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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Methodenhandbuch Stoffstromorientierte Bilanzierung der Klimagaseffekte: Methoden zur Bestimmung von Technologiekennwerten, Gestehungskosten und Klimagaseffekten von Vorhaben im Rahmen des BMU-Förderprogramms „Energetische Biomassenutzung“

Thrän, Daniela, Pfeiffer, Diana 01 August 2022 (has links)
Optimierungen mit mehr als einer Zielgröße haben es in sich – das weiß jeder Forscher und jede Forscherin, die sich mit der Weiterentwicklung von Prozessen und Konzepten beschäftigt hat. Reduktion der Treibhausgasemissionen und Energieeffizienz bei gleichzeitiger Versorgungssicherheit und Wettbewerbsfähigkeit sind die Ziele, denen sich das BMWi-Forschungsnetzwerk Bioenergie im Rahmen des 7. Energieforschungsprogramms verschrieben hat. Um diesem Zielbündel gerecht zu werden, müssen Begrifflichkeiten (z. B. was ist ein nachhaltiges Biomassepotenzial), generelle Bewertungsgrößen (z. B. für die gemeinsame Betrachtung von Treibhausgasreduktion und Energieeffizienz) als auch Erwartungen an die Detailtiefe, also was kann weggelassen werden, ohne das Gesamtergebnis zu verfälschen bzw. zu sehr zu beeinflussen (z. B. bei der Betrachtung von Umwelteffekten) im Vorfeld und projektübergreifend festgelegt werden. Und Verbesserung und Optimierung braucht immer Messgrößen für ihre Bestimmung. Auch hier sind von generellen Fragen bis hin zur spezifischen Festlegung der Systemgrenzen ein Strauß von Einzelfragen aufgeworfen – ohne Aussicht auf zweifelsfreie und allgemeingültige Antworten. In der Summe heißt das: Der Versuch, Bewertungsmethoden zu harmonisieren und einfach und transparent möglichst vielen Forschungsvorhaben verfügbar zu machen, ist risikobehaftet, mühsam und im Ergebnis immer ein Kompromiss. Das hier vorgelegte Methodenhandbuch versteht sich als eben solcher Kompromiss: es bietet Ansatzstellen, die vielfältigen Einzelvorhaben des Forschungsnetzwerkes Bioenergie zusammen zu führen und die Anschlussfähigkeit der Bewertungsergebnisse zu verbessern. Die vorgeschlagenen Dokumentationsvorlagen und Methoden basieren dabei auf dem Stand der Wissenschaft und reichen von der Berichterstattung (wie vorgegangen wurde) bis zur detailliert benannten Berechnungsmethode. Sie beschränken sich auf ausgewählte Fragestellungen und liefern keine vollständige Nachhaltigkeitsbewertung. Die nun 5. Ausgabe ist das Ergebnis eines dreijährigen Diskussionsprozesses, für dessen Unterstützung ich allen Beteiligten danke. Wertvolle Beiträge wurden in Arbeitsgruppen und Workshops des Netzwerks generiert.. Erstmals beziehen die Bewertungsansätze auch die flexible Energiebereitstellung mit in die Betrachtungen ein. Die hier vorgelegte Fassung des Methodenhandbuchs steht nun zur Anwendung zur Verfügung und bildet mit den abgestimmten Referenzsystemen nicht zuletzt auch eine Brücke zur Gesamteinordnung der Forschungsvorhaben und des Netzwerks in das Energieforschungsprogramm der Bundesregierung. Zweifelsohne können die dargestellten Ansätze und Berechnungsverfahren nur einen ersten Aufschlag darstellen, der sowohl wissenschaftlich als auch in der praktischen Anwendung weiterentwickelt werden kann und soll. Für diese und die weiteren Herausforderungen rund um Methodenharmonisierungen ist auch in Zukunft die konstruktive und fruchtbare Zusammenarbeit im Netzwerk unerlässlich. Dahinter stehen unverändert das Ziel und die Notwendigkeit, die energetische Biomassenutzung Schritt für Schritt weiter zu optimieren / It is not an easy task trying to optimise the production of bioenergy with more than one target in mind – every researcher who deals with the development of processes and ideas is well aware of this this. The reduction of greenhouse gas emissions and energy efficiency combined with security of supply and competitiveness are the goals to which the BMWi Bioenergy Research Network has committed itself within the framework of the 7th Energy Research Programme.. To meet this set of goas, concepts (e. g. what is a sustainable biomass potential), general evaluation parameters (e. g. for the joint assessment of greenhouse gas reduction and energy efficiency) as well as expectations of the level of detail, i. e. what can be omitted without distorting the overall result or influencing it too much (e. g. when considering environmental effects) must be defined in advance and across the projects. Furthermore, improvement and optimisation always requires more empirical data to determine the limits of the system. Without these pieces of information the level of uncertainty becomes even more greater making the validity of results more difficult to conclude. The implications of this is that there is a great need to provide transparency and harmonisation amongst evaluation methods. The only means of doing so is by providing information and empirical data for as many research projects as possible. This is an arduous task and in many cases can be fraught with risk for the researcher involved and will no doubt always end in some sort of compromise. This method handbook considers itself to be such a compromise: it provides points of contact which bring together the diverse projects of the Bioenergy Research Network and as such improves the connectivity of the evaluation findings. The suggested method documentations are based on the current state of scientific knowledge and range from qualitative descriptions of methods to detailed calculation methods. They are limited to selected questions and provide no guideline for complete evaluation of sustainability. The 5th edition of the method handbook is the result of a three- year discussion process, for which I would like to thank all those who participated. Valuable contributions were generated in working groups and workshops of the research network. For the first time, the assessment approaches also include flexible energy supply. This version of the method handbook is now ready to be used and through its coordinated reference systems, forms a bridge for the overall classification of the research projects and the research network as part of the federal government’s energy research programme. Without doubt, the approaches and calculation procedures listed here only represent a starting point; from further developments can be based upon, both scientifically and in practical applications. Future constructive and fruitful collaborations within the network are essential for this and other challenges surrounding the harmonisation of methods. All this is still driven by the need and the goal to further optimise, little by little, the use of biomass in energy production.
22

