1,720,959 research outputs found
Parametric study and simulation of Titanium Carbide (TiC) supported, Platinum doped tetrahedral Carbon (taC) electrodes for Hydrogen Evolution Reactions (HER)
No full textCompte tenu de la fiabilité de COMSOL un modèle d'étude l'expérience de Glandut et. al (2015) sur support en carbure de titane (TiC), électrode en platine dopé au carbone amorphe tétraédrique (taC:Pt) pour la réaction de dégagement d'hydrogène. Le modèle développé a été testé pour la diffusion de surface en 2D et la diffusion de surface avec effet de bord en 3D. Les résultats de la simulation montrent que la permutation des paramètres cinétiques avec la diffusivité de surface montre une certaine augmentation de la sortie de courant mais n'a pas été en mesure d'atteindre la sortie de courant obtenue à partir de l'expérience. Cependant, l'introduction d'un effet de bord du côté de taC:Pt sur le support TiC augmenterait considérablement la sortie de courant avec une grande cohérence avec le résultat expérimental. Le bord présente des propriétés cinétiques contrairement à TiC ou taC:Pt. Les paramètres cinétiques ont été déterminés à l'aide de la simulation et un ensemble de données a été trouvé pour montrer une grande cohérence avec le résultat expérimental. La diffusion de surface a été rendue inutile en raison des paramètres cinétiques extrêmement élevés sur le bord par rapport à la surface TiC et taC:Pt.Given the reliability of COMSOL a study model the experiment by Glandut et. al (2015) on Titanium carbide (TiC) support, tetrahedral amorphous carbon doped platinum (taC:Pt) electrode for hydrogen evolution reaction. The developed model was tested for surface diffusion in 2D and surface diffusion with edge effect in 3D. The simulation results show that kinetic parameters permutation with surface diffusivity shows some increased in current output but was unable to achieve the current output obtained from the experiment. However, the introduction of edge effect on the side of taC:Pt on TiC support would significantly increase the current output with great coherency to the experimental result. The edge exhibits kinetic properties unlike both TiC or taC:Pt. The kinetic parameters were determined using the simulation and a dataset was found to show great coherency with the experimental result. Surface diffusion was rendered useless because negligible compared to the extremely high kinetic parameters on the edge in comparison to the TiC and taC:Pt surface
Étude paramétrique et simulation d'électrodes en carbone tétraédrique (taC) supportées par du carbure de titane (TiC) pour les réactions d'évolution de l'hydrogène (HER)
No full textGiven the reliability of COMSOL a study model the experiment by Glandut et. al (2015) on Titanium carbide (TiC) support, tetrahedral amorphous carbon doped platinum (taC:Pt) electrode for hydrogen evolution reaction. The developed model was tested for surface diffusion in 2D and surface diffusion with edge effect in 3D. The simulation results show that kinetic parameters permutation with surface diffusivity shows some increased in current output but was unable to achieve the current output obtained from the experiment. However, the introduction of edge effect on the side of taC:Pt on TiC support would significantly increase the current output with great coherency to the experimental result. The edge exhibits kinetic properties unlike both TiC or taC:Pt. The kinetic parameters were determined using the simulation and a dataset was found to show great coherency with the experimental result. Surface diffusion was rendered useless because negligible compared to the extremely high kinetic parameters on the edge in comparison to the TiC and taC:Pt surface.Compte tenu de la fiabilité de COMSOL un modèle d'étude l'expérience de Glandut et. al (2015) sur support en carbure de titane (TiC), électrode en platine dopé au carbone amorphe tétraédrique (taC:Pt) pour la réaction de dégagement d'hydrogène. Le modèle développé a été testé pour la diffusion de surface en 2D et la diffusion de surface avec effet de bord en 3D. Les résultats de la simulation montrent que la permutation des paramètres cinétiques avec la diffusivité de surface montre une certaine augmentation de la sortie de courant mais n'a pas été en mesure d'atteindre la sortie de courant obtenue à partir de l'expérience. Cependant, l'introduction d'un effet de bord du côté de taC:Pt sur le support TiC augmenterait considérablement la sortie de courant avec une grande cohérence avec le résultat expérimental. Le bord présente des propriétés cinétiques contrairement à TiC ou taC:Pt. Les paramètres cinétiques ont été déterminés à l'aide de la simulation et un ensemble de données a été trouvé pour montrer une grande cohérence avec le résultat expérimental. La diffusion de surface a été rendue inutile en raison des paramètres cinétiques extrêmement élevés sur le bord par rapport à la surface TiC et taC:Pt
Étude paramétrique et simulation d'électrodes en carbone tétraédrique (taC) supportées par du carbure de titane (TiC) pour les réactions d'évolution de l'hydrogène (HER)
No full textGiven the reliability of COMSOL a study model the experiment by Glandut et. al (2015) on Titanium carbide (TiC) support, tetrahedral amorphous carbon doped platinum (taC:Pt) electrode for hydrogen evolution reaction. The developed model was tested for surface diffusion in 2D and surface diffusion with edge effect in 3D. The simulation results show that kinetic parameters permutation with surface diffusivity shows some increased in current output but was unable to achieve the current output obtained from the experiment. However, the introduction of edge effect on the side of taC:Pt on TiC support would significantly increase the current output with great coherency to the experimental result. The edge exhibits kinetic properties unlike both TiC or taC:Pt. The kinetic parameters were determined using the simulation and a dataset was found to show great coherency with the experimental result. Surface diffusion was rendered useless because negligible compared to the extremely high kinetic parameters on the edge in comparison to the TiC and taC:Pt surface.Compte tenu de la fiabilité de COMSOL un modèle d'étude l'expérience de Glandut et. al (2015) sur support en carbure de titane (TiC), électrode en platine dopé au carbone amorphe