Zeitschriftenartikel: „Bent wood“

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Demitrova, I., und O. Saveleva. „Production of bent furniture from massive wood“. Актуальные направления научных исследований XXI века: теория и практика 3, Nr. 5 (02.12.2015): 456–58. http://dx.doi.org/10.12737/16300.

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Wilson, Brayton F. „Response to stem bending in forest shrubs: stem or shoot reorientation and shoot release“. Canadian Journal of Botany 75, Nr. 10 (01.10.1997): 1643–48. http://dx.doi.org/10.1139/b97-876.

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Shrubs in the forest understory may be bent by their own weight or by overstory debris. To maintain height growth they must respond to bending by vertical growth of new shoots, reorientation of older axes, or by releasing preventitious buds to form epicormic shoots. I tested for these responses in Ilex verticillata L., Cornus amomum Mill., Gaylussacia baccata (Wang.) K. Koch, Viburnum cassinoides L., Hamamelis virginiana L., and Kalmia latifolia L. For each species, I removed potentially supporting vegetation adjacent to 20 stems, left 10 stems untreated to test for bending by self weight, and bent the remaining 10 stems to 45° to simulate effects of fallen debris. Stem angles and curvatures were measured from before leaf out until just before leaf fall to detect either sagging from self weight or upward bending from tension wood action. Control stems initially leaned out of vertical and five of six species sagged further into a cantilever form. Several control stems failed and bent to the ground. Stems of H. virginiana, I. verticillata, and C. amomum formed tension wood, but only the first two species bent upward. Viburnum cassinoides, G. baccata, and K. latifolia formed no tension wood and sagged further down after being bent. Epicormic shoots formed with varying frequencies in all species except K. latifolia. Epicormic shoots were the major response in C. amomum, V. cassinoides, and G. baccata. New terminal shoots on bent stems recovered toward vertical in I. verticillata and K. latifolia. Negative gravitropic response of shoots was the only recovery mechanism for K. latifolia. Key words: forest shrubs, tension wood, epicormic shoots, bending, stem architecture.

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Lachaud, Suzanne. „Xylogénèse chez les Dicotylédones arborescentes. V. Formation du bois de tension et transport de l'acide indole acétique tritié chez le Hêtre“. Canadian Journal of Botany 65, Nr. 6 (01.06.1987): 1253–58. http://dx.doi.org/10.1139/b87-174.

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Upper stems of young beeches (Fagus silvatica L.) were bent into Jaccard loops in May. If they stayed on the tree, they produced a wide arc of extreme tension wood on the upper side of the loop, which contained numerous gelatinous fibers, few vessels, and little axial parenchyma. On the lower side of these loops, xylogenesis was nearly stopped. If bent stems were removed from the tree, xylogenesis was far less asymmetric: the wood formed on the upper side contained normal vessels and axial parenchyma, but also gelatinous fibers; on the lower side, the wood was normal. Transport and metabolism of 3H-labelled indole acetic acid was studied in both models. In intact loops left on the trees, lateral auxin transport took place mainly towards the lower half of the stem. In isolated loops, no preferential direction could be detected for lateral auxin transport. Extreme tension wood differentiation on the upper side of a bent stem requires the intervention of correlative factors, not only from buds, but also from the base of the tree, which particularly influence lateral downward transport of auxin.

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Yeh, Ting-Feng, Jennifer L. Braun, Barry Goldfarb, Hou-min Chang und John F. Kadla. „Morphological and chemical variations between juvenile wood, mature wood, and compression wood of loblolly pine (Pinus taeda L.)“. Holzforschung 60, Nr. 1 (01.01.2006): 1–8. http://dx.doi.org/10.1515/hf.2006.001.

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Abstract To better understand the within-tree variations between juvenile wood, mature wood, and compression wood, wood from a 35-year-old mature bent loblolly pine was separated into seven groups by different positions in the tree. Morphological and chemical structure analyses, including fiber quality, X-ray diffraction, sugar and lignin content analysis, as well as nitrobenzene oxidation, ozonation, and advanced NMR spectroscopy, were performed. Fiber properties were significantly different for tree-top juvenile normal wood and tree-bottom juvenile normal wood, juvenile normal and mature normal wood, juvenile compression and mature compression wood. However, differences in the chemical structure and composition were less significant within the specific tissues indicated above.

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Boymatov, Fakhridin, und Nikolay Nazarenko. „Working capability of composite wood-rubcon (rubber concrete) reinforced bridge beams under static loads“. E3S Web of Conferences 164 (2020): 08025. http://dx.doi.org/10.1051/e3sconf/202016408025.

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The results of experimental studies of the performance of bent composite wood-rubcon reinforced bridge beams under static loads are presented and the bearing capacity of composite wood-rubcon reinforced bridge beams is determined. A method for calculating wood-rubcon reinforced composite bridge beams is proposed.

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Abedini, Raoufeh, Bruno Clair, Kambiz Pourtahmasi, Françoise Laurans und Olivier Arnould. „Cell wall thickening in developing tension wood of artificially bent poplar trees“. IAWA Journal 36, Nr. 1 (18.03.2015): 44–57. http://dx.doi.org/10.1163/22941932-00000084.

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Trees can control their shape and resist gravity thanks to their ability to produce wood under tensile stress. This stress is known to be produced during the maturation of wood fibres but the mechanism of its generation remains unclear. This study focuses on the formation of the secondary wall in tension wood produced in artificially tilted poplar saplings. Thickness of secondary wall layer (SL) and gelatinous layer (GL) were measured from cambium to mature wood in several trees sampled at different times after tilting. Measurements on wood fibres produced before tilting show the progressive increase of secondary wall thickness during the growing season. After the tilting date, SL thickness decreased markedly from normal wood to tension wood while the total thickness increased compared to normal wood, with the development of a thick GL. However, even after GL formation, SL thickness continues to increase during the growing season. GL thickening was observed to be faster than SL thickening. The development of the unlignified GL is proposed to be a low cost, efficient strategy for a fast generation of tensile stress in broadleaved trees.

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Jourez, B., A. Riboux und A. Leclercq. „Comparison of basic density and longitudinal shrinkage in tension wood and opposite wood in young stems of Populus euramericana cv. Ghoy when subjected to a gravitational stimulus“. Canadian Journal of Forest Research 31, Nr. 10 (01.10.2001): 1676–83. http://dx.doi.org/10.1139/x01-096.

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In a greenhouse, under controlled conditions, young shoots, taken from poplar cuttings (Populus euramericana (Dole) Guinier cv. Ghoy), were artificially bent to quantify the modifications of physical properties induced by a gravitational stimulus. At the end of the growing season, basic density and longitudinal shrinkage were measured on very small samples taken from pure tension wood tissue observed on the upper face of the inclined axis and compared with opposite wood tissue, free of gelatinous fibers, developed on the opposite lower face. In a second step, shoots bent at two different lean intensities were analyzed. In young poplar wood, gravitational stimulus was found to have a significant effect on physical properties. Relations between basic density and longitudinal shrinkage are different depending on the types of wood considered. Shrinkage appears more sensitive to lean intensity in the range considered here.

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Li, Xinguo, Robert Evans, Washington Gapare, Xiaohui Yang und Harry X. Wu. „Characterizing compression wood formed in radiata pine branches“. IAWA Journal 35, Nr. 4 (06.12.2014): 385–94. http://dx.doi.org/10.1163/22941932-00000073.

