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Anatomical properties of pedunculate oak (Quercus robur L.) wood have not been previously investigated in Serbia, so bearing in mind economic-productive and ecological significance of this species, it was one of the main reasons why this research was conducted. In this paper, fibre length (FL), double cell-wall thickness (DCWT) and fibre lumen diameter (FLD) were measured in pedunculate oak wood from two different sites. The study was conducted at two sites (Donji Srem – MU „Raškovica-Smogvica” and Gornji Srem – MU „Kupinske grede”), situated along the Sava River and characterised by different ecological conditions, including flooding regimes. Measurements were conducted in radial direction, from pith to bark, in order to assess variation of investigated characteristics with cambial age, between two sites and between individual trees within each site. All measured characteristics from both sites increase going from pith to bark apart from FL in the area of Donji Srem – MU „Kupinske grede” that reaches maximum value in the central part of xylem and then decreases. Hydrological site conditions affect the dimensions of pedunculate oak wood fibres and these values are a bit higher in Gornji Srem – MU „Raškovica-Smogvica”, due to a greater quantity of available water., Anatomska svojstva drva hrasta lužnjaka (Quercus robur L.) do sada nisu istraživana na području Srbije, a imajući na umu golemo značenje te vrste u ekonomsko-proizvodnome i ekološkom smislu, to je bio jedan od glavnih razloga za provedbu ovog istraživanja. U radu je izmjerena duljina vlakanaca (DV), dvostruka debljina stijenki (DDS) i promjer lumena vlakanaca (PLV) drva hrasta lužnjaka s dva različita staništa. Istraživanje je provedeno na staništima Gornji Srem – GJ „Raškovica-Smogvica” i Donji Srem – GJ „Kupinske grede”, koja se prostiru duž rijeke Save, a karakteriziraju ih različiti ekološki uvjeti, uključujući i režim plavljenja. Mjerenja su provedena u radijalnom smjeru, od srčike prema kori, kako bi se utvrdile varijacije istraživanih svojstava ovisno o starosti kambija, o različitosti dvaju lokaliteta te o razlikama među stablima unutar istog lokaliteta. Utvrđeno je da se sve izmjerene vrijednosti drva s oba lokaliteta povećavaju u smjeru od srčike prema kori, osim DV-a na području Donjeg Srema – GJ „Kupinske grede”, koji maksimalnu vrijednost dosežu u središnjem dijelu ksilema i potom se smanjuju. Hidrološki uvjeti staništa uvelike utječu na dimenzije drvnih vlakanaca hrasta lužnjaka i te su vrijednosti zbog veće količine raspoložive vode nešto veće u Gornjem Sremu, u GJ „Raškovica-Smogvica”.

This study investigated the variations in tracheid length of Pseudotsuga menziesii (Mirb.) Franco from three sites in Croatia in relation to cambium age, within- and between-site differences, and growth rate. Tracheids are the main structural element in P. menziesii wood, varying in length following different patterns that should be precisely determined. After the maceration procedure, earlywood tracheid length (EWTL), latewood tracheid length (LWTL), annual growth ring tracheid length (RTL), earlywood ring width (EWW), latewood ring width (LWW), and annual ring width (ARW) were measured in selected annual growth rings. The significant effect of annual growth rings and zone interaction for EWTL and LWTL, as well as of annual growth rings, trees, and sites for RTL, was determined. The results conclude on the differences between the trends in EWTL and LWTL from pith toward the bark. In addition, the correlation analysis between the tracheid length and different growth patterns was investigated, and very weak or no association between the variables was detected. This research contributes to better understanding the degree of wood uniformity of P. menziesii from the technological perspective, as well as the variability factor in the optimization of forest management with favoring overall wood quality.

White poplar (Populus alba L.) is becoming interesting species for breeding because of its tolerance to drought and variations in levels of ground water. However, its wood anatomical properties have not been sufficiently investigated, whereas data on cell wall area can certainly be interpreted in relation to wood density. Fiber lumen area, vessel lumen area and ray area of white poplar juvenile wood from two sites in Croatia was measured. Cell wall area (%) was calculated as a percentage remain after detracting fiber lumen area, vessel lumen area and ray. Variations in cell wall area in radial direction (from pith to bark) and between trees within two white poplar populations were investigated. Preliminary results indicate that cell wall area varied significantly from pith to bark and between trees within one site. In juvenile wood from the other site, both variations were non-significant. In conclusion, variation significance demonstrates different cell wall area radial trends from both sites, suggesting that only one site confirms variable properties within juvenile wood. As well, different tree effect on cell wall area within two populations was detected.

