In this paper, a concise and fast 2D model of the roll tensioning process was built using the finite element method. Elastic thermal expansion is used to simulate rolling plastic deformation. A 3D model considering contact between roller and circular saw blade was also built. Through comparison of residual stress results obtained by the 2D model, 3D model, and X-ray stress test method, the correctness and feasibility of the 2D model were proven. While accounting for the diversity of circular saw blade structure, this paper provided an idea for rapidly predicting the residual stress field of a roll-tensioned circular saw blade.
{"title":"An Idea for Predicting Residual Stress Field of Roll Tensioned Circular Saw Blade","authors":"Y. An, Bo Li, Boyang Zhang","doi":"10.13073/fpj-d-21-00017","DOIUrl":"https://doi.org/10.13073/fpj-d-21-00017","url":null,"abstract":"\u0000 In this paper, a concise and fast 2D model of the roll tensioning process was built using the finite element method. Elastic thermal expansion is used to simulate rolling plastic deformation. A 3D model considering contact between roller and circular saw blade was also built. Through comparison of residual stress results obtained by the 2D model, 3D model, and X-ray stress test method, the correctness and feasibility of the 2D model were proven. While accounting for the diversity of circular saw blade structure, this paper provided an idea for rapidly predicting the residual stress field of a roll-tensioned circular saw blade.","PeriodicalId":12387,"journal":{"name":"Forest Products Journal","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46487642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Khademibami, Alan Sherrington, R. Shmulsky, F. Quin
In this research, flexural properties of mill-run, in-grade red and white oak lumber from a single mill and commercially available laminated hardwood composite were evaluated. Structurally graded green (wet) freshly sawn red and white oak 5 by 10-cm (2 by 4-in) nominal lumber as well as glue-laminated hardwood composite billets were tested in bending and their modulus of rupture (MOR) and modulus of elasticity (MOE) properties were developed. It is well documented that MOR and MOE are two major indicators to evaluate flexural strength of wood lumbers. From these data, summary statistics, design values, and mean separations were calculated and reported. Overall, the red and white oak lumber performed similarly to structural No. 2 grade material. The hardwood composite billets were highly uniform. Each of the three materials demonstrated a reasonably good relationship between MOE and MOR, thereby suggesting that MOE could be used as a selection criterion for strength in a commercial use situation.
{"title":"Determination of Flexural Strength of Structural Red and White Oak and Hardwood Composite Lumber","authors":"L. Khademibami, Alan Sherrington, R. Shmulsky, F. Quin","doi":"10.13073/fpj-d-21-00051","DOIUrl":"https://doi.org/10.13073/fpj-d-21-00051","url":null,"abstract":"\u0000 In this research, flexural properties of mill-run, in-grade red and white oak lumber from a single mill and commercially available laminated hardwood composite were evaluated. Structurally graded green (wet) freshly sawn red and white oak 5 by 10-cm (2 by 4-in) nominal lumber as well as glue-laminated hardwood composite billets were tested in bending and their modulus of rupture (MOR) and modulus of elasticity (MOE) properties were developed. It is well documented that MOR and MOE are two major indicators to evaluate flexural strength of wood lumbers. From these data, summary statistics, design values, and mean separations were calculated and reported. Overall, the red and white oak lumber performed similarly to structural No. 2 grade material. The hardwood composite billets were highly uniform. Each of the three materials demonstrated a reasonably good relationship between MOE and MOR, thereby suggesting that MOE could be used as a selection criterion for strength in a commercial use situation.","PeriodicalId":12387,"journal":{"name":"Forest Products Journal","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47067376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Acoustic test methods such as longitudinal vibration have been developed to predict the elastic properties of wood. However, attention has not been shifted to using this method to predict other mechanical properties, especially on Nigeria's preferred, and lesser-used wood species. Thus, we further investigate relationships among mechanical and acoustic