TY - JOUR A1 - Sanne, Moritz A1 - Ahn-Ercan, Gudrun A1 - Pfriem, Alexander T1 - A Mathematical Solution for Calculating the Springback of Laminated Beech Stacks Molded within the Elastic Range JF - Forests N2 - The springback effect in molded wood laminations within the elastic range has, to date, not yet been mathematically described. Once cured, residual internal stresses within the laminations cause the final form to deviate from that of the die. Test pieces of beech laminations of 1 mm, 2 mm and 4 mm thicknesses and stack sizes of between 2 and 16 laminations were used. The elasticity value of each stack was obtained using non-glued laminations in a three-point bending test within the elastic region. The laminations were glued with polyurethane resin and mounted in a radius form die. The stress induced by the die onto the stack is within the elastic region of the material without any prior chemical or physical plasticisation of the wood. After curing was complete and the laminations removed from the die, the actual radius was calculated using a circular equation within the CAD program, using three measurement points taken from the stack. The radius of the die within the limits of this study has a negligible effect when predicting the springback of the stack. The exponential correlation between springback and the number of laminations, was used to calculate the springback effect on molded laminated stacks. KW - elasticity value of lamination stacks KW - form relaxation KW - shape Distortion KW - springback KW - wood moldings Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-2335 SN - 1999-4907 IS - 11 (7) PB - MDPI ER - TY - JOUR A1 - Munier, Leo Felix A1 - Franke, Tom A1 - Herold, Nadine A1 - Pfriem, Alexander T1 - Humidity's Effect on the Dynamic-mechanical Behavior of Phenol-formaldehyde Impregnated Beech Wood Veneer JF - BioResources N2 - The dynamic-mechanical behavior of phenol-formaldehyde-impregnated beech wood (Fagus sylvatica L.) veneers was evaluated at various relative humidities. The aim was to identify the plasticizing effects of moisture on phenol-formaldehyde-impregnated veneers. Thin beech veneer samples were impregnated with a low and a medium molecular weight phenol- formaldehyde resin. The measurements were performed with a dynamic- mechanical thermal analysis equipped with a humidity generator. The storage modulus and the loss factor of the uncured phenol-formaldehyde- impregnated and the untreated control veneers were determined at a relative humidity of 15%, 60%, and 85% and a constant temperature of 25 °C. The untreated control veneers exhibited the smallest reduction of the normalized storage modulus. In contrast, the phenol-formaldehyde- impregnated samples exhibited a more intense relative reduction of the storage modulus with increasing relative humidity. This effect was more distinct for samples impregnated with low molecular weight phenol- formaldehyde than for those impregnated with medium molecular weight phenol-formaldehyde. In addition, higher solids contents in the resins led to even smaller normalized storage modulus. Consistently, the loss factor indicated a greater softening of the samples with an increasing humidity and higher solids content of the phenol-formaldehyde. KW - DMTA, Humidity sweep, Phenol-formaldehyde, Plasticization, Veneer modification Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-3841 N1 - Offizielle URL: https://bioresources.cnr.ncsu.edu/resources/humiditys-effect-on-the-dynamic-mechanical-behavior-of-phenol-formaldehyde-impregnated-beech-wood-veneer/ IS - 15(1) SP - 1563 EP - 1574 ER - TY - CHAP A1 - Clauder, Lothar A1 - Munk, Christoph A1 - Pfriem, Alexander T1 - The influence of thermal modification on the initial material-brightness (L*), documented by in-situ measurements T2 - European Conference on Wood Modification 2022 N2 - In this study, the influence of the thermal modification on the characteristic brightness of the raw material Alder (Alnus rubra) and Maple (Acer pseudoplatanus) was investigated by spectral photometric in-situ analysis. KW - thermally modified wood KW - brightness (L*) (CIELab*) KW - process control Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-2801 ER - TY - CHAP A1 - Wozniak, Martin A1 - Wulf, Fabian A1 - Pfriem, Alexander T1 - Investigation of a change in the hardness properties of thermally modified beech wood (Fagus sylvatica L) as a result of a 6-week long-term temperature at 120°C and 140°C T2 - European Conference on Wood Modification 2022 N2 - The aim of this study is to investigate the mechanical properties and structural changes of wood during long-term tempering in mild temperatures. As a result of a long-term heat treatment on beech wood (Fagus sylvatica L), the degradation or decomposition reaction of wood-bound cellulose, hemicellulose and lignins in the low temperature range up to 150°C investigated. For this purpose, test series in the dry state are thermally treated over a period of 6 weeks at a temperature of 120°C and 140°C. Weekly, the mass and dimensions of the test specimens are recorded in order to effectively track the density curve. The mechanical resistance of the wood substrate was realized by a hardness measurement in a weekly period. KW - Brinell-hardness KW - Density KW - IR-Spectroscopy KW - thermal wood modification Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-2816 ER - TY - CHAP A1 - Munk, Christoph A1 - Clauder, Lothar A1 - Pfriem, Alexander T1 - Acoustical comparison of two different guitars, made of untreated tropical wood and thermally modified wood, using a frequency response analysis T2 - Northern European Network for Wood Science & Engineering (WSE) N2 - To this day, many guitar makers around the world use primarily tropical woods such as rosewood (Dalbergia spp.) for their production. Due to the current CITES regulation of January 2017 regarding the trade of tropical woods, it becomes inevitable to generate alternative materials with similar material properties to be generated and established. Part of this study is an acoustic comparison of two guitars. One made of untreated tropical wood [Dalbergia nigra Benth.)] and one made of European thermally modified wood (TMT) species. [Pyrus (L.) and Alnus (Mill.)]. The method used allows a significant statement about the acoustic radiation performance of stringed and plucked instruments. The experimental setup consists of an impulse hammer for excitation of a force in the center of the bridge and a microphone for recording the signal radiated by the guitar body at a distance of one meter from the sound hole. A front-end was used to record the data, and further processing was done using analysis software to determine frequency response functions (FRFs) of the two instruments. The FRFs determined can be subdivided into several ranges which contain the different acoustic information about bass range, loudness, clarity, brightness and sharpness of the instruments. Examination of the frequency ranges reveals an acoustic similarity between the two guitars. Slight differences can be seen in the bass and loudness areas, where the guitar from TMT has a higher average level. Clearer differences are offered by the areas of clarity, where the guitar made of tropical wood shows a higher average level. In summary, the method gives an efficient acoustic impression as a function of the natural frequencies of the two guitars. The measured data show similarities and thus comparable acoustic properties of the instruments. However, additional effects such as psychoacoustic sensations or musical taste for the complete acoustic impression of an instrument are also of importance. Therefore, further empirical and fundamental research is needed to obtain a more detailed acoustic impression of the instruments. KW - TMT KW - FRF KW - guitar Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-2850 ER - TY - CHAP A1 - Munk, Christoph A1 - Clauder, Lothar A1 - Pfriem, Alexander T1 - Sound absorption coefficient of thermally modified and unmodified wood species measured in an impedance tube T2 - Northern European Network for Wood Science and Engineering (WSE) - 15th Annual Meeting 2019 N2 - Different parts of the guitar body are made of certain wood species, selected by their specific properties. The sound board, which is mainly made of spruce or cedar, transfers the vibration of the strings to the resonance body by means of the bridge. The sides and the back of the guitar rather reflect the sound of the acoustic vibrations and are predominantly made of tropical hardwoods like palisander, mahogany or ebony species. These species have limited availability and are listed on the CITES Annex I and II. To substitute tropical wood species, thermally modified European wood species with improved acoustic properties and dimensional stability may be used. Although the acoustic reflection of the sides and the back parts of a guitar body is an important property, there is not much knowledge about this reflection behaviour of wood. A few studies like the work of Hong (1989), Kang (2010) or Smardzewski et al. (2013) investigated the sound absorption properties of unmodified wood. Subsequently this study considers the sound absorption coefficients of unmodified and thermally modified European wood species in comparison to an unmodified tropical wood species. KW - TMT KW - sound absorption coefficient KW - impedance tube Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-2890 