Call number: LD2668 .T4 1965 D54 / Master of Science

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Since becoming an ANSI standard in 1994, Fibre Channel has matured into a high-speed reliable data communication solution. Fibre Channel uses point-to-point, arbitrated loop, or switched topologies, to provide a wide range of options for data storage and highspeed data transfer applications. Unlike Gigabit Ethernet, Fibre Channel supports protocols such as HIPPI-FP, SCSI and IPI, allowing for greater flexibility when designing systems. However, the wide range of options supported in the Fibre Channel standard can be the source of misunderstanding and incompatibility. This paper intends to clear up some of the misconceptions about Fibre Channel by presenting the current standard and discussing how Fibre Channel can be used in data acquisition systems. Since these systems often require extremely high throughput for routing data, as well as high speed data storage to long term media, solutions are not often cut and dry. This paper will give examples of how using different layers of the Fibre Channel protocol will meet the needs of today’s data acquisition requirements. It provides a brief overview of Fibre Channel technology and identifies the different types of Fibre Channel products available. It provides examples of how commercial-off-the-shelf (COTS) products can be used to build data acquisition and storage systems requiring throughputs of up to 90 Mbytes per second on a single fiber. Additionally, it shows how multiple fibers can be used to achieve much higher data rates.

This thesis progresses from a ‘science and technology studies’ (STS) perspective to consider the ways that expert stakeholders perceive and communicate uncertainties and risks attached to carbon dioxide (CO2) capture and storage (CCS) research and development, and how this compares with policy framings and regulatory requirements. The work largely falls within the constructivist tradition in sociology, but also draws on literature from the philosophy of science and policy-­‐oriented literature on risk and uncertainty. CCS describes a greenhouse gas (GHG) mitigation technology system that involves the capture, pressurisation, transportation, geological injection and long-­‐term storage of CO2 as an alternative to atmospheric emissions. Only few and relatively small applications exist at the moment and research efforts are on going in many countries. The case for developing CCS towards large-­‐scale, commercial deployment has largely been presented as follows since the mid-­‐ 1990s: climate change mitigation is the developed world’s historical responsibility and must be addressed urgently; chief amongst GHGs is CO2, which makes up more than three quarters of emissions; the vast majority of CO2 is emitted from the combustion and gasification of hydrocarbons – oil, gas and coal – for energy generation; transitioning away from these high-­‐CO2 primary energy sources will likely take several decades at the least; therefore, CO2 capture systems should be designed for power and industrial emissions in developed countries, as well as emerging economies where energy suppliers will continue to construct relatively cheap and well understood high-­‐CO2 generation plants. The development of large-­‐scale CO2 capture has thus arisen from a concern with engineering a technological system to address a CO2 legacy in the developed world, and a high-­‐CO2 trajectory in developing/emerging countries, rather than on the back of purely scientific curiosity. And the potential for large-­‐scale development has been presented on the back of a variety of scientific and technical evidence, as well as the urgency of the policy objective and related aims. Research activities, often concentrated around technology demonstration projects, are the primary focus of the first part of this thesis. In the second part I consider the extent to which research has shaped policy developments, and how regulations have subsequently informed a more detailed research agenda. I follow a ‘grounded theory’ methodology as developed by Glaser and Strauss (1967) and take additional guidance from Glaser’s (1992) response to Strauss’ later writings as well as Charmaz (2006) and Rennie (2000), and use a mix of qualitative and quantitative analytical methods to assess my data. These include information from 60 semi-­‐structured interviews with geoscientists and policy stakeholders; close readings of scientific publications, newspaper articles, policies and regulatory documents; statistical evidence from a small survey; quantitative analysis of newspaper articles; and social network analysis (SNA) of scientific co-­‐authorship networks. Theory is drawn from STS literature that has been appropriate to address case study materials across each of the 7 substantive chapters. The first section of the thesis considers expert claims, with a focus on geoscience research, and draws on literature from the closely related ‘social shaping of technology’ (SCOT) and ‘sociology of scientific knowledge’ (SSK) programmes, as well as Nancy Cartwright’s philosophy