jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Tonghao Shen | Igor Ying Zhang | Matthias Scheffler
Source: arXiv (Cornell University) (preprint, 2018-10-18)
Field: Chemistry — Spectroscopy

Massive-parallel Implementation of the Resolution-of-Identity Coupled-cluster Approaches in the Numeric Atom-centered Orbital Framework for Molecular Systems We present a massive-parallel implementation of the resolution-of-identity (RI) coupled-cluster approach that includes single, double and perturbatively triple excitations, namely RI-CCSD(T), in the FHI-aims package for molecular systems. A domain-based distributed-memory algorithm in the MPI/OpenMP hybrid framework has been designed to effectively utilize the memory bandwidth and significantly minimize the interconnect communication, particularly for the tensor contraction in the evaluation of the particle-particle ladder term. Our implementation features a rigorous avoidance of the on-the-fly disk storage and an excellent strong scaling up to 10,000 and more cores. Taking a set of molecules with different sizes, we demonstrate that the parallel performance of our CCSD(T) code is competitive with the CC implementations in state-of-the-art high-performance computing (HPC) computational chemistry packages. We also demonstrate that the numerical error due to the use of RI approximation in our RI-CCSD(T) is negligibly small. Together with the correlation-consistent numeric atom-centered orbital (NAO) basis sets, NAO-VCC-nZ, the method is applied to produce accurate theoretical reference data for 22 bio-oriented weak interactions (S22), 11 conformational energies of gaseous cysteine conformers (CYCONF), and 32 isomerization energies (ISO32). Coupled cluster ; Computer science ; Benchmark (surveying) ; Computational science ; Parallel computing ; Physics ; Molecule ; Quantum mechanics Advanced NMR Techniques and Applications ; Advanced Chemical Physics Studies ; Machine Learning in Materials Science
Authors: Khalid Rashid, Alvina Rafiq Butt, MunirAhmad
Source: International Journal of Biosciences (IJB) (article, 2018-10-01)
Field: Materials Science — Biomaterials

Kinetics and Mechanism of the Adsorption of water-soluble anticancer drug on iron oxide nanoparticles doped with ferromagnetic materials Pure and doped iron oxide as spherical nanocarriers for the anticancer drug was synthesized using simple and cost-effective co-precipitation technique. A variety of techniques as XRD- x-ray diffraction, EDX-energy dispersive x-ray spectroscopy, UV-Vis-ultraviolet visible spectroscopy, SEM- scanning electron microscope and TEM- transmission electron microscope were employed to the prepared ferromagnetic metal oxide- (Fe3O4) and Co and Ni doped ferromagnetic materials to check their structural, compositional and morphological properties. These metaloxides nanocarriers were incorporated with ananti-cancer marker (doxorubicin) and loading capabilities were observed. The observed data was analyzed on different kinetics models. It was found that the drug loading capability of Cobalt doped Fe3O4 nanocarriers is higher relative to other carriers observed data was matched exactly with Lagergren Pseudo-first-order, Pseudo-second-order, Elovich equation and Intra-particle diffusion models. Nanocarriers ; Transmission electron microscopy ; Kinetics ; Ferromagnetism ; Scanning electron microscope ; Iron oxide ; Oxide ; Doping ; Adsorption Nanoparticle-Based Drug Delivery ; Magnetic Properties and Synthesis of Ferrites ; Chemical and Physical Properties of Materials
Authors: Yue Song
Source:  (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

The adsorption of amoxicillin by mesoporous silica supported polymers The emerging pollutants (EPs) originated from our fast developing modern society possess potential threat to human health and environment. Among many sources of EPs, regular as well as abusive use of antibiotics such as amoxicillin (AMX) has gained more attentions in recent years. However, corresponding treatment plan toward EPs is still in its infancy. On the other hand, novel nanomaterial (mesoporous silica supported polymers), which possess large surface area and amendable surface characteristics, can be used as adsorbent to remove EPs such as AMX. In this study, mesoporous silica supported polymers (H+-PANI/SBA-15 and PANI/SBA-15) were synthesized and demonstrated to adsorb AMX from solutions with different initial pH values and initial concentrations. Data were collected through UV-Vis spectrometer and pH meter. The material suitable for adsorbing AMX was found to be H+-PANI/SBA-15 under initial pH around 11.0 and with final pH around 7.0. The experimental adsorption data were modelled using pseudo-second order and intraparticle diffusion models and adsorption mechanisms were discussed as well. Adsorption ; Polymer ; Mesoporous material ; Mesoporous silica ; Materials science ; Chemistry ; Organic chemistry ; Catalysis ; Composite material Mesoporous Materials and Catalysis ; Nanoparticle-Based Drug Delivery ; Antibiotics Pharmacokinetics and Efficacy
Authors: Oluwatobiloba A Akinwande
Source: EngagedScholarship @ Cleveland State University (Cleveland State University) (article, 2018-01-01)
Field: Chemistry — Analytical Chemistry

