Study of EVA operations associated with satellite services

Extravehicular mobility unit (EMU) factors associated with satellite servicing activities are identified and the EMU improvements necessary to enhance satellite servicing operations are outlined. Areas of EMU capabilities, equipment and structural interfaces, time lines, EMU modifications for satellite servicing, environmental hazards, and crew training are vital to manned Eva/satellite services and as such are detailed. Evaluation of EMU capabilities indicates that the EMU can be used in performing near term, basic satellite servicing tasks; however, satellite servicing is greatly enhanced by incorporating key modifications into the EMU. The servicing missions involved in contamination sensitive payload repair are illustrated. EVA procedures and equipment can be standardized, reducing both crew training time and in orbit operations time. By standardizing and coordinating procedures, mission cumulative time lines fall well within the EMU capability

An integral equation method for a boundary value problem arising in unsteady water wave problems

In this paper we consider the 2D Dirichlet boundary value problem for Laplace’s equation in a non-locally perturbed half-plane, with data in the space of bounded and continuous functions. We show uniqueness of solution, using standard Phragmen-Lindelof arguments. The main result is to propose a boundary integral equation formulation, to prove equivalence with the boundary value problem, and to show that the integral equation is well posed by applying a recent partial generalisation of the Fredholm alternative in Arens et al [J. Int. Equ. Appl. 15 (2003) pp. 1-35]. This then leads to an existence proof for the boundary value problem. Keywords. Boundary integral equation method, Water waves, Laplace’

Growth, decline and locational change in the English silk industry of the nineteenth century: a study in historical geography

The English silk industry, by its extreme fluctuations in profitability and its widespread distribution makes an interesting geographical case study of some of the forces which affected the location of industry during the Industrial Revolution. This thesis sets out to analyse the industry's changing location in times of expansion and contraction, particularly in its mechanised branches, during the nineteenth century. The broad locational pattern of the silk industry was established during the eighteenth century when a considerable increase in the size of the industry was accompanied by spatial expansion: the old concentrations of manufacturing in London declined in importance and new centres, particularly in the Pennine province, but also in parts of southern England assumed greater significance. The first four chapters examine the factors, for example power supplies and competition for labour, which influenced its location. Because of its uncertain profitability, there were few districts in which silk could dominate the local labour force and so secure a measure of protection from stronger industries. Its labour force was thus liable to be eroded during the industry's frequent recessions and was only rebuilt with difficulty in subsequent booms. The supply of labour is therefore seen as a major factor affecting the changing location of silk manufacture, though competition for other resources, such as power and factory space were also significant, particularly in the Pennine province. The broad pattern of the industry's distribution had been established by the mid-nineteenth century and from this time there is a wealth of statistical information available for the size and distribution of the industry in the Factory Inspectors' Returns and the Census. Chapter 5 uses these sources to give a systematic account of the distribution and structure of the industry in about 1850. Despite its widespread distribution it is evident that there existed compact localities in which silk manufacturing was concentrated and that here the domestic, as well as the factory workers were found. Moreover, there were four districts, London, Lancashine the South West Pennines and Coventry which were the dominant centres of the trade and together accounted for most of the industry's employment. From an analysis of the technical data contained in the Factory Inspectors' Returns it is possible to distinguish some regional contrasts in the technical advancement and organisation of the industry. Chapter 6 concludes that in general silk manufacturing in the south was labour intensive and technically backward while in the Pennines contact and competition with the other textile trades made for a more advanced industry. Chapters 7 and 8 analyse the reaction in the various regions to one of the most extreme fluctuations in fortune that the industry experienced, in terms both of changing techniques and organisation and of the size and distribution of the labour force. Differences between the throwing and weaving branches in their response to boom and slump were apparent and the greater strength of the Pennine industry was again demonstrated. Finally Chapter 9 examines the long term decline of the industry after the Free Trade Treaty of 1860. Competition exposed the weaknesses of the industry and at a national level contraction was inevitable. But some of the regional specialisms had the ability to persist despite the general malaise, and it was not until the twentieth century that silk manufacturing was located almost entirely in one region, the South West Pennines

Study of contamination of liquid oxygen by gaseous nitrogen First quarterly report, 1 Jul. - 30 Sep. 1964

