1,721,022 research outputs found
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
BioENergy SImulation Model
No full text<p>Model for simulating least-cost biofuel deployment in scenarios for greenhouse gas abatement in the German transport sector, as described in <strong>Millinger, M.</strong>, Meisel, K., Budzinski, M., Thrän, D., (2018): Relative greenhouse gas abatement cost competitiveness of biofuels in Germany, <em>Energies</em> <strong>11</strong> (3), 615: <a href="https://doi.org/10.3390/en11030615">https://doi.org/10.3390/en11030615</a></p>
BioENergyOPTimisation model
No full text<p>Model for greenhouse gas optimal allocation of biomass across transport sectors in Germany, as described in <strong>Millinger, M.</strong>, Meisel, K., Thrän, D., (2019): Greenhouse gas abatement optimal deployment of biofuels from crops in Germany. <em>Transport. Res. Part D-Transport. Environ.</em> <strong>69</strong> , 265 - 275: <a href="https://doi.org/10.1016/j.trd.2019.02.005">https://doi.org/10.1016/j.trd.2019.02.005</a></p>
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
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
Systems assessment of biofuels: Modelling of future cost and greenhouse gas abatement competitiveness between biofuels for transport on the case of Germany
Full text linkBiofuels are a renewable alternative for reducing the climate impact of transport.
Due to the versatility of biomass and complexity of economics and impacts, biofuels are part of a complex system, which is here analysed from a systems perspective. Several models are developed in order to assess the competitiveness of various crop based biofuel options as part of a system, using different economic and environmental functional units. The scope is set to Germany until 2050.
The capital and feedstock costs were revised to higher levels compared to common assumptions. The different functional units result in different merit orders for the biofuel options. Currently used biofuels, rape seed based biodiesel and starch crop based bioethanol, were found not to be competitive when considering differentiated and increasing feedstock costs. Advanced liquid fuels were only competitive at extreme assumptions, contrary to common expectations. Instead, sugar beet based ethanol dominated for most of the time span when comparing energetic cost, whereas Synthetic Natural Gas (SNG) was competitive on a greenhouse gas abatement (GHG) cost basis, especially at a rapid decarbonisation of the power mix. With a land use GHG abatement functional unit, silage maize based biomethane was the best, with SNG converging only at very high renewables shares of the background systems.
Switching from current practise to higher yielding biofuel options can treble the abatement per land area for the present day, and potentially increase it by a factor five in the future. A focus on GHG abatement per area of arable land results in the land passenger transport sector to be of the highest priority due to the suitability of higher yielding biofuel options, followed by land goods transport, shipping and finally aviation. If gaseous fuels are not possible to introduce on a large scale, sectors where liquefied gaseous fuels are suitable become the priority, i.e. goods transport and shipping. The current practise of applying
admixture quotas to sub-sectors of land transport renders a significantly lower climate benefit compared to an overall optimal usage, and a large societal transition is required before aviation biofuels become the climate optimal biomass usage.
The direct importance of land use has thus far not received enough attention in terms of the economics of biofuels from dedicated crops, as well as for the greenhouse gas emissions policy. Biofuels produced from arable land can provide a strong GHG benefit if an expansion of arable land is hindered through redirecting land use, which requires a holistic policy approach.:Abstract ix
Acknowledgments xi
List of Publications xiii
List of Acronyms xv
I Introductory chapters 1
1 Background 3
1.1 Biofuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Technological Change and Modelling . . . . . . . . . . . . . . . . . . . . . . 6
1.3 Aim and objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Methodology 9
2.1 Systems modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Model description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3 Results and discussion 17
3.1 Biofuel techno-economic potential and competitiveness . . . . . . . . . . . . 17
3.2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2.1 Resource base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2.2 Biomass climate benefit in other sectors . . . . . . . . . . . . . . . . 20
3.2.3 Other renewable fuel options . . . . . . . . . . . . . . . . . . . . . . 21
3.2.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.2.5 Applicability of results to other regions . . . . . . . . . . . . . . . . 22
4 Conclusions 25
4.1 Future research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Bibliography 29
Contribution to Appended Papers 33
Curriculum Vitae 35
CONTENTS
II Appended papers 37
1 Competitiveness of advanced and conventional biofuels: Results from
least-cost modelling of biofuel competition in Germany 39
2 Biomass price developments inhibit biofuel investments and research in
Germany: The crucial future role of high yields 51
3 Relative greenhouse gas abatement cost competitiveness of biofuels in
Germany 63
4 Climate optimal deployment of biofuels from crops in Germany 85Biokraftstoffe sind eine erneuerbare Alternative zur Verringerung der Klimaauswirkungen des Verkehrs. Aufgrund der Vielseitigkeit der Biomasse und der Komplexität der Ökonomie und der Auswirkungen sind Biokraftstoffe Teil eines komplexen Systems, das hier aus einer Systemperspektive analysiert wird. Es werden mehrere Modelle entwickelt, um die Wettbewerbsfähigkeit verschiedener biogener Biokraftstoffoptionen als Teil eines Systems unter Verwendung verschiedener wirtschaftlicher und ökologischer Funktionseinheiten zu bewerten. Der Umfang ist auf Deutschland bis 2050 festgelegt.