Color Removal from Combined Dye and Fruit Nectar Wastewater Using Adsorption and Microfiltration Pollution of the waterways is a great challenge of the 21st century.Textile effluents contain compounds which have the capacity to cause more harm when ingested.There are many dye removal technologies like coagulation, photo oxidation which help to remove color from dye wastewater.The use of adsorption to remove color from dye wastewater has been used for many centuries.Activated carbon can efficiently remove color from dye wastewater but it is very expensive and so different researches have been conducted to get the adsorption capacity of different forms of adsorbents.These adsorbents can be gotten from agricultural waste, biomass, and industrial waste and even household materials like paper.In this research, agricultural adsorbents like orange peel, banana peel and onion peel are being used as adsorbents to treat dyes like Acid red 88, Direct blue 15 and Rhodamine 6G.The amount of adsorbent dose and dye concentration is being varied to know at what dye concentration or adsorbent dose effectively removes color from dye wastewater.In this study, the treatment of a binary mixture of dye wastewater with fruit drink of different concentrations, low (10ppm), medium (50ppm) and high (100ppm).The dye waste water was prepared in the laboratory while the fruit drink was bought from a local grocery store.Color removal efficiency was investigated for the three adsorbents; orange vii peel, banana peel, onion peel.Transmittance and Absorbance values were used to determine the removal efficiency of the adsorption process Microfiltration ; Wastewater ; Adsorption ; Pulp and paper industry ; Environmental science ; Chemistry ; Nectar ; Chromatography ; Waste management ; Botany ; Environmental engineering ; Biology ; Membrane ; Engineering ; Organic chemistry ; Biochemistry ; Pollen Dye analysis and toxicity ; Adsorption and biosorption for pollutant removal ; Water Quality Monitoring and Analysis
Authors: Hongmei Tang | Wenyao Li | Haishun Jiang | Runjia Lin | Zhe Wang | Jianghong Wu | Guanjie He | Paul R. Shearing | Dan J. L. Brett
Source: Preprints.org (preprint, 2018-12-28)
Field: Materials Science — Materials Chemistry

ZIF-8 Derived Hollow Carbon for Efficient Adsorption of Antibiotics The harmful nature of high concentrations of antibiotics to humans and animals requires urgent development of novel materials and techniques for their absorption. In this work, CTAB (Cetyltrimethyl Ammonium Bromide)-assisted synthesis of ZIF-8 (zeolitic imidazolate framework) derived hollow carbon (ZHC) was designed, prepared and used as a high-performance adsorbent, further evaluated by Langmuir and Freundlich isothermal adsorption experiments, dynamic analysis as well as theoretical calculation. The maximum capacities of ZHC on adsorbing tetracycline (TC), norfloxacin (NFO) and levofloxacin (OFO) are 267.3, 125.6 and 227.8 mg g-1, respectively, which delivers superior adsorptive performance when compared to widely studied inorganic adsorbates. The design concept of ZIFs-derived hollow carbon material provides guidance and insights for the efficient adsorbent of environmental antibiotics. Adsorption ; Ammonium bromide ; Langmuir ; Freundlich equation ; Zeolitic imidazolate framework ; Chemistry ; Chemical engineering ; Absorption (acoustics) ; Carbon fibers ; Tetracycline ; Nuclear chemistry ; Materials science ; Antibiotics ; Organic chemistry ; Metal-organic framework ; Pulmonary surfactant ; Composite number ; Composite material ; Biochemistry Boron and Carbon Nanomaterials Research ; Adsorption and biosorption for pollutant removal ; Covalent Organic Framework Applications
Authors: Abdurrahman Helal Ahmed Dhananjay Patil
Source: Zenodo (CERN European Organization for Nuclear Research) (article, 2018-08-24)
Field: Materials Science — Polymers and Plastics

