500 Naturwissenschaften und Mathematik
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- Fakultät 12 / Institut für Technologie und Ressourcenmanagement in den Tropen und Subtropen (28)
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Die Einzelfadenverklebung zur Rissschließung in Leinwandbildträgern stellt ein bedeutendes Forschungsfeld dar, dem sich diese Arbeit widmet:
Erstmalig wurden in einem gemeinsamen Kontext uniaxiale Zugprüfungen an freien
Klebstofffilmen, verklebtem Garn und Gewebestreifen neben biaxialen Zugversuchen und multiaxialen Berstdruckprüfungen an Gewebeproben aus Leinen gegenübergestellt. Dazu wurden Rissverklebungen mit einer Auswahl unterschiedlicher Kunstharzdispersionen und Störleim-Modifikationen in überlappenden bzw. Stoß-auf-Stoß-Verbindungen mit und ohne Fadenbrücken angefertigt.
Ziel der Untersuchung war es, die einzelnen Einflussfaktoren bei den verschiedenen Versuchsreihen zu vergleichen und eine geeignete Prüfsystematik für die Klebstoffbewertung zur Rissbehandlung in textilen Bildträgern zu entwickeln.
Es zeigte sich, dass nur die Prüfung mehrerer verklebter Fäden im Gewebeverbund als langfristig sinnvoller Prüfaufbau verfolgt werden sollte. Im Zuge der Verklebungsbetrachtung konnten zudem vielversprechende Klebstoffe und -modifikationen gefunden sowie der zusätzlich verfestigende Effekt von Fadenbrücken an Stoß-auf-Stoß-Verbindungen belegt werden.
Jordan is deemed as one of the least water-endowed regions in the world. The acute water shortage, accompanied with changing climatic conditions have necessitated the increasing use of treated wastewater (TWW), predominantly in irrigated agriculture sector. This is especially true with the upper Zarqa River. The ample supply of TWW resources can be found there; paradoxically, the practical implementation of TWW reuse is hindered by the enforcement of irrigation water quality standard, compounding pressure on the dwindling groundwater resources. In light of the large potential source of TWW, this study aims to supply knowledge on maximizing the safe reuse of TWW while minimizing the environmental impacts within the local environment of the upper Zarqa River. A SWOT analysis was conducted to identify the strengths, weaknesses, opportunities, and threats of TWW reuse for agriculture in the local context. In recognition of the projected growth in the treated effluent to more than 135 MCM in the coming ten years, and how it would affect the water use on the study region, several plausible development scenarios were proposed based on expected developments on the ground. Considering the vital role of TWW in sustaining multiple ecosystem services, this study addresses the need to review current standard, encourages managed aquifer recharge with TWW, recommends crops type modification, and enhances knowledge on suitable practices at farm level. Each of these factors is needed in order to deliver a range of ecosystem services to sustain the local rural communities and to advance them in the face of profound challenges, thereby leading to its stability and increased productivity.
Das Ziel der vorliegenden Masterthesis ist es, einen Überblick der verschiedenen Datenbanktypen und Leistungsanalysen zu geben. Die vergleichende Literaturstudie beschäftigt sich mit einem jungen Forschungsfeld und betrachtet insbesondere nichtrelationale NoSQL-Datenbanken, welche in den letzten Jahren immer beliebter geworden sind und einige Vorteile gegenüber relationalen Datenbanken aufweisen. Doch was können die konkreten Datenbankimplementierungen bei unterschiedliche Datenmodellen leisten und welcher Testaufbau bietet sich bei welchen Einsatzanforderungen an? Zu Anfang definiert diese Arbeit Kriterien zur Bewertung von Leistung und untersucht experimentelle Vorgehensweise verschiedener Forscher. Ein wichtiger Fokus liegt darauf, die Vergleichbarkeit der Messmethoden und Ergebnisse einzuschätzen und zu gewährleisten. Neben dem methodischen Vorgehen wird mit dem YCSB-Framework ein wichtiges Werkzeug besprochen, mit dem Leistungsmessungen in NoSQL-Datenbanken implementiert werden können.
Amboseli-Tsavo Ecosystem is a unique landscape in Kenya’s semi-arid rangelands to the border of Tanzania. It is characterized by high abundances of wildlife which frequently disperses between three National Parks, namely Amboseli, Tsavo West and Chyulu Hills. Due to an increased population and a land-use change from prior nomadic pastoralism to sedentary farming activities, the land became highly fragmented and transformed into a human-dominated area. Increasingly wildlife migration routes are becoming blocked, leading to isolation of the National Parks and multiplied human-wildlife conflicts. The African elephant (Loxodonta africana) is sadly famous as the most common conflict animal causing damage to properties, cropland and injuring or killing livestock and, in the worst case, people. However, elephants are at the same time a flagship species and represent the backbone for tourism activities around Amboseli. Therefore, the elephant is both a very valuable and problematic asset in the area. Unfortunately, wildlife conservation practices over the last decades, favoring animals over humans, have led to a negative perception of wildlife among the population in the ecosystem which challenges appropriate conservation mechanisms.
