Zoltán Pásztory

Zoltán Pásztory
University of West Hungary, Sopron · Faculty of Wood Sciences

About

78
Publications
22,287
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598
Citations
Citations since 2016
61 Research Items
562 Citations
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200

Publications

Publications (78)
Article
This study presents the experimental results of thermal conductivity measurements for samples made from coir fibers at three different densities over the range of mean temperature from 10° to 40 °C. Data showed the dry thermal conductivity values at a mean temperature of 15 °C are 0.04 (W/m·K), 0.046 (W/m·K), and 0.0522 (W/m·K) which are lower than...
Conference Paper
The purpose of this paper is to experimentally study the thermal resistance values (RSI values) of building insulation materials made mainly from natural fibers. Natural fibrous materials or renewable resources and their reinforcement composites are currently being used in building and construction as a potential solution to significantly reduce th...
Article
Full-text available
Environment friendly insulation panels were manufactured and tested made of pine wood fibers and glued with a bio-polymer, called dextran. The aim of this work was to determine relevant technical properties of panels fabricated with this new glue type. In the panels, the ratio of dry glue content was varied from 30% to 60% with 10% steps which runs...
Article
The utilization of rubberwood (Hevea brasiliensis) and coconut wood (Cocos nucifera L.), the essential economic crops in Thailand and tropical countries, was proposed for manufacturing mixed species/density cross-laminated timber (CLT) for building construction. Six 3-layer CLT configurations, which are composed of either medium-density (600 – 799...
Article
Full-text available
This paper presents a thermal characterization of hardwoods of Hungarian origin. The study covers the wood of the following tree species: sessile oak (Quercus petraea), beech (Fagus sylvatica), hornbeam (Carpinus betulus), black locust (Robinia pseudoacacia), lime (Tilia platyphyllos), ash (Fraxinus ornus), maple (Acer campestre), alder (Alnus glut...
Article
Hygroscopic properties of nine hardwoods from Hungary were studied by moisture sorption isotherms, methods of thermogravimetry (TG) and differential scanning calorimetry (DSC). The studied wood species included oak, beech, hornbeam, black locust, lime, ash, maple, alder, and aspen. The parameters of the wood — water sorption system were calculated...
Chapter
Water pollution is a pressing issue due to growing levels of industrialization and increasing amounts of domestic wastewater. The possibility of harvesting energy from waste has captured the attention of the scientists across the globe. In this regard, the membrane-less microbial fuel cell (ML-MFC) has come across as a sustainable choice of technol...
Article
This study focuses on trade of hardwood products in selected countries of Eastern Europe, specifically the Czech Republic, Slovakia, and Hungary. It was supported by a survey conducted with companies producing products made of hardwoods. It monitors trade trends in the wood products industry, specifically focusing on lumber, wooden veneers, furnitu...
Article
Full-text available
The fundamental material properties of coconut wood cross-laminated timber (CLT) were experimentally evaluated with a focus on the effect of the lamination density. Considering the significant density variations across the coconut trunks, the CLT specimens were manufactured using the coconut wood laminations of four density ranges: 655 ± 31 kg/m³,...
Article
Full-text available
The suitabilities of major agricultural residues were assessed as papermaking feedstocks. All the examined agricultural residues were assumed as potential candidates for substituting hardwood fibers in mixed pulp blends from a fiber morphological perspective. Wheat, barley, rice, rapeseed, maize, sunflower, sugarcane bagasse, coconut husk, and two...
Article
Full-text available
This study is a comparative investigation of antioxidant and antibacterial properties of tree bark extracts of three common European species, Prunus avium L., Larix decidua Mill. and C astanea sativa Mill. The bioactive compounds present in the bark were recovered in 80% aqueous ethanol using ultrasound as the green extraction method. The antioxida...
