@techreport{BenekenDihFriedetal.2018, author = {Beneken, Gerd and Dih, Denise and Fried, Adrian and Hauch, Julia and Hummel, Sabine and Junker, Elmar and Karlinger, Peter and K{\"o}ster, Heinrich and Krause, Harald and Muscat, Dirk and Niedermaier, Peter and Sch{\"a}fle, Claudia and Schutter, Sabina and Sigr{\"u}ner, Michael and Stanzel, Silke and Str{\"u}bbe, Nicole and Werndl, Peter and Wirnsberger, Markus and Zentgraf, Peter}, title = {Jahresbericht 2018, Forschung - Entwicklung - Innovation}, organization = {Technische Hochschule Rosenheim}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-12374}, pages = {68}, year = {2018}, abstract = {Mit dem j{\"a}hrlich erscheinenden Forschungsbericht m{\"o}chte die Technische Hochschule Rosenheim einen Einblick in ihre vielf{\"a}ltigen Projekte und Aktivit{\"a}ten der angewandten Forschung und Entwicklung geben. Im Jahresbericht 2018 wird {\"u}ber Vorhaben im Jahr 2018 berichtet.}, language = {de} } @techreport{AlversammerAngermeierBernhardtetal.2013, author = {Alversammer, Wolfgang and Angermeier, Martin and Bernhardt, Andreas and Bischof, Wolfgang and Botsch, Rafael and Eierle, Benno and Feldmeier, Franz and Hack, Andreas and Hauck-Bauer, Eva and Heigl, Martin and K{\"o}lzer, Brigitte and K{\"o}ster, Heinrich and Krose, Eva and Leps, Torsten and Mennicken, Titus and Muscat, Dirk and Ober, Thorsten and Ott, Robert and Ruminski, Nils and Seidlmeier, Heinrich and Stauss, Kilian and Stetter, Andrea and Viehhauser, Peter and Wambsganß, Mathias and Zagler, Stefan and Zauner, Johannes and Zentgraf, Peter}, title = {Forschungsbericht 2012}, organization = {Hochschule Rosenheim}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-12338}, pages = {48}, year = {2013}, abstract = {Mit dem j{\"a}hrlich erscheinenden Forschungsbericht m{\"o}chte die Hochschule Rosenheim einen Einblick in ihre vielf{\"a}ltigen Projekte und Aktivit{\"a}ten der angewandten Forschung und Entwicklung geben. Im Forschungsbericht 2012 wird {\"u}ber Vorhaben im Jahr 2012 berichtet.}, language = {de} } @techreport{AckermannAngermeierAueretal.2014, author = {Ackermann, Timo and Angermeier, Martin and Auer, Veronika and Beneken, Gerd and Bernhardt, Andreas and Botsch, Rafael and B{\"u}cker, Dominikus and Hager, Ralf and Hauck-Bauer, Eva and Heigl, Martin and Hirschm{\"u}ller, Sebastian and H{\"o}llm{\"u}ller, Janett and Karlinger, Peter and K{\"o}ster, Heinrich and Krause, Harald and Kucich, Martin and Matthias, Kira and Patzl, Victoria and Pl{\"o}nnigs, Ren{\´e} and Posch, Georg and Schanda, Ulrich and Scheerer, Josua and Schlecht, Johannes and Schmidt, Jochen and Stichler, Markus and Uhl, Cornelius and Viehhauser, Peter and Weber, Gabriel and Wolf, Christopher and Zagler, Stefan and Zentgraf, Peter}, title = {Forschungsbericht 2013}, organization = {Hochschule Rosenheim}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-12324}, pages = {56}, year = {2014}, abstract = {Mit dem j{\"a}hrlich erscheinenden Forschungsbericht m{\"o}chte die Hochschule Rosenheim einen Einblick in ihre vielf{\"a}ltigen Projekte und Aktivit{\"a}ten der angewandten Forschung und Entwicklung geben. Im Forschungsbericht 2013 wird {\"u}ber Vorhaben im Jahr 2013 berichtet.}, language = {de} } @techreport{BauerBeneckenBueckeretal.2015, author = {Bauer, Lucia and Benecken, Gerd and B{\"u}cker, Dominikus and Buff, Alexander and Carlton, Katrina and Feldmeier, Franz and Flatscher, Simon and Hack, Andreas and Halt, Manfred and Jell, Peter and K{\"o}ster, Heinrich and Kucich, Martin and Manzinger, Franziska and Mecking, Simon and Paus, Inger and Rex, Steffen and Schanda, Ulrich and Schreyer, Manuela and Spindler, Uli and Stadler, Constanze and Stahnke, Svenja and Stiegler, Gertrud and Walser, Georg and Wambsganß, Mathias and Wellisch, Ulrich}, title = {Forschungsbericht 2014}, organization = {Hochschule Rosenheim}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-12317}, pages = {68}, year = {2015}, abstract = {Mit dem j{\"a}hrlich erscheinenden Forschungsbericht m{\"o}chte die Hochschule Rosenheim einen Einblick in ihre vielf{\"a}ltigen Projekte und Aktivit{\"a}ten der angewandten Forschung und Entwicklung geben. Im Forschungsbericht 2014 wird {\"u}ber Vorhaben im Jahr 2014 berichtet.