| 1. |
- Abdulgadir, Alamin, et al.
(författare)
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Performance Simulation of a Composite Filter Material Containing Mechanical Pulp Fibers, Microfibrillated Cellulose, and Cellulose Nanofibers
- 2022
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Ingår i: Proceedings of the International Mechanical Pulping Conference. ; , s. 160-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Nonwoven fibrous materials with reticular support of an interconnected fiber network and a tortuous airflow pathway have been commonly used in filtration applications. To meet the criteria of filter efficiency and performance, the filter materials are recommended to contain different types of fibers such as mechanical pulp fibers, microfibrillated cellulose, cellulose nanofibers, and other polymer or synthetic fibers with a range of dimensions, i.e., length and diameter. Cellulose fibers in filter media possess irregular and complex structures with hollow or collapsed lumen structures owing to their refinement or pulping method. The development of an appropriate filter media model requires information on actual fiber characteristics. In this study, a simulation method was used to investigate the complex microstructures of filter media. The physical parameters such as fiber wall thickness, diameter, length, cross-section shapes, and curliness were obtained from fiber analyzers and scanning electron microscopy. Based on the experimental findings, GeoDict database comprising different types of common fiber models was constructed. 3-Dimensional fibrous models corresponding to the wet-laid binderless filter material were generated. Using the GeoDict modules, the pore size distributions, average pore sizes, air permeability, pressure drop and initial filter efficiency simulations were performed. The simulation results appear to be in close agreement with the experimental results. The incorporation of cellulose nanofibers resulted in reduced average pore sizes and air permeability of the filter material, thus enhancing the initial filter efficiency. The filter media developed a biobased material derived from pulp fibers for advanced applications such as medical facemask, and air filtration purposes.
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| 2. |
- Alimohammadzadeh, Rana, et al.
(författare)
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Improving the mechanical properties of CTMP fibers by combining synergistic organocatalytic/polyelectrolyte complex surface engineering with sulfite pretreatment
- 2022
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Ingår i: Proceedings of the International Mechanical Pulping Conference. ; , s. 149-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Fabrication of paper-based packaging materials is increasing and the challenge is developing a sustainable process to manufacture the materials that can compete with plastics. Employing stronger fiber in production of fiber-based materials improves the efficiency of fabrication process by using a reduced amount of biomass. Cationic starch is a well-known polysaccharide that has been introduced to paper and paperboard fibers to improve the mechanical properties of lignocellulosic fibers. The polyelectrolyte (PE) multilayer method has been popularized as a new and interesting technique to enhance the adsorption of cationic starch on the fiber for improving the strength properties of chemi-thermomechanical pulp (CTMP), chemical and kraft pulps. We have shown in our previous work that the synergistic combination of organocatalysis and PE complexes improved the mechanical properties of CTMP and TMP. In this work, we chose to expand this concept by integrating it with low-dose sulfite pretreatment of wood chips in preparation of CTMP. Thus, CTMP produced by initial sulfite pre-treatment was next surface engineered by synergistic combination of organocatalysis and PE complexes using organic acids as catalysts. The CTMP pulps, which contains 0.1-0.24 wt.% sulfur, produced by our novel pulp-engineering strategy shows a dramatic strength increase (Z- strength: up to 100 %) as compared to no surface engineering. While only sulfite pre-treatment and PE-complex surface engineering were able to improve the strength properties, it was only when the organic catalysts was present that the highest strength improvements were reached. Thus, a clear synergistic effect of the catalyst was observed.
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| 3. |
- Amiri, Neda, et al.
