Miha Humar

Miha Humar
University of Ljubljana · Biotechnical Faculty, Departement for Wood Science and Technology

PhD

About

239
Publications
56,839
Reads
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2,790
Citations
Citations since 2017
114 Research Items
1886 Citations
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20172018201920202021202220230100200300400
20172018201920202021202220230100200300400
20172018201920202021202220230100200300400
Additional affiliations
October 2020 - October 2022
University of Ljubljana
Position
  • Head of Faculty
October 2016 - October 2019
University of Ljubljana
Position
  • Dean of the Biotechnical Faculty

Publications

Publications (239)
Article
Full-text available
Wood coatings prolong the service life of wood-based products, but they are usually of synthetic origin. The aim of the present article is to reduce the fossil-based compounds in a commercial waterborne acrylic coating by CNC addition and to test its performance. The coatings were applied on European beech and Norway spruce wood in order to test du...
Article
Full-text available
Use of wood products in bio-building is increasing because of the raw material’s sustainability and renewability. Degradation of wood by fungi is one of the most significant threats in the use of wooden structures. In the past, degradation was prevented by the application of wood preservatives or the use of durable tropical species. Therefore, wood...
Article
Full-text available
Citation: Vek, V.; Šmidovnik, T.; Humar, M.; Poljanšek, I.; Oven, P. Comparison of the Content of Extractives in the Bark of the Trunk and the Bark of the Branches of Silver Fir (Abies alba Mill.). Molecules 2023, 28, 225. https://doi.org/10.3390/ molecules28010225 Academic Editor: Francesco Cacciola Abstract: The main objective of our study was to...
Preprint
Full-text available
The coatings on wood must sometimes give aesthetic and basic protection to wooden elements and prevent the development and transmission of microorganisms. Several polymers containing different nanoparticles have already been offered to day for this purpose. A present research presents a novel poly(vinylidene fluoride-co-hexafluoropropylene (PVDF-HF...
Article
The main goal of the investigation was to measure and estimate the thermal stability of pinosylvin, pinosylvin monomethyl ether, robinetin, and dihydrorobinetin, i.e., characteristic compounds of wood of Scots pine and black locust, respectively. The pure compounds were analyzed with chromatography before and after they were steam-sterilized and ov...
Article
Full-text available
Wood in outdoor applications is exposed to various environmental factors that cause weathering. Weathering is important, primarily from an aesthetic standpoint and predominantly in wooden claddings. However, not all parts of claddings are equally exposed to weathering. Sections exposed to UV radiation and moisture discolour faster than less exposed...
Preprint
Use of wood products in bio-building is increasing because of the raw material´s sustainability and renewability. Degradation of wood by fungi is one of the most significant threats in the use of wooden structures. In the past, degradation was prevented by the application of wood preservatives or the use of durable tropical species. Therefore, wood...
Article
Full-text available
This study deals with the biomonitoring of cadmium (Cd) heavy metal in the three selected Tricholoma mushroom species collected from wild habitats of central and coastal Croatia. For this, mushroom (T. columbetta: n = 38, T. portentosum: n = 35, and T. terreum: n = 34) and surface soil samples were collected from nine forest localities of Croatia a...
Article
Characteristics of hawthorn wood concerning soil physicochemical properties were studied. Physical properties such as dry wood density and volumetric swelling and fiber dimension parameters like fiber length, fiber diameter, and cell wall thickness were investigated. Soil properties including clay, silt soil, sand soil, electrical conductivity, pH,...
Conference Paper
Full-text available
This study aimed to evaluate the durability and mechanical properties of two different wood species, namely beech (Fagus sp.) and silver fir (Abies alba), from Bosnia and Herzegovina thermally modified at three different temperatures and duration at maximum temperature. Samples of the mentioned wood species wood (Abies alba) were prepared according...