Article
The present study explored the use of chitosan films functionalized with antioxidants extracted from Larix decidua Mill. bark for active packaging. The pristine chitosan and extract-incorporated chitosan films were evaluated for their structural, physico-mechanical, thermal, viscoelastic and antioxidant properties using advanced characterization te...
Article
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This article aims to provide a fundamental understanding of different building insulation materials and their thermal conductivities. The main research question is to discuss the factors influencing thermal conductivity coefficients of insulation materials used in building envelopes. Another object is to synthesize the relationship between mean tem...
Article
Full-text available
The lignin, cellulose and hemicelluloses in wood are polymers that behave similarly to the artificial polymers and are bonded together in wood. Lignin differs from the other two substances by its highly branched, amorphous, three-dimensional structure. Under appropriate conditions, the moist lignin incorporated in the wood softens at about 100 °C a...
Article
Full-text available
One way of satisfying increased market demand and simultaneously achieving a reduced environmental load in the industrial paper production is the use of fibrous agricultural residues. The aims of this study were i) to investigate the effect of alkaline – hydrodynamic cavitation (HC) pre-treatments on the delignification of Miscanthus x giganteus st...
Article
Natural insulations made from by-products available in large quantities are growing in importance. In the wood processing industry, among other materials, wood chips and shavings are available in large quantities. The aim of this research was to determine the optimal density of thermal insulation panels made of different wood shavings. Planer and d...
Article
Poplar (Populus x euramericana cv. pannonia) samples were irradiated using ultraviolet light emitter mercury lamp. Other series of specimens were treated with the combination of UV radiation and water leaching. The total duration of UV radiation for both series of specimens was 20 days. The total duration of water leaching was 10 days. One cycle of...
Article
Formaldehyde in the indoor air is one of the chemicals which can cause health risk; therefore, researchers have strived to reduce formaldehyde emissions from different wood products. There are many chemical compounds in bark, including tannins, which can react with formaldehyde. The aim of this study was to reduce the formaldehyde emissions from HD...
Article
Full-text available
The present work evaluates and compares the antioxidant capacities of bioactive constituents in the barks of ten common wood species from Hungary (Quercus rubra, Prunus serotina, Quercus robur, Betula pendula, Fraxinus excelsior, Robinia pseudoacacia, Carpinus betulus, Picea abies, Alnus glutinosa, Pinus sylvestris). Low-frequency ultrasound was us...
Article
Full-text available
Black locust (Robinia pseudoacacia L.), beech (Fagus sylvatica L.), aspen (Populus tremula L.) and sessile oak (Quercus petraea Liebl.) hardwood samples were irradiated by a strong ultraviolet (UV) emitter mercury lamp at 50 °C. Other series of specimens were exposed to a combined treatment of UV irradiation and water leaching. Ratio of UV radiatio...
Article
Full-text available
The tree bark has been used by mankind for centuries in various ways. The bark has special structure and chemical components, and it is used mostly among the natural raw materials. The bark has numerous functions during the lifespan of the plant, while itself is also changing due to its age. The outer bark is very diverse, depending on the species,...
Article
Full-text available
This study was carried out to assess the feasibility of glass fibres of various lengths (12 mm, 18 mm, 24 mm and 30 mm) as reinforcement on the mechanical performance of bark particleboards intended for thermal insulation. To evaluate their efficiency, the results of fibre reinforced particleboards at mass of 3wt% concentration were compared with p...
Article
This study examined the use of Plantago psyllium seed husk flour as paper additive with the aim of improving the properties of cellulose sheet. The husk flour was added in 5 wt%, 10 wt%, 20 wt% and 30 wt% to the cellulose suspensions and its effect on the handsheet properties was studied. The results showed that the direct addition of husk flour hi...
Article
The color variance of dry coconut wood and its relationship with the wood density was explored. Coconut trunks with two different ages of 30 and 60 years old were selected for the experiment. Wood color was measured by the CIE L*a*b* or CIELAB color system on both the transverse (longitudinal-tangential plane) and cross (tangential-radial plane) se...