ER - TY - CHAP A1 - Munk, Christoph A1 - Wohlert, Hauke A1 - Pfriem, Alexander T1 - Investigation of the influence of two different thermal treatment processes on the change of various material properties of spruce resonance wood (Picea abies (L.) Karst.) T2 - Northern European Network for Wood Science and Engineering - 17th Annual Meeting 2021 N2 - In recent years, a large number of different studies have shown that a variety of positive property changes can be achieved by thermally treating spruce resonance wood. Various methods have been established, which differ mainly in the choice of treatment atmosphere, but also in the associated treatment duration and temperature. Part of the present investigation was to compare a thermal-vacuum process with a process which takes place in an oxygen-reduced atmosphere, with regard to various property changes. The results show that both processes achieved similar results in terms of dynamic acoustic property changes. Larger differences were found with regard to moisture behavior and color change. KW - TMT KW - spruce resonance wood KW - acoustic properties KW - CIELab Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-2909 ER - TY - CHAP A1 - Munk, Christoph A1 - Pfriem, Alexander T1 - Influence of thermal modification and subsequent linseed oil impregnation on the sound propagation velocity and related acoustic properties of various wood species T2 - Tenth European Conference on Wood Modification N2 - In the field of instrument making, the use of indigenous wood species is becoming more and more important due to the increasing environmental awareness of instrument makers and their customers. As the properties of some of these wood species cannot meet the high demands of this field of application, processes are being sought that can achieve improvements. In recent years, many studies have shown that different modification methods, such as furfurylation, thermal treatment, densification or impregnation methods, can partly improve wood properties such as elasticity, strength values, damping behaviour, but also moisture behaviour and wood moisture content significantly. The extent to which different modification processes and their positive changes in properties can be combined with each other and thus achieve further improvements will become increasingly important in the future, not only in instrument making but also in other areas of application. Therefore, this study investigated the influence of thermal treatment followed by linseed oil impregnation of wood on its sound propagation velocity and the associated acoustic properties of characteristic impedance and acoustic radiation. KW - TMT KW - linseed oil impregnation KW - sound propagation velocity KW - acoustic properties Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-2916 ER - TY - CHAP A1 - Munk, Christoph A1 - Pfriem, Alexander T1 - Influence of residual oxygen content during thermal modification process on mass loss, brightness colour and dynamic Young´s modulus of Fagus sylvatica (L.) T2 - 18th Annual Meeting of the Northern European Network for Wood Science and Engineering, 21-22 September 2022, Göttingen, Germany N2 - The thermal modification of wood is considered to be an environmentally friendly and cost-effective treatment process, which has been able to establish itself in many areas of application due to its positive effect on a whole range of different material properties through a wide variety of process designs. In addition to heat transfer and pressure, closed and open systems differ primarily in the choice of treatment atmosphere mainly used to prevent combustion (Sandberg et al. 2021). Although many studies in recent years have investigated influencing process parameters such as temperature, pressure or treatment duration, there exists a knowledge gap regarding the influence of the treatment atmosphere or its behaviour during the treatment process (Candelier et al. 2016). Therefore, this study aims to analyse different oxygen-nitrogen concentrations in the treatment atmosphere at different residual oxygen levels during the process duration and their influence on different property parameters of Fagus sylvatica (L.). KW - beech wood, thermal modification, nitrogen, oxygen, mass loss, MOE, CIELab Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-3582 SP - 1 EP - 3 ER - TY - CHAP A1 - Bender, Tobias A1 - Munk, Christoph A1 - Damay, Jérémie A1 - Jousserand, Michael A1 - Gérardin, Philippe A1 - Pfriem, Alexander T1 - The Effect of Thermal Treatment of Sycamore Maple (Acer Pseudoplatanus L.) prior to Impregnation with Furfuryl Alcohol, regarding Homogeneity and Swelling Behaviour T2 - 18th Annual Meeting of the Northern