| 1. |
- Attard, Thohmas. M., et al.
(författare)
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Supercritical extraction as an effective first-step in a maize stover biorefinery
- 2015
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 5:54, s. 43831-43838
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Tidskriftsartikel (refereegranskat)abstract
- Supercritical carbon dioxide (scCO2) has been investigated for the generation of valuable waxy compounds and as an added-value technology in a holistic maize stover biorefinery. ScCO2 extraction and fractionation was carried out prior to hydrolysis and fermentation of maize stover. Fractionation of the crude extracts by scCO2 resulted in wax extracts having different compositions and melting temperatures, enabling their utilisation in different applications. One such fraction demonstrated significant potential as a renewable defoaming agent in washing machine detergent formulations. Furthermore, scCO2 extraction has been shown to have a positive effect on the downstream processing of the maize stover. Fermentation of the scCO2 extracted maize stover hydrolysates exhibited a higher glucose consumption and greater potential growth for surfactant (in comparison with non-scCO2 treated stover) axnd ethanol production (a 40% increase in overall ethanol production after scCO2 pre-treatment). This work represents an important development in the extraction of high value components from low value wastes and demonstrates the benefits of using scCO2 extraction as a first-step in biomass processing, including enhancing downstream processing of the biomass for the production of 2nd generation biofuels as part of an integrated holistic biorefinery.
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| 2. |
- Bergman, Anders, et al.
(författare)
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Metrology for high voltage direct current
- 2010
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Ingår i: CPEM Digest (Conference on Precision Electromagnetic Measurements). - 9781424467952 ; , s. 669-670
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Konferensbidrag (refereegranskat)abstract
- HVDC energy transmission is crucial for a successful uptake of renewable energy sources in the grid. A research program is described, intended to provide metrology support for the needs of HVDC energy transmission. This program will provide improvements for the present HVDC metrology infrastructure: accurate measurement of HVDC, determination of losses in HVDC systems, on-site power quality measurements at HVDC substations, and DC metering. It is a combined effort of 7 European national metrology institutes, one university and one industrial partner. © 2010 IEEE.
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| 3. |
- Bradley, E. L., et al.
(författare)
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The BIOSAFEPAPER project for in vitro toxicity assessments : Preparation, detailed chemical characterisation and testing of extracts from paper and board samples
- 2008
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Ingår i: Food and Chemical Toxicology. - : Elsevier BV. - 0278-6915 .- 1873-6351. ; 46:7, s. 2498-2509
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Tidskriftsartikel (refereegranskat)abstract
- Nineteen food contact papers and boards and one non-food contact board were extracted following test protocols developed within European Union funded project BIOSAFEPAPER. The extraction media were either hot or cold water, 95% ethanol or Tenax, according to the end use of the sample. The extractable dry matter content of the samples varied from 1200 to 11,800 mg/kg (0.8-35.5 mg/dm2). According to GC-MS the main substances extracted into water were pulp-derived natural products such as fatty acids, resin acids, natural wood sterols and alkanols. Substances extracted into ethanol particularly, were diisopropylnaphthalenes, alkanes and phthalic acid esters. The non-food contact board showed the greatest number and highest concentrations of GC-MS detectable compounds. The extracts were subjected to a battery of in vitro toxicity tests measuring both acute and sublethal cytotoxicity and genotoxic effects. None of the water or Tenax extracts was positive in cytotoxicity or genotoxicity assays. The ethanol extract of the non-food contact board gave a positive response in the genotoxicity assays, and all four ethanol extracts gave positive response(s) in the cytotoxicity assays to some extent. These responses could not be pinpointed to any specific compound, although there appeared a correlation between the total amount of extractables and toxicity.
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| 4. |
- Honkalampi-Hämäläinen, U., et al.
(författare)
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Safety evaluation of food contact paper and board using chemical tests and in vitro bioassays : Role of known and unknown substances
- 2010
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Ingår i: Food Additives and Contaminants. - : Informa UK Limited. - 0265-203X .- 1464-5122. ; 27:3, s. 406-115
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Tidskriftsartikel (refereegranskat)abstract
- In vitro toxicological tests have been proposed as an approach to complement the chemical safety assessment of food contact materials, particularly those with a complex or unknown chemical composition such as paper and board. Among the concerns raised regarding the applicability of in vitro tests are the effects of interference of the extractables on the outcome of the cytotoxicity and genotoxicity tests applied and the role of known compounds present in chemically complex materials, such as paper and board, either as constituents or contaminants. To answer these questions, a series of experiments were performed to assess the role of natural substances (wood extracts, resin acids), some additives (diisopropylnaphthalene, phthalates, acrylamide, fluorescent whitening agents) and contaminants (2,4-diaminotoluene, benzo[a]pyrene) in the toxicological profile of paper and board. These substances were individually tested or used to spike actual paper and board extracts. The toxic concentrations of diisopropylnaphthalenes and phthalates were compared with those actually detected in paper and board extracts showing conspicuous toxicity. According to the results of the spiking experiments, the extracts did not affect the toxicity of tested chemicals nor was there any significant metabolic interference in the cases where two compounds were used in tests involving xenobiotic metabolism by the target cells. While the identified substances apparently have a role in the cytotoxicity of some of the project samples, their presence does not explain the total toxicological profile of the extracts. In conclusion, in vitro toxicological testing can have a role in the safety assessment of chemically complex materials in detecting potentially harmful activities not predictable by chemical analysis alone.