Article
Finger-joint is a technological process that uses small-dimension and low-quality lumber to obtain high-quality structural wood products. Curing time of an adhesive consists one of the most important factors on the final performance of finger-jointed wood. In this study, finger-jointed black pine (Pinus nigra L.) specimens were prepared to investig...
Article
Full-text available
Features and characteristics of wood as a natural smart material allow us to use it to create new smart biocomposite materials, intelligent systems and environments. The shape-memory effect of oak (Quercus robur L.) and birch (Betula pendula Roth) veneers was investigated. Thermomechanical spectrometry was used to study these two species, which mak...
Article
Full-text available
The thermal conductivity properties of wood of Paulownia Clones in Vitro 112 were investigated after heat treatment at temperatures of 180 °C, 200 °C and 220 °C. After the treatment, the density decreased by 5.6, 8.9, and 14.1% for the samples heat-treated at 180 °C, 200 °C and 220 °C, respectively. The decrease in the thermal conductivity was 0, 2...
Article
Kutatásunk célja a különböző időtartamú hőkezelés és néhány fizikai, valamint a hővezetési tulajdonságok közötti összefüggések detektálása. A vizsgálatok során lucfenyő (Picea abies), Pannónia nyár (Populus × euramericana cv. Pannónia) és gumifa (Hevea brasiliensis) faanyagot 180 °C-on 15, 25 és 35 órás hőkezelésnek vetettünk alá. Méréseink igazolt...
Article
Számos kutatás foglalkozik természetes anyagokból készül szigetelő anyagokkal, közöttük a kéreggel is. A kéregből készült lemezek fizikai és mechanikai tulajdonságai rendszerint rosszabbak az ugyanolyan körülmények között készült faalapú lemezek tulajdonságainál. Ennek a tanulmánynak a célja az, hogy megvizsgálja a Pannónia nyár kérgéből készült hő...
Article
Full-text available
This study investigated how the Populus × euramericana cv. Pannónia bark behaves in an environment containing formaldehyde. Prism shaped samples were formed from the bark and the prisms were kept in formaldehyde contaminated atmosphere for 1, 2, 5, 10, 18 and 36 days. After the contamination, the amount of the formaldehyde adsorbed and later the de...
Article
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In terms of reduced energy consumption and simultaneously promoting woody biomass sustainability, researchers are seeking energy-efficient materials, originating from forestry and agricultural residues, for application in the building sector. In this study, bark-based panels overlaid on both surfaces with three different fibreglass types and two ty...
Article
Full-text available
One of the main properties of solid materials are their stiffness. Acoustic vibration non-destructive tests have been successfully used to predict the stiffness, i.e. Young’s modulus or modulus of elasticity (MOE) values of solid wood and wood-based panels. In this work, there was an attempt to evaluate the relationship of dynamic MOE longitudinal...
Article
Full-text available
Beside the reduction of greenhouse gas emission the adsorption and bounding of carbon dioxide is also an important issue to protect the environment from irreversible harms. By photosynthesis produced wood material mostly built up from the CO 2 content of the atmosphere and it is stored until burning or natural decay of the material. Log homes seque...
Article
Full-text available
Buildings in general, consume and lose huge energy amounts through their heating and cooling systems. Thus, effective thermal insulation materials required to endow on energy shaving attainments. For this research, bark particles were used as raw materials for the manufacturing of low-density thermal insulation panels. The aim of this work was to d...
Article
A study of tylosis in European Turkey oak ( Quercus cerris L.) shows correspondences in the formation of tyloses and of regular cell walls. The outer tylosis wall has a smooth, granular surface with simple perforations analogous to that of the primary wall of ordinary cells. The underlying wall stratum shows parallel oriented macro-fibrils, normall...
