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Latent thermal energy storages (LTESs) in combination with heat pumps and smart control strategies can maximize the utilization of renewable energy sources for heating and cooling. However, smart energy management with model predictive control (MPC) requires monitoring the total energy stored in the LTES, which is determined by the liquid fraction of the phase change material (PCM). Measuring the liquid fraction is challenging and the diverse liquid-fraction sensing approaches pose a trade-off between accuracy and ease of implementation. The present study aims to quantify the effect of the liquid fraction sensing accuracy on the performance of MPC strategies for heating systems with LTES. For this purpose, a residential heating application with an energy management system is analyzed. The heating system consists of a heat pump, an LTES and a photovoltaic array. The heat pump can be driven by the photovoltaic array and the electric grid. The energy management system uses MPC based on Mixed-Integer Linear Programming. Representative seasonal profiles for the heating load and weather conditions are used as forecasts for the MPC. The performance of the energy management system is assessed in terms of total heating cost for different error values in the estimation of the liquid fraction of the PCM in the LTES. The heating cost is found to proportionally increase with the absolute error in liquid fraction due to reduced utilization of the LTES capacity.

Statistical QCD predicts that with increasing density, strongly interacting matter will undergo a transition to a plasma of deconfined quarks and gluons. High energy heavy ion collisions are expected to permit experimental studies of this transition and of the predicted new state of matter. 22 refs., 6 figs.

Anthropogenic climate change is predicted to be a major cause of extinctions. Therefore, a major aim of climate change ecology is to understand how species are being impacted and identify which species are most at risk. However, the ability to make these broad generalisations requires large-scale comparative analyses based on appropriate assumptions. This thesis investigates how European birds respond to changes in climate, the validity of several common assumptions, and identifies which species or populations are most at risk based on multiple long-term datasets. Our understanding of how different responses relate and how they affect population persistence is lacking. A conceptual hierarchical framework is introduced in chapter one to better understand and predict when climate-induced trait changes (phenology or physiology) impact demographic rates (survival or reproduction), and subsequently population dynamics. I synthesise the literature to find hypotheses about life-history and ecological characteristics that could predict when population dynamics will likely be affected. An example shows that, although earlier laying with warmer temperatures was associated with improved reproduction, this had no apparent effect on population trends in 35 British birds. Number of broods partly explains which species are most at risk of temperature-induced population declines. It is often assumed that populations within species respond similarly to climate change, and therefore a single value will reflect species-specific responses. Chapter two explores inter- and intra-specific variation in body condition responses to six climatic variables in 46 species over 21 years and 80 sites. Body condition is sensitive to all six variables (primarily in a non-linear way), and declines with warmer temperatures. I find that species signals might not exist as populations of the same species are no more alike than populations of different species. Decreased body condition is typically assumed to have detrimental consequences on species’ vital rates and population dynamics, but this assumption has rarely been tested. Expanding on chapter two, chapter three shows that temperature-induced declines in body condition have no apparent consequences on demography and population dynamics. Instead, temperature has strong effects on reproductive success and population growth rates via unknown traits and demographic rates. Much of the literature investigating climatic impacts assumes that temporal trends accurately reflect responses to climate change, and therefore investigate trait changes over time. In chapter four, I use two long-term datasets to demonstrate that, for four different types of trait responses, trait variation through time cannot be assumed to be due to warming. Non-temperature causal agents are important…

Creative arts have long been used for making meaning and conveying knowledge. Music, dance, painting, and storytelling are art forms that have the power to connect us to each other. This research investigates using the arts to connect us to the planet as well. I refer to this relationship as Econnection. Originally published as “Creative Arts-based Pedagogies in Early Childhood Education for Sustainability (EfS): Challenges and Possibilities” (Ward, 2013) the central research question was: In what ways can self-generated creative arts experiences assist early childhood educators to support young children to learn about the environment?

Urban pollution is a current problem, constituting a serious health risk. Many pollutants are present in the urban atmosphere, they are mainly anthropogenic, resulting from the combustion of coal. Several studies have shown the harmful effects of these pollutants, particularly on the respiratory system. Through a library review, we want to explore the effects on the health of general population and of outdoor workers exposed to the products resulting from the combustion of coal, in order to compare them with the estimated effects of the pollutants from the new generation coal plants, certainly less harmful to the environment. In recent years investments in "clean technologies" have resulted in a rapid and significant reduction of all polluting emissions: sulfur dioxide, dust, oxides of nitrogen, ash and gypsum resulting from the desulfurization process. To conclude in the light of the scientific literature we can say that the activation of coal plants based on technologies for the maximum containment and optimal treatment of the production cycle is essential to defend both the environment and the health of the population. Nevertheless it remains necessary to ensure a systematic monitoring of the environment of sanitation and food processing of the population living in the area, with a long-term follow-up.

