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Almudena Majano-Majano Mark Hughes Jose L. Fernandez-Cabo 《Wood Science and Technology》2012,46(1-3):5-21
The fracture toughness of thermally modified beech (Fagus sylvatica L) and ash (Fraxinus excelsior L) wood under Mode I loading was quantified using Compact Tension (CT) specimens, loaded under steady-state crack propagation conditions. The influence of three heat-treatment levels and three moisture contents, as well as two crack propagation systems (RL and TL) was studied. Complete load–displacement records were analysed, and the initial slope, k init, critical stress intensity factor, K Ic, and specific fracture energy, G f, evaluated. In the case of both species, thermal modification was found to be significantly affect the material behaviour; the more severe the thermal treatment, the lower the values of K Ic and G f, with less difference being observed between the most severe treatments. Moisture content was also found to influence fracture toughness, but had a much less significant effect than the heat treatment. 相似文献
104.
Hughes V Garcia-Sanchez A Smith S Mclean K Lainson A Nath M Stevenson K 《Veterinary microbiology》2012,158(1-2):153-162
Mycobacterium avium subspecies paratuberculosis (M. a. paratuberculosis) is a pathogen of ruminants, causing paratuberculosis (characterized by severe emaciation). The disease is endemic in many countries including the UK and places a severe economic burden on the global livestock industry. Two types of M. a. paratuberculosis can be classified by pulsed-field electrophoresis (I/III and II), which are phenotypically distinct and appear to have different host preferences. Proteomes of Type I and Type II M. a. paratuberculosis were analyzed by 2-D gel electrophoresis to determine if any significant differences existed between the subtypes. Seven different strains of Type I and 18 strains of Type II were analyzed and compared to detect type-specific differences. These 'type-specific' differences existed regardless of growth phase and were also exhibited in cells isolated directly from pathogenic lesions. Twenty-three spots predominated on the Type I profile, from which 17 proteins were identified. Twenty-one spots predominated on the Type II profile, from which 16 proteins were identified. None of the proteins identified as differentially represented on the profiles of Type I or Type II corresponded to open reading frames of the defining genomic regions as previously described for the Type I (sheep) and Type II (cattle). Sequence polymorphisms existing in Type I and II strains were identified in some open reading frames or regulatory regions of genes that correspond to proteins expressed in a type-specific fashion. The consequence of these is discussed in relation to protein expression and their impact on the type phenotype is discussed. 相似文献
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Anna Dupleix Domingos De Sousa Meneses Mark Hughes Rémy Marchal 《Wood Science and Technology》2013,47(6):1231-1241
There is a lack of quantitative data on the penetration depth and the amount of energy absorbed by green wood under infrared (IR) radiation. This lack of knowledge is a potential barrier to the development of IR heating as an alternative to soaking as a means of warming logs prior to peeling in the manufacture of plywood. Experimental measurements of normal hemispherical spectral reflectance and transmittance over the range 550–5,500 cm?1 wavenumbers on four wood species, beech, birch, Douglas-fir and spruce have brought new knowledge on mid-infrared absorption properties of green wood and removed some uncertainties. For instance, it is not possible to deliver energy deeper than up to 0.3 mm below the wood surface because 70–90 % of all incident IR radiation on the wood surface is absorbed in this layer. Some wood features, such as surface quality, the presence of knots and of free water in wood (the latter two having a more significant effect) influence the amount of energy absorbed. These results illustrate that IR radiation can heat the surface layers, but then heat penetrates deeper into the inside layers of wood by conduction. 相似文献
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Rosaleen M. Hyde Timothy M. Lynch Carol K. Clark Donnie E. Slone Faith E. Hughes 《The Canadian veterinary journal. La revue veterinaire canadienne》2013,54(4):363-367
This study investigated the influence of perfusate volume on antimicrobial concentration in synovial fluid following intravenous regional limb perfusion (IVRLP) and assessed the efficacy of low volume IVRLP. The front limbs of 9 horses were randomly assigned to 1 of 3 volume groups: 10 mL (Group 1), 30 mL (Group 2), or 60 mL (Group 3). A tourniquet was applied distal to the carpus and the limbs were perfused with 500 mg genta-micin diluted to the assigned volume via a catheter placed in the lateral palmar digital vein at the level of the proximal sesamoid bones. Synovial fluid samples were collected from the metacarpophalangeal joint at 30 minutes, followed by removal of the tourniquet. Gentamicin concentration in synovial fluid was detected using a fluorescence polarization immunoassay. There were no statistically significant differences among gentamicin concentrations in synovial fluid among perfusate volume groups. Mean gentamicin concentration in Group 1 (125.9 μg/mL) was higher than Group 2 (82.7 μg/mL) and Group 3 (56.1 μg/mL). 相似文献
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Extract Sir:During the last three years we have become increasingly involved with the tuberculin testing of deer. This experience has convinced us of the importance of carefully applying and reading the test. A recent case has highlighted this. 相似文献
109.
P.L. Hughes 《New Zealand veterinary journal》2013,61(12):201-203
Extract Animals are protected from infectious diseases by non-specific and specific mechanisms. The non-specific defenses include a number of physical host factors, such as intact epithelium, mucus secretions and cilia of the respiratory system, which act to prevent or impede infection. Occasionally, either because of trauma or adverse effects of the environment on such barriers or because of the invasiveness of a particular pathogen, an infection becomes established and disease develops; host resistance then becomes mainly a function of specific, acquired immunity. 相似文献
110.
Papillomavirus was identified in two fibromatous dermal nodules which were representative of those present in the caudal fold skin of the tail in 25 of 145 beef cattle tuberculin tested 3 months earlier. Bovine warts were endemic on the property and it is hypothesised that the papilloma virus was introduced intradermally by a virus-contaminated tuberculin syringe. At palpation, the well-circumscribed hard nodular lesions were atypical of the diffuse caudal fold swelling usually present in reactions to tuberculin. Provided tuberculin testing officers are aware of the risk of fibroma and papilloma induction by transmission of papillomavirus, and they are careful to prevent equipment coming into contact with warts at time of inoculation, this source of inaccuracv mav be avoided. 相似文献