jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: A. Djato | Marianne Béringhier | Marco Gigliotti
Source: Mechanics of Materials (article, 2019-12-14)
Field: Materials Science — General Materials Science

On the identification of diffuso-mechanical properties of polymer matrix materials based on the use of plates with asymmetric moisture concentration field Materials science ; Moisture ; Identification (biology) ; Matrix (chemical analysis) ; Field (mathematics) ; Composite material ; Polymer ; Mathematics Material Properties and Applications ; Mechanical and Thermal Properties Analysis ; Advanced Theoretical and Applied Studies in Material Sciences and Geometry
Authors: Osami Yamamoto | Yuichi Matsuo | Shinichi Tosa | Tatsuya Okayama | Zhiwei Zhang | John Tolsma
Source: SAE technical papers on CD-ROM/SAE technical paper series (article, 2019-04-02)
Field: Materials Science — Materials Chemistry

Numerical Modeling Study of Detailed Gas Diffusivity into Catalyst Washcoat for Lean NOx Catalyst &lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;To evaluate the relationship between the exhaust gas purification performance and the catalyst pore properties related to gas diffusion, an elementary reaction model was combined with gas diffusion into catalyst pores, referred to as the pseudo-2D gas diffusion/reaction model. It was constructed for Pt/Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; + CeO&lt;sub&gt;2&lt;/sub&gt; catalyst as lean NOx catalyst. The gas diffusion was described as macro pore diffusion between the catalyst particles and meso pore diffusion within the particle. The kinetic model was composed of 26 reactions of NO/CO/O&lt;sub&gt;2&lt;/sub&gt; chemistry including 17 Pt/Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; catalyst reactions and 9 CeO&lt;sub&gt;2&lt;/sub&gt; reactions. Arrhenius parameters were optimized using activity measurement results from various catalysts with various pore properties, meso pore volume and diameter, macro pore volume and diameter, particle size, and washcoat thickness. Good agreement was achieved between the measured and calculated values. Moreover, as compared to the performance of other catalysts which was not used for reaction model calibration, the simulated results were in good agreement with this experimental data. Using the calibrated reaction model combined with detailed gas diffusion model, a sensitivity analysis for NOx concentration was performed to identify key diffusion parameters of the lean NOx catalyst. In summary, parameters with the highest sensitivity were catalyst particle size, washcoat thickness, CeO&lt;sub&gt;2&lt;/sub&gt; meso pore volume, and diameter. Also, catalyst macro pore volume and diameter showed no dependence. Consequently, to increase the NOx purification performance, the meso pore parameters and washcoat thickness should be increased, particle size should be decreased. With these changes, the gaseous NOx will easily move to the catalyst surface and into the active site of meso pore, resulting in better performance.&lt;/div&gt;&lt;/div&gt; NOx ; Catalysis ; Thermal diffusivity ; Chemical engineering ; Materials science ; Process engineering ; Computer science ; Automotive engineering ; Environmental science ; Combustion ; Engineering ; Thermodynamics ; Chemistry ; Physics ; Physical chemistry ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Industrial Gas Emission Control
Authors: L. M. Soldatkina | T. V. Tiutiunnyk | V. V. Menchuk | А. П. Поликарпов | V. O. Novotna
Source: Odesa National University Herald Chemistry (article, 2019-03-04)
Field: Chemistry — Analytical Chemistry

