| 1. |
- Nijhuis, H.H., et al.
(författare)
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Research needs and opportunities in the dry conservation of fruits and vegetables
- 1996
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Ingår i: Drying Technology. - 0737-3937 .- 1532-2300. ; 14:6, s. 1429-1457
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Tidskriftsartikel (refereegranskat)abstract
- The consumer demand for healthy convenience meals with 'near fresh' properties challenges researchers and industry to develop new or improved conservation procedures for food products. However, this recent food trend towards fresh image on one side and convenience on the other side often conflict. In most cases the fresh quality is negatively affected by the processing procedure. Therefore nowadays efforts are focussed on extending the shelf life of fresh products. However, sophisticated energy demanding facilities are required for storage and transporation, whereas the use of ecologically unsound cooling agents is a major drawback. The development of a dehydration process on the basis of electromagnetic energy (EME) may bring about a major breakthrough with respect to the retention of product quality and improved rehydration characteristics. Due to the tenfold weight reduction established in the dehydration process transport and storage costs are minimised thus reducing energy consumption. In comparison with fresh and frozen products minimal storage facilities are required. The strategy of a consortium of five EC-research centres and two dutch drying companies is to combine and fine tune hot air drying (low processing costs) and EME-drying (quality retention) into a hybrid process, to compare the performance with conventional methods and to include packaging and storage effects. Optimisation of the rewettability is one of the major concerns since food materials with near fresh properties can only be obtained from dry material if rehydration characteristics are excellent. To establish such dried fruits and vegetables will be considered as blends of polymeric materials. Many quality deterioration mechanisms can be attributed to the mobility of the polymeric matrix and the diffusion of water. Properties thus depend on the composition, the physical properties of the polymers (mobility) and the overall structure of the dried material. This approach in which process conditions in the dehydration of food materials are linked to a broad range of relevant macroscopic as well as microscopic data is highly innovative and will provide important scientific information. The process-quality relationships are a solid basis to optimize both existing and novel dehydration methods.
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| 2. |
- Akhmedov, Evgeny, et al.
(författare)
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Stability and leptogenesis in the left-right symmetric seesaw mechanism
- 2007
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Ingår i: Journal of High Energy Physics (JHEP). - : Springer Science and Business Media LLC. - 1126-6708 .- 1029-8479. ; 4, s. 022-1-022-25
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Tidskriftsartikel (refereegranskat)abstract
- We analyze the left-right symmetric type I+II seesaw mechanism, where an eight-fold degeneracy among the mass matrices of heavy right-handed neutrinos M-R is known to exist. Using the stability property of the solutions and their ability to lead to successful baryogenesis via leptogenesis as additional criteria, we discriminate among these eight solutions and partially lift their eight-fold degeneracy. In particular, we find that viable leptogenesis is generically possible for four out of the eight solutions.
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| 3. |
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| 4. |
- Balogh, Istvan, et al.
(författare)
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Increasing the Degree of Automation in a Production System: Consequences for the physical workload
- 2006
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 1872-8219 .- 0169-8141. ; 36:4, s. 353 - 365
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Tidskriftsartikel (refereegranskat)abstract
- In spite of the continuous development of production systems work-related musculoskeletal disorders is still a large problem. One reason might be the difficulties in quantifying the ergonomic effects of interventions. In this paper ergonomic consequences of technical and organisational changes were quantified in a plant for producing slats for parquet flooring. Muscle activity, work postures and movements were assessed for neck/shoulders and upper limb by direct technical measurements at three generations of production lines. The physical workload for 31 operators at the manual, semi-automated and automated line was derived based on all existing work tasks. The work was characterised by moderate muscular loads, the 50th percentiles being 1.2-3.8%MVE for the neck/shoulder muscles, high repetitiveness and constant movements of the hands and a high prevalence of neck/shoulder disorders. There were statistically significant differences considering exposure levels between the work tasks within each line as well as between the lines. The semi-automated line implied reduced muscular load for all muscles registered but more constrained work postures. The automated line, on the other hand, required higher skills, offered less constrained postures, lower loads and repetitiveness for the hands as well as frequent changes between different physical load levels. Relevance to industry: When designing or redesigning production systems, technical solutions are often used to obtain 'beneficial' ergonomic conditions, implying a strive for low physical workloads. However, there is a risk that this might lead to more constrained physical activities. Possibilities for job enlargement must be thoroughly utilised. © 2006 Elsevier B.V. All rights reserved.
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| 5. |
- Bansch, Peter, et al.
(författare)
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Effect of charge on microvascular permeability in early experimental sepsis in the rat.