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The formation of reaction wood is an adaptive feature of trees in response to various mechanical forces. In gymnosperms, reaction wood consists of compression wood (CW) and opposite wood (OW) that are formed on the underside and upperside of bent trunks and branches. Although reaction wood formed in bent trunks has been extensively investigated, relatively little has been reported from conifer branches. In this study SilviScan® technology was used to characterize radiata pine branches at high resolution. Compared to OW formed in the branches, CW showed greater growth, darker colour, thicker tracheid walls, higher coarseness, larger microfibril angle (MFA), higher wood density, lower extensional stiffness and smaller internal specific surface area. However, tracheids of CW were similar to those of OW in their radial and tangential diameters. These results indicated that gravity influenced tracheid cell division and secondary wall formation but had limited impact on primary wall expansion. Furthermore, seasonal patterns of CW formation were not observed in the branches from cambial age 4 while earlywood and latewood were clearly separated in all rings of OW. The marked change of MFA during reaction wood formation suggested that branches could be ideal materials for further study of cellulose microfibril orientation.

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Fredericksen, T. S., R. L. Hedden und S. A. Williams. „Effect of stem bending on hydraulic conductivity and wood strength of loblolly pine“. Canadian Journal of Forest Research 24, Nr. 3 (01.03.1994): 442–46. http://dx.doi.org/10.1139/x94-060.

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Stems of 30-year-old loblolly pine (Pinustaeda L.) trees were bent with a winch to determine the effect of bending, which might occur from severe wind stress, on the hydraulic conductivity and wood strength of tree stems. Stems were bent to a point of imminent stem failure and then released. After release, stems leaned an average of 6.25° from their original vertical position. Measurements of sapwood permeability and viable conducting area were made on stem sections cut from bent trees and were compared with sections taken from unstressed (control) trees. Dye was used to determine the percentage of functional conducting elements. An average loss of approximately 30% in conducting sapwood area was attributed to the bending treatment. Loss of functional conducting area was greater along the axis of bending than on the lateral sides of the stem perpendicular to the direction of bending. Damage was greatest on the compression side of the stem. Despite this damage, no difference was observed in sapwood permeability due to treatment. Modulus of elasticity and modulus of rupture were reduced by 19% and 34%, respectively, on the compression side of bent stems compared with control stems. Loblolly pine appears to be capable of sustaining significant damage to its water conducting system without compromising its hydraulic conductivity. However, reduced wood strength due to bending may result in increased susceptibility to wind breakage and (or) decreased commercial value.

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Storodubtseva, Tamara, I. Andreyscheva und A. Shatalova. „COLOR RANGE OF WOOD AND HUMAN PRODUCTS“. Actual directions of scientific researches of the XXI century: theory and practice 8, Nr. 1 (26.10.2020): 149–52. http://dx.doi.org/10.34220/2308-8877-2020-8-1-149-152.

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The article considers the psycho-emotional state of a person, which depends on the surrounding furniture, in this case, on its color scheme. Wood surrounds us everywhere and always, how does it affect us? Which wood is better in structure, in ease of production? What are the qualities of wood? And the main question is, what effect does wood furniture of different species have on us and how does it affect our health? We tried to find out these questions in our article. For the manufacture of furniture, it is necessary to use wood of a thin structure, which can be subjected to processing and apply a beautiful finish. Oak wood is suitable for the manufacture of bent furniture. It has large vessels and is well bent due to large vessels, while the wood fibers are not destroyed. At the end of the first year, students of the Forestry Faculty with a profile in furniture design and woodworking technology undergo practical training in the Vosmodrev workshop, gaining maximum knowledge about wood as a material for the manufacture of various types of products, processing and processing - production technologies. A very important factor is the color scheme, which is selected by the creators of the latest examples of the furniture industry for the emotional state of a person. It is important to consider which color causes which emotion - positive or negative.

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Bai, Xuejiao, und Minchen Bao. „Structural Analysis and Optimization Design of Laminated Bent-wood Chair“. IOP Conference Series: Earth and Environmental Science 242 (30.03.2019): 062064. http://dx.doi.org/10.1088/1755-1315/242/6/062064.

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Wilson, Brayton F., und Barbara L. Gartner. „Lean in red alder (Alnusrubra): growth stress, tension wood, and righting response“. Canadian Journal of Forest Research 26, Nr. 11 (01.11.1996): 1951–56. http://dx.doi.org/10.1139/x26-220.

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Natural stands and a 3-year-old plantation of red alder (Alnusrubra Bong.) trees were used to study the incidence of leaning stems, the level of growth stresses and tension wood formation, and the ability of the stems to right themselves to vertical. Overall, 10% of the 512 trees in 10 natural stands leaned >22°. The largest diameter trees on the steepest slopes leaned most. Most (61%) of the trees curved upward, showing a righting response. For samples without tension wood, growth stress levels on the upper side of leaning stems, but not on the lateral or lower sides, were positively correlated with lean angles above 6°. These leaning stems had a significant righting response without tension wood. Tension wood formation was variable at leans from 9° to 26° both within and among trees, but was correlated with eccentric growth rings. We measured stem recovery in the year-old stem of 3-year-old trees bent to angles of 0–37.5°. During the 5-month experiment all stems righted to near vertical. Tension wood formed on the upper side in stems bent >6°, but reversed to the lower side before reaching vertical in 22 of 30 trees.

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Famulyak, Yu, B. Demchyna und Kh Demchyna. „Investigation of bearing capacity and deformability of bent wood-concrete beams“. Vìsnik L’vìvs’kogo nacìonal’nogo agrarnogo unìversitetu. Arhìtektura ì sìl’s’kogospodars’ke budìvnictvo 19 (01.12.2018): 61–69. http://dx.doi.org/10.31734/architecture2018.19.061.

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Kolesnikov, G. N., O. A. Kunitskaya, I. V. Grigorev, M. V. Stepanischeva und A. O. Bormatenko. „Modeling of stresses and deformations of bark of bent long wood“. Systems. Methods. Technologies, Nr. 2(34) (2017): 105–8. http://dx.doi.org/10.18324/2077-5415-2017-2-105-108.

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Kawecki, Bartosz, und Jerzy Podgórski. „The Effect of Glue Cohesive Stiffness on the Elastic Performance of Bent Wood–CFRP Beams“. Materials 13, Nr. 22 (11.11.2020): 5075. http://dx.doi.org/10.3390/ma13225075.

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This paper presents experimental, theoretical and numerical studies of wood-CFRP beams bonded with polyurethane (PUR) adhesive. The analyses include two types of CFRP (carbon fibre-reinforced polymer) strengthening configurations and pure glue laminated timber beams as a reference. Through detailed analyses of a double-lap connection on blocks with and without CFRP strips, the authors state that neglecting the cohesive stiffness of adhesive layers may lead to an overestimation of an overall beam’s stiffness. This is significant with wood–CFRP connections, which showed values two times lower than with wood–wood connections. Theoretical modelling of the equivalent area used in a theory of composites provided much stiffer behaviour of the beams than in laboratory experiments. It proves that a PUR glue eliminates the possibility of using simple models that assume a perfect connection between bonded parts. These conclusions led the authors to use the finite element method (FEM) to take into account the cohesive stiffness. The FEM, based on the properties obtained from a double-lap joint analysis, allowed for the precise prediction of the elastic stiffness of the beams.

