mimosa pudica, Adhatoda vasica, Calotropis gigantea, Pergularia daemia, Vicoa indica, etc. These plants possess potential antifertility activity and many phytoconstituents, responsible for antispermatogenic, anti-implantation, antiovulatory, antiandrogenic, and many more activities. Hence, this review comprises a brief study of some medicinal plants found in Chambal riverine and showing the comprehensive antifertility activity of those plants. Mimosa pudica ; Nelumbo nucifera ; Medicinal plants ; Flora (microbiology) ; Biology ; Traditional medicine ; Botany ; Medicine ; Lotus Chromatography in Natural Products ; Botanical Research and Chemistry
Authors: Rafaela A. L. Silva | Bruno J. C. Vieira | Marta A. Andrade | Isabel C. Santos | Sandra Rabaça | Elsa B. Lopes | Joana T. Coutinho | Laura C. J. Pereira | Manuel Almeida | Dulce Belo
Source: Molecules (article, 2018-02-14)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Gold and Nickel Extended Thiophenic-TTF Bisdithiolene Complexes Gold and nickel bisdithiolene complexes with methyl and <i>tert</i>-butyl substituted thiophenetetrathiafulavalenedithiolate ligands (α-mtdt and α-tbtdt) were prepared and characterized. These complexes were obtained, under anaerobic conditions, as tetrabutylammonium salts. The diamagnetic gold monoanion (<i>n</i>-Bu₄N)[Au(α-mtdt)₂] (<b>3</b>) and nickel dianionic species (<i>n</i>-Bu₄N)<sub>x</sub>[Ni(α-mtdt)₂] (x = 1,2) (<b>4</b>) were similar to the related non-substituted extended thiophenic-TTF (TTF = tetrathiafulvalene) bisdithiolenes. However the introduction of the large, bulky substituent <i>tert</i>-butyl, led to the formation of a Au (I) dinuclear complex, (<i>n</i>-Bu₄N)₂[Au₂(α-tbtdt)₂] (<b>5</b>). The neutral methyl substituted gold and nickel complexes were easily obtained through air or iodine exposure as polycrystalline or amorphous fine powder. [Au(α-mtdt)₂] (<b>6</b>) and [Ni(α-mtdt)₂] (<b>7</b>) polycrystalline samples display properties of a metallic system with a room temperature electrical conductivity of 0.32 S/cm and ≈4 S/cm and a thermoelectric power of ≈5 µV/K and ≈32 µV/K, respectively. While [Au(α-mtdt)₂] (<b>6</b>) presented a Pauli-like magnetic susceptibility typical of conducting systems, in [Ni(α-mtdt)₂] (<b>7</b>) large magnetic susceptibilities indicative of high spin states were observed. Both electric transport properties and magnetic properties for gold and nickel [M(α-mtdt)₂] are indicative that these compounds are single component molecular conductors. Nickel ; Chemistry ; Seebeck coefficient ; Metal ; Substituent ; Diamagnetism ; Crystallite ; Magnetic susceptibility ; Inorganic chemistry ; Electrical resistivity and conductivity ; Crystallography ; Stereochemistry ; Organic chemistry ; Magnetic field Organic and Molecular Conductors Research ; Magnetism in coordination complexes ; Advanced battery technologies research
Authors: Hai-Qing Yin | Xue Jiang | Guo-Quan Liu | Sharon Elder | Bin Xu | Qing-Jun Zheng | Xuan-Hui Qu
Source: Chinese Physics B (article, 2018-11-01)
Field: Materials Science — Materials Chemistry

The materials data ecosystem: Materials data science and its role in data-driven materials discovery Since its launch in 2011, Materials Genome Initiative (MGI) has drawn the attention of researchers from across academia, government, and industry worldwide.As one of the three tools of MGI, the materials data, for the first time, emerged as an extremely significant approach in materials discovery. Data science has been applied in different disciplines as an interdisciplinary field to extract knowledge from the data. The concept of materials data science was utilized to demonstrate the data application in materials science. To explore its potential as an active research branch in the big data age, a three-tier system was put forward to define the infrastructure of data classification, curation and knowledge extraction of materials data. Big data ; Knowledge extraction ; Data extraction ; Data collection ; Research data Machine Learning in Materials Science ; X-ray Diffraction in Crystallography ; Catalysis and Oxidation Reactions
Authors: Youqu Zheng | Hu Jiangen | Guoneng Li | Lingyun Zhu | Wenwen Guo
Source: Materials (article, 2018-06-07)
Field: Materials Science — Materials Chemistry

