Статті в журналах з теми "Bark resin"
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1
Kain, Günther, Eugenia Mariana Tudor, and Marius-Catalin Barbu. "Bark Thermal Insulation Panels: An Explorative Study on the Effects of Bark Species." Polymers 12, no. 9 (September 19, 2020): 2140. http://dx.doi.org/10.3390/polym12092140.
Повний текст джерелаАнотація:
Tree bark is a byproduct of the timber industry which accrues in large amounts, because approximately 10% of the volume a log is bark. Bark is used primarily for low-value applications such as fuel or as a soil covering material in agriculture. Within the present study, thermal insulation panels made from larch, pine, spruce, fir and oak tree bark with different resins (urea formaldehyde, melamine formaldehyde, Quebracho, Mimosa) as a binder are discussed. Also, the properties of panels made from larch bark mixed with industrial popcorn are investigated. The physical-mechanical properties of the panels, which are dependent on panel density, bark species, resin type, resin content and particle size, are analyzed. The bark species has a minor effect on the mechanical characteristics of the panels, while the compression ratio is important for the panel strength, and hence, barks with lower bulk density are preferable. Under laboratory conditions, panels made with green tannin resins proved to have adequate properties for practical use. The addition of popcorn is a means to lower the panel density, but the water absorption of such panels is comparably high. The bark type has a minor effect on the thermal conductivity of the panels; rather, this parameter is predominantly affected by the panel density.
2
Wang, Changshui, and Tingzhi Liu. "Activated carbon materials derived from liquefied bark-phenol formaldehyde resins for high performance supercapacitors." RSC Advances 6, no. 107 (2016): 105540–49. http://dx.doi.org/10.1039/c6ra20373f.
Повний текст джерелаАнотація:
Bark phenolic compounds have been used to partially substitute petroleum-based phenol in a resin synthesis due to their similarity. Activated carbons derived from the liquefied bark-phenol formaldehyde resins exhibit excellent capacitance.
3
Amen-Chen, C., B. Riedl, X. M. Wang, and C. Roy. "Softwood Bark Pyrolysis Oil-PF Resols. Part 3. Use of Propylene Carbonate as Resin Cure Accelerator." Holzforschung 56, no. 3 (April 29, 2002): 281–88. http://dx.doi.org/10.1515/hf.2002.046.
Повний текст джерелаАнотація:
Summary Phenol-formaldehyde (PF) resols were prepared with different proportions of phenol replaced with softwood bark pyrolysis oils under varying formaldehyde to phenolics molar ratios and sodium hydroxide contents. Propylene carbonate (PC) was added to these adhesives to improve the cure of resins. The cure behavior was characterized by differential scanning calorimetry (DSC). Cure kinetics and amount of cure of the experimental resin were improved by adding PC to the resins. Low amounts of PC were used (less than 1.5% of PC on a resin solid basis) to avoid premature gelling of the adhesives. Results obtained by DSC suggested that PC catalyzed the resin cure reaction and also participated in resin cross-linking reactions. Low percentages of PC, 0.5 and 1% on a resin solid basis, were added to the experimental resins for bonding strandboards. These addition levels did not significantly improve mechanical properties of strandboards. It is concluded that a PC addition level of more than 1% by wt (on a resin solid basis) should be used to modify the mechanical properties of panels bonded with pyrolysis oil-PF resins.
4
Mirski, Radosław, Jakub Kawalerczyk, Dorota Dziurka, Joanna Siuda, and Marek Wieruszewski. "The Application of Oak Bark Powder as a Filler for Melamine-Urea-Formaldehyde Adhesive in Plywood Manufacturing." Forests 11, no. 12 (November 25, 2020): 1249. http://dx.doi.org/10.3390/f11121249.
Повний текст джерелаАнотація:
The woodworking industry generates a great amount of bark which has not yet found a wider industrial application. None of the previously conducted research has considered oak bark application (which is one of the most often processed wood species in Poland) as a filler for wood adhesives. Moreover, no studies have determined the properties of bark containing melamine-urea-formaldehyde resin (MUF), which increasingly replaces pure urea-formaldehyde adhesives. Thus, the aim of the study was to determine the possibility of grinded oak bark application as a filler for MUF adhesive in plywood manufacturing. The chemical composition of oak bark was evaluated. Properties of liquid resins, such as viscosity, gel time, pH, and solid content, were determined. Chemical interaction between the filler and resin was assessed with using Fourier-transform infrared (FTIR) spectroscopy. Plywood panels manufactured using MUF adhesive filled with different bark concentrations (10%, 15%, 20%, 25%) were tested in terms of such properties as formaldehyde release and bonding quality. Studies have shown an improvement in liquid resin properties. The course of FTIR spectra did not explain the chemical interaction between the polymer and the filler. The addition of oak bark at a concentration of 15% made it possible to produce plywood panels characterized by reduced formaldehyde release and improved bonding quality.
5
Alfaro, René I., Fangliang He, Elizabeth Tomlin, and G. Kiss. "White spruce resistance to white pine weevil related to bark resin canal density." Canadian Journal of Botany 75, no. 4 (April 1, 1997): 568–73. http://dx.doi.org/10.1139/b97-063.
Повний текст джерелаАнотація:
Examination of the bark from the uppermost lateral branches of white spruce, Picea glauca (Moench) Voss, indicated that trees resistant to attack by the white pine weevil, Pissodes strobi Peck, had significantly higher number and density of vertical resin canals per unit of bark area (mm2) than susceptible trees. The number and density of resin canals were also positively correlated with tree growth rate, an indicator of tree vigor. The density of the resin canals found near the periphery of the bark (outer resin canals) had higher correlation with resistance and growth than inner resin canals. Measurements of resin canals on the bark of lateral branches correlated well with measurements on the bark of the leader of the same tree, indicating that lateral samples could be used to screen white spruce for resistance to weevils. Key words: Picea glauca, Pissodes strobi, pest management, tree genetics.
6
Denham, Sander O., David R. Coyle, A. Christopher Oishi, Bronson P. Bullock, Kari Heliövaara, and Kimberly A. Novick. "Tree resin flow dynamics during an experimentally induced attack by Ips avulsus, I. calligraphus, and I. grandicollis." Canadian Journal of Forest Research 49, no. 1 (January 2019): 53–63. http://dx.doi.org/10.1139/cjfr-2018-0024.
Повний текст джерелаАнотація:
The success of tree colonization by bark beetles depends on their ability to overcome host tree defenses, including resin exudation and toxic chemicals, which deter bark beetle colonization. Resin defenses during insect outbreaks are challenging to study in situ, as outbreaks are stochastic events that progress quickly and thus preclude the establishment of baseline observations of non-infested controls. We use synthetic aggregation pheromones to demonstrate that confined Ips bark beetle herbivory can be successfully initiated to provide opportunities for studying interactions between bark beetles and their hosts, including the dynamics of constitutive and induced resin exudation. In Pinus taeda L. plantations between 12 and 19 years old in North and South Carolina, U.S., trees were affixed with pheromone lures, monitored for evidence of bark beetle attacks, and resin samples were collected throughout the growing season. Baiting increased beetle herbivory to an extent sufficient to produce an induced resin response. Attacked trees exuded about three times more resin at some time than control trees. This supports previous work that demonstrated that information on constitutive resin dynamics alone provides an incomplete view of a host tree’s resistance to bark beetle attack.
7
Sommerlatte, Hilary, and Ben-Erik Van Wyk. "Observations on the Association between Some Buprestid and Cerambycid Beetles and Black Frankincense Resin Inducement." Diversity 14, no. 1 (January 16, 2022): 58. http://dx.doi.org/10.3390/d14010058.