(författare)
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Valuation of carbon sequestration and estimation of co2 emission in the Hyrcanian forests of Iran
- 2021
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Ingår i: Forestry Ideas. - Bulgaria : University of Forestry. - 1314-3905 .- 2603-2996. ; 27:2(62), s. 318-331
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to estimate the aboveground carbon sequestration and the amountof CO2 emissions at logging operation in Hyrcanian forests of Iran. Required data, such as foreststanding stock, annual growth increment of trees, wood density and timber harvesting, werecollected from secondary sources. Allometric equation was used for estimating the carbon sequestration.The amount of CO2 emission was calculated. Results showed that the annual growthper hectare and the amount of carbon sequestration per growth were 3.37 m3·yr-1 and 1.14 t·ha-1,respectively. Results also indicated that the value of aboveground sequestrated carbon and itsnet present value were 71,217.63 (10,000 IRR∙ha-1) and 12,668.28 (10,000 IRR∙ha-1), respectively.Finally, the amount of carbon emission per hectare was calculated, as it was 0.01078 t∙ha-1 peryear. The results of emission and carbon sequestration per hectare of the forest show that notonly logging per hectare of forest will eliminate annual carbon sequestration, but also leads to anincrease in CO2 into the atmosphere due to harvest activity.
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| 4. |
- Anderbrant, Olle, et al.
(författare)
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Attraction of Male Pine Sawflies, Diprion jingyuanensis, to Synthetic Pheromone Candidates: Synergism between Two Stereoisomers
- 2023
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Ingår i: Forests. - : MDPI. - 1999-4907. ; 14:6
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Tidskriftsartikel (refereegranskat)abstract
- The pine sawfly Diprion jingyuanensis Xiao and Zhang (Hymenoptera: Diprionidae) is a serious pest of Pinus tabulaeformis Carr. in the Shanxi, Gansu, and Inner Mongolia provinces in P. R. China. The sex pheromone of D. jingyuanensis was shown to be the propionate ester of 3,7-dimethyl-2-tridecanol. Virgin females contained an approximate 1:3 blend of the pheromone precursors erythro-(2S,3S,7R/S and 2R,3R,7R/S)-3,7-dimethyl-2-tridecanol and threo-(2S,3R,7R/S and 2R,3S,7R/S)-3,7-dimethyl-2-tridecanol, but the exact stereoisomers were not determined. Males responded the strongest to the propionate ester of the two threo-isomers, (2S,3R,7R) and (2S,3R,7S), in electroantennogram (EAG) recordings, followed by a significant EAG response to the (2S,3R,7R) propionate of diprionol (pheromone component of D. similis), whereas the remaining two isomers (2S,3S,7S and 2S,3S,7R) of the propionate ester of 3,7-dimethyl-2-tridecanol and the acetate of the (2S,3R,7R) isomer (one of the two pheromone components of D. pini) did not elicit any significant increase in antennal response. In the field, the strongly EAG-active (2S,3R,7R)-isomer alone was only weakly (but significantly) attractive to D. jingyuanensis males at 100 & mu;g, while the equally EAG- active (2S,3R,7S)-isomer alone at the same loading was 8-14 times more attractive than was the (2S,3R,7R)-isomer alone. Traps baited with the same amounts of the two threo-isomers ((2S,3R,7R) and (2S,3R,7S), 100 & mu;g + 100 & mu;g) caught significantly more males than did traps baited with other isomers, either of the two isomers alone or other proportions of the two isomers. Thus, the (2S,3R,7S)-isomer is considered as a strong and essential sex-attractant component for D. jingyuanensis males, whereas the (2S,3R,7R)-isomer is a weak but synergistic sex-attractant. This is one of the few examples of a pine sawfly responding significantly stronger to a binary blend of stereoisomers in a synergistic fashion than to a single stereoisomer alone.
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| 5. |
- Andersson, Erik, et al.
(författare)
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Ambio fit for the 2020s
- 2022
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Ingår i: Ambio. - : Springer Nature. - 0044-7447 .- 1654-7209. ; 51:5, s. 1091-1093
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Tidskriftsartikel (refereegranskat)
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| 6. |
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| 7. |
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| 8. |
- Angelstam, Per, et al.