}, language = {de} } @techreport{BarthBeneckenBetzetal.2016, author = {Barth, Simon and Benecken, Gerd and Betz, Andreas and Binninger, Karsten and Graule, Verena and Hack, Andreas and Haegele, Rainer and Hartmann, Markus and Hauck-Bauer, Eva and Haut, Sandra and J{\"a}ger, Johannes and Kagerl, Andreas and Karlinger, Peter and Konle, Elke and K{\"o}ster, Heinrich and Krause, Harald and Krommes, Sandra and Meissner, Thomas and Michanickl, Andreas and Sandor, Viktor and Schanda, Ulrich and Schemme, Michael and Sebald, Daniela and Spindler, Uli and Stauss, Kilian and Strobl, Thomas and Sussmann, Monika and Versen, Martin and Voit, Johann and Wambsganß, Mathias and Wellisch, Ulrich and Zauner, Johannes}, title = {Forschungsbericht 2015}, organization = {Hochschule Rosenheim}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-12304}, pages = {76}, year = {2016}, abstract = {Mit dem j{\"a}hrlich erscheinenden Forschungsbericht m{\"o}chte die Hochschule Rosenheim einen Einblick in ihre vielf{\"a}ltigen Projekte und Aktivit{\"a}ten der angewandten Forschung und Entwicklung geben. Im Forschungsbericht 2015 wird {\"u}ber Vorhaben im Jahr 2015 berichtet.}, language = {de} } @techreport{AuerBenekenBrummeretal.2017, author = {Auer, Veronika and Beneken, Gerd and Brummer, Benjamin and Ch{\^a}teauvieux-Hellwig, Camille and Engler, Benjamin and Gilly, Alexander and Hagl, Rainer and Hummel, Felix and Hummel, Sabine and Karlinger, Peter and Knorr, Ludwig and K{\"o}ster, Heinrich and Kucich, Martin and Mecking, Simon and Rabold, Andreas and Sandor, Viktor and Schalk, Daniel and Schanda, Ulrich and Schemme, Michael and Schiffner, Ivonne and Schmidt, Jochen and Schugmann, Reinhard and Seidlmeier, Heinrich and Sigg, Ferdinand and Stauss, Kilian and Sussmann, Monika and Wellisch, Ulrich and Wenninger, Marc and Wittmann, Josef and Zscheile, Matthias}, title = {Jahresbericht 2016, Forschung - Entwicklung - Innovation}, organization = {Hochschule Rosenheim}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-12282}, pages = {68}, year = {2017}, abstract = {Mit dem j{\"a}hrlich erscheinenden Forschungsbericht m{\"o}chte die Hochschule Rosenheim einen Einblick in ihre vielf{\"a}ltigen Projekte und Aktivit{\"a}ten der angewandten Forschung und Entwicklung geben. Im Jahresbericht 2016 wird {\"u}ber Vorhaben im Jahr 2016 berichtet.}, language = {de} } @techreport{AckermannHauckBauerJaegeretal.2018, author = {Ackermann, Timo and Hauck-Bauer, Eva and J{\"a}ger, Johannes and K{\"o}ster, Heinrich and Krause, Harald and Mayr, Wolfgang and Mysliwetz, Birger and Niedermaier, Peter and Ober, Thorsten and Pfaffenberger, Ulrich and Stauss, Kilian and Werndl, Peter and Zscheile, Matthias}, title = {Jahresbericht 2017, Forschung - Entwicklung - Innovation}, organization = {Hochschule Rosenheim}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-12278}, pages = {68}, year = {2018}, abstract = {Mit dem j{\"a}hrlich erscheinenden Forschungsbericht m{\"o}chte die Hochschule Rosenheim einen Einblick in ihre vielf{\"a}ltigen Projekte und Aktivit{\"a}ten der angewandten Forschung und Entwicklung geben. Im Jahresbericht 2017 wird {\"u}ber Vorhaben im Jahr 2017 berichtet.}, language = {de} } @article{ObermeierSchumacherBarthetal.2020, author = {Obermeier, Frederik and Schumacher, Mara and Barth, Simon and Karlinger, Peter and Schemme, Michael and Michanickl, Andreas}, title = {Thermoplastische Hybridverbunde mit Holzfasern - Leichtbau mit Naturfasern}, series = {Plastverarbeiter}, volume = {2020}, journal = {Plastverarbeiter}, number = {2}, publisher = {H{\"u}thig GmbH}, address = {Heidelberg}, pages = {34-36}, year = {2020}, abstract = {Gewichtsreduktion ist eine der entscheidenden Herausforderungen, um nachhaltige Fahrzeuge zu entwickeln. Der Einsatz von nachwachsenden Rohstoffen in Form von Naturfasern, wie Flachs, Kenaf, Hanf, ist Stand der Technik und findet vor allem in der Automobilindustrie Anwendung. Die Gr{\"u}nde sind zahlreich. Naturfasern sind wesentlich kosteng{\"u}nstiger als Carbonfasern und leichter als Glasfasern. Dadurch ergeben sich Kosten- und Gewichtsvorteile. Es lassen sich zudem hervorragende mechanische Eigenschaften erzielen. Schließlich bietet die Verwendung von Naturfasern einen deutlichen {\"o}kologischen Vorteil. H{\"a}ufig kommen dabei Hybridverbunde zum Einsatz. Durch Hybridverbunde lassen sich die Vorteile von Spritzguss und Pressverfahren kombinieren (Funktionalisierung bei hoher Eigensteifigkeit).