Повний текст джерелаАнотація:
Samburu resin harvesters in northern Kenya maintain that frankincense resin flow from Boswellia neglecta and Commiphora confusa is induced by insect larval activity. Observations on the insects’ larval behaviour support these claims. During the frankincense harvest, buprestid beetle larvae, identified as a Sphenoptera species, are found under B. neglecta resin, eating the monoterpene-rich inner bark, which apparently stimulates the trees to produce copious amounts of fresh resin. The same behaviour was observed with cerambycid beetle larvae, identified as Neoplocaederus benningseni Kolbe, on C. confusa trees. Remarkably, these insects have developed the capacity to digest the resin-saturated inner bark and overcome the toxic, repellent characteristics of oleo-monoterpenes. The frankincense resin also appears to act as a protective covering during the insects’ larval and pupal stages. Excessive tree damage was not noted from these insect invasions. Even though the tree species are from different genera, the resin produced by both is black, with a very similar aromatic chemical profile. The question thus arises as to whether the larval feeding behaviour of these beetle species has an influence, not only on the physical appearance but also on the chemical composition of the resins.
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Field, J. A., M. J. H. Leyendeckers, R. Sierra Alvarez, G. Lettinga, and L. H. A. Habets. "The Methanogenic Toxicity of Bark Tannins and the Anaerobic Biodegradability of Water Soluble Bark Matter." Water Science and Technology 20, no. 1 (January 1, 1988): 219–40. http://dx.doi.org/10.2166/wst.1988.0026.
Повний текст джерелаАнотація:
The principal methanogenic toxins of bark soluble matter were identified as the tannins. The tannins, which were measured with a selective tannin adsorbant called polyvinylpyrrolidone, accounted for about half of the aqueous extractable COD of tree bark. The 50% inhibitory concentration of bark tannins averaged approximately 600 mg COD L−1 (350 mg tannin solids L−1). The toxicity caused by the resin fraction of bark was demonstrated not to be very important to the methanogenic toxicity of aqueous extracts. While tree resin compounds were found to be very toxic to methanogenic bacteria, the solubility of the resin fraction was very poor due to the low natural pH during the aqueous extraction. Additionally, those compounds aqueous extracted from tree resin at the natural pH were not as toxic as all the tree resin compounds solubilized by alkali and supplied at similar concentrations. Anaerobic biodegradability results indicated that 30 to 50% of the bark water soluble COD can be acidified to methanogenic substrates during short term digestion. Pine and birch bark water soluble COD acidified up to 70% after long term batch digestion of 7 weeks. The high level of bark aqueous extract UV absorbance elimination by anaerobic digestion and the appearance of intermediates indicated that at least some of the bark phenolic compounds were included in the methanogenic substrate.
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Derkyi, N. S. A. "Effect of Extraction Solvent on Tannin-Formaldehyde Adhesives for Plywood Production." Journal of Energy and Natural Resource Management 1, no. 2 (February 21, 2018): 120–26. http://dx.doi.org/10.26796/jenrm.v1i0.27.
Повний текст джерелаАнотація:
Pine bark is a good source of natural polyphenolic compounds for wood adhesives. The objective of this study was to obtainthe most suitable solvent for extracting pine tannins in the preparation of tannin-formaldehyde plywood adhesives. Aqueousacetone, aqueous ethanol, aqueous NaOH and water as solvents were used to obtain crude tannins from pine bark. Thetannin content, sugar content and Stiasny number of the extracts were determined. Using the extracts from the solventextractions, synthesis of tannin-formaldehyde resin was carried out. Plywood panels were made using the synthesized resinsand the quality of the resins in plywood application determined. The quality of tannin-formaldehyde resins produced from thetannins were generally in close agreement with the chemical characteristics of the extracts obtained from the various solventextractions. The aqueous NaOH extraction although gave very high tannin yield (16.1%), its associated high sugar content(33.8%) and very low Stiasny number (49) resulted in poor quality resin. Similarly, although aqueous extraction gave a veryhigh Stiasny number (91), its low tannin yield (8.7%) might not be of commercial interest. The extraction process that gave ahigh tannin yield (12.9%) and a very good Stiasny number (81.5) with a corresponding good quality resin (shear strength =1.9 MPa, 22% delamination) was found for 60% aqueous ethanol extraction.
10
Yuniar, Annisa Fitri, I. Wayan Arya Krishnawan Firdaus, and Rahmad Arifin. "THE EFFECT OF ULIN (Eusideroxylon zwageri) STEM BARK EXTRACT ON THE GROWTH OF Candida albicans ON ACRYLIC RESIN DENTURE PLATES." Dentino : Jurnal Kedokteran Gigi 6, no. 1 (May 11, 2021): 31. http://dx.doi.org/10.20527/dentino.v6i1.10637.
Повний текст джерелаАнотація:
ABSTRACTBackground: Candida albicans is the main microorganism that causes denture stomatitis, thus denture soaking in cleansing solution is needed to protect them from Candida albicans contamination. The 0.2% Chlorhexidine gluconate is one of denture cleansers that induce side effects at prolonged use. An alternative ingredient that can be used as a denture cleanser is ulin stem bark extract. Objective: To determine the effect of ulin stem bark extract at 20%, 40%, 60%, 80%, 100% concentration on the growth of Candida albicans on acrylic resin denture plates. Method: True Experimental with post-test only with control group design was employed under 7 treatment groups consisting ulin stem bark extract at 20%, 40%, 60%, 80%, 100% concentration, 0.2% Chlorhexidine gluconate, and aquadest in a total of 28 samples. Acrylic resin samples that had been exposed to Candida albicans weresoaked in respective treatment for 15 minutes. Results: The average of Candida albicans colonies on acrylic resin denture plates after soaking in ulin bark extract at 20%, 40%, 60%, 80%, 100% concentration, 0.2% Chlorhexidine gluconate, and aquadest were 29.5 CFU/ml, 13.0 CFU/ml, 0 CFU/ml, 0 CFU/ml, 0 CFU/ml, 0 CFU/ml, and 155 CFU/ml. Based on Mann Whitney test, there was no significant difference when ulin stem bark extract at 60% concentration was compared to 0.2% Chlorhexidine gluoconate. Conclusion: Ulin stem bark extract at 20%, 40%, 60%, 80%, and 100% concentration have been proven to reduce Candida albicans colonies on acrylic resin denture plates, and the 60% concentration is equivalent to 0.2% Chlorhexidine gluconate.Keywords: Candida albicans,Eusideroxylon zwageri, Heat cured acrylic resin. Ulin stem bark extract.
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Wicaksono, Teddy Wicaksono, Akhmad Farid, Nova Risdiyanto Ismail, and Arief Rizki Fadhillah. "PENGARUH DEBIT ALIRAN RESIN BISPHENOL A LP-1Q-EX PADA METODE VACUUM INFUSION RESIN TERHADAP KEKUATAN TARIK KOMPOSIT SERAT KULIT POHON WARU (HIBISCUS TILIACEUS)." Jurnal Energi dan Teknologi Manufaktur (JETM) 4, no. 01 (June 30, 2021): 17–24. http://dx.doi.org/10.33795/jetm.v4i01.71.