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| 5. |
- Banks, J., et al.
(författare)
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Assessment of Digital Image Correlation as a method of obtaining deformations of a structure under fluid load
- 2015
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Ingår i: Journal of Fluids and Structures. - : Academic Press. - 0889-9746 .- 1095-8622. ; 58, s. 173-187
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Tidskriftsartikel (refereegranskat)abstract
- Digital Image Correlation (DIC) is employed for the measurement of full-field deformation during fluid-structure interaction experiments in a wind tunnel. The methodology developed for the wind tunnel environment is quantitatively assessed. The static deformation error of the system is shown to be less than 0.8% when applied to a curved aerofoil specimen moved through known displacements using a micrometre. Enclosed camera fairings were shown to be required to minimise error due to wind induced camera vibration under aerodynamic loading. The methodology was demonstrated using a high performance curved foil, from a NACRA F20 sailing catamaran, tested within the University of Southampton RJ Mitchell, 3.5. mx2.4. m, wind tunnel. The aerodynamic forces induced in the wind tunnel are relatively small, compared with typical hydrodynamic loading, resulting in small deformations. The coupled deflection and blade twist is evaluated over the tip region (80-100% Span, measured from the root) for a range of wind speeds and angles of attack. Steady deformations at low angles of attack were shown to be well captured however unsteady deformations at higher angles of attack were observed as an increase in variability due to hardware limitations in the current DIC system. It is concluded that higher DIC sample rates are required to assess unsteady deformations in the future. The full field deformation data reveals limited blade twist for low angles of attack, below the stall angle. For larger angles, however, there is a tendency to reduce the effective angle of attack at the tip of the structure, combined with an unsteady structural response. This capability highlights the benefits of the presented methodology over fixed-point measurements as the three dimensional foil deflections can be assessed over a large tip region. In addition, the methodology demonstrates that very small deformations and twist angles can be resolved.
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| 6. |
- Powell, Lydia C., et al.
(författare)
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An investigation of Pseudomonas aeruginosa biofilm growth on novel nanocellulose fibre dressings
- 2016
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 137, s. 191-197
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Tidskriftsartikel (refereegranskat)abstract
- Nanocellulose from wood is a novel biomaterial, which is highly fibrillated at the nanoscale. This affords the material a number of advantages, including self-assembly, biodegradability and the ability to absorb and retain moisture, which highlights its potential usefulness in clinical wound-dressing applications. In these in vitro studies, the wound pathogen Pseudomonas aeruginosa PAO1 was used to assess the ability of two nanocellulose materials to impair bacterial growth (<48 h). The two nanocelluloses had a relatively small fraction of residual fibres (<4%) and thus a large fraction of nanofibrils (widths <20 nm). Scanning electron microscopy and confocal laser scanning microscopy imaging demonstrated impaired biofilm growth on the nanocellulose films and increased cell death when compared to a commercial control wound dressing, Aquacel®. Nanocellulose suspensions inhibited bacterial growth, whilst UV-vis spectrophotometry and laser profilometry also revealed the ability of nanocellulose to form smooth, translucent films. Atomic force microscopy studies of the surface properties of nanocellulose demonstrated that PAO1 exhibited markedly contrasting morphology when grown on the nanocellulose film surfaces compared to an Aquacel® control dressing (p < 0.05). This study highlights the potential utility of these biodegradable materials, from a renewable source, for wound dressing applications in the prevention and treatment of biofilm development.
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| 7. |
- Wright, David A., et al.
(författare)
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Surface coating aids survival of Serratia entomophila (Enterobacteriaceae) in granules for surface application
- 2017
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Ingår i: Biocontrol science and technology (Print). - : Informa UK Limited. - 0958-3157 .- 1360-0478. ; 27:12, s. 1383-1399
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Tidskriftsartikel (refereegranskat)abstract
- The nonspore-forming bacterium Serratia entomophila may be used to control the New Zealand grass grub (Costelytra giveni) but is sensitive to environmental stress and must be formulated to improve survival. Existing formulations require subsurface application limiting the area that can be treated. Formulations that allow delivery by broadcast methods are desirable to reduce application costs and increase the potential for aerial application to inaccessible areas. Two formulations were prepared for use in experiments examining the persistence and movement of inoculum through soil. When granules were applied to the soil surface, bacterial survival was negligible in uncoated core, but improved with increasing thickness of the coating. Both survival of bacteria and release into the soil were influenced by soil moisture content. Granules at <12% soil moisture showed high bacterial mortality and reduced delivery to the soil, while at 28% soil moisture most bacteria were released to the soil. There was a high level of survival of the applied bacteria within granules at 20% and 28% soil moisture. The formulations maintained viability of S. entomophila in granules stored under ambient conditions for more than 6 months. In laboratory and field tests, the application of granules caused disease in the target grass grub larvae, whether application was applied to the surface or subsurface. In field trials, broadcast applied granules could produce equivalent disease to thin-coat granules drilled into the soil, but these levels of disease were associated with the occurrence of precipitation shortly after application.
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