}, language = {de} } @inproceedings{ObermeierSchumacherBarthetal.2019, author = {Obermeier, Frederik and Schumacher, Mara and Barth, Simon and Karlinger, Peter and Schemme, Michael and Michanickl, Andreas}, title = {Thermoplastische Holzfaservliese f{\"u}r Hybridverbunde}, series = {13. Holzwerkstoffkolloqium}, booktitle = {13. Holzwerkstoffkolloqium}, publisher = {Institut f{\"u}r Holztechnologie Dresden gemeinn{\"u}tzige GmbH}, address = {Dresden}, pages = {66 -- 67}, year = {2019}, abstract = {Leichtbau und Ressourcenschonung sind zentrale Themen des 21. Jahrhunderts. Hybridverbunde mit Naturfasern (z.B. Flachs, Kenaf) sind Stand der Technik und werden v.a. im Automobilbau verwendet. Durch Hybridverbunde lassen sich die Vorteile von Spritzguss und Pressverfahren kombinieren (Funktionalisierung bei hoher Eigensteifigkeit). Obwohl Holzfasern diverse Vorteile gegen{\"u}ber Naturfasern bieten (z.B. geringere Rohstoffrisiken), sind sie in diesem Bereich noch nicht umfassend untersucht.}, language = {de} } @inproceedings{ObermeierSchumacherBarthetal.2019, author = {Obermeier, Frederik and Schumacher, Mara and Barth, Simon and Karlinger, Peter and Schemme, Michael and Michanickl, Andreas}, title = {Thermoplastische Hybridverbunde mit Holzfaserverst{\"a}rkung}, series = {Technomer 2019}, booktitle = {Technomer 2019}, publisher = {Technomer 2019}, address = {Technische Universit{\"a}t Chemnitz}, pages = {11}, year = {2019}, abstract = {Leichtbau und ressourcenschonende Herstellungstechnologien sind zentrale Themen des 21. Jahrhunderts. Thermoplastische Hybridverbunde mit endlosfaserverst{\"a}rkten Einlegern spielen dabei eine große Rolle, sogenannte Organobleche. Auch Hybridverbunde mit Naturfaserverst{\"a}rkung sind seit langem Stand der Technik und werden vor allem in der Automobilindustrie verwendet. Holzfasern sind in diesem Bereich jedoch noch nicht umfassend untersucht. Der Vortrag befasst sich mit dem Potenzial von Holzfasern f{\"u}r thermoplastische Hybridverbunde im Vergleich zu Naturfasern. Dabei wird ein Einblick auf prozess- und materialtechnische Untersuchungen gegeben. Bei den Versuchen kommen diverse Technologien zum Einsatz. Holzfasern werden {\"u}ber ein Air-Lay-Verfahren mit Kunststofffasern zu einem Vlies gelegt. Bei der Weiterverarbeitung der konsolidierten Vliese zu Hybridverbunden, werden diese mit direkt compoundierten Holzfasern {\"u}ber einen In-Mould-Compounder angespritzt. Es zeigt sich, dass Faserverbunde mit Holzfasern vielversprechende Eigenschaften haben. Weitere Untersuchungen sind n{\"o}tig, um ein tiefgreifendes Verst{\"a}ndnis f{\"u}r die Werkstoffe und die Prozesse zu entwickeln.}, language = {de} } @inproceedings{SchemmeDittmarKarlingeretal.2019, author = {Schemme, Michael and Dittmar, Harri and Karlinger, Peter and Hummel, Sabine}, title = {Closed-Loop-Recycling - Strategien f{\"u}r endlosfaserverst{\"a}rkte thermoplastische Hybridstrukturen (Vortrag)}, series = {FOREL Kolloquium}, booktitle = {FOREL Kolloquium}, year = {2019}, language = {de} } @article{HummelSchemmeKarlinger2019, author = {Hummel, Sabine and Schemme, Micheal and Karlinger, Peter}, title = {GmbH - Glasfaserhybride mit bester Haftung: Variotherme Temperierung f{\"u}r Organobleche}, series = {Plastverarbeiter}, volume = {07/2019}, journal = {Plastverarbeiter}, number = {07}, publisher = {H{\"u}thig GmbH}, address = {Heidelberg}, pages = {2}, year = {2019}, abstract = {Durch Integrieren der Variothermie k{\"o}nnen Organobleche wirtschaftlich und technisch verbessert zu Hybridbauteilen verarbeitet werden. Somit steigert sich der Wettbewerbsvorteil gegen{\"u}ber konventionellen Werkstoffen weiter. An einer Technische Hochschule wird seit mehr als zehn Jahren intensiv an der Thematik der Verbindungstechnologien sowie den Haftungsmechanismen zwischen endlosfaserverst{\"a}rkten Thermoplasten, den sogenannten Organoblechen, und angespritzten Funktionsstrukturen geforscht. Im Fokus stehen prozesstechnische Einfl{\"u}sse, die die Verbundhaftung der Hybridleichtbaustrukturen erh{\"o}hen.