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Pollution by Urban Submarine Groundwater Discharge from the Jepara Coastal Region and Its Implications for Local Water Management
Get PDFSubmarine groundwater discharge (SGD) is known to transport terrestrial nutrients and other potential pollutants to coastal areas around the world. However, SGD studies in tropical developing regions, such as Southeast Asia, are scarce, even though this area is hypothesized to be an SGD hotspot due to favorable meteorological and hydrological conditions. Jepara, a coastal city in northern Java, is characterized by a number of environmental and anthropogenic steering factors (e.g., precipitation rates, volcanic geology, coastal population density, and urban land use) that may support the notion of considerable SGD rates and its associated pollutant fluxes. Therefore, this thesis investigates SGD volumetric estimation with nutrient and microbial community composition to analyze the scale of land-based pollutants delivered by SGD to the nearshore water. Additionally, environmental and health impacts of SGD and suggested coastal water management in this region are also discussed. 222Rn was employed as a groundwater tracer in the coastal water to estimate SGD rates. Spatial and temporal 222Rn surveys were conducted in the estuaries and along the coastline of Jepara. The results indicate that terrestrial groundwater was discharged more at the estuaries than at the coastline. Fresh groundwater comprised up to 42% of total river discharge and 40% of total SGD at the coastline. SGD in this area was driven primarily by tidal pumping, with additional hydraulic gradient-driven fresh groundwater discharge at low tide. A combination of estuarine and coastal SGD results in total volumetric SGD rates of 6.6 x 105 m3 d-1. SGD rates in this area were comparable with those of other volcanic SGD studies and were higher than those in other sub-tropical or temperate region studies. SGD was confirmed to deliver terrestrial dissolved inorganic nitrogen (DIN) and dissolved silica (DSi) to the coastal system, and it also potentially acted as one of the landa ocean delivery pathways for fecal indicators and bacterial pathogens. It was also found that salinity and temperature were the most determinant variables that shaped microbial community composition in an SGD cross section. Nutrient and land-use analyses suggest that high nutrient pools in the coastal hydrological system originated from human activities, i.e., agriculture, livestock, and the sewage system. This result was also supported by microbial community analysis, where identification of fecal indicators and potential pathogens in the SGD compartment confirmed the occurrence of biological contamination. Nutrient levels and potential pathogens lead to coastal eutrophication and waterborne illnesses, which were reported from this area. From these observations, it was concluded that suitable coastal water pollution prevention at this study site should include terrestrial nitrogen containment along the riverbank and estuaries (e.g., a constructed wetland or riparian zones) and the development of a sewage system and a centralized wastewater treatment plant. Overall, this thesis shows a significant amount of contaminant discharge in the coastal area via SGD due to a combination of both environmental and anthropogenic factors. Moreover, it can be inferred that a combination of interdisciplinary geoscience research (e.g., hydrosphere, biosphere, anthroposphere) can provide a deeper understanding and assessment of SGD in a specific environment. Even though it is a local study, the methodology and results of this thesis can be replicated and thus provide assistance in other coastal urban cities in tropical regions and hence facilitate better evaluation and monitoring of tropical coastal water ecosystems in the future
Nachhaltigkeit, Resilienz und Organisationale Achtsamkeit als Bausteine einer umfassenden Ressourcenorientierung in der Managementlehre
Get PDFCompanies face three existential challenges: The scarcity of resources, the uncertainty of the environment and the overload of employees. To ensure their survival, companies must maintain their economic substance, secure their relationships with resource suppliers, develop flexible resilience and strengthen their employees. Given the absolute limitations of resources, it is clear that these measures go hand in hand with ongoing resource management dilemmas. The simultaneous management of economic challenges and dilemmas is the central task of management. Existing management approaches do not provide sufficient knowledge to do justice to this. This thesis examines resource-oriented management approaches with a view to their underlying relationship structures in order to draw up statements about the possibilities and limits of a comprehensive resource-oriented management. The results show that companies operate in a field of tension between health maintenance and profit generation. In order to bring this dual concept of success into strategic harmony, the mindful awareness of the company, the environment and resource dependencies is the basis
Business Cycles and Consumer Behavior