of science. The second half of the thesis draws on the ‘co-­‐production’ framework and Wynne’s (1992) terminology of risk and uncertainty, to assess relations between risk assessment and risk management practices for CCS. I likewise draw on literature from the ‘incrementalist’ tradition in STS to ask whether and how understandings of technology risk, governance and deployment could be improved. Each chapter presents new empirical material analysed with distinct reference to theories covered in the introduction. Chapter 2 provides a general overview of the history, technology, economics and key regulatory issues associated with CCS, which will be useful to assess the theoretically driven arguments in subsequent chapters. Chapter 3 draws on the concept of ‘interpretive flexibility’ (Pinch and Bijker 1984) to assess a range of expert perceptions about uncertainties in science, technology and policy, and I develop a substantive explanation, ‘conditional inevitability’, to account for an epistemic tension between expressions of certitude and the simultaneous acknowledgement of several uncertainties. Chapter 4 continues the enquiry into stakeholder perceptions and draws on Haas’ notion of ‘epistemic communities’ (Haas 1992) to assess geoscientists’ work practices. I complement this framing with a close look at how uncertainty is treated in simulation modelling and how conclusions about storage safety are formulated, by drawing on Nancy Cartwright’s philosophy of science (Cartwright 1999) and Paul Edwards’ account of complex system modelling for climate change (Edwards 2010). The chapter shows how shared understandings of adequate evidence and common analytical tools have been leveraged to present relatively bounded and simple conclusions about storage safety, while geoscientists nevertheless recognise a high degree of uncertainty and contingency in analyses and results. Chapter 5 continues the focus on knowledge production in the geosciences and is supported by SNA data of workflow patterns in the Sleipner demonstration project. The analysis shows how a few actors have had a pivotal role in developing insights related to storage safety particularly on the back of seismic monitoring and other data acquired through industry partnerships. I therefore continue the chapter with a deconstruction of how seismic data has been used to make a case for the safety of CO2 storage, again drawing on Cartwright and others (Glymour 1983) to explain how individual findings are ‘bootstrapped’ when conclusions are formulated. I show how a general case about storage safety has emerged on the back of seismic data from Sleipner as well as a shared understanding among geoscientists of how to account for uncertainties and arrive at probable explanations. Chapter 6 considers to what extent scientific research has given shape to, and in turn been shaped by, CCS policy and regulations in the EU, drawing on Wynne’s (1992) terminology of risk and uncertainty as well as legal scholarship (Heyvaert 2011). I conclude that a ‘rational-­‐instrumental’ interpretation of uncertainty and precaution has furnished a compartmentalised understanding of risk assessment and risk management practices. Chapter 7 continues to look at the ways that risk assessment methodologies influence risk management practices through a case study of the Mongstad CCS demonstration project in Norway. I draw on ‘incrementalist’ literature (Lindblom 1979; Woodhouse and Collingridge 1993) to consider alternative conceptualisations of technology development and risk management when expectations clash with scientific uncertainties and criticism. Chapter 8 draws on insights from across STS (Downs 1972; Collingridge and Reeve 1986; Wynne 1992) to create a novel conceptual model that accounts for recent years’ developments in CCS governance. Here I conclude that setbacks and criticisms should be expected when analyses have largely presented CCS as a technical problem rather than a socially contingent system. Following Stirling (2010) I conclude that scientists and policymakers should instead strive to present complexity in their analyses and to engage with wider publics (Yearley 2006) when technical analysis is inseparable from socially mediated indeterminacies (Wynne 1992), to increase the chance of more successful engagement practices (Wynne 2006). The conclusions at the end of the thesis seek to draw out interpretive and instrumental lessons learned throughout.

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / This paper presents efforts in developing a data management system and storage infrastructure for assisting test engineers in achieving information superiority and maintaining vital up-to-date information. The focus of this Paper is to generate support for a technology refresh, upgrading the major data centers that share in the responsibility of processing telemetry information. We illustrate how our efforts fit into this goal and provide an overview of our concept for a revolutionary transformation in data management systems. We present the significance of this new technology and suggest a path to implementing the solution.