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Büyüksarı, Ümit, und Nusret As. „Non-destructive evaluation of beech and oak wood bent at different radii“. Composites Part B: Engineering 48 (Mai 2013): 106–10. http://dx.doi.org/10.1016/j.compositesb.2012.12.006.

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As, Nusret, Daniel Hindman und Ümit Büyüksarı. „The effect of bending parameters on mechanical properties of bent oak wood“. European Journal of Wood and Wood Products 76, Nr. 2 (18.02.2017): 633–41. http://dx.doi.org/10.1007/s00107-017-1162-2.

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Wdowiak, Agnieszka, und Janusz Brol. „Effectiveness of Reinforcing Bent Non-Uniform Pre-Stressed Glulam Beams with Basalt Fibre Reinforced Polymers Rods“. Materials 12, Nr. 19 (26.09.2019): 3141. http://dx.doi.org/10.3390/ma12193141.

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The article presents the testing designating the impact of structural non-uniformity on the effectiveness of reinforcing bent wooden beams reinforced with basalt fibre (BFRP—Basalt Fibre Reinforced Polymers) rods. The obtained results demonstrate a positive impact of the strengthening in improving the bearing capacity and rigidness of the wooden beams. The article presents the impact of selected physical and chemical properties of wooden elements on the achieved strengthening reliability, increase in bearing capacity and the estimation of the reduction of deflections and stresses of bent beams, made from various wood quality classes and reinforced using BFRP rods. The conducted testing featured an analysis of the ability of using lower quality class lumber to strengthen the beams with pre-stressed basalt fibre rods. This solution allows for reducing the cross-section or lower the class of used wood with simultaneous maintenance of comparable rigidity and bending strength of beams, as in the non-strengthened beams.

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Wang, Yu, Suri Gala und Jin Tian Huang. „Fabrication of flexible thin veneer for electromagnetic interference shielding and decoration through simple electroless plating“. BioResources 15, Nr. 3 (05.06.2020): 5737–48. http://dx.doi.org/10.15376/biores.15.3.5737-5748.

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A widely applicable electromagnetic interference (EMI) shielding and decorative thin veneer containing copper was prepared with simple electroless technology. Copper was used as the structural and EMI reflection component to reinforce the mechanical strength and EMI shielding effectiveness. Both the texture and structural properties of copper deposited on poplar wood were characterized. The X-ray diffraction patterns indicated that the copper deposited on poplar wood had a crystallite size between 7.9 nm and 15.9 nm, and the copper crystallites grew rapidly as the number of electroless runs increased, which was consistent with the resistivity and microscopy analyses. The mechanical and EMI shielding effectiveness results showed that after two electroless runs, the wood veneer surface was completely covered, which improved the EMI shielding effectiveness and mechanical properties of wood veneer. The material could be bent 360° without being damaged and had a good decorative effect.

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Molinski, Waldemar, Jan Raczkowski und Lech Muszynski. „Acoustic Emission Generated upon Mechano-Sorptive Creep of Wood Bent Across to the Grain under Asymmetrical Moistening“. Holzforschung 54, Nr. 3 (13.04.2000): 305–8. http://dx.doi.org/10.1515/hf.2000.051.

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Summary Acoustic emission (AE) generated in pine wood samples upon bending across the grain under simultaneous moistening of the tension zone, was measured. The aim of the study was to determine the effect of external tension load on AE generated during asymmetrical moistening of dry wood samples in water. The cumulative counts of AE signals recorded during simultaneous moistening of the tension zone of sample were proportional to the intensity of the mechano-sorptive strain. AE starts when the mechano-sorptive strain in the tension zone (εT) reaches a value close to 0.8%.

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Mania, Przemysław, und Mateusz Gąsiorek. „Acoustic Properties of Resonant Spruce Wood Modified Using Oil-Heat Treatment (OHT)“. Materials 13, Nr. 8 (22.04.2020): 1962. http://dx.doi.org/10.3390/ma13081962.

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Wedge-shaped boards of spruce wood (Picea abies Karst.) are used to make violin fronts, also known as soundboards. Oil-heat treatment (OHT) can influence the acoustic properties of resonant wood, such as spruce. In this study, the effect of OHT on spruce wood was evaluated, using palm oil as a heating medium, at four different temperatures: 140, 160, 180 and 200 °C. Physical, mechanical and acoustic properties of spruce wood were evaluated before and after OHT and included the following: density, modulus of elasticity in the static bending test, and wood sound velocity. The acoustic parameters after OHT improved; however, the samples bent after modification had a higher modulus of elasticity, with a simultaneous deterioration of the acoustic parameters. The dynamic modulus of elasticity increased by 11%, and the musical constant by 5%. The static modulus increased by more than 3.5%, but the acoustic parameters calculated on the basis of these results indicated a deterioration of the acoustic properties of completely oven-dried wood. The increase in moisture content to air-dried condition contributed to a slight increase in the mean musical constant at the highest modification temperature.

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Longui, Eduardo Luiz, Cássia Christine Schmidt Gondo, Israel Luiz de Lima, Miguel Luiz Menezes Freitas, Sandra Monteiro Borges Florsheim, Antonio Carlos Scatena Zanatto und José Nivaldo Garcia. „Some Properties of Astronium graveolens Wood Along the Stem“. Floresta e Ambiente 23, Nr. 1 (12.02.2016): 142–49. http://dx.doi.org/10.1590/2179-8087.109714.

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ABSTRACT We investigated the axial variation of specific gravity, shear parallel to the grain and anatomical features of Astronium graveolens wood and related these properties to the anatomy along the stem. We felled five 20-year-old trees and cut discs from four different stem heights, including stem base, 1 meter, 2 meters and 3 meters, for a total of 20 discs, and studied wood samples near the bark and at the base of trunk. Axial variations found appear to provide a balance between mechanical strength of the wood at stem base by the higher density and higher shear by the increase in ray frequency that contributes to locking the vertical cells and growth rings, thus preventing the stem from easily breaking when bent. For hydraulic conductivity, vessels with smaller diameter and frequency at the stem base help prevent the occurrence of embolisms that would reduce water flow along the main stem.

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Salsa, Apriyadi, und Subchan Asy'ari. „ANALISA KELUHAN MUSCULOSKELETAL PADA POSTUR TUBUH PEKERJA PENYERUT KAYU DI MEBEL UD. SETIA USAHA DENGAN MENGGUNAKAN METODE RAPID UPPER LIMB ASSESSMENT“. JKIE (Journal Knowledge Industrial Engineering) 7, Nr. 1 (09.06.2020): 38–45. http://dx.doi.org/10.35891/jkie.v7i1.2100.

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UD.Setia Usaha a business in the field of furniture, during the production process, starting from the activity of the initial raw materials to the process of finished products there is a position that causes interference with the muscular system and needs to improve working posture. Bent position, working with standing, back bent, excessive workload are activities that need to be evaluated gradually. The position of the furniture worker UD. Faithful Business that is not ergonomic. can cause musculoskeletal disorder (MSDs). The purpose of this study was to determine the worker's posture on the activities of furniture workers in the wood shavers at UD. Faithful Business Data collection is done by direct observation to the field and interviews. The data obtained were analyzed using the RULA method, then the grand score was categorized based on the action level of the RULA. The result is the final score of each work posture and level of risk. There are 2 work postures that are often performed by workers. Work posture has a final score of 7 and a higher level of risk is to stand bent and arms outstretched.