Get PDFThis cumulative dissertation contains three empirical research papers. In paper I, the author investigates the moderating influence of consumer confidence on the relationship between electronic word of mouth (eWOM) and sales. Using longitudinal product level data, the author demonstrates the changing effectiveness of different eWOM characteristics for consumersa decision making process in the light of varying economic conditions. Paper II turns the attention towards consumer purchase behavior in the fast moving consumer goods (FMCG) context. Using individual transaction data on the household level, the author reveals seven distinct shopping strategies and shows, how household switch shopping strategies when micro- and macroeconomic conditions change. Paper III investigates the impact of economic expansions and contractions on consumersa postpurchase satisfaction judgement expressed in the online opinion section of a retailer website. Using longitudinal data on the product level, the author demonstrates the distinct effects of economic expansions and contractions on consumersa opinion expressions in online environments
Dynamic Inverse Problems for Wave Phenomena
Get PDFIn this work, we deal with second-order hyperbolic partial differential equations that include time- and space-dependent coefficients, and the inverse problems of identifying these coefficients based on their effect on the equationa s solution. We present the needed theory for such equations, including some regularity results for their solution. This allows to state and analyze the inverse problems, even in an abstract setting where time-dependent operators are sought. Subsequently, we show how these results can be applied to actual partial differential equations. We give a detailed demonstration in the context of the acoustic wave equation. Our results allow the identification of a time- and space-dependent wave speed and mass density in such a setting, and we give an extensive numerical analysis for this case. We also outline how the abstract framework can be applied to other equations, like simple models for electromagnetic waves
Non-Renewable Resources in a Ramsey Economy with Subsistence Consumption, Human and Physical Capital Accumulation: A full Characterization
Get PDFWe investigate the question on how to use a non-renewable resources efficiently in the presence of a minimum subsistence level of consumption. In our model, households are characterized by Stone-Geary preferences and output is Cobb-Douglas using physical and human capital as well as resources as input factors. This setup gives rise to a six dimensional dynamic system with three control and three state variables. Despite this complexity, it is shown that a closed form solution exists in terms of the Gaussian hypergeometric function. The closed form solution allows us to calibrate the model to the situation of 108 countries using data from the World Bank on countries' endowments with physical capital and natural resources. We are able to quantify the implications of observed capital stocks for the growth perspective of each country. In particular, we analyze whether a level of subsistence consumption equivalent to the World Bank's poverty lines can be accomplished. Our calibration results also shed some light on what has been termed the resource curse
Empirische Methode zur schnellen Charakterisierung von Wärmebehandlungszuständen hochfester Aluminiumlegierungen
Get PDFHeat treatment is an essential process step in the final adjustment of the mechanical properties of the hardenable aluminium alloys. The effects of the precipitation hardening parameters on the mechanical properties of various aluminium alloys have been experimentally investigated, but the results are often incomplete or restricted to sub-steps of the heat treatment. In this work a time and cost efficient empirical method for predicting the mechanical properties of heat-treatable aluminum alloys on the basis of the precipitation-hardening conditions of the process steps solution annealing, quenching and ageing was developed. For the model, both the highest possible calculation accuracy and the speed of the model generation are important. Furthermore, the transfer of the method to components with different thicknesses and micro components was investigated. With this method it is possible to quickly calculate the mechanical properties of the known aluminium alloys as well as to quickly characterize of new alloys for the application in material development
Entwicklung robuster Prognosen für ein Energiemanagementsystem anhand datenbasierter Modellierungsverfahren unter Berücksichtigung von Unsicherheiten
