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River systems play an important role in the filling of sedimentary basins and record the history of external forcing processes, such as climate, tectonics and sea-level change, acting on them. They are potential reservoirs for oil, gas and water, and can host coal and placer mineral deposits. Because of the complex interplay between the external forcing processes, however, understanding of the genesis of the stratigraphy of river systems and interpreting the stratigraphy correctly is far from straightforward. Current conceptual models are oversimplified, and more insight into the impact of external forcing processes must be gained to improve these models. The aim of this study was to assess the impact of climate (i.e., discharge and sediment influx) on the development of the large-scale stratigraphic architecture of river systems, in isolation and in conjunction with sea-level fluctuations, through an analogue modelling approach. Analogue physical models reproduce the long-term average effects and products of the transport processes in a river system, rather than the transport processes themselves. An advantage of analogue modelling over numerical modelling is that it is hard to make the model fit preconceived notions about the results, making it possible to test and develop conceptual models. The impact of climate (i.e., discharge and sediment influx) on the large-scale stratigraphic architecture of river-delta-shelf-basin systems appears not to be as dominant as the impact of sea-level change, but it does significantly affect the smaller scale stratigraphic architecture, such as the relative size of systems tracts and the rate and extent of erosion. Furthermore, we found a fundamental difference between the impact of changes in discharge and the impact of changes in sediment influx on the yield and mass accumulation at the mouth of a river system. River systems can act as buffers for rapid changes in sediment influx, while they react very rapidly to changes in discharge. Thus, the small-scale stratigraphy at the river mouth is controlled mainly by changes in discharge, and the large-scale stratigraphy is controlled by changes in sediment influx (and sea-level fluctuations). Also, because the response of the river gradient to an increase in discharge is the opposite to its response to an increase in sediment influx (and vice versa), the mass accumulation at the river mouth, combined with the overall stratigraphic architecture of the system, can be used to constrain paleo-discharge and paleo-sediment influx scenarios. Finally, our experiments show that a complex stratigraphic architecture is not necessarily the result of complex forcing, but can result from very simple changes in discharge. To assess the development of the stratigraphy in physical models, a new method for processing the data obtained in the experiments was developed. Series of subsequent digital elevation models of the surface of the model are converted, using custom-made software, into synthetic three-dimensional stratigraphy, containing true isochronous surfaces. This data set contains the development of the system through time in three dimensions, and can be presented in various formats, such as geological maps, geological sections and Wheeler diagrams.

Cooling is a critical part of data center’s infrastructure, and with ongoing demands in data processing and storage, thermal management issues are of great concern. Some imperative methods of removing heat are either using air or liquid (preferably water or refrigerant). When high power density modules are involved, liquid cooling addresses some of the problems faced by air cooling as liquid coolants have higher thermal capacitance. Also, in the case of multi-chip modules, a non-uniform heating due to multi-core generates hot-spots and increases temperature gradients across the module. A dynamic cold plate along with a self-regulated flow control device was developed to address these issues. A temperature sensing self-regulated flow control device (FCD) is placed at the exit of each section to regulate the required flow. But to implement this at rack level, a good control strategy is required. This study presents a CFD analysis of such control strategy to save Pumping power on a direct liquid cooled rack using a concept of dynamic cooling along with a self-regulated flow control device. It’s important to save pumping power as it is one of the most energy consumed areas in the data center. The main objective of this study is to assess the flow rate and pressure distribution on the rack in order to control excessive pumping power usage and enhance cooling system efficiency.

