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Adamopoulos, StergiosORCID iD iconorcid.org/0000-0002-6909-2025
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Publications (10 of 168) Show all publications
Jones, G., Ulan, M., Liziniewicz, M., Lindeberg, J. & Adamopoulos, S. (2024). Relating estimates of wood properties of birch to stem form, age and species. Journal of Forestry Research, 35(1), Article ID 14.
Open this publication in new window or tab >>Relating estimates of wood properties of birch to stem form, age and species
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2024 (English)In: Journal of Forestry Research, ISSN 1007-662X, E-ISSN 1993-0607, Vol. 35, no 1, article id 14Article in journal (Refereed) Published
Abstract [en]

Birch has long suffered from a lack of active forest management, leading many researchers to use material without a detailed management history. Data collected from three birch (Betula pendula Roth, B. pubescens Ehrh.) sites in southern Sweden were analyzed using regression analysis to detect any trends or differences in wood properties that could be explained by stand history, tree age and stem form. All sites were genetics trials established in the same way. Estimates of acoustic velocity (AV) from non-destructive testing (NDT) and predicted AV had a higher correlation if data was pooled across sites and other stem form factors were considered. A subsample of stems had radial profiles of X-ray wood density and ring width by year created, and wood density was related to ring number from the pith and ring width. It seemed likely that wood density was negatively related to ring width for both birch species. Linear models had slight improvements if site and species were included, but only the youngest site with trees at age 15 had both birch species. This paper indicated that NDT values need to be considered separately, and any predictive models will likely be improved if they are specific to the site and birch species measured.

Place, publisher, year, edition, pages
Springer, 2024
Keywords
Acoustic velocity, Non-destructive testing, Predictive models, Regression analysis, Wood density
National Category
Forest Science Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-126764 (URN)10.1007/s11676-023-01669-4 (DOI)001117570200007 ()2-s2.0-85178931158 (Scopus ID)
Available from: 2024-01-16 Created: 2024-01-16 Last updated: 2024-02-06Bibliographically approved
Neitzel, N., Hosseinpourpia, R. & Adamopoulos, S. (2023). A dialdehyde starch-based adhesive for medium-density fiberboards. BioResources, 18(1), 2155-2171
Open this publication in new window or tab >>A dialdehyde starch-based adhesive for medium-density fiberboards
2023 (English)In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 18, no 1, p. 2155-2171Article in journal (Refereed) Published
Abstract [en]

Bio-based adhesives have gained considerable attention in the last years as more sustainable and healthier alternatives to the formaldehyde-based adhesives used today in wood-based panel manufacturing. In this study, dialdehyde starch (DAS) with various aldehyde contents was prepared by using sodium metaperiodate as an oxidizing agent. Characterizations were performed by employing Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and thermal stability analysis. Different adhesive compositions were used for making medium-density fiberboard (MDF) panels. They were based on DAS (12 wt% based on fiber), emulsifiable diphenylmethane diisocyanate (eMDI, 2-4 wt% based on DAS), and microfibrillated cellulose (MFC, 0.5-1.0 wt% based on DAS). Fibers and the adhesive components were mixed with a combination of dry mixing and wet spraying. The physical and mechanical properties of MDF panels bonded with different DAS-based adhesives were compared with those of melamine urea-formaldehyde (MUF) adhesive and sole eMDI. The results showed that the MDF panels made with DAS-MFC-eMDI of 99.52% bio-based content showed comparable properties to standard panels with a commercial MUF adhesive. It was implied that DAS in the presence of small amount of eMDI can create strong bonds with wood fibers, while an additional positive effect on bonding was due to the contact surface enlargement of MFC.

