Export Competitiveness and Sustainable Development of the Ukrainian Timber Industry

This paper conducts a comprehensive analysis of the export dynamics within the Ukrainian timber industry, emphasizing its pivotal role in the national economy. The study begins by outlining the research objectives, context, and innovative methodologies, setting the stage for a deep dive into the theoretical underpinnings of sustainable and competitive trade. It explores Ukraine’s rich forest biodiversity across varied vegetation zones and its geopolitical significance. Detailed evaluations of forest resource management, policy frameworks, and institutional support form the core of the analysis. Challenges such as imbalanced export structures and legal inconsistencies are critically examined. The research employs trade gravity models and competitive indicators like the Revealed Comparative Advantage (RCA) and Market Share (MS) to assess factors influencing exports and to forecast potential growth areas. The findings inform strategic recommendations aimed at enhancing export capacity through market diversification, brand development, and legal stability. The conclusion highlights the need for strategic interventions to harness Ukraine’s timber resources sustainably, balancing economic gains with environmental stewardship.

Application of single neuron adaptive PID controller during the process of timber drying

The paper presents a method of using single neuron adaptive PID control for adjusting system or servo system to implement timber drying process control, which combines the thought of parameter adaptive PID control and the character of neural network on exactly describing nonlinear and uncertainty dynamic process organically. The method implements functions of adaptive and self-learning by adjusting weighting parameters. Adaptive neural network can make some output trail given hoping value to decouple in static state. The simulation result indicates the validity, veracity and robustness of the method used in the timber drying process

Mechanical properties of monodirectional Gutou mortise-tenon joints of the traditional timber buildings in the Yangtze River region

The mechanical properties of the monodirectional Gutou mortise-tenon joints of the ancient Chinese traditional timber buildings in the Yangtze River region were studied using the experimental method. Three monodirectional Gutou mortise-tenon joints were designed according to the actual configurations. The failure modes,the hysteretic curves,the skeleton curves, the rotation rigidities, and the energy dissipation capacity of this type of mortise-tenon joints under the low cyclic reversed loading were obtained. The results show that the hysteretic curves of the monodirectional Gutou mortise-tenon joints appear to be Z shape and have obvious pinch effects. During the process of the test,these mortisetenon joints pass orderly through the elastic stage,the yield stage and the failure stage. The energy dissipation capacity of these mortise-tenon joints generally decreases with the increase in the rotation angle. The equivalent viscous damping coefficients of the monodirectional Gutou mortise-tenon joints are between 0. 161 and 0. 193. The results can provide the theoretical base for the computing analysis and repair design of Chinese traditional timber buildings in the Yangtze River region.

Structural Carpentry in Qing Dynasty-A Framework for the Hierarchically Modularized Chinese Timber Structural Design

This article, by using mathematical expressions, offers a scientific framework for understanding how the grading system of Qing′s structural carpentry determines the design and construction in the grand style timber architecture.The Qing′s grand style timber structure, which is ready for prefabrication and assembly, is extremely hierarchical oriented and significantly standardized. The general procedure in designing a grand style timber structure is to start with the grade that defines the basic module (dou kou); next comes with the number of bracket set (cuan), the number of longitudinal bays and the number of purlins which affect its plan and cross section; thirdly choose a roof type that determines its longitudinal section and the facade as well. A series of formulae are conducted to help depict the layout, cross sectional roof curvature and special longitudinal treatments in 4 sloped and 9 spined roofs respectively.

Preservation Strategies of Timber-framed Arch Bridges as Cultural Landscape Heritage

Theoretical study on and safeguarding of cultural landscape heritage has been put on the agenda of heritage protection in Zhejiang and Fujian provinces.The safeguarding of timber-framed arch bridge heritage in the past 5 decades could be classified into 3 stages,and heritage protection in all 3 stages was closely related to original meaning of "landscape",which proved that timber-framed arch bridge heritage had profound inside information,and the safeguarding of timber-framed arch bridge from the perspective of cultural landscape heritage was worth further study.Safeguarding of timber-framed arch bridge cultural landscape heritage focused on integrated conservation,but not protection of individual bridges.Integrated conservation of world heritage is to maintain and restore the integrated environment landscape of the heritage,thus protection of timber-framed arch bridge heritage is not only to explore its architectural craftsmanship,but also to lay a foundation for the dynamic succession of such craftsmanship as intangible cultural heritage.Value of the existing timber-framed arch bridges as historic building heritage was discussed,and it was proposed that ultimate objectives of the safeguarding could be realized step by step from 3 layers.