Formulation, Development And In Vitro Evaluation Of Sildenafil Citrate Lignocaine Hcl Gel <em>The present study was undertaken to formulate, development and in vitro evaluation</em> <em>of Sildenafil Lignocaine gel</em>. <em>Sildenafil citrate is a drug of choice used in the treatment of premature ejaculation disorder</em>. <em>Topical gel has gained more and more importance because the gel based formulations are better percutaneously absorbed than creams and ointment bases</em>. <em>Therefore, topical gel of Sildenafil citrate was prepared using polymer of Carbopol 934 and triethanolamine at different proportions</em>. <em>The study encompasses compatibility studies using FTIR spectra, drug content, viscosity, spreadability, and pH determination</em>. <em>Further the optimized formulation F5 was evaluated by in vitro diffusion study</em>. <em>Optimized formulation batch F5 subjected to stability as well as in vitro study</em>. <em>The preliminary compatibility studies conducted revealed that there was no interaction between Sildenafil citrate and excipients</em>. <em>In vitro drug release study was carried out with Franz diffusion cell using egg membrane in pH 7</em>.<em>4 phosphate buffers as diffusion medium</em>. <em>Formulation batch F5 containing Carbopol 934 and triethanolamine showed 99</em>.<em>09</em> % <em>drug release at 60 min and 5</em>.<em>55 g</em>.<em>cm </em>/<em>sec spreadability</em>. <em>Result showed that formulation batch F5 showed better drug release at one h</em>. <em>Formulation batch F5 was used further for stability and ex vivo study</em>. <em>Stability studies conducted under accelerated condition were shown satisfactory results</em>. <em>It was concluded that Carbopol gel containing Sildenafil citrate showed good consistency, spreadability, homogeneity and stability</em>. <em>So, topical gel had wider prospect for topical preparations</em>. <strong>Keywords:</strong> <em>Sildenafil citrate, Carbopol 934, Triethanolamine,</em> <em>Topical gel of Sildenafil citrate</em>. Sildenafil ; In vitro ; Chemistry ; Pharmacology ; Chromatography ; Anesthesia ; Medicine ; Biochemistry ; Internal medicine Synthesis and properties of polymers ; Chemical Thermodynamics and Molecular Structure
Authors: Mirjana Dimitrievska | Jean‐Noël Chotard | Raphaël Janot | Antonio Faraone | Wan Si Tang | A.V. Skripov | Terrence J. Udovic
Source: The Journal of Physical Chemistry C (article, 2018-10-01)
Field: Materials Science — Materials Chemistry