Testing and Optimizing a Stove-Powered Thermoelectric Generator with Fan Cooling In order to provide heat and electricity under emergency conditions in off-grid areas, a stove-powered thermoelectric generator (STEG) was designed and optimized. No battery was incorporated, ensuring it would work anytime, anywhere, as long as combustible materials were provided. The startup performance, power load feature and thermoelectric (TE) efficiency were investigated in detail. Furthermore, the heat-conducting plate thickness, cooling fan selection, heat sink dimension and TE module configuration were optimized. The heat flow method was employed to determine the TE efficiency, which was compared to the predicted data. Results showed that the STEG can supply clean-and-warm air (625 W) and electricity (8.25 W at 5 V) continuously at a temperature difference of 148 °C, and the corresponding TE efficiency was measured to be 2.31%. Optimization showed that the choice of heat-conducting plate thickness, heat sink dimensions and cooling fan were inter-dependent, and the TE module configuration affected both the startup process and the power output. Thermoelectric generator ; Heat sink ; Stove ; Nuclear engineering ; Materials science ; Electricity ; Thermoelectric effect ; Thermoelectric cooling ; Automotive engineering ; Mechanical engineering ; Environmental science ; Electrical engineering ; Engineering ; Thermodynamics ; Physics Advanced Thermoelectric Materials and Devices ; Innovative Energy Harvesting Technologies ; Thermal Radiation and Cooling Technologies
Authors: Daniel Caballero
Source: ELCVIA Electronic Letters on Computer Vision and Image Analysis (article, 2018-03-05)
Field: Chemistry — Analytical Chemistry

Feature extraction algorithms from MRI to evaluate quality parameters on meat products by using data mining This thesis proposes a new methodology to determine the quality characteristics of meat products (Iberian loin and ham) in a non-destructive way. For that, new algorithms have been developed to analyze Magnetic Resonance Imaging (MRI), and data mining techniques have been applied on data obtained from the images.The general procedure consists of obtaining MRI of meat products, and applying different computer vision algorithms (texture and fractal approaches, mainly), which allow the extraction of sets of computational features. Figure 1 shows the design of the proposed procedure.To achieve this, different research have been done, based on:high-field and low-field MRI scannersdifferent acquisition sequences: Spin Echo (SE), Gradient Echo (GE) and Turbo 3D (T3D)different texture approaches: Gray Level Co-occurrence Matrix (GLCM), Gray Level Run Length Matrix (GLRLM) and Neighboring Gray Level Dependence Matrix (NGLDM)fractals algorithms: Classical Fractal Algorithm (CFA), Fractal Texture Algorithm (FTA) and One Point Fractal Texture Algorithm (OPFTA)FTA [1] and OPFTA [2] have been developed in this thesis. They allow analyzing MRI images, properly, noting OPFTA for its simplicity and lower computational cost. At the same time, the meat products, Iberian hams and loins, were also analyzed by means of physico-chemical and sensory techniques. Databases were constructed with all these data. Different data mining techniques have been applied on them: deductive (Multiple Linear Regression (MLR)) [3], classification (Decision Trees (DT) and Rules-based Systems (RBS)) [4], and prediction techniques [5-7]. Figure 2 shows the MRI images of fresh and dry-cured Iberian loins (Figure 2A and 2B) and fresh and dry-cured hams (Figure 2C and 2D).The accuracy of the analysis of the quality parameters of Iberian ham and loin is affected by the MRI acquisition sequence, the algorithm used to analyze them and the data mining technique applied. Considering the data mining techniques, MLR and DT are appropriate, respectively, to deduce physico-chemical parameters of hams, and to classify as a function of salt content in hams. Regarding to the predictive technique, MLR could be indicate it allows obtaining equations to determine the physico-chemical characteristics and sensory attributes of Iberian loins and hams with a high degree of reliability, and analyzing the quality of these meat products in a non-destructive, efficient, effective and accurate way. Computer science ; Fractal ; Algorithm ; Artificial intelligence ; Gray level ; Pattern recognition (psychology) ; Field (mathematics) ; Data mining ; Image (mathematics) ; Mathematics Spectroscopy and Chemometric Analyses ; Identification and Quantification in Food ; Neural Networks and Applications
Authors: Tomasz Majchrzak | W. Wojnowski | Tomasz Dymerski | Jacek Gębicki | Jacek Namieśnik
Source: Monatshefte für Chemie - Chemical Monthly (article, 2018-08-10)
Field: Chemistry — Organic Chemistry

