jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Markus Krüger | Stefan Liebig | Uwe Ruschewitz
Source: Zeitschrift für anorganische und allgemeine Chemie (article, 2020-02-11)
Field: Chemistry — Inorganic Chemistry

K<i><sub>x</sub></i>Rb<sub>2–<i>x</i></sub>PdC<sub>2</sub>: A Solid Solution of a Quaternary Acetylide with Vegard Behavior By reacting the ternary acetylides K 2 PdC 2 and Rb 2 PdC 2 at 300 °C under inert conditions a complete solid solution K x Rb 2– x PdC 2 with x = 0–2 was obtained, which was followed and confirmed by synchrotron powder diffraction data. This solid solution shows ideal Vegard behavior, as predicted by Hume‐Rothery rules for ΔV &lt; 15 % (ΔV = 9.2 % for K + /Rb + ). According to the powder diffraction data the formation of the quaternary acetylides seems to occur via diffusion of the alkali metal ions, whereas the 1 ∞ [Pd 0 (C 2 ) 2/2 2– ] chains remain unaffected during this reaction. Solid solution ; Acetylide ; Ternary operation ; Diffraction ; Powder diffraction ; Alkali metal ; Crystallography ; Synchrotron ; X-ray crystallography ; Ion ; Chemistry ; Diffusion ; Analytical Chemistry (journal) ; Materials science ; Inorganic chemistry ; Physical chemistry ; Thermodynamics ; Stereochemistry ; Physics ; Organic chemistry Inorganic Chemistry and Materials ; MXene and MAX Phase Materials
Authors: Alessandra Leonhardt | Thomas Nuytten | César Javier Lockhart de la Rosa | Stefanie Sergeant | Vivek Mootheri | Cedric Huyghebaert | Stefan De Gendt
Source: ECS Journal of Solid State Science and Technology (article, 2020-10-01)
Field: Materials Science — Materials Chemistry

Trap Density Assessment on Multilayer WS<sub>2</sub> using Power-Dependent Indirect Photoluminescence Material or interface defectivity assessment of 2D materials remains a challenge, specifically in terms of simple techniques which can be integrated in a CMOS process line. Here we demonstrate an optical technique that assesses interface trap densities, based on the indirect photoluminescence emission. We achieved that by demonstrating the modulation of the indirect/direct photoluminescence peak intensity ratio by the exciton concentration and then linking the modulation to the trap-sensitive non-radiative Auger recombination. Calibration is achieved through theoretical modeling of the recombination mechanisms and, as an example of the methodology, a trap density between 1.6 × 10 10 cm −2 and 1.2 × 10 11 cm −2 is extracted from (hBN/)WS 2 /SiO 2 structures. Photoluminescence ; Materials science ; Trap (plumbing) ; Optoelectronics ; Exciton ; Spontaneous emission ; Auger effect ; Recombination ; Modulation (music) ; Atomic physics ; Auger ; Optics ; Condensed matter physics ; Physics ; Laser ; Chemistry 2D Materials and Applications ; MXene and MAX Phase Materials ; Ga2O3 and related materials
Authors: Joachim Emeka Arikibe | Roselyn Lata | David Rohindra
Source: Key engineering materials (article, 2020-05-05)
Field: Materials Science — Biomaterials

