5,429 research outputs found
Ecotoxicity and fungal deterioration of recycled polypropylene/wood composites: Effect of wood content and coupling
No full textPolypropylene (PP)/wood composites were produced by homogenization in a twin-screw extruder and injection molding of tensile bars. Their mechanical properties were determined before and after exposure to biological treatment, and the effect of the treatment was assessed by various ways including visual inspection and the measurement of weight loss. The ecotoxicity of the materials was also evaluated by using the bioluminescent bacteria Vibrio fischeri. The results proved that wood facilitates biodeterioration (colonization) under the conditions used. The coupling agents do not have inhibitory effect, but seems to stimulate fungal growth (biodeterioration) at large loads of wood flour. PP/wood composites can be considered quite durable, but the influence of wood content on environmental resistance must be taken into account for materials intended for applications requiring long-term outdoor exposure as the time of exposure to microbial colonization increases. Direct ecotoxic effect on aquatic ecosystems cannot be expected from PP/wood composites
Mechanical modelling of wood microstructure, an engineering approach
No full textThe macroscopic elastic behaviour of wood derives from the mechanical performance of the cells which form its microstructure. Numerical finite element models are presented which relate the elastic properties of the wood continuum to local cell characteristics such as cell size, wall thickness, moisture content and microfibril angle. Preliminary results show good agreement with observed values
Settlement, growth and reproduction in the deep-sea wood-boring bivalve mollusc Xylophaga depalmai.
No full textExperimental panels of spruce and oak deployed at 3 and 6 mo intervals over a period
of several years at ca. 500 m depth in the NE Tongue of the Ocean, Bahamas, were rapidly colonised
by the wood-boring bivalve Xylophaga depalmai Turner, 2002. Colonisation of the wood occurred
year-round but there was evidence that it was more intense in the summer months. The population
structure of X. depalmai was the same for spruce and oak, although there was evidence that the
female population structure in each wood type differs significantly from the male population
structure. X. depalmai grew at a mean rate of ca. 0.03 mm d–1. Gametogenesis was initiated in
individuals of X. depalmai in all deployments and was active by Day 59. Egg size was ca. 40 ?m
diameter and fecundity was high. Once initiated, gametogenesis was quasi-continuous and gamete
density suggested that spawning was periodic. There was no difference in gametogenesis in individuals
from different wood types
President Cole Introduces Commencement Speaker Dr. C.M. Dannelly
No full textThe 60th annual commencement exercises were held May 31, 1943 at Jacksonville State Teachers College in the new Student Activity Building. Dr. C.M. Dannelly delivered the address to the graduating classes of the college and high school. Shown President Houston Cole introduces baccalaureate speaker Dr. C. M. Dannelly, superintendent of the Montgomery Public Schools. Seated left to right are C.M. Dannelly, JSTC Dean C.R. Wood, and Jacksonville Methodist Church pastor Charles Ferrell.https://digitalcommons.jsu.edu/lib-ac-histimg/3299/thumbnail.jp
Bone-eating worms and wood-eating bivalves: characterising the ecology of deep-sea organic falls from multiple ocean basins
No full textLarge organic inputs to the deep seafloor such as the remains of whales or pieces of wood are termed ‘organic falls’. Despite over 30 years of research on these interesting deep-sea habitats, we still have only a basic understanding of their taxonomic composition and for some ocean basins, no natural or experimental studies have ever been conducted. The degree of connectivity between these isolated habitats, as well as how quickly organic matter is remineralised by specialist organic-fall fauna (e.g bone-eating Osedax worms and wood-eating Xylophaga molluscs) is poorly known.In this thesis, I report the discovery of the first Antarctic whale fall and the diverse assemblage of fauna encrusting it (Chapter 2). The microdistribution of fauna on the whale bones provided evidence for the ‘oil-gradient’ hypothesis that more lipid-rich bones support a greater abundance of sulfophilic bacterial mats, which are also correlated with the abundance of grazing fauna. The abundance of Osedax species on bones however, showed a negative correlation with the bacterial-mat cover, and hence the greatest abundance was on bones predicted to have the lowest lipid content. The Osedax species discovered were investigated in detail (Chapter 3) and revealed two new species and a third previously-known species; Osedax rogersi sp. nov., Osedax crouchi sp. nov. (described in this thesis and associated paper) and Osedax antarcticus. The new species, O. crouchi as well as another new species, Osedax nordenskioeldi sp. nov. (also described in this thesis and associated paper) and Osedax antarcticus were also found on implanted whale bones off Smith Island in the Bransfield Strait. These two localities are approximately 1800 km apart demonstrating the remarkable dispersal capability of species within this genus.As well as the Antarctic study, I report on wood and bone-colonisation experiments on the Southwest Indian Ridge at two seamounts. A large number of species were found colonising the deployments; 53 species at Coral Seamount and 38 species at Atlantis Bank seamount with only 11 species in common and several putative new species present. Apart from Xylophaginae and Idas bivalves, few organic-fall specialists were present, possibly as there were major differences between the two seamounts suggesting that there were barriers to dispersal (Chapter 4). The wood deployments from each seamount were investigated in further detail using X-ray micro-computed tomography to examine the nature of intact Xylophaga borings, the comparative abundances and population size structures of the species, their rates of growth and their consumption rates of wood (Chapter 5). Two more sets of samples from the Mid-Cayman Spreading Centre and the Tongue of the Ocean, Bahamas were scanned also. The wood at each deployment site was colonized by a different species of Xylophaga. This novel analysis has shown that an individual Xylophaga can bore between 0.235 and 0.606 cm3 of wood per year depending on the species, emphasising the importance of the genus Xylophaga with regard to wood remineralisation in the deep sea and its role as an ecosystem engineer
Evaluation of the Pan-African Development Information System (PADIS): with particular reference to Zambia
No full textBased on research for C.M. Kangulu's PhD degree which was not financed by IDR
C.M. Wood over Polo Field
No full textPhoto shows airplane of aviator Clyde Murvin Wood (b. 1885?-1967) flying over the international polo tournament at Meadowbrook, Long Island, in June 1913. (Source: Flickr Commons project, 2009)Title and date from data provided by the Bain News Service on the negative.Forms part of: George Grantham Bain Collection (Library of Congress).General information about the Bain Collection is available at http://hdl.loc.gov/loc.pnp/pp.ggbai
Hirt
No full textWhen in the wood, Far far from thee, Thine image fair Followeth meEnglish words by C.M. Smith. Lyrics in English, German and Swedish. "Entered according to act of Congress, in the year 1874, by Lous Meyer, in the office of the Librarian of Congress, at Wash'n.
Acetic and formic acids emitted from wood samples and their effect on selected materials in museum environments
No full textThe concentrations of acetic acid and formic acid vapours emitted by a number of wood samples held in sealed environments were measured to assess differences between hardwood and softwood species. Three cases studies are reported where sodium formate, lead formate and acetate-based efflorescences were identified on glass, lead and calcareous artefacts held in heritage environments with elevated acetic acid and formic acid vapours. Simulated experiments were undertaken to assess the affect of formic acid vapour on limestone, egg shell, copper, lead and brass coupons and it was confirmed that porous limestone preferentially scavenged formic acid vapours from air
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