Microscopic Surface Structure of Liquid Alkali Metals

We report an x-ray scattering study of the microscopic structure of the surface of a liquid alkali metal. The bulk liquid structure factor of the eutectic K67Na33 alloy is characteristic of an ideal mixture, and so shares the properties of an elemental liquid alkali metal. Analysis of off-specular diffuse scattering and specular x-ray reflectivity shows that the surface roughness of the K-Na alloy follows simple capillary wave behavior with a surface structure factor indicative of surface induced layering. Comparison of thelow-angle tail of the K67Na33 surface structure factor with the one measured for liquid Ga and In previously suggests that layering is less pronounced in alkali metals. Controlled exposure of the liquid to H2 and O2 gas does not affect the surface structure, indicating that oxide and hydride are not stable at the liquid surface under these experimental conditions.Comment: 12 pages, 3 figures, published in Phys. Rev.

Commercializing Biomedical Research Through Securitization Techniques

Biomedical innovation has become riskier, more expensive and more difficult to finance with traditional sources such as private and public equity. Here we propose a financial structure in which a large number of biomedical programs at various stages of development are funded by a single entity to substantially reduce the portfolio's risk. The portfolio entity can finance its activities by issuing debt, a critical advantage because a much larger pool of capital is available for investment in debt versus equity. By employing financial engineering techniques such as securitization, it can raise even greater amounts of more-patient capital. In a simulation using historical data for new molecular entities in oncology from 1990 to 2011, we find that megafunds of $5–15 billion may yield average investment returns of 8.9–11.4% for equity holders and 5–8% for 'research-backed obligation' holders, which are lower than typical venture-capital hurdle rates but attractive to pension funds, insurance companies and other large institutional investors

Fermi Surface reconstruction in the CDW state of CeTe3 observed by photoemission

CeTe3 is a layered compound where an incommensurate Charge Density Wave (CDW) opens a large gap (400 meV) in optimally nested regions of the Fermi Surface (FS), whereas other sections with poorer nesting remain ungapped. Through Angle-Resolved Photoemission, we identify bands backfolded according to the CDW periodicity. They define FS pockets formed by the intersection of the original FS and its CDW replica. Such pockets illustrate very directly the role of nesting in the CDW formation but they could not be detected so far in a CDW system. We address the reasons for the weak intensity of the folded bands, by comparing different foldings coexisting in CeTe3

Atomic-scale surface demixing in a eutectic liquid BiSn alloy

Resonant x-ray reflectivity of the surface of the liquid phase of the Bi$_{43}$Sn$_{57}$ eutectic alloy reveals atomic-scale demixing extending over three near-surface atomic layers. Due to the absence of underlying atomic lattice which typically defines adsorption in crystalline alloys, studies of adsorption in liquid alloys provide unique insight on interatomic interactions at the surface. The observed composition modulation could be accounted for quantitatively by the Defay-Prigogine and Strohl-King multilayer extensions of the single-layer Gibbs model, revealing a near-surface domination of the attractive Bi-Sn interaction over the entropy.Comment: 4 pages (two-column), 3 figures, 1 table; Added a figure, updated references, discussion; accepted at Phys. Rev. Let

Anomalous layering at the liquid Sn surface

X-ray reflectivity measurements on the free surface of liquid Sn are presented. They exhibit the high-angle peak, indicative of surface-induced layering, also found for other pure liquid metals (Hg, Ga and In). However, a low-angle peak, not hitherto observed for any pure liquid metal, is also found, indicating the presence of a high-density surface layer. Fluorescence and resonant reflectivity measurements rule out the assignment of this layer to surface-segregation of impurities. The reflectivity is modelled well by a 10% contraction of the spacing between the first and second atomic surface layers, relative to that of subsequent layers. Possible reasons for this are discussed.Comment: 8 pages, 9 figures; to be submitted to Phys. Rev. B; updated references, expanded discussio

Evaluating In-house Work Integrated Learning Experiences Using the Business Model Canvas

CONTEXT The school of Professional Practice and Leadership at UTS set up Optik Consultancy to provide students unable to access internships, with engineering projects set up by industry partners in a simulated workplace. In 2021, in the midst of the COVID-19 crisis, 120 students (85 international and 35 domestic) completed Work Integrated Learning (WIL) in this manner. This was the 5th iteration of the project with the number of students increasing each year. This model has the potential to be extended to other groups such as refugees needing existing qualifications validated, or engineers returning to the workplace after an extended absence. To do this successfully, it is necessary to ensure the program meets participants’ requirements. This requires recognition of the complexity of the program and the development of a framework to ensure all elements that make a successful program are in place. PURPOSE OR GOAL This paper analyses the Optik Consultancy through the lens of the ‘Business Model Canvas’ (Osterwalder & Pigneur (2010). As illustrated by Kline et al (2017), this framework can be adapted to design a template to meet the specific needs of educational projects. We aim to analyse the main activities and processes of the Optik Consultancy and redesign the Business Model Canvas for WIL engineering projects to identify the elements necessary for designing a similar project in other settings. APPROACH Firstly, we will investigate the Optik Consultancy through the lens of the ‘Business Model Canvas. This will enable us to identify key areas relevant to a simulated internship program in order to form an engineering WIL canvas. This canvas will explain what we do, how we do it and why. We will then apply our new canvas to the Optik Consultancy to see how far it conforms to our template. Finally, we will conceptualise a new canvas that can be replicated as a template for setting up similar programs in other disciplines. ACTUAL OR ANTICIPATED OUTCOMES By analysing the Optik Consultancy through the lens of an adapted Business Model Canvas, we will assess the key areas of our program from a different viewpoint. This will include justification of the program, the stakeholders involved, their needs and level of involvement, and the resources needed to make the program a success. Once this template has been established, we will have a conceptual tool that can be used to set up and analyse other WIL programs. CONCLUSIONS With some adaptations, the business model canvas can be applied to evaluate engineering WIL programs and provide a template to extend and review similar activities. To ensure that the model is applied accurately, further research will be necessary to evaluate the extent each area of the framework has been achieved

Charge density wave formation in R2R_{2}Te5_{5} (RR=Nd, Sm and Gd)

The rare earth ($R$) tellurides $R_2$Te$_5$ have a crystal structure intermediate between that of $R$Te$_2$ and $R$Te$_3$, consisting of alternating single and double Te planes sandwiched between $R$Te block layers. We have successfully grown single crystals of Nd$_2$Te$_5$, Sm$_2$Te$_5$ and Gd$_2$Te$_5$ from a self flux, and describe here the first evidence for charge density wave formation in these materials. The superlattice patterns for all three compounds are relatively complex, consisting at room temperature of at least two independent wavevectors. Consideration of the electronic structure indicates that to a large extent these wave vectors are separately associated with sheets of the Fermi surface which are principally derived from the single and double Te layers.Comment: 10 pages, 6 figure