Analysis of moisture diffusivity of larch timber during convective drying condition by using Crank＇s method and Dincer＇s method

Two analytical procedures （Crank＇s method and Dincer＇s method） for porous solid materials were reevaluated and used to determine moisture diffusion coefficients and moisture transfer coefficients for larch lumber subjected to drying. A diffusion-like equation was used to describe drying process data. The lumber was idealized in the modeling as infinite plates. The moisture transport process inside the board was assumed to be one-dimensional. The macroscopic drying kinetics curves of larch timber at particular conditions were determined experimentally. Based on these data, calculation for both the moisture diffusion coefficients and moisture transfer coefficients by the Dincer＇s analytical procedure were made. The dynamic moisture diffusion coefficients by the traditional Crank＇s method were calculated. In general, diffusion coefficients calculated by the Dincer＇s method were all higher than those by Crank＇s method. These results could be due to the differences between two analytical methods and also different characteristics between solid moisture diffusion process and heat transfer process. Therefore the analysis and solution procedures of moisture diffusion differential equations need to be adapted in the future. With drying temperature＇s increasing moisture diffusion coefficient （D） and moisture transfer coefficient （k） increases accordingly. Also the relationships between diffusion coefficients and temperature as well as material moisture contents were analyzed by using Arrhenius equation and bound water transport theory.

Shifting Private Timberland Ownership in South Carolina: Implications for Management Intensity

Beginning in the late 1970’s forest industry timberland gained the eye of financial investors. Diamond International and Crown Zellerbach were early firms that were purchased for the “break-up value” of their timberland. Timberland was perceived as undervalued by investors and made forest industry firms attractive takeover targets. This started a process where forest industry divested of its timberland. Some firms formed separate entities for its timberland base. Acquisitions and mergers became popular in the industry. Some forest industry companies converted to real estate investment trusts, for tax and defensive reasons. Large institutional investors became interested in timberland as means to diversify their portfolios and increase financial performance. Timber management investment organizations developed to manage and procure timberland for these institutional investors. Today little of the forest industry timberland remains with vertically-integrated forest products companies. South Carolina’s forest industry timberland decreased by about 800,000 ha since 1993 (or nearly 90%). This has implications for the state’s timber supply. Forest industry timberlands were some of the most productive and intensively managed forests in the state. We address how forest management might change on this timberland and how long-term timber supply might be impacted in the state.

Cost-effectiveness analysis of subsidy schemes for industrial timber development and carbon sequestration in Japanese forest plantations

This study uses simulations to investigate the effects of implementing two different Japanese forestry subsidy systems on timber production and carbon stock, and examines the consequences for harvesting strategies. An existing Local Yield Table Construction System （LYCS）, a wood conversion algorithm, and a harvesting cost model were used in the simulations to test the applicability of different subsidies to the thinning of stands. Using forest inventory data collected by local government staff, simulation output was used to calculate forestry profits, carbon stocks, subsidies, the amount of labor required, and the cost effectiveness of investing in subsidies. By comparing the output of simulations based on two scenarios, we found that both the clear-cutting area and the amount of harvested timber were larger under Scenario 2, in which the rules governing subsidy allocations are more relaxed, than under Scenario 1, in which the rules are more restrictive. Because the harvested timber under Scenario 1 was mainly produced by clear-cutting, the forestry profits and the subsidy predicted in the early period of the simulation, were larger under Scenario 1 than under Scenario 2. In contrast, the carbon stock was larger under Scenario 2 than under Scenario 1. The simulation model is likely to be useful for improving Plan-Do-Check-Act cyclesimplemented in Japanese forest management systems.

Comparison of three processing methods for laminated bamboo timber production

Three processing techniques, split-squaring(SS),V-grooving(VG), and split-edging(SE), were evaluated and compared in terms of their processing time and recovery. Semantan bamboo(Gigantochloa scortechinii Gamble) was used as a raw material and the results showed that the VG-method required the longest processing time(32.1 min), followed by the SS-method(18.2 min), and the SE-method(17.9 min). However, the VG-method showed the highest recovery(82.0%) compared to the SS-method and SE-method, 31.0 and 49.4%, respectively. When both processing time and recovery factors were combined with the same weighing factor, the highest value was recorded with the VG-method(49.1), while the SE-method had values of 31.1 and the SS-method 12.8. The results suggest that the VG-method is the best option. However, the V-grooving machine is still a prototype and therefore the SE-method could be an alternative option until the improved V-grooving machine is available.

