jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Mohammad Nur‐E‐Alam | Mikhail Vasiliev
Source:  (preprint, 2019-10-24)
Field: Materials Science — Materials Chemistry

Application-specific oxide-based and metal-dielectric thin-film materials prepared by RF sputtering We report on the development of several different thin-film material systems prepared by RF magnetron sputtering at Edith Cowan University nanofabrication labs. While focusing on the RF sputtering process optimizations for new or the previously underexplored material compositions and multilayer structures, we disclose several unforeseen material properties and behaviours. We communicate research results related to the design, prototyping, and practical fabrication of high-performance magneto-optic (MO) materials, oxide based sensor components, and transparent heat regulation coatings for advanced construction and solar windows. Sputtering ; Materials science ; Fabrication ; Sputter deposition ; Nanolithography ; Thin film ; Dielectric ; Optoelectronics ; Oxide ; Nanotechnology ; Engineering physics ; Metallurgy ; Engineering Ferroelectric and Piezoelectric Materials ; Acoustic Wave Resonator Technologies ; Advanced Fiber Optic Sensors
Authors: Zh. Karipbaev | Д. А. Мусаханов | В. М. Лисицын | Gulnur Alpyssova | М. Г. Голковский | Л. А. Лисицына | А. Т. Тулегенова | A Akylbekov | Alma Dauletbekova | K. Balabekov | А. Л. Козловский | А. Usseinov
Source: Bulletin of the Karaganda University Physics Series (article, 2019-12-30)
Field: Materials Science — Materials Chemistry

Synthesis, the study of the structure of YAG and YAGG phosphors in the radiation field In the present work, an attempt is made to synthesize a phosphor using powerful hard radiation fluxes. The surface, elemental composition, structure, and luminescent characteristics of the obtained YAG:Ce ceramics were studied. Ceramics have a heterogeneous structure. The main phase of the obtained ceramics is YAG, which ranges from 72 to 91 % of the total volume of samples. The remaining volume of the samples consists of the Al2O3 and CeO2 phases. The synthesized ceramics has the characteristic properties of YAG:Ce, YAGG:Ce phosphors. The surface condition and elemental surface composition of the synthesized ceramic sample were studied using a scanning electron microscope. The images showed that there are particles with awell-defined faceting, which indicates the formation of microcrystals. X-ray diffraction analysis of the synthesized ceramic samples was carried out on a diffractometer. X-ray diffraction analysis showed that the resulting ceramic has a high degree of crystallinity. The quantitative phase dependence was determined in the TOPAS-4.2 program. The results of measuring the luminescence spectra measured upon excitation of the specimen split surface are presented. The maximum luminescence of YAG:Ce ceramics accounts for 555 nm, the half-width of the band is 0.45 eV. In YAGG:Ce ceramics, the luminescence maximum at 555 nm, the half-width of the band is 0.48 eV. Phosphor ; Radiation ; Materials science ; Field (mathematics) ; Optics ; Optoelectronics ; Physics ; Mathematics Luminescence Properties of Advanced Materials ; Radiation Detection and Scintillator Technologies ; Terahertz technology and applications
Authors: Matilde Eredia
Source: SPIRE - Sciences Po Institutional REpository (preprint, 2019-05-24)
Field: Materials Science — Materials Chemistry

