8,547 research outputs found

    Morphological budgeting in the Motueka River: an analysis of technique

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    Morphological budgeting is a key method for monitoring and studying sediment transfers within gravelly rivers. We assess the utility of traditional cross‐section approaches to budgeting using Digital Elevation Model (DEM) analysis. DEMs give a more accurate volume calculation within the constraint of sampling frequency compared with cross sections, since a greater area of river bed is sampled. DEM volume calculation within the 1.7 km ‘Three Beaches’ reach in the upper Motueka revealed a net loss of 3219 m3 in this reach between 2008‐2009. Comparisons of this value with cross section‐based volume calculations at a range of section spacing using (i) Mean Bed Level (MBL) analysis and (ii) DEMs generated from cross section data, suggest accuracy of the budget is maximised at a critical cross section spacing not exceeding 90 m. Careful positioning of cross sections could lengthen this distance further and is essential to accurately represent river channel morphology. MBL analysis using cross‐sections in the reach monumented by Tasman District Council (TDC) for river monitoring underestimates the magnitude of net sediment transfers by c. 30%

    Loop: the stupid things that adults do

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    Loop: The stupid things that adults do The Thanet Loop is a bus route that circumnavigates Margate, Ramsgate and Broadstairs. This continuous service acts as a conveyer to the community, delivering children to school, patients to the hospital, commuters to their places of work and shoppers to town centres. In its own modest way ‘The Loop’ circulates life through Thanet, creating a pulse or a perpetual rhythm. The project ‘Loop: the stupid things that adults do’ explores the idea of a circular journey with the intention of investigating repetition. In his book ‘Rhythmanalyisis,’ philosopher Henri Lefebvre identifies two types of repetition, circular and linear. Circular repetition develops from the cosmos and occurs naturally in days, seasons, tides and phases of the moon. While linear repetition is a social construct, imposed by structure, which can result in monotonous behaviour, such as daily commutes or routine visits to the dentist. These two patterns of repetition consistently and repeatedly effect and interfere with each other, creating patterns and sequences that are part of daily life. These cycles overlap and infuse, as individual patterns of behaviour briefly entwine within the enclosed space of the bus. Furthermore, in bringing together separate individuals or trajectories there cannot be any absolute repetition, as there will always be an interjection of difference or unforeseen circumstances. The aim of each image is to record the duration of a full circuit of ‘The Loop’ in one single flat image. Repeating exactly the same journey on different days and at slightly varying times, the work explores the differentiation that can occur in replication. All the individual journeys, commutes and routines are collocated and re-presented into a distinct image for each loop. The resulting images have two titles; the first is a code that relates to the time of the trip, marking it out through a classification process. The second is produced from the conversations overheard on each particular journey. Photography as a medium is fatally intersected by temporality; the camera reduces everything to a still frame, objectifying it through a process. Time and its complex rhythms are simplified, to a state where they are traces of what has passed. Photographs as images are removed from the continuous pressures of time, allowing the subject to be contemplated, examined and considered at leisure. In order to record the whole journey within a single image, the photographs are taken using a purpose made pinhole camera. Slowly absorbing the changes before the lens, each image becomes a representation of the journey and what passed before the camera on that specific excursion. Each unique image is characterised by the people using the bus, who punctuate the journey by choosing where the bus stops. These interruptions leave an imprint within the photographs produced. However, the main emphasis of each image is the light absorbed by the film, capturing the mood or atmosphere of that day. Thanet is renowned for the unique quality of light, which has attracted artists such as J.M.W. Turner to the area. This variation and luminosity of light comes into focus through the series and creates a unique collection of images

    Is the even distribution of insecticide-treated cattle essential for tsetse control? Modelling the impact of baits in heterogeneous environments