properties of selected hardwood species with a view of predicting the mechanical properties of wood from acoustic parameters. Clear wood samples (324) of 20 by 20 by 20 mm3 were collected axially from Albizia adianthifolia, Gmelina arborea, Delonix regia, and Boscia anguistifolia trees, and conditioned before testing. The longitudinal vibration method was adopted to test for the dynamic (acoustic) parameters and properties (fundamental frequency, damping factor, dynamic modulus of elasticity, sound velocity, specific elastic modulus, radiation coefficient, acoustic conversion efficiency, acoustic impedance) while the universal testing machine was used to test for the mechanical properties (static modulus of elasticity, modulus of rupture, maximum compression strength parallel to grain). The damping factor, dynamic modulus of elasticity, and acoustic impedance were the best acoustic parameters that significantly correlated with the static modulus of elasticity (−0.57, 0.81, 0.76), modulus of rupture −0.64, 0.82, 0.85) and maximum compression strength parallel to grain (−0.52, 0.78, 0.84), respectively. There was a significant difference in the mechanical properties with respect to species, thus A. adianthifolia and G. arborea were mechanically better than D. regia and B. anguistifolia for construction or structural purposes. This study revealed that additional new acoustic measures are suitable for inferring mechanical wood properties.
{"title":"Prediction of Mechanical Properties of Hardwood Species Using the Longitudinal Vibration Acoustic Method","authors":"K. Olaoye, L. Aguda, Bolade M. Ogunleye","doi":"10.13073/fpj-d-21-00048","DOIUrl":"https://doi.org/10.13073/fpj-d-21-00048","url":null,"abstract":"\u0000 Acoustic test methods such as longitudinal vibration have been developed to predict the elastic properties of wood. However, attention has not been shifted to using this method to predict other mechanical properties, especially on Nigeria's preferred, and lesser-used wood species. Thus, we further investigate relationships among mechanical and acoustic properties of selected hardwood species with a view of predicting the mechanical properties of wood from acoustic parameters. Clear wood samples (324) of 20 by 20 by 20 mm3 were collected axially from Albizia adianthifolia, Gmelina arborea, Delonix regia, and Boscia anguistifolia trees, and conditioned before testing. The longitudinal vibration method was adopted to test for the dynamic (acoustic) parameters and properties (fundamental frequency, damping factor, dynamic modulus of elasticity, sound velocity, specific elastic modulus, radiation coefficient, acoustic conversion efficiency, acoustic impedance) while the universal testing machine was used to test for the mechanical properties (static modulus of elasticity, modulus of rupture, maximum compression strength parallel to grain). The damping factor, dynamic modulus of elasticity, and acoustic impedance were the best acoustic parameters that significantly correlated with the static modulus of elasticity (−0.57, 0.81, 0.76), modulus of rupture −0.64, 0.82, 0.85) and maximum compression strength parallel to grain (−0.52, 0.78, 0.84), respectively. There was a significant difference in the mechanical properties with respect to species, thus A. adianthifolia and G. arborea were mechanically better than D. regia and B. anguistifolia for construction or structural purposes. This study revealed that additional new acoustic measures are suitable for inferring mechanical wood properties.","PeriodicalId":12387,"journal":{"name":"Forest Products Journal","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46776146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Naghizadeh, M. Pol, A. Alawode, M. Faezipour, G. Liaghat, B. Via, A. Abdolkhani
In this article, the behavior of wood, plywood, and oriented strand board (OSB) under high- and low-velocity impact loadings was investigated experimentally. For the high-velocity impact test, limit velocity (Vbl) and impact energy absorbed (Eab) were determined by subjecting the material to different impact loading by conical nose projectile. For the low-velocity impact test, the materials were subjected to four levels of energy—10, 39, 78, and 98 J—and the time history responses of velocity, energy, load, and displacement were obtained. Additionally, quantitative data for damage size are presented. The results show that in comparison with OSB and solid wood plates, plywood presents better characteristics in response to both high- and low-velocity impact loadings.
