| 1. |
- Granhall, Ulf, et al.
(författare)
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Bacterial community diversity in paper mills processing recycled paper
- 2010
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Ingår i: Journal of Industrial Microbiology & Biotechnology. - : Oxford University Press (OUP). - 1367-5435 .- 1476-5535. ; 37:10, s. 1061-1069
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Tidskriftsartikel (refereegranskat)abstract
- Paper mills processing recycled paper suffer from biofouling causing roblems both in the mill and final product. The total bacterial ommunity composition and identification of specific taxa in the process ater and biofilms at the stock preparation and paper machine areas in a ill with recycled paper pulp was described by using a DNA-based pproach. Process water in a similar mill was also analyzed to nvestigate if general trends can be found between mills and over time. acterial community profiles, analyzed by terminal-restriction fragment ength polymorphism (T-RFLP), in process water showed that the dominant eaks in the profiles were similar between the two mills, although the verall composition was unique for each mill. When comparing process ater and biofilm at different locations within one of the mills, we bserved a separation according to location and sample type, with the iofilm from the paper machine being most different. 16S rRNA gene clone ibraries were generated and 404 clones were screened by RFLP analysis. rouping of RFLP patterns confirmed that the biofilm from the paper achine was most different. A total of 99 clones representing all RFLP atterns were analyzed, resulting in sequences recovered from nine acterial phyla, including two candidate phyla. Bacteroidetes epresented 45% and Actinobacteria 23% of all the clones. Sequences with imilarity to organisms implicated in biofouling, like Chryseobacterium pp. and Brevundimonas spp., were recovered from all samples even though he mill had no process problems during sampling, suggesting that they re part of the natural paper mill community. Moreover, many sequences howed little homology to as yet uncultivated bacteria implying that aper mills are interesting for isolation of new organisms, as well as or bioprospecting.
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| 2. |
- Önneby, Karin, et al.
(författare)
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Effects of di- and polysaccharide formulations and storage conditions on survival of freeze-dried Sphingobium sp.
- 2013
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Ingår i: World Journal of Microbiology & Biotechnology. - : Springer Science and Business Media LLC. - 0959-3993 .- 1573-0972. ; 29:8, s. 1399-1408
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Tidskriftsartikel (refereegranskat)abstract
- In this study we have compared the ability of the organic polymers Ficoll and hydroxyethylcellulose (HEC) and the disaccharides sucrose and trehalose to support cell survival during freeze-drying and subsequent storage of a gram-negative Sphingobium sp. In addition to determination of viability rates, cell integrity was evaluated using lipid peroxidation and RNA quality assays for the different storage conditions and formulation compositions. All formulations resulted in high initial cell survival rates after freeze-drying. However, the disaccharide formulations were superior to the polymer-based formulations in supporting cell survival during storage with the exception of Ficoll that upon storage under vacuum yielded bacterial survival rates equal to that of sucrose. Storage in the presence of both oxygen and moisture was detrimental for bacterial survival in all formulations tested, however, lipid peroxidation or RNA damages were not the controlling mechanisms for cell death in this system. The ability of Ficoll and HEC to support cell survival during freeze-drying show that organic polymers, expected to lack the water replacing capability of e.g. disaccharides, can successfully be used as lyoprotectants. For storage under vacuum conditions we suggest that the intracellular amount of sugars (i.e. trehalose), or other protective native cell components, is sufficient for a basic protection inside the bacteria cell and that the amorphous state is the most important aspect of the formulation excipient. However, when exposed to oxygen and moisture during storage this protection is not sufficient to prevent cell degeneration.
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| 3. |
- Hallström, Elinor, et al.
(författare)
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Dietary environmental impacts relative to planetary boundaries for six environmental indicators – A population-based study
- 2022
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Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 373
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Tidskriftsartikel (refereegranskat)abstract
- The environmental impact of Swedish diets was assessed for six indicators (greenhouse gas [GHG] emissions, cropland use, nitrogen application, phosphorus application, consumptive water use and extinction rate), using self-reported food intake within two population-based cohorts of men and women, 56–96 years of age. The dietary environmental impact was assessed in relation to per capita planetary boundaries, overall and by population subgroups, addressing the relative importance of specific foods and food groups. The total average dietary impact exceeded the planetary boundaries by 1.6 to 4-fold for five of the six environmental indicators; consumptive water use did not exceed the boundaries. Comparing the highest with lowest quintiles of the population impact showed >2.5-fold differences across all environmental indicators. Of the diet's total average environmental impact, animal-based, plant-based and discretionary foods accounted for 28–83%, 8–40% and 9–37%, respectively, across the six indicators. Animal-based foods dominated the impact on GHG emissions, cropland use and nitrogen and phosphorus application, while plant-based and discretionary foods contributed more to consumptive water use and extinction rate. Environmental impact was driven predominantly by consumption of red meat, dairy, fresh fruit and coffee. The findings show major challenges in affluent countries that have to be addressed to achieving sustainable food production systems and diets. They provide guidance on critical food groups, environmental indicators and population subgroups to prioritize in future efforts to reduce the environmental impact. © 2022 The Authors
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| 4. |
- Torén, A, et al.