Place, publisher, year, edition, pages
NC State University, 2023
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-119055 (URN)10.15376/biores.18.1.2155-2171 (DOI)000992668900039 ()2-s2.0-85149145425 (Scopus ID)
Funder
Swedish Research Council Formas
Available from: 2023-02-04 Created: 2023-02-04 Last updated: 2023-08-14Bibliographically approved
Neitzel, N., Eder, M., Hosseinpourpia, R., Walther, T. & Adamopoulos, S. (2023). Chemical composition, particle geometry, and micro-mechanical strength of barley husks, oat husks, and wheat bran as alternative raw materials for particleboards. Materials Today Communications, 36, Article ID 106602.
Open this publication in new window or tab >>Chemical composition, particle geometry, and micro-mechanical strength of barley husks, oat husks, and wheat bran as alternative raw materials for particleboards
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2023 (English)In: Materials Today Communications, ISSN 2352-4928, Vol. 36, article id 106602Article in journal (Refereed) Published
Abstract [en]

Particleboards are used worldwide in various industry segments, like construction and furniture production. Nevertheless, increase in wood prices and logistical challenges urge the particleboard industry to find alternative raw materials. By-products and residues from the agricultural and food industries could offer possibilities for material sourcing at a local level. This study aimed to investigate the chemical composition, particle geometry, anatomical structure, and microtensile characteristics of such material, specifically barley husks (BH), oat husks (OH), and wheat bran (WB). Barley and oat husks were found to have comparable hemicelluloses and lignin contents to industrial wood chips but contained more ash. Wheat bran was rich in extractives and showed high buffering capacity. Light microscopy and microcomputed tomography revealed details of leaf structure for BH and OH as well as the multi-layer structure of WB. The ultimate microtensile strength of BH, various OH samples, and WB were respectively 2.77 GPa, 0.84-2.42 GPa, and 1.45 GPa. The results indicated that the studied materials could have potential uses as furnish materials in non-load bearing particleboards, where thermal or acoustic insulation properties are desirable.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
agro-industry residues, chemical composition, particle geometry, SEM, x-ray microcomputed tomography, microtensile strength
National Category
Composite Science and Engineering Agricultural Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-123200 (URN)10.1016/j.mtcomm.2023.106602 (DOI)001038281900001 ()2-s2.0-85164218316 (Scopus ID)
Funder
Swedish Research Council Formas, 2018-01371
Available from: 2023-07-06 Created: 2023-07-06 Last updated: 2023-08-17Bibliographically approved
Kuqo, A., Mayer, A. K., Amiandamhen, S. O., Adamopoulos, S. & Mai, C. (2023). Enhancement of physico-mechanical properties of geopolymer particleboards through the use of seagrass fibers. Construction and Building Materials, 374, Article ID 130889.
Open this publication in new window or tab >>Enhancement of physico-mechanical properties of geopolymer particleboards through the use of seagrass fibers
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2023 (English)In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 374, article id 130889Article in journal (Refereed) Published
Abstract [en]

Two types of geopolymer-bonded boards were produced using initial wetting of lignocellulosic aggregates followed by dry mixing and hot-pressing. Boards were prepared by incorporating large fractions of lignocellulosic material (up to 50 wt%). Geopolymer particleboards (GP) were produced using wood particles whereas geopolymer sandwich boards (GSB) were produced from wood particles and seagrass fibers, with the latter allocated in the outer layers. Inclusion of seagrass fibers was found to enhance bending strength and toughness of GSB by up to 20 and 40 % respectively. The bending strength tended to increase with the addition of lignocellulosic aggregates, reaching up to 8.9 N mm−2. Fire resistance of GSB was slightly higher compared to GP. Further investigations such as FT-IR, XRD analysis and visual examination by digital microscopy showed an adequate degree of geopolymerization and mixing of the precursor and alkaline activator, indicating the high effectiveness of the mixing technique.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Aggregates, Bending strength, Fibers, Geopolymers, Hot pressing, Inorganic polymers, Plants (botany), ’Dry’ [, Geopolymer, Geopolymer particleboard, Lignocellulosic aggregates, Physicomechanical properties, Posidonia oceanica, Posidonium oceanicum fiber, Sandwich boards, Seagrasses, Wood particles, Mixing
National Category
Wood Science Paper, Pulp and Fiber Technology
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-123737 (URN)10.1016/j.conbuildmat.2023.130889 (DOI)000954527600001 ()2-s2.0-85149709991 (Scopus ID)
Available from: 2023-08-16 Created: 2023-08-16 Last updated: 2023-09-12Bibliographically approved
Ahmed, S. A., Hosseinpourpia, R. & Adamopoulos, S. (2023). Micro-Fibrillated Cellulose in Lignin–Phenol–Formaldehyde Adhesives for Plywood Production. Forests, 14(11), Article ID 2249.
Open this publication in new window or tab >>Micro-Fibrillated Cellulose in Lignin–Phenol–Formaldehyde Adhesives for Plywood Production
2023 (English)In: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 14, no 11, article id 2249Article in journal (Refereed) Published
Abstract [en]