{"title":"Performance Comparison of Wood, Plywood, and Oriented Strand Board under High- and Low-Velocity Impact Loadings","authors":"Z. Naghizadeh, M. Pol, A. Alawode, M. Faezipour, G. Liaghat, B. Via, A. Abdolkhani","doi":"10.13073/fpj-d-21-00052","DOIUrl":"https://doi.org/10.13073/fpj-d-21-00052","url":null,"abstract":"\u0000 In this article, the behavior of wood, plywood, and oriented strand board (OSB) under high- and low-velocity impact loadings was investigated experimentally. For the high-velocity impact test, limit velocity (Vbl) and impact energy absorbed (Eab) were determined by subjecting the material to different impact loading by conical nose projectile. For the low-velocity impact test, the materials were subjected to four levels of energy—10, 39, 78, and 98 J—and the time history responses of velocity, energy, load, and displacement were obtained. Additionally, quantitative data for damage size are presented. The results show that in comparison with OSB and solid wood plates, plywood presents better characteristics in response to both high- and low-velocity impact loadings.","PeriodicalId":12387,"journal":{"name":"Forest Products Journal","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47251330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Despite the sustained interest in multistory wood-frame construction (WMC) along with an expanding bioeconomy, the rate of market uptake has been modest outside North America. Changing environmental values and regulation are expected to boost WMC adoption along with an expanding bioeconomy, yet the future prospects of WMC are typically explored with an empirical focus on the actors that are already active in WMC. To address the possible bias, this paper elicits the views of nonwood actors (i.e., construction company managers and executives in the areas of procurement and project planning with no prior experience in WMC), through 10 semistructured interviews. The results indicate that the nonwood actors do not necessarily oppose WMC as such, but there remain competitive barriers for a major market growth of WMC related to, for example, lack of standardization and significant enough productivity benefits to motivate adopting a new potentially risky construction practice. Based on comparisons with previous literature, the most notable differences in opinions between wood actors and nonwood actors regarded the direction and strength of the impact of consumer preferences on WMC demand. While acknowledging that this is a crude comparison without statistical significance, one can observe similarities in the distribution of answers for the questions unrelated to WMC, but more dispersion for those addressing WMC. Yet, while the attitudes toward wood as a construction material seem to differ, both the wood and nonwood actors seem to regard the doubling of the market share of WMC in Finland by 2030 as feasible.
{"title":"What About Wood?—“Nonwood” Construction Experts' Perceptions of Environmental Regulation, Business Environment, and Future Trends in Residential Multistory Building in Finland","authors":"Aleksi Aaltonen, Elias Hurmekoski, J. Korhonen","doi":"10.13073/fpj-d-21-00033","DOIUrl":"https://doi.org/10.13073/fpj-d-21-00033","url":null,"abstract":"\u0000 Despite the sustained interest in multistory wood-frame construction (WMC) along with an expanding bioeconomy, the rate of market uptake has been modest outside North America. Changing environmental values and regulation are expected to boost WMC adoption along with an expanding bioeconomy, yet the future prospects of WMC are typically explored with an empirical focus on the actors that are already active in WMC. To address the possible bias, this paper elicits the views of nonwood actors (i.e., construction company managers and executives in the areas of procurement and project planning with no prior experience in WMC), through 10 semistructured interviews. The results indicate that the nonwood actors do not necessarily oppose WMC as such, but there remain competitive barriers for a major market growth of WMC related to, for example, lack of standardization and significant enough productivity benefits to motivate adopting a new potentially risky construction practice. Based on comparisons with previous literature, the most notable differences in opinions between wood actors and nonwood actors regarded the direction and strength of the impact of consumer preferences on WMC demand. While acknowledging that this is a crude comparison without statistical significance, one can observe similarities in the distribution of answers for the questions unrelated to WMC, but more dispersion for those addressing WMC. Yet, while the attitudes toward wood as a construction material seem to differ, both the wood and nonwood actors seem to regard the doubling of the market share of WMC in Finland by 2030 as feasible.","PeriodicalId":12387,"journal":{"name":"Forest Products Journal","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44668253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Manisha Parajuli, Patrick Hiesl, M. Smidt, D. Mitchell