To maintain the tourism attraction of viewing elephants and to minimise the conflicts between local communities and animals, migration routes should remain open. The concept of landscape connectivity ensures biodiversity conservation, particularly for far-distance migration animals such as elephants. The elephant was therefore chosen as a keystone species in this study on which the analysis is based.
Using a least-cost path analysis (LCP) in ArcGIS, “cheapest” travel routes of Loxodonta africana between the three National Parks were identified. Factors included were selected and weighted by information gathered in expert interviews. Satellite imagery were classified using ESA SNAP toolbox to obtain vegetation covers and waterbodies for two different seasons (dry and wet), aiming to illustrate the temporal variability of potential connectivity paths. Additionally, key informant interviews and interviews of Group Ranch members around Amboseli National Park were conducted to gather information regarding the current state of management in the ecosystem and perceptions about wildlife management. A subsequent SWOT Analysis on three optimum routes obtained through LCP, takes the social-political factors and information obtained into account to discuss the different options for their conflict solving potential.
On the one hand, recommendations resulting from this study identify possible elephant migration routes that should be maintained by using a participatory conservation approach to secure landscape connectivity in long-term. On the other hand, management recommendations include a design for improved relationships between Group Ranch members and the responsible governmental institutions by equally distributing benefits, implementing financial benefits and establishing a functioning and adequate compensation scheme. By ensuring peoples’ active participation in conservation and wildlife management, a more positive attitude towards wildlife might be induced, which will positively influence the wildlife conflict in long run.
This thesis presents the perspective and basis for modeling of retail electricity price components in Germany. Detailed Python models are developed to provide predictions for yearly development of average network charges, EEG, StromNEV-19 and KWK surcharges for the period 2015-2035. For network charges and EEG surcharge, scenario-B (2035) from NEP2015 has been chosen as the model scenario. For KWK surcharge, the 2025 KWK share target, set by KWKG-2016, has been chosen as the model scenario. Individual component model results are validated against available academic literature and institutional reports. Model results for EEG surcharge, indicate an increasing yearly EEG costs till 2024, after which the expiring EEG plants of past will unburden the related high costs and EEG surcharge will drop but still be around 99% of 2015 level in 2035. Model results for network charges indicate a consistently increasing yearly trend owing to high grid investments needed for reaching the target RE share of 57%. KWK model results also indicate a growing KWK surcharge until 2020 which then would remain stagnant at that level onwards. All model results are collected under three consumption categories, namely, households, privileged and nonprivileged industries. The final results indicate that the average German household will face an overall increase of around 3.37 Cents/kWh in retail electricity prices (excluding VAT) till 2028, after which the retail prices will drop a little due to dropping EEG surcharge. The similar but slightly reduced trend can be seen for nonprivileged industrial consumption. The increment effect, however, is only minute for privileged industrial consumption due to high exemptions in EEG & KWK surcharges and reduced individual network charges.
For sustainable climate, an exponential growth in renewable heating and cooling is compulsory to reduce consumption of the fossil fuels for production of heat. An essential step from European Commission as an introduction of the strategy for renewable heat has
given a platform to the solar thermal market to tap the highest possible potential. To grab the opportunity given, capacity of the production is to be increased as well as reduction in cost of solar thermal product is to be achieved by any suitable alternate means. Polymer
based hybrid collector, named as OPVT collector, is the innovation from Fraunhofer Institute of Solar Energy Systems to break the road blocks for the solar thermal market. A polymer solar cell and a polymer solar thermal collector, both, technologies have tendency
of high initial investments and extremely low running cost in business. The aims of this study were to develop a calculation tool for determination of production cost of different OPVT collector concepts and evaluate their potential with reference to market size. The tool was expected to be uniform for all possible concepts of OPVT collector and flexible in
usage during the early stage of technological development. In this study, “Microsoft Excel” software based calculation tool is developed for estimation of production cost for different concepts. A Car washing station for water based OPVT collector and a bus station for air based OPVT collector are found be most suitable for start-up of the business. The analysis of results has highlighted that the minimum cost of OPVT collector can be referenced as its material cost. The OPVT collector business has huge potential and
possibility of early break-even point in the
production. As production costs are sensitive to
material costs, input values to the tool must be accurate. Presence of dominance of the material cost
is due to high cost of OPV. In industry, OPV is still being considered as the technological product instead the commodity product. This market potential study for
OPVT collector technology has been the important step in giving the confidence to solar thermal, polymer and plastic processing industries for business investment.
Keywords – OPVT collector, production cost, calculation tool, market size
In Sierra Leone, at the moment 10 out of the total 14 districts are faced with the problem of large-scale land investments for industrial agriculture (oil palm, sugarcane…). The production is mainly for the local, regional and world market. There are quite many of these investments in the planning stage, while some are extending their operations by taking more land from communities or are already at the production stage. Studies and media reports have claimed a number of negative impacts felt in communities hosting these companies, ranging from loss of land, food insecurity, increase in poverty to loss of livelihoods, environmental degradation as well as social and cultural problems. The goal of this thesis is to examine the impacts of the operations of “Socfin Agriculture Company” on food security of local communities in Malen Chiefdom, Pujehun District of Sierra Leone.
