Success of blinding a procedural intervention in a randomised controlled trial in preterm infants receiving respiratory support

Background: Blinding of treatment allocation from treating clinicians in neonatal randomised controlled trials can minimise performance bias, but its effectiveness is rarely assessed. // Methods: To examine the effectiveness of blinding a procedural intervention from treating clinicians in a multicentre randomised controlled trial of minimally invasive surfactant therapy versus sham treatment in preterm infants of gestation 25–28 weeks with respiratory distress syndrome. The intervention (minimally invasive surfactant therapy or sham) was performed behind a screen within the first 6 h of life by a ‘study team’ uninvolved in clinical care including decision-making. Procedure duration and the study team’s words and actions during the sham treatment mimicked those of the minimally invasive surfactant therapy procedure. Post-intervention, three clinicians completed a questionnaire regarding perceived group allocation, with the responses matched against actual intervention and categorised as correct, incorrect, or unsure. Success of blinding was calculated using validated blinding indices applied to the data overall (James index, successful blinding defined as > 0.50), or to the two treatment allocation groups (Bang index, successful blinding: −0.30 to 0.30). Blinding success was measured within staff role, and the associations between blinding success and procedural duration and oxygenation improvement post-procedure were estimated. // Results: From 1345 questionnaires in relation to a procedural intervention in 485 participants, responses were categorised as correct in 441 (33%), incorrect in 142 (11%), and unsure in 762 (57%), with similar proportions for each of the response categories in the two treatment arms. The James index indicated successful blinding overall 0.67 (95% confidence interval (CI) 0.65–0.70). The Bang index was 0.28 (95% CI 0.23–0.32) in the minimally invasive surfactant therapy group and 0.17 (95% CI 0.12–0.21) in the sham arm. Neonatologists more frequently guessed the correct intervention (47%) than bedside nurses (36%), neonatal trainees (31%), and other nurses (24%). For the minimally invasive surfactant therapy intervention, the Bang index was linearly related to procedural duration and oxygenation improvement post-procedure. No evidence of such relationships was seen in the sham arm. // Conclusion: Blinding of a procedural intervention from clinicians is both achievable and measurable in neonatal randomised controlled trials

The importance of weather and climate to energy systems: a workshop on next generation challenges in energy-climate modelling

Over 80 international participants, representing weather, climate, and energy systems research, joined two 4-hour remote sessions to highlight and prioritize ongoing and future challenges in energy-climate modelling. The workshop had two primary goals: to build a deeper engagement across the “energy” and “climate” research communities, and to identify and begin to address the scientific challenges associated with modelling climate risk in energy systems

The Optimal Infrastructure Design for Grid-to-Vehicle (G2V) Service: A Case Study Based on the Monash Microgrid

The electrification of the transport sector has emerged as a game changer in addressing the issues of climate change caused by global warming. However, the unregulated expansion and simplistic approach to electric vehicle (EV) charging pose substantial risks to grid stability and efficiency. Intelligent charging techniques using Information and Communication Technology, known as smart charging, enable the transformation of the EV fleets from passive consumers to active participants within the grid ecosystem. This concept facilitates the EV fleet’s contribution to various grid services, enhancing grid functionality and resilience. This paper investigates the optimal infrastructure design for a smart charging system within the Monash microgrid (Clayton campus). We introduce a centralized Grid-to-Vehicle (G2V) algorithm and formulate three optimization problems utilizing linear and least-squares programming methods. These problems address tariff structures between the main grid and microgrid, aiming to maximize aggregator profits or minimize load fluctuations while meeting EV users’ charging needs. Additionally, our framework incorporates network-aware coordination via the Newton–Raphson method, leveraging EVs’ charging flexibility to mitigate congestion and node voltage issues. We evaluate the G2V algorithm’s performance under increasing EV user demand through simulation and analyze the net present value (NPV) over 15 years. The results highlight the effectiveness of our proposed framework in optimizing grid operation management. Moreover, our case study offers valuable insights into an efficient investment strategy for deploying the G2V system on campus

Evaluation of vinylidene fluoride polymers for use in space environments: Comparison of radiation sensitivities

Poly(vinylidene fluoride) and copolymers of vinylidene fluoride with hexafluoropropylene, trifluoroethylene and chlorotrifluoroethylene have been exposed to gamma irradiation in vacuum, up to doses of 1MGy under identical conditions, to obtain a ranking of radiation sensitivities. Changes in the tensile properties, crystalline melting points,heats of fusion, gel contents and solvent uptake factors were used as the defining parameters. The initial degree of crystallinity and film processing had the greatest influence on relative radiation damage, although the cross-linked network features were almost identical in their solvent swelling characteristics, regardless of the comonomer composition or content

Effect of simulated space environments on piezoelectric vinylidene fluoride-based polymers