Synthesis, Preparation and Characterization of Amine-Induced Bacterial Cellulose-Poly(Vinyl Alcohol) Semi-Interpenetrating Network Hydrogel Bacterial cellulose (BC) was synthesized using Gluconacetobacter xylinus (BCRC 14182). Synthesized BC was powdered and dissolved in Bis(ethylenediamine) copper (II) hydroxide (Cuen) solution to introduce the amine (NH 2 ) group onto the BC network to yield modified BC (mBC) which was then blended with poly (vinyl alcohol) (PVA) and subsequently crosslinked with genipin (Gp). Pristine, modified and crosslinked hydrogels were studied using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and swelling behavior in water. FTIR revealed a distortion on the BC network chain via a reduction in the absorption of OH peak of mBC and the emergence of peaks at 1587 and 1560 cm -1 attributed to N-H stretching of the induced NH 2 group. SEM confirmed the 3-D fibril and porous structure of BC which became distorted after modification and crosslinking. The hydrogels showed equilibrium water content of 86.5%, 67.5%, 66.7% and 33.0 % for BC, PVA, mBC-PVA and mBC-PVA-Gp, respectively. The decreased swelling in mBC-PVA-Gp indicated that genipin was able to crosslink the modified BC. Vinyl alcohol ; Bacterial cellulose ; Fourier transform infrared spectroscopy ; Genipin ; Swelling ; Polymer chemistry ; Nuclear chemistry ; Materials science ; Self-healing hydrogels ; Cellulose ; Scanning electron microscope ; Absorption of water ; Chemical engineering ; Chemistry ; Chitosan ; Organic chemistry ; Composite material ; Polymer Advanced Cellulose Research Studies ; Hydrogels: synthesis, properties, applications ; Polysaccharides and Plant Cell Walls
Authors: Piotr Jankowski
Source: Acta Mechanica et Automatica (article, 2020-09-01)
Field: Materials Science — Materials Chemistry

Effect of Kerr Foundation and in-Plane Forces on Free Vibration of FGM Nanobeams with Diverse Distribution of Porosity Abstract In the present paper, the effect of diverse distribution of functionally graded porous material and Kerr elastic foundation on natural vibrations of nanobeams subjected to in-plane forces is investigated based on the nonlocal strain gradient theory. The displacement field of the nanobeam satisfies assumptions of Reddy higher-order shear deformation beam theory. All the displacements gradients are assumed to be small, then the components of the Green-Lagrange strain tensor are linear and infinitesimal. The constitutive relations for functionally graded (FG) porous material are expressed by nonlocal and length scale parameters and power-law variation of material parameters in conjunction with cosine functions. It created possibility to investigate an effect of functionally graded materials with diverse distribution of porosity and volume of voids on mechanics of structures in nano scale. The Hamilton’s variational principle is utilized to derive governing equations of motion of the FG porous nanobeam. Analytical solution to formulated boundary value problem is obtained in closed-form by using Navier solution technique. Validation of obtained results and parametric study are presented in tabular and graphical form. Influence of axial tensile/compressive forces and three different types of porosity distribution as well as stiffness of Kerr foundation on natural frequencies of functionally graded nanobeam is comprehensively studied. Boundary value problem ; Materials science ; Porosity ; Vibration ; Mechanics ; Functionally graded material ; Stiffness ; Classical mechanics ; Variational principle ; Material properties ; Equations of motion ; Porous medium ; Hamilton's principle ; Displacement (psychology) ; Mathematical analysis ; Physics ; Mathematics ; Composite material Nonlocal and gradient elasticity in micro/nano structures ; Composite Structure Analysis and Optimization ; Numerical methods in engineering
Authors: Penggui Huang | Fan Zhao | Xiaoping Li | Wu ZhangKang | Zheng Zhu | Yanfeng Zhang
Source:  (article, 2020-11-01)
Field: Chemistry — Organic Chemistry