European Network for Wood Science and Engineering, 21-22 September 2022, Göttingen, Germany N2 - Impregnation of wood with certain chemical compounds is a well established method to improve its physical and mechanical properties. However, the result is often not quite homogeneous. This study examines the effect of two varying thermal treatments on the impregnability of sycamore maple (Acer Pseudoplatanus L.) with furfuryl alcohol (FA), and on the resulting Anti-Swelling-Efficiency (ASE). KW - TMT, Furfuryl Alcohol, ASE, Maple, impregnability Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-3597 SP - 1 EP - 1 ER - TY - CHAP A1 - Wozniak, Martin A1 - Wulf, Fabian A1 - Munier, Leo Felix A1 - Mund, Axel A1 - Pfriem, Alexander ED - Wagenführ, Andrè T1 - Reduce, Reuse, Recycle im Möbelsektor T2 - Tagungsband des 20. Holztechnologischen Kolloquiums Dresden 28.-29. April 2022 N2 - Aufgrund von Rohstoffknappheit auch bei nachwachsenden Rohstoffen kann das Recyceln von Holz und Holzwerkstoffen auch im Möbelsektor nur an vorletzter Stelle, vor der thermischen Verwertung, stehen. Davor gilt es, schon bei der Produktion den Materialeinsatz zu reduzieren bzw. Möbel so zu gestalten, dass eine verlängerte Nutzung möglich ist. Insgesamt muss die Produktnutzung intensiviert werden. Dafür sind unter anderem geeignete Businessmodelle erforderlich. Hiermit beschäftigt sich das Projekt PERMA an der HNEE. Wird Holz dann zum Altholz, muss die Nachnutzungsquote deutlich erhöht werden. Mit der Identifizierung und Indexierung von Altholz befasst sich daher das Kooperations-projekt WIn-Altholz. Sind allerdings Holzspan- und Holzfaserwerkstoffe beschä-digt oder werden nicht mehr benötigt, gibt es bisher keine sinnvollen Nachnut-zungsszenarien. Das Forschungsprojekt „Respan“ will nun ein Recyclingverfahren entwickeln, dass die Nachnutzung möglichst aller Bestandteile der Werkstoffe realisiert. KW - Holzwerkstoff KW - Kreislaufwirtschaft KW - Möbel KW - Recycling KW - Ressourceneffizienz Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-2760 SN - 978-3-86780-705-0 SP - 79 EP - 87 PB - Selbstverlag TU Dresden CY - Dresden ER - TY - GEN A1 - Sanne, Moritz A1 - Kampe, Anja A1 - Lenz, Claudia A1 - Gossel, Stefan A1 - Wagner, Sabine A1 - Haibel, Astrid A1 - Melcher, Eckhard A1 - Leu, Carsten A1 - Pfriem, Alexander A1 - Lautner, Silke T1 - Introduction of shock wave technology to fir wood preservation T2 - International Wood Products Journal N2 - Similar to a normal wave, a shock wave travels as energy through matter but it causes an abrupt rise of pressure, temperature and density. In this study, the influence of shock waves on wood structure were investigated in the light of possible future industrial utilization e.g. timber impregnating treatment. The constructed autoclave is capable of creating shock waves either by an electrical pulse breakdown of a spark gap arrangement or by electromagnetic actuators. The penetration depths of the fir wood test samples were measured using light microscopy, SEM and micro-computed tomography. Our results showed that by varying the intensity of the incident shock wave, the distance between the shock wave generating device and the test sample, and/or the orientation of test sample in relation to the shockwave, the wood tissue structure had been heavily disintegrated or hardly affected at all. An improvement on impregnation could not be found. KW - Shock wave; pressure pulse; wood impregnation; X-ray computed microtomography; GIS for area calculation Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-4536 SN - 2042-6445 VL - 12 IS - 1 SP - 3 EP - 6 PB - Taylor & Francis ER - TY - JOUR A1 - Popescu, Carmen-Mihaela A1 - Pfriem, Alexander T1 - Treatments and modification to improve the reaction to fire of wood and wood based products—An overview JF - Fire and Materials N2 - Wood and wood-based products are widely used for structural building elements, but due to their composition, they are susceptible of combusting if exposed to fire. Fire safety is an important issue of building safety, especially when the building's fire load contents enhance the risks of fire spread. Therefore, the involved materials are very important to address the fire safety requirements. When existing timber structures are involved, the most usual way to improve its reaction to fire is to treat wood with fire retardant materials. The idea of this paper is to give an overall overview, on the existing fire-retardant and intumescent coating materials, modification, and treatments that can be applied to wood and wood-based products in order to improve their reaction to fire. KW - fire retardant; intumescent systems; reaction to fire; wood modification; wood