Mobility and removal of nitrate in heterogeneous Eocene aquifers

n a study of the principles of lateral and vertical nitrate mobility and removal in unconfined heterogeneous fine sandy Eocene aquifers by long-term observation, no significant nitrate reduction could be observed over short distances (90 m) in the lateral flow direction. Decreasing oxygen contents and limited flow velocity in a downward direction (caused by clay lenses and layers) resulted in a more efficient but incomplete nitrate removal with increasing depth. Chemo-organotrophic and chemo-lithotrophic denitrification coexist in the aquifers. Recharge input of organic matter and the reactivity of sedimentary organic sources, as well as the amounts of pyrite and Fe2+-bearing minerals, control which microbiologically catalysed process finally occurs. Sharp boundaries between different redox zones do not exist due to locally changing availability of organic and inorganic electron donors used for nitrate reduction. Furthermore, preferential flow paths result in a wide spread occurrence of low concentrations of nitrate below the main denitrification zone

Exploiting the potential for services offshoring: Evidence from German firms

Services offshoring is on the rise. Due to recent innovations in communication technologies, many services that used to be non-tradable can be delivered from distance today. Still, German services imports have grown much slower than exports over the past decades, indicating under-exploitation of the potential for services offshoring. To understand this development, the paper uses a newly combined dataset on German firms' services trade, balance sheets, and foreign affiliates during 2001-2012. Estimation of a firm-level gravity model confirms that more productive firms offshore more, reveals complementarities between services imports and exports, and points towards the importance of intra-firm services trade. The paper establishes that the level of services offshoring is lower in industries with greater offshoring potentials, as captured by their task compositions, but offshoring growth tends to be higher there. These findings indicate that there exists a sizeable potential for services offshoring due to remaining trade barriers, which is yet to be exploited

Hat Globalisierung zu Kreditmarktderegulierung geführt?

Im Zeitraum von 1970–2010 sind sowohl die Globalisierung als auch die Kreditmarktderegulierung stark vorangeschritten. In einer neuen Studie wurde untersucht, ob diese beiden Entwicklungen zusammenhängen und die Globalisierung zu einer Kreditmarktderegulierung geführt hat. Die Analyse kann den scheinbar offensichtlichen Zusammenhang zwischen der Globalisierung und der Kreditmarktderegulierung nicht auf einen kausalen Effekt zurückführen. Zumindest lässt sich ein solcher Effekt mit geeigneten Methoden in den verfügbaren Daten statistisch nicht nachweisen

Service Offshoring and Firm Employment

Major technological advances have recently spurred a new wave of offshoring in services, which used to be non-tradable. Should service workers in developed countries worry about their jobs? Trade theory has given a nuanced answer to this question, suggesting that efficiency gains from offshoring may counteract direct job losses, which leaves the predicted net effect ambiguous. This paper investigates the employment effects of service offshoring in a newly combined and exceptionally detailed panel dataset, covering almost the entire universe of German firms’ service imports over the years 2002-2013. It exploits firm-specific export supply shocks by partner countries and service types as an instrumental variable to find that service offshoring has increased firm employment. In line with the canonical trade in tasks model, the employment gains are greater in firms with higher initial levels of service offshoring

A System Architecture-based Model for Planning Iterative Development Processes: General Model Formulation and Analysis of Special Cases

The development process for complex system is typically iterative in nature. Among the critical decisions in managing such process involves deciding how to partition the system development into iterations. This paper proposes a mathematical model that captures the dynamics of such iterative process. The analysis of two special cases of the model provides an insight into how such decision should be made.Singapore-MIT Alliance (SMA

External financial dependence and firms' crisis performance across Europe

Economic research has often relied on a measure of external financial dependence that is constructed using U.S. data and applied to other countries under the assumption of a stable industry ranking across countries. We exploit unique survey data from seven European countries to show that correlations of financial dependence across countries are weak, questioning this assumption. We then use the novel survey-based measure to show that the global financial crisis had a disproportionately negative impact on the real performance of financially dependent firms

Product Development Process Modeling Using Advanced Simulation

This paper presents a product development process modeling and analysis technique using advanced simulation.The model computes the probability distribution of lead time in a resource-constrained project network where iterations take place among sequential, parallel and overlapped tasks. The model uses the design structure matrix representation to capture the information flows between tasks. In each simulation run, the expected durations of tasks are initially sampled using the Latin Hypercube Sampling method and decrease over time as the model simulates the progress of dynamic stochastic processes. It is assumed that the rework of a task occurs for the following reasons: (1) new information is obtained from overlapped tasks after starting to work with preliminary inputs, (2) inputs change when other tasks are reworked, and (3) outputs fail to meet established criteria. The model can be used for better project planning and control by identifying leverage points for process improvements and evaluating alternative planning and execution strategies. An industrial example is used to illustrate the utility of the model.Center for Innovation in Product Developmen

Patterns of Product Development Interactions

Development of complex products and large systems is a highly interactive social process involving hundreds of people designing thousands of interrelated components and making millions of coupled decisions. Nevertheless, in the research summarized by this paper, we have created methods to study the development process, identify its underlying structures, and critique its operation. In this article, we introduce three views of product development complexity: a process view, a product view, and an organization view. We are able to learn about the complex social phenomenon of product development by studying the patterns of interaction across the decomposed elements within each view. We also compare the alignment of the interaction patterns between the product, process, and organization domains. We then propose metrics of product development complexity by studying and comparing these interaction patterns. Finally, we develop hypotheses regarding the patterns of product development interactions, which will be helpful to guide future research.Singapore-MIT Alliance (SMA

Evolution of Information Control and Centralisation Through Stages of Complex Engineering Design Projects

This paper investigates how to identify potential misalignments between actual and expected information flow patterns among activities at each design stage. We develop a dynamic network model that quantifies how much information control each activity has over time and how the overall control of information is distributed among activities. The model is applied to the design of a biomass power plant. As a result we demonstrate an empirical relationship between information control patterns and design process stages that can be used to guide information flow improvements