In the Southern United States, a rising number of biomass facilities have created new market opportunities for forest landowners, consulting foresters, and loggers, which could increase the competition between the biomass market and pulpwood market for forest biomass. Thus, comparing the profits from conventional roundwood harvesting and biomass harvesting within a range of procurement distances could be crucial to make a harvest decision. In this study, we considered two harvesting systems: conventional and biomass. We developed a decision support tool to predict and compare the final stumpage value from both harvesting systems based on the stand and site conditions, market conditions, and distance to the nearest market. We grew (simulated) loblolly pine (Pinus taeda) plantations to six different thinning ages (12, 14, 16, 18, 20, and 22 yr) at five different site indices (17, 20, 23, 26, and 29 m at a base age of 25 yr) using the PTAEDA4.0 software. Different models were fitted and evaluated for certain training and validating criteria. In both harvesting systems, we select the cube root-transformed model as the best model. Using the models, we predict that the utilization of logging residues and pulpwood as wood chips may yield a higher return to the landowner when the delivered price of the wood chips is comparable to the delivered price of the pulpwood and within the same procurement distance. The selected models thus serve as a decision support tool to inform stakeholders to further maximize their economic return from timber harvesting operations by selecting the most profitable option.
{"title":"An Evaluation of Woody Biomass and Pulpwood Market Competition within a Range of Procurement Distances","authors":"Manisha Parajuli, Patrick Hiesl, M. Smidt, D. Mitchell","doi":"10.13073/fpj-d-21-00032","DOIUrl":"https://doi.org/10.13073/fpj-d-21-00032","url":null,"abstract":"\u0000 In the Southern United States, a rising number of biomass facilities have created new market opportunities for forest landowners, consulting foresters, and loggers, which could increase the competition between the biomass market and pulpwood market for forest biomass. Thus, comparing the profits from conventional roundwood harvesting and biomass harvesting within a range of procurement distances could be crucial to make a harvest decision. In this study, we considered two harvesting systems: conventional and biomass. We developed a decision support tool to predict and compare the final stumpage value from both harvesting systems based on the stand and site conditions, market conditions, and distance to the nearest market. We grew (simulated) loblolly pine (Pinus taeda) plantations to six different thinning ages (12, 14, 16, 18, 20, and 22 yr) at five different site indices (17, 20, 23, 26, and 29 m at a base age of 25 yr) using the PTAEDA4.0 software. Different models were fitted and evaluated for certain training and validating criteria. In both harvesting systems, we select the cube root-transformed model as the best model. Using the models, we predict that the utilization of logging residues and pulpwood as wood chips may yield a higher return to the landowner when the delivered price of the wood chips is comparable to the delivered price of the pulpwood and within the same procurement distance. The selected models thus serve as a decision support tool to inform stakeholders to further maximize their economic return from timber harvesting operations by selecting the most profitable option.","PeriodicalId":12387,"journal":{"name":"Forest Products Journal","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49172624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An-Hong Zhu, Shiming Ren, Xueqi Li, Xiaoqi Zhao, Lei Wang, Minzhen Bao, Yamei Wang
Chinese medicine herbal extracts are ideal candidates to replace toxic industrial wood preservatives thanks to their antifungal and nontoxic properties. To investigate the antifungal activity of Chinese herbal medicines, in this study, Trametes versicolor fungi were selected as test strains to evaluate the antifungal properties of Fructus Cnidii, Fructus Forsythiae, and Radix Stemonae. The results show that Fructus Cnidii has a strong inhibitory effect against T. versicolor, whereas Fructus Forsythiae and Radix Stemonae have a weak inhibitory effect. The hyphae growth cycle shows that the three studied Chinese herbs disrupt the growth of T. versicolor. Moreover, instead of direct killing, the Chinese herbal medicine demonstrated inhibition ability. Furthermore, the morphological and toxicological evidence shows that Fructus Cnidii affected the expression of proteins or enzymes to achieve the inhibition goal. In sum, this study could provide both primary data and a theoretical foundation for further developing and applying for traditional Chinese medicine as a green type of wood preservative.