Method handbook material flow-oriented assessment of greenhouse gas effects: Methods for determination of technology indicators, levelized costs of energy and greenhouse gas effects of projects in the funding programme “Biomass energy use”

Thrän, Daniela, Pfeiffer, Diana 02 August 2022 (has links)
This method handbook tries to provide such a compromise: it gives guidance for diverse projects of the programme 'Biomass energy use' and as such improves the connectivity of the evaluation fi ndings. The suggested method documentations are based on the current state of scientifi c knowledge and range from qualitative descriptions of methods to detailed calculation methods. They are limited to selected questions and provide no complete evaluation of sustainability. It is the result of a four-year discussion process, enriched by the project partners of the funding programme. Valuable contribution were generated in working groups and at various workshops. Here the dedication of the working groups 'Biomass Potentials', 'Life-cycle Assessment', 'Thermochemical Gasifi cation' and 'Reference Systems' should be particularly mentioned. This version of the method handbook is now established and through its coordinated reference systems it forms a bridge for the overall classifi cation of the research projects and the funding programme in the framework of the German climate protection discourse. Without doubt, the approaches and calculation procedures listed here only represent a starting point; on which further developments can be based upon, both scientifi cally and in practical applications. Future constructive and fruitful collaborations within the programme are essential for this and other challenges surrounding the harmonisation of methods. All this is still driven by the need and the goal to further optimise, little by little, the use of biomass in energy production.
23

Global warming without global mean precipitation increase?