The merging of empirical tests and theoretical models allows us to make sense of complex biological concepts. This thesis explores questions of biological variation (both within and between species) and its persistence through evolutionary time scales primarily through the development of mechanistic models. The first chapter uses a game theory framework to describe drivers of persistence in systems of alternative strategies, and presents a new framework to describe competition within large systems. The second chapter describes the plastic system of developmental polyphenisms in the Mexican spadefoot toads, Scaphiopus multiplicata using a game theory framework. The possibility that anthropogenic climate change will alter selection on developmental polyphenisms is explored. The third chapter uses a mechanistic ecophysiology-based model to explore extinction risk in seven species of tropical New World day geckos (Sphaerodactylidae, Squamata). These studies highlight the importance of incorporating empirical data in modeling. Given anthropogenic changes to climate and habitat availability, ecosystem resilience of particular concern to conservationists. We need tools to predict how species losses will affect eventual equilibrium outcomes – whether ecosystems will survive in a recognizable state, or whether the loss of key species can affect larger-scale stability.

This dissertation is about the development of corporate responsibility and sustainability advocacy in Ireland. It shows how the biopolitics of corporate responsibility (or CR) and sustainability was rendered—by CR advocates and interested companies—as an ethical ecology, not dissociated from the biopolitical but rooted in it. By ‘ecology’ I mean to refer to the growing consciousness and deliberate cultivation of the interconnections, dependencies and feedback as well as responsibilities between heretofore discreet parts of the social landscape—between business and employees for example. These nascent interconnections—between what we might think of as systems and their environment—were also being presented as compelling ethical striving and to an extent, facilitating it. Importantly this effort was to be directed towards what was coming to be understood by the terms ‘sustainability’ and ‘responsible business.’ Hence, I also used the word ‘ecology’ in the sense of how this argument for ethics had roots in concern for the planet itself and for the very survival of the human race. In a deeper sense then, the matrix or the features of biopower—“[1] one or more truth discourses about the ‘vital’ character of living human beings; [2] an array of authorities considered competent to speak that truth; [3] strategies for intervention upon collective existence in the name of life and health; [4] and modes of subjectification, in which individuals work on themselves in the name of individual or collective life or health” (Rabinow and Rose 2006, 195)—permeated this concern with sustainability (the ecology or the engagement of systems and environments in the name of ‘life’ as such) and certainly as it was rendered in this arena of business and all that surrounds it, sustainability weighed heavily on ethical quest or government of the self for its potential for success. Furthermore, these logics could be extended into the less biological concern with the sustainability of our ways of life—including communities, businesses and ...

In the analysis of unprotected loss-of-flow and overpower transients of liquid metal fast breeder reactors, the modeling of heat transfer from molten fuel, ejected into the coolant channel after cladding rupture, to liquid sodium is an important part of fuel-coolant interaction (FCI). Some of the ejected molten fuel fragments into small particles and gets dispersed in the coolant. In the PLUT02 code model and other modeling efforts of FCI it is assumed that the fuel particle to liquid sodium heat transfer is limited only by the thermal conduction resistance of the fuel because the thermal conductivity of liquid sodium is about 30 times higher than that of mixed oxide. The fuel particle (assumed to be a sphere) surface temperature, under this assumption, equals the coolant temperature. The purpose of the present analysis is to obtain the value of meter C/sub 1/ (for V/sub l/ = 1) by solving the linear transient heat conduction equation a constant parameter in the equation for evaluating the fuel-coolant heat transfer coefficient.

Chiefly tables. ; Second in a series. ; Mode of access: Internet.

Energy efficiency is among the cheapest, cleanest, and most widely available of energy resources. Improved energy efficiency provides opportunities to sustainably expand energy services and support development and economic growth, contributing to higher living standards, as well as reducing greenhouse gas emissions. In developing countries, where demand for energy is growing rapidly, the potential for energy efficiency improvements is significant, particularly in the residential sector. The purpose of this guide is to raise awareness of behavioral approaches to achieving development outcomes, demonstrate the role that behavioral sciences can play in promoting energy efficiency, and provide guidance on how to integrate behavior change approaches into projects.