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Gu, Jianfeng, Jiangling Wang und Xianfeng Chen. „Bursaphelenchus koreanus sp. n. (Nematoda: Parasitaphelenchidae) in packaging wood from South Korea“. Nematology 15, Nr. 5 (2013): 601–9. http://dx.doi.org/10.1163/15685411-00002705.

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Bursaphelenchus koreanus sp. n., isolated in Ningbo, P.R. China, from packaging wood made from Pinus sp. imported from South Korea, is described. It is characterised by a slim body (a = 28-35), lateral field with four lines, excretory pore located at level of, or slightly posterior to, median bulb, vulva at 75% of total body length, presence of a distinct vulval flap in lateral view, post-uterine branch extending for ca two-thirds of vulva-anus distance, female tail conical and ventrally bent with slightly pointed, irregular or roughened terminus (c′ = 4.1), spicules large and arcuate (27-34 μm) with pointed rostrum, cucullus visible but sometimes reduced to a small blunt extension. The new species belongs to the xylophilus group and is most similar to B. luxuriosae and B. paraluxuriosae. It is distinguished from other Bursaphelenchus species by morphology, ITS-RFLP patterns and sequencing results.

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Wdowiak-Postulak, Agnieszka. „Basalt Fibre Reinforcement of Bent Heterogeneous Glued Laminated Beams“. Materials 14, Nr. 1 (24.12.2020): 51. http://dx.doi.org/10.3390/ma14010051.

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The purpose of this paper is to demonstrate the properties of glued laminated beams made in diverse configurations of timber quality classes, reinforced using a new technique that is cheaper and easy to apply. The aim of the experimental investigations was to enhance reinforcement effectiveness and rigidity of glued laminated beams. The tests consisted of four-point bending of large-scale specimens reinforced with basalt fibres (BFRP). The tests were meant to obtain images of failure, the load–displacement relation and load carrying capacity of basalt fibres depending on the reinforcement ratio. The tests, which concerned low and average quality timber beams, were conducted in a few stages. The aim of the study was to popularize and increase the use of low-quality timber harvested from reafforested areas for structural applications. In the study, theoretical and numerical analysis was carried out for reinforced and unreinforced elements in various configurations of wood quality classes. The aim was to compare the results with the findings of experimental tests. Based on the tests, it was found that the load carrying capacity of beams reinforced with basalt fibre was higher by, respectively, 13% and 20% than that of reference beams, while their rigidity improved by, respectively, 9.99% and 17.13%. The experimental tests confirmed that basalt fibres are an effective structural reinforcement of structural timber with reduced mechanical properties.

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Ennos, A. R., und A. van Casteren. „Transverse stresses and modes of failure in tree branches and other beams“. Proceedings of the Royal Society B: Biological Sciences 277, Nr. 1685 (16.12.2009): 1253–58. http://dx.doi.org/10.1098/rspb.2009.2093.

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The longitudinal stresses in beams subjected to bending also set up transverse stresses within them; they compress the cross section when the beam's curvature is being increased and stretch it when its curvature is being reduced. Analysis shows that transverse stresses rise to a maximum at the neutral axis and increase with both the bending moment applied and the curvature of the beam. These stresses can qualitatively explain the fracture behaviour of tree branches. Curved ‘hazard beams’ that are being straightened split down the middle because of the low transverse tensile strength of wood. By contrast, straight branches of light wood buckle when they are bent because of its low transverse compressive strength. Branches of denser wood break, but the low transverse tensile strength diverts the crack longitudinally when the fracture has only run half-way across the beam, to produce their characteristic ‘greenstick fracture’. The bones of young mammals and uniaxially reinforced composite beams may also be prone to greenstick fracture because of their lower transverse tensile strength.

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Gu, Jianfeng, Jiangling Wang, Helen Braasch, Wolfgang Burgermeister und Thomas Schröder. „Bursaphelenchus paraluxuriosae sp. n. (Nematoda: Parasitaphelenchidae) in packaging wood from Indonesia“. Nematology 14, Nr. 7 (2012): 787–98. http://dx.doi.org/10.1163/156854112x627309.

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Bursaphelenchus paraluxuriosae sp. n., isolated in Ningbo, China, from packaging wood made from Alphitonia sp. (Rhamnaceae) imported from Indonesia is described. It is characterised by a slim body (a = 29-39), lateral field with four lines, excretory pore located at level of median bulb or slightly posterior, vulva at 75% of total body length, presence of a distinct vulval flap in lateral view, post-uterine branch ca two-thirds of the vulva-anus distance, female tail conical and slightly ventrally bent with irregular or roughened terminus (c′ = 4.4), spicules large and arcuate, with pointed rostrum and a cucullus, which is typical for the xylophilus group, but is reduced to a small blunt extension, and three pairs of ventro-sublateral papillae (one pair precloacal, two pairs postcloacal just anterior to the bursal flap and adjacent to each other) and a small single precloacal papilla present. The new species belongs to the xylophilus group and is most similar to B. luxuriosae. It is distinguished from other Bursaphelenchus species by morphology, ITS-RFLP patterns and sequencing results.

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Murata, Koji, und Tsubasa Kanazawa. „Determination of Young's modulus and shear modulus by means of deflection curves for wood beams obtained in static bending tests“. Holzforschung 61, Nr. 5 (01.08.2007): 589–94. http://dx.doi.org/10.1515/hf.2007.082.

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Abstract Young's modulus and shear modulus were simultaneously obtained in a three-point bending test based on Timoshenko's bending theory. Deflection curves of a bent beam were measured by image analysis, and the mechanical properties of the wood were calculated by polynomial regression analysis after excluding the singular region. When beam specimens of spruce (Picea sp.) and mizunara (Quercus crispula) wood were tested, static Young's modulus (E s) and static shear modulus (G s) values could be obtained from the deflection curve using finite element analysis. By comparing the dynamic properties (E d and G d) obtained by a flexural vibration test, it was estimated that E s was greater than E d, while G s was less than G d. However, we suppose that the G s values calculated from the deflection curve are more plausible than those obtained from a conventional bending test.

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Gu, Jianfeng, Munawar Maria, Yiwu Fang, Jie He, Helen Braasch und Hongmei Li. „Bursaphelenchus saudi n. sp. (Tylenchina: Aphelenchoididae) found in packaging wood from Saudi Arabia“. Nematology 18, Nr. 4 (2016): 475–88. http://dx.doi.org/10.1163/15685411-00002971.

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Bursaphelenchus saudi n. sp., isolated in Ningbo, P.R. China, from Pinus packaging wood imported from Saudi Arabia, is described. It is characterised by four lateral lines, excretory pore located between metacorpus and nerve ring (anterior to median bulb before cultured), presence of a thick vulval flap, post-uterine branch ca two-thirds of the vulva-anus distance long, female tail hook-like (slightly ventrally bent before cultured), long and conical, tapering to a bluntly rounded terminus, spicules transversely striated with weakly developed rostrum and condylus, a single precloacal papilla and three pairs of ventro-sublateral papillae (one pair precloacal, two pairs postcloacal just anterior to bursal flap and adjacent to each other). It belongs to the africanus-group of the genus Bursaphelenchus and is most close to B. paraburgeri, B. burgermeisteri and B. obeche. It is distinguished from other Bursaphelenchus species by morphology, ITS-RFLP patterns and partial 18S, ITS and 28S D2-D3 rDNA gene sequencing results.