treatment Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-4541 SN - 0308-0501 VL - 44 IS - 1 SP - 100 EP - 111 PB - Wiley ER - TY - JOUR A1 - Sanne, Moritz A1 - Munier, Leo Felix A1 - Förster, Theresa A1 - Dreyer, Christian A1 - Pfriem, Alexander T1 - Einfluss der Schlichte von Celluloseregeneratsfasern auf die Zugscherfestigkeit bei Holzverklebungen JF - Holztechnologie N2 - Es wurden Längszugscherversuch an mit Celluloseregenaratfaser (CRF) verstärktem Epoxidharz durchgeführt. Dabei wurden die Festigkeiten von CRF mit und ohne Schlichtemittel verglichen. Die dauerhafte Ausbildung eines stabilen Verbundes zwischen CRF und Epoxidharz ist weiterhin problematisch. Der Einsatz eines Schlichtemittels wirkt sich nicht auf die Verklebbarkeit der Fasern in der Matrix aus. Sowohl die Werte des Zugscherversuchs als auch die makroskopischen Bruchbilder und die mikroskopischen Analysen von Rissen in der Matrix zeigen keine nennenswerten Unterschiede zwischen beiden untersuchten Varianten. KW - Delaminierung; Epoxid; Längszugscherversuch; Schlichte; Viskose Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-4560 SN - 0018-3881 VL - 61 IS - 5 SP - 38 EP - 42 ER - TY - JOUR A1 - Friedrich, Jan A1 - Lütje-Fournet, Lucas A1 - Gengnagel, Christoph A1 - Pfriem, Alexander T1 - Brandschutztechnische Ertüchtigung von Holzoberflächen durch Pyrolyse: Verbesserung der brandhemmenden Wirkung von pyrolysierten Fassadenhölzern JF - Holztechnologie N2 - Im Rahmen des Forschungsprojektes PyroForCE wurde untersucht, inwieweit sich das Brandverhalten von Fassadenhölzern alleine durch die Erzeugung einer oberflächlichen Pyrolyseschicht so verändern lässt, dass dadurch die Anforderungen für eine Klassifizierung als schwerentflammbarer Baustoff dauerhaft erfüllt werden. Hierzu wurde eine kontinuierlich arbeitende Holzpyrolyseanlage entwickelt, mit der reproduzierbare Pyrolyseflächen auf Prüfkörpern der Holzarten Eiche, Lärche und Fichte erzeugt werden konnten. Durch eine zusätzliche Stabilisierung mit Natriumwasserglas lassen sich sowohl die oberflächliche Abriebfestigkeit erhöhen als auch die Brandschutzwirkung verbessern. So modifizierte Fassadenhölzer können im Single-Burn-Item-Test eine Klassifikatione als "schwerentflammbares" Bauprodukt erreichen. Damit ist das Ziel erreicht, nur durch Oberflächenpyrolyse in VErbindung mit einer Stabilisierung durch rein mineralische Wassergläser das Brandverhalten von Fassadenhölzern so zu verändern, dass eine Zuordnung zu den schwerentflammbaren Baustoffen erreicht werden kann und diese damit als Fassadenmaterial im städtischen Kontext und der Gebäudeklasse 4 und 5 einsetzt werden dürfen. KW - Oberflächenpyrolyse; Fassadenhölzer; Schwerentflammbarkeit; Wassergläser Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-4579 SN - 0018-3881 VL - 62 IS - 2 SP - 23 EP - 35 ER - TY - JOUR A1 - Mensah, Isaac A1 - Ahiekpor, Julius Cudjoe A1 - Herold, Nadine A1 - Bensah, Edem Cudjoe A1 - Pfriem, Alexander A1 - Antwi, Edward A1 - Amponsem, Bright T1 - Biomass and plastic co-pyrolysis for syngas production: Characterisation of Celtis mildbraedii sawdust as a potential feedstock JF - Scientific African N2 - Celtis mildbraedii sawdust (CMS) from Ghana was characterised to investigate its suitability with polyethylene terephthalate (PET) for syngas production via co-pyrolysis. The physical and chemical properties assessed include proximate and ultimate compositions, pH value, higher heating value (HHV), and lignocellulosic composition. Also, the thermal behaviour at different heating rates (5, 10, and 20 K/min) and qualitative prediction of organic compounds of CMS were examined using thermogravimetric analysis (TG/DTG) and NIR spectroscopy techniques, respectively. Results of proximate analysis (moisture = 17.15 ± 0.0 wt.%, ash = 1.13 ± 0.4 wt.%, volatile matter = 68.39 ± 0.4 wt.%, fixed carbon = 13.33 ± 0.8 wt.%); ultimate analysis (C = 48.51 wt.%, H = 6.66 wt.%, N = 0.51 wt.%, S = 0.02 wt.%, O = 44.30 wt.%); pH values (cold phase = 7.60, hot phase = 6.30); HHV (15.37 – 18.03 MJ/kg); and lignocellulosic composition (extractives = 13.80 ± 0.57 wt.%, hemicellulose = 21.95 ± 3.89 wt.%, lignin = 17.35 ± 0.35 wt.%, cellulose = 46.90 ± 2.97 wt.