1,354,060 research outputs found
Addressing Safety and Risk Mitigation in Academic Laboratories: a Case Study
No full textThis study addresses the critical need for effective risk assessment and mitigation strategies in academic research environments. As research laboratories engage in increasingly complex projects, ensuring the safety of personnel, equipment, and the surrounding environment becomes paramount. These settings are prone to various vulnerabilities, including manual operations, transient states, and diverse training backgrounds. This work presents a case study focusing on the potential hazards and risks associated with Fischer-Tropsch synthesis. The analysis examines critical factors such as catalyst use, high-temperature reactions, potential byproducts, and the influence of human error during manual operations. Utilizing a systematic approach that incorporates interaction matrices and HAZOP analysis, the study identifies potential undesired scenarios, ranging from minor incidents to severe consequences, and evaluates their likelihood and impact. In response to the identified risks, the paper proposes targeted mitigation measures specifically designed for the Fischer-Tropsch experimental setting, structured as layers of protection. The findings of this research offer valuable insights into laboratory safety in academic settings, providing a risk assessment and mitigation model adaptable to various experimental setups. By integrating theoretical frameworks with practical applications, this study aims to enhance safety standards in academic laboratories conducting Fischer-Tropsch synthesis and establish a foundation for continuous improvement in laboratory practices
Predicting FTS products through artificial neural network modelling
No full textFischer-Tropsch synthesis is essential for converting CO2 into hydrocarbons, creating sustainable fuels and olefins. However, challenges in production yield and reaction kinetics remain. This study introduces an artificial neural network (ANN) to predict FT synthesis products from specific inputs, including temperature, pressure, GHSV, H2/CO2 ratio, and catalyst composition (Fe weight and K as a promoter). The ANN's ability to predict outputs like CH4, C2-4, C5+, CO2 conversion, and CO selectivity, without detailed reaction mechanisms, is a key innovation. This approach circumvents complex kinetic models. The network architecture is optimized for minimal error, and results are validated against a comprehensive database
Magnetic Adsorbents/Photocatalysts for Water Purification: Progress and Challenges
No full textPhotocatalysis requires the activation of photocatalytic materials by light to produce a redox system able to oxidize/reduce (in)organic pollutants. Photocatalysts in suspension form provide excellent oxidation of pollutants in water due to excellent mass transfer. However, the recovery of photocatalyst particles is challenging and costly at large scale. To solve this, numerous studies on the immobilization of photocatalysts on substrates have been reported, to avoid treatment steps or/and for better recovery of particles. This approach suffers from slow kinetics due to less mass transfer, and is not competitive with existing technologies. Magnetically recoverable photocatalysts for water treatment are innovative materials that can be used for high efficiency and ease of handling: they can be used as suspensions, ensuring maximum mass transfer, and recovered by external magnetic force. This chapter aims to discuss recent progress in the design and application of magnetic-based materials for water treatment. Their synthesis and performance in water treatment are clarified. Their catalytic role to catalyse Fenton agents and NaBH4 for organic pollutant oxidation is addressed. In addition, their photocatalytic mechanistic pathways and (photo)catalytic role are discussed. Since magnetic materials exhibit low stability and high charge, recombination as magnetic nanoparticles that can play the roles of recombination center and insulator are discussed, emphasizing the mechanisms and synthesis conditions
Iron Based Nano-hydrotalcites Promoted with Cu as Catalysts for Fischer-tropsch Synthesis in Biomass to Liquid Process
No full textTwo different groups of MgCuFe catalysts derived from hydrotalcite-like precursors were prepared through ultrasound-assisted (US) co-precipitation and solvent-free ball milling methods (BM). The catalysts were activated at 623°K, 1.5 MPa for 4 h in syngas, and their performances in the production of fuels through Fischer–Tropsch (FT) synthesis were evaluated in a fixed bed reactor at temperatures ranging from 473° to 573°K and 2 MPa and H2/CO molar ratio of 2. The physicochemical properties of the fresh and spent catalysts were investigated and characterized using different methods, including XRPD, ICP-OES, SEM, and TEM. Catalysts displayed similar catalytic activity for both BM and US with minor differences when operating at temperatures from 473° to 523°K. The results hint at the possibility of using synthetic hydrotalcites as Fe-based catalysts for the Fischer–Tropsch synthesi
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Variations on the Author
No full text“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
Determination of vapour pressures of FAME industrial mixtures by ebullioscopic and thermogravimetric experimental methods
No full textVapour pressure (VP) is a parameter that characterizes, by principle, only pure compounds. Nevertheless, it can refer also to mixtures in order to characterize their volatility or to be inserted in technical documents. The measurement of VP for mixtures is strongly dependent on the possible variation of the composition, during experiments, due to the different volatility of the constituent compounds. It is possible to calculate the VP of the mixture starting from its composition, but different thermodynamic scenarios must be considered. Moreover, for industrial samples, possible effects due to the presence of impurities must be considered. In this work, two different experimental methods have been employed to determine VP of some acetates esters and two industrial mixtures of fatty acid methyl esters (FAME). The first method is a direct ebullioscopic method, while the second is an indirect thermogravimetric analysis (TGA). An error function was calculated to compare the experimental results of VPs obtained with the two methodologies with the theoretical ones. Ebullioscopic measures resulted suitable only for acetates esters, as FAME mixtures are characterized by VPs too low to be quantified with this technique. On the contrary, TGA methodology is more accurate for FAME than acetates. It allows the collection of a great number of VP values with a very fast analysis. This method is less accurate than others, but it can be useful for a fast screening of the FAME mixtures, also contaminated with light impurities
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Simulated-Experimental Cross Validation of Multistage Batch Distillation for Water/Propylene Glycol Separation as Educational Exercise
No full textThis study describes an educational exercise concerning the multistage batch distillation of the mixture water-propylen glycol (PG). The research study consisted of three primary components: practical experimentation using a batch distillation setup, computer simulations, utilizing the AVEVA PRO/IITM software, and the development and operation of a multistage system. The initial experiment was centred around the process of distillation involving mixtures of n-heptane/toluene and water/PG. This phase aimed to establish a fundamental understanding that would be crucial for conducting further simulations using the AVEVA PRO/IITM platform. The utilisation of these simulations is the basic background in customizing the design and optimizing the performance parameters of the multistage distillation plant, hence guaranteeing the highest possible level of separation efficiency
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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