The effect of open air conditions on the properties of wooden material

In this study, the impregnation materials of Tanalith-C (CCA) and Protim 230 WR were used as preservative and water repellant. Wooden materials were taken from beech and black pine. The sampleswere made subject to weathering conditions for one year. At the end of this period, changes occurred in the samples’ bending strength, compression strength and physical properties were examined. As a result of this study, it was observed that no significant variations occurred in mechanical values of the impregnated samples; however, severe losses occurred in case of the non-impregnated samples. It was seen that impregnation type provides different protection according to the type of the wooden material.It was observed that discoloration is more significant in the  on-impregnated samples compared with those impregnated. Both of the impregnation materials provide sufficient protection

Effect of surface roughness on drying speed of drying lamellas in veneer roller dryer

Lamellas, which are defined as top layers of multilayer parquet and favourable to wood veneer can be dried in jet ventilated automatic veneer roller dryer due to short drying period. The objective of this study is to determine the effect of surface roughness on the drying speed of the veneer roller dryer. Quercus spp., frequently used tree specie in Turkish solid wood and multilayer parquet industries was chosen as material in this study. Pre-dried lamella blocks were cut into 4 different machines. As aresult, 4 test groups of lamellas displaying different surface roughness values were obtained. Lamellas which belong to each of these 4 test groups were also divided into 2 sub-groups and dried at 90 and 130°C drying temperatures. Drying was evaluated in relation to drying speed. Mitutoyo SJ 301 profilmeter was used for determining surface roughness values. Drying speed of lamellas was expressed as: dividing difference of initial moisture content and final moisture content values to dryingtime value. The result of variance analyses showed differences between groups as surface roughness values. There was no difference between groups as drying speed were determined at 90 and 130°C temperatures. Furthermore, the relation between surface roughness values and drying speed was searched using correlation analysis and no significant relationship was found. Finally, it was determined that there was no effect of surface roughness on drying speed in radial cut, pre-dried lamellas, which have surface roughness values between 10.464 and 15.064 ìm, drying in jet ventilated roller dryer, at 90 and 130°C temperatures

The effects of heat treatment on physical and technological properties and surface roughness of European Hophornbeam (Ostrya carpinifolia Scop.) wood

Heat treatment of wood is an effective method to improve the dimensional stability and durability against biodegradation. In this study, the effects of heat treatment on physical properties and surface roughness of European Hophornbeam (Ostrya carpinifolia Scop.) wood were examined. Samplesobtained from Alapli-Zonguldak Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures and for varying durations. The physical properties of heat-treated and control samples were tested, and oven-dry density, air-dry density, and swelling properties were determined. The mechanical properties of heat-treated and control samples were tested, and compression strength parallel to grain, bending strength, modulus of elasticity in bending, Janka-hardness (cross-section,parallel and perpendicular to grain), impact bending strength, and tensile strength perpendicular to grain were determined. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements by the stylus method were made in the direction perpendicular to the fiber. Four main roughness parameters, mean arithmetic deviation of profile (Ra), mean peak-tovalleyheight (Rz), root mean square roughness (Rq), and maximum roughness (Ry) obtained from the surface of wood were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Significant difference was determined (p = 0.05) between physical and technologicalproperties, and surface roughness parameters (Ra, Rz, Ry, Rq) for three temperatures and three durations of heat treatment. Based on the findings in this study, the results showed that oven-dry density, air-dry density, swelling, compression strength parallel to grain, bending strength, modulus of elasticity in bending, Janka-hardness (cross-section, parallel and perpendicular to grain), impact bending strength, tensile strength perpendicular to grain and surface roughness values decreased withincreasing treatment temperature and treatment times. Increase in temperature and duration further diminished technological strength values of the wood specimens. European Hophornbeam wood could be utilized by using proper heat treatment techniques without any losses in strength values in areas where working, stability, and surface smoothness, such as in window frames, are important factors

Effects of heating treatment on some of the physical properties of varnish layers applied on various wood species

The aim of the current study is to determine the effects of different heat treatment and varnish combination applications on some of the physical properties of wood materials sampled from limba (Terminalia superba), iroko (Chlorophora excelsa), ash (Fraxinus excelsior L.) and Anatolian chestnut (Castenea sativa Mill.) species. The heat treatment was applied at two levels (150 and 180°C) for both 3 and 6 h period. Once heat  treatment was conducted, four types of varnish layers (cellulose lacquer, synthetic varnish, polyurethane varnish and water based varnish) were applied to the materials. After the treatments application, color, brightness and surface roughness of varnish film layers of the treated woods were measured. The effects of heat treatment and varnish combination  applications on the earlier mentioned variables were analyzed according to the study design (factorial design with 4 (species) x 2 (heat) x 2 (duration) x 4 (varnish) = 64 experimental units). For significant analysis of variance (ANOVA) , Duncan mean separation test was performed to separate the interaction combinations. Results of the study indicated that surface roughness increased on wood samples for all four wood species treated with cellulose lacquer and synthetic varnish and across all heating  treatments. However, surface roughness decreased for all wood species depending on heating temperature and time. As such, the value of brightness also decreased for all four wood species across all the  treatment combinations. The results obtained from the upper surface of the enforcement process are thought to contribute to the national economy.Key words: Heating treatment, cellulose lacquer varnish, synthetic varnish, polyurethane varnish, water based varnish, surface roughness, brightness, color changes

Effects of drying methods of lamellas used in multilayer parquet manufacturing on surface roughness and bonding strength