Selection of superior families of Pinus massoniana in southern China for large-diameter construction timber

This study addresses the increasing demand for large-diameter production timber,and considers the time and space variability of half-sib families of Pinus massoniana.Height,diameter at breast height(DBH)and timber volume of 440 open-pollinated half-sib progeny families were investigated in 14 progeny trials in different years and production regions.An evaluation of the genetic variation of all half-sib families was carried out during the sustainable rapid growth period and individual volumes were characterized as a major index.ANOVA analysis showed that there was considerable variance in the growth traits of most families in different years and on different sites.The variations caused by temporal and spatial changes of the mating system required three selection methods for analysis.The results show that there were differences among the heritabilities of different growth traits by different halfsib progenies.Average heritability values of height,DBH and volume were 0.33,0.34 and 0.36,respectively.Fortyfive superior families were selected in every progeny test,12 were selected in progeny trials by different years and five in different habitat progeny trials.Three superior families(Gui GC553A,Gui GC414A and Gui GC431A)were selected,although in different years and production regions.The genetic gains of timber volume of these selected r families ranged from 1.20 to 47.00%,which could provide a foundation for superior wood property selection and serve as material for seed improvement and extension in surrounding areas.

Evaluation of Mechanical Properties of Cross-Laminated Timber with Different Lay-ups Using Japanese Larch

Japanese larch is one of the main plantation tree species in China.A lack of engineered wood products made by Japanese larch,however,limits its application in wood stnuctures.In this study,based on optimum process parameters,such as pressure(12 MPa),adhesive spread rate(200 g/m^(2))and adhesive(one-component polyurethane),the mechanical properties of Japanese larch-made cross-laminated timber(CLT)with different lay-ups were evaluated by means of the static method.Results of this study showed that variations in lay-ups significantly affected the mechanical properties of CLT.The strength and modulus of bending and parallel compression for CLT increased with the thickness of lumber,while that of bending,parallel compression and rolling shear all decreased with the number of layers.Thickness,layup orientation and the number of layers all had an impact on the strength of CLT.Failure modes obtained from numerical simulation were basically the same as those of experimental tests.There was also strong alignment between theoretical value and test value for effective bending stifness and shear stifness.Thus,the shear analogy method can be used to predict the mechanical properties of CLT effectively.This study proved great potential in using Japanese larch wood for manufacturing CLT due to its good mechanical properties.

Quantitative and financial evaluation of non-timber forest products(case study:Zemkan basin forests,West of Iran)

Although Zagros forests in western Iran lack industrial timber value due to the severe climate and socioeconomics problems, non-timber products are of great value and importance due to their high economic potential and also their potential to improve the welfare of forestdwelling and forest-fringe villagers. This study was done in the forests of the Zemkan basin, an important part of central Zagros forests, Iran, to recognize the non-timber forest products（NTFPS）, investigate their potential economic value and role in people＇s livelihood. Data, collected using forest cruising, participatory observations, interviews with indigenous and local persons and experts, identified wild pistachio resin, wild pistachio fruit, oak fruit and oak syrup（Shokeh manna） among the non-timber products in this basin with total potential harvestable NTFPs of 77.16,771.602, 13248.68, and 1324.868 tons per year,respectively. The economic rent from NTFPs is 33 US$/ha/year and its total expected values with consideration of real interest rate when the exploiter invests the capital in the bank（6.4 %） and when money is borrowed from the bank to execute the incorporated projects（8.4 %） are $516/ha and $393/ha, respectively. Furthermore, families＇ economic share from potential profit of NTFPs is annually$601 per household. In addition wild pistachio resin has the highest share of the total potential profit of NTFPs and its equal to 51 % of the total of potential profit of NTFPs.Therefore, it is suggested that decisions be made to increase the infrastructure and strengthen the local selling market to enhance the cash income from NTFPs. Forest participatory management practices are suggested to organize and improve traditional use of the forests.

An Effective Wood DNA Extraction Protocol for Three Economic Important Timber Species of India

Extraction of DNA from fresh tissues is routine in studies of tropical forest species, but DNA extraction from wood is considered as difficult due to its highly degraded nature and adequate quality of genomic DNA extraction is essential for molecular studies. Very few studies have validated the potential for isolating DNA from dried wood (Heartwood and Sapwood). Wood genomic DNA extraction is difficult from mature timber (Teak (Tectona grandis f;verbanaceae), Black Rosewood (Dalbergia latifolia f;Fabaceae) Ben Teak (Lagerstroemia lanceolata f;Lytheraceae) tissues due to presence of high quantity of secondary metabolites polyphenols, tannins and terpenoids and protein inhibitors. Mostly in laboratories DNA extraction kits are available but by using kits, DNA yield is very low and it is quite expensive too. We have standardized and validated the DNA extraction through manual protocol which is applicable for Bark, Sapwood and Heartwood samples of tree species which contains huge amount of inflexible tissues and fibers. The quality of the DNA was tested by spectrophotometer, gel electrophoresis and PCR (ISSR and SSR) amplification. An avrage DNA yield for heartwood ranges from 0.186 - 0.166 μg/μL and sapwood was ranges from 0.26 - 0.244 μg/μL. Modification of CTAB method was by addition of polyvinylpyrrolidone (PVP) appx 0.25%, variation in Rnase concentration, proteinase treatment with different concentration and incubation time. In order to evaluate the standardized wood genomic DNA extraction protocol, we compared it with the mature leaf and core samples (heartwood and sapwood) of the same timber species. The outcome was also quantified and proved by means of polymerase chain reaction analysis by using ISSR and SSR microsatellite markers conducted with isolated pure DNAs. This modified protocol made increased yield and purity of wood total genomic DNA and facilitate the important application of forensic timber species effort.