- 2011
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Ingår i: Microvascular Research. - : Elsevier BV. - 1095-9319 .- 0026-2862. ; 82, s. 339-345
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Tidskriftsartikel (refereegranskat)abstract
- A key feature of sepsis is hypovolemia due to increased microvascular permeability. It has been suggested that the negative charge of albumin and of the endothelial glycocalyx is important for maintenance of the normally low permeability for albumin. Here we tested the hypothesis that charge effects contribute to the increased permeability in sepsis. Transcapillary escape rate (TER) and initial distribution volume for (125)I-labeled bovine serum albumin (BSA, isoelectric point pH 4.6) and for (131)I-labeled charge modified BSA (cBSA, average isoelectric point, pH 7.1) was measured 3h after sepsis was induced by cecal ligation and incision (CLI) (n=11) and in control animals (n=12). The importance of charge for permeability in sepsis was estimated by comparing the ratio between TER for cBSA and TER for BSA during control conditions to that after CLI. Plasma concentration of the glycocalyx component glycosaminoglycans (GAGs) was measured in separate control and CLI animals. The initial distribution volume for BSA and cBSA in control animals was 38±3ml/kg and 47±4mL/kg and decreased by 17% and 19%, respectively, following CLI. TER for BSA increased from 16.7±4.1% in the controls to 20.1±1.9% following CLI. Corresponding values for cBSA were 26.7±5.6% and 29.8±3.5%, respectively. The ratio between TER for cBSA and TER for BSA was 1.62±0.1 in the control group and 1.49±0.1 following CLI (p<0.05). Plasma GAG concentrations were higher in CLI animals than in the control group. We conclude that CLI induce hypovolemia secondary to increased microvascular permeability. Negative charge contributes to the normally low permeability of albumin and the importance of charge is decreased in early experimental sepsis. The observed charge effects are associated with CLI-induced breakdown of the glycocalyx.
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| 6. |
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| 7. |
- Bernstone, Christian, et al.
(författare)
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DC resistivity mapping of internal landfill structures: two pre-excavation surveys.
- 2000
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Ingår i: Environmental Geology. - : Springer Science and Business Media LLC. - 0943-0105 .- 1432-0495. ; 39:3-4, s. 360-371
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Tidskriftsartikel (refereegranskat)abstract
- Geophysical investigations using 2-D DC resistivity were carried out on old parts of two similar landfills, with waste of different ages. The data sets, which included high data density in both vertical and horizontal directions, were interpreted with 2-D smoothness constrained inversion. The landfills were excavated after the surveying. The objective was to test the capability of the resistivity method as a pre-characterization technique. The objectives were only partially fulfilled. First, the moisture content was the parameter that appeared to exert the dominant control over the resistivity distribution of the landfill. The most important potential information that can be recovered is, therefore, an indication of the waste piles hydraulics. Second, it was neither possible to estimate the amount of recoverable soils, nor to correlate the type of waste with the resistivity models. However, discrete anomalies were identified, and if specific materials are searched for, the resistivity models indicate possible places to search.
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| 8. |
- Bi, Zhaoxia, et al.
(författare)
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Self-assembled InN quantum dots on side facets of GaN nanowires
- 2018
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 123:16
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Tidskriftsartikel (refereegranskat)abstract
- Self-assembled, atomic diffusion controlled growth of InN quantum dots was realized on the side facets of dislocation-free and c-oriented GaN nanowires having a hexagonal cross-section. The nanowires were synthesized by selective area metal organic vapor phase epitaxy. A 3 Å thick InN wetting layer was observed after growth, on top of which the InN quantum dots formed, indicating self-assembly in the Stranski-Krastanow growth mode. We found that the InN quantum dots can be tuned to nucleate either preferentially at the edges between GaN nanowire side facets, or directly on the side facets by tuning the adatom migration by controlling the precursor supersaturation and growth temperature. Structural characterization by transmission electron microscopy and reciprocal space mapping show that the InN quantum dots are close to be fully relaxed (residual strain below 1%) and that the c-planes of the InN quantum dots are tilted with respect to the GaN core. The strain relaxes mainly by the formation of misfit dislocations, observed with a periodicity of 3.2 nm at the InN and GaN hetero-interface. The misfit dislocations introduce I1 type stacking faults (...ABABCBC...) in the InN quantum dots. Photoluminescence investigations of the InN quantum dots show that the emissions shift to higher energy with reduced quantum dot size, which we attribute to increased quantum confinement.
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| 9. |
- Bjurberg, Maria, et al.
(författare)
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Early changes in 2-deoxy-2-[18F]fluoro-D-glucose metabolism in squamous-cell carcinoma during chemotherapy in vivo and in vitro.
- 2009
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Ingår i: Cancer Biotherapy & Radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1557-8852 .- 1084-9785. ; 24:3, s. 327-332
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The aim of this study was to investigate early changes in uptake of 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) in vivo and in vitro in a squamous-cell carcinoma (SCC) cell line originating from a human head and neck SCC during cytotoxic therapy with respect to metabolism in tumor cells and in surrounding stromal tissue. MATERIALS AND METHODS: In 60 nude mice with xenografted SCC, 50 animals were treated with cisplatin. Early changes in the tumor FDG uptake following therapy were evaluated sequentially with phosphor imaging. Using this technique, areas with focal hypermetabolism were detected. The cells creating the focal hypermetabolism were then identified histopathologically on the corresponding sections. In addition, early FDG uptake versus the number of viable tumor cells was measured in vitro following cisplatin treatment. RESULTS: An early transient increase in FDG uptake in tumor cells was seen on day 1 in treated tumors, followed by a rapid decrease confirmed by subsequent tumor regression. This metabolic flare was present in all treated tumors but not in the controls. In vitro, an increase in FDG uptake per cell was observed. CONCLUSIONS: Our results provide new insights into the early metabolic changes in squamous-cell carcinomas subjected to cytotoxic therapy and thus contribute to the discussion on the feasibility of early predictive PET studies.
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| 10. |
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