KINETIC REGULARITIES OF ADSORPTION OF ANTHOCYANINS FROM EXTRACTS OF CHOCKEBERRY AND ELDERBERRY ON CATIONIC EXCHANGER FIBAN K-1 This study describes kinetic regularities of anthocyanin adsorption from chokeberry and elderberry extracts on fibrous strong acid cationic exchanger FIBAN K-1 in a batch mode. Extracts of chokeberry and elderberry were prepared by maceration of crushed berries in 0.1 M HCl. The effect of various parameters like initial anthocyanin concentration (100-250 mg/L), temperature (20-50 oC), pH (2.0-3.5), and cationic exchanger mass (4.5-9.0 g/L) on kinetics of anthocyanin adsorption was investigated. Increasing of the initial anthocyanin concentration from 100 to 250 mg/L increases equilibrium anthocyanin adsorption ~ in 2.5 times from chokeberry extracts and ~ in 2 times from elderberry extracts. Equilibrium adsorption time of both types of the berries decreases from 135 to 75 min with increasing of temperature from 20 to 50 °C. Maximum values of equilibrium anthocyanin adsorption from chokeberry and elderberry extracts was observed at pH=2.0. Equilibrium adsorption of anthocyanins on cationic exchanger FIBAN K-1 decreases with increasing of its mass. Experimental kinetic curves of anthocyanin adsorption were modeled using four kinetic models. The adequacy of kinetic models was estimated using linear correlation coefficients (R2) and standard errors (SE). It was established, that kinetics results are better simulated by the kinetic models in the order: pseudo-second order &gt; Elovich &gt; intra-particle diffuse &gt; pseudo-first order. The experimental kinetic curves are fitted well to the pseudo-second order and Elovich models indicatting that adsorption process is limited by chemical reaction between anthocyanins as flavilium cations with SO3-functional groups of cationic exchanger. The simulation with the diffusion model has shown the adsorption process proceeds in the mixed diffusion regime. Anthocyanin ; Chemistry ; Adsorption ; Cationic polymerization ; Kinetics ; Chromatography ; Kinetic energy ; Organic chemistry ; Food science Chromatography in Natural Products ; Analytical Chemistry and Chromatography ; Freezing and Crystallization Processes
Authors: Zangue Henriette Adjia | Bùi Thị Nga Trần Thanh Nga | R. Kamga | Frédéric Villièras | Nko’o G. Ebio
Source: International Journal of Water Resources and Environmental Engineering (article, 2019-08-31)
Field: Materials Science — Biomaterials

Enhancing the adsorption of Pb(II) and Fe(II) in the reactor by the thermally treated alluvial clay from Far North Cameroon The objective of this work was to investigate the influence of the thermal treatment of alluvial clay on the ad-sorption capacity of Pb(II) and Fe(II) to reduce clogging during adsorption phenomenon. The chemical,&nbsp; X- ray&nbsp; diffraction&nbsp; (XRD),&nbsp; Fourier&nbsp; transform&nbsp; infrared&nbsp; spectroscopy&nbsp; (FTIR), &nbsp;scanning&nbsp; electron microscope (SEM) and transmission electron microscopy (TEM) analysis of the alluvial clays reveal that the&nbsp; main&nbsp; mineral&nbsp; present&nbsp; is&nbsp; smectite,&nbsp; kaolinite&nbsp; and&nbsp; quartz. Cation exchange&nbsp; capacity&nbsp; (CEC)&nbsp; and&nbsp; specific surface area of the raw clay fraction are 62 meq/100 g and 104 m2/g respectively. The&nbsp; mains&nbsp; oxydes&nbsp; of alluvial clay fraction&lt;50&micro;m are SiO2, Al2O3 and&nbsp; Fe2O3.The adsorbent used in this work is the alluvial clay, that after splitting has been thermally treated at 300&deg;C and 600&deg;C, the natural clay properties does not completely disappear until 300&deg;C and 600&deg;C. This study shows that the losses are about 3% for the heat treatment at 300&deg;C (A300) and 5% for the heat treatment at 600&deg;C (A600) after fractionation of Alluvial clays. The adsorption equilibrium is reached in five minutes, whatever the pH, temperature and the molar ratio of the solution. The pH is increased the removal increases as seen from plots of&nbsp; 2, 4 and 6 which gave removals as high as 92.15&mu;mol/g and 100.6 &mu;mol/g to Pb(II) and 92.68 &mu;mol/g and 110.5 &mu;mol/g to Fe(II) respectively. The temperature is decreased the removal increases as seen from plots of&nbsp; 50&deg;C, 40&deg;C and 30&deg;C which gave removals as high as 99.8 &mu;mol/g and 100.3 &mu;mol/g to Pb(II) and 98.9 &mu;mol/g and 100.3 &mu;mol/g to Fe(II) respectively. While, the adsorption capacity was increased as decreasing the temperature. So, it is be recognized that adsorption mechanism should be physical adsorption. The adsorption process of Pb(II) and Fe(II) are best described by the second-order equation. However, the adsorption isotherms could be well fitted by the Freundlich equation, proves the surface heterogeneity of thermally treated Alluvial Clay.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Key words: Adsorption, agitated reactor, thermally treated alluvial clay, Cameroon. &nbsp; Kaolinite ; Adsorption ; Clay minerals ; Sorption ; Fourier transform infrared spectroscopy ; Nuclear chemistry ; Chemistry ; Cation-exchange capacity ; Mineralogy ; Materials science ; Chemical engineering ; Geology ; Soil water ; Organic chemistry Clay minerals and soil interactions ; Adsorption and biosorption for pollutant removal ; Geochemistry and Geologic Mapping
Authors: B. Cimen | Sonya ŞENGÜL | Memduha Ergüt | Ayla Özer
Source: Sinop Üniversitesi Fen Bilimleri Dergisi (article, 2019-06-27)
Field: Materials Science — Materials Chemistry