Article
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The sorption properties of wood have a characteristic influence on some of its properties, such as the mechanical properties and susceptibility to fungal decay. Moist wood is more susceptible to fungal decay, and wood is often impregnated in order to protect it from fungal decomposition, photodegradation or fire. In particular, inorganic salts affe...
Article
Full-text available
In this study, the physical properties (oven-dry density, basic density, volumetric shrinkage, and swelling) and structural components (cellulose, lignin, and extractives content) of three wild almond wood species from southwestern Iran, namely Amygdalus arabica, Amygdalus eburna, and Amygdalus scoparia, were investigated. Wild almond is a valuable...
Article
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The effects of thermal modification of wood have been well established, particularly in terms of reductions in mechanical performance. In recent years, there has been an increase in studies related to the Maillard reaction. More commonly associated with food chemistry, it involves the reaction of amines and reducing sugars during cooking procedures...
Article
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Potato production worldwide is threatened by late blight, caused by the oomycete Phytophthora infestans (Mont.) de Bary. Highly resistant potato cultivars were developed in breeding programs, using resistance gene pyramiding methods. In Sárpo Mira potatoes, five resistance genes (R3a, R3b, R4, Rpi-Smira1, and Rpi-Smira2/R8) are reported, with the l...
Article
Wood in outdoor applications is exposed to various decay factors, of which fungi are the most important. Some wood species are more resistant to fungal decay than others. Forma Viva in Kostanjevica has been exhibiting sculptures made mainly of oak wood for 60 years. The oldest sculpture is the work of Tanaka Eisaku entitled “Japanese Festival”. Aft...
Article
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Purpose Norway spruce log soaking water (SLSW) is considered a waste in the plywood and veneer industry but has not been characterised, and its possible uses remain unexplored. The purpose of this study is to characterise and test the possibility of using SLSW in wood preservative formulations. Methods First, the SLSW was characterised, and the pr...
Article
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The sudden availability of Italian stone pine (Pinus pinea L.) wood due to the infestation of pathogenic fungi and insects highlighted the need to promote its use as a short supply chain resource in Italy and other Mediterranean countries. However, the durability of stone pine sapwood must be enhanced if outdoor use is to be considered. The impregn...
Article
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Wood in outdoor applications is subject to various decomposition factors. Wood degradation can be prevented by construction details, biocide protection of wood, wood modification or selection of naturally durable species. Unfortunately, most species in Europe do not have naturally durable wood. Imported tree species represent a new pool from which...
Article
Interdisciplinary investigations of damaged cultural heritage objects have nowadays become standard practise. Numerous techniques in various fields may generate large amounts of data, difficult to interpret. Machine learning was applied to data collected from samples of a painting to build a predictive model of potential further biodeterioration an...
Article
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The development of non-biocidal and environmentally friendly systems to protect wood against biological decay has become a high priority in recent years. In the present study the impact of an innovative modification procedure, combining two environmentally friendly modification methods: thermal modification and mineralisation, using an aqueous solu...
Article
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Thermal drying is an effective sludge treatment method for dealing with large volumes of sludge. Microwave (MW) technology has been proposed as an effective and efficient technology for sludge drying. The physical-chemical properties of the sludge depend both on the origin of the sludge, as well as on the treatment process at which the sludge has b...
Article
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This study aims to investigate the influence of thermal modification (TM) on the physical and mechanical properties of wood. For this purpose, the experimental part focused on selected influential parameters, namely temperature, residence time, and density, while the four-point bending strength is obtained as the output parameter. The obtained expe...
Article
Construction using timber has seen a resurgence in light of global climate mitigation policies. Wood is a renewable resource, and engineered wood products are proving to be competitive against concrete and steel while having several advantages. However, while the renewable nature of wood in construction is a beneficial property for climate mitigati...
Article
Full-text available
The goal of this research is to investigate some morphological (fibre length, fibre diameter, cell wall thickness, Runkel coefficient, flexibility coefficient, slenderness coefficient, rigidity coefficient, Luce's coefficient, solid coefficient), physical (dry wood density, volumetric shrinkage) and chemical (cellulose, hemicellulose, lignin, ash a...
