Plate waves for the NDT of diffusion bonded titanium.

Imperial Users onl

Outcasts of the Universe: Shyness in Hawthorne and James

In Outcasts of the Universe, I argue that shyness is a modern dilemma, problematized by the broader shifts in American society: the expanding marketplace, the idealization of the self-made man, the rise of feminism and ever-changing gender roles, and a slow consolidation of the bachelor, the artist, and the aesthete into the stigmatized figure of the homosexual. By drawing on both the lives and works of Hawthorne and James, I theorize shyness as an alternative model of social and sexual engagement in the nineteenth century. In particular, I adapt the queer theory concept of closetedness, a concept that has no equivalent in heterosexual terms--unless it is shyness itself. In doing so, I contribute new insights to the fields of gender studies and to queer theory, both by expanding theories of the closet to heterosexual narratives and by exploring how closetedness might be psychologically overdetermined by shyness, melancholy, and introversion

Modeling and simulation enabled UAV electrical power system design

With the diversity of mission capability and the associated requirement for more advanced technologies, designing modern unmanned aerial vehicle (UAV) systems is an especially challenging task. In particular, the increasing reliance on the electrical power system for delivering key aircraft functions, both electrical and mechanical, requires that a systems-approach be employed in their development. A key factor in this process is the use of modeling and simulation to inform upon critical design choices made. However, effective systems-level simulation of complex UAV power systems presents many challenges, which must be addressed to maximize the value of such methods. This paper presents the initial stages of a power system design process for a medium altitude long endurance (MALE) UAV focusing particularly on the development of three full candidate architecture models and associated technologies. The unique challenges faced in developing such a suite of models and their ultimate role in the design process is explored, with case studies presented to reinforce key points. The role of the developed models in supporting the design process is then discussed

Preliminary Sunyaev Zel'dovich Observations of Galaxy Clusters with OCRA-p

We present 30 GHz Sunyaev Zel'dovich (SZ) observations of a sample of four galaxy clusters with a prototype of the One Centimetre Receiver Array (OCRA-p) which is mounted on the Torun 32-m telescope. The clusters (Cl0016+16, MS0451.6-0305, MS1054.4-0321 and Abell 2218) are popular SZ targets and serve as commissioning observations. All four are detected with clear significance (4-6 sigma) and values for the central temperature decrements are in good agreement with measurements reported in the literature. We believe that systematic effects are successfully suppressed by our observing strategy. The relatively short integration times required to obtain these results demonstrate the power of OCRA-p and its successors for future SZ studies.Comment: 9 pages, 2 figures. Accepted by MNRAS, online earl

Quantum Dot Bioconjugate Platforms for Analysis of Enzyme Activity

Quantum dots are semiconductor nanocrystals with size-dependent optical properties that result from their nanoscale dimensions. These materials are emerging as simpler and more sensitive alternatives to traditional fluorescent small molecules and radioactive reporters in biomarker assays. Quantum dot emission can be modulated via proximal binding of organic dyes or gold nanoparticles, which can form the basis of a sensor. Their multivalency and ease of functionalisation allow for the attachment of multiple biosensing ligands, boosting the detection sensitivity. Quantum dots with different emission wavelengths can be excited simultaneously and distinguished from one another spectrally, a property which can be used for multiplexing. Enzymes mediate the chemical modification of proteins thereby controlling the signalling cascades that regulate cell behaviour. Hence, aberrant activity of enzymes can be associated with the onset of disease. Clinical tests typically determine the total concentration of enzyme in a sample without regard to quantification of activity. In this thesis, the development of generic activity-dependent tests for acetyltransferases, kinases and proteases is described. Enzyme activity is reported via decoration of quantum dots with enzyme substrate peptides and subsequent binding of FRET acceptor dye-labelled antibodies, which mediate changes in quantum dot emission spectra. Using this platform, p300 histone acetyltransferase was detected with a limit of detection comparable to that of radiolabelling assays. Modifications of the platform to detect serine and tyrosine phosphorylation were investigated. The phosphotyrosine assay was combined with a gold nanoparticle-quantum dot assay for the detection of a kinase/protease biomarker pair relevant for the determination of breast cancer prognosis. The modular nature of this assay design allowed for the detection of different classes of enzymes singly and simultaneously, representing a generic platform for high-throughput enzyme screening in rapid disease diagnosis and drug discovery

Trigger sequence can influence final morphology in the self-assembly of asymmetric telechelic polymers

We report on a numerical study of polymer network formation of asymmetric biomimetic telechelic polymers with two reactive ends based on a self-assembling collagen, elastin or silk-like polypeptide sequence. The two reactive ends of the polymer can be activated independently using physicochemical triggers such as temperature and pH. We show, using a simple coarse grained model that the order in which this triggering occurs influences the final morphology. For both of collagen-silk and elastin-silk topologies we find that for relatively short connector chains the morphology of the assembly is greatly influenced by the order of the trigger, whereas for longer chains the equilibrium situation is more easily achieved. Moreover, self-assembly is greatly enhanced at moderate collagen interaction strength, due to facilitated binding and unbinding of the peptides. This finding indicates that both the trigger sequence and strength can be used to steer self-assembly in these biomimetic polymer systems.</p

Cosmos: The Infographic Book of Space

In writing 'Cosmos: The Infographic Book of Space' [1], we had the task of creating 100 infographic spreads spanning all of astronomy and space. From the solar system to cosmology and from space exploration to time dilation. The coverage is very broad. The same is true of the designs used through the book. With such a wide range of information, and to stop it getting repetitive, we used a huge variety of visual techniques. We also wanted to keep the book approachable. Some graphics are very simple, while others require more careful study. For each graphic we started from a topic. We then collated information or processed catalogues and databases. In some cases we did our own manual classification. We even asked for the help of the crowd! Once we had identified the key story we wanted to tell, we would create an initial draft. For data-driven designs, we did this with scripts written in perl, python or even javascript. We then worked with graphic designer Mark McCormick (Founded) to evolve each design to a final version. Working with both a designer and a publisher without physics backgrounds was invaluable in ensuring we presented the right message. We had several constraints in creating the book. One was the 'compressed' colour palette provided by the design aestheic. It is visually appealing but sometimes limited the information that we were able be convey. This, along with other constraints, led us to try different approaches. We learned a lot about producing infographics and presenting data to non-specialists. Our experience of data visualisation, together with Mark's eye for design and the latest scientific results, has created a book that has been well received by readers and critics. In this talk we will explain the methodology used to create the graphics. We will describe the lessons we learned in how to create successful infographics - as well as how not to! [1] S Lowe & C North (2015), Aurum Press Ltd, ISBN 178131450

Global Journalist: President Bush visits Africa

In this July 10, 2003 episode of Global Journalist, host Stuart Loory leads a discussion on President Bush's visit to Africa and his effort to alleviate the HIV/AIDS epidemic. Host: Stuart Loory. Guests: David Ouma Balikowa, Winston Ojukutu Macauley, David E. Ahaneku, Raymond Lowe. Directors: Pat Akers. Producers: Yusuf Kalyango, Sarah Katan