CuO Nanopartiküllerinin Yeşil Sentezi ve Karakterizasyonu: Telon Blue AGLF ve Metilen Mavisi Adsorpsiyonu In this study, CuO nanoparticles (CuONPs) were synthesized using Acacia cyanophylla leaves aqueous extract as a non-toxic, easily available and cost-effective reducing agent. The green synthesized CuONPs were characterized by SEM/EDX, DLS, FT-IR and XRD analysis. Subsequently, Telon Blue AGLF (TB AGLF) and Methylene Blue (MB) adsorption onto the CuONPs were carried out and optimum adsorption conditions were investigated. Optimum conditions were determined as initial pH 7 and 8, temperature 25°C and adsorbent concentration 1 g/L for TB AGLF and MB, respectively. Also; a linear increase was observed in adsorbed dye amounts with increasing both initial dye concentrations. Experimental equilibrium data better fitted to the Langmuir and Freundlich isotherm models for TB AGLF and MB, respectively. The calculated free energy values from D-R isotherm model, were lower than 8 kJ/mol which was indicating that the both adsorption processes proceeded through physisorption. The adsorption kinetics of TB AGLF and MB onto CuONPs show the better suitability of pseudo-second-order kinetic model; and, Weber-Morris intraparticle diffusion model showed that, not only intraparticle both also film diffusion resistances were influential in the adsorption processes. Adsorption ; Methylene blue ; Physisorption ; Freundlich equation ; Diffusion ; Nuclear chemistry ; Chemistry ; Aqueous solution ; Langmuir ; Langmuir adsorption model ; Activation energy ; Analytical Chemistry (journal) ; Chromatography ; Organic chemistry ; Catalysis ; Thermodynamics Copper-based nanomaterials and applications ; Laser-Ablation Synthesis of Nanoparticles ; Nanomaterials for catalytic reactions
Authors: S. I. Bozhko | Killian Walshe | N. A. Tulina | Brian Walls | Olaf Lübben | Barry E. Murphy | Vladimir Bozhko | I. V. Shvets
Source: Scientific Reports (article, 2019-04-17)
Field: Materials Science — Materials Chemistry

Surface modification on MoO2+x/Mo(110) induced by a local electric potential Oxygen adatoms on the MoO<sub>2+x</sub>/Mo(110) surface are observed to be removed when a sufficiently large bias is applied between the scanning tunneling microscope tip and the surface. Experimental observations, such as the bias polarity dependence of adatom removal and the observation of an intermediate state, indicate that the adatom penetrates the surface oxide layer. Through the comparison of finite element method simulations with various experimental relationships, the electric field is concluded to be the sole contributor to adatom penetration into the surface oxide layer. The energetic barrier to this process is estimated to be approximately 0.45 eV in magnitude. Furthermore, the resolution of this phenomenon is on the atomic scale: individual adatoms can undergo surface penetration whilst their nearest neighbour adatoms, separated by 5 Å, are unaffected. The mechanism reported here has the advantages of not strongly influencing the substrate and is exceptionally localised, which can be beneficial for the synthesis of single atom devices. Scanning tunneling microscope ; Penetration (warfare) ; Electric field ; Oxide ; Chemical physics ; Materials science ; Penetration depth ; Atomic units ; Molecular physics ; Quantum tunnelling ; Condensed matter physics ; Atomic physics ; Nanotechnology ; Chemistry ; Optoelectronics ; Optics ; Physics Electronic and Structural Properties of Oxides ; Semiconductor materials and devices ; Electrocatalysts for Energy Conversion
Authors: Ulf R. Pedersen
Source: The Journal of Chemical Physics (article, 2019-03-04)
Field: Materials Science — Materials Chemistry