Petrochemical-based phenol–formaldehyde (PF) adhesives are widely used in plywood production. To substitute phenol in the synthesis of PF adhesives, lignin can be added due to its structural similarity to phenol. Moreover, micro-fibrillated cellulose (MFC) can further enhance the bond performance, mechanical properties, and toughness of adhesive systems. Thus, the aim of this study was to evaluate the adhesion performance of lignin–PF (LPF) adhesives reinforced with MFC. In LPF formulations, three levels of MFC (0, 15, and 30 wt% based on the total solid content of adhesives) were added to the homogenous adhesive mixture. Three-layer plywood panels from birch (Betula pendula Roth.) veneers were assembled after hot pressing at 130 °C under two pressing durations, e.g., 60 and 75 s/mm. Tensile shear strength was measured at dry (20 °C and 65% RH) and wet conditions (water soaked at room temperature for 24 h). The results indicated that the addition of lignin reduced the strength of LPF adhesives in both dry and wet conditions compared to the control PF adhesive. However, MFC reinforcement enhanced the shear strength properties of the plywood. Furthermore, a longer pressing time of 75 s/mm slightly increased the shear strength.

Place, publisher, year, edition, pages
Switzerland: MDPI, 2023
Keywords
bio-based adhesives; tensile shear strength; viscosity; adhesive penetration; birch veneer
National Category
Composite Science and Engineering Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-125638 (URN)10.3390/f14112249 (DOI)001118094100001 ()2-s2.0-85178357748 (Scopus ID)
Available from: 2023-11-15 Created: 2023-11-15 Last updated: 2024-01-18Bibliographically approved
Fagerberg, N., Seifert, S., Seifert, T., Lohmander, P., Alissandrakis, A., Magnusson, B., . . . Bader, M.-F. K. F. (2023). Prediction of knot size in uneven-sized Norway spruce stands in Sweden. Forest Ecology and Management, 544, Article ID 121206.
Open this publication in new window or tab >>Prediction of knot size in uneven-sized Norway spruce stands in Sweden
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2023 (English)In: Forest Ecology and Management, ISSN 0378-1127, E-ISSN 1872-7042, Vol. 544, article id 121206Article in journal (Refereed) Published
Abstract [en]

The size of knots is negatively correlated with bending strength in sawn timber and it is therefore used as a quality grading criterion in national roundwood grading standards. Some standards even use the size of the largest knot as the sole estimate for individual log knottiness. The size of knots is determined by crown horizontal extension, which in turn is dependent on the impact of competing trees. Thus, with knot size models that are competition-dependent, roundwood quality due to knottiness can be simulated for different management al-ternatives. However, these types of models, calibrated on uneven-sized Norway spruce in Fennoscandia, are currently not available. Therefore, the objective of this study is to develop a competition-dependent model framework for prediction of the largest knot size per stem height section, for application within uneven-sized Norway spruce stands. Data from terrestrial laser scanning of an uneven-sized stand in southern Sweden are used to calibrate a modular prediction framework, consisting of interlinked allometric statistical models. Alternative framework sub-models are presented and the preferred model combination can be selected according to context and available input data. The flexible modular format enables further development of separate sub-components for adaptation to growing conditions not covered by the current calibration range.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Branch model, Stem quality, Uneven-aged, Picea abies, Continuous cover forestry, Crown shape
National Category
Forest Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-124635 (URN)10.1016/j.foreco.2023.121206 (DOI)001056125800001 ()2-s2.0-85163563754 (Scopus ID)
Available from: 2023-09-15 Created: 2023-09-15 Last updated: 2023-10-11Bibliographically approved
Jiang, W., Adamopoulos, S., Hosseinpourpia, R., Walther, T. & Medved, S. (2023). Properties and Emissions of Three-Layer Particleboards Manufactured with Mixtures of Wood Chips and Partially Liquefied Bark. Materials, 16(5), Article ID 1855.
Open this publication in new window or tab >>Properties and Emissions of Three-Layer Particleboards Manufactured with Mixtures of Wood Chips and Partially Liquefied Bark
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2023 (English)In: Materials, E-ISSN 1996-1944, Vol. 16, no 5, article id 1855Article in journal (Refereed) Published
Abstract [en]