(författare)
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Tractor-driving hours and their relation to self-reported low-back and hip symptoms.
- 2002
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Ingår i: Appl Ergon. - 0003-6870 .- 1872-9126. ; 33:2, s. 139-46
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Tractor driving might be one causal risk factor in the incidence of low-back and hip symptoms among farmers. Information on the annual exposure to tractor driving and its distribution among different work operations is scarce. The purpose of this study was to quantify the total and the annual time driving tractors among Swedish farmers and its distribution into different work operations, and to investigate the risk of low-back and hip symptoms in relation to tractor driving within different work operations. The data were collected from a questionnaire study sent to all farms with acreage more than 10 ha in a county in Sweden. Farmers having farming and/or forestry as their main occupation in 1995 were included in the analysis. The annual tractor-driving time and the percentage distribution within different work operations were calculated for females, males, the total group and four production groups. The risk calculations for low-back and hip symptoms from the variables related to tractor driving were performed on the total group. The results showed that the mean annual tractor-driving time was 472 h. Ploughing was the single most time-consuming work operation but it had no influence on the risk for low-back or hip pain. The results showed that some of the variables investigated related to tractor driving influenced the risk for low-back and hip symptoms.
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| 5. |
- Ameli, A. A., et al.
(författare)
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Hillslope permeability architecture controls on subsurface transit time distribution and flow paths
- 2016
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Ingår i: Journal of Hydrology. - : Elsevier B.V.. - 0022-1694 .- 1879-2707. ; 543, s. 17-30
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Tidskriftsartikel (refereegranskat)abstract
- Defining the catchment transit time distribution remains a challenge. Here, we used a new semi-analytical physically-based integrated subsurface flow and advective–dispersive particle movement model to assess the subsurface controls on subsurface water flow paths and transit time distributions. First, we tested the efficacy of the new model for simulation of the observed groundwater dynamics at the well-studied S-transect hillslope (Västrabäcken sub-catchment, Sweden). This system, like many others, is characterized by exponential decline in saturated hydraulic conductivity and porosity with soil depth. The model performed well relative to a tracer-based estimate of transit time distribution as well as observed groundwater depth–discharge relationship within 30 m of the stream. Second, we used the model to assess the effect of changes in the subsurface permeability architecture on flow pathlines and transit time distribution in a set of virtual experiments. Vertical patterns of saturated hydraulic conductivity and porosity with soil depth significantly influenced hillslope transit time distribution. Increasing infiltration rates significantly decreased mean groundwater age, but not the distribution of transit times relative to mean groundwater age. The location of hillslope hydrologic boundaries, including the groundwater divide and no-flow boundary underlying the hillslope, changed the transit time distribution less markedly. These results can guide future decisions on the degree of complexity that is warranted in a physically-based rainfall–runoff model to efficiently and explicitly estimate time invariant subsurface pathlines and transit time distribution.
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| 6. |
- Bjurhager, Ingela, et al.
(författare)
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State of degradation in archeological oak from the 17th century vasa ship : Substantial strength loss correlates with reduction in (holo)cellulose molecular weight
- 2012
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; :8, s. 2521-2527
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Tidskriftsartikel (refereegranskat)abstract
- In 1628, the Swedish warship Vasa capsized on her maiden voyage and sank in the Stockholm harbor. The ship was recovered in 1961 and, after polyethylene glycol (PEG) impregnation, it was displayed in the Vasa museum. Chemical investigations of the Vasa were undertaken in 2000, and extensive holocellulose degradation was reported at numerous locations in the hull. We have now studied the longitudinal tensile strength of Vasa oak as a function of distance from the surface. The PEG-content, wood density, and cellulose microfibril angle were determined. The molar mass distribution of holocellulose was determined as well as the acid and iron content. A good correlation was found between the tensile strength of the Vasa oak and the average molecular weight of the holocellulose, where the load-bearing cellulose microfibril is the critical constituent. The mean tensile strength is reduced by approximately 40%, and the most affected areas show a reduction of up to 80%. A methodology is developed where variations in density, cellulose microfibril angle, and PEG content are taken into account, so that cell wall effects can be evaluated in wood samples with different rate of impregnation and morphologies.