A Review on Strengthening of Timber Beams Using Fiber Reinforced Polymers

Fiber reinforced polymer(FRP)has been used in the construction industry because of its advantages such as high strength,light weight,corrosion resistance,low density and high elasticity.This paper presents a review of bonding techniques adopted to strengthen timber beams using FRP to achieve larger spans.Different methods of bonding between FRP and timber beams have been summarized with a focus on the influencing factors and their effects as well as relevant bond-slip models proposed for fundamental understanding.Experimental investigations to evaluate the flexural performance of timber beams strengthened by FRP bars,sheets and wraps have also been critically reviewed to identify key influencing parameters.Limited research available on the shear performance of FRP reinforced timber beams have been analyzed to determine the influencing factors of the shear performance in timber-FRP beams.The paper finally presents an overall summary of the current-state-of-the-art and proposes some future research directions in the field.

Development and Evaluation of Species-Specific Biomass Models for Most Common Timber and Fuelwood Species of Bangladesh

Allometric biomass models are efficient tools to estimate biomass of trees and forest stands in a non-destructive way. Development of species-specific allometric biomass models requires extensive fieldwork and time. Our study aimed to generate species-specific allometric biomass models for the most common fuelwood and timber species of Bangladesh. We also wanted to evaluate the performances of our models relative to the performances of regional and commonly used pan-tropical biomass models. We used semi-destructive method that incorporates tree-level volume, species-specific biomass expansion factor (BEF), and wood density. We considered four base models, 1) Ln (biomass) = a + bLn (D);2) Ln (biomass) = a + bLn (H);3) Ln (Biomass) = a + bLn (D^2H);4) Ln (Biomass) = a + bLn (D) + cLn (H) to develop species-specific best-fitted models for Total Above-Ground Biomass (TAGB) and stem biomass. The best-fitted model for each species was selected by the lowest value of Akaike Information Criterion (AIC), Residual Standard Error (RSE) and Root Mean Square Error (RMSE). The derived best-fitted models were then evaluated with respect to regional and pan-tropical models using a separate set of observed data. This evaluation was conducted by computing ME (Model Efficiency) and MPE (Model Prediction Error). The best-fitted allometric biomass models have shown higher model efficiency (0.85 to 0.99 at scale 1) and the lowest model prediction error (-8.94% to 5.27%) compared to the regional and pan-tropical models. All the examined regional and pan-tropical biomass models showed different magnitude of ME and MPE. Some models showed higher level (>0.90 at scale 1) of ME compared to the best-fitted specific species biomass model.

Axial Mechanical Properties of Timber Columns Subjected to Freeze-Thaw Cycles

The behaviour of timber columns subjected to freeze-thaw cycles under axial compression is presented in this paper.A total of forty specimens,including twenty circular timber columns and twenty square timber columns,were tested under axial compression.The failure modes,ultimate bearing capacity,ductility coefficient,load-displacement curves and load-strain curves were obtained and analyzed.The number of freeze-thaw cycles(from 0 to 80)and the specimens’height(from 225 mm to 360 mm)were considered as the main parameters.After freeze-thaw cycles,there was no obvious change on the surface of the timber columns.The test results showed that freeze-thaw cycles could reduce the ultimate bearing capacity of the timber columns,and the average reduction of the ultimate bearing capacity of the specimen reached 28%.The ductility coefficient of the square specimens subjected to freeze-thaw cycles almost remains constant compared with that of the square timber columns left untreated.While the ductility coefficient of the circular timber columns increases after freeze-thaw cycles.In addition,based on the extensive experimental analysis,a regression formula is derived to predict the ultimate bearing capacity of the timber columns after being subjected to freeze-thaw cycles,which is proved to be reasonable accurate.