Get PDFThe aim of this thesis is the development of robust and highly automated day ahead forecast methods for generation plants and storages. These form the basis for a transferable energy management system for agricultural companies. Data-based methods are formulated for both a deterministic and a probabilistic forecast. From a mathematical point of view, they only differ in the objective function of the underlying optimization problem. With a polynomial ansatz function deterministic and probabilistic day ahead forecasts for a photovoltaic plant, a wind plant and a battery storage are computed. Due to efficient optimization methods, both the training and the update of the models can be performed with significantly small computation times. In order to determine the achievable accuracy of the forecasts, detailed analyses are carried out on the basis of long-term data. This results in deterministic generation forecasts with an nRMSE of 12 % to 13 % and state of charge forecasts of a battery storage with an nRMSE of approximately 2 %. The comparison to other models in two benchmarks has shown that they lead to similar results. For the probabilistic models, other criteria are used to evaluate the quality of the forecast. The proposed quantile regression method leads to highly reliable forecasts of the generation plants, whereas the probabilistic battery storage forecast is less reliable due to the iterative evaluation of the dynamic model over the test horizon. Based on the general formulation of the forecast methods as optimization problems, the sensitivity analysis of the NLP-solver WORHP can be used to detect the most important input values for the generation forecast. In combination with the implemented model update, this results in a highly automated forecast. After a training duration of 20 days, these forecasts show similar results compared to the analysis of the long-term data. Again, this cannot be realized for the battery storage with the proposed iterative model evaluation of a static model. The forecasting models of the various components of the energy management system are finally combined in a simulation environment. Herein, the potential benefit of probabilistic generation forecasts for decisions in an energy management system is shown
Innovation industrienaher Dienstleistungen : eine fallstudienbasierte Analyse dynamischer Fähigkeiten und des unterstützenden IT-Einsatzes
Get PDFThe thesis deals with the innovation of industrial services. Starting from the dynamic capability view, the innovation of services is understood as a dynamic capability, which enables companies to sense opportunities and threats in the market, seize them and finally transform their resource base accordingly. The aim of this research is the empirical description of the innovation of industrial services, from which the contextualized characteristics, the roots of dynamic capabilities as well as the role of IT are derived. For this purpose, the dynamic capabilities are investigated in comparative case studies at the level of microfoundations. The focus is particularly on structures, processes, procedures and systems as well as on individuals underlying the dynamic capabilities. This research provides an overview of concrete innovation practices, causal factors for different characteristics of dynamic capabilities, and insights into the role and function of IT in service innovation
Skateboarding als neue Disziplin bei den Olympischen Sommerspielen 2020 in Tokio : eine Analyse der Chancen und Risiken für den Freizeitsport Skateboarding
Get PDFDie vorliegende Arbeit befasst sich mit der Integration des Freizeitsports und der jugendlichen Bewegungskultur Skateboarding in die Olympischen Spiele 2020 in Tokio. Eine Analyse von Sekundärliteratur führt dabei zu der primären Erkenntnis, dass die Phänomene Skateboarding und Olympia nicht vollständig vereinbar sind, allerdings durch den Beschluss 2016 eine Integration nicht mehr abzuwenden ist. Aus diesem Grund ist es von Bedeutung, die Umsetzung bestmöglich zu gestalten und die Identität der Szene zu wahren. Mit Hilfe einer eigens durchgeführten empirischen Untersuchung in Form von teilstandardisierten Experteninterviews werden die Chancen und Risiken für die Skater-Szene, für Olympia, für die Wirtschaft und die Vereine, die sich durch die Aufnahme der Sportart in die Spiele ergeben, herausgestellt. Dabei wird zum einen deutlich, dass die Zusammenführung der beiden Phänomene einige Chancen wie beispielsweise die Verjüngung Olympias und die externe und interne Verbreitung des Skateboarding mit sich bringt. Allerdings auch Risiken, wie zum Beispiel eine Entwicklung in Richtung Versportlichung und damit einhergehend ein Freiheitsverlust, Fremdbestimmung und Standardisierung des Skateboarding erkennbar sind, die es gilt abzuschwächen. Auf Grundlage der Chancen und Risiken werden Handlungsempfehlungen für die unterschiedlichen beteiligten Akteure verfasst, die zu einer bestmöglichen Integration der Sportart bei Olympia beitragen sollen
On the Design of Actuator and Control Systems in Early Development Stages
Get PDFVehicle development faces new challenges due to the increasing requirements on vehicle performance, e.g., on ride, comfort and safety. Adding mechatronic systems to the chassis helps to reach more ambitious design goals, however, it also adds to the complexity of the design process. The number of design variables increases significantly: in addition to the mechanical chassis, actuators of mechatronic systems and control logic parameters affect the overall vehicle performance. The complex interaction between many design variables poses a particular challenge. Engineers need to make important design decisions in early development stages, typically about the mechanical chassis, without knowing the final design, in particular the detail parameters of mechatronic systems