Salzmann, Marc 19 July 2016 (has links) (PDF)
Global climate models simulate a robust increase of global mean precipitation of about 1.5 to 2% per Kelvin surface warming in response to greenhouse gas (GHG) forcing.Here, it is shown that the sensitivity to aerosol cooling is robust as well, albeit roughly twice as large. This larger sensitivity is consistent with energy budget arguments. At the same time, it is still considerably lower than the 6.5 to 7% K−1 decrease of the water vapor concentration with cooling from anthropogenic aerosol because the water vapor radiative feedback lowers the hydrological sensitivity to anthropogenic forcings. When GHG and aerosol forcings are combined, the climate models with a realistic 20th century warming indicate that the globa lmean precipitation increase due to GHG warming has, until recently, been completely masked by aerosol drying. This explains the apparent lack of sensitivity of the global mean precipitation to the net global warming recently found in observations. As the importance of GHG warming increases in the future, a clear signal will emerge.
24

Restricting greenhouse gas emissions : economic implications for India /

Gupta, Manish. January 2006 (has links) (PDF)
Diss.--New Delhi Jawaharlal Nehru Univ.
25

Entwicklung eines miniaturisierten ballongetragenen Diodenlaser-Spektrometers zur Messung von stratosphärischen Methan- und Wasserdampfkonzentrationen

Zimmermann, Rainer. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2003--Heidelberg.
26

A quantitative analysis of the biological pump in the oligotrophic subtropical North Atlantic

Dietze, Heiner. Unknown Date (has links) (PDF)
University, Diss., 2004--Kiel.
27

Global warming without global mean precipitation increase?

Salzmann, Marc January 2016 (has links)
Global climate models simulate a robust increase of global mean precipitation of about 1.5 to 2% per Kelvin surface warming in response to greenhouse gas (GHG) forcing.Here, it is shown that the sensitivity to aerosol cooling is robust as well, albeit roughly twice as large. This larger sensitivity is consistent with energy budget arguments. At the same time, it is still considerably lower than the 6.5 to 7% K−1 decrease of the water vapor concentration with cooling from anthropogenic aerosol because the water vapor radiative feedback lowers the hydrological sensitivity to anthropogenic forcings. When GHG and aerosol forcings are combined, the climate models with a realistic 20th century warming indicate that the globa lmean precipitation increase due to GHG warming has, until recently, been completely masked by aerosol drying. This explains the apparent lack of sensitivity of the global mean precipitation to the net global warming recently found in observations. As the importance of GHG warming increases in the future, a clear signal will emerge.
28

Luftschadstoff- und Treibhausgasemissionen in Sachsen: Jahresbericht 2012

Schreiber, Ute 10 November 2016 (has links)
Der Bericht informiert über die Emissionssituation 2012 im Freistaat Sachsen. Betrachtet werden die anthropogen verursachten Emissionen von Treibhausgasen, klassischen sowie persistenten organischen Luftschadstoffen und Schwermetallen sowie deren Verursacher. Dazu gehören insbesondere Groß- und Kleinfeuerungsanlagen und emissionserklärungspflichtige Anlagen aus Industrie, Verkehr und Landwirtschaft. Die Auswertung erfolgt nach dem Prinzip der Quellenbilanz, d. h. die Emissionen werden dort erfasst, wo sie entstehen, unabhängig vom Ort des Endverbrauchs.
29

Minderung von Treibhausgas-Emissionen der Landwirtschaft

von Buttlar, Christine, Freitag, Thomas, Rebbe, Falk, Zorn, Stefan 26 March 2015 (has links) (PDF)
In dem Bericht werden der Treibhausgas (THG)-Ausstoß der sächsischen Landwirtschaft, die bisher erbrachten Klimaschutzleistungen und die Minderungspotenziale bis zum Jahr 2020 dargestellt. Für den gewählten Bilanzkreis hat die sächsische Landwirtschaft ca. 7,6 % zum THG-Ausstoß in Sachsen beigetragen. Im Vergleich zum Jahr 2000 konnte der THG-Ausstoß um ca. 5 % vermindert werden. Bis zum Jahr 2020 könnte ein THG-Minderungspotenzial von weiteren etwa 5 % erschlossen werden. Die Veröffentlichung richtet sich vorrangig an Fachleute aus der Landwirtschaft, aber auch an die Verbraucher, die ebenfalls einen Beitrag zur Minderung des THG-Ausstoßes leisten können.
30

