The objective of the experimental research presented in this paper was to analyze the roughness parameters characterizing the final quality of the birch wood surfaces, industrially sanded with three successive grit sizes, namely 100, 120 and 150. Sets of samples were analyzed for each sanding direction, parallel and perpendicular to the wood grains, respectivelly. The variables of the processing parameters were considered to be the feed speed and the cutting depth. łhe roughness was measured on a standard optical profilometer type FRT MicroProf for the two cases of wetting and no wetting the measured area. Three roughness parameters were determined: Ra, Rk and Rpk. The assessment of the quality of the sanded surfaces was carried out by comparing these parameters, depending on the applied processing parameters. The experimental results were analyzed with ANOVA test of variance with two factors for each sanding technology and direction of processing, at the same feed speed and various cutting depths, for both dry and wet sanding. It was found that the quality of the prewetting surfaces was very close to that of the dry sanded surfaces, fact that recommends the use of dry sanding, thus eliminating additional labor costs. The final sanding parallel to the wood grains recorded best results for the dry process with 150 grit size. ANOVA conclusions have shown that the parallel sanding operation with low speeds is significantly influenced by the cutting depth and also, that the influence disappears at high feed speeds. When sanding perpendicular to the wood grains, on the other hand, the cutting depth has a significant influence when feed speeds are higher. The results of the present research go into recommendations of some sanding technologies for birch wood surfaces, in the idea of introducing birch wood as timber raw material for furniture production also in Romania, too.

The article presents the data obtained for the thermal conductivity coefficient (λ) at external temperatures between -20°C and +15°C and a temperature difference T=10,15,20,25,30°C. The specimens included in this study, designed for cladding the inner walls, are differentiated by the type of ceramic matrix (three different receipes were used) and by the hemp hurds percent embedded into the ceramic mass (5%, 10% and 20%). This analysis aims to evidentiate the influence of the ceramic matrix components on the thermal conductivity value for specimens with the same hemp hurds percentage and also to highlight the specimens with the highest thermal efficiency.

The measurement uncertainty is a quantitative indicator of the results quality, meaning how well the result represents the value of the quantity being measured. It is a relatively new concept and several guides and regulations were elaborated in order to facilitate laboratories to evaluate it. The uncertainty components are quantified based on data from repeated measurements, previous measurements, knowledge of the equipment and experience of the measurement. Uncertainity estimation involves a rigorous evaluation of possible sources of uncertainty and good knowledge of the measurement procedure. The case study presented in this paper revealed the basic steps in uncertainty calculation for formaldehyde emission from wood-based panels determined by the 1m3 Chamber method. Based on a very well defined Ishikawa Diagram, the expanded uncertainty of 0.044mg/m3 for k=2, at 95% confidence level was established.

The paper presents a study concerning the modifications induced by different freezing conditions upon the moisture diffusion in spruce (Picea abies L.) wood. The diffusion coefficients in radial and tangential directions were determined at 20°C/35% and 40°C/35%, on wood samples initially subjected to rapid freezing (at -10°C/h freezing rate), respectively slow freezing (at -1°C/h freezing rate), then maintained for 1 week in frozen condition, comparatively to samples originating from the same log but stored in an open yard for three winter months (December-February) and also compared to non-frozen samples. All samples were subjected to the diffusion test after being dried - to 12% mc. These testing conditions were chosen so as to evaluate the influence of the freezing speed (rapid vs. slow freezing) and of the exposure duration to freezing conditions (1 week vs. 3 months) upon the moisture diffusion in spruce wood – which is an important property related to the dynamics of wood drying. The results show that rapid freezing at -25°C do not affect moisture diffusion, while slow freezing (at a freezing rate of -1°C/h) and long-term exposure to negative temperatures increase moisture diffusion by 15-33% compared to unfrozen wood. The higher values were recorded in tangential direction and with the higher test temperature (40°C).

This paper presents specific aspects of traditional wooden gates built in the rural area of the county of Harghita in Romania. One can see the love and appreciation given to woodworking and outdoor elements of household adornment, beautiful inside transmitted outside. Constructive elements and ornaments are given specific geographical area. These gates belong to our national cultural heritage.

The paper presents the results of the research conducted to obtain new ecological composites that could be used for thermal insulation of buildings. The obtained panels are made of ecological materials that do not affect the human health (wood chips and fibers, host of hemp, textile fibers, wool and reed). The testing was performed in eight points, for an internal temperature of T=200C and an outdoor temperature situated in the range of -200C÷200C). As the tests conducted, the results showed that the best insulating capacity belonged to a composite which has wood fiber and wool in its structure, followed a composite which has wood chips, hemp particles and wool in its structure.