Повний текст джерелаАнотація:
Research on natural fiber composites is being carried out in various parts of the world to produce solutions to environmental problems by utilizing natural fiber materials prepared for environmentally friendly and renewable materials. The natural fiber currently being developed for composite reinforcement is hibiscus bark fiber. This study aims to determine the effect of the flow rate of bisphenol A resin LP-1Q-EX on the vacuum infusion resin method on the tensile strength of hibiscus bark fiber composites. The method used in this study is the fiber structure model in the direction of tensile load, composite using hibiscus bark fiber (Hibiscus tiliaceus), composite using bisphenol A resin LP-1Q-EX, composite using mass fraction with a ratio of 60 fibers: 40 resin, Waru tree bark was treated with 6% NaOH alkaline soaking (aquades 938.8 grams, and NaOH 61.2 grams) for 120 minutes, the number of hibiscus tiliaceus bark fibers in one composite material was 22 fibers with a material thickness of 3.2 mm (according to ASTM D638-03 Type 1 standard), the composite was produced using the vacuum infusion resin method with variations in resin flow rate of 1.19 ml/s, 3.66 ml/s, 4.67 ml/s. The testing process in this study is a composite tensile test using the ASTM D638-03 Type I standard. The analysis of the fractures that occur in each specimen uses macro photos, namely the process of taking several photos of the fracture after the specimen is subjected to a tensile test using a digital camera placed on the ground. topped a tripod. The results of the composite tensile test showed that the variation of resin flow rate of 1.19 ml/s had the lowest tensile strength of 282.94 MPa, while the variation of flow discharge of 3.66 ml/s had the highest tensile strength of 301.75 MPa. and the flow variation of 4.67 ml/s has a tensile strength of 284.54 MPa. Based on the results of the tensile test of the hibiscus tiliaceus bark fiber composite using the vacuum infusion resin method, the highest strength was obtained at a variation of the resin flow rate of 3.66 ml/s.
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Harsini, H. "Pengaruh Ekstrak Etanolik Kulit Batang Jambu Mete (Anacardium occidentale Linn) sebagai Bahan Kumur terhadap Daya Perlekatan C. Albicans pada Plat Resin Akrilik." Majalah Kedokteran Gigi Indonesia 19, no. 1 (October 20, 2016): 137. http://dx.doi.org/10.22146/majkedgiind.15398.
Повний текст джерелаАнотація:
Latar Belakang: Candia albicans adalah mikroorganisme yang berkoloni melekat pada permukaan gigi maupun gigi tiruan. Obat kumur mengandung bahan tarapeutik yang berfungsi sebagai antibakteri. Kulit batang jambu mete antara lain mengandung senyawa fenolik yang dapat berkhasiat sebagai antibakteri. Tujuan penelitian: Untuk mengetahui apakah ekstrak etanolik kulit batang jambu mete sebagai bahan kumur berpengaruh terhadap gaya perlekatan C. Albicans pada plat resin akrilik. Metode penelitian: Ekstrak kulit batang jambu mete diperoleh dengan menggunakan metode maserasi dan menggunakan etanol sebagai pelarut. Bahan kumur ekstrak kulit batang jambu mete dibuat dengan komposisi bahan kumur standar dengan menambahkan ekstrak etanolik kulit batang jambu mete dengan konsentrasi 1%, 2%, 3%, 4%, dan 5% sebagai agen antibakteri. Penelitian dilakukan dengan menggunakan plat resin akrilik yang dibuat bentuk disk dengan ukuran diameter 10 mm dan tebal 2 mm sebanyak 24 buah, yang dibagi dalam 6 kelompok yaitu 5 kelompok perlakuan dengan menggunakan bahan kumur yang mengandung ekstrak kulit batang jambu mete dan 1 kelompok kontrol menggunakan bahan kumur standar. Seluruh plat resin dimasukkan dalam tabung C. Albicans 10 CFU/ml selama 5 menit, kemudian plat diambil dan dimasukkan dalam larutan bahan kumur standar sebagai kontrol dan larutan bahan kumur yang mengandung ekstrak kulit batang jambu mete untuk kelompok perlakuan selama 3 menit dan digetarkan. Cairan kemudian diambil sebanyak 0,1 ml dan ditanam pada piring petri dengan agar saboruraud dan diinkubasi selama 48 jam. Perhitungan koloni dilakukan menggunakan counter. Hasil penelitian: Hasil daya perlekatan pada bahan kumur standar 1912,50±14,93; pada bahan kumur dengan ekstrak 1% = 1757,50±20,16; 2% = 1335±17,08; 3% = 1220; 4% = 915±22,17 dan 5% = 670,00±38,37. Analisis varian satu jalur memperlihatkan pengaruh yang bermakna ekstrak etanolik kulit batang jambu mete terhadap daya lekat C. Albicans pada plat resin akrilik (p<0,05). Hasil LSD menunjukkan bahwa terdapat perbedaan yang bermakna antar seluruh kelompok perlakuan (p<0,05). Kesimpulan: Ekstrak etanolik kulit batang jambu mete sebagai bahan kumur berpengaruh terhadap daya perlekatan C. Albicans pada plat resin aklirik. Background: C. Albicans is a microorganism which colonized on the tooth or denture prosthesis surfaces. Mouthwashes usually contain therapeutic agent as antibacterial. The bark of Annacardium occidentale contains fenolic as antibacterial activity. The aim of this research was to determine the influence of the etanolic ectract of anacardium occidentale bark as mouthwashes on C. Albicans adherence. Method: the extract of anacardium occidentale bark was conducted in maceration method and used ethanol as solvent. Mouthwashes were made in standart composition and added annacardium occidentale bark extract 1%, 2%, 3%, 4% and 5% as antibacterial agent. As a negative control was used standart mouthwashes without extract. The research used 24 resin acrylic which made in disk shape with diameter 10 mm. This acrylic were divided in 6 group, there were 5 group treated with mouthwash that contain extract anacardium occidentale bark and 1 group treated with standart mouthwashes. All of resins plate were incubated in C. Albicans solution for 5 minute. After that resin acrylic plate were immersed in standart mouthwashes as a control and mouthwashes with anaracium occidentale bark extract and vibrate for 3 minutes. The solution then taken 0,1 ml and planted in petry dish with saboruraud agar and incubated for 48 hours. Result: Attachment of candida alvicans was: 1912,50±14,93 as control and mouthwash with extract were 1% = 1757,50±20,16; 2% = 1335±17,08; 3% = 1220; 4% = 915±22,17 and 5% = 670,00±38,37. Analyzed with one way Anova showed that the extract of annaracium occidentale bark as mouthwash influenced the cancida albicans adherence on resin acrylic surface (p<0,05). LSD analyzed showed there were significant differenced between all groups (p<0,05). Conclusion: The extract of anacardium occidentale bark extract as mouthwash were influence of the C. Albicans adherence on resin acrylic surface.
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Yongram, Chawalit, Bunleu Sungthong, Ploenthip Puthongking, and Natthida Weerapreeyakul. "Chemical Composition, Antioxidant and Cytotoxicity Activities of Leaves, Bark, Twigs and Oleo-Resin of Dipterocarpus alatus." Molecules 24, no. 17 (August 25, 2019): 3083. http://dx.doi.org/10.3390/molecules24173083.
