Spin-dependent recombination of photo-generated carriers at silicon surfaces

Imperial Users onl

Tablet-Based Mobile GIS Approaches to Archaeological Data Collection

Over the past 15 years, archaeological research in northern Armenia has documented the unique evolution of prehistoric complex societies in the South Caucasus, where complex, fortress-centered institutions emerged during the Late Bronze Age (c.1500-1150 BC) not from settled farming villages—as is more typical of archaic states—but from mobile herding communities. As the costs of archaeological fieldwork continue to rise, resulting in shorter and more intensive field seasons, researchers are leveraging new technologies to improve the efficiency and accuracy of data collection in the field. An increasingly popular solution in archaeology is the use of “paperless” site recording strategies that enhance the quality and effiency of data collection by limiting the potential for human error in transfering data from paper forms into a digital format; allowing project leaders to track the accuracy of data entry in real time and correct potential problems in the field; and tracking the transect lines of crew members to ensure greater scientific accuracy in sampling a survey area. This talk will focus on the cenceptual and technical aspects of a new mobile GIS system, developed in collaboration with Dr. Nicole Kong, that allows crew members to record sites directly into iPads with ESRI’s Collector for ArcGIS app and remotely linked via cellular connection to the project geodatabase hosted on a Purdue Library server. I will highlight the benefits and challenges of the new system encountered during a summer 2014 pilot survey in Armenia in anticipation of a full-scale survey planned for summer 2015

An Analysis of HCN Observations of The Galactic Centre's Circumnuclear Disk

The Circumnuclear Disk (CND) is a torus of dust and moleular gas rotating about the galactic centre and extends from 1.6 to 7pc from the central massive black hole SgrA*. Large Velocity Gradient modelling of selected transitions of HCN rotational collisions with molecular hydrogen is used to infer Hydrogen density and HCN opacities. The analysis concludes that the predicted hydrogen number density of CND clumps is about 10^6 which is insufficiently dense to withstand the tidal shear forces generated by SgrA* and the stellar group in the cavity between the galactic centre and the CND.Comment: A 107 page research thesis for the award of Master of Philosophy from the department of Physics and Astronomy at Macquarie University, Sydney, Australia. 31 figure

Dueling Electrospray Implemented on a Traveling-Wave Ion Mobility/Time-Of-Flight Mass Spectrometer: Towards a Gas-Phase Workbench for Structural Biology

• Covalent chemistry was performed in an ion mobility/mass spectrometer (IM/MS). • The effects of various parameters on the extent of reactions was observed. • Angiotensin I and ubiquitin were covalently labeled in the gas-phase. • Ion/ion reactions modify ions with solution-like conformations.The traveling wave trap cell of a commercial ion mobility mass spectrometer (IM/MS) was used as a gas-phase reactor for covalent chemistry by making a simple modification to a standard nanoelectrospray source. Reagents and analytes were generated from pulsed opposite polarity nanoelectrospray sources and isolated by their m/z prior to reaction. Covalent bond formation was first observed with the model peptide angiotensin I. The modification site was identified as the N-terminus of the peptide by collision induced dissociation (CID). The IM cell separated the covalent reaction product from the proton transfer product by their respective ion mobilities. Next, the effects of several trapping parameters, including the trap traveling wave height, the trap RF voltage, and the trap pressure, were evaluated. Decreasing traveling wave height and increasing RF voltage and pressure increased the number of proton transfer events from apomyoglobin to reagent anions. The 6+ charge state of ubiquitin generated from nanospray under native-like conditions was covalently modified in the gas phase through ion/ion reactions. Probing the reacted protein with CID led to the assignment of lysine 29 and arginine 54 as reactive nucleophiles accessible to the reagent. IM analysis of the unmodified native-like 6+ charge state revealed that the gas-phase structure of the protein in the trap was in its compact form. Overall, we introduce a promising method for three-dimensional structural characterization of biomacromolecules

Incoherently pumped continuous wave optical parametric oscillator broadened by non-collinear phasematching

In this paper, we report on a singly resonant optical parametric oscillator (OPO) pumped by an amplified spontaneous emission (ASE) source. The pump focusing conditions allow non-collinear phasematching, which resulted in a 230 nm (190 cm$^{-1}$) spectral bandwidth. Calculations indicate that such phasematching schemes may be used to further broaden OPO spectral bandwidths.Comment: 7 pages 4 figure

The Australian corporate closet, why it\u27s still so full: a review of incidence rates for sexual orientation discrimination gender identity discrimination in the workplace

The paper reviews the extant Australian literature on sexual orientation (SO) discrimination within the Australian workplace. In the research, there is variation in organisational workplace and a bias towards health and educational sectors as a research setting, which raises some methodological considerations such as poor generalisability to other organisational contexts. The small body of Australian research into SO discrimination encompasses; (i) varied methodological and theoretical approaches, (ii) disparate authors selecting a varied range of aspects of discrimination thus absenting a unifying framework to guide research and lacking as yet seminal authorship providing focus, iii) limited sampling of participants making comparisons difficult and further indicating the absence of a unifying framework with which to focus the research and iv) limited studies exclusively investigating workplace discrimination. In this paper, the Australian literature is presented chronologically, and where possible, it has linked studies together to indicate the commensurate nature of the studies to illustrate the incidence rates of SO discrimination in the Australian labour market as a rationale for GLBTIQ employees remaining in the corporate closet

Homophobia to heterosexism: constructs in need of re-visitation

Although the concept of homophobia has been used extensively in the literature since the early 1960s, researchers have shown growing concern for its relevance in present day research. Additionally, there has been variance in its definition leading to an array of ambiguities resulting in methodological limitations in empirical studies with a disregard for ensuring that definitions used match the focus of study. There have been numerous attempts to locate the construct within a theoretical framework and this has also resulted in weak empirical design. These weaknesses in research on homophobia have resulted in the coining of the construct heterosexism as a more contemporary and more appropriate definition than that of homophobia to indicate anti-gay discrimination. This review considers both terms with regard to their appropriateness and distinction and the utility of the construct heterosexism as it is applied to contemporary research on non-heterosexual communities. It is concluded that homophobia can no longer be framed as a straightforward function of individual psyches or irrational fear and loathing and that heterosexism is more appropriate in defining prejudiced behaviours and their consequences for non-heterosexual communities