GLUV: A balloon-borne high-cadence ultraviolet monitoring telescope for supernova shock breakouts and exoplanet atmospheres

Routine photometric monitoring at near-ultraviolet wavelengths (< 400 nm) is compromised from the ground due to highly variable atmospheric transmission and cloud cover. The GLUV project will mount a modest sized telescope (200 mm primary) on a series of long-duration high-altitude balloon flights. The wide field camera (∼7 deg 2) will perform high cadence (10-300 second rolling integrations) each night for campaign durations of three to six months. The principle science mission is the early-time detection of supernova shock-breakout at near-ultraviolet wavelengths. Additionally, early design analysis has shown the system is also able to probe the atmospheric composition of exoplanet atmospheres through the combination of UV transit measurements with ground-based measurements at longer wavelengths. In this presentation we consider the specifications for a long-duration balloon platform for such a mission, focusing on the necessary mission requirements (sensitivity, sky coverage, cadence etc.) and the available platform suitability. Particular attention is paid to platform flight altitude and atmospheric transmissio

The Australian Space Eye: studying the history of galaxy formation with a CubeSat

The Australian Space Eye is a proposed astronomical telescope based on a 6U CubeSat platform. The Space Eye will exploit the low level of systematic errors achievable with a small space based telescope to enable high accuracy measurements of the optical extragalactic background light and low surface brightness emission around nearby galaxies. This project is also a demonstrator for several technologies with general applicability to astronomical observations from nanosatellites. Space Eye is based around a 90 mm aperture clear aperture all refractive telescope for broadband wide field imaging in the i and z bands.Comment: 19 pages, 14 figures, submitted for publication as Proc. SPIE 9904, 9904-56 (SPIE Astronomical Telescopes & Instrumentation 2016

Authentication and authorisation in entrusted unions

This paper reports on the status of a project whose aim is to implement and demonstrate in a real-life environment an integrated eAuthentication and eAuthorisation framework to enable trusted collaborations and delivery of services across different organisational/governmental jurisdictions. This aim will be achieved by designing a framework with assurance of claims, trust indicators, policy enforcement mechanisms and processing under encryption to address the security and confidentiality requirements of large distributed infrastructures. The framework supports collaborative secure distributed storage, secure data processing and management in both the cloud and offline scenarios and is intended to be deployed and tested in two pilot studies in two different domains, viz, Bio-security incident management and Ambient Assisted Living (eHealth). Interim results in terms of security requirements, privacy preserving authentication, and authorisation are reported

Factors to Consider During Identification and Invitation of Individuals in a Multi-stakeholder Research Partnership

BACKGROUND: Health research teams increasingly partner with stakeholders to produce research that is relevant, accessible, and widely used. Previous work has covered stakeholder group identification. OBJECTIVE: We aimed to develop factors for health research teams to consider during identification and invitation of individual representatives in a multi-stakeholder research partnership, with the aim of forming equitable and informed teams. DESIGN: Consensus development. PARTICIPANTS: We involved 16 stakeholders from the international Multi-Stakeholder Engagement (MuSE) Consortium, including patients and the public, providers, payers of health services/purchasers, policy makers, programme managers, peer review editors, and principal investigators. APPROACH: We engaged stakeholders in factor development and as co-authors of this manuscript. Using a modified Delphi approach, we gathered stakeholder views concerning a preliminary list of 18 factors. Over two feedback rounds, using qualitative and quantitative analysis, we concentrated these into ten factors. KEY RESULTS: We present seven highly desirable factors: ‘expertise or experience’, ‘ability and willingness to represent the stakeholder group’, ‘inclusivity (equity, diversity and intersectionality)’, ‘communication skills’, ‘commitment and time capacity’, ‘financial and non-financial relationships and activities, and conflict of interest’, ‘training support and funding needs’. Additionally, three factors are desirable: ‘influence’, ‘research relevant values’, ‘previous stakeholder engagement’. CONCLUSIONS: We present factors for research teams to consider during identification and invitation of individual representatives in a multi-stakeholder research partnership. Policy makers and guideline developers may benefit from considering the factors in stakeholder identification and invitation. Research funders may consider stipulating consideration of the factors in funding applications. We outline how these factors can be implemented and exemplify how their use has the potential to improve the quality and relevancy of health research. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11606-022-07411-w