2D materials : exfoliation in liquid-phase and electronics applications This thesis is devoted to the production in liquid-phase of two-dimensional materials, by using approaches that may enable mass production of graphene and related materials. We aim to overcome some issues that are critical for the processing and practical use of 2D materials-inks and to provide a deep understanding of the structure-properties relationship in such materials being mandatory steps toward their future applications. This thesis mainly focuses on ultrasound-induced liquid-phase exfoliation and electrochemical exfoliation of graphene and molybdenum disulfide, which have been chosen as prototypical 2D materials. The synthetic approaches have been combined with a multiscale physico-chemical and electrical characterization of the produced materials, by employing techniques such as AFM, XPS and Raman spectroscopy. Applications in the field of sensing and electronics have been explored and allowed to demonstrate that liquid-phase exfoliation approaches can be conveniently employed to achieve a fine control on the properties of 2D materials paving the way to their integration as active materials in novel multifunctional devices. Humanities ; Physics ; Materials science ; Physical chemistry ; Philosophy ; Chemistry Graphene research and applications ; 2D Materials and Applications
Authors: Matthias Kirste | Thomas Brietzke | Hans‐Jürgen Holdt | Uwe Schilde
Source: Zeitschrift für Kristallographie - New Crystal Structures (article, 2019-08-23)
Field: Chemistry — Organic Chemistry

The crystal structure of 1,12-diazaperylene, C<sub>18</sub>H<sub>10</sub>N<sub>2</sub> Abstract C 18 H 10 N 2 , monoclinic, P 2 1 / c (no. 14), a = 7.9297(9) Å, b = 11.4021(14) Å, c = 13.3572(15) Å, β = 105.363(8)°, V = 1164.5(2) Å 3 , Z = 4, R gt ( F ) = 0.0325, wR ref ( F 2 ) = 0.0774, T = 210(2) K. Monoclinic crystal system ; Crystal structure ; Crystallography ; Chemistry ; Crystal (programming language) ; Materials science Synthesis and Properties of Aromatic Compounds ; Molecular spectroscopy and chirality ; Crystallography and molecular interactions
Authors: Miran Lemmerer | Michaël Abraham | Bogdan R. Brutiu | Alexander Roller | Michael Widhalm
Source: Molecules (article, 2019-08-26)
Field: Chemistry — Organic Chemistry

Synthesis, Structure, and Reactivity of Binaphthyl Supported Dihydro[1,6]diazecines A short approach to chiral diaza-olefines from protected 2,2'-diamino-1,1'-binaphthyl is presented. <i>Cis</i>- and <i>trans</i>-olefines can be selectively obtained by twofold <i>N</i>-allylation followed by RCM or by bridging a 2,2'-diamino-1,1'-binaphthyl precursor with <i>trans</i>-1,4-dibromo-2-butene. Deprotection afforded <i>cis</i>- and <i>trans</i>-dihydro[1,6]diazecines <b>1</b> in 58 and 64% overall yield. The reactivity of the but-2-ene-1,4-diyl fragment was investigated yielding corresponding epoxides, diols, and mono- and dibromo products. In several cases rearrangements and participation of the proximate <i>N</i>-Boc group was observed. In no case could allylic substitution be accomplished. From 13 compounds X-ray structure analyses could be obtained. Allylic rearrangement ; Chemistry ; Reactivity (psychology) ; Yield (engineering) ; Stereochemistry ; Medicinal chemistry ; Organic chemistry ; Catalysis Synthetic Organic Chemistry Methods ; Axial and Atropisomeric Chirality Synthesis ; Asymmetric Synthesis and Catalysis
Authors: Markus Joksch | Anke Spannenberg | Torsten Beweries
Source: Acta Crystallographica Section E Crystallographic Communications (article, 2019-06-21)
Field: Chemistry — Organic Chemistry