A new method for real-time monitoring of volatiles in frying fumes using proton transfer reaction mass spectrometry with time-of-flight analyser To safeguard the consumers’ well-being, it is necessary to develop novel methods for determination of carcinogens in food, including volatiles generated during frying. The currently used procedures for analysis of volatile fraction of vegetable oils are not based on real-time measurements and thus do not enable the determination of carcinogenic compounds in frying fumes; instead, only the headspace or liquid fraction is sampled. In this article, described is an approach in which proton transfer reaction mass spectrometry with time-of-flight analyser (PTR-TOFMS) was used for real-time monitoring of carcinogenic compounds generated during thermal degradation of rapeseed oil. Using PTR-MS, it was possible to monitor the concentration of known volatile carcinogens according to the International Agency for Research on Cancer (IARC), alongside BTEX compounds, acrolein, and selected aldehydes. Moreover, the applicability of several supervised data analysis methods for the classification of oil samples according to their degree of thermal degradation was presented, with best results obtained using the k-nearest neighbours algorithm. Proton transfer reaction mass spectrometry is a powerful technique for the determination of carcinogenic compounds generated during thermal degradation of edible oils. Further investigation of the chemical processes which occur during frying can lead to improvement of food safety. Analyser ; Chemistry ; Mass spectrometry ; Fraction (chemistry) ; Time-of-flight mass spectrometry ; BTEX ; Chromatography ; Environmental chemistry ; Process engineering ; Benzene ; Organic chemistry Edible Oils Quality and Analysis ; Isotope Analysis in Ecology ; Advanced Chemical Sensor Technologies
Authors: Andrii Zaitsev | Fabienne Poncin‐Epaillard | A. Lacoste | Adi Kassiba | Dominique Debarnot
Source: Progress in Organic Coatings (article, 2018-12-21)
Field: Materials Science — Materials Chemistry

A multi-step cold plasma process for fine tuning of polymer nanostructuring Materials science ; Polyaniline ; Polymer ; Nanodot ; Plasma ; Deposition (geology) ; Substrate (aquarium) ; Nanotechnology ; Chemical engineering ; Surface modification ; Nanostructure ; Composite material Diamond and Carbon-based Materials Research ; Surface Modification and Superhydrophobicity ; Advanced Sensor and Energy Harvesting Materials
Authors: Satoru Takakusagi | Yasuhiro Iwasawa | Kiyotaka Asakura
Source: The Chemical Record (review, 2018-09-11)
Field: Materials Science — Materials Chemistry

Premodified Surface Method to Obtain Ultra‐Highly Dispersed Metals and their 3D Structure Control on an Oxide Single‐Crystal Surface Precise control of the three-dimensional (3D) structure of highly dispersed metal species such as metal complexes and clusters attached to an oxide surface has been important for the development of next-generation high-performance heterogeneous catalysts. However, this is not easily achieved for the following reasons. (1) Metal species are easily aggregated on an oxide surface, which makes it difficult to control their size and orientation definitely. (2) Determination of the 3D structure of the metal species on an oxide powder surface is hardly possible. To overcome these difficulties, we have developed the premodified surface method, where prior to metal deposition, the oxide surface is premodified with a functional organic molecule that can strongly coordinate to a metal atom. This method has successfully provided a single metal dispersion on an oxide single-crystal surface with the 3D structure precisely determined by polarization-dependent total reflection fluorescence X-ray absorption fine structure (PTRF-XAFS). Here we describe our recent results on ultra-high dispersions of various metal atoms on TiO<sub>2</sub> (110) surfaces premodified with mercapto compounds, and show the possibility of fine tuning and orientation control of the surface metal 3D structures. Oxide ; Metal ; Materials science ; X-ray absorption fine structure ; Crystal structure ; Single crystal ; Crystallography ; Chemistry ; Spectroscopy ; Metallurgy Catalytic Processes in Materials Science ; Iron oxide chemistry and applications ; X-ray Spectroscopy and Fluorescence Analysis
Authors: Yanbiao Liu | Xiang Liu | Shengnan Yang | Fang Li | Chensi Shen | Chunyan Ma | Manhong Huang | Wolfgang Sand
Source: Nanomaterials (article, 2018-09-05)
Field: Chemistry — Organic Chemistry