Variant transfer learning for wood recognition Wood classification and recognition technology has always been a research hotspot and difficulty in the field of materials engineering. Early wood classification and recognition technology focused on the extraction of features. At this stage, wood classification can automatically extract wood picture features and classify and recognize them. However, this method requires more wood samples, so transfer learning technology is used to solve the problem of insufficient sample numbers. In a mixed data set of public coniferous and broad-leaved tree species, the recognition accuracy and convergence speed of the migration learning method are not enough. Therefore, we have improved the transfer learning technology so that it can be trained quickly and has a higher recognition accuracy. Our method has an accuracy of 93.07% for the recognition of this data set, which is higher than the method used by the data provider. And compared with previous methods, this method has higher recognition accuracy and more stable recognition performance. Computer science ; Transfer of learning ; Artificial intelligence ; Pattern recognition (psychology) ; Feature extraction ; Machine learning ; Field (mathematics) ; Mathematics Wood and Agarwood Research ; Industrial Vision Systems and Defect Detection ; Advanced Image and Video Retrieval Techniques
Authors: Melodie Christensen | Lars P. E. Yunker | Folarin Adedeji | Florian Häse | Loı̈c M. Roch | Tobias Gensch | Gabriel dos Passos Gomes | Tara Zepel | Matthew S. Sigman | Alán Aspuru‐Guzik | Jason E. Hein
Source: ChemRxiv (preprint, 2020-11-02)
Field: Materials Science — Materials Chemistry

Data-science driven autonomous process optimization Autonomous process optimization involves the human intervention-free exploration of a range of pre-defined process parameters in order to improve responses such as reaction yield and product selectivity. Utilizing off-the-shelf components, we developed a closed-loop system capable of carrying out parallel autonomous process optimization experiments in batch with significantly reduced cycle times. Upon implementation of our system in the autonomous optimization of a palladium-catalyzed stereoselective Suzuki-Miyaura coupling, we found that the definition of a set of meaningful, broad, and unbiased process parameters was the most critical aspect of a successful optimization. In addition, we found that categorical parameters such as phosphine ligand were vital to determining the reaction outcome. To date, categorical parameter selection has relied on chemical intuition, potentially introducing an element of bias into the experimental design. In seeking a systematic method for the selection of a diverse set of phosphine ligands fully representative of the chemical space, we developed a strategy that leveraged computed molecular descriptor clustering analysis. This strategy allowed for the successful autonomous optimization of a stereoselective Suzuki-Miyaura coupling between a vinyl sulfonate and an arylboronic acid to selectively generate the E-product isomer in high yield. Categorical variable ; Computer science ; Process optimization ; Process (computing) ; Mathematical optimization ; Biochemical engineering ; Mathematics ; Machine learning ; Engineering Machine Learning in Materials Science ; Innovative Microfluidic and Catalytic Techniques Innovation ; Gene expression and cancer classification
Authors: E.H. El-Ghazzawy | T.M. Meaz | M. SEADA | D Menzel | A Feldhoff | V epelk | J Amighian | M Myndyk | M Nasr Isfahani | S Hosseini | A Asadnia | M Mohamed | A Wahba | M Yehia | R Dhiman | S Taneja | V Reddy | K Chae | Y Lee | J Lee | S Lee | E El-Ghazzawy | S Alamri | H Badehian | H Salehi | M Ghoohestani | M Amer | A Matsuda | G Kawamura | R El-Shater | T Meaz | F Fakhry | M Raghasudha | D Ravinder | P Veerasomaiah | A Manikandan | M Durka | S Antony | B Rao | O Caltun | W Cho | C Kim | R Kotnala | S Kumar | J Shah | M Alimuddin | R Hashim | Shirsath | M Lakshmi | K Kumar | K Thyagarajan | P Priyadharsini | A Pradeep | P Rao | G Chandrasekaran | S Saafan | A Mostafa | H El-Ghazally | H Ibach | H Luth | K Modi | S Shah | N Pujara | T Pathak | N Vasoya | I Jhala | S Patange | S Shirsath | K Lohar | S Algude | S Kamble | N Kulkarni | D Mane | K Jadhav | F Tehrani | V Daadmehr | A Rezakhani | R Akbarnejad | S Gholipour | S Singhal | S Bhukal | J Singh | K Chandra | S Bansal | Y Kannan
Source: Egyptian journal of solids (article, 2020-10-01)
Field: Materials Science — Materials Chemistry