Article
Full-text available
This work aimed to investigate the effects of the length of finger-contacted surfaces and oil palm wood densities on bending and compressive properties in the case of finger-jointed oil palm wood products (FJOP). The FJOP were manufactured from oil palm wood raw materials of three different density ranges (303 kg/m 3 ± 14 kg/m 3 , 381 kg/m 3 ± 24 k...
Article
Full-text available
Thermally treated and ground poplar bark was used as the raw material for pressed bark insulation panels. Bark chips were treated for one, two, and three hours at 180 °C after a slow warming, drying process. The physical and mechanical properties of the pressed panels were investigated and compared to each other and to the control panel made of unt...
Article
This paper aimed to investigate the temperature dependence of thermal conductivity of heat-treated rubberwood (HTR). Rubberwood specimens were thermally treated at 180°C with three different durations of 15, 25 and 35 h, respectively. Thermal conductivity values of HTR at various mean temperature ranges were then examined. That of untreated rubberw...
Article
Full-text available
Nutrient removal has become one of the key challenges for wastewater treatment facilities all over the world due to the harmful effect of these pollutants on water bodies and ecosystems known by eutrophication, however, most of the currently used technologies are not focused on nutrients recovery from wastewater. Recently, using agricultural waste/...
Article
The apparent thermal conductivity of several insulation materials was measured over a range of temperatures. A newly developed multilayer reflective insulation system called Mirrorpanel was tested against existing products. Mirrorpanel samples were prepared using layers of aluminum foil (emissivity of 0.11) and coated paper (emissivity of 0.52) sep...
Article
Full-text available
Given the great importance of timber measurement, various methods for industrial timber dimensional control have been established in the practice over the last decades. They allow generating the relevant results for calculation of the prices at different locations, independently of the measurement time. These methods range from simple manual measur...
Article
Full-text available
An energetic model of a typical log home was placed in ten different regions of Russia and examined the yearly heating energy demand. The building was supplied with three different types of windows to demonstrate the effect of windows on the heating energy demand. In a 108 m² building, changing the 3.5 W/m²K thermal insulation capacity windows to 1...
Article
Full-text available
Changes in the thermal conductivity and density of Pannónia poplar (Populus x euramericana cv. Pannónia) and spruce (Picea abies) caused by heat treatment were examined. The specimens were treated at 180 °C for 15, 25 and 35 h. Treatment duration had different impact on both the density and the thermal conductivity of poplar and spruce. The density...
Article
Full-text available
The problem of industrial use of tree bark is relevant and has practical importance for complex processing of wood raw material. Barks are available in Hungary and Russia in large quantities, but they are not widely used for different purposes than producing energy. One of the perspective areas of utilization of tree bark is its use as raw material...
Article
The utilization of large amounts of bark coming from the timber harvesting poorly implemented, most common solution for it is the energy production, namely burning. In this research had been developed new uses, resulting in higher value-added utilization. As natural bark protects the live parts of trees in the case of small forest fires, it is also...
Article
Wood frame houses are usually made of softwood species in Europe and North America. But many countries have a great population of different hardwood species, e.g. poplar. This study investigates the possibility of using poplar, instead of pine for wall frame construction of lightweight houses focusing on the mechanical properties of the panels. Ver...
Article
Full-text available
p class="p1">A fűrészipar – mint a legtöbb üzleti vállalkozás – nyereségorientált piaci szektor, amelynek a célja a rendelkezésre álló nyersanyag hatékony feldolgozása a lehető legjobb minőségű és értékű termékké, illetve annak értékesítése partnerek számára. Céljai eléréséhez erőforrásait úgy kell optimalizálni, hogy a rendelkezésre álló eszközeit...
Article
Full-text available
Two oak cant timbers were sawn up to a total of 58 boards. As a dependent variable, the energy consumption while manufacturing a board was measured. As influencing variables, timber and saw blade characteristics were assessed, including density, moisture content, log feed speed, blade profile, and sawing sequence. Four types of forces acting in a s...