Повний текст джерелаАнотація:
Dipterocarpus alatus (Dipterocarpaceae) is a medicinal plant whose use is well known for the treatment of genito-urinary diseases. However, there is no report of its cytotoxic potential. In this study, the chemical composition, antioxidant and cytotoxic activities of extracts of the leaves, bark, twigs and oleo-resin from D. alatus are investigated. Cytotoxicity was measured by the neutral red (NR) assay against HCT116, SKLU1, SK-MEL2, SiHa and U937 cancer cell lines and antioxidant capacity was evaluated by DPPH, ABTS radical scavenging, and ferric reducing antioxidant power (FRAP) assays. The chemical composition was analyzed by gas chromatography–mass spectrometry (GC-MS). Leaf, bark and twig extracts exhibited stronger antioxidant activity than oleo-resin, with bark extract showing the highest antioxidant activity and the highest total phenolic content. All samples showed more cytotoxic activity against the U937 cell line than HCT116, SKLU1, SK-MEL2 and SiHa cells with oleo-resin being more cytotoxic than melphalan against U937 cells. Chemical composition analysis of oleo-resin by GC-MS showed that the major components were sesquiterpenes, namely α-gurjunene (30.31%), (-)-isoledene (13.69%), alloaromadendrene (3.28%), β-caryophyllene (3.14%), γ-gurjunene (3.14%) and spathulenol (1.11%). The cytotoxic activity of oleo-resin can be attributed to the sesquiterpene content, whereas the cytotoxic and antioxidant activities of leaf, bark and twig extracts correlated to total phenolic content.
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Amen-Chen, Carlos, Bernard Riedl, Xiang-Ming Wang, and Christian Roy. "Softwood Bark Pyrolysis Oil-PF Resols. Part 1. Resin Synthesis and OSB Mechanical Properties." Holzforschung 56, no. 2 (March 12, 2002): 167–75. http://dx.doi.org/10.1515/hf.2002.028.
Повний текст джерелаАнотація:
Summary Bark residues generated by the pulp and paper and wood industries represent a threat to the environment due to leaching of chemicals such as phenolics and resin acids which are being currently regulated by governments. Vacuum pyrolysis of resinous bark produces phenolic-rich oils which represent a potential raw material to replace petroleum-based phenol presently used in the formulation of wood adhesive resols. Resols with different levels of phenol replacement by phenolic pyrolysis oils, formaldehyde to phenolics molar ratios and sodium hydroxide to phenolics molar ratios were synthesized. Strandboards werepreparedandtheirmechanicalandphysicalpropertiessuchasmodulusofrupture(MOR),modulus of elasticity (MOE), dry and 2-hour boil internal bond (IB) and thickness swelling (TS) were evaluated. Homogeneous panels bonded with resins having 25 and 50% by wt of pyrolysis oils replacing phenol exhibited comparable mechanical properties to those of panels made with a commercial surface resin under the same pressing conditions. Three-layer panels made with resins having 50 % by wt phenol replacement in the surface and 25% by wt phenol replacement in the core had mechanical properties above the requirements specified by the Canadian Standards CSAO437.0-93 for OSB products.
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VETTER, Roland E., and Ana Paula Ribeiro BARBOSA. "MANGROVE BARK: A RENEWABLE RESIN SOURCE FOR WOOD ADHESIVES." Acta Amazonica 25, no. 1-2 (1995): 69–72. http://dx.doi.org/10.1590/1809-43921995252072.
Повний текст джерелаАнотація:
From four solutions tested to extract tannins from mangrove bark for wood adhesives, hot water is recommended. Hot water extracted 21.4% of formaldehyde-hydrochloric acid reactive polyphenols on oven-dry bark basis.
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Leggate, William, Maryam Shirmohammadi, Robert L. McGavin, Kerri Chandra, Mark Knackstedt, Lydia Knuefing, and Michael Turner. "Influence of wood’s anatomical and resin traits on the radial permeability of the hybrid pine (Pinus elliottii × Pinus caribaea) wood in Australia." BioResources 15, no. 3 (July 20, 2020): 6851–73. http://dx.doi.org/10.15376/biores.15.3.6851-6873.
Повний текст джерелаАнотація:
Wood permeability has a major effect on industrial wood processing and utilization. Wood anatomy and resin influence the permeability of wood. Understanding and manipulating these influences is important to optimize the manufacture and use of forest products. This study investigated the relationships between wood anatomical traits, radial permeability, and resin content of samples collected from 19-year-old hybrid pines (Pinus elliottii var. elliottii × Pinus caribaea var. hondurensis) from Queensland, Australia. The earlywood tracheid tangential lumen diameter and axial resin canal diameter were statistically positively correlated with radial permeability. The heartwood proportion and the frequency of axial resin canals were statistically negatively correlated with radial permeability and positively correlated with resin content. The axial resin canal diameter, sapwood proportion, latewood content, ray frequency, and earlywood tracheid lumen diameter increased from pith to bark, whereas the axial resin canal frequency decreased. Resin was found distributed throughout the wood microstructure, from pith to bark in many samples, and in both heartwood and sapwood. However, there was a much greater quantity of resin in heartwood and wood from the middle (inner radius) of the tree, with widespread occurrence of resin impregnation in the axial tracheids.
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Wermelinger, Beat, Andreas Rigling, Doris Schneider Mathis, Marc Kenis, and Martin M. Gossner. "Climate Change Effects on Trophic Interactions of Bark Beetles in Inner Alpine Scots Pine Forests." Forests 12, no. 2 (January 25, 2021): 136. http://dx.doi.org/10.3390/f12020136.
Повний текст джерелаАнотація:
Increased tree mortality has become a widespread phenomenon and is largely attributed to climate change. Little field research has addressed the complex interactions between trees, herbivores, and their natural enemies as affected by temperature. We recorded the densities of bark insects and their natural enemies emerging from felled trees in Scots pine forests at 17 study sites along 6 elevation gradients encompassing different temperature ranges in 3 regions in Switzerland and Italy. We additionally measured tree resin defense at different elevations. The density of aggressive bark beetles decreased with increasing temperatures while that of non-aggressive species did not respond to temperature. Contrasting patterns were also found for natural enemies, with the densities of most predatory taxa decreasing with increasing temperature whereas densities of parasitoids increased. Consequently, bark beetle mortality by predators decreased and that by parasitoids increased with temperature. Exudation of resin increased with temperature. As the number of resin ducts did not change with temperature, this is assumed a physical effect of reduced viscosity. Despite lower densities of aggressive bark beetles and improved tree resin flow under higher temperatures, the currently experienced drought-induced reduction in tree vigor is likely to increase tree mortality under the ongoing climate warming.
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Malca-García, Gonzalo Rodolfo, Lothar Hennig, Mayar Luis Ganoza-Yupanqui, Alejandro Piña-Iturbe, and Rainer W. Bussmann. "Constituents from the bark resin of Schinus molle." Revista Brasileira de Farmacognosia 27, no. 1 (January 2017): 67–69. http://dx.doi.org/10.1016/j.bjp.2016.07.004.
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Ruel, Jonathan J., Matthew P. Ayres, and Peter L. Lorio, Jr. "Loblolly pine responds to mechanical wounding with increased resin flow." Canadian Journal of Forest Research 28, no. 4 (April 1, 1998): 596–602. http://dx.doi.org/10.1139/x98-030.
Повний текст джерелаАнотація:
The oleoresin produced by many conifers has a deleterious effect on numerous associated herbivores, including bark beetles (Coleoptera: Scolytidae), and may have evolved as a plant defense mechanism. Three experiments with juvenile loblolly pine (Pinus taeda L.) used mechanical wounding to drain resin reserves and assess the effects of prior bark wounding on subsequent resin flow up to 7 days post-treatment. Resin flow returned to pre-treatment values within 2 days after wounding began and, in nearly every tree in each experiment, continued to increase on subsequent days. On average, resin flow reached double the pre-treatment values (mean ± SE: 2.10 ± 0.10 vs. 1.13 ± 0.10 g/3 h and 2.28 ± 0.09 vs. 0.90 ± 0.09 g/3 h for wounded vs. pre-treatment in experiments 1 and 2, respectively). Considering its timing and magnitude, this previously undescribed response may be important in modulating interactions between pine trees and bark beetles. In addition, resin flow following treatment was greater in trees in larger crown size classes (thinned > edge of stand = unthinned in experiment 1; edge of stand > thinned > unthinned in experiment 2). This may help explain why trees in thinned stands are less susceptible to southern pine beetle (Dendroctonus frontalis Zimm.) infestation than trees in unthinned stands.