Intermolecular hydrogen bonding in isostructural pincer complexes [OH-(<sup> <i>t</i>-Bu</sup>POCOP<sup> <i>t</i>-Bu</sup>)<i>M</i>Cl] (<i>M</i> = Pd and Pt) In the crystal structure of the isostructural title compounds, namely {2,6-bis-[(di-<i>tert</i>-butyl-phosphan-yl)-oxy]-4-hy-droxy-phen-yl}chlorido-palladium(II), [Pd(C<sub>22</sub>H<sub>39</sub>O<sub>3</sub>P<sub>2</sub>)Cl], <b>1</b>, and {2,6-bis-[(di-<i>tert</i>-butyl-phosphan-yl)-oxy]-4-hy-droxy-phen-yl}chlorido-platinum(II), [Pt(C<sub>22</sub>H<sub>39</sub>O<sub>3</sub>P<sub>2</sub>)Cl], <b>2</b>, the metal centres are coordinated in a distorted square-planar fashion by the POCOP pincer fragment and the chloride ligand. Both complexes form strong hydrogen-bonded chain structures through an inter-action of the OH group in the 4-position of the aromatic POCOP backbone with the halide ligand. Isostructural ; Pincer movement ; Chemistry ; Ligand (biochemistry) ; Hydrogen bond ; Crystal structure ; Crystallography ; Intermolecular force ; Stereochemistry ; Halide ; Medicinal chemistry ; Molecule ; Inorganic chemistry ; Organic chemistry ; Catalysis Organometallic Complex Synthesis and Catalysis ; Metal complexes synthesis and properties ; Asymmetric Hydrogenation and Catalysis
Authors: Illia Timashkov | Yuliia Shlapa | Sergiy Solopan | А. Г. Белоус
Source: Ukrainskij himičeskij žurnal (article, 2019-10-16)
Field: Materials Science — Electronic, Optical and Magnetic Materials

SYNTHESIS AND CRYSTALLOCHEMICAL PROPERTIES OF Ce-SUBSTITUTED NANOPARTICLES OF MANGANITE (La,Sr)MnO3 Serious of Ce-substituted lanthanum-strontium man-ganites La0.7–xSr0.3CexMnO3 (x = 0–0.2) nanoparticles were synthesized by sol-gel method with further heat treatment of precursors at 800 °C. Crystallographic properties of obtained nanoparticles were investiga-ted by X-ray diffraction method. According to XRD data, it was established that the substitution of lan-thanum ions by cerium in the crystalline structure and formation of single-phased nanoparticles occurs only up to 5 % mol. of Ce regardless of the heating temperature. Linear decreasing the cell volume of nanoparticles in this concentration range of Ce satis-fies the Vegard law and indicates on the formation of a continuous series of solid solutions with the dis-torted perovskite up to 5 % of Ce. At higher concen-trations of Ce there are additional peaks on the XRD patterns, which point on the formation of an addi-tional phase of CeO2. According to TEM studies, it was calculated that the average size of was 30–40 nm. To estimate heating efficiency of synthesized nanoparticles in the alternating magnetic field, mag-netic fluids based on the synthesized nanoparticles and aqueous dextran solution were prepared. It was shown that they effectively heated up to controlled temperatures in an alternating magnetic field, and their heating efficiency was directly proportional to the increase of the concentration of cerium. Accor-ding to the results of the complex studies, it was shown the possibility to synthesize single-phase Ce-substituted nanoparticles of manganite with a pe-rovskite structure. It was established that cerium does not significantly influence on the change of magnetic properties of such nanoparticles and they are promising for further investigations as the in-ducers of magnetic hyperthermia, as well as for the biological tests. Cerium ; Nanoparticle ; Materials science ; Manganite ; Aqueous solution ; Lanthanum manganite ; Lanthanum ; Perovskite (structure) ; Phase (matter) ; Analytical Chemistry (journal) ; Chemical engineering ; Nanotechnology ; Inorganic chemistry ; Crystallography ; Physical chemistry ; Chemistry ; Metallurgy ; Ferromagnetism ; Organic chemistry Magnetic and transport properties of perovskites and related materials ; Laser-Ablation Synthesis of Nanoparticles ; Gas Sensing Nanomaterials and Sensors
Authors: Akinobu Z. Suzuki | Yukiko Shiraishi | Hanami Aoki | Hirona Sasaki | Rei Watahiki | Toshiaki Furuta
Source: Journal of Visualized Experiments (article, 2019-10-15)
Field: Materials Science — Materials Chemistry