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Gu, Jianfeng, Jiangling Wang und Jingwu Zheng. „Description of Bursaphelenchus arthuroides sp. n. (Nematoda: Aphelenchoididae), a second parthenogenetic species of Bursaphelenchus Fuchs, 1937“. Nematology 14, Nr. 1 (2012): 51–63. http://dx.doi.org/10.1163/138855411x578365.

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Bursaphelenchus arthuroides sp. n. is described and figured from pine packaging wood originating in Brazil, and inspected in Ningbo harbour, P. R. China. The new species clearly belongs to the fungivorus group. It is characterised by four lines in the lateral field; spicules medium sized (15-17 μm), dorsal part distinctly sclerotised, with a high rounded condylus and a blunted pointed rostrum in the middle position, capitulum with a shallow depression, the posterior third of the dorsal limb ventrally bent, distal end broadly rounded without cucullus; the shape of the female tail conical and slim, posterior third distinctly ventrally bent with a finely pointed terminus; vulval lips slightly protruding but not forming a vulval flap and post-uterine sac extending for about half the vulva-anus distance. Species status is supported by ITS-RFLP patterns and molecular phylogenetic analysis based on partial LSU sequences, ITS1/2 and partial LSU sequences, which revealed that B. arthuroides sp. n. is closest to B. arthuri. Propagation tests also confirmed that the new species is parthenogenetic.

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Ismailiyah Al Athas, Syarifah. „Parametric Design in Timber Gridshell Tectonics“. SHS Web of Conferences 41 (2018): 05004. http://dx.doi.org/10.1051/shsconf/20184105004.

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This paper begins with a simple proposition: rather than mimicking the geometric structures found in nature, perhaps the most effective modes of sustainable fabrication can be found throughunderstanding the nature of materials themselves. The material becomes a design parameter through the constraints of fabrication tools, limitations of material size, and most importantly the productivecapacity of material resistance a given material’s capacity and tendencies to take shape, rather than cutting shape out of material. Gridshell structures provide an intriguing case study to pursue this proposition. Not only is there clear precedent in the form finding experiments of frei Otto and the institute for lightweight structures, but also the very nurbs based tools of current design practices developed from the ability of wood to bend. Taking the bent wood spline quite literally, gridshells provide a means that is at once formally expressive, structurally optimized, materially efficient, and quite simply a delight to experience. The the larger motivation of this work anticipates a parametric system linking the intrinsic material values of the gridshell tectonic with extrinsic criteria such as programmatic needs and environmental response. Through an applied case study of gridshells, the play between form and material is tested out through the author’s own experimentation with gridshells and the pedagogical results of two gridshell studios.The goal of this research is to establish a give and take relationship between top down formal emphasis and a bottom-up material influence.

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Wdowiak-Postulak, Agnieszka, und Janusz Brol. „Ductility of the Tensile Zone in Bent Wooden Beams Strengthened with CFRP Materials“. Materials 13, Nr. 23 (30.11.2020): 5451. http://dx.doi.org/10.3390/ma13235451.

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This article presents experimental results from the bending of technical-scale models of beams reinforced in the tension zone with CFRP (Carbon Fiber Reinforced Polymers) materials, with a focus on the benefits resulting from the increased ductility in the tension zone of these beams. In experimental tests, the mechanical properties of reinforced beams were compared with unreinforced beams in terms of the maximum load, deflection, images of damage, stiffness, and distribution of deformation. The results showed that the proposed reinforcement solution was advantageous due to its strength and stiffness, and the safety of the structure. Based on this analysis, it was concluded that the reinforcement of wood with CFRP materials has a positive effect on the behavior and safety of structures. Also, a method of analytical checking of strengthened beams with small cross-sections was presented in the article.

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Gu, Jianfeng, Jiangling Wang, Helen Braasch, Wolfgang Burgermeister und Jingwu Zheng. „Description of a new subspecies of Bursaphelenchus africanus (Nematoda: Aphelenchoididae) found in packaging wood from Russia“. Nematology 14, Nr. 1 (2012): 27–37. http://dx.doi.org/10.1163/138855411x575593.

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Bursaphelenchus africanus rossicus subsp. n. was detected from Russian packaging wood (Pinus sp.) arriving in China in August, 2009. The spicule shape and size are almost the same as in the B. africanus found in wood from South Africa, but it differs slightly from the South African isolate by longer (mean L=945 vs 691 μm and 1062 vs 766 μm, for males and females, respectively) and slimmer body (a=39.8 vs 35.0 and 40.0 vs 35.1, for males and females, respectively), higher male ratio c (mean c=37.0 vs 28.7) and higher female ratio c′ (mean c′=4.7 vs 3.4), longer female tail (58 vs 42 μm), and also by female tail shape (slightly ventrally bent vs straight). Their ITS-RFLP patterns are also slightly different. Based on the absence of clear morphological differences and relatively small ITS1/2 and D2/D3 LSU sequence divergences, the new isolate is considered as Bursaphelenchus africanus rossicus subsp. n.

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Nechvaloda, Е. Е. „RAFTS AND TRADES RELATED TO WOOD PROCESSING IN RUSSIAN VILLAGES OF STANS 3 AND 4 OF ZLATOUSTOVSKY DISTRICT OF UFA PROVINCE“. History, Archeology and Ethnography of the Caucasus 13, Nr. 4 (15.12.2017): 74–88. http://dx.doi.org/10.32653/ch13474-88.

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The article is based on the data of the field researches carried out by the author in the north-eastern regions of the Republic of Bashkortostan (Duvansky, Mechetlinsky and Belokotaysky Districts) in 2011-2014. In late 19th - early 20th centuries, this territory was part of stans 3 and 4 of the Zlatoustovsky District of the Ufa Province. Most of the Russian population of this area were the “Kunguryaks”, the descendants of immigrants from the northern lands (the former Perm and Vyatka Provinces). The author of the article considers the traditions of wood processing that existed in the Russian villages within the area under study in late 19th - early 20th centuries. Most objects required in the household and in everyday life were made from wood: there were many carved, chiselled, bent objects as well as those braided from rod, birch bark, and bast in the peasant’s house, they were daily used in all spheres of life. Many crafts and trades were connected with wood processing: carpentry, cooperage, joinery, etc. In the villages, there were wood carvers and “painters”, who turned wooden objects into pieces of decorative and applied arts. The traditions of wood processing were brought by the “Kunguryaks” from their historical homeland and they have much in common with the traditions of the Russian North. Among the artistic images of wood carving, there are both ancient amulets - images of ducks, horses, the sun, and Christian symbols - images of a cross, a chalice with grape bunches. In the painting on wood, both the Ural and Vyatka traditions are notable. The article fills in the gaps in the studies of the traditional culture of the Russian ethnos that for now is investigated unevenly in various regions, and the author introduces new material on its material culture into scientific use.

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Mamedov, Sh M., E. G. Shabikova, D. V. Nizhegorodtsev und T. N. Kazakevich. „Method for calculating cross laminated timber panels“. Вестник гражданских инженеров 17, Nr. 5 (2020): 66–71. http://dx.doi.org/10.23968/1999-5571-2020-17-5-66-71.

