Passenger ride comfort technology for transport aircraft situations

A brief overview is given of NASA research in ride comfort and of the resultant technology. Three useful relations derived from the technology are presented together with five applications of these relations to illustrate their effectiveness in addressing various ride comfort situations of passenger transports

Exploring the high-pressure materials genome

A thorough in situ characterization of materials at extreme conditions is challenging, and computational tools such as crystal structural search methods in combination with ab initio calculations are widely used to guide experiments by predicting the composition, structure, and properties of high-pressure compounds. However, such techniques are usually computationally expensive and not suitable for large-scale combinatorial exploration. On the other hand, data-driven computational approaches using large materials databases are useful for the analysis of energetics and stability of hundreds of thousands of compounds, but their utility for materials discovery is largely limited to idealized conditions of zero temperature and pressure. Here, we present a novel framework combining the two computational approaches, using a simple linear approximation to the enthalpy of a compound in conjunction with ambient-conditions data currently available in high-throughput databases of calculated materials properties. We demonstrate its utility by explaining the occurrence of phases in nature that are not ground states at ambient conditions and estimating the pressures at which such ambient-metastable phases become thermodynamically accessible, as well as guiding the exploration of ambient-immiscible binary systems via sophisticated structural search methods to discover new stable high-pressure phases.Comment: 14 pages, 6 figure

Hard hexagon partition function for complex fugacity

We study the analyticity of the partition function of the hard hexagon model in the complex fugacity plane by computing zeros and transfer matrix eigenvalues for large finite size systems. We find that the partition function per site computed by Baxter in the thermodynamic limit for positive real values of the fugacity is not sufficient to describe the analyticity in the full complex fugacity plane. We also obtain a new algebraic equation for the low density partition function per site.Comment: 49 pages, IoP styles files, lots of figures (png mostly) so using PDFLaTeX. Some minor changes added to version 2 in response to referee report

Fin Fish (Stout Whiting) Trawl Fishery Level 1 Ecological Risk Assessment

The Queensland Ecological Risk Assessment Guideline (the Guideline) was released in March 2018 as part of the Queensland Sustainable Fisheries Strategy 2017–2027. This Guideline provides an overview of strategy being employed to develop Ecological Risk Assessments (ERAs) for Queensland’s fisheries. The Guideline describes a four-stage framework consisting of a Scoping Study; a Level 1, whole of fishery qualitative assessment; a Level 2, species-specific semi-quantitative or low-data quantitative assessment and; a Level 3 quantitative assessment (if applicable). The aim of the Level 1 ERA is to produce a broad risk profile for each fishery using a qualitative ERA method described by Astles et al. (2006). The method considers a range of factors including the current fishing environment (e.g. current catch, effort and licensing trends), limitations of the current management arrangements (e.g. transfer of effort to already saturated markets, substantial increases in fishing mortality for key species, changing target species) and life-history constraints of the species being assessed. In the Fin Fish Trawl Fishery the Level 1 ERA assessed fishing related risks in 15 ecological components including target & byproduct species, bycatch, marine turtles, sea snakes, crocodiles, dugongs, cetaceans, protected teleosts, batoids, sharks, syngnathids, seabirds, terrestrial mammals, marine habitats and ecosystem processes. Based on the outputs of the Level 1 ERA, the FFTF will not be progressed to Level 2 ERA. The Level 1 ERA identified knowledge gaps for bycatch and batoids, but these information needs will be progressed to the Fisheries Queensland Monitoring and Research Plan for further consideration

Spanner Crab Fishery Level 1 Ecological Risk Assessment

The Queensland Ecological Risk Assessment Guideline (the Guideline) was released in March 2018 as part of the Queensland Sustainable Fisheries Strategy 2017–2027. This Guideline provides an overview of strategy being employed to develop Ecological Risk Assessments (ERAs) for Queensland’s fisheries. The Guideline describes a four-stage framework consisting of a Scoping Study; a Level 1, whole of fishery qualitative assessment; a Level 2, species-specific semi-quantitative or low-data quantitative assessment and; a Level 3 quantitative assessment (if applicable). The aim of the Level 1 ERA is to produce a broad risk profile for each fishery based on a qualitative ERA method described by Astles et al. (2006). The method considers a range of factors including the current fishing environment (e.g. current catch, effort and licensing trends), limitations of the current management arrangements (e.g. transfer of effort to already saturated markets, substantial increases in fishing mortality for key species, changing target species) and life-history constraints of the species being assessed. In the Spanner Crab Fishery the Level 1 ERA assessed fishing related risks in 15 ecological components including target species, bycatch, marine turtles, sea snakes, crocodiles, dugongs, cetaceans (whales and dolphins), protected teleosts, batoids, sharks, syngnathids, seabirds, terrestrial mammals, marine habitats and ecosystem processes. The Level 1 ERA indicates that the Spanner Crab Fishery presents a low to negligible risk to most of ecological components. At low/intermediate, target species had the highest risk rating of the assessment. These risks are being managed effectively through a range of measures including a fishery-specific harvest strategy