}, language = {de} } @article{HirschmuellerPravidaMarteetal.2019, author = {Hirschm{\"u}ller, Sebastian and Pravida, Johann and Marte, Roman and Flach, Michael}, title = {Long-term material properties of circular hollow laminated veneer lumber sections under water saturation and cement alkaline attack}, series = {Wood Material Science and Engineering}, volume = {14}, journal = {Wood Material Science and Engineering}, number = {3}, pages = {142 -- 156}, year = {2019}, abstract = {Innovative beech laminated veneer lumber (LVL) circular hollow sections for the use as temporary geotechnical soil nailing systems are currently being developed. Due to the permanent subsoil cement embedment, combined with high water saturation and permanent loading, the timber sections will lose strength and stiffness over time to a degree currently unknown. This paper presents the tensile and bending material properties of flat and curved beech LVL under various periods of immersion in a water-cement grout solution aiming at inducing both water saturation and long-term alkaline attack of the timber. In total, 824 and 279 samples were tested in tension and bending, respectively. Results show that samples manufactured from 3 mm thick veneers result in tensile strength and stiffness 17\% and 24\% higher, respectively, than samples manufactured from 2 mm thick veneers. A reduction in the initial bending and tensile strength of up to 70\% was found after 90 days of water saturation and cement contact. Taking into account a duration of load factor for permanent loading of two years, it is recommended to reduce the short-term tensile and bending strength of beech circular hollow sections to be used as geotechnical anchors by 80\%.}, language = {en} } @inproceedings{MonsbergerLienhartMarteetal.2018, author = {Monsberger, Christoph and Lienhart, Werner and Marte, Roman and Hirschm{\"u}ller, Sebastian}, title = {Monitoring of soil nailed slope stabilizations using distributed fiber optic sensing}, series = {Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2018}, volume = {10598}, booktitle = {Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2018}, editor = {Sohn, Hoon}, doi = {10.1117/12.2296674}, year = {2018}, abstract = {Soil nailing systems are a common way to stabilize slopes and construction pits. Their design is usually based on the mechanical equilibrium of a rigid body motion and therefore, only tensile stresses are considered and accompanying forces like bending (shear stresses) in the soil nails are neglected. Continuous strain measurements along nails could verify this assumption, but may not be performed using conventional sensing technologies. This paper reports about monitoring of a soil nailed slope stabilization using distributed fiber optic sensing. Soil nails in different anchoring horizons were instrumented and autonomously monitored over several weeks, in which the construction pit was excavated continuously. After the excavation, the final load bearing capacity of one selected nail was determined within a classical geotechnical load test. In addition to the field measurements, the bending behavior of the instrumented nail system was analyzed under laboratory conditions. The presented studies demonstrate the high potential of distributed fiber optic sensing systems and their capability to extend traditional measurement methods in foundation engineering applications.