Article
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One strategy for improving the treatability of refractory wood species is biological incising, and its efficiency depends on how the microorganisms modify the porous structure of the wood. Evaluation of the bioincised wood treatability on a micro-scale can thus help to better understand the treatability enhancing mechanisms. In the present study, t...
Article
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The chemical composition of extractives in the sapwood (SW), heartwood (HW), knotwood (KW), and branchwood (BW of silver fir (Abies alba Mill.) was analyzed, and their antifungal and antioxidant properties were studied. In addition, the variability of extractives content in a centripetal direction, i.e., from the periphery of the stem towards the p...
Conference Paper
Full-text available
The present study aims to investigate the influence of heat treatment on physical and mechanical properties of Oriental beech wood (Fagus orientalis Lipsky.). Samples were exposed to temperature levels of 130˚C, 160˚C, and 190˚C for 3, 6, and 9 h. Selected physical and mechanical properties including compression strength parallel to grain, compress...
Article
Full-text available
Wood is considered the leading building material throughout the history of mankind. Wood has several advantages over other construction materials, which also makes it one of the most promising materials of the future. The environmental aspect also plays a major role today, as wood is a natural, renewable resource whose processing is very energy-int...
Article
Full-text available
The intensity of fungal decay depends mainly on wood species, temperature and precipitation events. To estimate the planned service life of wood and to determine the maintenance intervals of wooden buildings, it is necessary to assess how wood behaves in a given environment. There are a variety of models that have been developed to assess the loadi...
Article
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This study aims at investigating the effect of three altitude levels (below 1800 m, 1800-2000 m and above 2000 m) on the physical and biometric properties of stem-wood and branch-wood of hawthorn species. Moreover, the relationship between wood dry density and volumetric swelling, fiber length, fiber diameter, cell wall thickness were studied. Resu...
Article
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Izvleček / Abstract Izvleček: Les na prostem je izpostavljen delovanju abiotskih in biotskih dejavnikov. Če hočemo njihovo delovanje upočasniti, moramo les zaščititi. V preteklosti je bil biocidni proizvod na osnovi bakrovih, kromovih in borovih spojin (CCB) ena najpomembnejših rešitev za zaščito lesa v ostrih pogojih izpostavitve. Kljub temu, da s...
Article
Full-text available
Les na prostem je izpostavljen delovanju abiotskih in biotskih dejavnikov. Če hočemo njihovo delovanje upočasniti, moramo les zaščititi. V preteklosti je bil biocidni proizvod na osnovi bakrovih, kromovih in borovih spojin (CCB) ena najpomembnejših rešitev za zaščito lesa v ostrih pogojih izpostavitve. Kljub temu, da se CCB v EU praktično ne uporab...
Article
Full-text available
Durability-based designs with timber require reliable information about the wood properties and how they affect its performance under variable exposure conditions. This study aimed at utilizing a material resistance model (Part 2 of this publication) based on a dose–response approach for predicting the relative decay rates in above-ground situation...
Article
Full-text available
Service life planning with timber requires reliable models for quantifying the effects of exposure-related parameters and the material-inherent resistance of wood against biotic agents. The Meyer-Veltrup model was the first attempt to account for inherent protective properties and the wetting ability of wood to quantify resistance of wood in a quan...
Preprint
Full-text available
Citation: Brischke, C.; Alfredsen, G.; Humar, M.; Conti, E.; Cookson, L.; Emmerich, L.; Flaete, P.O.; Fortino, S.; Francis, L.; Hundhausen, U.; et al. Modeling the Material Resistance of Wood-Part 2: Validation and Optimization of the Meyer-Veltrup Model. Forests 2021, 12, 576. https://
Article
Wood is one of the most important building materials. Thermally modified wood is entering the market and replacing wood preservatives and tropical wood species in some applications. Thermally modified wood is exposed to weathering similarly as other wood-based building materials. It has been reported that if thermally modified wood is exposed to we...