Fin Fish (Stout Whiting) Trawl Fishery Scoping Study

The Queensland Ecological Risk Assessment Guideline (the Guideline) was released in March 2018 as part of the Queensland Sustainable Fisheries Strategy 2017–2027. This Guideline provides an overview of strategy being employed to develop Ecological Risk Assessments (ERAs) for Queensland’s fisheries. The Guideline describes a four-stage framework consisting of a Scoping Study; a Level 1, whole of fishery qualitative assessment; a Level 2, species-specific semi-quantitative or low-data quantitative assessment and; a Level 3 quantitative assessment (if applicable). The Scoping Study establishes a baseline of information on the key characteristics of the Fin Fish (Stout Whiting) Trawl Fishery (FTFF). It includes information on the broader management regime, key species, gear configurations and catch and effort trends. Information contained in the scoping study for the FTFF will be used to inform subsequent assessments including the whole of fishery (Level 1) and species-specific (Level 2)

Integrability vs non-integrability: Hard hexagons and hard squares compared

In this paper we compare the integrable hard hexagon model with the non-integrable hard squares model by means of partition function roots and transfer matrix eigenvalues. We consider partition functions for toroidal, cylindrical, and free-free boundary conditions up to sizes $40\times40$ and transfer matrices up to 30 sites. For all boundary conditions the hard squares roots are seen to lie in a bounded area of the complex fugacity plane along with the universal hard core line segment on the negative real fugacity axis. The density of roots on this line segment matches the derivative of the phase difference between the eigenvalues of largest (and equal) moduli and exhibits much greater structure than the corresponding density of hard hexagons. We also study the special point $z=-1$ of hard squares where all eigenvalues have unit modulus, and we give several conjectures for the value at $z=-1$ of the partition functions.Comment: 46 page

Crab Fishery Level 2 Ecological Risk Assessment

The Queensland Ecological Risk Assessment Guideline (the Guideline) was released in March 2018 as part of the Queensland Sustainable Fisheries Strategy 2017–2027. This Guideline provides an overview of strategy being employed to develop Ecological Risk Assessments (ERAs) for Queensland’s fisheries. The Guideline describes a four-stage framework consisting of a Scoping Study; a Level 1, whole of fishery qualitative assessment; a Level 2, species-specific semi-quantitative or low-data quantitative assessment and; a Level 3 quantitative assessment (if applicable). A Scoping Study and Level 1 ERA for the Mud & Blue Swimmer Crab Fishery was released in May 2019 (Walton & Jacobsen, 2019). The Level 1 assessment identified ecological components at higher risk from crab fishing activities, and these were progressed to a Level 2 assessment. Level 2 ERAs are focused at the species level with risk evaluations based on a Productivity & Susceptibility Analysis (PSA). The PSA evaluates risk for each species through an assessment of seven biological attributes and up to seven fisheries-specific attributes. Based on the outputs of the Level 1 ERA and following a species prioritisation process, the Level 2 ERA assessed risk for two target & byproduct species, six marine turtles and a single shark. Both target & byproduct species and four marine turtle species were found to be at low to moderate range risk from crab fishing activities. However, two marine turtles (green and loggerhead) and the shark (speartooth) were found to be at high risk. The risk profiles of these species were heavily influenced by the biological attributes (productivity); particularly those relating to their longevity and reproductive outputs. Other factors that increased the risk for these species included an increased encounterability potential and an elevated risk of post-interaction mortalities. The Level 2 ERA made a list of recommendations to assist in the management and mitigation of risk in the Crab Fishery. A number of these measures are already being discussed and considered as part of the Queensland Sustainable Fisheries Strategy 2017–2027 and will be progressed through the Crab Fishery Working Group

Gulf of Carpentaria Line Fishery Scoping Study

The Queensland Ecological Risk Assessment Guideline (the Guideline) was released in March 2018 as part of the Queensland Sustainable Fisheries Strategy 2017–2027. This Guideline provides an overview of strategy being employed to develop Ecological Risk Assessments (ERAs) for Queensland’s fisheries. The Guideline describes a four-stage framework consisting of a Scoping Study; a Level 1, whole of fishery qualitative assessment; a Level 2, species-specific semi-quantitative or low-data quantitative assessment and; a Level 3 quantitative assessment (if applicable). The Scoping Study establishes a baseline of information on the key characteristics of the Gulf of Carpentaria Line Fishery (GOCLF). It includes information on the broader management regime, key species, gear configurations and catch and effort trends. Information contained in the scoping study for the GOCLF will be used to inform subsequent assessments including the whole of fishery (Level 1) and species-specific (Level 2)

Root Fracture in Immature Tooth: Report of a Case

Root fracture injuries affect 0.5–7% of permanent teeth. Although this type of injury is rarely seen in teeth with immature root formation, the prognosis is generally good depending on the site of the fracture. A case report of horizontal root fracture in maxillary central incisor of an 8-year and 3-month-old girl and its treatment was presented