Partial liquefaction of residual biomass shows good potential for developing new materials suitable for making bio-based composites. Three-layer particleboards were produced by replacing virgin wood particles with partially liquefied bark (PLB) in the core or surface layers. PLB was prepared by the acid-catalyzed liquefaction of industrial bark residues in polyhydric alcohol. The chemical and microscopic structure of bark and residues after liquefaction were evaluated by means of Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM), while the particleboards were tested for their mechanical and water-related properties, as well as their emission profiles. Through a partial liquefaction process, some FTIR absorption peaks of the bark residues were lower than those of raw bark, indicating hydrolysis of chemical compounds. The surface morphology of bark did not change considerably after partial liquefaction. Particleboards with PLB in the core layers showed overall lower densities and mechanical properties (modulus of elasticity, modulus of rupture, and internal bond strength), and were less water-resistant as compared to the ones with PLB used in the surface layers. Formaldehyde emissions from the particleboards were 0.284–0.382 mg/m2·h, and thus, below the E1 class limit required by European Standard EN 13986:2004. The major emissions of volatile organic compounds (VOCs) were carboxylic acids as oxidization and degradation products from hemicelluloses and lignin. The application of PLB in three-layer particleboards is more challenging than in single-layer boards as PLB has different effects on the core and surface layers.

Place, publisher, year, edition, pages
MDPI, 2023
National Category
Wood Science Polymer Technologies Polymer Chemistry
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-119542 (URN)10.3390/ma16051855 (DOI)000947405900001 ()2-s2.0-85149814967 (Scopus ID)
Available from: 2023-02-24 Created: 2023-02-24 Last updated: 2024-01-12Bibliographically approved
Neitzel, N., Hosseinpourpia, R., Walther, T. & Adamopoulos, S. (2022). Alternative Materials from Agro-Industry for Wood Panel Manufacturing—A Review. Materials, 15(13), 4542-4542
Open this publication in new window or tab >>Alternative Materials from Agro-Industry for Wood Panel Manufacturing—A Review
2022 (English)In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 15, no 13, p. 4542-4542Article in journal (Refereed) Published
Abstract [en]

The growing demand for wood-based panels for buildings and furniture and the increasing worldwide concern for reducing the pressure on forest resources require alternatives to wood raw materials. The agricultural industry not only can provide raw materials from non-wood plants but also numerous residues and side streams. This review supplies an overview of the availability, chemical composition, and fiber characteristics of non-wood lignocellulosic materials and agricultural residues, i.e., grow care residues, harvest residues, and process residues, and their relevance for use in wood panel manufacturing. During the crop harvest, there are millions of tons of residues in the form of stalks, among other things. Usually, these are only available seasonally without using storage capacity. Process residues, on the other hand, can be taken from ongoing production and processed further. Fiber characteristics and chemical composition affect the panel properties. Alternatives to wood with long fibers and high cellulose content offer sufficient mechanical strength in different panel types. In general, the addition of wood substitutes up to approximately 30% provides panels with the required strength properties. However, other parameters must be considered, such as pressing temperature, adhesive type, press levels, and pretreatments of the raw material. The search for new raw materials for wood panels should focus on availability throughout the year, the corresponding chemical requirements and market competition. Panel type and production process can be adapted to different raw materials to fit niche products.