Statistics of small length scale density fluctuations in supercooled viscous liquids Many successful theories of liquids near the melting temperature assume that small length scale density fluctuations follow Gaussian statistics. This paper presents a numerical investigation of density fluctuations in the supercooled viscous regime using an enhanced sampling method. Five model systems are investigated: the single component Lennard-Jones liquid, the Kob-Andersen binary mixture, the Wahnström binary mixture, the Lewis-Wahnström model of ortho-terphenyl, and the TIP4P/Ice model of water. The results show that the Gaussian approximation persists to a good degree into the supercooled viscous regime; however, it is less accurate at low temperatures. The analysis suggests that non-Gaussian fluctuations are related to crystalline configurations. Implications for theories of the glass transition are discussed. Supercooling ; Binary number ; Gaussian ; Scale (ratio) ; Length scale ; Glass transition ; Viscous liquid ; Component (thermodynamics) Material Dynamics and Properties ; Phase Equilibria and Thermodynamics ; Advanced Physical and Chemical Molecular Interactions
Authors: Nicholas E. Rothfuss
Source: NCSU Libraries Repository (North Carolina State University Libraries) (article, 2019-01-23)
Field: Materials Science — Materials Chemistry

Toward Better Characterization of the Viscosity of Organic Aerosol. Aerosol ; Viscosity ; Characterization (materials science) ; Environmental science ; Chemistry ; Materials science ; Nanotechnology ; Composite material ; Organic chemistry Catalytic Processes in Materials Science ; Gas Sensing Nanomaterials and Sensors ; Air Quality Monitoring and Forecasting
Authors: Enkhtur Otgonjargal | Kitae Baek | Jung‐Seok Yang | Enkhtuul Surenjav | Aruukhan Dashkhuu Khasbaatar
Source: Mongolian Journal of Chemistry (article, 2019-12-27)
Field: Materials Science — Materials Chemistry

Study on removal of Se(IV) using Fe-Mn layered double hydroxides and Fe-Mn Dos (double oxides) In this study, Fe-Mn-CO3 layered double hydroxide (LDHs) and Fe-Mn Double oxide (DOs) were synthesized by the co-recipitation methods for Se(IV) removal from aqueous solutions. The Se(IV) adsorption capacities and removal mechanism of Fe-Mn LDH and Fe-Mn DOs determined by batch and column experiments. The calculated Se(IV) adsorption capacities on Fe-Mn LDH and Fe-Mn DOs were 52.5 and 55.3 mg/g, respectively. Kinetic models applied to the adsorption of Se(IV) on the Fe-Mn LDH and Fe-Mn DOs calculated using pseudo-first, second-order, Elovich, and Intraparticle diffusion kinetic models and all kinetic parameters were calculated and discussed. Isotherm studies were also performed using Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich equations in the temperature range of 283 - 323 K. Adsorption kinetics and isotherm experiments are well fitted pseudo-second order model and Freundlich isotherm, respectively. The production of this adsorbent is cost-effective for industrial applications. Freundlich equation ; Layered double hydroxides ; Adsorption ; Hydroxide ; Chemistry ; Diffusion ; Langmuir ; Aqueous solution ; Kinetics ; Inorganic chemistry ; Oxide ; Kinetic energy ; Nuclear chemistry ; Physical chemistry ; Thermodynamics ; Organic chemistry Layered Double Hydroxides Synthesis and Applications ; Catalytic Processes in Materials Science ; Advanced Photocatalysis Techniques
Authors: Valeria Cuccia | SANDRO ROGÉRIO NOVAES SELES | Ana Cláudia Queiroz Ladeira
Source: Brazilian Journal of Radiation Sciences (article, 2019-06-18)
Field: Materials Science — Materials Chemistry