Thesis (D.Sc.)--Stellenbosch University, 1953. / ENGLISH ABSTRACT: no abstract available / AFRIKAANSE OPSOMMING: geen opsomming

published_or_final_version / Urban Planning / Master / Master of Science in Urban Planning

published_or_final_version / Industrial Engineering / Master / Master of Science in Engineering

published_or_final_version / Business Administration / Master / Master of Business Administration

The design of nanoparticles in mesoporous supports is explored through synthetic strategies of electrophoretic deposition and electroless deposition with application towards energy storage. Electrophoretic deposition of nanoparticles into a mesoporous thin film is examined using charged nanocrystals in a low-permittivity solvent. To provide a basis for the deposition, the mechanism of particle charging in a low-permittivity solvent was studied. Dispersions of carbon black particles in toluene with an anionic surfactant were characterized using differential-phase optical coherence tomography with close electrode spacing to measure the electrophoretic mobility. The particle charge in concentrated dispersions was found to decrease as a function of increasing surfactant concentration. Partitioning of cations between the surfactant-laden particle surface and micelle cores in the double-layer was found to govern the dynamics of particle charging. Subsequently, charged Au nanocrystals were deposited by electrophoresis within perpendicular mesochannels of a TiO2 support. High loadings of 21 wt% Au with good dispersion were achieved within the mesoporous TiO2 support using electrophoretic deposition, which would otherwise be inhibited by the weak nanocrystal-support interaction. According to a modified Fokker-Planck equation, the mean penetration depth of a single nanocrystal inside of the perpendicular pores was found to be dependent on the electric field strength, electrophoretic mobility, pore diameter, nanocrystal size, and local deposition rate constant. Nanocomposites for electrochemical capacitors were designed via electroless deposition of redox-active MnO2 in a high surface area mesoporous carbon support. Disordered mesoporous carbon supports with a pore size of ~8 nm were used both in amorphous (AMC) and graphitic (GMC) form, with a ~1000-fold larger conductivity for GMC. High loadings of 30 wt% MnO2 were achieved in the AMC in the form of ~1 nm thick domains, which were highly dispersed throughout the support. Oxidation of the GMC was necessary to facilitate wetting and deposition of the MnO2 precursor in order to achieve high loadings of 35 wt% MnO2 with ~1 nm thickness. High gravimetric MnO2 pseudocapacitances of >500 F/gMnO2 were achieved at low loadings and low scan rate of 2 mV/s for both carbon supports. However, at high scan rates ≥100 mV/s, the MnO2 pseudocapacitance is twofold larger for MnO2/GMC, relative to MnO2/AMC. Sodium ion diffusion throughout both MnO2/AMC and MnO2/GMC was shown to be facile. For the GMC versus AMC support, the higher MnO2 pseudocapacitance is attributed to the higher electronic conductivity, which facilitates electron transport to the MnO2 domains. / text

This dissertation explores the social and political strategies performed by an intermediate elite household, Sak Ch'en, in an effort to maintain their social status and power in the evolving landscape of La Milpa during the Late to Terminal Classic Transition (A.D. 800-850/900). Explicitly, this research investigates how Sak Ch'en preserved the continuity of social order by exercising their funds of power and by feasting, gifting, and storing socially charged goods. Excavations were conducted at one residential complex during the 2009-2012 field seasons at the site of La Milpa, Belize, to delineate the political, social, and economic dimensions of intermediate elite household life during large-scale structural changes of the polity. Analyses of recovered ceramic assemblages and additional artifacts demonstrate the presence of feasting, the storage of socially valuable goods, and the production of cloth items during the Late to Terminal Classic period. Feasting in Maya society was enacted as a social, political, and economic strategy, which enabled the ruling elite to attract political support and create exclusive alliances. It is my deduction that at Sak Ch'en, feasting operated as a forum to display household rank, validate status, and maintain power through food acquisition, production, consumption, and distribution. By hosting a feast, Sak Ch'en inhabitants solidified existing political and socioeconomic relationships and encouraged the development of new household associations. Analyses of spindle whorls at Sak Ch'en revealed the production of cloth goods for local consumption and possibly gift exchange. Gift-giving may have been employed at Sak Ch'en as a strategy that binded individuals or groups into reciprocal debt relationships. Further, the gifting of food during this unstable period publicly displayed access to, or possession of, surplus at Sak Ch'en, which strongly reiterated asymmetrical economic power relations between households. Lastly, the storage of goods reassured the replication of activities and rituals tied to ideological concepts of social order. These strategies were implemented at Sak Ch'en as reiterative mechanisms operating to guarantee the reproduction of household power and status. / text