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Cross-laminated timber (CLT) panels are widely used in the construction of buildings and structures abroad. Regulatory documentation in the Russian Federation does not contain provisions for calculating such structures. The paper considers the method of calculating the floor slab made of CLT panel using the Euler Bernoulli beam theory. General recommendations for the design of cross-glued wood structures are offered, and assumptions of the developed methodology are given. Much attention is paid to the main design characteristics of the bent element. Comparative values of these characteristics from various sources are given. A coefficient is proposed to be used taking into account the features of CLT panels in calculations.

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Gaus, Alvan, und Matthew Rogoyski. „616 PB 296 GROWTH RESPONSES OF VERTICAL APPLE SHOOTS BENT WITH BRANCH BENDER' OR A HAND-TOOL“. HortScience 29, Nr. 5 (Mai 1994): 520d—520. http://dx.doi.org/10.21273/hortsci.29.5.520d.

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The main objective of this research was to compare the growth responses of l-year-old, vertical, apple shoots to bending with a simple hand-tool (HT) or bending with the commercially available Branch Bender® (BB). Single, vigorous, vertical shoots of `Red Chief Delicious (RCD), `Valnur' Jonathan (VJ), and Granny Smith were either bent with the BB or were bent by spirally wrapping the shoot around a 2.5 cm diameter plastic-rod, HT 2 times. Each variety had nine single-tree blocks with a control, BB, and HT as treatments. Measurements were taken on the number of clusters formed, length of subsequent terminal growth, number of shoots and spurs formed, and shoot cross-sectional area. No differences were found in RCD between the BB and the HT on all parameters; however, terminal growth was less with the BB than the control. With VJ, first year shoot cross-sectional area for the BB was less than for the HT. Cluster formation on both 1 and 2-year-old wood was greater with the BB than the control but not with the HT. No differences were found with Granny Smith.

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Лисятников, Mikhail Lisyatnikov, Грибанов, Aleksey Gribanov, Рощина, Svetlana Roshchina, Глебова und Tatyana Glebova. „Calculation and strengthening of maximum stressed near support zones of high glue-wood beam constructions“. Forestry Engineering Journal 5, Nr. 1 (01.05.2015): 187–97. http://dx.doi.org/10.12737/11276.

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We consider the engineering calculation of maximum stressed abutment sections of high glue-wood beam constructions, as well as strengthening these areas with glass nanoassembly. In supports of glued wood beams complex stress arises causing spalling along the fibers, crushing reproach fibers and stretching at an angle to the fibers. The article proposes a new way of strengthening these areas during the production of beams, the essence of which consists in the fact that the ends of the beam constructions are put in clip of glass in one or several layers glued to wood by epoxy resin composition including carbon nanotubes. In the calculations, wood is considered as transport materials described by rheological equations as viscosity elastic elastic body. Physical and mathematical models of fiberglass are selected. Strength of materials formulas calculated geometrical characteristics of the reduced section of strengthened near mounting area of high glued wood beams. Engineering method has shown that the existing method of calculation of wooden bent elements (on the maximum principal stresses in the middle of the span and the maximum shear stress on the support) is not applicable to high glue-wood beams. Tensile stresses at an angle to the fibers in the support areas reach peak values at a load of approximately twice lower than the load at which the maximum shear stress takes place. Engineering calculations found that supports of high beam constructions need to be strengthened. Minimal effect on enhancing by clip of glass nanoassembly by cleaving along the fibers ≥ 8 %, when crumpled across the fibers ≥ 7 %, in tension at an angle to the fibers ≥ 9 %. It was proposed to simplify the formula of geometrical characteristics of the reduced section in order to facilitate further calculations.

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Bakalarz, Michał Marcin, Paweł Grzegorz Kossakowski und Paweł Tworzewski. „Strengthening of Bent LVL Beams with Near-Surface Mounted (NSM) FRP Reinforcement“. Materials 13, Nr. 10 (20.05.2020): 2350. http://dx.doi.org/10.3390/ma13102350.

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The topic of the article is the analysis of the static work of unreinforced and reinforced with composite material timber beams under bending tests. The results of the experimental tests and a brief outline of the characteristics of the internal reinforcement of wood structures are presented. Experimental tests were performed on full-scale beams made of laminated veneer lumber (LVL) with nominal dimensions of 45 × 200 × 3400 mm. Two strips of carbon fiber-reinforced polymer (CFRP) reinforcement were glued into rectangular grooves in the component bottom with two-component epoxy resin (0.62% reinforcement percentage). The reinforcement mainly affected the enhancement of the maximum bending moment values evaluated at the points of application as having concentrated forces of 32% and 24% in comparison to the unreinforced elements. Increases of 11% and 7% in the global modulus of elasticity in the bending and stiffness coefficients were achieved, respectively. The failure of the reference beams was caused by exceeding the tensile strength of the LVL. The reinforced elements were characterized by a greater variation in failure mode, resulting from tension, compression or lateral torsional buckling. The strain profile reading showed a higher utilization of the compression characteristic of veneer in specimens reinforced with carbon laminates.

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Gu, Jianfeng, Jiangling Wang, Weijun Duan, Helen Braasch, Wolfgang Burgermeister und Jingwu Zheng. „Description of Bursaphelenchus paraparvispicularis n. sp. (Nematoda: Aphelenchoididae) found in packaging wood from Hongkong, China“. Nematology 12, Nr. 4 (2010): 557–66. http://dx.doi.org/10.1163/138855409x12584413195455.

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Abstract Bursaphelenchus paraparvispicularis n. sp. is described and figured from pine packaging wood originating in Hongkong, China, and inspected in Ningbo harbour, China. The new species clearly belongs to the hofmanni group. It is characterised by a relatively stout body (a = 26.7 and 26.5 for males and females, respectively), three lines in the lateral field, seven caudal papillae, spicules relatively small (12.6-15.3 μm), mitten-shaped, with lamina dorsal line smoothly arcuate but calomus relatively straight, condylus squared or round, well developed, rostrum well developed with round terminus, cucullus absent, the shape of the female tail, which is short and ventrally bent with a bluntly pointed terminus, and vulval lips not forming a vulval flap. The new species is morphologically closest to B. parvispicularis and can be distinguished by smaller and stouter body, lower female ratio c′ (average 2.8 vs 4.4) and longer spicule condylus. The separate species status is supported by ITS-RFLP patterns and molecular phylogenetic analysis based on ITS1/2 and partial LSU sequences, which revealed that B. paraparvispicularis n. sp. is closest to B. parvispicularis.

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Lauri, Pierre-Éric, und Jean-Marie Lespinasse. „Genotype of Apple Trees Affects Growth and Fruiting Responses to Shoot Bending at Various Times of Year“. Journal of the American Society for Horticultural Science 126, Nr. 2 (März 2001): 169–74. http://dx.doi.org/10.21273/jashs.126.2.169.