Design, Synthesis, and Photochemical Properties of Clickable Caged Compounds Caged compounds enable the photo-mediated manipulation of the cell physiology with high spatiotemporal resolution. However, the limited structural diversity of currently available caging groups and the difficulties in synthetic modification without sacrificing their photolysis efficiencies are obstacles to expanding the repertoire of caged compounds for live cell applications. As the chemical modification of coumarin-type photo-caging groups is a promising approach for the preparation of caged compounds with diverse physical and chemical properties, we report a method for the synthesis of clickable caged compounds that can be modified easily with various functional units via the copper(I)-catalyzed Huisgen cyclization. The modular platform molecule contains a (6-bromo-7-hydroxycoumarin-4-yl)methyl (Bhc) group as a photo-caging group, which exhibits a high photolysis efficiency compared to those of the conventional 2-nitrobenzyls. General procedures for the preparation of clickable caged compounds containing amines, alcohols, and carboxylates are presented. Additional properties such as the water solubility and cell targeting ability can be readily incorporated into clickable caged compounds. Furthermore, the physical and photochemical properties, including the photolysis quantum yield, were measured and were found to be superior to those of the corresponding Bhc caged compounds. The described protocol could therefore be considered a potential solution for the lack of structural diversity in the available caged compounds. Photodissociation ; Chemistry ; Functional group ; Click chemistry ; Combinatorial chemistry ; Molecule ; Photochemistry ; Organic chemistry ; Polymer Photochromic and Fluorescence Chemistry ; Luminescence and Fluorescent Materials ; Nanoplatforms for cancer theranostics
Authors: University Of Potsdam, Institute Of Geosciences
Source: DIGITAL.CSIC (Spanish National Research Council (CSIC)) (article, 2019-01-01)
Field: Chemistry — Analytical Chemistry

RAA2019 These abstracts result from the 10th International Congress on the Application of Raman Spectroscopy in Art and Archaeology held 03.09. – 07.09.2019 in Potsdam (Germany). The RAA is an established biennial international conference series. Since the beginning in 2001, the RAA conferences promote Raman Spectroscopy and play an important role in increasing the field of its applications in art history, history, archaeology, palaeontology, conservation and restoration, museology, degradation of cultural heritage, archaeometry, etc. Furthermore, the development of new instrumentation, especially for non-invasive measurements, receives great attention. The Congress covers all topics of Raman spectroscopic applications in art and archaeology and focuses on the following themes: • Material characterization and degradation processes • Conservation issues affecting cultural heritage • Raman spectroscopy of biological and organic materials • Surface enhanced Raman spectroscopy • Chemometrics in Raman spectroscopy • Development of Raman techniques • New Raman instrumentation and applications in cultural heritage objects investigations • Raman spectroscopy in paleontology, paleoenvironment and archaeology Raman spectroscopy ; Chemistry ; Optics ; Physics Spectroscopy and Chemometric Analyses
Authors: Omar Sadek | David M. Perrin | Emmanuel Gras
Source:  (preprint, 2019-12-05)
Field: Chemistry — Organic Chemistry

Straightforward convergent access to 2-arylated polysubstituted benzothiazoles A modular access to 2,4 disubstituted benzothiazoles has been achieved though the intermediacy of 4-bromo-2-iodobenzothiazole. The difference in reactivity of both halogens was advantageously exploited to achieve sequential Suzuki-Miyaura cross-coupling giving access to a range of polyaromatic derivatives featuring a central benzothiazole core. Benzothiazole ; Halogen ; Modular design ; Reactivity (psychology) ; Combinatorial chemistry ; Chemistry ; Computer science ; Core (optical fiber) ; Organic chemistry ; Programming language ; Telecommunications Catalytic Cross-Coupling Reactions ; Chemical synthesis and alkaloids ; Phenothiazines and Benzothiazines Synthesis and Activities
Authors: Brigid Conroy
Source: cIRcle (University of British Columbia) (article, 2019-01-01)
Field: Chemistry — Organic Chemistry

