4,815 research outputs found
Big Talk, 6/26/2014
No full textAl Brewer interviews author Sandy Martin about his new book, Paddling Against the Tide: The Story of Lincoln Canoe, an Entrepreneurial Saga.https://digitalcommons.usm.maine.edu/wmpg_bigtalk/1118/thumbnail.jp
Low faunal diversity on Maltese sandy beaches : fact or artefact?
No full textEight sandy beaches on Malta and two on Gozo were sampled for macrofauna to test the hypothesis that Maltese beaches have
an intrinsically low diversity. Stations distributed in the supralittoral (dry zone), mediolittoral (wet zone) and upper infralittoral
(submerged zone to 1m water depth) were sampled by sieving core samples and standardised searching during daytime, and pitfall
trapping and standardised sweeping of the water column using a hand-net at night, as appropriate. Physical parameters of the
sediment were measured and human occupancy of the beaches was estimated.
From the supralittoral and mediolittoral, 39 species represented by 1584 individuals were collected by the combined techniques of
pitfall trapping, sieving and standard searching. For Ramla beach, which had the highest diversity, 267 individuals representing 25
infaunal species were collected by sieving from a combined volume of 1.175m3 of sand, and 149 individuals representing 28
epifaunal species were collected by standardised searching from a combined area of 700m2 of sand during two winter and two
summer sampling sessions between 1992 and 1993. For nine other beaches sampled during the summer of 2000, only six
macrofaunal species were collected from core samples, with overall population densities ranging from 4.13 to 45.45 individualsm 2.
Only 92 individuals belonging to 12 species were collected by hand-net from the uppermost infralittoral of five beaches sampled
using this method during the summer of 2000. Taxa of gastropods, bivalves, decapods, mysids and staphylinid beetles generally
abundant on Mediterranean sandy beaches, were entirely absent from the beaches sampled.
Few correlations that could explain the impoverishment of Maltese sandy beaches were found between physical parameters and
faunal abundances, and other factors such as inadequate sampling effort, human disturbance and marine pollution were also
excluded; however, seasonally biased sampling may partly explain the results obtained. One factor that may explain why certain
species are missing could be lack of recruitment, due to Malta’s geographical isolation from the European and African mainlands.
2003 Elsevier Ltd. All rights reserved.peer-reviewe
The influence of coastal upwelling on the biodiversity of sandy beaches in South Africa
No full textSandy beaches are often highly allochthonous, depending on external subsidies of carbon and nutrients. Despite this, sandy beach macrofaunal assemblages have received little attention regarding their response to enhanced primary productivity generated from coastal upwelling. This thesis investigates the influence of upwelling on macrofaunal assemblages over a variety of spatial and temporal scales. Spatially, four regions were examined across two biogeographic provinces to remove temperature as a confounding factor, and limit biogeography-specific effects. A nested hierarchical design enabled both large and small scales to be examined and generalities about upwelling effects across multiple areas to be considered. Sampling was conducted in two seasons, and over two years, to test the persistence of any effects. Biogeography and region had the strongest influences on macrofaunal biodiversity. Upwelling influenced macrofaunal assemblages in every region when analyses were conducted at the species level. However, the particular effect, positive or negative, differed among regions depending on local factors, and between the response variables, abundance and biomass. Coarser scales of taxonomy, feeding guild and developmental mode were investigated; however, the influence of upwelling generally became weaker and more varied, and occasionally disappeared. Seasonality was greater on the South Coast but was still important in some analyses on the West Coast. At the small-scale, variation within-beaches was lower than between beaches, assemblage structure remained stable over time, and consistent zonation was not present. The influence of temperature on filtration rate and oxygen consumption of Donax serra was investigated to test a driving mechanism for assemblage responses to upwelling. Feeding ability was significantly reduced at colder temperatures indicating an important factor which may be involved in determining assemblage structure. These results suggest that alterations to upwelling regimes predicted under climate change scenarios will impact sandy beach macrofauna, however the specific outcome will depend on multiple contextual factors
Growth and yield responses in maize to split and delayed fertilizer applications on sandy soils under high rainfall regimes
No full textThe yield of maize (Zea mays L.) on sandy soils with high rainfall regimes is generally low due to poor nutrient use efficiency. Split and delayed basal fertilizer applications are possible strategies to improve the crop yield and reduce nutrient loss through leaching in sandy soils, but their effectiveness under high rainfall regimes to produce a maize growth response needs further investigation. The aim of the study was to determine the effect of fertilizer application methods on the growth, yield and agronomic characteristics of maize on a sandy soil with approximately 1,350 mm of rainfall during crop growth. Field experiments were conducted on Oxic Paleustults (Korat series) with a low cation exchange capacity (CEC) of 2–4 cmol kg–1. Three to four split applications of the fertilizer increased the grain yield from 2.7 to 3.3–4.5 Mg ha–1. There was a greater crop growth rate (CGR) and relative growth rate (RGR) with the split applications of fertilizer during 30–60 d after emergence (DAE). The highest agronomic efficiency (AE) resulted from a three-split application. However, application of fertilizer later than 45 DAE had only a low effective rate. Delaying the basal fertilizer application to 7–15 DAE increased the grain yield to 3.5–3.7 Mg ha–1, whereas a pre–planting application produced a yield of 2.7 Mg ha–1. Delaying the basal fertilizer application to 7–15 DAE improved the CGR, RGR and AE. These results indicated that fertilizer applications to minimize nutrient loss increased the growth and nutrient use efficiency of maize on sandy soil in a high rainfall regime
Drone images of sandy beaches and anthropogenic litter along the Saudi Arabian Red Sea