tétraédrique (taC:Pt) pour la réaction de dégagement d'hydrogène. Le modèle développé a été testé pour la diffusion de surface en 2D et la diffusion de surface avec effet de bord en 3D. Les résultats de la simulation montrent que la permutation des paramètres cinétiques avec la diffusivité de surface montre une certaine augmentation de la sortie de courant mais n'a pas été en mesure d'atteindre la sortie de courant obtenue à partir de l'expérience. Cependant, l'introduction d'un effet de bord du côté de taC:Pt sur le support TiC augmenterait considérablement la sortie de courant avec une grande cohérence avec le résultat expérimental. Le bord présente des propriétés cinétiques contrairement à TiC ou taC:Pt. Les paramètres cinétiques ont été déterminés à l'aide de la simulation et un ensemble de données a été trouvé pour montrer une grande cohérence avec le résultat expérimental. La diffusion de surface a été rendue inutile en raison des paramètres cinétiques extrêmement élevés sur le bord par rapport à la surface TiC et taC:Pt
Parametric study and simulation of a heat-driven adsorber for air conditioning system employing activated carbon–methanol working pair
No full textAbstractObjectivesThis paper aims to present a parametric study to compare with the experimental results obtained previously for a typical activated carbon–methanol, adsorption air-conditioning system powered by exhaust heat. The main objective is to study the effect of wall thickness on the desorption temperature and the cooling performance.MethodsThe current study is a simulation/parametric investigation employing computational fluid dynamics (CFD) simulation technique.ResultsIt is found that the CFD result is close to the experimental works. In this CFD investigation, an input exhaust gas of 200°C would have bed temperature around 120°C while employing 20mm thick of wall made by stainless steel. The adsorber took around 10min to heat up and decrease to room temperature around the same period. This set of data produce a cooling power of 0.65kW and COP around 0.25 with cycle time of 1200s.ConclusionIt is concluded that higher input temperature would have relatively longer cycle time but it is able to produce higher cooling power in return. While in design, it proves that an optimal wall thickness should be 15–20mm of stainless steel that offer lower heat transfer rate to maintain the system under functional Tdes at all time.Practice implicationsThis paper proves that adsorption air-conditioning system is technically applicable; however wall thickness of the adsorber should be considered seriously as one of the important parameters for suitable heat transfer and improved adsorption–desorption rate of the system
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The sorption studies of waste cooking oil using raw and treated pineapple crown leaf / Rabuyah Ni ... [et al.]
Get PDFThe unregulated discharge of pollutants into water bodies has become an issue that led to pollution. Fiber derived from various forms of agricultural wastes as the sorbent is widely used as it has a high sorption capacity and efficiency. It is environmentally friendly and could be cost-effective as it only utilizes the unwanted parts of plants, which usually would otherwise be discarded. The pineapple crown leaf (PCL) and other plants with high cellulose content have the potential for environmental applications. Oil pollutants, particularly waste cooking oil (WCO) from the food and beverage industry, often contaminate water bodies due to poor waste management. Using cellulose-rich plants like PCL could offer an effective solution for absorbing these pollutants. This study examines the characteristics and sorption capacities of raw, NaOH-treatment PCL, and carbonized PCL to develop an effective, eco-friendly method for oil spill remediation. The methodology involves washing, drying, grinding, and sieving PCL to obtain a powdered PCL. Then, raw PCL (RPCL) undergoes chemical treatment with 10% sodium hydroxide, NaOH and thermal treatment at 300 °C. The raw and treated PCL were characterized using Fourier Transform Infrared Spectroscopy (FTIR). The elimination of some non-cellulosic components in NaOH-treatment PCL (CPCL) and carbonized PCL (TPCL) observed in the FTIR spectrum would contribute to higher sorption efficiency and capacity of WCO. In agreement with the results from FTIR analysis, the highest sorption efficiency in pure oil was shown by TPCL at 33% and CPCL in slick oil at 16.33%. The highest value for pure and slick oil recorded for sorption capacity was 9.23 g g−1 from TPCL samples and 4.3 g g−1 from CPCL samples. This study supports sustainable waste management and green technology for environmental remediation, highlighting PCL's potential in mitigating oil pollution and the value of agricultural waste in creating eco-friendly solutions for oil disposal challenges
Kinetic study and simulation of molybdenum borides for hydrogen evolution reaction
Get PDFThis paper presented the kinetic study of molybdenum borides via the Volmer-Heyrovsky-Tafel (V-H-T) mechanistic steps for hydrogen evolution reaction (HER). A theoretical approach was carried out to investigate the kinetic properties of several molybdenum boride materials for HER in 0.5 M H2SO4. Our findings offer definitive proof that the simulated results show that B, Mo, Mo2B, and α-MoB, proceed through V-H mechanistic steps (slower kinetics) while β-MoB and MoB2 exhibit V-H-T mechanistic steps with higher kinetics. The kinetic parameters were determined in terms of the standard rate constant parameters for the Volmer step (kV, k-V), Heyrovsky step (kH, k-H), and rate constant for the Tafel step (kT, k-T). The simulation was able to predict the overpotential at 10 mA/cm2, η10 recorded at approximately 780, 585, 480, 350, 310, and 300 mV for B, Mo, Mo2B, α-MoB, β-MoB, and MoB2 respectively. Based on these findings, the adopted mathematical model shows good coherency to the experimental findings. The simulation work provides a good numerical estimation of the characteristics of the electrocatalyst for HER. This paper successfully elucidated the reaction mechanisms (V-H-T steps) and understood the rate-limiting steps involved in the HER process on Mo-B materials
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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