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Prabowo, Herwidhi Tri, Sulhadi Sulhadi, Mahardika Prasetya Aji, and Teguh Darsono. "SIFAT MEKANIK BAHAN KOMPOSIT KAMPAS REM BERBAHAN DASAR SERBUK ARANG KULIT BUAH MAHONI." SPEKTRA: Jurnal Fisika dan Aplikasinya 2, no. 2 (October 17, 2017): 127. http://dx.doi.org/10.21009/spektra.022.06.
Повний текст джерелаАнотація:
Mahogany bark is one of natural material which not used optimally in society. The overabundance of mahogany bark appearing new problem of garbage which charges an alternative solution creatively and innovatively becomes a new efficient and effective product. An alternative solution of mahogany bark utilization is as organic composite material of disk brake. The making of organic composite material of brake disk firstly is reducing the mahogany bark becomes a homogeneous carbon powder. The mahogany bark was smoked being of carbon and mixed with coconut shell and resin polyester as an adhesive. The organic composite material was produced, tested by Brinell Hardness test and attrition test by varied of composition percentage. There are five kinds of composite material composition had been tested. The result is obtainable of the most precise composition percentage 60% mahogany bark carbon, 15% coconut shell carbon, and 25% resin polyester which has brinell hardness number and attrition massa identically with Standar Nasional Indonesia (SNI).
Keywords: mahogany bark, composite material, disk brake, Brinell hardness test, attrition test
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Khamphukdee, Charinya, Ibrahim Turkmani, Yutthana Chotritthirong, Yaowared Chulikhit, Chantana Boonyarat, Nazim Sekeroglu, Artur M. S. Silva, Orawan Monthakantirat та Anake Kijjoa. "Effects of the Bark Resin Extract of Garcinia nigrolineata on Chronic Stress-Induced Memory Deficit in Mice Model and the In Vitro Monoamine Oxidases and β-Amyloid Aggregation Inhibitory Activities of Its Prenylated Xanthone Constituents". Molecules 27, № 9 (7 травня 2022): 3014. http://dx.doi.org/10.3390/molecules27093014.
Повний текст джерелаАнотація:
The present study describes investigation of the effects of the bark resin extract of Garcinia nigrolineata (Clusiaceae) on the cognitive function and the induction of oxidative stress in both frontal cortex and hippocampus by unpredictable chronic mild stress (UCMS). By using behavioral mouse models, i.e., the Y-maze test, the Novel Object Recognition Test (NORT), and the Morris Water Maze Test (MWMT), it was found that the negative impact of repeated mild stress-induced learning and memory deficit through brain oxidative stress in the UCMS mice was reversed by treatment with the bark resin extract G. nigrolineata. Moreover, the prenylated xanthones viz. cowagarcinone C, cowaxanthone, α-mangostin, cowaxanthone B, cowanin, fuscaxanthone A, fuscaxanthone B, xanthochymusxanthones A, 7-O-methylgarcinone E, and cowagarcinone A, isolated from the bark resin of G. nigrolineata, were assayed for their inhibitory activities against β-amyloid (Aβ) aggregation and monoamine oxidase enzymes (MAOs).
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Wainhouse, D., J. Staley, J. Johnston, and R. Boswell. "The effect of environmentally induced changes in the bark of young conifers on feeding behaviour and reproductive development of adult Hylobius abietis (Coleoptera: Curculionidae)." Bulletin of Entomological Research 95, no. 2 (April 2005): 151–59. http://dx.doi.org/10.1079/ber2004344.
Повний текст джерелаАнотація:
AbstractYoung plants of Sitka spruce, Scots and Corsican pine were subject to high and low light, and high and low nitrogen treatments in a polyhouse experiment. The effect of treatments on resin duct size and nitrogen concentration in stem bark was determined together with feeding by Hylobius abietis Linnaeus on the stems of ‘intact’ plants and on ‘detached’ stems cut from the plant. Resin duct size was largest on Corsican pine and smallest on Sitka spruce and inherent variation in duct size between the three conifer species appears to determine the pattern of weevil feeding between species. Resin ducts and the flow of resin from them protect the stems of young conifers from weevil feeding not by affecting the total amount of bark eaten but by limiting the depth of feeding and so protecting the inner phloem and cambium. Shallow feeding may increase the likelihood of effective wound repair. Duct size was positively related to plant growth and in particular increased with bark thickness. Overall, ducts were largest in the high light treatment although species differed in their response to the treatment. It is suggested that the effects of plant size, growing conditions and transplantation on susceptiblilty to attack by H. abietis, reported in various studies, may be due to underlying variation in resin duct size or flow rate. The effect on weevils of super-ficial feeding on stems is to increase the time for reproductive maturation by reducing consumption of the inner bark which has a higher nitrogen content.
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Ishida, Kyoko, and Taizo Hogetsu. "Role of resin canals in the early stages of pine wilt disease caused by the pine wood nematode." Canadian Journal of Botany 75, no. 2 (February 1, 1997): 346–51. http://dx.doi.org/10.1139/b97-036.
Повний текст джерелаАнотація:
The role of cortical resin canals in the early development of a pine wilt disease in Japanese black pine, Pinus thunbergii, was studied. A part of the bark of a 2 cm long segment from a current-year stem was removed by a tangential cut with a razor blade. Both cortex-exposed segments with cut cortical resin canals (designated as +RC segments) and those without cut resin canals (–RC segments) were obtained by chance. When a virulent nematode isolate (S6-1) was inoculated onto the cut surface, the surface of the +RC segments turned brown 4 d after inoculation, and in some segments this browning occurred more intensely around cortical resin canals. When segments were cut transversely at the middle, the transverse cut surface of the inoculated +RC segments was brown and fragile, but that of the inoculated –RC segments was pale green and stable, as was that of the non-inoculated controls. Correspondingly, tissue cells including epithelial cells of the cortical resin canal of the +RC segments were all dead, but those of the –RC segments and the controls were alive. When nematodes were inoculated onto the inner surface (cambium side) of a bark peeling at which cambial xylem cells were exposed, they did not kill the cambial cells. When inoculated on the transverse cut end of a bark peeling from which nematodes would enter resin canals, nematodes killed all cells in the peeling. The above results indicate that nematodes do not kill cortical cells immediately after inoculation but become harmful to pine cells after living in cortical resin canals. Key words: Bursaphelenchus xylophilus, pine wilt disease, pine wood nematode, Pinus thunbergii, resin canal.
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Bakar, Balkis F. A., and Frederick A. Kamke. "Alkali Concentration and Diluent Effects on Properties of Grape Cane Fiber-Reinforced Polymer Composites." Polymers 13, no. 23 (November 23, 2021): 4055. http://dx.doi.org/10.3390/polym13234055.
