1,638 research outputs found

    Analyzing factors affecting Alaska's salmon permit values: evidence from Bristol Bay drift gillnet permits

    Get PDF
    Thesis (M.S.) University of Alaska Fairbanks, 2017The effects of total earnings, total costs and mining exploration on permit prices in Alaska are investigated using an autoregressive distributed lag (ARDL) approach to cointegration. I take specific account of regional and gear specific salmon fisheries -- that is, Bristol Bay drift gillnet permits -- in our modelling. I find that there is a stable long-run relationship among permit prices, total earnings, and total costs. It is also found that, in both the short- and long-run, total earnings have a positive and significant relationship with permit prices, while total costs have a negative and significant relationship. Although the mining exploration in the region has a negative and significant effect on permit prices in the short-run, the effect does not seem to last in the long-run

    Elastic stress concentration at radial crossholes in pressurised thick cylinders

    Get PDF
    Results of a parametric finite element analysis investigation of stress concentration at radial crossholes in pressurized cylinders are presented in numerical and graphical form. The analysis shows that the location of maximum stress does not generally occur at the junction between the bores, as is commonly supposed, but at some small distance up the crosshole from the junction. Maximum stress concentration factors (SCFs) are defined on the basis of the maximum principal stress, von Mises equivalent stress, and stress intensity. Three-dimensional plots of the SCF against the cylinder radius ratio b/a and the crosshole-to-main-bore-radius ratio c/a are presented. The SCFs were found to vary across the range of geometries considered with local minima identified within the parameter range in most cases. The results therefore allow designers to select optimum b/a and c/a ratios to minimize stress concentration in real problems

    New partnership network helps to protect Australian mangroves and saltmarsh.

    Get PDF
    MangroveWatch and the new Australian Mangrove and Saltmarsh Network are helping to link communities and promote information sharing to improve monitoring and management of coastal habitats

    Deployment of self-contained self rescuers in coal mines

    Get PDF
    Field trials at three New South Wales and one Queensland coal mines were carried out to gather data on oxygen .\u27run out times of Self-Contained Self Rescuers (SCSRs), time taken to escape from the mine, distances travelled and the average heart rate of subjects wearing SCSRs. The study has led to a method of predicting the duration of oxygen supply from a SCSR as a function of the wearer\u27s body weight. physical fitness and the prevailing environmental conditions. Escapeway design, planning for emergencies, familiarity with SCSRs and experiential escape training are critical to control panic and maxirnise the likelihood of survival of a person attempting to escape in an emergency involving fIre or explosion

    Design to Delivery of Additively Manufactured Propulsion Systems for the SWARM-EX Mission

    Get PDF
    Recent progress in miniaturized spacecraft propulsion technology has allowed for the development of complex, multi-vehicle missions which enable the cost-effective realization of science goals that would previously have been prohibitively expensive. The upcoming NSF-funded Space Weather Atmospheric Reconfigurable Multiscale EXperiment (SWARM-EX) mission leverages these swarm techniques to demonstrate novel autonomous formation flying capabilities while characterizing the spatial and temporal variability of ion-neutral interactions in the Equatorial Ionization Anomaly and Equatorial Thermospheric Anomaly. SWARM-EX will fly a trio of 3U CubeSats in a variety of relative orbits with along-track separations ranging from 3 km to 1300 km. To achieve the required orbital variability, the mission uses a novel hybrid approach of differential drag and an onboard cold gas propulsion system. Mission requirements necessitate a propulsion system that provides each spacecraft with 15 m/s of ∆V and a maximum thrust greater than 5 mN in a volume of roughly 0.7U (7 cm x 10 cm x 10 cm). Unlike many other CubeSat-scale cold gas propulsion systems which are used to provide attitude control and perform reaction wheel desaturation burns, the primary objective of the SWARM-EX propulsion system (SEPS) is to provide ∆V during maneuvers. The Georgia Institute of Technology Space Systems Design Laboratory (SSDL) is conducting the design, assembly, and testing of three identical SEPS. By leveraging additive manufacturing technology, the propellant tanks, nozzle, and tubing are combined into a single structure that efficiently utilizes the allocated volume. The propulsion system uses two-phase R-236fa refrigerant as a propellant, which allows for the storage of the majority of propellant mass as a liquid to maximize volumetric efficiency. The final design allows for 17 m/s of total ∆V per spacecraft and a measured maximum thrust of approximately 35 mN for short pulse lengths at room temperature. Each individual propulsion system has a volume under 0.5U (489 cm3), making them among the smallest formation-flying CubeSat-scale propulsion systems developed thus far. Owing to their two-phase propellant storage and single nozzle, the SEPS have a high impulse density (total impulse provided per unit of system volume) of 176 N-s/L. Additionally, process improvements to mitigate known failure modes such as propellant leaks and foreign object debris are implemented. This paper describes the entire design-to-delivery life cycle of the SWARM-EX propulsion units, including pertinent mission requirements, propulsion system design methodologies, assembly, and testing. Major lessons learned for future small satellite propulsive endeavors are also detailed

