Oxygen production using solid-state zirconia electrolyte technology

High purity oxygen is required for a number of scientific, medical, and industrial applications. Traditionally, these needs have been met by cryogenic distillation or pressure swing adsorption systems designed to separate oxygen from air. Oxygen separation from air via solid-state zirconia electrolyte technology offers an alternative to these methods. The technology has several advantages over the traditional methods, including reliability, compactness, quiet operation, high purity output, and low power consumption

Joint UK Land Environment Simulator (JULES) Version 2.2 User Manual

The Joint UK Land Environment Simulator (JULES) is a computer model that simulates many soil and vegetation processes. This document describes how to run version 2.2 of JULES. It primarily describes the format of the input and output files, and does not include detailed descriptions of the science and representation of the processes in the model. The first version of JULES was based on the Met Office Surface Exchange System (MOSES), the land surface model used in the Unified Model (UM) of the UK Met Office. After that initial split, the MOSES and JULES code bases evolved separately, but with JULES2.1 these differences were reconciled, so that all versions since v2.1 have had identical code in both the standalone version (as described here) and in the UM

Transitions of social-ecological subsistence systems in the Arctic

Transitions of social-ecological systems (SES) expose governance systems to new challenges. This is particularly so in the Arctic where resource systems are increasingly subjected to global warming, industrial development and globalization which subsequently alter the local SES dynamics. Based on common-pool resource theory, we developed a dynamic conceptual model explaining how exogenous drivers might alter a traditional subsistence system from a provisioning to an appropriation actions situation. In a provisioning action situation the resource users do not control the resource level but adapt to the fluctuating availability of resources, and the collective challenge revolve around securing the subsistence in the community. An increased harvest pressure enabled by exogenous drivers could transform the SES to an appropriation action situation where the collective challenge has changed to avoid overuse of a common-pool resource. The model was used as a focal lens to investigate the premises for broad-scale transitions of subsistence-oriented SESs in Arctic Alaska, Canada and Greenland. We synthesized data from documents, official statistics and grey and scientific literature to explore the different components of our model. Our synthesis suggests that the traditional Arctic subsistence SESs mostly comply with a provisioning action situation. Despite population growth and available technology; urbanization, increased wage labor and importation of food have reduced the resource demand, and we find no evidence for a broad-scale transition to an appropriation action situation throughout the Western Arctic. However, appropriation challenges have emerged in some cases either as a consequence of commercialization of the resource or by severely reduced resource stocks due to various exogenous drivers. Future transitions of SESs could be triggered by the emergence of commercial local food markets and Arctic warming. In particular, Arctic warming is an intensifying exogenous driver that is threatening many important Arctic wildlife resources inflicting increased appropriation challenges to the governance of local harvest.Ye

Risk Based Urban Watershed Management Under Conflicting Objectives

Ecological impairment and flooding caused by urbanization can be expressed numerically by calculating the risks throughout the watershed (floodplain) and along the main stems of the streams. The risks can be evaluated in terms of the present and/or future. This article describes the methodologies for ascertaining the risks in the Geographical Information Systems (GIS) environment. The objectives of urban flood controls and ecological preservation/restoration of urban waters are often conflicting and, in the past, the sole emphasis on flood control led to destruction of habitat and deterioration of water quality. An optimal solution to these two problems may be achieved by linking the risks to the concepts of risk communication, risk perception, and public willingness to pay for projects leading to ecological restoration and ecologically sustainable flood control. This method is appropriate because, in each case, public funds are used and the projects require approval and backing of policy makers and stakeholders. This article briefly describes a research project that attempts to resolve the conflict between the flood protection and stream ecological preservation and restoration and suggests alternative ways of expressing benefits of urban stream flood control and restoration projects