Bridging-hydride influence on the electronic structure of an [FeFe] hydrogenase active-site model complex revealed by XAES-DFT

[[abstract]]Two crystallized [FeFe] hydrogenase model complexes, 1 = (μ-pdt)[Fe(CO)2(PMe3)]2 (pdt = SC1H2C2H2C3H2S), and their bridging-hydride (Hy) derivative, [1Hy]+++ = [(μ-H)(μ-pdt)[Fe(CO)2 (PMe3)]2]+ (BF4−), were studied by Fe K-edge X-ray absorption and emission spectroscopy, supported by density functional theory. Structural changes in [1Hy]+++ compared to 1 involved small bond elongations (<0.03 Å) and more octahedral Fe geometries; the Fe–H bond at Fe1 (closer to pdt-C2) was [similar]0.03 Å longer than that at Fe2. Analyses of (1) pre-edge absorption spectra (core-to-valence transitions), (2) Kβ1,3, Kβ′, and Kβ2,5 emission spectra (valence-to-core transitions), and (3) resonant inelastic X-ray scattering data (valence-to-valence transitions) for resonant and non-resonant excitation and respective spectral simulations indicated the following: (1) the mean Fe oxidation state was similar in both complexes, due to electron density transfer from the ligands to Hy in [1Hy]+++. Fe 1s→3d transitions remained at similar energies whereas delocalization of carbonyl AOs onto Fe and significant Hy-contributions to MOs caused an [similar]0.7 eV up-shift of Fe1s→(CO)s,p transitions in [1Hy]+++. Fed-levels were delocalized over Fe1 and Fe2 and degeneracies biased to Oh–Fe1 and C4v–Fe2 states for 1, but to Oh–Fe1,2 states for [1Hy]+++. (2) Electron-pairing of formal Fe(d7) ions in low-spin states in both complexes and a higher effective spin count for [1Hy]+++ were suggested by comparison with iron reference compounds. Electronic decays from Fe d and ligand s,p MOs and spectral contributions from Hys,p→1s transitions even revealed limited site-selectivity for detection of Fe1 or Fe2 in [1Hy]+++. The HOMO/LUMO energy gap for 1 was estimated as 3.0 ± 0.5 eV. (3) For [1Hy]+++ compared to 1, increased Fed (x2 − y2) − (z2) energy differences ([similar]0.5 eV to [similar]0.9 eV) and Fed→d transition energies ([similar]2.9 eV to [similar]3.7 eV) were assigned. These results reveal the specific impact of Hy-binding on the electronic structure of diiron compounds and provide guidelines for a directed search of hydride species in hydrogenases.[[notice]]補正完畢[[journaltype]]國外[[ispeerreviewed]]Y[[booktype]]紙本[[booktype]]電子版[[countrycodes]]GB

Lessons learned from the 1st Ariel Machine Learning Challenge: Correcting transiting exoplanet light curves for stellar spots

The last decade has witnessed a rapid growth of the field of exoplanet discovery and characterisation. However, several big challenges remain, many of which could be addressed using machine learning methodology. For instance, the most prolific method for detecting exoplanets and inferring several of their characteristics, transit photometry, is very sensitive to the presence of stellar spots. The current practice in the literature is to identify the effects of spots visually and correct for them manually or discard the affected data. This paper explores a first step towards fully automating the efficient and precise derivation of transit depths from transit light curves in the presence of stellar spots. The primary focus of the paper is to present in detail a diverse arsenal of methods for doing so. The methods and results we present were obtained in the context of the 1st Machine Learning Challenge organized for the European Space Agency’s upcoming Ariel mission. We first present the problem, the simulated Ariel-like data and outline the Challenge while identifying best practices for organizing similar challenges in the future. Finally, we present the solutions obtained by the top-5 winning teams, provide their code and discuss their implications. Successful solutions either construct highly non-linear (w.r.t. the raw data) models with minimal preprocessing –deep neural networks and ensemble methods– or amount to obtaining meaningful statistics from the light curves, constructing linear models on which yields comparably good predictive performance