Analytical model development for contamination study of liquid oxygen by gaseous nitroge

Client-facing Interprofessional Project Teams: The Role of Engineers' 'Situated Judgment'

This paper addresses the type of engineering practice associated with ‘client-focused interprofessional project teams’ C-fIPPTs which is a typical pattern of work associated with engineering consulting companies. To do so, the article introduces the concepts of ‘situated judgment’ and ‘immaterial activity’ to the Engineering Studies community. It uses these concepts to demonstrate how engineers with different specialisms, working alongside architects, interior designers, etc., resolve competing conceptions of value among members to enable teams to accomplish project-specific issues. The article makes the above argument by drawing on observational data, interviews and field notes to illustrate the immaterial dimension (i.e. converting non-costed ideas into solutions to problems) of such situated judgments. The article concludes by firstly, explaining how the argument it advances about the distinctive features of engineering work contributes to a broadening of research on engineers work practice and, in doing so, the contribution that engineering studies can make to the field of workplace learning. Secondly, the article highlights the implications of its argument for engineering education and workplace learning

'Articulating value' for clients in a global engineering consulting firm: 'immaterial' activity and its implications for post-knowledge economy expertise

Moulier Boutang’s book Cognitive Capitalism introduces a radically different conception of the key resources – ‘immaterial labour’ and ‘capture of externalities’ – for economic activity, compared with the argument in the knowledge economy discourse that professionals manipulate ‘symbols’. The paper explores this claim by firstly, outlining the tenets of Moulier Boutang’s argument and explaining why it introduces a new conception of value compared with how that concept is normally defined in neo-classic and Marxist economics. Secondly, explaining why client-facing project teams constitute a paradigmatic example of immaterial activity. Thirdly, makes visible the modes of activity which facilitate the capture of externalities by supplementing Moulier Boutang’s concept with Boltanski and Thevénot’s ideas about different economies or conceptions of worth. Case study evidence of a global engineering consulting company is then used to identify three expressions of immaterial activity – educative’, ‘experimental’ and ‘entrepreneurial’ – that assist engineers to articulate their value to clients. The paper concludes by arguing immaterial activity: (i) constitutes a form of expertise that is very different from the prevailing knowledge economy wisdom that knowledge workers manipulate symbols explicitly or tacitly; and, (ii) problematises the sui generis nature of the global ‘employability’ skills discourse

Encoding One Logical Qubit Into Six Physical Qubits

We discuss two methods to encode one qubit into six physical qubits. Each of our two examples corrects an arbitrary single-qubit error. Our first example is a degenerate six-qubit quantum error-correcting code. We explicitly provide the stabilizer generators, encoding circuit, codewords, logical Pauli operators, and logical CNOT operator for this code. We also show how to convert this code into a non-trivial subsystem code that saturates the subsystem Singleton bound. We then prove that a six-qubit code without entanglement assistance cannot simultaneously possess a Calderbank-Shor-Steane (CSS) stabilizer and correct an arbitrary single-qubit error. A corollary of this result is that the Steane seven-qubit code is the smallest single-error correcting CSS code. Our second example is the construction of a non-degenerate six-qubit CSS entanglement-assisted code. This code uses one bit of entanglement (an ebit) shared between the sender and the receiver and corrects an arbitrary single-qubit error. The code we obtain is globally equivalent to the Steane seven-qubit code and thus corrects an arbitrary error on the receiver's half of the ebit as well. We prove that this code is the smallest code with a CSS structure that uses only one ebit and corrects an arbitrary single-qubit error on the sender's side. We discuss the advantages and disadvantages for each of the two codes.Comment: 13 pages, 3 figures, 4 table

Protecting Quantum Information with Entanglement and Noisy Optical Modes

We incorporate active and passive quantum error-correcting techniques to protect a set of optical information modes of a continuous-variable quantum information system. Our method uses ancilla modes, entangled modes, and gauge modes (modes in a mixed state) to help correct errors on a set of information modes. A linear-optical encoding circuit consisting of offline squeezers, passive optical devices, feedforward control, conditional modulation, and homodyne measurements performs the encoding. The result is that we extend the entanglement-assisted operator stabilizer formalism for discrete variables to continuous-variable quantum information processing.Comment: 7 pages, 1 figur