Повний текст джерелаАнотація:
The main objective of this study was to investigate the properties of polymer composites reinforced with grape cane fibers. The fibers were subjected to a sodium hydroxide (NaOH) treatment at two treatment concentrations to extract the fibers as well as fiber surface treatment. Panels were fabricated by hand lay-up and compression molding according to different fiber types, namely outer bark (OB) and whole (W) fibers. The whole fiber was a mixture of OB and inner bark (IB) fibers. Grape cane fibers were used as the reinforcement material for unsaturated polyester (UPE) resin panels. Acrylated epoxidized soybean oil (AESO) was used as a reactive diluent material with the UPE resin, and the results were compared with panels prepared with commercial styrene–UPE. There were inconsistent alkali treatment concentration effects on the mechanical properties and water absorption. However, panels fabricated with the whole bark fibers that have been treated with 1 wt % NaOH and had AESO–UPE resin resulted in the best tensile and flexural strength.
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Slamet, W. Y., S. A. Faulina, A. Hidayat, A. Susilowati, D. Elfiati, L. M. Rahayu, and M. Turjaman. "Diversity of endophytic fungal species from Styrax benzoin found in benzoin-producing locations in North Sumatra." IOP Conference Series: Earth and Environmental Science 914, no. 1 (November 1, 2021): 012041. http://dx.doi.org/10.1088/1755-1315/914/1/012041.
Повний текст джерелаАнотація:
Abstract Styrax benzoin is a native tree to Indonesia, particularly in North Sumatra. This plant species produces benzoin resin, which is beneficial for medicinal treatments, hence its commercial value. Endophytic fungi help produce bioactive metabolites and contribute to resin production. However, the diversity of endophytic fungal species from S. benzoin grown in North Sumatra remained largely unexplored. This study aims to determine the distribution and diversity of culturable endophytic fungi from two kemenyan-producing locations in North Sumatra, Simalungun and North Tapanuli, as well as their tree part origin. A total of 7 and 8 endophytic fungal species were obtained from barks, stems, and/or leaves of S. benzoin grown in Simalungun and North Tapanuli, respectively, and identified by internal transcribed spacer sequence analysis. Endophytic fungi from North Tapanuli showed higher diversity, with a Shannon-Wiener index of 2.31 than those from Simalungun (1.95). Morisita-Horn similarity indices for bark-stem, stem-leaf, and bark-leaf were 0.47, 0.08, and 0, respectively, hinting at organ-specificity colonization. This study offers insights into the diversity of endophytic fungi isolated from S. benzoin which may contribute to future improvement of benzoin resin production.
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Popp, Michael P., Jon D. Johnson, and Thomas L. Massey. "Stimulation of resin flow in slash and loblolly pine by bark beetle vectored fungi." Canadian Journal of Forest Research 21, no. 7 (July 1, 1991): 1124–26. http://dx.doi.org/10.1139/x91-155.
Повний текст джерелаАнотація:
The passive flow of resin from wounds is one mechanism that pines, Pinus spp., use in the defense against bark beetles and the pathogenic fungi they vector. Ten 18- to 20-year-old slash pine, Pinuselliottii Engelm. var. elliottii, were inoculated with spores of Ceratocystisminor (Hedge.) Hunt or Ceratocystisips (Rumb.) C. Moreau, or treated with sterile water during August 1988 to determine if resin flow is stimulated by fungal inoculation. Resin flowing from wounds was collected every 24 h for 2 days. This study was repeated in August 1989 with both slash pine and loblolly pine, Pinustaeda L., and resin was collected every 24 h for 3 days. In both species resin flow did not differ significantly among treatments during the first 24 h. However, during the second 24-h period, resin flow from the fungal-inoculated wounds was significantly greater than the flow from the sterile water treated wound. This pattern continued during the third 24-h period for slash but not loblolly pine. These results suggest that resin flow is not entirely passive and exhibits a degree of inducibility.
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Herbst, Marcelo H., and Ney V. Vugman. "EPR Spectroscopy Investigation of Cu2+Ions Adsorbed in Tannin-Formaldehyde Resins of Mimosa (Acacia mearnsii) Bark Extracts." Journal of Spectroscopy 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/978270.
Повний текст джерелаАнотація:
The chemical environment of Cu2+ions adsorbed in tannin-formaldehyde resins ofAcacia mearnsiibark extracts, prepared from polybutene, is investigated by EPR spectroscopy at 300 K. The spectrum is simulated considering two isolated axial Cu(II) species (Species 1:A∥=16.50(5) mT,A⊥=1.20(10) mT,g∥=2.28(1), andg⊥=2.08(1); Species 2:A∥=15.00(5) mT,A⊥=1.50(10) mT,g∥=2.32(1), andg⊥=2.05(2)), superposed to a broad line (giso=2.14(1); linewidth = 30.0(5) mT) assigned to Cu(II) aggregates. Measurements at 77 K did not improve spectral resolution. Heating at 413 K changes the hyperfine parameters of Species 2 (A∥=14.20(5) mT,A⊥=1.20(10) mT,g∥=2.33(1), andg⊥=2.07(2)) and slightly modifies the parameters of the broad line (giso=2.11(2); linewidth = 40.00(50) mT) but does not change Species 1, assigned to Cu(II) species immobilized into resin pores in cathecolate-type coordination sites. Species 2 is assigned to Cu(II) species immobilized at the outer resin surface. Upon extended heating, a reversible formation of semiquinone-type paramagnetic radicals (giso=2.0037(1)) is observed, assigned to the partial collapse of the resin polymeric network.
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Amen-Chen, C., B. Riedl, and C. Roy. "Softwood Bark Pyrolysis Oil-PF Resols. Part 2. Thermal Analysis by DSC and TG." Holzforschung 56, no. 3 (April 29, 2002): 273–80. http://dx.doi.org/10.1515/hf.2002.045.
Повний текст джерелаАнотація:
Summary Cure behavior of resins formulated with petroleum phenol replaced by 25 and 50 wt% of softwood bark-derived pyrolysis oils, using various formaldehyde to phenolics molar ratios and alkalinity content, was characterized by Differential Scanning Calorimetry (DSC). Kinetic parameters were obtained by the Borchart-Daniels method and the model-free (Vyazovkin) method. Resins containing up to 50% by wt of pyrolysis oils had slower cure kinetics and lower extent of condensation reaction compared to a neat laboratory made phenol-formaldehyde resin. However, very similar kinetic curing behavior to the standard resins was found for resols having 25% by wt of the petroleum phenol replaced by the pyrolysis oils. Thermogravimetric analysis (TG) of cured pyrolysis oil-PF resins has been done under nitrogen and air environments at a constant heating rate. Thermal behavior of resins containing pyrolysis oils differed depending on the nature of the purge gas used in TG. Increasing the amount of pyrolysis oils decreased the thermal resistance of the experimental resins.
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Ichihara, Y., K. Fukuda, and K. Suzuki. "Early Symptom Development and Histological Changes Associated with Migration of Bursaphelenchus xylophilus in Seedling Tissues of Pinus thunbergii." Plant Disease 84, no. 6 (June 2000): 675–80. http://dx.doi.org/10.1094/pdis.2000.84.6.675.
Повний текст джерелаАнотація:
In order to clarify the mechanism of pine wilt caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus, nematode migration in tissues and disease symptoms in Pinus thunbergii seedlings were investigated. One-year-old seedlings were inoculated with different pathogenic isolates of PWN under two different temperatures. At an early stage of symptom development, a virulent isolate of PWN multiplied in both bark and xylem and was distributed in cortical resin canals, cortical tissue, and xylem resin canals at 30°C. Cell death and disease symptoms developed in both bark and xylem. The virulent isolate of PWN at 25°C and the avirulent isolate of PWN at 30°C were distributed mainly in cortical resin canals, but rarely in xylem resin canals and cortical tissue. Disease symptoms and cell death occurred in cortical resin canals and rarely occurred in other tissues. These results demonstrated that the virulent isolate of PWN at low temperature and avirulent nematodes could not easily migrate to xylem resin canals and cortical tissue. It was shown that cell death and early symptom development coincided with PWN migration and, therefore, PWN invasion induces cell death and early symptom development.