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Growing shoots of two apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] genotypes differing in shoot architecture, the preselection X.3318 and the cultivar `Chantecler', were bent on three dates during the summer and one in the winter to evaluate the interactive effects of shoot architecture and bending date on lateral shoot development and growth over 3 years. Bending X.3318, with a high proportion of vegetative lateral shoots on 1-year-old wood, on different dates did not change the percentage of lateral budbreak (62% to 65%). However, bending in June or July increased lateral growth on 1- and 2-year-old wood in a mesotonic position, whereas bending in winter reduced lateral growth and redistributed the shoots more basitonically. Both number and weight of fruits were reduced by bending. In `Chantecler', which forms many flower buds on 1-year-old wood, bending during flower bud formation (June-July) increased the percentage of lateral budbreak (60% vs. 45% for the control) and the number of flower buds. After 3 years of development, early summer treatments reduced the abortion of laterals as compared to the control. As a consequence, bending increased the number, as well as the weight of fruit. These results show that the effects of bending on the development and growth patterns of lateral shoots vary with genotype.

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Brémaud, Iris, Julien Ruelle, Anne Thibaut und Bernard Thibaut. „Changes in viscoelastic vibrational properties between compression and normal wood: roles of microfibril angle and of lignin“. Holzforschung 67, Nr. 1 (01.01.2013): 75–85. http://dx.doi.org/10.1515/hf-2011-0186.

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Abstract This study aims at better understanding the respective influences of specific gravity (γ), microfibril angle (MFA), and cell wall matrix polymers on viscoelastic vibrational properties of wood in the axial direction. The wide variations of properties between normal wood (NW) and compression wood (CW) are in focus. Three young bent trees (Picea abies, Pinus sylvestris and Pinus pinaster), which recovered verticality, were sampled. Several observed differences between NW and CW were highly significant in terms of anatomical, physical (γ, shrinkage, CIELab colorimetry), mechanical (compressive strength), and vibrational properties. The specific dynamic modulus of elasticity (E′/γ) decreases with increasing MFA, and Young’s modulus (E′) can be satisfactorily explained by γ and MFA. Apparently, the type of the cell wall polymer matrix is not influential in this regard. The damping coefficient (tanδ) does not depend solely on the MFA of NW and CW. The tanδ – E′/γ relationship evidences that, at equivalent E′/γ, the tanδ of CW is approximately 34% lower than that of NW. This observation is ascribed to the more condensed nature of CW lignins, and this is discussed in the context of previous findings in other hygrothermal and time/frequency domains. It is proposed that the lignin structure and the amount and type of extractives, which are both different in various species, are partly responsible for taxonomy-related damping characteristics.

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Webb, Sara L. „Windstorm damage and microsite colonization in two Minnesota forests“. Canadian Journal of Forest Research 18, Nr. 9 (01.09.1988): 1186–95. http://dx.doi.org/10.1139/x88-182.

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Scattered trees were uprooted, snapped, or bent during a 1983 windstorm in two northwestern Minnesota pine forests. I tested potential correlates (tree species, tree size, cause of damage) of damage type, and compared consequences of the uprooting, snapping, and bending of trees by assessing postdamage survival and by surveying formation and colonization of microsites (mounds, pits, stumps, and dead boles). Larger trees damaged directly by wind were usually snapped and killed in both study areas, regardless of tree species. Smaller trees damaged by falling neighbors were either (i) bent without sustaining mortality or forming microsites, a damage type prevalent among strong-wooded Acersaccharum and Ostryavirginiana in a Pinus–Acer study area, or (ii) uprooted, forming small mounds and pits, a damage type prevalent among weakwooded Abiesbalsamea and Picea spp. in a Pinus–Abies study area. Bent trees usually survived, at least for several years. However, uprooted and snapped trees were equally unlikely to survive their damage. Thus, uprooting and snapping were equally likely to result in dead bole formation. Windstorm-related microsites covered small proportions (6 and 18%) of the floor of the two forests, most as dead boles rather than as stumps, mounds, or pits. Microsites from uprooting, microsites from snapping, and background substrates did not differ in colonizing tree flora but did differ in density of colonists. The role of microsites varied with the autecology of tree species present. In the Pinus–Abies area, rotting wood of stumps and boles was the major establishment substrate for all regenerating tree species. In the Pinus–Acer area, Acersaccharum and A. rubrum were numerically dominant over other species on all substrates, with seedling densities highest away from microsites. Observed patterns of survival and tree regeneration indicate that uprooting and snapping of trees do not differ strongly in their consequences for either forest.

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Dahoua, Lamri, und Fakhridine Boymatov. „Endurance of the wooden bridge reinforced by the dowel plates“. Studia Geotechnica et Mechanica 40, Nr. 3 (20.10.2018): 202–7. http://dx.doi.org/10.2478/sgem-2018-0023.

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Abstract The most important piece of road infrastructure is bridges. Wooden bridges have advanced constantly during the past decades. The trend began in Scandinavian countries but has also now gained significant ground in Russia. This research studies experimental endurance potential of the joints of the wooden beam while considering the coefficient of asymmetry of the cycle, which corresponds to the actual operating conditions. Performance analysis of the composite bars is carried out based on the experiment; the development of a special methodology for calculating the joints of wooden elements with the dowel plates for their better endurance is also introduced in this paper. The results of experimental studies on the performance of bending composite wooden bridge bars based on dowel plates operating under cyclic influences thus determine the endurance limit of wood for composite wooden bridge beams based on dowel plates. The calculation technique and interdependence of the endurance coefficient affecting the asymmetry coefficient of the bent composite wooden bridge bars on the dowel plates under cyclic loading are considered. The experimental data on the endurance of composite wooden bridge beams have been obtained, and separate analysis has been made of the compounds under cyclic loading performance; a method has been developed for calculating the bent composite wooden bridge bars reinforced by the dowel plates under cyclic influences.

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Allona, Isabel, Michelle Quinn, Elizabeth Shoop, Kristi Swope, Sheila St Cyr, John Carlis, John Riedl et al. „Analysis of xylem formation in pine by cDNA sequencing“. Proceedings of the National Academy of Sciences 95, Nr. 16 (04.08.1998): 9693–98. http://dx.doi.org/10.1073/pnas.95.16.9693.

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Secondary xylem (wood) formation is likely to involve some genes expressed rarely or not at all in herbaceous plants. Moreover, environmental and developmental stimuli influence secondary xylem differentiation, producing morphological and chemical changes in wood. To increase our understanding of xylem formation, and to provide material for comparative analysis of gymnosperm and angiosperm sequences, ESTs were obtained from immature xylem of loblolly pine (Pinus taeda L.). A total of 1,097 single-pass sequences were obtained from 5′ ends of cDNAs made from gravistimulated tissue from bent trees. Cluster analysis detected 107 groups of similar sequences, ranging in size from 2 to 20 sequences. A total of 361 sequences fell into these groups, whereas 736 sequences were unique. About 55% of the pine EST sequences show similarity to previously described sequences in public databases. About 10% of the recognized genes encode factors involved in cell wall formation. Sequences similar to cell wall proteins, most known lignin biosynthetic enzymes, and several enzymes of carbohydrate metabolism were found. A number of putative regulatory proteins also are represented. Expression patterns of several of these genes were studied in various tissues and organs of pine. Sequencing novel genes expressed during xylem formation will provide a powerful means of identifying mechanisms controlling this important differentiation pathway.

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MITRA, SANTANU, THINGBAIJIAM MONICA und MEMA DEVI WAIKHOM. „A new species of freshwater crab of the genus Badistemon Yeo & Ng, 2007 (Decapoda: Brachyura: Potamidae: Potamiscinae) from Manipur State, India, with the reassignment of Potamiscus pealianus (Wood-mason, 1871)“. Zootaxa 4838, Nr. 4 (28.08.2020): 475–90. http://dx.doi.org/10.11646/zootaxa.4838.4.2.