{"title":"Study of Antifungal Activity Using Three Chinese Medicine Herbs","authors":"An-Hong Zhu, Shiming Ren, Xueqi Li, Xiaoqi Zhao, Lei Wang, Minzhen Bao, Yamei Wang","doi":"10.13073/fpj-d-21-00027","DOIUrl":"https://doi.org/10.13073/fpj-d-21-00027","url":null,"abstract":"\u0000 Chinese medicine herbal extracts are ideal candidates to replace toxic industrial wood preservatives thanks to their antifungal and nontoxic properties. To investigate the antifungal activity of Chinese herbal medicines, in this study, Trametes versicolor fungi were selected as test strains to evaluate the antifungal properties of Fructus Cnidii, Fructus Forsythiae, and Radix Stemonae. The results show that Fructus Cnidii has a strong inhibitory effect against T. versicolor, whereas Fructus Forsythiae and Radix Stemonae have a weak inhibitory effect. The hyphae growth cycle shows that the three studied Chinese herbs disrupt the growth of T. versicolor. Moreover, instead of direct killing, the Chinese herbal medicine demonstrated inhibition ability. Furthermore, the morphological and toxicological evidence shows that Fructus Cnidii affected the expression of proteins or enzymes to achieve the inhibition goal. In sum, this study could provide both primary data and a theoretical foundation for further developing and applying for traditional Chinese medicine as a green type of wood preservative.","PeriodicalId":12387,"journal":{"name":"Forest Products Journal","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44523999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Azadwinder Chahal, J. Tripathi, D. Ciolkosz, S. Wurzbacher, Michael Jacobson
Sufficiently valuing small-diameter-stem (diameter < 9 in.) woody material in Pennsylvania forest product markets may incentivize increased utilization of that material, a resource opportunity that would provide economic and ecological benefits to the state's forests and forest products community. Debarking is one primary process that could enhance the value of these small-diameter-stem materials for secondary markets. The wood products community in Pennsylvania was surveyed as to their perceptions of the status and value of economical small-diameter-stem debarking. The largest perceived current market for debarked, small-diameter-stem material identified by respondents is for chips for pulp and paper, and anticipated future demand is expected to be highest for chips for pulp and paper, chips for energy, and small-dimension lumber. Respondents who currently supply a given market tend to be more optimistic about that market than respondents who do not serve that particular market. Shredded wood/hog fuel and mulch are the two markets with the lowest overall scores for anticipated benefit of additional processing by debarking. Seventy-six percent of all respondents indicated that economical small-diameter-stem debarking would benefit their operation.
