1,720,998 research outputs found
Modelling the Italian household sector at the municipal scale: Micro-CHP, renewables and energy efficiency
Full text linkThis study investigates the potential of energy efficiency, renewables, and micro-cogeneration to reduce household consumption in a medium Italian town and analyses the scope for municipal local policies. The study also investigates the effects of tourist flows on town's energy consumption by modelling energy scenarios for permanent and summer homes. Two long-term energy scenarios (to 2030) were modelled using the MarkAL-TIMES generator model: BAU (business as usual), which is the reference scenario, and EHS (exemplary household sector), which involves targets of penetration for renewables and micro-cogeneration. The analysis demonstrated the critical role of end-use energy efficiency in curbing residential consumption. Cogeneration and renewables (PV (photovoltaic) and solar thermal panels) were proven to be valuable solutions to reduce the energetic and environmental burden of the household sector (−20% in 2030). Because most of household energy demand is ascribable to space-heating or hot water production, this study finds that micro-CHP technologies with lower power-to-heat ratios (mainly, Stirling engines and microturbines) show a higher diffusion, as do solar thermal devices. The spread of micro-cogeneration implies a global reduction of primary energy but involves the internalisation of the primary energy, and consequently CO2 emissions, previously consumed in a centralised power plant within the municipality boundaries
Distributed Stirling Engines for Pipeline Corrosion Protection
No full textOil or gas transportation requires the use of very long pipelines from the source of extraction to the main distribution grids. However, due to the properties of the inner fluids and to the differing environmental conditions, these pipelines are particularly prone to corrosion. To guarantee the longevity of pipelines, protective coatings and/or anodic or cathodic protection are commonly used. In conjunction with protective coatings, cathodic protection is often considered the wisest solution and is therefore widely adopted. In remote areas, where power supply is not easily available from the grid, power units are distributed along the course of the pipeline to overcome this shortage. Thanks to their impressive operating longevity without maintenance, off-grid Stirling engines are well-suited to this purpose as they can be used as power generators in remote areas where operat/are occasional.
A 1kWe Stirling engine has been designed to ensure the protection of over 5 kilometers of pipeline length, conditioning the corrosion protection control units and powering the SCADA systems.
Market analysis has shown very good opportunities for off grid configuration Stirling engines in the oil and gas sector, thus extending their current application in the household sector as micro combined heat and power systems.
According to a low profile estimate, protection of 2000 km of pipeline length can be ensured through the use of Stirling engines, /promising an important economic profit
Onboard Hybrid Propulsion and Sewage Treatment System Powered by a Stirling Engine Unit
No full textAt present, boats have to comply with very strict environmental regulations on emission production and sewage disposal. In the near future, new environmental policies on reduction of water pollution will also affect sailing boats. To reach environmental targets, a few models of new boats on the market are equipped with hybrid propulsion systems in which an electric generator is combined with a diesel engine. The electric generator, driven by the diesel engine, charges a bank of batteries which in turn powers an electric motor. The electric motor can operate in parallel with the main propulsion engine to provide more power output or on its own, when a quieter and more fuel-efficient operating performance is required during idling or docking.
In this paper a Stirling engine is considered for the onboard application. The main advantage is that a Stirling engine can run continuously to charge the bank of batteries in the hybrid propulsion system or to supply power on request for onboard appliances, all whilst producing a very little noise. In addition, the heat discharged by the cooling system of the engine can be utilized for onboard sewage treatment. New environmental regulations limit the sewage disposal at ports thus making it necessary to store and treat sewage during navigation. In order to reduce sewage disposal, the engine’s thermal output is used to aid evaporation thereby reducing the quantity of waste disposed.
In this work, the authors have studied the integration of hybrid propulsion and sewage treatment systems powered by a Stirling engine in order to meet these new environmental regulations and provide comfort during the navigation of sailing boats. It is anticipated that experimental tests will be carried out after once the design stage of the system has been completed
Local authorities in the context of energy and climate policy
No full textSeveral measures to boost the energy system towards a low-carbon future can be planned and implemented by local authorities, such as energy-saving initiatives in public buildings and lighting, information campaigns, and renewable energy pilot projects. This work analyzes the public administration's role in energy and climate policies by assessing carbon-lowering measures for properties and services managed directly by local governments in central Italy.
Both short- and long-term schemes were considered in the analysis of local authority energy strategies. The MARKAL-TIMES energy model was applied to long-term energy planning to assess the effect of low-carbon initiatives on public-sector energy consumption up to 2030. Two energy scenarios were built, i.e. a Business As Usual (BAU) scenario based on current or soon-to-be-adopted national policies, and an Exemplary Public Scenario (EPS) including some further virtuous local policies suggested by local authorities.
Our results show that a 20% primary energy reduction can be achieved with respect to the baseline year by means of short-term energy policies (5-year time span), while a primary energy saving of about 30% can be reached with longer-term energy policies (25-year time span), even after taking the increase in energy demand into account.
This work goes to show the part that local governments can play in energy policy and their contribution to the achievement of climate goals
Analysis of a micro-CHP system consisting of steam injected gas turbine fed by syngas and integrated with bottoming Organic Rankine Cycle
No full textIntegration of energy systems is an effective strategy to achieve higher efficiency and to reduce the emissions in power systems, which has been studied by many researchers for different applications and system configurations. Steam Injected micro Gas Turbine (SImGT) coupled to bottoming Organic Rankine Cycle (ORC) can be a way to achieve higher efficiency and to reduce the emissions in small-scale biomass power plants. In this study, a 1-dimensional model of a steam fluidized-bed gasifier has been coupled with a dynamic model of a SImGT and a zero-dimensional model of a bottoming ORC in order to investigate the performance of such system. A Heat Recovery Steam Generating (HRSG) is adopted in the design of the integrated system to produce steam for both the gasification process and the SImGT. Results of the simulation under steady-state condition show that the designed system can produce 114.6 kWel and 81.3 kWth with 33.6 % electric efficiency using 25 g/s steam injected to the combustion chamber
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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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