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    Background: Eliminating Rhodesian sleeping sickness, the zoonotic form of Human African Trypanosomiasis, can be achieved only through interventions against the vectors, species of tsetse (Glossina). The use of insecticide-treated cattle is the most cost-effective method of controlling tsetse but its impact might be compromised by the patchy distribution of livestock. A deterministic simulation model was used to analyse the effects of spatial heterogeneities in habitat and baits (insecticide-treated cattle and targets) on the distribution and abundance of tsetse. Methodology/Principal Findings: The simulated area comprised an operational block extending 32 km from an area of good habitat from which tsetse might invade. Within the operational block, habitat comprised good areas mixed with poor ones where survival probabilities and population densities were lower. In good habitat, the natural daily mortalities of adults averaged 6.14% for males and 3.07% for females; the population grew 8.46in a year following a 90% reduction in densities of adults and pupae, but expired when the population density of males was reduced to <0.1/km2; daily movement of adults averaged 249 m for males and 367 m for females. Baits were placed throughout the operational area, or patchily to simulate uneven distributions of cattle and targets. Gaps of 2–3 km between baits were inconsequential provided the average imposed mortality per km2 across the entire operational area was maintained. Leaving gaps 5–7 km wide inside an area where baits killed 10% per day delayed effective control by 4–11 years. Corrective measures that put a few baits within the gaps were more effective than deploying extra baits on the edges. Conclusions/Significance: The uneven distribution of cattle within settled areas is unlikely to compromise the impact of insecticide-treated cattle on tsetse. However, where areas of >3 km wide are cattle-free then insecticide-treated targets should be deployed to compensate for the lack of cattle

    Is there a nonlinear relationship between public investment and private investment? Evidence from 21 Organization for Economic Cooperation and Development countries

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    This paper studies the relationship between public investment and private investment in a sample of 21 Organization for Economic Cooperation and Development (OECD) countries between 2000 and 2019. Using panel data nonlinear threshold regression models, the empirical results show that there exist threshold levels for the share of public investment in private investment, the real Gross Domestic Product (GDP) growth rate and the real interest rate that affect the relationship between public and private investment. All estimates support a crowding-in effect of public investment on private investment. In terms of policy prescriptions, by increasing public investment, OECD governments can expect positive spillovers to private investment.info:eu-repo/semantics/publishedVersio

    Is policy leading to improved sustainability at the local urban scale?

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    In New Zealand, urban growth strategies and environmental policies at national and regional levels are influencing urban transformations at the local scale. Intensified residential and mixed use developments are emerging at growth nodes as outcomes of the Auckland Regional Growth Strategy 2050. The New Zealand Urban Design Protocol identified significant influences from government legislation, strategies and policies on urban design and the built forms at local level. The national walking and cycling strategy indicates that supportive local-scale layout and design in both existing and new developments could significantly influence travel behaviour. One of the six goals of the National Energy Efficiency and Conservation Strategy is to reduce local environmental effects of energy production and use. The Urban Form Design and Development (UFDD) work, part of the 'Auckland Sustainable Cities Programme' under the NZ Sustainable Development Programme of Action (NZSDPOA), focussed on policy mechanisms to drive sustainable urban form at the local scale in the Auckland Region. Using a case study-based approach, this paper investigates how national and regional policies influence the environmental sustainability of emerging local residential forms at this scale, especially in the Auckland Region. Three selected case studies are examined in terms of: applied urban design principles; design characteristics including street patterns, subdivision layouts and open space provisions; density of development; potential and actual renewable energy use and available transport options. A comparison of the New Zealand approach to sustainable urban forms with an international zero energy residential development is made. Results indicate the policies could influence emerging local-scale urban forms in varied manners generating significantly different contributions to environmental sustainability

    Combined chips for atom-optics

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    We present experiments with Bose-Einstein condensates on a combined atom chip. The combined structure consists of a large-scale "carrier chip" and smaller "atom-optics chips", containing micron-sized elements. This allows us to work with condensates very close to chip surfaces without suffering from fragmentation or losses due to thermally driven spin flips. Precise three-dimensional positioning and transport with constant trap frequencies are described. Bose-Einstein condensates were manipulated with submicron accuracy above atom-optics chips. As an application of atom chips, a direction sensitive magnetic field microscope is demonstrated.Comment: 9 pages, 9 figure

