1,720,961 research outputs found
Assessment and Public Reporting of Geothermal Resources in Germany: Review and Outlook
Get PDFAny geothermal resource assessment requires consistent and widely accepted terminology, methods, and reporting schemes that facilitate the comparison of geothermal resource estimates. This paper reviews common resource assessment methods, as well as reporting codes and terminology. Based on a rigorous analysis of the portrayed concepts and methods, it discusses the appropriateness of the existing reporting codes for sustainable utilization of geothermal resources in Germany. Since the last quantitative geothermal resource assessment in Germany was done 15 years ago, a revised report is overdue. Unlike fossil energy commodities, geothermal energy replenishes naturally and heat recuperation increases in created heat sinks. This replenishment process offers the opportunity for sustainable reservoir management in the case of moderate production rates or cyclic operation. Existing reporting codes, however, regard geothermal resources in a similar way to fossil resources or focus too much on field development rather than on the whole assessment process. In order to emphasize the renewability of geothermal energy, we propose the reporting of geothermal capacities (per doublet or per km2) instead of recoverable heat energy which depends very much on project lifetime and other factors. As a first step, a new classification scheme for geothermal resources and reserves is outlined
Temporal Variations of delta 2 H, delta 18 O and Deuterium Excess in Atmospheric Moisture and Improvements in the CO 2 -H 2 O Equilibration Technique for 18 O/ 16 O Isotope Ratio Analysis
No full textA continuous 18-year record (1981-2000) of the stable isotope ratios D/H and 18O/16O in atmospheric water vapour collected at the Central European site Heidelberg (49° 25’ N and 8° 41’ E) is analysed. Its basic features, such as seasonal variations of D/H and 18O/16O, are discussed and compared with the isotope composition of precipitation. The correlation between local air temperature and isotopic composition of water vapour and precipitation is nearly identical for annual, but not for monthly means. This study focuses on the deuterium excess in water vapour, d(vap), such as its difference to the mostly analysed deuterium excess in precipitation, d(prec). Both d’s are assumed to be controlled primarily by the moisture deficit above the ocean, the major source of atmospheric moisture. In order to understand the seasonal and short-term variations of d(vap), the isotopic evolution of the moisture along 5-day backward trajectories is analysed. Although the subtropical Atlantic is an important moisture source for Europe, variations of deuterium excess are shown to be controlled by regional evaporation. This study also presents details of an optimized CO2-H2O equilibration device for 18O/16O measurements in water. A system designed for high throughput has been modified to yield results of excellent precision while keeping the operator time at a minimum. Results of an 18-months study of three laboratory standard waters and an international interlaboratory comparison organized by the IAEA shows the high analytical precision of 18O/16O determinations in natural waters now available
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
The ArtemIS project: Assessment for medium-depth geothermal energy utilization in Germany
No full textTo date, most geothermal projects in Germany have focused on deep geothermal systems, while resources at intermediate depths have only been explored to a small extend. However, medium-depth geothermal systems have a high potential for heat generation, even in areas previously considered less favorable for deep geothermal energy, and could make a significant contribution to Germany's heat supply. To accelerate the heat transition and to become independent of fossil fuels, the ArtemIS project aims to assess the medium-depth geothermal systems in Germany, covering all types of geological plays and providing regional information for different geothermal applications. Interactive heat transition profiles are being developed containing all relevant subsurface information required for preliminary geothermal assessment, such as geological descriptions of potential geothermal reservoirs, reservoir thickness, hydraulic and thermal rock properties, and fluid chemistry. In addition, static 3D geological models are being created as the basis for 3D numerical reservoir models using COMSOL Multiphysics to simulate the regional heat potential and different geothermal scenarios, including the performance of hydrothermal doublets. The investigation of well logs and core sample data of the Upper Maastrichtian Calcarenites in the North German Basin indicates a good geothermal potential, but notable lateral and vertical heterogeneities regarding reservoir thickness, grain size or glauconite content throughout the study area need to be considered during exploration. The first COMSOL simulation results highlight the impact of inter-well distance and reservoir thickness on operational parameters such as the occurrence time of thermal breakthrough and cooling rate in a multi-well array. Likewise, a 3D structural model of the Upper Rhine Graben was created and used to assess the regional heat supply, indicating a high potential for heat production in the sedimentary units at intermediate depths. The results of the ArtemIS project will be integrated into the publicly available web platform "Geothermal Information System – GeotIS", which will provide general information, data, and modelling results in a user-friendly way for non-professionals such as local communities and municipal energy suppliers
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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