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Tudor, Eugenia Mariana, Anna Dettendorfer, Günther Kain, Marius Catalin Barbu, Roman Réh, and Ľuboš Krišťák. "Sound-Absorption Coefficient of Bark-Based Insulation Panels." Polymers 12, no. 5 (April 29, 2020): 1012. http://dx.doi.org/10.3390/polym12051012.
Повний текст джерелаАнотація:
The objective of this study was to investigate the sound absorption coefficient of bark-based insulation panels made of softwood barks Spruce (Picea abies (L.) H. Karst.) and Larch (Larix decidua Mill.) by means of impedance tube, with a frequency range between 125 and 4000 Hz. The highest efficiency of sound absorption was recorded for spruce bark-based insulation boards bonded with urea-formaldehyde resin, at a level of 1000 and 2000 Hz. The potential of noise reduction of larch bark-based panels glued with tannin-based adhesive covers the same frequency interval. The experimental results show that softwood bark, an underrated material, can substitute expensive materials that involve more grey energy in sound insulation applications. Compared with wood-based composites, the engineered spruce bark (with coarse-grained and fine-grained particles) can absorb the sound even better than MDF, particleboard or OSB. Therefore, the sound absorption coefficient values strengthen the application of insulation panels based on tree bark as structural elements for the noise reduction in residential buildings, and concurrently they open the new ways for a deeper research in this field.
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Valor, Teresa, Sharon M. Hood, Míriam Piqué, Asier Larrañaga, and Pere Casals. "Resin ducts and bark thickness influence pine resistance to bark beetles after prescribed fire." Forest Ecology and Management 494 (August 2021): 119322. http://dx.doi.org/10.1016/j.foreco.2021.119322.
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De Magistris, Alberto Antonio, and María Agueda Castro. "BARK ANATOMY OF SOUTHERN SOUTH AMERICAN CUPRESSACEAE." IAWA Journal 22, no. 4 (2001): 367–83. http://dx.doi.org/10.1163/22941932-90000383.
Повний текст джерелаАнотація:
Anatomical and macroscopic features of the bark are described for the Cupressaceae indigenous to southern South America: Austrocedrus chilensis, Fitzroya cupressoides and Pilgerodendron uviferum. Macroscopically there are two different types: 1) with rather deep longitudinal and transverse fissures, and short ridges or scales varying in adherence (Austrocedrus); and 2) with deep fissures, and elongate and wide ridges, which contain the rhytidome accumulated over several years (Fitzroya and Pilgerodendron). The pattern of the secondary phloem of the three species studied agrees closely with that of the other genera of Cupressaceae, but there are diagnostic differences as well: arrangement of the fibre rows, fibre types, frequency of resin ducts and the ray height. Pilgerodendron uviferum shows rays with erect marginal cells, similar to Strasburger cells, whereas ray sclereids in the fibre crossing zones were only observed in Austrocedrus. Resin ducts are present in Austrocedrus and Fitzroya. The main characteristics are used for an identification key. Anatomical relations with other genera of the family are discussed.
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DeRose, R. Justin, Matthew F. Bekker, and James N. Long. "Traumatic resin ducts as indicators of bark beetle outbreaks." Canadian Journal of Forest Research 47, no. 9 (September 2017): 1168–74. http://dx.doi.org/10.1139/cjfr-2017-0097.
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Смидракова, Mariya Smidrakova, Седлячик, and Yan Sedlyachek. "Cellulose sludge and wood bark as formaldehyde scavengers for plywood bonded with urea formaldehyde resin." Forestry Engineering Journal 6, no. 4 (May 3, 2017): 187–93. http://dx.doi.org/10.12737/23456.
Повний текст джерелаАнотація:
The aim of the research was to modify urea-formaldehyde resin (UF) by cellulose sludge and wood bark in order to reduce formaldehyde emission. Wood bark powder was a mixture containing 50 % of beech bark and 50 % of spruce bark. Release of formaldehyde and shear strength of the adhesive joints was tested on five resp. three-layer alder plywood. Formaldehyde emission was determined by 24-hour desiccator method and monitored during seven weeks after gluing. After 7 weeks of the experiment the reference UF adhesive showed formaldehyde emission decreased by 39 %.
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Gref, Rolf, and Anders Ericsson. "Wound-induced changes of resin acid concentrations in living bark of Scots pine seedlings." Canadian Journal of Forest Research 15, no. 1 (February 1, 1985): 92–96. http://dx.doi.org/10.1139/x85-017.
Повний текст джерелаАнотація:
One-year-old Pinussylvestris (L.) seedlings were wounded at the stem base by stripping off stem bark pieces of approximately 10 mm in length and covering about 50% of the stem circumference. The seedlings were thereafter planted out in the field or in a climate chamber. The field experiment was repeated on four different planting dates. Wounded and control seedlings were successively harvested for gas chromatographic determination of changes in resin acid concentrations of the bark surrounding the wounded area. Independent of planting date, wounded seedlings were found to have higher concentrations of total resin acids than corresponding controls. The most important quantitative changes in resin acids were observed for isopimaric, levopimaric + palustric, dehydroabietie, abietic, and neoabietic acid. In wounded seedlings the concentration of dehydroabietic acid showed the most significant increase, both in the field and in climate chamber experiments. This increase was rapid and appeared within 1 week in the field and within 3 days in the climate chamber. The other resin acids identified showed a somewhat similar variation pattern, but the differences were not as distinct as for dehydroabietic acid. These wound-induced rapid changes in resin acid concentrations could be important for resistance to pathogens.
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Davis, Ryan S., Sharon Hood, and Barbara J. Bentz. "Fire-injured ponderosa pine provide a pulsed resource for bark beetles." Canadian Journal of Forest Research 42, no. 12 (December 2012): 2022–36. http://dx.doi.org/10.1139/x2012-147.
Повний текст джерелаАнотація:
Bark beetles can cause substantial mortality of trees that would otherwise survive fire injuries. Resin response of fire-injured northern Rocky Mountain ponderosa pine ( Pinus ponderosa Douglas ex P. Lawson & C. Lawson) and specific injuries that contribute to increased bark beetle attack susceptibility and brood production are unknown. We monitored ponderosa pine mortality and resin flow and bark beetle colonization and reproduction following a prescribed fire in Idaho and a wildfire in Montana. The level of fire-caused tree injury differed between the two sites, and the level of tree injury most susceptible to bark beetle attack and colonization also differed. Strip-attacked trees alive 3 years post-fire had lower levels of bole and crown injury than trees mass attacked and killed by bark beetles, suggesting that fire-injured trees were less well defended. Brood production of western pine beetle ( Dendroctonus brevicomis LeConte) did not differ between fire-injured and uninjured trees, although mountain pine beetle ( Dendroctonus ponderosae Hopkins) brood production was low in both tree types, potentially due to competition with faster developing bark beetle species that also colonized trees. Despite a large number of live trees remaining at both sites, bark beetle response to fire-injured trees pulsed and receded within 2 years post-fire, potentially due to a limited number of trees that could be easily colonized.
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Xing, C., S. Y. Zhang, and J. Deng. "Effect of wood acidity and catalyst on UF resin gel time." Holzforschung 58, no. 4 (July 7, 2004): 408–12. http://dx.doi.org/10.1515/hf.2004.061.