Both quantitative and qualitative research methods are used for data collection, analyses, and interpretation of results. The research uses household income and expenditure to compare household food security before and after the start of the company’s operations. It examines consequences of community’s loss of land to support household food production versus casual wage earn from employment created by the company to meet household food security.
The results show a loss of household’s income sources and a significant decrease in households’ income. Households’ food crop production has reduced accompanied by a complete loss of cash crop farming. Households affected by the operations of the company have lost access to land and other natural resources that support food production. Furthermore, the company employs very few people in comparison to the total population of affected communities. Calculation of total wage earn from employment by the company cannot meet the staple food (rice) needs of the households. Also, households claimed a host of unfilled promises made by the company and national government at the onset of the operations of the company.
In conclusion, household food production is the most significant determinant for household food security, with regards to food availability, accessibility, utilization and stability of supply. Therefore, national government should carefully study and develop a framework that addresses food security of households impacted by the operations of the rapidly growing large-scale land investment companies and ensure a fair share of the local community in the economic development of the country and suggesting ways of improving access rights in the context of tenure.
Carbon Sequestration under different land uses and soils in the State of Quintana Roo, Mexico
(2017)
Rising in global temperature is evidently related to atmospheric carbon dioxide (CO2) and methane (CH4) concentrations; this has become an environmental problem. The use of renewable energy, the development of eco-friendly merchandise and the enforcement of biomass management have been proposed to mitigate the issue. In the ecosphere, the pedosphere stores 1,500 to 2,500 PgC, which is four times more than the carbon stored in biomass; hence, it is very important to carry out soil carbon studies because of more long-term stability of such storage. In the study, soil carbon quantification was applied to the entire state of Quintana Roo, using a purpose oriented sampling, to observe the dynamic between land uses and soils, relating all relevant characteristics and properties of the landscape. To study the carbon content stored in soils, total carbon was estimated through loss-on-ignition, organic carbon by Walkley-Black method and inorganic carbon by calcium carbonate determination. The result portrays that the coastal dune vegetation-Arenosol (1,256 Mg C ha-1) is the combination with the highest soil carbon density, while Leptosol is the soil type with the highest storage capacity (852 MtC). Consequently, the soil carbon storage not only relates to soil properties but also associates with the surface area occupied by the specific soil type. In addition, the characteristics of the landscape play an important role in the storage of soil carbon. Due to that, soil carbon storage can be explained by biogeomorphoedaphic factors.
The Highland Plateau region, in San Luis Potosí, involves particular dynamics and needs from those presented within the rest of the state; its culture, vocation, mineral resources and territory, converge to give rise to a unique and particular region. The connectivity within the region has been decisive for its development, since two of the largest and most important national roads in go through this territory.
Despite comprehending about a half of the state's territory, this region has not managed to truly influence the state statistics neither economically nor socially; on the contrary, the employment rate has significantly decreased significantly, and also its population number.
Accordingly, this research aims to analyze the connectivity system within this region to strengthen and complement the development tools of these communities in a sustainable manner and, in this way, increase the welfare of the Highland Plateau population.
Throughout this investigation, it will be possible to understand how the location of this physical network, as well as for the use of resources for the satisfaction of the inhabitants, has been reflected in the communities within this region. Likewise, the statements made by state directors in charge of the economy, road network and social development within the region, will be studied. These statements will also be combined with a “functional grid analysis”, the connectivity between communities and their basic needs.
Policy measures are essential tools for the transition from fossil fuels to renewable energy sources in the electricity generation. Feed-in tariffs (FITs) are the most used policy for support of renewable technologies globally. Nevertheless, Ecuador phased-out FITs in 2016 and adopted auctions in 2015. Ecuador’s implementation of auctions reflects an approach with little relation to practices in other countries and without a technology-specific design. On the other hand, Germany demonstrates a long trajectory in policy-making with vast experience in FITs. Moreover, in 2017 Germany adopted auctions as the official policy to support renewable projects with a scope larger than 750 kW. However, FITs are still in use and complement auctions.
This thesis analyses and compares the country-specific contexts where these policies are implemented through the lens of a multi-level perspective framework. As a result, the most important success factors in Germany have been identified: long-term planning, institutional continuity, legislative stability and principally an actively participating society, which is environmentally aware. Obstacles for the transition in Ecuador are institutional discontinuity, legislative inconsistency, the lack of long-term planning and absence of society as actors of the transition. Due to Germany’s pioneering role plus the successful growth of renewable sources during the last twenty years, their policy implementations appear desirable to adopt in other contexts. Therefore, a prospective transferability of the auction policy from Germany to Ecuador is additionally analyzed.