Investigating the physiological function of a Staphylococcus aureus Ntn-hydrolase The N-terminal nucleophile (Ntn)-hydrolase structural superfamily consists of several classes of enzymes, including the penicillin V acylases (PVAs), bile salt hydrolases, and N-acylhomoserine lactone (AHL) acylases. The PVAs use an N-terminal cysteine residue to hydrolyze the amide bond in penicillin V and are most closely related to the bile salt hydrolases. PVAs are encoded by many environmental and pathogenic bacteria and are of great importance in the pharmaceutical industry because the product of penicillin V hydrolysis is used in the production of semi-synthetic antibiotics. Despite their industrial value, the physiological function of the PVAs remains unknown. The opportunistic human pathogen Staphylococcus aureus encodes an Ntn-hydrolase (gene locus SAUSA300_0269). Several potential substrates of SAUSA300_0269 were tested and it was demonstrated to hydrolyze penicillin V but show no activity towards the bile salt glycocholic acid. Based on the observed activity, SAUSA300_0269 was renamed to SaPVA. This enzyme also hydrolyzed several AHLs, which are quorum sensing molecules used by Gram-negative bacteria. SaPVA is the first example of a PVA from a Gram-positive bacterium that cross-reacts with AHLs. The enzyme displayed a preference for unsubstituted AHLs with an acyl chain of six or more carbons. Growth experiments did not support a role for SaPVA in protection of S. aureus against the toxicity of 3-oxo-C12-HSL, an AHL produced by Pseudomonas aeruginosa. Two siderophores used by S. aureus, enterobactin and staphyloferrin A, were also tested as substrates, but SaPVA did not show activity towards either molecule. To obtain further insight into the substrates of SaPVA, the crystal structure was solved to 1.9 Å resolution and compared with those of other characterized PVAs from Gram-positive and Gram-negative bacteria. Similarity in the overall structure and substrate-binding loops of PVAs from Gram-positive bacteria suggest that these enzymes act on similar substrates. Molecular docking was used to predict the binding modes of penicillin V and various AHLs to SaPVA. Docking results provided some clues about the structural features that may be present in physiological substrates of SaPVA, including one or more rings, as well as an aryl group or hydrophobic acyl chain. Staphylococcus aureus ; Microbiology ; Chemistry ; Function (biology) ; Biology ; Bacteria ; Cell biology ; Genetics Click Chemistry and Applications ; Biotin and Related Studies ; Biochemical and Molecular Research
Authors: Sierra Bonney
Source: NCSU Libraries Repository (North Carolina State University Libraries) (article, 2019-11-05)
Field: Materials Science — Biomaterials

Regenerative Medicine: Effects of Plant Bioactives on Muscle Protection and Wound Healing. Medicine: Effects of Plant Bioactives on Muscle Protection and Wound Healing.(Under the direction of Dr. Debora Esposito Wound healing ; Regenerative medicine ; Regeneration (biology) ; Medicine ; Traditional medicine ; Biology ; Surgery ; Cell biology ; Stem cell Electrospun Nanofibers in Biomedical Applications ; Nutrition, Genetics, and Disease ; Tissue Engineering and Regenerative Medicine
Authors: Utai Meekum | Waree Wangkheeree
Source: BioResources (article, 2019-08-05)
Field: Materials Science — Polymers and Plastics