Die Kapital- und Rohstoffkosten wurden im Vergleich zu herkömmlichen Annahmen auf ein höheres Niveau angepasst. Die verschiedenen Funktionseinheiten führen zu unterschiedlichen Merit Order für die Biokraftstoffoptionen. Die derzeit verwendeten Biokraftstoffe, Raps-Saatgut-Biodiesel und Stärkepflanzen-Bioethanol, erwiesen sich als nicht wettbewerbsfähig, wenn man differenzierte und steigende Rohstoffkosten in Betracht zieht. Fortschrittliche flüssige Kraftstoffe waren nur unter extremen Annahmen wettbewerbsfähig, entgegen den üblichen Erwartungen. Stattdessen dominierte Ethanol auf Zuckerrübenbasis für einen Großteil der Zeitspanne beim Vergleich der Energiekosten, während synthetisches Erdgas (SNG) auf der Basis der Treibhausgasvermeidungskosten wettbewerbsfähig war, insbesondere bei einer schnellen Dekarbonisierung des Strommixes. Mit einer Funktionseinheit zur Reduzierung der Treibhausgasemissionen war Silagemais-basiertes Biomethan die beste Option, wobei SNG bei sehr hohen Anteilen an erneuerbaren Energien der Hintergrundsysteme konvergierte.
Der Wechsel von der derzeitigen Praxis zu ertragreicheren Biokraftstoffoptionen kann die Verringerung pro Landfläche für die Gegenwart verdreifachen und in Zukunft möglicherweise um den Faktor fünf erhöhen. Die Fokussierung auf die Reduzierung von Treibhausgasen pro Ackerfläche führt dazu, dass der Landpersonenverkehr aufgrund der Eignung ertragreicherer Biokraftstoffoptionen, gefolgt von Landverkehr, Schifffahrt und schließlich Luftfahrt, höchste Priorität genießt. Wenn es nicht möglich ist, gasförmige Kraftstoffe in großem Maßstab einzuführen, werden Sektoren, in denen verflüssigte gasförmige Kraftstoffe geeignet sind, zur Priorität, d.h. Güterverkehr und Schifffahrt. Die aktuelle Praxis der Anwendung von Beimischungsquoten für Teilbereiche des Landverkehrs führt zu einem deutlich geringeren Klimanutzen im Vergleich zu einer insgesamt optimalen Nutzung, und es ist ein großer gesellschaftlicher Wandel erforderlich, bevor Biokraftstoffe aus der Luftfahrt zur klimaoptimalen Biomassenutzung werden.
Die direkte Bedeutung der Landnutzung hat bisher nicht genügend Beachtung gefunden, sowohl in Bezug auf die Wirtschaftlichkeit von Biokraftstoffen aus Sonderkulturen als auch in Bezug auf die Treibhausgasemissionen. Biokraftstoffe, die von Anbaubiomasse hergestellt werden, können einen starken Treibhausgasvorteil bieten, wenn eine Ausweitung der Ackerfläche durch eine Neuausrichtung der Landnutzung behindert wird, was einen ganzheitlichen politischen Ansatz erfordert.:Abstract ix
Acknowledgments xi
List of Publications xiii
List of Acronyms xv
I Introductory chapters 1
1 Background 3
1.1 Biofuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Technological Change and Modelling . . . . . . . . . . . . . . . . . . . . . . 6
1.3 Aim and objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Methodology 9
2.1 Systems modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Model description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3 Results and discussion 17
3.1 Biofuel techno-economic potential and competitiveness . . . . . . . . . . . . 17
3.2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2.1 Resource base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2.2 Biomass climate benefit in other sectors . . . . . . . . . . . . . . . . 20
3.2.3 Other renewable fuel options . . . . . . . . . . . . . . . . . . . . . . 21
3.2.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.2.5 Applicability of results to other regions . . . . . . . . . . . . . . . . 22
4 Conclusions 25
4.1 Future research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Bibliography 29
Contribution to Appended Papers 33
Curriculum Vitae 35
CONTENTS
II Appended papers 37
1 Competitiveness of advanced and conventional biofuels: Results from
least-cost modelling of biofuel competition in Germany 39
2 Biomass price developments inhibit biofuel investments and research in
Germany: The crucial future role of high yields 51
3 Relative greenhouse gas abatement cost competitiveness of biofuels in
Germany 63
4 Climate optimal deployment of biofuels from crops in Germany 8
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