Local and regional-scale societal dynamics in grizzly bear conservation

Conserving grizzly bear populations is a significant challenge for wildlife managers throughout North America. Much fruitful research has been conducted on the biology of grizzlies, but the human dimensions of bear management remain poorly understood. This imbalance has created conflicts between management agencies and local inhabitants that can jeopardize ecosystem management and planning programs in which grizzlies often feature as key components. Broadly, the goal of this study was to understand how and why such conflicts occur. Qualitative data analysis methods and the policy sciences\u27 interdisciplinary problem analysis framework, along with insights from adaptive governance and co-management concepts, resilience theory, and political ecology, were used to analyze and compare four case studies of grizzly bear management in Canada (the Foothills Model Forest, Alberta; Kluane region, Yukon; the Inuvialuit Settlement Region, Northwest Territories and Yukon; Baker Lake, Nunavut). A coordinated, regional ecosystem-scale approach that aims to preserve habitat in large wilderness areas and limit grizzly bear mortality is the prevailing conservation paradigm for grizzlies and other large mammals. Originating in the Greater Yellowstone Ecosystem, USA, this paradigm is demonstrably vulnerable to failure when applied elsewhere. In the Foothills Model Forest, an ambitious, well-funded, and collaborative regional conservation program was unable to implement any of its research findings and was prematurely terminated. In the southwest Yukon, an interjurisdictional conservation planning process for grizzly bears was effectively cancelled by co-management partners who had no faith in Kluane National Park\u27s extensive ecological research on grizzlies, and felt that an inaccurate and inappropriate problem definition was being forced on them. Small-scale, community-based initiatives are often promoted as an alternative to traditional state wildlife conservation approaches but they face many challenges and this avenue offers no guarantee of immediate success. For remote communities in particular, horizontal and vertical institutional connections are difficult to establish, yet they are important for facilitating learning and the integration of information. Events in Baker Lake, Nunavut, showed that without such connections local peoples\u27 often-substantial traditional ecological knowledge cannot be integrated effectively into decision processes. In the Inuvialuit Settlement Region the quota system for grizzly bear harvests has been able to successfully incorporate both scientific and traditional knowledge in large part because of its cross-scale institutional network. These latter two cases demonstrate a commonly-held vision for adaptive co-management of bear-human systems. As observed in Baker Lake, the evolution of adaptive co-management can apparently be driven by grizzly bear-human conflicts; focusing events which can transform bear-human systems that have low resilience. The leadership provided by individual champions was also an important determinant of case study outcomes. A key element in the three northern case studies is Aboriginal peoples\u27 concept of respect for bears — which is fundamentally different from western views, despite the widespread assumption by non-Aboriginal resource managers that they don\u27t differ. Rooted in a holistic epistemology that emphasizes human kinship with all other living things, practices of respect can be grouped into four categories: terminology, stories, reciprocity, and ritual. In the southwest Yukon, practices in all four categories form a coherent qualitative resource management system that appears to enhance the resilience of the bear-human system as a whole. This system also demonstrates the possibility of a previously-unrecognized human role in maintaining productive riparian ecosystems and salmon runs. Case study findings point toward an alternative paradigm for grizzly bear conservation, that of respectful coexistence . To achieve respectful coexistence, conventional bear management must be re-defined as coping within social-ecological systems – rather than controlling them – with the aim of building resilience in bear-human systems. Local-scale communicative and adaptive governance institutions will be required, and they must make use of multiple information sources. The primary focus of these adaptive institutions should be on localized, place-based relationships between people and bears, but they must also recognize cross-scale connections among bear-human system elements. Finally, there is a need to determine the limits to the application of respectful coexistence: it must be clearly recognized that this approach will not lead to a utopian coexistence between bears and humans, nor is it intended to. I offer recommendations for implementing respectful coexistence practices in the contexts of the four case studies, and I consider their broader implications for national parks, Aboriginal governance institutions, boundary institutions, and the scientific community. These recommendations provide ideas and arguments that can be used to advance governance practices where the status quo is failing to conserve grizzlies in ways consistent with the social and cultural values of people affected by such policies

High Frequency Electro-Optic Modulators for Integrated Optics

This thesis encompasses the theoretical design and experimental evaluation of a novel type of high speed phase modulator using LiNbO3 and GaAs technology suitable for guided wave optics. A brief review of the development of Integrated Optics and in particular of optical modulators is given in Chapter 1, along with an outline of the aims of this project. Chapter 2 provides a comprehensive survey of the methods available for determining the theoretical propagation constant of a guided wave in a variety of dielectric waveguide configurations. A comparison between the various methods is made to provide an indication of the accuracy and complexity of each procedure for a particular waveguide geometry. The effect of metal films in close proximity to optical waveguides on the propagation characteristics is derived through the effective index method. The results obtained are then applied to minimise absorption losses due to the metal overlay in active devices. The main theoretical design of the proposed electrode structure is developed in Chapter 3. The input impedance of the device is matched to the characteristic impedance of the transmission line drive system at the operating frequency using the standard transmission line equations for low-loss lines. The response of the device is modelled by a computer program which calculates the input impedance of two short circuited transmission lines of unequal length connected in parallel. The program allows the asymmetry of the line lengths, the attenuation constant and characteristic impedance to be independently varied so that their influence upon the overall response may easily be determined. An expression is derived for the theoretical depth of modulation and the power/bandwidth ratio for such a device. Finally a description is given of the numerical methods used to obtain the characteristic impedance and attenuation constant of symmetric and asymmetric coplanar microwave waveguide. The chapter concludes with a brief mention of the analysis procedure for Schottky contacts on GaAs. The general photolithographic and fabrication procedures for forming optical waveguides in LiNbO3 and GaAs are introduced in chapter 4. This chapter also gives a detailed account of the modified lift-off technique which is successfully employed to pattern metal films up to 2mum thick - a technique which is required for the standing wave modulator electrode. The use of proton-exchange waveguides as a suitable optical waveguide for high speed active devices is explored in chapter 5. An initial experimental investigation is presented with the theoretical determination of the refractive index profile for waveguides formed in X- and Z-cut LiNbO3 from the observed optical properties. The fabrication parameters required to produce monomode stripe optical waveguides are determined and verified experimentally for a variety of exchange conditions. Other techniques are discussed which offer more control over the refractive index profile and address the problem of index stability. A brief description of the micro-analytical techniques available to monitor the hydrogen concentration is also given. Chapter 6 describes the methods available for characterising the small signal response of the modulator. A comparison is given between the experimental results and the theoretical predictions. Factors affecting the discrepancies in the response are also mentioned. In particular the uncertainties of the high frequency dielectric constants of LiNbO3 are quantified. Chapter 7 concludes the thesis with an outline of the future work required and the conclusions that may be drawn from the work carried out so far on proton exchange and the standing wave modulator