Manufacturing engineered wood panels from rice husk flake reinforced with glass and carbon fibers using epoxy adhesive Rice husk flake (RHF) engineered wood panels were manufactured from unmodified rice husk flake in its original form and epoxy adhesive. One of the main objectives for using the original form of RHF was to minimize the manufacturing cost and processing time for treating the flake. Two types of short randomized reinforcements namely carbon fiber (CF) and glass fiber (GF) were employed to enhance the mechanical properties. The optimal compression pressure for the manufacturing process was 120 kgf/cm2. The short randomized CF and GF reinforcements were employed and investigated. An outstanding enhancement in mechanical performances was observed. At the given short fiber content, the CF showed superiority as reinforcement to the GF. The adhesive exhaustion was evidenced when the reinforcement loading exceed 40 wt%. In the combined CF/GF short fibers at constant 40 wt% loading, the mechanical performance was reduced by increasing the GF portion. Flake ; Husk ; Materials science ; Epoxy ; Composite material ; Adhesive ; Reinforcement ; Fiber ; Composite number ; Botany Natural Fiber Reinforced Composites ; Additive Manufacturing and 3D Printing Technologies ; Wood Treatment and Properties
Authors: C. Marinelli | E. Mariotti | Nicolò Papi | Francesco Sarri | A. Ziccardi | R. Cecchi | Leonardo Stiaccini | Cecilia Viti | A. Khanbekyan | I. A. Gladskikh | Pavel A. Petrov | T. A. Vartanyan
Source: Journal of the Siena Academy of Sciences (article, 2019-09-05)
Field: Materials Science — Materials Chemistry

A NEW SETUP FOR THE STUDY OF ADSORPTION/DESORPTION PROCESSES AND NANOPARTICLES FORMATION IN POROUS ALUMINA We present a setup devoted to the study of adsorption and desorption processes of alkali atoms after deposition on a 300 nm thick porous alumina substrate in an Ultra High Vacuum chamber. Rubidium atoms, delivered by a dispenser source, enter the 20-30 nm diameter pores, diffuse in and stick to their walls. A 1 W power laser is used in order to induce detachment and take the atoms back in the vapor phase in a very tight confinement region. The desorbed atoms coming out the sample can be monitored via both a resonant optical detection and an electronic amplifier after ionization. The desorbing laser is also able to promote the formation of Rubidium nanoparticles, as the high Rb vapor density in the pores favors aggregation around nucleation point defects. In this way, the apparatus allows for the study of the fundamental processes related to atom – surface interactions in presence of light as well as of several promising application to nanomaterials. Rubidium ; Nucleation ; Desorption ; Nanoparticle ; Materials science ; Chemical physics ; Adsorption ; Nanomaterials ; Alkali metal ; Atom (system on chip) ; Chemical engineering ; Nanotechnology ; Analytical Chemistry (journal) ; Chemistry ; Physical chemistry Mesoporous Materials and Catalysis ; Anodic Oxide Films and Nanostructures ; Photonic Crystals and Applications
Authors: Hiroyasu Nishi | Tetsu Tatsuma
Source: Electrochemistry (article, 2019-08-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Electrochemical and Photoelectrochemical Applications of Plasmonic Metal and Compound Nanoparticles Metal nanoparticles (NPs) that exhibit bright colors have been used as coloring agents of glass artifacts since before Christ. After the origin of the coloration, localized surface plasmon resonance (LSPR), was elucidated, their application has been expanded widely. This account focuses on electrochemical and photoelectrochemical applications of the plasmonic metal and compound NPs. Because LSPR is based on collective oscillation of free electrons in a NP in resonance with electric field oscillation of light, the resonant wavelength can be tuned electrochemically by transferring electrons to or from the NP. On this basis, we developed a new class of plasmonic sensors without gratings, and near infrared electrochromic smart windows. Meanwhile, resonant NPs exhibit charge separation at the interface with a semiconductor such as TiO2. We studied this phenomenon, plasmon-induced charge separation (PICS), in particular about mechanisms including behavior of energetic carriers (hot holes and electrons), by using a wide variety of plasmonic NPs with different morphologies and compositions. Knowledge thus obtained was exploited for nanofabrication and development of near infrared PICS devices. Plasmon ; Surface plasmon resonance ; Materials science ; Electrochromism ; Nanoparticle ; Optoelectronics ; Nanotechnology ; Semiconductor ; Electron ; Surface plasmon ; Electrode ; Chemistry ; Physics Gold and Silver Nanoparticles Synthesis and Applications ; Plasmonic and Surface Plasmon Research ; Copper-based nanomaterials and applications