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| 7. |
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| 8. |
- Forghani, Kamran, et al.
(författare)
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Maximizing value yield in wood industry through flexible sawing and product grading based on wane and log shape
- 2024
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Ingår i: Computers and Electronics in Agriculture. - : Elsevier. - 0168-1699 .- 1872-7107. ; 216
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Tidskriftsartikel (refereegranskat)abstract
- The optimization of sawing processes in the wood industry is critical for maximizing efficiency and profitability. The introduction of computerized tomography scanners provides sawmill operators with three-dimensional internal models of logs, which can be used to assess value and yield more accurately. We present a methodology for solving the sawing optimization problem employing a flexible sawing scheme that allows greater flexibility in cutting logs into products while considering product quality classes influenced by wane defects. The methodology has two phases: preprocessing and optimization. In the preprocessing phase, two alternative algorithms are given that generate and evaluate the potential sawing positions of products by considering the 3D surface of the log, product size requirements, and product quality classes. In the optimization phase, a maximum set-packing problem is solved for the preprocessed data using mixed-integer programming (MIP), aiming to obtain a feasible cut pattern that maximizes value yield. This is implemented in a system named FlexSaw, which takes advantage of parallel computation during the preprocessing phase and utilizes a MIP solver during the optimization phase. The proposed sawing methods are evaluated on the Swedish Pine Stem Bank. Additionally, FlexSaw is compared with an existing tool that utilizes cant sawing. Results demonstrate the superiority of flexible sawing. While the practical feasibility of implementing a flexible way of sawing logs is constrained by the limitations of current sawmill machinery, the potential increase in yield promotes the exploration of alternative machinery in the wood industry.
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| 9. |
- Hallström, Elinor, et al.
(författare)
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Dietary climate impact : Contribution of foods and dietary patterns by gender and age in a Swedish population
- 2021
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 306
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Tidskriftsartikel (refereegranskat)abstract
- Dietary climate impact in a Swedish population (56–95 years old) was estimated based on self-reported food intake from 50 000 men and women within two population-based cohorts and on climate data, covering emissions from farm to fork, for 600 foods representative for the Swedish market. Aims were to assess variation in dietary climate impact between population groups and between food categories. Mean dietary climate impact was 2.0 tons of CO2e/person/year, with about a threefold variation between high and low impact individuals. Food loss and waste accounted for 18%. Older individuals and women on average had lower total dietary climate impact per year, while differences between gender were smaller per 1000 kcal. Climate impact was greatly affected by dietary composition and especially by the content of animal-based and discretionary foods, responsible for 71% and 12% of total climate impact, respectively. Results indicate a large potential for reduced climate impact by adopting realistic dietary patterns. Suggested strategies to reach climate goals include reduction of red meat and prioritising lower impact foods within meat, dairy and seafood categories, limited consumption of discretionary foods and decreased over-consumption of total calories, combined with improvements in production including reduction of food loss and waste.
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| 10. |
- Joffre, Thomas, 1987-, et al.
(författare)
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Characterization of interfacial stress transfer ability in acetylation-treated wood fibre composites using X-ray microtomography
- 2017
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 95, s. 43-49
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Tidskriftsartikel (refereegranskat)abstract
- The properties of the fibre/matrix interface contribute to stiffness, strength and fracture behaviour of fibre-reinforced composites. In cellulosic composites, the limited affinity between the hydrophilic fibres and the hydrophobic thermoplastic matrix remains a challenge, and the reinforcing capability of the fibres is hence not fully utilized. A direct characterisation of the stress transfer ability through pull-out tests on single fibres is extremely cumbersome due to the small dimension of the wood fibres. Here a novel approach is proposed: the length distribution of the fibres sticking out of the matrix at the fracture surface is approximated using X-ray microtomography and is used as an estimate of the adhesion between the fibres and the matrix. When a crack grows in the material, the fibres will either break or be pulled-out of the matrix depending on their adhesion to the matrix: good adhesion between the fibres and the matrix should result in more fibre breakage and less pull-out of the fibres than poor adhesion. The effect of acetylation on the adhesion between the wood fibres and the PLA matrix was evaluated at different moisture contents using the proposed method. By using an acetylation treatment of the fibres it was possible to improve the strength of the composite samples soaked in the water by more than 30%.
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