}, language = {en} } @article{HirschmuellerPravidaMarteetal.2018, author = {Hirschm{\"u}ller, Sebastian and Pravida, Johann and Marte, Roman and Flach, Michael}, title = {Adhesive properties of laminated veneer lumber poles for use in temporary soil nailing: development and evaluation of a test method for curved structures in a high-alkaline environment}, series = {Wood Science and Technology}, volume = {52}, journal = {Wood Science and Technology}, number = {4}, editor = {Springer,}, pages = {1061 -- 1092}, year = {2018}, abstract = {Innovative circular, hollow, laminated veneer lumber (LVL) beech sections for use as temporary geotechnical soil reinforcement members are currently being developed. Appropriate surface gluing quality between the veneers is fundamental to this subsoil application of the permanently cement-embedded, engineered timber product. The circular cross-section geometry and the permanently high-alkaline environment of the structural member is not covered by presently standardized testing and conditioning methods for examining LVL surface bond line quality. The sample conditioning and tensile shear test method compliant with EN 302-1 (Adhesives for load-bearing timber structures—test methods—part 1: determination of longitudinal tensile shear strength, European Committee for Standardization, Brussels, 2013) was modified to determine bonding parameters for circular, hollow LVL sections. Bond line curvature, groove cutting depth and sample geometry were found to greatly influence stress distribution, percentage of wood failure and tensile shear strength. Short-term alkaline treatment of test samples did not significantly influence the bonding performance, wood failure percentage, tensile shear strength and fracture patterns. To improve tensile shear strength, adhesives with different material rigidities were used and compared. An orthotropic, elastic numerical analysis revealed a greater influence of adherent elasticity than adhesive elasticity on the stress distribution within the bond line. With regard to determining the bond line integrity of curved veneer poles, a sample geometry compliant with EN 302-1 (2013) was developed and numerically evaluated.}, language = {en} } @inproceedings{HirschmuellerMartePravida2016, author = {Hirschm{\"u}ller, Sebastian and Marte, Roman and Pravida, Johann}, title = {Laminated veneer lumber poles for temporary soil nailing - investigation of material properties}, series = {Proceedings of the World Conference on Timber Engineering. World Conference on Timber Engineering. Vienna, 22.-25.08. Vienna}, booktitle = {Proceedings of the World Conference on Timber Engineering. World Conference on Timber Engineering. Vienna, 22.-25.08. Vienna}, editor = {Eberhardsteiner, Josef and Winter, Wolfgang and Fadai, A. and P{\"o}ll, Martha}, year = {2016}, abstract = {Within a current research project at Rosenheim University of Applied Sciences and Graz University of Technology the possibilities of using beech wood laminated veneer lumber poles as soil anchors for temporary soil nailing systems are investigated. Therefore tensile and bending properties of laminated veneers with high moisture and permanent cement contact concerning the influence of veneer bending rectangular to the fibre are determined. For investigation of material properties under different climate conditions tensile tests on small and faultless single beech wood veneers as well as tensile tests on 6 layered 3 mm samples and 9 layered 2 mm samples were carried out. Therefore all samples were stored in extreme climate conditions like high moisture content and permanent cement contact. Six layered samples with 3mm thick veneers show a slightly higher strength and stiffness under dry conditions as well as at a moisture content of the samples above fibre saturation. A strength reduction factor concerning temporary geotechnical applications is suggested which considers the influence of long term loading, veneer bending, water saturation and cement destruction on tensile properties of laminated veneer lumber poles.}, language = {en} } @article{HirschmuellerMartePravidaetal.2018, author = {Hirschm{\"u}ller, Sebastian and Marte, Roman and Pravida, Johann and Flach, Michael}, title = {Inhibited wood degradation of cement-coated beech Laminated Veneer Lumber (LVL) for temporary in-ground applications.