Controlling the Structural and Physical Properties of as-Synthesized Co-Mn Ferrite Nanoparticles by Adding Cr Ions In this paper, mixed spinel Co-Mn-Cr ferrite with varying chromium content have been investigated to deduce the relation between the structure and some physical properties; electric, optical and magnetic. Nano-crystalline Co0.7Mn0.3CrxFe2-xO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1) were synthesized via co-precipitation route. The obtained particle size from transmission electron microscope (TEM) micrographs is close to the crystallite size calculated from X-ray diffraction (XRD) by Sherrer’s formula, and the particle size distribution is regular. The infrared spectra represent two strong absorption bands around 600 - 400 cm−1, which confirm the presence of M-O stretching bond. The mechanical properties enhanced by adding Cr3+ ions. The optical band-gap calculated from UV-visible spectroscopy is quite affected by adding Cr3+ ions because of particle size reduction. The saturation magnetization (Ms) and the coercivity (Hc) decrease with Cr3+ ions substitution. The variations of the electrical conductivity and drift mobility with temperature were also investigated. The conduction mechanism changed from electron hopping to polaron hopping by raising the temperature. Superparamagnetic Co0.7Mn0.3CrxFe2-xO4 (x ≥ 0.6) nanocrystals can be used in biomedical applications and low power-loss applications. The sample Co0.7Mn0.3Cr0.2Fe1.8O4 has high squareness ratio (Mr/Ms) and, it may be suitable for memory applications. Ferrite (magnet) ; Materials science ; Nanoparticle ; Ion ; Chemical engineering ; Metallurgy ; Nanotechnology ; Composite material ; Chemistry ; Engineering ; Organic chemistry Magnetic Properties and Synthesis of Ferrites ; Iron oxide chemistry and applications
Authors: Ирина Александровна Христофорова | Alexander I. Khristoforov
Source: IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA (article, 2020-04-15)
Field: Materials Science — Polymers and Plastics

RESEARCH FOR FORMING POROUS STRUCTURES BASED ON PVC In this work, we report on phase equilibrium in systems «plasticizer mix - blowing agent». Dioctiphthalate, butylbenzylphthalate and dicresyl phosphate were used as plasticizer, and simple oligoesters (ethylene glycol, diethylene glycol, triethylene glycol) served as a blowing agent. We conducted an experiment and built triple phase diagrams. Diphenylcresylphosphate proved to be fully compatible with diethylene and triethylene glycol, but not to the ethylene one. Triple systems «Butyl benzyl phthalate - Diphenylcresylphosphate - Simple oligoesters» turned out to be homogeneous for several created compounds. To achieve this for a triple system, the minimal quantity threshold is either 20% of triethylene glycol or 30% of diethylene. As for the case of dioctyl phthalate for second plasticizer, the minimal threshold for blowing agents is 70%. We constructed a device that allows to detect phase equilibrium for liquid systems. We devised several compounds and a technological proccess for creating porous PVC-based membranes using thermal molding. We selected such molding due to several advantages when compared to other methods for producing porous membranes, such as: required density, elasticity, open pores, and narrow pore size distribution. We managed to create several samples based on emulsion type PVC, butyl benzyl phthalate, diphenylcresyl phosphate, diethylene and triethylene glycol. During the phase inversion thermal process temperature should be around 180 degrees of celsium. Porous materials have the following properties: open porosity 38-44%, breaking strength 1.0 – 1.2 MРa, relative extension 43-63%, maximal pore size (2.3 – 2.8)·10-6 m, average pore size (0.5 – 1.1)·10-6 m. Triethylene glycol ; Diethylene glycol ; Plasticizer ; Materials science ; Ethylene glycol ; Phthalate ; Blowing agent ; Chemical engineering ; Porosity ; Polymer chemistry ; Molding (decorative) ; Composite material ; Polyurethane Polymer Science and PVC
Authors: Kokkanda Ratnaih | Venkata Prasad | S. Ramesh | G. S. V. R. K. Choudary | Srinivasa Rao Kurapati | Srinivasa Kurapati | R Kesavamoorthi | C Raja | G Luo | W Zhou | J Li | Z Zhou | G Jiang | W Li | S Tang | Y Du | X Wu | W Chen | W Wu | J Wu | Q Wang | T Shinde | A Gadkari | P Vasambekar | E Hamid | M Hamid | G Kurtulus | M Zhang | X Gao | Z Zi | J Dai | J Wang | S Chou | C Liang | X Zhu | Y Sun | H Liu | G Pozolpez | S Silvetti | S Urreta | A Carreras | G Bazuev | O Gyrdasova | S Novikov | A Yu | Kuznetsov | R Hochschild | H Fuess | S Jacobo | P Bercoff | A Ghasemi | M Mousavinia | S Ramesh | B Dhanalakshmi | B Chandra Sekhar | P Subba Rao | B Rao | Darko Makovec | Aljosa Kosak | Andrej nidari | Miha Drofenik | P Yaseneva | M Bowker | G Hutchings | K Huiwu | Y Chiungchang | G Wang | A Nandapure | S Kondawar | P Sawadh | B Nandapure | K Bharathi | G Markandeyulu | C Ramana | J B Nelson | D P Riley | M | Chaitanya Varma | S Mazenn | Abu-Elsaada | Khadour | N Raghuram | T Subba | K Rao | Babu Chandra | Naidu | T Rao | K Chandra | Babu Naidu | C Shivakumara | M Popov | O Fedorchuk | S Solopan | I Zavislyak | A Belous | O Lemine | B Vara Prasad | K Ramesh | D Chandra Sekhar
Source: Biointerface Research in Applied Chemistry (article, 2020-09-01)
Field: Materials Science — Materials Chemistry