Numerical Investigation of Connection Performance of Timber-Concrete Composite Slabs with Inclined Self-Tapping Screws under High Temperature

The timber-concrete composite(TCC)slabs have become a preferred choice of floor systems in modern multi story timber buildings.This TCC slab consisted of timber and a concrete slab which were commonly connected together with inclined self-tapping screws(STSs).To more accurately predict the fire performance of TCC slabs,the mechanical behavior of TCC connections under high temperature was investigated by numerical simulation in this study.The interface slip of TCC connections was simulated by a proposed Finite Element(FE)model at room temperature,and different diameter and penetration length screws were considered.The effectiveness of this FE model was validated by comparing with the existing experimental results.Furthermore,the sequentially coupling thermal stress analyses of this model were conducted,and the relationship between the reduction coefficient of connection performance and the effective penetration length of screws was summarized.This study gave the fit-ting expressions for the reduction coefficient of slip modulus and joint strength.Finally,the numerical investiga-tions of the fire performance of TCC slabs considering the char fall-off of Cross Laminated Timber(CLT)were performed to verify the effectiveness of the proposed reduction law.Comparing the fire-resistance time with experimental results showed deviation of the proposed model was−14.02%.

Application of Modern Wood Product Glulam in Timber Frame With Tenon- Mortise Joints and Its Structural Behavior

Tenon-mortise joint is widely used in traditional timber structures around the world.This paper summarizes the results of an experimental study of the structural behavior of tenon-mortise joints made with glulam and CNC technology instead of traditional material and manual work.30 full-scale tenonmortise joints were manufactured and tested under monotonic loading,and the effects of dimension,shape,processing error and adhesive were evaluated.It was found that the round rectangular shaped tenon-mortise joints were comparable with traditional joints in terms of structural performance,but were time and labor saving.The variability of the proposed tenon-mortise joints was lower,which would benefit the design value.Applying adhesive between tenon and mortise increased the average stiffness by 4.3 times and average moment capacity by 27.4%,respectively.The gaps between wood members had little effect on the capacity and stiffness in monotonic bending but may influence the energy dissipation ability in cyclic bending.This study showed the feasibility of combining the traditional joinery method with modern wood products and manufacturing technology,which may promote the application of tenon-mortise joints in modern timber structures.

Frequencies Prediction of Laminated Timber Plates Using ANN Approach

Cross laminated timber(CLT)panels,which are used as load bearing plates and shear panels in timber structures,can serve as roofs,walls and floors.Since timber is construction material with relatively less stiffness,the design of such structures is often driven by serviceability criteria,such as deflection and vibration.Therefore,accurate vibration and elastic properties are vital for engineered CLT products.The objective of this research is to explore a method to determine the natural frequencies of orthotropic wood plates efficiently and fast.The method was developed based on vibration signal processing by wavelet to acquire the effective sample data,and a model developed by artificial neural network(ANN)to achieve the prediction of nature frequencies.First,experiments were performed to obtain vibration signals of single-layer plates.The vibration signals were then processed by wavelet packet transform to extract the eigenvectors,which served as the samples to train the ANN model.The trained model was employed to predict three nature frequencies of other test specimens.The results showed that the proposed method can produce predicted frequencies fast and efficiently within 10%of the measured values.

Measurement and Analysis of Three-Dimensional Surface Topography of Sawn Timber Based on Scanning Probe Method

In order to explore the characteristics of the three-dimensional surface morphology of sawn timber,a three-dimensional wood surface morphology tester based on the scanning probe method and the principle of atomic force microscope was used to test the three-dimensional sur face morphology of three kinds of sawn timber and calculate its surface roughness.This study also analyzed the reasonable plan for the value of wood surface roughness and the advantages of the three dimensional shape tester,as well as the influence of tree species,three sections,air dry density and other factors on the surface roughness of the specimen after mechanical processing.The results have shown that it is a more appropriate method to select the calculated values of S。and Sq as the evaluation of the surface roughness of wood with random surface characteristics.The three dimensional wood surface topo-graphy tester can efficiently,conveniently and accurately display the three dimensional topography of wood at a micron-level resolution,and is characterized by high eficiency and good durability.The three dimensional surface morphology characteristics of the three sawn woods correspond to their roughness.The surface roughness of woods is arranged as follows:Sitka spruce>Larch>Beech.For the same tree species,the roughness of the corresponding section after sawing is as follows:chordwise section>crosswise section>radial section.The radial section has lower roughness than the other surfaces.The surface roughness of the wood after sawing is mainly related to its air-dry density.The above is intended to provide a useful reference for the application of measuring and evaluating the surface roughness of sawn timber using the three dimensional surface topography test method.