Article
Full-text available
To evaluate the performance of new wood-based products, reference wood species with known performances are included in laboratory and field trials. However, different wood species vary in their durability performance, and there will also be a within-species variation. The primary aim of this paper was to compare the material resistance against deca...
Article
Onion production generates abundant waste with high contents of bioactive compounds. These might have several beneficial functional properties for fortification of foods. To understand the variety and potential for further use, we examined various parts of the plants (edible/inedible waste/outer skin of onion), as well as extraction in water/ethano...
Article
Wood is one of the most important building materials. During the service life of wood and derived materials, various degradation factors affect performance. To assess how weathering influenced the material resistance and moisture dynamics of wood, 11 different materials were exposed to natural weathering for 9, 18 and 27 months or artificial accele...
Preprint
Full-text available
The use of wood in outdoor conditions is of great importance for the service life of wood, and the process of thermal modification (TM) directly affects the utility value of wood products. This paper presents theoretical and experimental studies of the parameters influencing TM of the wood on the changes of its physical and mechanical properties. E...
Article
Full-text available
Wood is one of the most important building materials. During the service life of wood and derived materials, various degradation factors affect performance. To assess how weathering influenced the material resistance and moisture dynamics of wood, 11 different materials were exposed to natural weathering for 9, 18 and 27 months or artificial accele...
Article
Full-text available
Wood is considered one of the most important construction materials, as well as a natural material prone to degradation, with fungi being the main reason for wood failure in a temperate climate. Visual inspection of wood or other approaches for monitoring are time-consuming, and the incipient stages of decay are not always visible. Thus, visual dec...
Article
Full-text available
The majority of thermal modification processes are at temperatures greater than 180 ◦C, resulting in a product with some properties enhanced and some diminished (e.g., mechanical properties). However, the durability of thermally modified wood to termite attack is recognised as low. Recent attempts at combining thermal modification with chemical mod...
Article
Full-text available
Buildings on piles have been constructed in Ljubljana since the Bronze Age. The piles were made of different types of wood. In the present study, piles that were erected about 125 years ago were investigated. Investors tend to renovate a building; therefore, the piles were analysed to assess the structural condition of the building. The building sh...
Article
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There are many methods to identify and recognize the molecular and behavioural differences between organisms. One of the methods for the detection and identification of unknown organisms as well as intermolecular and intramolecular structural differences is MALDI-TOF mass spectrometry. Therefore, differentiation of Fomes fomentarius decay capabilit...
Article
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This study investigated the influence of site conditions on the physical and morphological properties of hawthorn wood (Crataegus azarolus L.) grown in Zagros forests of Iran. Hawthorn wood is a valuable woody species in Iran’s Zagros forests with data deficiency in its wood properties. To our best knowledge, there is no study on the properties of...
Article
Full-text available
Wood density is an important physical property that can be easily measured and is closely related to many other wood properties. Furthermore, wood density is a good indicator of the usability and applicability of wood in the wood processing, construction and energy industries. Because it is strongly dependent on moisture content and porosity, there...
Article
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Krožno gospodarstvo in uporaba sekundarnih surovin postajata vedno polj pomembna. Uporaba odsluženega lesa za materialno izrabo je trenutno še zelo slabo izkoriščena. Večino odsluženega lesa se namreč porabi v energetske namene. Eden od potencialnih virov odsluženega lesa so tudi stara lesena okna. Večino oken se v današnjem času zamenja zaradi neu...
Article
Full-text available
Wood ceramics (WCS) were prepared from thermo-modified poplar wood residues and untreated poplar wood. At 1000 °C sintering temperature, the ratios of wood powder and phenolic resin at 10:3, 10:6 and 10:9 were tested. The effects of materials on the properties of WCS, carbon yield and volume shrinkage were studied. With the increase in resin conten...