Establishing a sustainable future requires the replacement of petroleum as the primary carbon source for modern industry. Biomass derived species offer a promising alternative to petroleum derived species for fuel and chemical production. However, such species are often low molecular weight and heavily oxygenated, and require reductive upgrading or coupling to form more valuable species. Electrochemistry offers a promising technology for biomass upgrading. Easily utilizing renewable energy sources, such as wind and solar power, electrochemical reduction uses an applied electrical potential to drive the reduction of biomass species. This technique applies to a wide range of functional groups, including aromatic rings, C=C bonds and carbonyls. Despite these advantages, electrochemical biomass upgrading largely remains unviable due to poor catalysts and a lack of mechanistic understanding. This work seeks to advance the mechanistic understanding of electrochemical biomass upgrading by investigating the electrochemical reduction of carbonyl species. ☐ The first chapter investigates benzaldehyde reduction on four different metals: Cu, Au, Pt and Pd. Reactivity tests show a large difference in reduction selectivity between metals, with Cu showing benzaldehyde coupling ability, while the other metals do not. In situ infrared spectroscopy experiments suggest this difference in coupling ability results from the relative ability of the metal surface to stabilize the ketyl radical reaction intermediate. Spectroscopic features related to the ketyl radical appear on Au and Cu surfaces, but not on Pt or Pd. The appearance of radicals on both Au and Cu suggests the difference in Cu and Au coupling ability results from a lower radical concentration on Au, likely due to lower radical stability. On Pt and Pd, CO appears under reduction conditions, suggesting the general instability of benzaldehyde adsorbates limits surface coverage and coupling ability. Combined, the spectroscopic and reactivity evidence suggest ketyl radical stability acts as a key descriptor of benzaldehyde coupling ability. ☐ Subsequently, the second chapter extends the analysis to the reductive coupling of benzaldehyde and furfural on Cu and Pb electrodes. Under simultaneous reduction, reactivity tests show both the self-coupling and cross-coupling of the aldehyde species on the two metal surfaces, but with different selectivities. Cu shows greater selectivity for cross-coupling, whereas Pb favors furfural coupling. Comparison with a stochastic model suggests both metals deviate from stochastic coupling control, with greater deviation on Pb, likely due to a larger difference in aldehyde binding energies. Cyclic voltammetry and in situ spectroscopy further support stronger benzaldehyde adsorption compared to furfural on both metals, with a larger difference in binding energy for Pb. Combined, the reactivity, cyclic voltammetry and spectroscopy experiments suggest that the cross-coupling of two aldehydes follows a two reactant Sabatier rule, with optimum cross-coupling for electrodes with similar reactant binding energies. ☐ Finally, the third chapter investigates the effect of structure on reduction activity for aliphatic ketone reduction on Pb and Au electrodes. Specifically, reduction kinetics are investigated for acetone, 2-butanone, 2-pentanone, 2-hexanone, cyclopentanone and cyclohexanone. Reactivity tests show only an alcohol product, with reduction activity decreasing with size for the linear ketones. Cyclic species show higher activity than the corresponding linear species, with activity increasing with ketone size. Similar Tafel slopes suggest a common reduction mechanism for all ketones on both metals. A change in Tafel slope with potential suggests a change in the ketone reaction network. Comparison with a simple model suggests this change likely results from increased hydrogen competition at lower potentials. Rate order and pH dependent measurements further support this explanation. Temperature dependent measurements suggest that rate decreases with ketone size result from a smaller pre-exponential factor. Comparison with a kinetic model suggests the decrease in pre-exponential factor results from weaker orbital overlap for larger ketones, with hydraulic radius offering a good descriptor for ketone size. Cyclohexanone proves the exception, likely due to a different binding orientation or higher binding strength. Activation energy measurements suggest similar intrinsic activation energies for all ketone species, with variation in observed activation energy resulting from different adsorption energies.

Issued September 26, 1919. ; Mode of access: Internet.

"July 31, 1968." ; Includes bibliographical references (p. 45-46) ; Sponsored by the Air Force Office of Scientific Research, Office of Aerospace Research, United States Airforce, under AFOSR Contracts ; Mode of access: Internet.