1,721,073 research outputs found
Effects of Self-directed Exercise Programmes on Individuals with Type 2 Diabetes Mellitus: A Systematic Review Evaluating Their Effect on HbA1cand Other Metabolic Outcomes, Physical Characteristics, Cardiorespiratory Fitness and Functional Outcomes
No full textSelf-directed exercise programmes in sedentary middle-aged individuals in good overall health; a systematic review
No full textPathways to decarbonising the transport sector: The impacts of electrifying taxi fleets
No full textThe impacts of climate change have prompted governments to pledge to introduce policies aiming to limit the increasing temperature. One of the strategies involves reducing and, eventually, eliminating internal combustion engines in favour of electric vehicles. This strategy has been implemented by many transportation services, and FREE NOW has pledged to be carbon neutral by 2030. This study analyses the FREE NOW taxi fleet composition in Dublin in 2021 and investigates the reduction in emissions from fully electrifying the fleet. The analysis uses an emissions tool to model a combination of scenarios, consisting of different vehicle powertrain and fuel type configurations. An emission factor is applied to the EVs to calculate the emissions produced by the electricity used to power the vehicles. The results show a 77% decrease in carbon dioxide emissions from fully electrifying the fleet. Multi-criteria analysis is used to assess the strengths and weaknesses of each scenario developed. The S-5 scenario, consisting of the EVs only, scored the highest for many of the criteria. S-5 was identified as the best option for the taxi fleet, followed closely by S-4 involving an upgrade to all plug-in hybrid EVs. The S-4 scenario seems to be a good alternative when an EV is too expensive or access to charging infrastructure is not provided. The infrastructure currently available in Dublin will not accommodate the all-EV taxis target by 2030
Enhanced precipitation of magnesium carbonates using carbonic anhydrase
No full textCarbonate precipitation, as part of the carbon dioxide (CO2) mineralization process, is generally regarded as a high-temperature, high-pressure, and high-purity CO2 process. Typical conditions consist of temperatures around 120 °C and a pressure of 100 bar of pure CO2, making the process costly. A major challenge facing carbonate precipitation is performing the reaction at low temperatures and low partial pressures of CO2 (pCOjavax.xml.bind.JAXBElement@43d67029) such as 25 °C and CO2 flue gas concentration. In this work, we investigated the effect of carbonic anhydrase (CA) to favor magnesium (Mg) carbonate precipitation at low temperatures and low pCOjavax.xml.bind.JAXBElement@23718aa3. CA is an enzyme that accelerates CO2 hydration promoting its conversion into HCO3− and then CO32−. This increases supersaturation with respect to Mg-carbonates. A geochemical model was implemented and used to identify supersaturated conditions with respect to Mg-carbonates. Tests were run at 25, 40, and 50 °C and at 1 bar of either pure CO2 or 10 vol% CO2 and 90 vol% N2. The concentration of 10 vol% CO2 was chosen to resemble CO2 concentration in flue gas. In selected tests, the CA enzyme was added directly as bovine CA or through microalgae (Scenedesmus obliquus). Experiments were run for 48 hours; 24 hours to reach equilibrium, then another 24 hours until the supersaturated conditions were established. After 48 hours the experiments were interrupted and the solids were characterized. Results show that the addition of CA, either directly or through Scenedesmus obliquus, enhances Mg-carbonate precipitation. Regardless of the temperature, the precipitates were made entirely of nesquehonite (MgCO3-3H2O) when pure CO2 was used. Otherwise, a solid solution containing brucite (Mg(OH)2) and MgCO3-3H2O was formed. Overall, these findings suggest that CA can promote carbonate precipitation at low temperatures, pressures, and CO2 purity. The enzyme is effective when added directly or supplied through microalgae, opening up the possibility for a CO2 mineralization process to be implemented directly at a combustion plant as a CO2 storage option without preliminary CO2 capture
mineralization and brine mining
No full textBrine mining of energy-relevant elements (EREs) requires the separation of transition metals from major cations in order to create high-purity streams. Precipitation of carbonates could be used as a separation method leaving EREs in the supernatant, therefore opening the possibility to integrate carbon dioxide (CO2) mineralization with brine mining. Major challenges are that the reaction should reach completion in few days and the inclusion of transition metals in the carbonates should be avoided. In this paper, we report an experimental and modeling work on the precipitation of calcium (Ca) carbonate in the presence of nickel (Ni), copper (Cu), and zinc (Zn). Brines of various compositions were tested to simulate brine enrichment. Atmospheric conditions were applied to study the effect of the metal concentration on the precipitation kinetics and the composition of the carbonates produced. The experiments were run in batch and monitored with inline pH and conductivity probes. Results s..
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
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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