The effect of turning frequency on methane generation during composting of anaerobic digestion material / Ảnh hưởng của sự đảo trộn đến quá trình sinh khí mê tan trong đống ủ phân compost của chất thải từ hầm ủ biogas

Nguyen, Thanh Phong, Cuhls, Carsten 24 August 2017 (has links) (PDF)
Methane (CH4) is included in the direct greenhouse gases listed in the Kyoto protocol. The composting of anaerobic digestion (henceforth AD) material is a source of CH4. CH4 is the major contributor to overall CO2 emissions. Therefore, it is important to know the formation of this gas from different stages and substrates of the composting process. This study investigated CH4, CO2 and O2 profiles in two open-windrows in composting plants treating AD material. One composting windrow was turned one a week; whereas another was turned twice a week using a special windrow turner. To assess the gaseous formation in the composting windrows, CH4, CO2 and O2 volume concentrations were measured at different depths. Active aeration has been considered as a method to reduce CH4 generation during composting. However, our results showed that frequent turned windrow generated more CH4 than less turned windrow. The highest CH4 concentrations were found at a depth of 1 m, and were 45% and 37% for 2 times a week turned windrow and 1 time a week turned windrow respectively. Gas concentrations of CH4, O2 and CO2 in both windrows differed. Concentrations of CO2 and CH4 increased with depth, whereas concentration of O2 decreased from the surface to the lowest point. The O2 and CO2 are important factors in determining whether the windrows are anaerobic or aerobic. / Khí mê tan (CH4) là một trong những khí nhà kính được liệt kê trong nghị định thư Kyoto. Quá trình ủ phân compost từ các chất thải của hầm ủ biogas là nguồn phát sinh loại khí này. Khí mê tan đóng góp chủ yếu trong tổng lượng khí nhà kính phát thải vào khí quyển. Do đó, những hiểu biết về quá trình hình thành loại khí này trong các giai đoạn khác nhau của quá trình ủ phân compost từ chất thải hầm ủ biogas là rất quan trọng. Nghiên cứu này tìm hiểu sự phát thải khí CH4, CO2 và O2 trong 2 luống ủ ngoài trời tại các nhà máy xử lý rác thải hữu cơ bằng phương pháp kỵ khí. Luống ủ 1 được đảo trộn một lần một tuần trong khi luống ủ số 2 được đảo trộn 2 lần 1 tuần. Để đo đạc lượng khí phát thải từ các luống ủ phân compost, nồng độ các khí CH4, CO2 và O2 được đo ở các độ sâu khác nhau. Việc cung cấp khí oxy được coi như là một biện pháp để làm giảm sự hình thành khí mê tan. Tuy nhiên, kết quả đo đạc của chúng tôi chứng minh rằng việc đảo trộn thường xuyên phát thải nhiều khí mê tan hơn ít đảo trộn. Nồng độ khí mê tan cao nhất 45% và 37% đo được ở khoảng cách 1m từ bề mặt đối với luống ủ đảo trộn hai lần và một lần. Nồng độ các khí CH4, CO2 và O2 khác nhau ở hai luống trong thí nghiệm. Nồng độ khí CH4 và CO2 tăng theo độ sâu, trong khi O2 giảm theo độ sâu. Nồng độ khí CO2 và O2 đóng vai trò quyết định luống ủ được cung cấp đủ oxy cho quá trình phân hủy hiếu khí hay không.

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