{"title":"Perceptions of Debarking Small-Diameter Stems in the Wood Products Community","authors":"Azadwinder Chahal, J. Tripathi, D. Ciolkosz, S. Wurzbacher, Michael Jacobson","doi":"10.13073/fpj-d-20-00074","DOIUrl":"https://doi.org/10.13073/fpj-d-20-00074","url":null,"abstract":"\u0000 Sufficiently valuing small-diameter-stem (diameter < 9 in.) woody material in Pennsylvania forest product markets may incentivize increased utilization of that material, a resource opportunity that would provide economic and ecological benefits to the state's forests and forest products community. Debarking is one primary process that could enhance the value of these small-diameter-stem materials for secondary markets. The wood products community in Pennsylvania was surveyed as to their perceptions of the status and value of economical small-diameter-stem debarking. The largest perceived current market for debarked, small-diameter-stem material identified by respondents is for chips for pulp and paper, and anticipated future demand is expected to be highest for chips for pulp and paper, chips for energy, and small-dimension lumber. Respondents who currently supply a given market tend to be more optimistic about that market than respondents who do not serve that particular market. Shredded wood/hog fuel and mulch are the two markets with the lowest overall scores for anticipated benefit of additional processing by debarking. Seventy-six percent of all respondents indicated that economical small-diameter-stem debarking would benefit their operation.","PeriodicalId":12387,"journal":{"name":"Forest Products Journal","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45368479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The metrological verification of log scanners requires logs with accurately known dimensions as test objects. The measurement of the lengths and diameters must be traceable back to the SI (International System of Units) unit of length. The results have to be reported with the corresponding measurement uncertainties. The uncertainties are required to be 5 to 10 times lower than the corresponding maximum permissible errors allowed for the log scanner under test. This article presents a procedure for the reference measurement of logs using an off-the-shelf fringe projection system along with uncertainty budgets for the measured dimensions. The length and diameters are determined from the highly resolved mesh obtained by fringe projection using techniques from computational geometry and coordinate metrology. Corrections are applied to the length and diameter values to remove the systematic effect caused by scattering of projected light below the partially transparent log surface. The influence of the fringe projection system on the measured dimensions is determined by measurements of calibrated artifacts, which also provide the traceability back to the SI unit of length. The measurement is illustrated by the example of a log with a length of 2 m and a diameter of 280 mm. The corresponding uncertainty budgets, confirmed by repeat measurements, result in expanded uncertainties (confidence interval 95%) of 6 mm and 0.13 mm for length and diameter, respectively. These low values qualify the fringe projection measurement along with accompanying evaluation procedure to provide logs as reference objects for the verification of log scanners.
{"title":"Reference Measurement of Roundwood by Fringe Projection","authors":"C. Keck, R. Schödel","doi":"10.13073/fpj-d-21-00024","DOIUrl":"https://doi.org/10.13073/fpj-d-21-00024","url":null,"abstract":"\u0000 The metrological verification of log scanners requires logs with accurately known dimensions as test objects. The measurement of the lengths and diameters must be traceable back to the SI (International System of Units) unit of length. The results have to be reported with the corresponding measurement uncertainties. The uncertainties are required to be 5 to 10 times lower than the corresponding maximum permissible errors allowed for the log scanner under test. This article presents a procedure for the reference measurement of logs using an off-the-shelf fringe projection system along with uncertainty budgets for the measured dimensions. The length and diameters are determined from the highly resolved mesh obtained by fringe projection using techniques from computational geometry and coordinate metrology. Corrections are applied to the length and diameter values to remove the systematic effect caused by scattering of projected light below the partially transparent log surface. The influence of the fringe projection system on the measured dimensions is determined by measurements of calibrated artifacts, which also provide the traceability back to the SI unit of length. The measurement is illustrated by the example of a log with a length of 2 m and a diameter of 280 mm. The corresponding uncertainty budgets, confirmed by repeat measurements, result in expanded uncertainties (confidence interval 95%) of 6 mm and 0.13 mm for length and diameter, respectively. These low values qualify the fringe projection measurement along with accompanying evaluation procedure to provide logs as reference objects for the verification of log scanners.","PeriodicalId":12387,"journal":{"name":"Forest Products Journal","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48422373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chenshan red-heart Chinese fir is a provenance of Cunninghamia lanceolata, with high-value red heartwood, which is widely used in high-quality furniture and construction. Yet, there is still little information on heartwood development of this tree for high-value decorative timber, which is essential to improve one's plantation management strategy. Here, we investigated the horizontal and vertical variation of heartwood and sapwood and simulated heartwood formation process using stem analysis method. We selected 15 sample trees from five plots of 20 m × 30 m in Chenshan red-heart Chinese fir plantations (9, 15, 26, 29, and 34 years old, respectively). The results showed that Chenshan red-heart Chinese fir stems began to form heartwood when the xylem diameter reached 4 to 8 cm. The heartwood diameter and area, as well as the sapwood area, all increased in the different-aged Chenshan red-heart Chinese firs with increasing xylem diameter and decreased with increasing tree height. As tree height increased, the red heartwood formation rate declined at all ages. Relationship analysis showed that xylem diameter was the most important factor influencing heartwood formation. Red heartwood rate at breast height could be modeled by logistic models. We concluded that heartwood formation began at about 7 years old, and the formation rate increased until peaking at 60 percent at 40 years old. In conclusion, it will be imperative to prolong the Chenshan red-heart Chinese fir rotation period from the currently common 25 years to about 40 years to achieve the maximum sustainable yield of high-value decorative timber.
