1,721,005 research outputs found
Optimizing anaerobic digestion of organic fraction of municipal solid waste (OFMSW) by using biomass ashes as additives
No full textThe purpose of this study is to test alternative additives for trace element (TE) supplementation and process stabilization during anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) and sewage sludge. Process instabilities due to acidification are a typical problem in waste fermentation. Provision with minerals and TE is crucial for microorganisms in AD to work effectively, allowing higher organic loading rates within the digester without risking acid accumulation. In batch-fermentation tests, different mixture configurations of OFMSW, digested sewage sludge and biomass ashes were evaluated. Based on an extensive characterization of the TE contained in wood ashes, suitable combinations of digested sewage sludge and OFMSW as a baseline substrate together with ash additives were derived. While high dosages of ash reduced biogas production, 1:1 mix of ash and OFMSW facilitated higher CH4 yields (6%). The supplementation of ashes increased the pH-value within AD and CO2 precipitation through metal oxides in situ elevated the CH4 concentration in biogas up to 98%. Therefore, ashes may increase the efficiency of AD and serve as a basis for a new gas purification method, minimizing technical effort. Additional investigations are needed to examine long-term effects as well as financial and legal aspects such as possible ways of digestate usage. As a further area of research, the transferability of batch-test results into practical applications is identified
Dataset for a full-year time series characterization of separately collected organic fraction of municipal solid waste from rural and urban regions in Germany
No full textIn the municipal context and depending on the collection scheme, different waste streams are of relevance. This article contains year-round data on the chemical composition of organic fractions of municipal solid waste (OFMSW) of rural and urban origins. All samples were collected in the municipality of Tübingen, which is located in southern Germany. The sampling procedure was executed in accordance with standard procedures mentioned in the German Biowaste Ordinance. The data presented in this article include (1) sampling area and process specifications (2) organoleptic examinations (3) dry matter and organic dry matter contents (4) impurity concentrations and (5) elemental compositions (major, minor and trace elements). All datasets are presented as a time series for the year 2018. Thus, this article especially presents the influence of season and settlement structure on the physico-chemical characteristics of OFMSW. Researchers, waste management companies and municipalities can compare and expand their own OFMSW data with those presented in this article. The dataset can also be used to calculate energy yields of OFMSW when utilized in anaerobic digestion. Based on the data, it is also possible to discuss and to evaluate the material utilization of OFMSW-based digestates and compost products, especially with regard to concentrations of major, minor and trace elements. For further discussion, please refer to the original scientific article Sailer et al. (2021)
Characterization of the separately collected organic fraction of municipal solid waste (OFMSW) from rural and urban districts for a one-year period in Germany
No full textDatasets on chemical composition and anaerobic digestion of organic fraction of municipal solid waste (OFMSW), digested sewage sludge (inoculum) and ashes from incineration or gasification
No full textThis article contains data on the chemical composition and anaerobic digestion of different residue streams including OFMSW, digested sewage sludge, low-carbon (LC) ashes from incineration subdivided into LC coarse and LC fly ash as well as high-carbon (HC) ashes from gasification subdivided into HC reactor and HC fly ash. All materials were collected in accordance to standard procedures in southern Germany. The data presented in this article include (1) dry matter (2) organic dry matter (3) elemental analysis (4) trace elements and (5) cumulative biogas and CH4 yields. Researchers and waste management companies on lab-/pilot-/industrial-scale can rely on the presented data for classification and comparison of biogenic waste streams. For further discussion, please refer to the scientific article entitled "Optimizing anaerobic digestion of organic fraction of municipal solid waste (OFMSW) by using biomass ashes as additives" [ 1 ]
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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