No full textWe provide the original drone images acquired with a DJI Phantom 4 Professional (Pro) at a 10 m altitude, a camera gimbal at a nadir point and 70% side and front overlaps. The images were acquired in 5 beaches along the Saudi Arabian Red Sea coast. This is a subsample of the 44 beaches surveyed during an assessment of anthropogenic beach litter as described in Martin et al. 2021 "Anthropogenic litter density and composition data acquired flying commercial drones on sandy beaches along the Saudi Arabian Red Sea", Data in Brief
Non-discursive knowledge and the construction of identity. Potters, potting and performance at the bronze age tell of Százhalombatta, Hungary
No full textThis article explores the relationship between the making of things and the making of people at the Bronze Age tell at Százhalombatta, Hungary. Focusing on potters and potting, we explore how the performance of non-discursive knowledge was critical to the construction of social categories. Potters literally came into being as potters through repeated bodily enactment of potting skills. Potters also gained their identity in the social sphere through the connection between their potting performance and their audience. We trace degrees of skill in the ceramic record to reveal the material articulation of non-discursive knowledge and consider the ramifications of the differential acquisition of non-discursive knowledge for the expression of different kinds of potter's identities. The creation of potters as a social category was essential to the ongoing creation of specific forms of material culture. We examine the implications of altered potters' performances and the role of non-discursive knowledge in the construction of social models of the Bronze Ag
Guy Martin: whole life cost
No full textThis exhibition catalogue was published on the occasion of the exhibition 'Guy Martin: whole life cost', which toured during 2006 and 2007 to venues including the Crafts Study Centre, Farnham, and Bluecoat Display Centre, Liverpool.\ud
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This Devon Guild of Craftsmen Touring exhibition is a survey of the current work of seminal furniture maker Guy Martin. A key member of the influential furniture institution, Parnham College, and Member of The Devon Guild of Craftsmen, Guy was short listed for the Jerwood Applied Arts Prize in 1999. Now making work that spans furniture, interior design and architecture, the exhibition focuses on issues of sustainability, ethical production and a sense of locality. Whole Life Cost is a calculation not only of the one-off cost of manufacture and construction, but also the future cost to ourselves and our planet, calculating social and cultural value as well as economic. \ud
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The catalogue includes two essays, one by Professor Simon Olding and one by artist and writer Sandy Brown
Structural analysis and parametric study ballasted track in sandy regions
No full textThe sand intrusion in railway tracks in sandy regions can significantly change the mechanical behaviour of tracks and thus threaten the safety of train operation. This paper presents substantial field tests on both sandy and clean railway tracks to study the effect of sand intrusion on the longitudinal resistance of ballast bed and the vibration behaviour of track structures. After that, a 3D multi-scale the discrete element model is developed to study the micro-contact between ballast particles and the vibration behaviour of sandy tracks during train passing in detail. Also, the effect of train speeds and axle loads on the mechanical behaviour of sandy tracks is discussed. The results show that the sand intrusion increases the vibration acceleration amplitude of rail and sleeper by 11.3% and 50.3%, while ballast bed decreases by 44.9%. Besides, the sand intrusion significantly changes the energy distribution in the track, wherein the frequencies of the highest energy of rail and sleeper are increased while that of the ballast bed is decreased. The parametric study shows the high train speed can cause the increase in overall acceleration of the ballast bed and high axle load can cause an increase in the micro-contact forces between ballast particles, diffusion angle of the contact force chain, displacements of ballast particles, acceleration of ballast particles, and sleeper displacements.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Mechanics and Physics of Structure
Crushed rock and clay amelioration of a nutrient decifient, sandy soil of Maputaland
No full textBibliography: leaves 57-62.Various studies have suggested the possibility that food derived through subsistence agriculture in the Mseleni region of Maputaland contributes to malnutrition within the local community, particularfy within the high proportion of the population which suffers from a severe, disabling form of osteoarthritis. This study was conducted to determine if the application of local crushed rock or black clay to these nutrient deficient, sandy soils would increase available nutrient concentrations and improve the growth of plants in the ameliorated soil
The effectiveness of commercially available wetting agents for combating on-site soil water repellency in sandy soil
No full textSoil hydrophobicity reported to be a worldwide problem throughout the world and Australia affecting diverse soil types particularly soil with high sand content. Soil hydrophobicity affect surface and subsurface hydrology, enhance overland flow and soil erosion, reduce seed germination and crop growth, cause preferential flow and associated leaching of nutrients and agrochemicals. The cause of soil water repellency is believed to be organic coating of the soils particles result from breakdown of organic substances such as; plant roots, fungal or microbial by-products. The most common method of managing soil water repellency in urban areas is application of wetting agents most of which are surfactant based. A trial was conducted at Murdoch University to test the efficacy of three leading locally available commercial wetting agent products and their effect on three commercially available pre-mixed landscape soils. Results from capillary rise, WDPT and double ring infiltrometer tests suggest that; application of selected wetting agents not only did not result in enduring improvement in soil wettability, but also in some cases appear to enhance soil water repellency. These observations lead to the hypothesis that; surfactant molecules in the wetting agents bond to soil particles in the same way as organic hydrophobic materials that coat the soil grains. To substantiate the results, further investigation required to understand the mechanism by which wetting agent molecules interact with soil particles
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