There is a growing trend in the world of planting fast growing species (rotations 5 to 10 years). Their primary purpose is the production of wood fibers and biomass, but they certainly represent the potential in making solid wood products as well. One of the fast- growing species is Paulownia sp., a species of extremely fast growing wood. Plantation breeding of Paulownia sp. in Croatia is increasing, although there is a little knowledge about the technical properties of Paulownia wood and its end use is questionable. This paper presents preliminary results of some physical properties of two Paulownia hybrids juvenile wood planted in the area near town Glina in the Republic of Croatia. One hybrid is 9501 ((Paulownia fortunei × Paulownia elongata) × (Paulownia fortunei × Paulownia tomentosa)) and the other hybrid is Shan Tong (Paulownia fortunei × Paulownia tomentosa). The aim of this study was to investigate physical properties of two Paulownia hybrids juvenile wood from one site in Croatia ; to determine differences in physical properties of wood between two hybrids and to evaluate correlation between density and shrinkages of each hybrid. Significant differences in oven dry density, basic density and density at maximum MC, between two hybrids were determined. There is no statistically significant difference in longitudinal, radial, tangential and volumetric shrinkages between two hybrids.

Investigation of physical and mechanical properties of wood are important for application of wood as a raw material. Nowadays, large quantities of wood from fast- growing species, especially from agricultural unusable land, are available on the market. One of them are poplars. The available data on physical and mechanical properties of white poplar wood grown in Croatia are insufficient. In this paper, some of this properties were investigated on white poplar wood (Populus alba L.) from the region near Varaždin. As well, the distribution of this properties from pith to bark was investigated. This preliminary study was carried out on five trees, using only segments with north and south orientation in the wood at breast height. This paper presents charts of listed properties from pith to bark for trees where the correlation of properties was greatest. The average values of results in this preliminary study are: density in absolute dry condition is 0, 413 g/cm3, density at 12% of moisture content is 0, 429 g/cm3, static bending strength is 62, 5 MPa, modulus of elasticity at static bending is 5, 2 GPa, compression strength parallel to grain is 34, 3 MPa. Correlation between properties in some trees was satisfactory, but in order to determine statistical reliability, research must be continued on larger number of samples.

Relationship between strength and density of wood plays important role in application of wood in construction. Available information on technical properties of sycamore maple wood are modest, and science based information on many important technical properties of this wood are missing. Some physical and mechanical properties of sycamore maple wood from Medvednica region were investigated. Relationship between strength and density as an indicator of wood quality was calculated. Wood quality was determined by strength quotient, bending quotient and toughness quotient. Variations of mentioned quotients from pith to bark were investigated. Statistical analysis showed no significant differences in distribution of quotient values from pith to bark. Quality coefficients were compared to available data on some other wood species.

Different concentration of chemicals in solution, temperature and curing period were used for common beech wood modification with Citric acid (CA). In distilled water (at 60 °C) extracted specimens were impregnated with citric acid (CA) water solutions of different concentrations with phosphate catalyst. After impregnation, specimens were air-dried and then cured at elevated temperatures using different regimes. The effects of different modification regimes were assessed through the values of weight percentage gain (WPG), anti swelling efficiency (ASE), mass loss caused by leaching (MLL) and leachability coefficient of gained mass (LCM). Optimal combination of modification parameters was chosen for each of mentioned properties and then only one optimal combination of modification parameters was selected. Compression strength parallel to the grain and biological durability of beech wood after modification by optimal regime were researched and data presented.

Spruce veneers (Picea spp.) and oak veneers (Quercus spp.) were impregnated by halogen free organophosphorous compound (BHOS) with dimethylol dihydroxyethyleneuree (DMDHEU) as a cross-linking agent and magnesium chloride (MgCl2) as a catalyst. Impregnated veneers were gradually dried to absolute dry condition. Afterwards veneers were thermocondensed at the temperature of 140 °C for 5 hours. For fire resistance investigation two different methods already established for textile materials were applied. Investigations of fire resistance of modified veneers have shown that wood modified by BHOS could be considered as a "self-extinguishing" material.