Dual-purpose space simulation facility for plasma thruster and satellite testing

The Space Simulation Facility (S2F) is a dual purpose system designed to conduct plasma thruster testing and thermal vacuum qualification of satellites and instrumentation. Commissioned in 2013 at the Australian National University's Advanced Instrumentation and Technology Centre (AITC), the S2F brings a diverse range of new measurement capabilities to Australia. The S2F is a Dynavac-built system capable of thermal cycling from -170°C to +150°C at 3°C/min average ramp rate. A removable platen and shroud assembly accommodates test articles up to 500 kg with volumes up to 1.6m × 1.6m × 2.25m. A plume capture system and moveable 1.2 m long chamber annulus allows for plasma thruster test and diagnostic configurations up to 1.6m × 1.6m × 2.2m with offline thruster installation capability. The S2F system is capable of pumping from atmosphere to a pressure below 1E-5 Torr in less than eight hours. Twenty-five available thermocouple channels and 33 test unit readings allow for detailed test article monitoring and data collection. The S2F was conceived for maximum flexibility and the ability to support a wide range of projects well into the future. Initial supported projects include instrumentation evaluation for the Giant Magellan Telescope, the Australian Plasma Thruster, and three Australian CubeSats. Here we will present a detailed overview of the project goals and design considerations, as well as the initial test projects undertaken in S2F

Reproducible bubble-induced acoustic microstreaming for bead disaggregation and immunoassay in microfluidics

The bead-based immunoassay requires not only efficient mixing but also good control of bead-surface-area-to-sample-volume ratio to realise accurate and reproducible detection of low concentration samples. This paper reports the development of a microfluidic platform with the reproducible and efficient bubble-induced micromixing for bead disaggregation and immunoassay of prostate-specific antigen (PSA). The platform consists of a microfluidic chip with a microchamber and rectangular traps for capturing air bubbles and a home-made controller to generate sound wave using an external piezo transducer. Methods for reproducible bubble formation and bubble size control during mixing are explored. The influence of driving voltage, PDMS thickness and the substrate material on the mixing efficiency is characterised by mixing a fluorescence dye and a buffer solution. The optimised acoustic microstreaming is able to break clusters with hundreds of beads and homogenise individual beads over the microchamber. Immunoassay with efficient micromixing has been applied to PSA immunoassay with greatly reduced detection time. This study provides a practical guide for the design and development of the bubble-induced acoustic micromixers for bead disaggregation and on-chip immunoassays

High-Altitude airborne platform characterisation of adaptive optic corrected ground based laser

Adaptive optics can be used for more than astronomical imaging with large telescopes. The Research School of Astronomy and Astrophysics (RSAA) and the Space Environment Management Research Centre (SERC) at the Mount Stromlo Observatory in Canberra, Australia, have been developing adaptive optics (AO) for space environment management. Turbulence in the atmosphere causes optical signals to become degraded during propagation, which reduces the effective aperture of your transmitting or receiving telescope. An AO system measures and corrects for the turbulence in the atmosphere, allowing for greater resolution of optical signals. AO can be used to correct a laser beam propagating from the ground into space, or high-altitude airborne platform. The AO system performance depends heavily on the chosen site and system design. In order to properly design and implement a cost-effective AO system to propagate a laser into orbit, we propose using high-altitude platforms to measure AO system performance directly as a precursor in-orbit measurements. SERC plan on demonstrating remote manoeuvre of an orbiting object using photon pressure from an AO corrected high power ground based laser. The manoeuvre target will be a suitable piece of debris, or a dedicated satellite mission which is instrumented and tracked to measure the applied photon pressure and resulting orbit perturbation. High-altitude airborne platforms such as weather balloons or UAVs enable us to efficiently de-risk elements of this program by validating our numerical simulations of AO system performance with actual measurements. We are then able to confidently move towards in-orbit measurement of an AO corrected ground based laser, and remote manoeuvre with photon pressure. We present simulations along with experimental results for the development of array detectors which can be used to directly measure AO system performance