SARS-related Virus Predating SARS Outbreak, Hong Kong

Using immunofluorescence and neutralization assays, we detected antibodies to human severe acute respiratory syndrome–associated coronavirus (SARS-CoV) and/or animal SARS-CoV–like virus in 17 (1.8%) of 938 adults recruited in 2001. This finding suggests that a small proportion of healthy persons in Hong Kong had been exposed to SARS-related viruses at least 2 years before the recent SARS outbreak

Effectiveness of jet location on mixing characteristics inside a cavity in supersonic flow

The incorporation of cavities within supersonic combustion chambers is an effective means of slowing down the flow for fuel injection and consequent stable combustion. Understanding the flow physics associated with such flows, especially with the injection of a gas to replicate fuel injection, are essential for the optimum design of supersonic propulsion mechanisms. An experimental investigation was performed on a rectangular open cavity with upstream injection model in a Mach number of 1.9 using a trisonic indraft wind tunnel. A rectangular open cavity of dimensions L/D = 5, 100 mm in length (L) and 20 mm deep (D), was adopted, and it was embedded into the lower wall of the test section. An air jet with a jet-to-freestream momentum flux ratio of J = 1.2, 2.7 and 5.3 was injected upstream of the cavity. To evaluate the effect on mixing and flow stability the jet position, measured from the front edge of the cavity, was varied between 0.1L and 1L. The flow field was visualized using schlieren photography, particle image velocimetry, and oil flow measurements. It is found that the mixing characteristic within the cavity when the jet is positioned 0.1L is enhanced independent on the J value because the turbulence intensity of the flow velocity within the cavity is strongly influenced by the jet interaction which lifted the flow from the floor of the cavity compared to the other jet positions. However, the flow over the cavity is unstable at all jet positions. The separation shock formed at the front edge of the cavity oscillates significantly for the case where the jet is located at 0.1L because the separation shock location coincides with the compression shock behind the jet

Integrated policymaking is needed to deliver climate and ecological benefits from solar farms

1. Multi-purpose land use is of great importance for sustainable development, particularly in the context of increasing pressures on land to provide ecosystem services (e.g. food, energy) and support biodiversity. 2. The recent global increase in land-take for utility-scale ground-mounted solar farms (hereafter referred to as solar farms) to meet Net Zero targets presents an opportunity for enhanced delivery of ecosystem services, especially in temperate ecosystems where solar farm development often results in land use change away from comparatively intensive agricultural land management. Solar farms have long operational lifespans, experience low levels of disturbance during operation and can be managed for ecosystem services beyond low-carbon electricity generation, including food production and biodiversity conservation. 3. Here, we briefly synthesise the mechanisms by which solar farm development and operation may impact natural capital and ecosystem services, and provide policy recommendations for policymakers and the solar farm sector. 4. Solar farms can deliver environmental benefits for hosting ecosystems while minimising negative impacts, with outcomes depending on location, construction techniques, and land management practices. However, the historical misalignment between climate, nature, and land use policies has hindered efforts to simultaneously address the climate and biodiversity crises through land use change for solar farms. For instance, existing public financial incentives in the UK that encourage landowners and developers to manage land for biodiversity largely exclude land with solar farms. 5. Policy implications: We call for public policymakers to identify appropriate opportunities to amend existing national laws that address climate and biodiversity separately to improve integration of multiple aspects of the climate-nature-land use nexus into policymaking by: (1) formulating ecological and socio-economic indicators and metrics that are appropriate to underpin the development, implementation, and assessment of public policies; (2) adopting a cross-sectoral and cross-government approach to form public policies; (3) ensuring solar farms can access public financial incentives that encourage sustainable land use; (4) implementing land use policies that incentivise funding from non-government sources (e.g. private sector) into nascent nature markets; (5) embedding solar farms in biodiversity-inclusive spatial planning policies and decision-making; and (6) building equity and clarity into responsibilities and benefits for all actors involved

Effects of dual jets distance on mixing characteristics and flow path within a cavity in supersonic crossflow

A rectangular open cavity with upstream dual injectors at a freestream Mach number of 1.9 was investigated experimentally. To evaluate the effect of the distance between the jets, the flow characteristics were investigated using the high-speed schlieren photography, particle image velocimetry, and surface oil flow techniques. The dual jet distances of 18 and 54 mm were used. Unstable flow occurs over the cavity in all cases and is not improved by changing the distance between the dual jets. Although the distance between the dual jets does not influence the flow stability, the flow field varies decidedly depending on the dual jets distance. The enhancement of air mixing depends on the distance between the jets. A long dual jets distance was found to yield better mixing characteristics within the cavity than a short one. When the jets are further apart, the mainstream between two counter-rotating vortex pairs behind the jets flows strongly into the cavity because of the increased blow-down occurring between the vortex pairs. Additionally, a counterflow with a low velocity magnitude occurs behind the jets. Hence, mixing is enhanced within the cavity by effects of the opposed flow. When the jet pairs are closer to each other, the counter-rotating vortex pairs are in contact; as a result, the blow-down effect does not occur between them. The flow drawn into the cavity from the mainstream is supplied from the sides of the test section into the cavity

Smart robotic companion for the elderly 2.0 = 長者「智」友2.0

The first generation of the Smart Robotic Companion debuted in InnoCarnival 2015. After continuous refinement and improvement, the “Smart Robotic Companion for the Elderly 2.0” has been formally launched. Version 2.0 continues to play to its strength as a “health-monitor” for the elderly. Instead of appearing in a robot mode, version 2.0 can be installed on a tablet. The production cost of the upgraded version has been significantly reduced and the product is more affordable than before thus benefitting more aged users

An enhancement of the ionospheric sporadic‐E layer in response to negative polarity cloud‐to‐ground lightning

Lightning data, collected using a Boltek Storm Tracker system installed at Chilton, UK, were used to investigate the mean response of the ionospheric sporadic-E layer to lightning strokes in a superposed epoch study. The lightning detector can discriminate between positive and negative lightning strokes and between cloud-to-ground ( CG) and inter-cloud ( IC) lightning. Superposed epoch studies carried out separately using these subsets of lightning strokes as trigger events have revealed that the dominant cause of the observed ionospheric enhancement in the Es layer is negative cloud-to-ground lightning