}, series = {European Journal of Wood and Wood Products}, volume = {76}, journal = {European Journal of Wood and Wood Products}, number = {5}, editor = {Springer,}, pages = {1483 -- 1494}, year = {2018}, abstract = {This paper investigates the long-term tensile properties of laminated veneer lumber (LVL) beech sections coated with cement and exposed to fungal decay. A set of LVL coupon (dog-bone) samples was stored in compost, tested in tension after 6 and 12 months and compared to reference samples stored at 20 °C and 65\% relative humidity. Results showed that after 26 weeks of compost exposure, a fungus of the Ascomycota genus was identified in cement-coated samples using a molecular biology polymerase chain reaction (PCR) technique, which analyses the internal transcribed spacer (ITS) region of the ribosomal DNA. However, no visual deterioration was noticed. Still in cement-covered samples and after 12 months of exposure, a common white rot fungus was determined by DNA chip technology, but no fungal wood decay was visible in areas where the applied coating had a thickness of at least 5 mm. Decay in uncoated LVL samples was significant with the samples having an average residual strength equal to 7\%. This compares to the tensile strength of coated samples, which only decreased by 65\% relative to the reference samples. Strength and stiffness of coated samples did not differ significantly between 6 and 12 months of exposure. Preliminary investigations tend to show that the strength reduction in cement-coated samples is due to an alkaline degradation of the wood. The observed influence of the coating thickness on the visual fungal decay can probably be ascribed to the protection mechanism due to a physical fungal barrier with a high pH.}, language = {en} } @inproceedings{HirschmuellerPravidaMarteetal.2016, author = {Hirschm{\"u}ller, Sebastian and Pravida, Johann and Marte, Roman and Flach, Michael}, title = {Laminated veneer lumber poles for use in temporary soil nailing. Investigation of adhesive properties.}, series = {Holzbau Forschung und Praxis. 6. Doktorandenkolloqium 2016}, booktitle = {Holzbau Forschung und Praxis. 6. Doktorandenkolloqium 2016}, editor = {Universit{\"a}t Stuttgart,}, year = {2016}, abstract = {Within a current research-project the possibility of using laminated veneer lumber beech wood poles as temporary soil anchors in foundation engineering is investigated. Within this project adhesive properties of laminated veneer lumber beech wood poles are determined. For use in temporary ground applications the influence of veneer bending, veneer thickness and intensive cement contact is concerned. As standard version two different adhesive systemsmelamine formaldehyde resin (MUF) and a 1-component polyurethane adhesive (PUR) were investigated and compared. Melamine formaldehyde resin glued samples with 3 mm thick veneers and 1.0N/mm² press force show a higher tensile shear strength but also a higher adhesive failure percentage than polyurethane glued samples. In case of melamine formaldehyde resins the closed time has a great influence on bond line quality. A long closed time reveals a low penetration of adhesive in the cells and a low embedding on the wood surface. For curved structures best results were achieved with a bonding pressure of 1.0 N/mm². A significant difference in strength between the concerned MUF and PUR adhesive system was not recognized.}, language = {en} } @article{HirschmuellerPravidaMarteetal.2018, author = {Hirschm{\"u}ller, Sebastian and Pravida, Johann and Marte, Roman and Flach, Michael}, title = {Adhesive properties of laminated veneer lumber poles for use in temporary soil nailing: bonding performance of curved structures in a high-alkaline environment}, series = {Wood Science and Technology}, volume = {52}, journal = {Wood Science and Technology}, number = {5}, editor = {Springer,}, pages = {1289 -- 1311}, year = {2018}, abstract = {Circular hollow sections of beech-laminated veneer lumber (LVL) for the use as temporary geotechnical soil nailing systems are currently being developed. Due to their permanent subsoil cement embedment, investigations of the bond line quality of the timber sections are essential. This paper presents the bonding properties of flat and curved beech LVL after cyclic conditioning in a water-cement grout solution aimed at inducing short- and long-term alkaline attack of the timber. In total, 409 and 69 samples were tested in tensile shear tests after short-term and long-term