(författare)
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Protecting forest areas for biodiversity in Sweden 1991–2010: the policy implementation process and outcomes on the ground
- 2011
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Ingår i: Silva Fennica. - : Finnish Society of Forest Science. - 0037-5330 .- 2242-4075. ; 45, s. 1111-1133
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Tidskriftsartikel (refereegranskat)abstract
- Swedish forest and environmental policies imply that forests should be managed so that all naturally occurring species are maintained in viable populations. This requires maintenance of functional networks of representative natural forest and cultural woodland habitats. We first review the policy implementation process regarding protected areas in Sweden 1991-2010, how ecological knowledge was used to formulate interim short-term and strategic long-term biodiversity conservation goals, and the development of a hierarchical spatial planning approach. Second, we present data about the amount of formally protected and voluntarily set aside forest stands, and evaluate how much remains in terms of additional forest protection, conservation management and habitat restoration to achieve forest and environmental policy objectives in the long-term. Third, a case study in central Sweden was made to estimate the functionality of old Scots pine, Norway spruce and deciduous forest habitats, as well as cultural woodland, in different forest regions. Finally, we assess operational biodiversity conservation planning processes. We conclude that Swedish policy pronouncements capture the contemporary knowledge about biodiversity and conservation planning well. However, the existing area of protected and set-aside forests is presently too small and with too poor connectivity. To bridge this gap, spatial planning, management and restoration of habitat, as well as collaboration among forest and conservation planners need to be improved.
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| 9. |
- Angelstam, Per, et al.
(författare)
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Sweden does not meet agreed national and international forest biodiversity targets : A call for adaptive landscape planning
- 2020
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Ingår i: Landscape and Urban Planning. - : Elsevier BV. - 0169-2046 .- 1872-6062. ; 202
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Tidskriftsartikel (refereegranskat)abstract
- Loss of forest naturalness challenges the maintenance of green infrastructure (GI) for biodiversity conservation and delivery of diverse ecosystem services. Using the Convention on Biological Diversity's Aichi target #11 with its quantitative and qualitative criteria as a normative model, we aim at supporting landscape planning through a pioneering assessment of the extent to which existing amounts and spatial distributions of High Conservation Value Forests (HCVFs) meet these criteria. Highly forested and committed to both intensive wood production and evidence-based conservation targets of 17–20% protected areas, Sweden was chosen as a case study. Specifically, we estimated the amount, regional representation, and functional connectivity of HCVF patches using virtual bird species, validated the results using field surveys of focal bird species, and assessed conservation target fulfilment. Finally, we linked these results to the regional distribution of forest land ownership categories, and stress that these provide different opportunities for landscape planning. Even if 31% of forest land in Sweden is officially protected, voluntarily set-aside, or not used for wood production now and in the future, we show that applying the representation and connectivity criteria of Aichi target #11 reduces this figure to an effective GI of 12%. When disaggregating the five ecoregions the effective GI was 54% for the sub-alpine forest ecoregion, which hosts EU's last intact forest landscapes, but only 3–8% in the other four ecoregions where wood production is predominant. This results in an increasing need for forest habitat and landscape restoration from north to south. The large regional variation in the opportunity for landscape planning stresses the need for a portfolio of different approaches. We stress the need to secure funding mechanisms for compensating land owners’ investments in GI, and to adapt both the approaches and spatial extents of landscape planning units to land ownership structure.
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| 10. |
- Asadollahi, Mojtaba, et al.
(författare)
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Pathogenicity differences between group I and group II of Botrytis cinerea
- 2011
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Ingår i: Acta Agraria Debreceniensis. - : University of Debrecen/ Debreceni Egyetem. - 1587-1282 .- 2416-1640. ; :43, s. 81-85
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Botrytis cinerea has been reported as a species complex containing two cryptic species, groups I (Botrytis pseudocinerea) and II (B. cinerea sensu stricto). In order to compare the pathogenicity of group I and group II of B. cinerea, we have selected 4 strains of group I and 4 strains of group II. The results demonstrated that competitive infection of group II was more on grape, cucumber and paprika leaves, than group I. However the results on bean leaves did not correlate the applied B. cinerea group.
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