Piezoelectric polymers based on polyvinylidene flouride (PVDF) are of interest as adaptive materials for large aperture space-based telescopes. In this study, two piezoelectric polymers, PVDF and P(VDF-TrFE), were exposed to conditions simulating the thermal, radiative and atomic oxygen conditions of low Earth orbit. The degradation pathways were governed by a combination of chemical and physical degradation processes with the molecular changes primarily induced via radiative damage, and physical damage from temperature and atomic oxygen exposure, as evident from depoling, loss of orientation and surface erosion. The piezoelectric responsiveness of each polymer was strongly dependent on exposure temperature. Radiation and atomic oxygen exposure caused physical and chemical degradation, which would ultimately cause terminal damage of thin films, but did not adversely affect the piezoelectric properties

Power system decarbonisation with Global Energy Interconnection – a case study on the economic viability of international transmission network in Australasia

The electric energy system in Indonesia is undergoing with the challenges of fast-increasing electricity demand, carbon constraints, and rising costs. Using our model of the Australian and Indonesian electrical grids (either separately or interconnected) that incorporates operational flexibility in capacity expansion planning, we first show that meeting the projected demand for Java and Bali—the main Indonesian grid, with 100% locally integrated renewables by 2050 would be challenging. However, a submarine high-voltage DC (HVDC) link connecting Indonesia’s Java-Bali power grid to the Australian National Electricity Market (NEM) grid through the Northern Territory would help alleviate this situation, given Australia’s abundant renewable energy resources. Then, our model reveals that the Australian NEM could also profit from additional renewables if connected to the Northern Territory through a ground HVDC transmission line to gather intermittent wind and solar generation, which would be curtailed otherwise if unused by Indonesia through the submarine link. Despite the expensiveness of long HVDC links, the wholesale electricity cost of the integrated 100% renewable Australasia power system could be reduced by over 16%, from $AUD177/MWh with only local renewables to$AUD148/MWh with integrated HVDC transmission. The model retrieved the optimal international HVDC link with capacity of 43.8 GW, and the optimal regional HVDC transmission line with a capacity of 5.5 GW. To the best of our knowledge, this is the first detailed model on power system decarbonisation planning for both Australian NEM and Indonesian Java-Bali power grid considering HVDC interconnections. Keywords: Decarbonisation, Climate change mitigation, HVDC, Grid interconnectio

Estimating High Latitude Carbon Fluxes With Inversions Of Atmospheric CO 2

Global carbon cycle, atmospheric inversions, Boreal ecosystems,

Smart materials for gossamer spacecraft - Performance limitations

Smart polymeric materials, such as piezoelectric polymers which deform by application of an electric field, are of interest for use in controllable mirrors as large, lightweight space optics. An important consideration when using any organic material in a space application is their extreme vulnerability to the space environment. In LEO the presence of atomic oxygen, large thermal extremes, hard vacuum, short wavelength ultraviolet and particulate radiation can result in erosion, cracking and outgassing of most polymers. While much research has been performed examining the physical and chemical changes incurred by polymers exposed to actual and simulated LEO environments, little work has focused on the effects of the space environment on the performance of piezoelectric polymers. The most widely used piezoelectric polymers are those based on poly(vinylidene fluoride) (PVDF) and include copolymers synthesized from vinylidene fluoride and trifluoroethylene, hexafluoropropylene or chlorotrifluoroethylene. The presence of a comonomer group can greatly influence on the crystalline phase, melting point, Curie point, modulus and processing required for piezoelectricity. After a rigorous pre-selection process only two polymers, namely the PVDF homopolymer and a TrFE copolymer (80% comonomer content), satisfied most of the requirements for operation in the temperature/radiation environment of LEO. Based on this initial materials selection, we have now performed a detailed study of the effects of temperature, atomic oxygen and vacuum UV radiation simulating low Earth orbit conditions on these two polymers. Both polymers exhibited diminished but very stable piezoelectric performance up to 130°C despite the upper use temperatures suggested by industry of 80°C (PVDF) and 100°C (P(VDF-TrFE)). We believe that the loss of piezoelectric response in samples conditioned at 130°C compared with non-exposed samples is partly due to the depoling process which occurs when the highly stressed films undergo contraction via relaxation. The TrFE copolymer, which does not need to be stretched for the polar phase to be present, has better retention of piezoelectric properties at 130°C compared with the highly oriented homopolymer. AO/VUV exposure caused significant surface erosion and pattern development for both polymers. Erosion yields were 2.8×10-24 cm3/atom for PVDF and 2.5×10 -24 cm3/atom for P(VDF-TrFE). The piezoelectric properties of the residual material for both polymers were largely unchanged after exposure, although a slight shift in the Curie transition of the P(VDF-TrFE) was observed. A lightly crosslinked network was formed in the copolymer, presumably due to penetrating VUV radiation, while the homopolymer remained uncrosslinked. These differences were attributed to different levels of crystallinity and increased VUV absorption by P(VDF-TrFE) over PVDF. In this paper a summary of the performance limiting effects of temperature, radiation, atomic oxygen and VUV on the piezoelectric response of PVDF based polymers will be presented.</p