    Development of on-line FTIR spectroscopy for siloxane detection in biogas to enhance carbon contactor management

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    Activated carbon filters are used to limit engine damage by siloxanes when biogas is utilised to provide electricity. However, carbon filter siloxane removal performance is poorly understood as until recently, it had not been possible to measure siloxanes on-line. In this study, on-line Fourier Transform Infrared (FTIR) spectroscopy was developed to measure siloxane concentration in real biogas both upstream (86.1–157.5 mg m−3) and downstream (2.2–4.3 mg m−3) of activated carbon filters. The FTIR provided reasonable precision upstream of the carbon vessel with a root mean square error of 10% using partial least squares analysis. However, positive interference from volatile organic carbons was observed in downstream gas measurements limiting precision at the outlet to an RMSE of 1.5 mg m−3 (47.8%). Importantly, a limit of detection of 3.2 mg m−3 was identified which is below the recommended siloxane limit and evidences the applicability of on-line FTIR for this application

    I feel wealthy: a major determinant of Portuguese households’ indebtedness?

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    This paper examines the response of household debt to households’ perception of house prices using data from the first wave of the Household Finance and Consumption Survey. Whereas the literature has hitherto emphasized the effects of housing wealth on consumption, this study concentrates on the effects on debt accumulation—distinguishing mortgage debt from non-mortgage debt and inspecting over-indebtedness. Different measures of housing wealth are considered, controlling for tenure years. The findings reveal that the effects of housing wealth differ by type of loans and with the measure of housing wealth. Over-indebtedness is driven by the same factors that determine mortgage debt, suggesting a strong association between having outstanding liabilities from the primary residence and the risk of entering into default. Further estimations by different income and wealth classes revealed dissimilar housing wealth effects, with non-mortgage debt tending to rise among lower-income households and over-indebtedness tending to be larger among the wealthier.info:eu-repo/semantics/acceptedVersio

    Europe at the crossroad of the Covid-19 crisis: Integrated macroeconomic policy solutions for an asymmetric area

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    The economic crisis triggered by the COVID–19 pandemics raised once again doubts about the eurozone's ability to deal with common serious economic problems. The effects of the 2008 – 2009’s economic and financial crisis have not been completely exhausted, and a new crisis of yet unknown proportions emerged, bringing with it the traditional divergences between a common and integrated approach to problems and a country-based approach conditioned by Euro Area restrictive and asymmetric macroeconomic rules. This chapter aims at contributing to a paradigm shift in the governance of the eurozone towards a less dominant tendency for ruling according to the interests of the most powerful economies, namely Germany, and to a more comprehensive and integrated approach of the eurozone dissimilar dynamics and asymmetries, including the case of small economies like Portugal. Two dimensions of this need for a new paradigm of eurozone governance are considered. Firstly, the need for a change in the economic policy concerning the crisis recovery, from a supply-push to a demand-pull orientation, supported on a fiscal and monetary policy mix, integrated in a comprehensive macroeconomic approach. It is important to recognize the role of the ECB since the 2008 – 2009’s crisis and in the current context but also the need for a more active intervention of fiscal policy, both converging towards a growth-oriented policy. Secondly, the need for a shift in external relations towards a more global integration-oriented policy, with the Eurozone positioning itself as an alternative to the current polarization between the United States and China. Our conclusions point to the need to i) give priority to growth and employment; ii) promote long-term economic sustainability based on integrated macroeconomic policies, the reduction of income concentration and the reconstitution of strong middle classes; iii) reorientate international relations into a perspective of cooperation; iv) reinforce regulation and global governance; and v) eliminate exceptional situations, such as offshores, tax havens and other forms of economic controls escape.info:eu-repo/semantics/acceptedVersio
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