Place, publisher, year, edition, pages
MDPI, 2022
Keywords
agricultural residues; wood panels; particleboard; straw; stalks; sustainability
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-115335 (URN)10.3390/ma15134542 (DOI)000825655500001 ()35806665 (PubMedID)2-s2.0-85133459662 (Scopus ID)
Projects
Agro-industry feedstocks and side streams for increasing the sustainability of wood panel production
Funder
Swedish Research Council Formas, 2018-01371
Available from: 2022-07-13 Created: 2022-07-13 Last updated: 2023-08-14Bibliographically approved
Ahmed, S. A., Hosseinpourpia, R., Brischke, C. & Adamopoulos, S. (2022). Anatomical, Physical, Chemical, and Biological Durability Properties of Two Rattan Species of Different Diameter Classes. Forests, 13(1), Article ID 132.
Open this publication in new window or tab >>Anatomical, Physical, Chemical, and Biological Durability Properties of Two Rattan Species of Different Diameter Classes
2022 (English)In: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 13, no 1, article id 132Article in journal (Refereed) Published
Abstract [en]

Rattan cane is an important forest product with economic value. Its anatomical, physical, and biological properties vary with the cane height. This makes it difficult to select the appropriate cane diameter for harvesting. Understanding the material properties of rattan cane with different diameter sizes is important to enhance its utilization and performance for different end uses. Thus, the present study was performed on two rattan species, Calamus zollingeri and Calamus ornatus, at two different cane heights (bottom/mature and top/juvenile). Calamus zollingeri was studied at diameter classes of 20 mm and 30 mm, while Calamus ornatus was analyzed at a diameter class of 15 mm. The anatomical properties, basic density, volumetric swelling, dynamic moisture sorption, and biological durability of rattan samples were studied. The results showed that C. zollingeri with a 20 mm diameter exhibited the highest basic density, hydrophobicity, dimensional stability, and durability against mold and white-rot (Trametes versicolor) fungi. As confirmed by anatomical studies, this could be due to the higher vascular bundle frequency and longer thick-walled fibers that led to a denser structure than in the other categories. In addition, the lignin content might have a positive effect on the mass loss of different rattan canes caused by white-rot decay.

Place, publisher, year, edition, pages
Switzerland: MDPI, 2022
Keywords
Calamus zollingeri; Calamus ornatus; dynamic vapor sorption; basic density; volumetric swelling; white rot; mold
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-109313 (URN)10.3390/f13010132 (DOI)000757578800001 ()2-s2.0-85140985063 (Scopus ID)2022 (Local ID)2022 (Archive number)2022 (OAI)
Available from: 2022-01-17 Created: 2022-01-17 Last updated: 2023-05-02Bibliographically approved
Sivrikaya, H., Rehbein, M., Divos, F., Adamopoulos, S. & Hosseinpourpia, R. (2022). Changes in topochemistry and mechanical properties of Beech (Fagus orientalis L.) by natural fungus infestation. In: International Research Group on Wood Protection (IRG-WP) 29 May-2 June, Bled, Slovenia: . Paper presented at International Research Group on Wood Protection (IRG-WP) 29 May-2 June, Bled, Slovenia. IRG, Article ID IRG/WP 22-10986.
Open this publication in new window or tab >>Changes in topochemistry and mechanical properties of Beech (Fagus orientalis L.) by natural fungus infestation
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2022 (English)In: International Research Group on Wood Protection (IRG-WP) 29 May-2 June, Bled, Slovenia, IRG , 2022, article id IRG/WP 22-10986Conference paper, Published paper (Refereed)
Abstract [en]

Beech is one of the major hardwood species in Europe. It is, however, highly susceptible to fungal attack both in the fresh state and during the storage. Understanding the alteration in chemical and mechanical properties of beech wood during the initial degradation state can lead to improved raw material utilization. Therefore, UV-microspectrophotometer (UMSP) and High-Performance Liquid Chromatography (HPLC) were employed to study the chemical changes in beech (Fagus Orientalis L.) samples infested naturally by white rot fungi. The mechanical properties of infested beech were also determined and compared with the sound wood. The UMSP showed an apparent degradation in the region of the S3 and the S2 layers. HPLC analysis illustrated that catechin was the main component both in sound and infested beech wood. Considerable reductions in the mechanical strengths, bending properties and compression strength, were also apparent due to infestation.

Place, publisher, year, edition, pages
IRG, 2022
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-115707 (URN)
Conference
International Research Group on Wood Protection (IRG-WP) 29 May-2 June, Bled, Slovenia
Available from: 2022-08-10 Created: 2022-08-10 Last updated: 2023-05-02Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6909-2025

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