1,720,985 research outputs found
Evaluating outlet working fluid’s temperature by implementing closed-loop geothermal systems in decommissioned hydrocarbon wells: the case studies of San Benigno and Cinzano wells
Full text linkAbandoned hydrocarbon wells offer significant potential for extracting geothermal energy from the subsurface if effectively repurposed. Among the discussed geothermal systems, closed-loop wellbore heat exchangers (WBHEs) represent one of the most promising technologies. Simplified methods to assess the exploitable temperature potential of decommissioned wells, using coaxial and U-tube WBHEs and integrating geological and technical considerations, have been developed and are available in the literature. Such solutions are useful tools for evaluating the suitability of a selected well for geothermal repurposing during the preliminary analysis phase. This study focuses on the application of simplified approaches for the preliminary assessment of the extracted temperature following the implementation of coaxial and U-tube WBHEs in the San Benigno and Cinzano wells, leveraging on-site temperature data. These assessments allowed the identification of these wells as economically unsuitable for repurposing, unlike others studied and located within the Italian territory
A Preliminary Analysis for Understanding Variations in Mountain Springs’ Water Availability under Climate Change in Aosta Valley
Full text linkThe availability of freshwater resources in alpine mountain areas has been affected by the impacts of climate change on groundwater storage mechanisms. A web of complex interactions characterizes climate systems, and several potential effects of climate change in such areas remain largely unknown. Therefore, examining how groundwater storage mechanisms are changing in response to climate-driven agents is becoming increasingly crucial.
To comprehend the existing relationship between changes in weather conditions and water availability in the Aosta Valley region (Northwestern Italy) and how their trends have changed over the last decade, a 7-year discharge series of different Aosta Valley springs (Promise, Alpe Perrot, Promiod, Cheserod) and precipitation data of the related meteorological stations (Aymaville-Viayes, La Thuile-Villaret, Champdepraz, Sant Vincent) were analyzed. The extent of the correlations between springs discharge measurements and hydrometeorological data was investigated. Besides, precipitation and flow rate trend analyses using the Mann–Kendall and Sen’s slope trend detection tests were performed. The Aymaville-Viayes, La Thuile-Villaret, Champdepraz, and Sant Vincent meteorological stations revealed an overall decreasing trend in annual rainfall (mm), with a slight increase in intensity (mm/day) as a result of the reduction in rainfall events (number of rainy days). Nonetheless, based on the analysis of flow rate data relating to the associated springs, Alpe Perrot, Cheserod, and Promise show an overall increasing trend of discharge over time. Although the Cheserod and Promise springs were not found to be highly correlated with rainfall, their aquifers appear to positively respond to the modified climate conditions, increasing the amount of groundwater stored. The moderate correlation values of these two springs can be a consequence of several factors such as aquifer features, distance from the weather station, and solid precipitation amounts that supply water in the following hydrogeological year.