X-Ray Diffraction and Magnetic Properties of Nd Substituted NiZnFe2O4 Characterized by Rietveld Refinement Solid-state method developed neodymium-doped Ni-Zn ferrites exhibit additional orthoferrite and α-Fe2O3 phases. The change in magnetic properties and lattice parameters are influenced by above mentioned extra phases other than the Nickel-Zinc ferrite spinel structure. Observations indicate that curie temperature, as well as saturation magnetization, reduce with an increase in Neodymium concentration. At the same time, for Nd = 0.02, initial permeability has been slightly increased. This paper explains the reason for these changes in terms of diluted octahedral sites replaced with Nd ions instead of Fe-ions and the number of additional phases that are present. Neodymium ; Spinel ; Materials science ; Orthoferrite ; Rietveld refinement ; Curie temperature ; Ion ; Ferrite (magnet) ; Magnetization ; Diffraction ; Saturation (graph theory) ; Analytical Chemistry (journal) ; Crystallography ; Ferromagnetism ; Chemistry ; Condensed matter physics ; Crystal structure ; Metallurgy ; Magnetic field ; Optics ; Physics Magnetic Properties and Synthesis of Ferrites ; Magnetic Properties and Applications ; Microstructure and Mechanical Properties of Steels
Authors: M. A. Ali | M. N. I. Khan | M. M. Hossain | F.-U.-Z. Chowdhury | M. N. Hossain | Rimi Rashid | M. A. Hakim | S. Manjura Hoque | M. M. Uddin
Source: arXiv (Cornell University) (preprint, 2020-01-21)
Field: Materials Science — Materials Chemistry