    Design of separating constructions that are resistant to the transmission of noise-part 2 - example details.

    Get PDF
    This document outlines example separating wall and floor construction details which when built correctly should comply with the sound insulation requirements as outlined in the proposed Section 5

    Design of separating constructions that are resistant to the transmission of noise-part 2 - example details.

    Get PDF
    This document outlines example separating wall and floor construction details which when built correctly should comply with the sound insulation requirements as outlined in the proposed Section 5

    Digital enablers for integrated care – a design workshop

    Get PDF
    In ‘Region A’, like in many other regions and countries, diabetes is a prevalent condition affecting one in twenty people. Type 2 diabetes is rapidly increasing in ‘Region A’, and currently accounts for about 87% of the cases in total. Diabetes has been recognized as an exemplar long term condition, both in terms of the growing number of people with type 2 diabetes, and in terms of the serious and expensive complications it can bring to the sufferers. Maintaining and improving the quality of diabetes services, according to the ‘Region A’s government, against the backdrop of increase in patient numbers and the increased pressure on the health and care services is one of the key challenges. Those involved in diabetes care include the individual, the carer, broader social groups, and public services at multiple levels. However, as with many condition groups, flow of information and decision making is often disjointed with poor communications between these players. The digital health and care innovation centre organised a multidisciplinary and inter-sectoral ecosystem event to explore the potential opportunities for better management of diabetes with a person centred approach. This event resulted in a call for innovation into digital solutions for managing diabetes. Seven project proposals were accepted by the Innovation Centre for further development. These seven projects offered partial solutions for the management of diabetes. As a result of the analysis of these projects, a comprehensive conceptual framework for connected health and care for the management of diabetes, has been developed. This conceptual framework has the potential to be applied to any other chronic care condition or multi conditions

    Immunostimulatory Membrane Proteins Potentiate \u3cem\u3eH. pylori-\u3c/em\u3eInduced Carcinogenesis by Enabling CagA Translocation

    Get PDF
    Infection with Helicobacter pylori is the single greatest risk factor for developing gastric adenocarcinoma. In prospective, population-based studies, seropositivity to the uncharacterized H. pylori proteins Hp0305 and Hp1564 was significantly associated with cancer risk in East Asia. However, the mechanism underlying this observation has not been elucidated. Here, we show that Hp0305 and Hp1564 act in concert with previously ascribed H. pylori virulence mechanisms to orchestrate cellular alterations that promote gastric carcinogenesis. In samples from 546 patients exhibiting premalignant gastric lesions, seropositivity to Hp0305 and Hp1564 was significantly associated with increased gastric atrophy across all stomach conditions. In vitro, depletion of Hp0305 and Hp1564 significantly reduced levels of gastric cell-associated bacteria and markedly impaired the ability of H. pylori to stimulate pro-inflammatory cytokine production. Remarkably, our studies revealed that Hp1564 is required for translocation of the oncoprotein CagA into gastric epithelial cells. Our data provide experimental insight into the molecular mechanisms governing novel H. pylori pathogenicity factors that are strongly associated with gastric disease and highlight the potential of Hp0305 and Hp1564 as robust molecular tools that can improve identification of individuals that are highly susceptible to gastric cancer. We demonstrate that Hp0305 and Hp1564 augment H. pylori-mediated inflammation and gastric cancer risk by promoting key bacteria-gastric cell interactions that facilitate delivery of oncogenic microbial cargo to target cells. Thus, therapeutically targeting microbial interactions driven by Hp0305/Hp1564 may enable focused H. pylori eradication strategies to prevent development of gastric malignancies in high-risk populations
    • …
    corecore