The objective of this study is to determine surface roughness and bonding (tensile shear) strength of lamellas (top layer of multilayer parquet) which were cut away from green lumber and dried by different types of drying methods. Also, finding out the most convenient manufacturing method as surface roughness, bonding strength properties was aimed by comparing results with surface roughness and bonding strength of lamellas, which were cut away from dry lumber as seen in practice. Flat sawn green lamellas with 5 and 2 mm thicknesses, which were cut away from Iroko lumber by means of thin cutting frame saw, were dried with 3 different drying methods such as drying in lumber drying kiln, jet ventilated automatic veneer roller dryer and veneer press dryer. Effect of drying temperature on surface roughness and bonding strength was also determined by applying 3 different drying temperatures as 60, 100 and 140°C in jet ventilated automatic veneer roller dryer. In addition, lamellas with the same thicknesses were manufactured from dry lumber by means of the same thin cutting frame saw mentioned above. As the result of analysis of variance showed, differences between test groups were determined as surface roughness. Consequently, effect of drying method on surface roughness was found. Also, surface roughness values were determined to be increasing as drying temperature increases when drying in veneer roller dryer. Surface roughness values of lamellas dried in lumber drying kiln were found to be higher than those cut away from the dry lumber as expected. Differences exist between test groups as bonding strength was determined by means of analysis of variance. The biggest bonding strength was found in lamella group which were cut away from dry lumber and mentioned as comparison group. It was found that no relation existed between bonding strength and temperature increase drying in veneer roller dryer. Also, it was determined that no significant relation was found between surface roughness and bonding strength as the result of correlation analysis. Conclusively, it was found that lamella manufacturing method, cutting away from dry lumber, was the most convenient method for obtaining the best bonding strength in multilayer parquet production.Key words: Drying method, multilayer parquet, surface roughness, bonding strength

Analysis of forest product trade relationships between Turkey and European Union member states

The countries have needed to strengthen their trade relationships in the face of increasing competition conditions with globalization and a lot of unions emerged all over the world. The European Union, remaining in the foreground as an economical, commercial and political factor in these unions, possesses considerable influence, which a lot of countries want to be involved in. Turkey, being in the European integration process, looks for a place in European Union (EU) with its own resources and production power. Production and foreign trade data of the forest products industry, being among Turkey’s important sectors, were compared with 25 different EU countries by using hierarchical cluster analysis, and Turkey’s trade relationship was determined. The production amounts, import and exportamounts and the values, between 2002 and 2006, belonging to the EU member countries and Turkey were used. It has been found that all countries could be divided into nine different groups according tocountries’ forest products industry structures. Competition advantage is experienced in the board sector but not in the paper and lumber sectors. The forest products industry sectors of Turkey have the capacity to compete with EU countries

Covariant And Local Field Theory On The World Sheet

In earlier work, using the light cone picture, a world sheet field theory that sums planar phi^3 graphs was constructed and developed. Since this theory is both non-local and not explicitly Lorentz invariant, it is desirable to have a covariant and local alternative. In this paper, we construct such a covariant and local world sheet theory, and show that it is equivalent to the original non-covariant version.Comment: 22 pages,3 figures, typos and eqs.(11) and (63) are correcte

Examination of forest products trade between Turkey and European Union countries with gravity model approach

The success of getting in the foreign trade forms one of the basic stones of economic development for countries. The current and potential trading volume among countries and determining the main factors affecting trade are quite important. The trade currents of the European Union (EU) countries and Turkey in the forest products industry field were analyzed by the gravity model in this study. For this reason, the panel data method was used for 2000 - 2006 periods. The results show the existence of a high degree of trade integration between Turkey and EU. The estimated gravity models explained 63% of the variation regarding the volume of bilateral trade flows in the EU and Turkey. Furthermore, it was determined that GDP had a positive effect on the amount of foreign trade while distance had a negativeeffect; and Turkey has lower trading volume with the EU countries than its potential regarding the forest products industry field

Kinematic modelling of a 3-axis NC machine tool in linear and circular interpolation

Machining time is a major performance criterion when it comes to high-speed machining. CAM software can help in estimating that time for a given strategy. But in practice, CAM-programmed feed rates are rarely achieved, especially where complex surface finishing is concerned. This means that machining time forecasts are often more than one step removed from reality. The reason behind this is that CAM routines do not take either the dynamic performances of the machines or their specific machining tolerances into account. The present article seeks to improve simulation of high-speed NC machine dynamic behaviour and machining time prediction, offering two models. The first contributes through enhanced simulation of three-axis paths in linear and circular interpolation, taking high-speed machine accelerations and jerks into account. The second model allows transition passages between blocks to be integrated in the simulation by adding in a polynomial transition path that caters for the true machining environment tolerances. Models are based on respect for path monitoring. Experimental validation shows the contribution of polynomial modelling of the transition passage due to the absence of a leap in acceleration. Simulation error on the machining time prediction remains below 1%

Development of Metabolic Indicators of Burn Injury: Very Low Density Lipoprotein (VLDL) and Acetoacetate Are Highly Correlated to Severity of Burn Injury in Rats

Hypermetabolism is a significant sequela to severe trauma such as burns, as well as critical illnesses such as cancer. It persists in parallel to, or beyond, the original pathology for many months as an often-fatal comorbidity. Currently, diagnosis is based solely on clinical observations of increased energy expenditure, severe muscle wasting and progressive organ dysfunction. In order to identify the minimum number of necessary variables, and to develop a rat model of burn injury-induced hypermetabolism, we utilized data mining approaches to identify the metabolic variables that strongly correlate to the severity of injury. A clustering-based algorithm was introduced into a regression model of the extent of burn injury. As a result, a neural network model which employs VLDL and acetoacetate levels was demonstrated to predict the extent of burn injury with 88% accuracy in the rat model. The physiological importance of the identified variables in the context of hypermetabolism, and necessary steps in extension of this preliminary model to a clinically utilizable index of severity of burn injury are outlined