%) were obtained. The maximum mass loss was 83.48% at 289.8 °C at 5 K/min. It was concluded that CMS is a highly potential biomass resource for syngas production with an empirical formula of CH1.64O0.69N0.009S0.0001. KW - Celtis mildbraedii sawdust; Physicochemical; Characterisation; Co-pyrolysis; Syngas; production; Ghana Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-4588 SN - 2468-2276 IS - 16 PB - Elsevier ER - TY - CHAP A1 - Lenz, Claudia A1 - Gollee, Paul A1 - Kühn, Michael A1 - Leich, Christian A1 - Pfriem, Alexander ED - Larnøy, Erik T1 - Artificial irradiation (indoors) of European wood species at different irradiation intensities and at different temperatures T2 - Proceedings of the 19th Meeting of the Northern European Network for Wood Science and Engineering (WSE) 10-12 October 2023 N2 - The background of the topic is to compare the colour changes at different irradiances and temperatures at constant relative humidity. The issue is important because evaluation in terms of irradiance has not been studied in more detail. Irradiation intensities were reported in many studies but tended to have metadata status. The concrete influence of the irradiance on chemical and colour changes in the wood remains open. This paper presents an approach to inquiry-based teaching within a basic research project. Initial results from a large-scale data series are presented here. Irradiance is the term for the total power of incoming electromagnetic energy striking a surface, related to the size of the area, measured in watts per square metre [W/m²]. KW - artificial irradiation KW - wood KW - indoors KW - colour changes KW - CIE L*a*b* Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-7654 N1 - Please check the Repository of papers NORTHERN EUROPEAN NETWORK FOR WOOD SCIENCE AND ENGINEERING https://wsenetwork.org/ SP - 125 EP - 127 PB - Published with support from SNS – The Nordic Forest Research Cooperation Commitee CY - Ås, Norway ER - TY - CHAP A1 - Franke, Tom A1 - Lenz, Claudia A1 - Hertrich, Sven A1 - Kehr, Martin A1 - Kuhnert, Niklas A1 - Munier, Leo Felix A1 - Schultz, Marcus A1 - Stepputat, Sören A1 - Herold, Nadine A1 - Pfriem, Alexander T1 - Künstliche Bewitterung von Buchenfurnier (Fagus sylvatica) imprägniert mit drei Phenolharzen unterschiedlichen Molekulargewichts Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-7609 N1 - 17. Holztechnologisches Kolloquium 28.-29. April 2016, Dresden, Germany ER - TY - GEN A1 - Lenz, Claudia A1 - Wolff, Ian A1 - Beyer, Mario A1 - Koch, Gerald A1 - Pfriem, Alexander T1 - DMP: Predictability of color changes of wood used indoor - A new approach to evaluate the colour change as a function of the radiation dose. Research Data Management Questionnaire N2 - This is a data management plan for the DFG research project "Predictability of color changes of wood used indoor - A new approach to evaluate the color change as a function of the radiation dose". DFG Funding code / Project number: 442135169 Project website: https://gepris.dfg.de/gepris/projekt/442135169?language=en This data management plan (DMP) applies to the Research Data Management Organizer (RDMO) questionnaire and was operated with the RDMO software: https://rdmorganiser.github.io/en/ KW - data management plan; wood; radiation dose; photo-induced color changes; chromophore; natural and artificial irradiation; European wood species; interior; sunlight exposure; physics; chemistry; spectroscopic measurement methods Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-8237 N1 - Version 3 ER - TY - CHAP A1 - Wolff, Ian A1 - Lenz, Claudia A1 - Panitz, Michael A1 - Pfriem, Alexander T1 - Chart for the Core Objectives of Data Publishing within Technical Infrastructure for Research Data Management N2 - Academic data stewardship at universities has to fulfil many different roles. One of the most important is to build up a connection to researchers and bridge the gap between research data infrastructure and researchers. Different scientific communities have different requirements for research data management and expectations regarding text and data publication. In many of the sub-disciplines of engineering sciences, research data management practices are not established so far. When it comes to contact between data stewards and researchers, a common knowledge base has to be established to become clear about why and what actions for research data management has to take, that engineering researchers can adapt them for their research data management practices. Many research data management standards have to take into consideration. However, to this point of time, the research data management community lacks for data literacy graphics to explain how the technical data management ecosystem works together with standards like the findability, accessibility, interoperability and reuse (FAIR) principles. Therefore, we developed a graphic for data literacy and consulting scenarios. KW - data literacy; research data management; engineering sciences; chart Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-8240 ER - TY - GEN A1 - Nölting, Benjamin A1 - Dembski, Nadine A1 - Fritz, Hilke A1 - Kräusche, Kerstin A1 - Lehmann, Kerstin A1 - Molitor, Heike A1 - Pape, Jens A1 - Pfriem, Alexander A1 - Seichter, Cosima