Being able to continuously monitor the effects induced by changed climatic conditions on water reserves through simplified analysis approaches such as those presented in this paper is increasingly necessary. Moreover, implementing future studies through in-depth analyses of soil infiltration, groundwater recharge and storage mechanisms are required to predict the mountain aquifers’ behavior in changing climatic conditions
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
COMPREHENDING MOUNTAIN SPRINGS’ HYDROGEOLOGICAL PERSPECTIVES UNDER CLIMATE CHANGE IN AOSTA VALLEY (NORTHWESTERN ITALY): NEW AUTOMATED TOOLS AND SIMPLIFIED APPROACHES
Full text linkMountain springs' recharging mechanisms have undergone significant changes due to climate change, as well as altered water consumption patterns and policies. Specifically, climate change has influenced the characteristics of spring discharges, evapotranspiration, snow-rainfall ratios, and snow seasonality, bringing new rainfall patterns associated with increased average air temperatures. Consequently, examining how groundwater storage mechanisms are changing in response to climate-driven has become crucial for understanding the future scenarios associated with water availability in such areas. Therefore, increasingly automated tools and simplified approaches need to be applied to continuously monitor hydrogeological variables affecting the spring recharge system. SOURCE (a semi-automatic tool for Spring mOnitoring data analysis and aqUifeR CharactErization) is an advanced semi-automatic Python tool that automates the hydrogeological characterization of the springs' aquifers. Its functionalities were tested through the analysis of the Promise and Alpe Perrot mountain springs and the related meteorological stations (La Thuile-Villaret and Champdepraz-Chevrere) located in the Aosta Valley region (NW Italy). Input data (flow rate, temperature, electrical conductivity, and rainfall) can be rapidly processed, providing graphical outputs, as well as values for the main hydrodynamic parameters (e.g. auto and cross-correlation coefficients) for an aquifer. Besides, to comprehend the relationship between changes in weather conditions and water availability in the Aosta Valley Region (Northwestern Italy), 7-year precipitation and discharge trends were considered. Despite the increasing trends in flow rate, considering the limited vulnerability values obtained for Alpe Perrot, it is possible to hypothesize a delayed impact of climatic changes on the spring system. The impact of climatic changes on Promise spring is supposed to be faster. However, the nature and dimensions of the aquifer are such as to be resilience to increasing water temperature. Being able to continuously monitor and define the effects induced on water reserves through simplified analysis approaches, such as those presented in this paper, is increasingly necessary, especially for local authorities. A single software package such as SOURCE that contains all the main methods of water spring analysis has the potential to significantly reduce any analysis times
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
Groundwater heat pump systems diffusion and groundwater resources protection
Full text linkGeothermal Energy, being a clean and sustainable source of energy, is gaining importance worldwide due to various reasons. Geothermal power can be generated throughout the year on twenty four hour basis as it's not much dependent on ambient temperature and weather conditions. Recently there is an increased interest in exploitation of low enthalpy geothermal resources for other applications such as geothermal space heating and cooling for domestic, industrial and commercial applications.GroundWater Heat Pump systems (GWHPs) extract water from one or more wells, pass it through a heat exchanger or a heat pump, which either extracts heat from, or rejects heat, and discharge water back into the aquifer or nearby surface water.This reinjection disturbs the natural aquifer temperature, producing a local temperature anomalies (cold or heat plume) known as the thermal affected zone (TAZ).Moreover, it is important to know if the TAZ can interfere with downgradient pre-existing plants or subsurface infrastructure or with the plant itself (thermal feedback). It is then important to know, even before constructing a GWHP system, the future TAZ extent around the planned injection point.Due to these risks, the increasing number of GWHP systems enforces the need for new criteria to develop subsurface energy policies that allow planning their spatial distribution. To obtain these sustainability criteria, the results of different dedicated studies are here proposed, in order to optimize the design and operation of GWHP systems
Reliability of spring recession curve analysis as a function of the temporal resolution of the monitoring dataset
Full text linkMountain springs represent one of the largest and most precious sources of potable water in Italy, necessary to meet the water needs of the population. Optimizing the present and future management strategies of mountain groundwater resources has become increasingly necessary. The accuracy and frequency of the flow rate (Q) measurements determine and restrict the processes that can be studied using spring hydrograph and recession curve analysis. Therefore, to properly define mountain aquifers’ hydrogeological properties, it turns out important to highlight the variation of the error in the estimation of the hydrogeological parameters as the time interval of sampling varies. In this paper, recession curve analysis was performed on two different mountain springs (Spring 1 and Spring 2) of north-western Italy, firstly considering available 4-h resolution measuring data and subsequently by resampling data to simulate longer sampling intervals of 1, 3, 7, 15, and 30 days. The resulting distribution of errors introduced by longer acquisition intervals underlined how the percentage error increases with increasing acquisition interval. For obtaining an adequate estimation of mountain aquifer hydrodynamic parameters, in place of continuous hourly data, 1-day and 3-day sampling intervals with associated errors respectively lower than 5% and 10% were found to be valid
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