Tracking the Progression of Anion Reorientational Behavior between α-Phase and β-Phase Alkali-Metal Silanides, MSiH<sub>3</sub>, by Quasielastic Neutron Scattering Quasielastic neutron scattering (QENS) measurements over a wide range of energy resolutions were used to probe the reorientational behavior of the pyramidal SiH<sub>3</sub> <sup>-</sup> anions in the monoalkali silanides (MSiH<sub>3</sub>, where M = K, Rb, and Cs) within the low-temperature ordered <i>β</i>-phases, and for CsSiH<sub>3</sub>, the high-temperature disordered <i>α</i>-phase and intervening hysteretic transition region. Maximum jump frequencies of the <i>β</i>-phase anions near the <i>β</i>-<i>α</i> transitions range from around 10<sup>9</sup> s<sup>-1</sup> for <i>β</i>-KSiH<sub>3</sub> to 10<sup>10</sup> s<sup>-1</sup> and higher for <i>β</i>-RbSiH<sub>3</sub> and <i>β</i>-CsSiH<sub>3</sub>. The <i>β</i>-phase anions undergo uniaxial 3-fold rotational jumps around the anion quasi-<i>C</i> <sub>3</sub> symmetry axis. CsSiH<sub>3</sub> was the focus of further studies to map out the evolving anion dynamical behavior at temperatures above the <i>β</i>-phase region. As in <i>α</i>-KSiH<sub>3</sub> and <i>α</i>-RbSiH<sub>3</sub>, the highly mobile anions (with reorientational jump frequencies approaching and exceeding 10<sup>12</sup> s<sup>-1</sup>) in the disordered <i>α</i>-CsSiH<sub>3</sub> are all adequately modeled by H jumps between 24 different locations distributed radially around the anion center of gravity, although even higher anion reorientational disorder cannot be ruled out. QENS data for CsSiH<sub>3</sub> in the transition region between the <i>α</i>- and <i>β</i>-phases corroborated the presence of dynamically distinct intermediate (<i>i</i>-) phase. The SiH<sub>3</sub> <sup>-</sup> anions within <i>i</i>-phase appear to undergo uniaxial small-angular-jump reorientations that are more akin to the lower-dimensional <i>β</i>-phase anion motions rather than to the multidimensional <i>α</i>-phase anion motions. Moreover, they possess orientational mobilities that are an order-of-magnitude lower than those for <i>α</i>-phase anions but also an order-of-magnitude higher than those for <i>β</i>-phase anions. Combined QENS and neutron powder diffraction results strongly suggest that this <i>i</i>-phase is associated chiefly with the more short-range-ordered, nanocrystalline portions (invisible to diffraction) that appear to dominate the CsSiH<sub>3</sub>. Ion ; Quasielastic neutron scattering ; Phase (matter) ; Chemistry ; Phase transition ; Neutron scattering ; Quasielastic scattering ; Scattering ; Molecular physics ; Chemical physics ; Crystallography ; Condensed matter physics ; Inelastic neutron scattering ; Physics ; Optics Hydrogen Storage and Materials ; High-pressure geophysics and materials ; Superconductivity in MgB2 and Alloys
Authors: S Mei | J Xie | X Chen | F He | H Yang | H Mikulcic | E Berg | M Vujanovic | X Wang | H Tan | R Havryliv | V Maystruk | V Biliak | R Zarzycki | R Kobylecki | M Kratofil | Y Zhao | T Sun | B Sun | J Elder | V Ready | V Georgieva | L Vlaev | K Gyurova | C Rodriguez-Navarro | E Ruiz-Agudo | A Luque | A Rodriguez-Navarro | M Ortega-Huertas | A Galwey | M Brown | S Vyazovkin | T Prasad | S Kanungo | H Ray | K Ninan | K Krishnan | V Krishnamurthy | A Khawam | D Flanagan | D Dollimore | P Tong | K Alexander | C Haixiang | L Naian | Z Weitao | M Jin | N Duic | Z Bis
Source: Voprosy Khimii i Khimicheskoi Tekhnologii (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

Kinetic analysis of thermal decomposition of finely dispersed limestone wastes for the development of a numerical simulation model On the basis of the analysis of known literature data on CaCO 3 thermal decomposition, it is concluded that the development of a compact engineering CFD model (computational fluid dynamics) for limestone calcination is a topical issue.This model can be based on thermogravimetric data and standard mathematical approximation algorithms.Experiments on thermal decomposition of finely dispersed limestone waste particles of different fractions less than 315 m were carried out using a Q-1500 D derivatograph (system F. Paulik, J. Paulik and L. Erdey) under non-isothermal conditions.Based on differential equations of topochemical solid-state kinetics and the asymmetry of differential thermogravimetry (DTG) curves, the values of activation energy, pre-exponential factor in Arrhenius equation were calculated and the reaction mechanism of the thermal decomposition of particles was determined from the results of non-isothermal experiments performed at the heating rate of 10 0 C/min in a temperature range of 600 to 900 0 C. A new engineering approach was developed to the CFD simulation of the thermal decomposition of limestone wastes by means of a two-step mechanism of solid-state kinetics using commercial CFD code ANSYS Fluent.The findings could be used in chemical engineering to produce new highly efficient equipment. Thermal decomposition ; Decomposition ; Thermal ; Computer simulation ; Kinetic energy ; Materials science ; Thermal analysis ; Mineralogy ; Chemical engineering ; Environmental science ; Thermodynamics ; Chemistry ; Engineering ; Simulation ; Physics Thermal and Kinetic Analysis ; Energetic Materials and Combustion ; Zeolite Catalysis and Synthesis
Authors: S. V. Natareev | D. E. Zakharov | Aleksey A. Sirotkin | S. V. Belyaev
Source: IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA (article, 2018-12-30)
Field: Materials Science — General Materials Science