Zita A1 - Walk, Heike ED - Hochschule für nachhaltige Entwicklung Eberswalde, T1 - Handreichung: Nachhaltigkeitstransfer in der Lehre BT - Zur Umsetzung von Praxis-Hochschul-Kooperationen im Hochschulalltag N2 - Diese Handreichung knüpft an diese Fragen an: Sie zeigt auf, wie durch Nachhaltigkeitstransfer Lehr-Lern-Prozesse in lebensweltliche Kontexte eingebettet werden können. Transfer findet unserer Erfahrung nach bereits in vielfältiger Form Eingang in die Lehre. Aber häufig fehlen Zeit, Ressourcen und Ansatzpunkte, um Transfer systematisch zu planen, umzusetzen und ihn so zu gestalten, dass er zu nachhaltiger Entwicklung beitragen kann. KW - Nachhaltigkeitstransfer; Transfer; Nachhaltigkeit; Praxis-Hochschul-Kooperationen Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-6414 N1 - Verbundprojektseite: https://www.hochn.uni-hamburg.de/ ER - TY - CHAP A1 - Sanne, Moritz A1 - Kampe, Anja A1 - Lenz, Claudia A1 - Gossel, Stefan A1 - Wagner, Sabine A1 - Haibel, Astrid A1 - Melcher, Eckhard A1 - Leu, Carsten A1 - Pfriem, Alexander A1 - Lautner, Silke ED - Engelund Thybring, Emil T1 - Anatomical studies of wood treated with pressure pulse shock waves T2 - Proceedings of the 13th annual meeting of the Northern European Network for Wood Science and Engineering (WSE2017) N2 - Similar to a normal wave, a shock wave travels as energy through matter but it causes an abrupt raise of pressure, temperature and density. In this study the influence of shock waves on wood structure were investigated in the light of possible future industrial utilization e.g. timber impregnating treatment. KW - shock wave; pressure pulse; impregnation; microtomography Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-6841 ER - TY - CHAP A1 - Lenz, Claudia A1 - Koch, Gerald A1 - Pfriem, Alexander ED - Dresden, IHD T1 - Analyse von bestrahlten, unbehandelten Holzoberflächen mittels UV-Mikrospektralphotometrie (UMSP) T1 - Analysis of irradiated, untreated wood surfaces using UV-microspectrophotometry (UMSP) T2 - Tagungsband 6. Holzanatomisches Kolloquium N2 - Das DFG-Forschungsprojekt „Vorhersagbarkeit der Farbänderungen von Holz im Innenbereich - Die Auswertung in Abhängigkeit von der Strahlungsdosis als neuer Ansatz“ beschäftigt sich mit den Farbveränderungen der Oberflächen von in Mitteleuropa wachsenden Holzarten. Die optischen Eigenschaften des Holzes sind sehr unterschiedlich und im Wesentlichen abhängig von den im Holz vorhandenen chromophoren funktionellen Gruppen (z.B. phenolische Hydroxylgruppen, Doppelbindungen, Carbonylgruppen) und chromophoren Systemen (Chinone, Chinomethide, Biphenyle) (Hon 2001; Rowell et al. 2012). Sowohl zwischen verschiedenen Arten als auch innerhalb einer Holzart gibt es zum Teil erhebliche Farbschwankungen. Eine veränderte Lichtbrechung durch Strukturmerkmale wie Dreh- und Wechseldrehwuchs hat auch Einfluss auf das optische Erscheinungsbild. Farbänderungen treten bereits beim Trocknen oder Dämpfen der Hölzer auf (Aydin und Colakoglu 2005). Zudem verändert sich die Farbe der Oberfläche sowohl beim Auftragen von transparenten Oberflächenbeschichtungen („Anfeuerung des Holzes“) und durch Kombination von beidem. Licht ist der sichtbare (englisch: visible (Vis)) Teil des elektromagnetischen Spektrums, neben weiteren Spektralbereichen wie ultravioletter (UV) und infraroter (IR) Strahlung. UV-, VIS- und IR-Strahlung haben als Teile des Sonnenstrahlungsspektrums eine energetische Wirkung auf Holzoberflächen. Die Farbänderungen bei natürlicher Alterung werden durch Strahlung von UV-, VIS- und IR-Licht und der dadurch induzierten Photooxidation hervorgerufen (Hon und Chang 1982; Feist und Hon 1984; Hon und Minemura 2001). Zur optischen und chemischen Erfassung der Veränderungen der Holzoberflächen wurden in dem Projekt u.a. Farbmessungen im CIE L*a*b*-Farbraum (DIN EN ISO/CIE 11664-4:2020-03), abgeschwächte Totalreflexions-Fourier-Transformations-Infrarot-Spektroskopie (ATR-FTIR) und Spektroskopie im ultraviolett-visuellen Bereich (UV-Vis)sowie regelmäßige Farbscans der Probenoberflächen durchgeführt. Zudem wurden die Methoden der Gaschromatographie mit Massenspektrometrie-Kopplung (GC- MS) und die zelluläre UV-Mikrospektralphotometrie (UMSP) angewandt. Letzte wird im Folgenden näher erläutert. Koch 2004 führte umfangreiche, topochemische Untersuchungen über Inhaltsstoffe im Holzgewebe und deren Bedeutung für die Holzverfärbung durch. Die grundlegenden Untersuchungen zur fakultativen (an Fagus sylvatica L.) und obligatorischen (an Prunus serotina Borkh.)Farbkernbildung beinhaltete die UMSP-Methode. Damit können aromatische Verbindungen in einzelnen Zelltypen und Zellwandschichten hochauflösend, topochemisch detektiert werden. Zudem ist eine qualitative