Tree heath (Erica arborea L.) is an evergreen shrub that grows mainly in Mediterranean region. This species tends to grow in areas such as macchia shrub lands, dry evergreen scrublands, forest roadsides and forest outskirts which have a lot of light and sun though daytime. Tree heath is not a commercial timber species, it occurs as a result of forest roads and forest fireroads construction. This wood species is interesting because of its briarwood. Briarwood is tumour like outgrow that develops between root and trunk and it’s commonly used in making bowls of tobacco smoking pipes and knife handles. The trunk can also be used for variety of products because of its relatively good mechanical properties and nice colour and texture. Material for this study was taken from tree heath (Erica arborea L.) shrubs growing on island of Rab in Croatia. In this study density and dimensional stability of briarwood and trunk of tree heath were investigated. Also some mechanical properties of trunk such as bending strength and compression strength parallel to the grain were studied.

Kvaliteta sirovinskog potencijala, kao i tradicija u preradi drva te izraženi trendovi povećanja uporabe drvnih ostataka kao ekološkog i obnovljivog materijala, imaju veliku ulogu u proširenju domaće industrije i tržišta peleta. Iako ovisni o potražnji na tržištu i gospodarskoj isplativosti u odnosu na neobnovljive izvore energije, obnovljivi se izvori mogu i moraju početi bolje iskorištavati. Primjeri iz Austrije, Irske i Hrvatske ističu neke od ključnih čimbenika koji su utjecali na razvoj i stanje na tržištu peleta u tim zemljama. Na osnovi pregleda početnog i trenutačnog stanja i analize spomenutih tržišta, u radu su definirani kritični čimbenici koji utječu na razvoj domaćeg tržišta peleta. Kritični društveno-gospodarski čimbenici za razvoj nacionalnog tržišta peleta koji proizlaze iz predstavljenih analiza su: financijski poticaji, postojanje snažne drvno-prerađivačke industrije, strogi zahtjevi kvalitete na kotlove na pelete, uspostava djelotvornih mehanizama kontrole kvalitete za pelete, namjenski programi edukacije i certificiranje instalatera, povezivanje subvencija sa zahtjevima kvalitete za kotlove i certificiranjem instalatera, promotivne kampanje, poticanje nabave sustava grijanja na pelete za javne zgrade i razvoj poticaja za tvrtke koje pružaju energetske usluge.

Ovaj diplomski rad se bavi oblikovanjem suvremenog namještaja koji ideje i koncept temelji na tradicionalnim etnografskim elementima Hrvatskog zagorja. Dizajn proces je kao rezultat dao novo rješenje u području namještaja za sjedenje koje ima sve preduvjete da se definira kao izvoran hrvatski proizvod trajnih vrijednosti. Iako stvoriti izvozno konkurentan finalni proizvod nije jednostavno, poštujući i uvažavajući postavljene zahtjeve i ciljeve došlo se do koncepta ekološkog i zdravog proizvoda od čiste drvne sirovine porijeklom iz RH, oblikovno jednostavnog, naglašene multifunkcionalnosti te prepoznatljive kvalitete i kulture. Analizom, prikupljanjem podataka, činjenica i informacija te njihovom sintezom oblikovan je naslonjač namijenjen opremanju suvremenih interijera, naročito onih u kojima se osjeća svojevrsna povezanost s okolinom kroz izbor prirodnih materijala ili ostala odabrana oblikovna rješenja. Na taj je način zadani konceptualni problem riješen optimalnim oblikovno-konstrukcijskim rješenjem proizvoda, uz unapreñivanje odnosa suvremeni korisnik-namještaj-prostor. Što se tiče uspješnosti i postojanosti izvedbenog rješenja, odnosno same kontrukcije, izradom modela ili prototipa omogućuje se i olakšava predočavanje budućeg proizvoda, objašnjavaju ključna mjesta i potrencijalni nedostaci te provjeravaju zahtjevi dimenzija, funkcioniranja i konačne izvodljivosti.