ION EXCHANGE ON A FIBROUS ION EXCHANGER IN A FLO-TYPE CAPACITIVE APPARATUS The objective of this study is to elaborate the analytical theory of ion exchange in the field of solving the boundary value problems of non steady state mass transfer in solids with a canonical form taking into account a change in the concentration of the solution and the character of movement of the phases in a flow apparatus. The mathematical description of the process of ion-exchange solution purification on ionite particles of cylindrical shape in a batch flow apparatus was developed. At the developing mathematical description the following assumptions were used: the ionite is monodisperse, uniform initial distribution of substances in the ionite, the ion exchange equilibrium is described by Henry equation, the rate of the process is limited by both internal and external diffusion, the flow pattern of the liquid phase in the apparatus is described by the perfect mixing model, the solution with the constant volumetric flow rate and the constant concentration of the substance is supplied to the apparatus, kinetic and hydrodynamic process parameters are constants. Mathematical description includes the following equations: the diffusion equation of ionite, isotherm equation ion exchange, the equation for average concentration of the substance in the ionite, the material balance equation for a perfect mixing flow apparatus, initial and boundary conditions. To solve boundary value problem, we use the integral Laplace transformations. The obtained equation allows to analyze the effect of the volumetric flow rate of the solution supplied to a flow apparatus, the ratio of the volumes of solid and liquid phases in the apparatus, the diameter of the particle, and other parameters of the process on the concentration distribution of a substance along the internal coordinate of the solid. The developed mathematical model is used to study the desorption of copper ions from the modified polycaproamide fiber with sulfuric acid solution. Chemistry ; Boundary value problem ; Thermodynamics ; Diffusion equation ; Diffusion ; Mass transfer ; Flow (mathematics) ; Ion exchange ; Mechanics ; Ion ; Physics ; Mathematics ; Mathematical analysis ; Chromatography Material Properties and Applications
Authors: Mohammad Mehdi Forouzan
Source: ScholarsArchive  (Brigham Young University) (article, 2018-01-01)
Field: Materials Science — Polymers and Plastics

Simulation and Experiments to Understand the Manufacturing Process, Microstructure and Transport Properties of Porous Electrodes Battery technology is a great candidate for energy storage applications. The need for high-performance and cost-effective batteries has motivated researchers to put much effort into improving battery performance. In this work, we attempt to understand the elements that affect the microstructure and performance of two battery systems. The first part of this work focuses on the investigation of transport and structural properties of porous electrodes in an alkaline electrolyte. A DC polarization method was deployed for tortuosity measurements. An apparatus was designed to flow specified current through and measure the voltage drop over the porous electrodes. Using a modified Ohm's law, effective diffusion coefficient and associated tortuosity were determined. Multiple compositions (different types and amounts of conductive additives) were tested to understand the effects of composition on the transport properties. As a validation and to further understand the tests, a model was developed and used for data analysis. The second part of this dissertation describes simulations of the manufacturing process of a Li-ion electrode. LAMMPS, a particle simulator, was used for this meso-scale particle-based simulation. The interactions between particles were understood by model-experiment comparisons of the macroscopic properties such as viscosity of the slurry and elasticity of the dried film. The microstructure created by this simulation was consistent with the one we observed in SEM/ FIB images. Although the emphasis was the drying process in this part, some preliminary coating and calendering simulations are presented. Finally, the effects of electrode heterogeneity were investigated by a Newman-type model and tomographic images. An electronic conductivity map was initially generated over a Li-ion cathode. Then SEM/FIB images of specified high, middle, and low conductivity regions were taken to confirm heterogeneity. For modeling purposes, three regions of high, middle, and low ionic resistance were considered connected in parallel, representing the real electrode heterogeneity. Multiple cases of heterogeneities such as non-uniform ionic resistance and active material loading at low, middle, and high charge-discharge rates were studied. The results show that higher rates increase non-uniformities of dependent properties such as temperature, current density, positive and negative electrodes states of charge, and charge and discharge capacities especially in charging cases. Microstructure ; Porosity ; Process (computing) ; Materials science ; Electrode ; Metallurgy ; Computer science ; Composite material ; Chemistry Conducting polymers and applications ; Fuel Cells and Related Materials
Authors: Jonathon N. Baker
Source: NCSU Libraries Repository (North Carolina State University Libraries) (article, 2018-06-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Point Defects in Strontium and Barium Titanate from First Principles: Properties and Thermodynamics. BAKER, JONATHON NEAL Strontium ; Thermodynamics ; Barium ; Strontium titanate ; Materials science ; Chemistry ; Mineralogy ; Physics ; Inorganic chemistry ; Nanotechnology ; Thin film Magnetic and transport properties of perovskites and related materials ; Inorganic Chemistry and Materials ; Electronic and Structural Properties of Oxides