Charakterisierung bzw. Reaktionen von Inhaltsstoffen über UV-Spektren vor und nach einer Sonnenlicht-Simulation möglich. Mit Hilfe der zellulären UV-Mikrospektralphotometrie können aromatische Verbindungen (Lignin, phenolische Extraktstoffe) in einzelnen Zellwandschichten bei einer Auflösung von 0,25 μm x 0,25 μm lokalisiert werden. Die qualitative Charakterisierung von Inhaltsstoffen erfolgt über die Aufnahme von UV/Vis- Spektren im Wellenlängenbereich von 240 bis 700 nm (Messbereich für das UMSP 80, siehe Kapitel 2). Durch das spektroskopische Flächen-Scanning können die Verteilung und semi-quantitative Konzentration von Lignin und phenolischen Extraktstoffen graphisch dargestellt werden (Koch et al. 2003, Koch und Kleist 2001). Vor allem die genaue Visualisierung der farbgebenden Komponenten in den unterschiedlichen Zelltypen und Zellwandschichten sowie deren Änderung durch die Sonnenlicht-Exposition liefert weitere grundlegende Erkenntnisse über die photochemischen Reaktionen im Holzgewebe. Für die chemische Charakterisierung der Stoffe können zudem Punktmessungen mit einer Auflösung von 1 μm² durchgeführt werden. Diese UV/Vis-Extinktionsspektren werden in einem Wellenlängenbereich von 240 bis 580 nm aufgenommen. Ein Absorptionsmaximum im Wellenlängenbereich von 276 bis 280 nm ist z.B. typisch für aromatische und konjugierte Verbindungen. Nach Koch 2004 entstehen mit zunehmender Trocknungstemperatur höherkondensierte Verbindungen, die durch eine starke Verschiebung der Absorptionsmaxima in den längerwelligen Spektralbereich und insgesamt höheren Absorptionswerten charakterisiert werden. Diese Reaktionsmechanismen erklären auch das Farbverhalten des Holzes bei längerer Lichteinstrahlung, durch die ein intensives Nachdunkeln (Lichtalterung) einsetzt. Aufgrund der erheblichen Datensätze von bis zu 60.000 Messpunkten für jedes Scanning-Feld (Größe ca. 50 μm x 50 μm) wird die Auswertung der topochemischen Analysen im Gesamtvorhaben exemplarisch auf drei Holzarten und zwei Schnitttiefen mit vier Messzeitpunkten pro Setup und Behandlung (unbehandelt/extrahiert) reduziert. Die UMSP-Methode findet seither in vielen Bereichen der Holzanalytik Anwendung, z.B. in der Holzbiologie und in der Holzchemie (Andersons et al. 2016, Biziks et al. 2020, Ehmcke et al. 2020, Lewandrowski et al. 2022, Rüggeberg et al. 2008, Schmitt et al., 2015, etc.) KW - Holz KW - Bestrahlung KW - UMSP KW - Alterung KW - Farbänderung Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-8921 SP - 122 EP - 130 CY - Dresden ER - TY - CHAP A1 - Munk, Christoph A1 - Biewer, Raphael A1 - Damay, Jérémie A1 - Jousserand, Michael A1 - Gérardin, Philippe A1 - Pfriem, Alexander T1 - Acoustic properties of thermally treated and furfurylated European hardwood species N2 - Three hardwood species, including alder (Alnus glutinosa), sycamore maple (Acer pseudoplatanus) and hornbeam (Carpinus betulus), were analyzed for changes in their acoustic properties due to thermal treatment (TM), furfurylation (FU) and a combination of both types of treatment (TF). TM was carried out in a nitrogen atmosphere at 200 °C for 4 hours. For FU, a solution of 85% furfuryl alcohol, 10% water and 5% tartaric acid was used, which was impregnated in a vacuum pressure process, followed by polymerization at 120 °C for 16 hours. For each wood species, one test group was left as an untreated reference, the other groups were treated according to the treatment types TM, FU and TF. Per group 10 samples were tested using experimental modal analysis. Due to the orthotropy of the wood, the acoustic parameters dynamic modulus of elasticity (E), damping and sound radiation coefficient were determined in both the longitudinal and radial directions. The results show that TM slightly decreases longitudinal E for all three species and slightly increases radial E for maple and hornbeam. FU and TF strongly increase the E in the radial direction, especially for maple and alder. For all three species the damping is reduced by TM, more in the radial direction than in the longitudinal direction. FU and TF increase the damping in the longitudinal direction, mainly for maple and alder, but also reduce it in the radial direction. The sound radiation coefficient is reduced by FU and TF for all three species, particularly in the longitudinal direction. However, in both the longitudinal and radial directions, TM slightly increases the sound radiation coefficient for all three species. The anisotropy ratio of the longitudinal/radial E of all three species is reduced by FU and TF, whereas TM has no significant effect on it. KW - thermal modification, furfurylation, acoustical properties Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-9864 SP - 1 EP - 3 ER -