conditioning, respectively. Three different adhesive systems, a one-component polyurethane adhesive, a melamine-urea-formaldehyde adhesive and a melamine-urea-formaldehyde adhesive modified by means of (polyvinyl)-acetate adhesive were investigated and compared. Short-term conditioning by submersion in boiling cement suspension was found to be a reliable method for testing the bonding performance rather than long-term conditioning. In the case of tensile shear tests of samples subjected to long-term treatment, wood material strength was the decisive criterion. Generally, tensile shear test samples of all investigated adhesives achieved reliable bonding for a pressing force up to 1.0 MPa. No relationship was recognised between the determined bonding failure and the wood properties tensile shear strength, wood failure percentage, fracture pattern and bulk density of veneers adjacent to the bond line. For the determination of the bond line integrity of curved veneer poles, it was necessary to test bonding quality in a combined test using curved and flat samples and to compare tensile shear strength with data determined on reference samples in the same veneer population without bond line.}, language = {en} } @article{WentzkyTittelJaegeretal.2018, author = {Wentzky, V. C. and Tittel, J. and J{\"a}ger, Christoph G. and Rinke, K.}, title = {Mechanisms preventing a decrease in phytoplankton biomass after phosphorus reductions in a German drinking water reservoir—results from more than 50 years of observation}, series = {Freshwater Biology}, volume = {63}, journal = {Freshwater Biology}, number = {9}, editor = {Wiley,}, pages = {1063 -- 1076}, year = {2018}, abstract = {1. To counteract the severe consequences of eutrophication on water quality and ecosystem health, nutrient inputs have been reduced in many lakes and reservoirs during the last decades. Contrary to expectations, in some lakes phytoplankton biomass did not decrease in response to oligotrophication (nutrient reduction). The underlying mechanisms preventing a decrease in biomass in these lakes are the subject of ongoing discussion. 2. We used a hitherto unpublished long-term data set ranging from 1961 until 2016 from a German drinking water reservoir (Rappbode Reservoir) to investigate the underlying mechanisms preventing a decrease in biomass. Total phosphorus (TP) concentrations in the Rappbode Reservoir dropped abruptly in 1990 from 0.163 to 0.027 mg/L within three consecutive years, as a result of banning phosphate-containing detergents. Despite substantial reductions in TP, total annual phytoplankton biomass did not decline in the long-run, and therefore, the yield of total phytoplankton biomass per unit phosphorus largely increased. 3. Regression analysis revealed a positive association between the yield and potentially phagotrophic mixotrophs (R2 = .465, p < .001). We infer that by ingesting bacteria, mixotrophic species were capable of exploiting additional P sources that are not accessible to obligate autotrophic phytoplankton, eventually preventing a decrease in algal biomass after TP reductions. 4. Long-term epilimnetic phosphorus concentrations during the winter mixing period decreased to a greater degree than summer phosphorus concentrations. Apparently, TP losses over the season were less intense. Spring diatom biomass also markedly decreased after oligotrophication. In fact, spring diatom biomass was positively related to the TP loss over the season suggesting diatoms play an important role in P reduction. However, this intraannual P processing was not the primary factor when focusing on the average yearly yield, which remained to be fully explained by mixotrophs. 5. Our study demonstrates this ecosystem's ability to compensate for changes in resource availability through changes in phytoplankton community composition and functional strategies. We conclude that an increase in mixotrophy and the ability to make bacterial phosphorus available for phytoplankters were the main factors that allowed the phytoplankton community of the Rappbode Reservoir to adapt to lower nutrient levels without a loss in total biomass.}, language = {en} }