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A new species of potamid crab of the genus Badistemon Yeo & Ng, 2007, is described from Kamjong district of Manipur, India. Badistemon fulvum n. sp., can be distinguished from congeners by a distinct combination of carapace and gonopod characters: carapace subquadrate, convex, dorsal surface glabrous, cervical groove superficial, anterolateral margin longer than posterolateral margin; cornea relatively large; sixth male pleonal somite trapezoidal in shape, male telson broader than long; terminal segment of male first gonopod relatively long, outwardly bent, sub cylindrical with low and short dorsal flap, tip pointed, groove for male second gonopod terminal. Holotype and paratypes of Potamiscus pealianus (Wood-mason, 1871) are re-examined, and the species is here referred to Badistemon as carapace morphology and male gonopods characters are found congeneric with the genus. A key for all the three species of Badistemon are provided.

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Guzmán, Nancy, Roger Moya und Olmán Murillo. „Evaluation of Bent Trees in Juvenile Teak (Tectona grandis L.f.) Plantations in Costa Rica: Effects on Tree Morphology and Wood Properties“. Forests 8, Nr. 3 (14.03.2017): 79. http://dx.doi.org/10.3390/f8030079.

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Lipovšek, Matej, Tadeja Brinovec und Marina Brinovec. „Epipactis helleborine (L.) Crantz subsp. moratoria A. Riechelmann & A. Zirnsack., a new subspecies of Broad-leaved Helleborine in Slovenia“. Hacquetia 16, Nr. 1 (01.06.2017): 13–18. http://dx.doi.org/10.1515/hacq-2016-0011.

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Abstract The group of Epipactis helleborine s.l. includes several subspecies. A new subspecies Epipactis helleborine subsp. moratoria was determined in Slovenia in 2015. It thrives in mixed wood in a region of Gorica at Raztez. Morphologic and phenomenological comparison confirmed clear differences between E. helleborine subsp. moratoria and E. helleborine subsp. helleborine. The characteristic differences seen in E. helleborine subsp. moratoria are the stem which is more or less bent at the level of the leaf base, the plants are smaller and more slender than E. helleborine, there are also differences in the flowers and the leaves. The ovary in E. moratoria is often in a horizontal position, especially at the time of fruiting, wheras in E. helleborine ovary usually hangs down. All of the wild orchids in Slovenia are protected species and among them it is Epipactis helleborine subsp. moratoria which, up till now is only known at one site.

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JOHNSON, CHELSÉA B., EVAN QUAH S. H., SHAHRUL ANUAR, M. A. MUIN, PERRY L. WOOD, JR., JESSE L. GRISMER, LEE F. GREER et al. „Phylogeography, geographic variation, and taxonomy of the Bent-toed Gecko Cyrtodactylus quadrivirgatus Taylor, 1962 from Peninsular Malaysia with the description of a new swamp dwelling species“. Zootaxa 3406, Nr. 1 (01.08.2012): 39. http://dx.doi.org/10.11646/zootaxa.3406.1.3.

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A review of the taxonomic status of the Bent-toed Gecko Cyrtodactylus quadrivirgatus Taylor, 1962 based on a molecularphylogeny, scalation, and color pattern analyses indicate that it is composed of a single, recently expanding, widespreadpopulation with weakly supported phylogeographic substructuring with no discrete morphological differentiation betweenpopulations. However, based on sampling, significant mean differences in selected scale counts occur between some pop-ulations. The molecular phylogeny and morphological analysis strongly indicate lineage independence between a subsetof individuals from the Bukit Panchor, Penang population and their closest relative C. pantiensis Grismer, Chan, Grismer,Wood & Belabut, 2008 from southern Peninsular Malaysia. Furthermore, the analyses indicate that the individuals of thissubset are conspecific and not part of C. quadrivirgatus as previously suggested. Additionally, this subset is morphologi-cally distinct from all other Sundaland species of Cyrtodactylus, and as such is described herein as Cyrtodactylus payacola sp. nov.

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Fang, Yiwu, Hongmei Li, Munawar Maria und Wim Bert. „Description of Pseudaphelenchus zhoushanensis n. sp. (Tylenchina: Aphelenchoididae) found in the wood of Pinus thunbergii at Zhoushan Islands, Zhejiang Province, China“. Nematology 18, Nr. 10 (2016): 1151–64. http://dx.doi.org/10.1163/15685411-00003021.

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Pseudaphelenchus zhoushanensis n. sp. was isolated from a dead Pinus thunbergii at Changgang Mountain, Zhoushan Islands, Zhejiang Province, China. It is characterised by the small to medium length body, cuticle slightly annulated, presence of three lateral lines, stylet 9.0-10.7 μm with small but conspicuous basal knobs, excretory pore located from same level as the metacorpus to slightly anterior to metacorpus, true bursa surrounding entire tail but inconspicuous, male tail conical with a single mucron, spicule with distinct condylus and rostrum strongly arcuate to a pointed end, female tail conical with annulation, strongly ventrally bent in distal part of tail, with terminus bluntly pointed or finely mucronate. Phylogenetic analyses using sequences of the18S and 28S D2-D3 regions of rDNA confirmed the status of P. zhoushanensis n. sp. as a new species. Combining the molecular phylogenetic analyses, morphology and biology of P. zhoushanensis n. sp. and Tylaphelenchus jiaae indicates that T. jiaae is a member of Pseudaphelenchus to which it is herein transferred as P. jiaae n. comb. (= T. jiaae).

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Labudin, Boris V., Egor V. Popov, Ekaterina S. Oshchepkova, Valery V. Sopilov, Anastasia V. Ruslanova und Alexandr A. Fukalov. „Influence of cover splices on the stress-strain state of plate-ribbed wood-composite panels“. Structural Mechanics of Engineering Constructions and Buildings 16, Nr. 6 (15.12.2020): 439–51. http://dx.doi.org/10.22363/1815-5235-2020-16-6-439-451.

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Wooden-composite plate-ribbed bent panels with structural plywood and oriented strand board sheathing with breaks are considered. An overview of studies researching and improving the effectiveness of different types of panels is presented. On the basis of the theory of calculation of composite rods by A.R. Rzha- nitsyn, a mathematical model has been compiled, which makes it possible to calculate the stress-strain state of these structures, taking into account the pre- sence of breaks in the sheathing and the flexibility of the mechanical fasteners of the sheathing and ribs. An equation for finding the coordinates of the most dangerous section of wooden ribs in the presence of breaks in the sheathing, which may not match with the middle of the span, is obtained. Panels with sheathing in a compressed zone with different locations of joints, symmetrically relative to the middle of the panel span are considered. Panels without joints in the skin are considered to compare the results. The graphs of the dependence of the maximum tensile stresses in the ribs in the most dangerous section and the maximum vertical displacements from the stiffness coefficient of the shear ties and the location of the breaks in the sheathing are presented. The values of the coefficients for the engineering design of panels, taking into account the decrease in the strength and deformation characteristics of the composite section of panels with breaks in the sheathing, as compared to panels with a solid sheathing, are obtained. The conclusions and recommendations, based on the results of the investigations, which can be used in the design of wooden-composite plate-ribbed structures, are formulated.

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