Article
Full-text available
The utilization of natural raw materials has been practiced for centuries. Of raw materials, wood and its bark have outstanding significance because of their special chemical components and unusual structure. Annual bark production is estimated to be between 300 and 400 million m³. The bark of different tree species has been used extensively in or...
Article
The utilization of natural raw materials has been practiced for centuries. Of raw materials, wood and its bark have outstanding significance because of their special chemical components and unusual structure. Annual bark production is estimated to be between 300 and 400 million m3. The bark of different tree species has been used extensively in or...
Article
Full-text available
p class="p1">A cikk egy olyan kutatásról számol be, mely a fenyő faanyag behozatal szállításból adódó környezeti terheit az alábbi két területen mérte fel: üvegházhatású gázok kibocsátása nem megújuló primer energiaigény. Mindezt azzal a céllal tette, hogy megállapítsa: ezek a számszerűsített környezetterhek hogyan módosítják az import fenyő faa...
Article
Heat exchanger design for low energy buildings with thermal block energy storage is a critical component of the overall system performance. Geometric modifications proposed to improve the effectiveness of a heat exchanger in such a building have been examined through simulations and experiments. Of the considered modifications, one configuration (i...
Article
This article introduces an insulation system that takes advantage of the low thermal conductivity of still air and is made of wood and paper. The insulation, called the Mirrorpanel, is constructed as a panel of closely spaced layers of coated paper and held together in a frame of wood or fiberboard. Panels have been fabricated and tested at the lab...
Article
Full-text available
Tanulmányunkkal szeretnénk bepillantást adni a spline függvény felfedezésének történetétől a jelenleg alkalmazott módszerekig. Első cikkünk foglalkozik a spline függvények feltalálásával és az elmúlt évszázadokban történt fejlődésükkel. A látszólag száraz matematikai képletekben megjelenő függvények nagyon gyakorlatias megoldások, éppen ezért a mai...
Article
Full-text available
Ez a tanulmány a spline függvények feltalálásával, történetével, fajtáival és alkalmazásukkal kapcsolatos sorozat második része. A spline-okat elsődlegesen mérnöki feladatok és problémák megoldására fejlesztették ki. A spline módszerek könnyű kezelhetősége viszont megnyitotta az utat specifikus spline módszerek kifejlesztésére. Az első részben átte...
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Full-text available
p class="p1">Magyarországon évente közel 600 000 m<sup>3</sup> kéreg keletkezik az elsődleges fafeldolgozás során. A legtöbb esetben melléktermék szerepbe szoruló kéregapríték hőszigetelő képessége megfelelő előkészítés mellett alig marad el az általánosan használt szálas és habosított szigetelőanyagokétól. Az ismertetett kutatás során a tölgyfa (...
Article
Full-text available
A method is presented to determine the optimum log feed speed of a bandsaw based on its power consumption. Three timber species—oak, beech and pine—were sawn under real sawing conditions in a mill. The target of the experiment was to find the optimum log feed speed with the following characteristics: Minimum energy consumption per unit volume sawdu...
Article
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In present work, the possibility was explored to use a solid block for space heating. The block was placed in a test house with low energy characteristics. Computations revealed that heating period greatly depended on the rate of heat withdrawal. With a rate of 122 W, the required indoor temperature (20º C) could be maintained for a heating period...
Article
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p>Vietnam jelentős erdőterülettel – benne primer erdőkkel is – rendelkező ország. A huszadik században az ország erdei nagy változásokon mentek át, mind összetételüket mind mennyiségi részarányukat tekintve. A 1940-es évektől a területi mélypontot jelentő 90-es évekig jelentős erdőterületeket veszített és a megmaradt erdők is károkat szenvedtek. 19...
Article
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An experimental study of wood impregnation was implemented by applying centrifugal methods. The impregnants were a 10% aqueous solution of potassium chloride and a 2% aqueous solution of borax. Birch (Betula pendula) and aspen (Populus tremula) wood samples in different moisture content were tested. The impregnation time in the centrifugal device w...