陈山红心杉木是杉木的种源，具有高价值的红心材，广泛用于优质家具和建筑。然而，关于这种树作为高价值装饰木材的心材开发的信息仍然很少，这对改善人工林管理策略至关重要。本文采用茎干分析方法，研究了心材和边材的水平和垂直变化，模拟了心材的形成过程。选取陈山红心杉木人工林5块样地，面积为20 m × 30 m，分别为9、15、26、29和34年树龄，共15棵。结果表明，陈山红心杉木茎在木质部直径达到4 ~ 8 cm时开始形成心材。不同树龄陈山红心杉木的心材直径、面积和边材面积均随木质部直径的增加而增加，随树高的增加而减少。随着树高的增加，红心材形成率在各年龄段均呈下降趋势。关系分析表明，木质部直径是影响心材形成的最重要因素。胸高红心材率可用logistic模型建模。我们得出结论，心材的形成始于7岁左右，形成率逐渐增加，在40岁时达到60%的峰值。综上所述，为了实现高价值装饰木材的最大可持续产量，必须将陈山红心杉木的轮作周期从目前常见的25年延长到40年左右。
{"title":"Heartwood and Sapwood Variation and Development in Chenshan Red-Heart Chinese Fir (Cunninghamia lanceolata (Lamb.) Hook)","authors":"Huiling Kang, X. Wen, X. Deng, Liang Chen, Fuming Xiao","doi":"10.13073/fpj-d-21-00034","DOIUrl":"https://doi.org/10.13073/fpj-d-21-00034","url":null,"abstract":"\u0000 Chenshan red-heart Chinese fir is a provenance of Cunninghamia lanceolata, with high-value red heartwood, which is widely used in high-quality furniture and construction. Yet, there is still little information on heartwood development of this tree for high-value decorative timber, which is essential to improve one's plantation management strategy. Here, we investigated the horizontal and vertical variation of heartwood and sapwood and simulated heartwood formation process using stem analysis method. We selected 15 sample trees from five plots of 20 m × 30 m in Chenshan red-heart Chinese fir plantations (9, 15, 26, 29, and 34 years old, respectively). The results showed that Chenshan red-heart Chinese fir stems began to form heartwood when the xylem diameter reached 4 to 8 cm. The heartwood diameter and area, as well as the sapwood area, all increased in the different-aged Chenshan red-heart Chinese firs with increasing xylem diameter and decreased with increasing tree height. As tree height increased, the red heartwood formation rate declined at all ages. Relationship analysis showed that xylem diameter was the most important factor influencing heartwood formation. Red heartwood rate at breast height could be modeled by logistic models. We concluded that heartwood formation began at about 7 years old, and the formation rate increased until peaking at 60 percent at 40 years old. In conclusion, it will be imperative to prolong the Chenshan red-heart Chinese fir rotation period from the currently common 25 years to about 40 years to achieve the maximum sustainable yield of high-value decorative timber.","PeriodicalId":12387,"journal":{"name":"Forest Products Journal","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41995243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：