Removal of cobalt from lubricant oil by the use of bentonite: equilibrium, kinetic and adsorption preliminary studies Radionuclides may contaminate lubricant oils in nuclear power plants. In Brazil, this kind of waste has been stored in the generator’s facilities, awaiting treatment alternatives. This work intends to investigate a process to treat it for final deposition, using bentonite as sorbent material. This process will result in decontaminated oil, free from radiological control, and radioactive loaded sorbent, with considerable volume reduction of the radioactive waste. The study focuses in cobalt removal from a simulated oil waste (non-active). The production of the simulated waste is described. Benton-ite was used for equilibrium time determination, kinetic and adsorption studies. Cobalt adsorption equilibrium was rapidly attained after 30 minutes. The data was used for modelling the system’s kinetic, applying the pseudo first and pseudo second order equation models. Experimental data fitted to pseudo second order model, supporting the assump-tion that the adsorption is due to chemisorption. Batch sorption tests were conducted and the results fitted to Langmuir and Freundlich sorption models. Both isotherm models chosen for this work did not fit to the experimental data. Thus, these are preliminary results and the studies must be repeated to evaluate data variability and better statistical inference. Other isotherm models must be evaluated to choose the best fitted one and describe the sorption of cobalt on bentonite in oil matrix. Even though, bentonite has considerable potential as sorbent for the removal of cobalt from lubricant oil. Finally, the results might be extended to other kinds of radioactive oils and radioactive organic wastes. Sorption ; Sorbent ; Bentonite ; Adsorption ; Freundlich equation ; Cobalt ; Radioactive waste ; Lubricant ; Waste management ; Human decontamination ; Radionuclide ; Langmuir ; Chemistry ; Environmental science ; Materials science ; Chemical engineering ; Nuclear chemistry ; Organic chemistry ; Engineering Graphite, nuclear technology, radiation studies ; Radioactive element chemistry and processing ; Chemical Synthesis and Characterization
Authors: Thierno-Moussa Bah
Source: theses.fr (ABES) (preprint, 2019-07-03)
Field: Materials Science — Materials Chemistry

Development and characterization of a thermoelectric harvester demonstrator using phonon engineered silicon membranes L'essor de l'internet des objets (IoT) et des capteurs autonomes et communicants semble être retardé en raison du manque de source d’énergie fiable, sûre et à faible coût. Les récupérateurs d’énergies thermoélectriques présentent ces avantages clés. Le silicium présente les avantages d'être très abondant, moins polluant et de bénéficier d'installations et de procédés technologiques permettant la production en série de récupérateurs d’énergies thermoélectriques à faible coût par rapport aux matériaux conventionnel (alliages de tellure de bismuth). Toutefois, le silicium est un matériau thermoélectrique médiocre en raison de sa conductivité thermique élevée ( ). La possibilité de réduire la conductivité thermique tout en préservant la conductivité électrique et le coefficient Seebeck est la clé pour améliorer le silicium en tant que matériau thermoélectrique efficace. À cette fin, les efforts sont orientés vers la partie phononique du transport de chaleur, qui constitue la contribution dominante dans les semi-conducteurs. Les recherches menées au cours de cette thèse ont porté sur l'intégration des membranes de silicium nanostructurées de réseaux phononiques dans des démonstrateurs de récupérateurs d’énergies thermoélectriques et leur caractérisation au regard de l'état de l’art. Les résultats de ces études ont démontré la faisabilité d’un récupérateur d’énergie thermoélectrique à base de silicium présentant des performances (De quelques µW/cm2 pour ΔT~5-10K à quelques mW/cm2 pour ΔT>100K) suffisantes pour l’alimentation en énergie de nœuds de capteurs autonomes et des performances comparables à celles d’un récupérateur (état de l’art) à base de tellure de bismuth en fonction des conditions de refroidissement de ces derniers. De plus, cette thèse a démontré, outre la récupération d'énergie, la possibilité de développer des refroidisseurs thermoélectriques à base de silicium, ouvrant la voie à une possible intégration de refroidisseurs thermoélectriques dans des dispositifs micro-électroniques à base de silicium. Characterization (materials science) ; Thermoelectric effect ; Materials science ; Phonon ; Membrane ; Silicon ; Thermoelectric materials ; Nanotechnology ; Engineering ; Mechanical engineering ; Optoelectronics ; Composite material ; Condensed matter physics ; Physics ; Thermal conductivity ; Chemistry ; Quantum mechanics Advanced Thermoelectric Materials and Devices
Authors: DONG Li-Jia | Siying Wu | Shengbo Li | Wei Zuo-Fu | Yang Guo | Baowei Hu
Source: Journal of Inorganic Materials (article, 2019-01-01)
Field: Chemistry — Inorganic Chemistry

Sorption Behaviors and Mechanismsof Eu(III) on Rice Straw-derived Biochar Biochar, derived from agricultural residuals, is extensively applied to remove detrimental heavy metals from wastewater, which has dual significance for the environment protection. Herein, the sorption behavior and interaction mechanism of Eu(III) on rice straw-derived biochar was investigated by batch and spectroscopic technologies. The solution pH significantly affects the percentage of the sorption, but has little effect on the contact time. Biochar ; Sorption ; Materials science ; Rice straw ; Straw ; Environmental chemistry ; Chemical engineering ; Pyrolysis ; Adsorption ; Inorganic chemistry ; Physical chemistry ; Chemistry Radioactive element chemistry and processing