Significant research efforts are underway to develop commercially viable, technically feasible, highly efficient, and highly reliable power converters for renewable energy, electric transportation, and various industrial applications. This chapter presents state-of-the-art knowledge and cutting-edge techniques in various stages of research related to impedance source converters/inverters, including the concepts, advantages compared to existing technology, classification, current status, and future trends. Electric power generation comprises traditional power generation, such as hydroelectric, thermal and nuclear power production, and renewable energy sources, which already has a large penetration joined by photovoltaic (PV) and wind energy. In applications that need to boost the voltage, the Z-source converter is a possibility. Power electronics is the enabling technology for the energy processing necessary for electronic and electrical equipment of all types, from renewable energy to power systems, from house appliances to aerospace systems. New power electronic devices, such as the SiC and GaN, will definitely improve the Z-source converters' performance.

To more accurately treat severe accidents in fast reactors, a program has been set up to investigate new computational models and approaches. The product of this effort is a computer code, the Advanced Fluid Dynamics Model (AFDM). This paper describes some of the basic features of the numerical algorithm used in AFDM. Aspects receiving particular emphasis are the fractional-step method of time integration, the semi-implicit pressure iteration, the virtual mass inertial terms, the use of three velocity fields, higher order differencing, convection of interfacial area with source and sink terms, multicomponent diffusion processes in heat and mass transfer, the SESAME equation of state, and vectorized programming. A calculated comparison with an isothermal tetralin/ammonia experiment is performed. We conclude that significant improvements are possible in reliably calculating the progression of severe accidents with further development.

We develop a numerical model for coupling of neutron diffusion adn termomechanics in order to stimulate transient behavior of a fast burst reactor. The problem involves solving a set of non-linear different equations which approximate neutron diffusion, temperature change, and material behavior. With this equation set we will model the transition from a supercritical to subcritical state and possible mechanical vibration.

Moral panic, our predisposition to exaggerate threats against our livelihood and start blaming ourselves, is as old as human history. We always feared “others”, people with skin colors or ethnicity other than ours, people coming from other corners of the globe, and the infectious diseases the strangers might bring along. This paper deals with a new version of such moral panics which is arguably even more intense than the previous ones, but which relates to a new dimension of human experience, namely globalization. The health, economic and environmental challenges we are now faced with are posed globally. The moral panic today stems from this triple challenge. Our central thesis is that these three emergencies are interrelated, but there is no simple causal relationship between them. They can only be addressed in a global manner, while we still live in a world which is segmented into sovereign nation-states.

This paper describes the modeling used in the Advanced Fluid Dynamics Model (AFDM), a computer code to investigate new approaches to simulating severe accidents in fast reactors. The AFDM code has 12 topologies describing what material contacts are possible depending on the presence or absence of a given material in a computational cell, the dominant liquid, and the continuous phase. Single-phase, bubbly, churn-turbulent, cellular, and dispersed flow are permitted for the pool situations modeled. Interfacial areas between the continuous and discontinuous phases are convected to allow some tracking of phenomenological histories. Interfacial areas also are modified by models of nucleation, dynamic forces, turbulence, flashing, coalescence, and mass transfer. Heat transfer generally is treated using engineering correlations. Liquid/vapor phase transitions are handled with a nonequililbrium heat-transfer-limited model, whereas melting and freezing processes are based on equilibrium considerations. The Los Alamos SESAME equation of state (EOS) has been inplemented using densities and temperatures as the independent variables. A summary description of the AFDM numerical algorithm is provided. The AFDM code currently is being debugged and checked out. Two sample three-field calculations also are presented. The first is a three-phase bubble column mixing experiment performed at Argonne National Laboratory; the second is a liquid-liquid mixing experiment performed at Kernforschungszentrum, Karlsruhe, that resulted in rapid vapor production. We conclude that only qualitative comparisons currently are possible for complex multiphase situations. Many further model developments can be pursued, but there are limits because of the lack of a comprehensive theory, the lack of detailed multicomponent experimental data, and the difficulties in keeping the resulting model complexities tractable.