Article
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The aim of this study was to assess the potential of bacteria Escherichia coli ATCC 35218, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and yeast Pichia membranifaciens ZIM 2417 to adhere to wooden surfaces such as poplar (Populus sp.), Norway spruce (Picea abies), European beech (Fagus sylvatica), beech coated with the comme...
Article
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The main goal of the study was to examine and compare the inhibition effect of knotwood extractives of Scots (Pinus sylvestris) and black pine (Pinus nigra) against the two white-rot fungi and two brown-rot fungi. Knotwood was extracted in a Sox-hlet apparatus. Extracts were chemically analyzed, and the inhibitory effect of purified pinosylvins and...
Article
Full-text available
Research Highlights: The antifungal assay confirmed that knotwood extractives of Scotspine inhibit the growth of wood decay fungi. Heartwood extracts of black locust were found to bemuch stronger free radical scavengers than the extracts of Scots pine. The extracts were depositedin the lumina and on the wall surface of cells in the impregnated sapw...
Article
Full-text available
Persian oak (Quercus brantii Lindl.) is a valuable native species in Iranian forests with very limited availability of data on its wood properties. The objective of the current study was to determine the influence of altitude and slope on physical properties and fiber dimensions of Persian oak wood. In addition, the relationship among wood properti...
Article
Full-text available
The service life of wood in outdoor use under humid conditions is mainly determined by its material resistance and the exposure situation. Different standards such as EN 350 (2016) point on the relevance of wood’s resistance against moisture for its expected service life. Recently, different standardized but also numerous nonstandardized methods we...
Article
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Forests are under great pressure due to climate changes. It is forecast that the importance of Mediterranean type forests will significantly increase. Among various types of oak species, pubescent oak (Quercus pubescens) will likely gain ecological and economic importance in the region south of Alps. Although this wood species is well known, there...
Article
Full-text available
The performance of the composites is influenced by the service life of input raw wood material and used adhesives. The aim of the study was to assess the durability and mechanical performance of glulam beams treated in a different way (thermally modified and/or treated with copper-based wood preservative) and exposed in an outdoor application. Glul...
Article
Full-text available
The violin bridge is an important component of a violin since it transmits the excitation forces from the string to the violin body. Depending on its structure, at a certain frequency spectrum, the bridge acts as a damper or amplifier of excitation forces, which depends on its transfer function. In the study, transfer functions in the range from 40...
Article
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Eutypella parasitica R.W. Davidson & R.C. Lorenz is the causative agent of Eutypella canker of maple, a destructive disease of maples in Europe and North America. The fungus E. parasitica is known to cause wood stain and decay. However, it is not known how effectively it decomposes the wood of the most widespread maple species in Europe. Wood sampl...
Article
Full-text available
The importance of thermal modification is increasing worldwide. Increased use of thermally modified timber (TMT) has resulted in a need for reliable quality control, comprising control of variation of the production within defined limits, allowing third-party control in the case of certification and the regulation of customer complaints and claims....
Article
Full-text available
There is an increasing trend in the use of environmentally-friendly materials in wood protection. This includes the use of less toxic active ingredients, as well as better fixation. This study investigates the formulation based on the combination of copper and Saqez resin on the physical and biological resistance properties of poplar wood. Samples...
Preprint
Full-text available
There is an increasing interest in applying environmentally-friendly materials in wood protection technology. This include the use of less toxic active ingredients, as well as better fixation. This study investigates the formulation based on the combination of copper and Saqez resin on the physical and biological resistance properties of poplar woo...
Experiment Findings
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Article
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In the present study anatomical, histometrical, chemical and physical properties of the wood of 45-year old trees were determined. For this purpose, three trees were randomly cut at Sangdeh-Mazndaran located in the northern part of Iran. Disks and logs were removed at breast height to study the respective wood properties. Fiber length, fiber diamet...