Mechanical behavior, enhanced dc resistivity, energy band gap and high temperature magnetic properties of Y-substituted Mg-Zn ferrites We report the synthesis of Y-substituted Mg-Zn ferrites using conventional standard ceramic technique. XRD patterns confirm the single phase cubic spinel structure up to x = 0.03 and appearance of a secondary phase of YFeO3for higher Y contents. FESEM images depict the distribution of grains and EDS spectra confirmed the absence of any unwanted element. Completion of solid state reaction and formation of spinel structure has been revealed from FTIR spectra. The FTIR data along with lattice constant, bulk density and porosity were further used to calculate the stiffness constant (Cij), elastic constant and Debye temperatures. Mechanical stability of all studied compositions is confirmed from Cij using Born stability conditions. Brittleness and isotropic nature are also confirmed using Poisson ratio and anisotropy constants, respectively. The enhancement of dc electrical resistivity with Y content is observed. The energy band gap (increased with Y contents) is found in good agreement with dc electrical resistivity. Ferrimagnetic to paramagnetic phase change has been observed from the field dependent high temperature magnetization curves. The magnetic moments and saturation magnetization were found to be decreased with increasing temperature. The Curie temperature (Tc) has been measured from temperature dependent magnetic moment (M-T) and initial permeability and found to be in good agreement with each other. Decrease in Tc with Y content is due to redistribution of cations and weakening of the exchange coupling constant. The magnetic phase transition has been analyzed by Arrott plot and found to have second order phase transition. The dc resistivity endorses the prepared ferrites are suitable for high frequency and high temperature magnetic device applications as well. Ferrimagnetism ; Materials science ; Electrical resistivity and conductivity ; Condensed matter physics ; Magnetization ; Curie temperature ; Debye model ; Analytical Chemistry (journal) ; Lattice constant ; Spinel ; Paramagnetism ; Ferromagnetism ; Chemistry ; Magnetic field ; Metallurgy Magnetic Properties and Synthesis of Ferrites ; Multiferroics and related materials ; Iron oxide chemistry and applications
Authors: P. Wilson
Source: International Journal for Research in Applied Science and Engineering Technology (article, 2020-12-28)
Field: Materials Science — Materials Chemistry

Green Synthesis of Silver Nano Particles using Ageratina Adenophora Leaf Extract In recent years, the green synthesis of silver nanoparticles using various plant extracts has attracted great attention. This is because these methods are simple, inexpensive, environment benign, nontoxic and large scale up process. Green synthesis method of nanoparticles is evolution from the Nano biotechnology. Development of green nanotechnology is generating interest of researches toward eco-friendly biosynthesis of nanoparticles. In this study, it was observed that silver ions were reduced by Ageratina adenophora leaf extract by refluxing method around 2 hours until leading to the formation of crystalline silver nanoparticles. A.adenophora is known as Crofton weed or sticky snakeroot, Mexican devil, eupatory, eupatorium adenophorum is a synonym. The green synthesized AgNPs were characterized using physical-chemical techniques viz., (UV-Vis) ultraviolet-visible spectroscopy, (XRD) X-ray diffraction, (SEM) scanning electron microscope coupled with (EDX) X-ray energy dispersive spectroscopy and (FTIR) Fourier transform-infrared spectroscopy. Silver Nano ; Nano- ; Materials science ; Nanotechnology ; Composite material Nanoparticles: synthesis and applications
Authors: Min Zhong
Source: Scientific Reports (article, 2020-11-16)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Design and verify a dual modulated metasurface in terahertz range A single peak tunable metasurface absorber is proposed and verified in Terahertz (THz) range. This absorption peak is excited by the localized surface plasma (LSP) and dielectric loss modes at resonance frequency 2.98 THz with 83% of amplitude. Three groups of experiments are performed to verify the sensing properties of samples. In the first groups of experiments, temperature is increasing from T = 300 k to T = 400 k, which leads to the absorption peak enhance from 83% (at 2.98 THz) to 93.7% (at 3.5 THz). In the second groups of experiments, samples are covered by ethanol or chloroform (T = 300 k), this absorption peak is also increased and moved to higher frequencies. When temperature and liquid layer are changed simultaneously, samples achieve more intense resonance behaviors in a smaller temperature scale. Finally, this absorption peak is reduced by increasing pump fluence. This proposed tunable metasurface absorber reveals the feasibility of sensing field. Terahertz radiation ; Materials science ; Absorption (acoustics) ; Resonance (particle physics) ; Optoelectronics ; Dielectric ; Fluence ; Excited state ; Amplitude ; Permittivity ; Optics ; Atomic physics ; Physics Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Antenna Design and Analysis