Ligand-Free Nano-Au Catalysts on Nitrogen-Doped Graphene Filter for Continuous Flow Catalysis In this study, the authors rationally designed a high-performance catalytic filter for continuous flow catalysis. The catalytic filter consisted of ligand-free nanoscale gold (nano-Au) catalysts and nitrogen-doped graphene (N-rGO). The Au catalyst was fabricated in situ onto a pre-formed N-rGO support by the NaBH₄ reduction of the Au precursor, and the size of the nano-Au was fine-tuned. A hydrothermal pretreatment of graphene oxide enriched nitrogen-containing species on the surface of two-dimensional graphene supports and enhanced the affinity of Au precursors onto the support via electrocatalytic attraction. The nano-Au catalysts acted as high-performance catalysts, and the N-rGO acted as ideal filter materials to anchor the catalysts. The catalytic activity of the as-designed catalytic filter was evaluated using 4-nitrophenol (4-NP) hydrogenation as a model catalytic reaction. The catalytic filters demonstrated superior catalytic activity and excellent stability, where a complete 4-nitrophenol conversion was readily achieved via a single pass through the catalytic filter. The as-fabricated catalytic filter outperformed the conventional batch reactors due to evidently improved mass transport. Some key operational parameters impacting the catalytic performance were identified and optimized. A similar catalytic performance was also observed for three 4-nitrophenol spiked real water samples (e.g., surface water, tap water, and industrial dyeing wastewater). The excellent catalytic activity of the nano-Au catalysts combined with the two-dimensional and mechanically stable graphene allowed for the rational design of various continuous flow catalytic membranes for potential industrial applications. Catalysis ; Graphene ; Materials science ; Nano- ; Ligand (biochemistry) ; Doping ; Filter (signal processing) ; Nanotechnology ; Nitrogen ; Chemical engineering ; Chemistry ; Organic chemistry ; Optoelectronics ; Composite material ; Computer science ; Engineering Nanomaterials for catalytic reactions ; Catalytic Processes in Materials Science ; Advanced Memory and Neural Computing
Authors: Leonel Llanos | Daniel Aravena
Source: Inorganics (article, 2018-01-27)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Effect of Low Spin Excited States for Magnetic Anisotropy of Transition Metal Mononuclear Single Molecule Magnets Rational, fine tuning of magnetic anisotropy is critical to obtain new coordination compounds with enhanced single molecule magnet properties. For mononuclear transition metal complexes, the largest contribution to zero-field splitting is usually related to the excited states of the same spin as the ground level. Thus, the contribution of lower multiplicity roots tends to be overlooked due to its lower magnitude. In this article, we explore the role of lower multiplicity excited states in zero-field splitting parameters in model structures of Fe(II) and Co(II). Model aquo complexes with coordination numbers ranging from 2 to 6 were constructed. The magnetic anisotropy was calculated by state of the art ab initio methodologies, including spin-orbit coupling effects. For non-degenerate ground states, contributions to the zero-field splitting parameter (D) from highest and lower multiplicity roots were of the same sign. In addition, their relative magnitude was in a relatively narrow range, irrespective of the coordination geometry. For degenerate ground states, the contribution from lower multiplicity roots was significantly smaller. Results are rationalized in terms of general expressions for D and are expected to be reasonably transferable to real molecular systems. Degenerate energy levels ; Multiplicity (mathematics) ; Excited state ; Anisotropy ; Ground state ; Condensed matter physics ; Chemistry ; Ab initio ; Magnet ; Physics ; Atomic physics ; Quantum mechanics ; Geometry ; Mathematics Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Metal-Catalyzed Oxygenation Mechanisms