Повний текст джерелаАнотація:
Abstract Knowledge of pH and buffering capacity of raw fiber materials is important for understanding the effects of raw material on the curing rate of urea formaldehyde (UF) resin, used for panel manufacturing, especially with some less-desirable wood materials such as bark, top, and commercial thinnings. The effects of pH and buffering capacity as well as catalyst content on the gel time of UF resin were investigated. The results obtained from this study indicate that bark has a lower pH value as well as higher acid and alkaline buffering capacities than wood of the same species due to their extractives. The pH values of the raw fiber materials studied decrease with increased absolute and relative acid buffering capacity due to the increased absolute acidity mass in the solution. At lower levels of added catalyst, the effect of raw material pH on UF resin gel time is significant, while it is insignificant at higher catalyst contents. This may be due to the acidity of wood, which is the main acid catalyst source of the mixture at lower levels of added catalyst, while at higher levels, catalyst is the main source. With higher catalyst contents, all studied raw materials mixed with UF resin result in a longer gel time than does UF resin alone.
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Kelsey, Rick G., Eric D. Forsman, and James K. Swingle. "Terpenoid Resin Distribution in Conifer Needles with Implications for Red Tree Vole, Arborimus longicaudus, Foraging." Canadian Field-Naturalist 123, no. 1 (January 1, 2009): 12. http://dx.doi.org/10.22621/cfn.v123i1.670.
Повний текст джерелаАнотація:
Tree voles are dietary specialists, feeding almost exclusively on conifer needles and bark. They reduce their exposure to conifer chemical defenses by physically removing resin ducts from many needles before ingesting the remaining tissue. The portion of needle removed differs among tree species, depending on the location of the resin ducts. To evaluate the amount of resin avoided by this behavior we removed the resin ducts from Douglas-fir, Western Hemlock, and Sitka Spruce needles and used gas chromatography to compare volatile resin concentrations in needles with and without the resin ducts removed. Needle tissues without resin ducts contained no terpenoid resin, demonstrating that tree voles can regulate the nutritional quality of their diet by controlling the amount of resin ingested. We suggest that differences in the physical structure (and possibly chemical composition of terpenes) of the needles make it difficult for voles to easily switch between tree hosts.
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Moeck, Henry A., and Clarence S. Simmons. "PRIMARY ATTRACTION OF MOUNTAIN PINE BEETLE, DENDROCTONUS PONDEROSAE HOPK. (COLEOPTERA: SCOLYTIDAE), TO BOLTS OF LODGEPOLE PINE." Canadian Entomologist 123, no. 2 (April 1991): 299–304. http://dx.doi.org/10.4039/ent123299-2.
Повний текст джерелаАнотація:
AbstractThree field tests were conducted in which fresh lodgepole pine (Pinus contorta Douglas var. latifolia Engl.) material, namely bolts with and without bark, bark only, and freshly tapped resin, were placed in beetle-excluding “greenhouse” cages; empty cages served as controls. Two “window” flight traps per cage, at right angles to each other, caught mountain pine beetles (Dendroctonus ponderosae Hopkins) arriving at the cages. Significantly more mountain pine beetles were trapped at cages baited with bolts and wood only than at empty control cages. Primary attraction in the mountain pine beetle is thus established, in the absence of pheromones and normal visual cues (tree stem silhouette). More beetles were trapped at cages baited with bark only and with resin than at empty control cages, but differences were not significant at p = 0.05. The sex ratio of trapped beetles (4.83 females: 1 male) was more than twice as high as the reported sex ratios of free-flying and emerging beetles.
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Netherer, Sigrid, Magdalena Ehn, Emma Blackwell, and Thomas Kirisits. "Defence reactions of mature Norway spruce (Picea abies) before and after inoculation of the blue-stain fungus Endoconidiophora polonica in a drought stress experiment." Forestry Journal 62, no. 4 (December 1, 2016): 169–77. http://dx.doi.org/10.1515/forj-2016-0014.
Повний текст джерелаАнотація:
Abstract We performed an inoculation experiment using the blue-stain fungus Endoconidiophora polonica at the Rosalia Roof study site, which was set up to study drought effects on Norway spruce susceptibility to attacks by the European spruce bark beetle Ips typographus. Tree resistance parameters such as resin flow rate and extent of hypersensitive wound reaction in the phloem were investigated prior to and after fungal infection. Sample trees with different drought treatments (trees fully covered or semi-covered by roofs, control trees) were inoculated with E. polonica in July 2014. In order to check for areas of phloem necrosis, the outer bark around the inoculation holes was scratched off 6 weeks later. We recorded the amount of resin exudation within 12 hours overnight in August and September 2013 and 2014. Although wound reaction zones did not differ in size between tree collectives of the various treatments, fully covered trees tended to exhibit larger necrotic areas compared to control trees. The least water supplied trees showed lowest resin flow rates prior to fungal inoculation, but were the only group to show significantly enhanced resin flow five weeks after the evaluation of defence reactions. Our results agree with earlier findings that wounding and few fungal inoculations can increase tree resistance in the medium term given not too severe water stress. Further investigations will clarify how water stress affects the availability of non-structural carbohydrates for secondary metabolism, when depletion of resources eventually occurs, and at which point trees are most susceptible to bark beetle attack.
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Marcotullio, Maria Carla, Ornelio Rosati, and Daniela Lanari. "Phytochemistry of Commiphora erythraea: A Review." Natural Product Communications 13, no. 9 (September 2018): 1934578X1801300. http://dx.doi.org/10.1177/1934578x1801300925.
Повний текст джерелаАнотація:
Commiphora erythraea (Burseraceae) resin derives from the bark injury of the plant, a small tree native to the Arabian Peninsula. The resin is commonly known as myrrh and it is traditionally used to protect livestock from ticks and to treat diseases related to inflammation. The resin is constituted by a volatile and a non-volatile fraction. The volatile fraction is a source of furanosesquiterpenoids among which furanodienone showed to be the most promising pharmacological active compound. The composition and pharmacological activities of the extracts and the isolated compounds have been reviewed.
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Abduh, Muhammad Yusuf, Ananda Teli Rahmanita, Elga Ridho Maulana, Valenikhe Fitri Nadhira, Tjokorda Istri Indira, and Robert Manurung. "Valorization of Lower Grade Resin, Bark, and Fruit of Styrax Sumatrana." International Journal of Innovative Research and Scientific Studies 5, no. 1 (February 9, 2022): 30–36. http://dx.doi.org/10.53894/ijirss.v5i1.349.
Повний текст джерелаАнотація:
Styrax sumatrana or the kemenyan tree grows in North Sumatera, Indonesia, and its resin is commonly utilized by the local community. Other parts of kemenyan, such as barks and fruits contain valuable compounds that can be extracted to produce high-value bioproducts. This study examined the effect of different resin grades on the physical parameters and cinnamic acid content, delignification pre-treatment period of kemenyan barks with Phanerocahete chrysosporium on the amount of extracted saponin from the barks, and different fruit ripeness on the composition of the fruits. This study showed that grade IV, V and VI resin contain 21.78 to 24.89% cinnamic acid. The isolated cinnamic acid had a purity of 90.9 to 94.3%. Pre-treatments of kemenyan barks were able to degrade 15% of the lignin after 21 days of incubation with Phanerochaete chrysosporium. and increased the amount of extracted saponin up to 7.5-fold higher compared to the non-pre-treated barks. Ripe kemenyan fruits had a higher protein (4.27-10.23%) and crude fat (0.91-7.36%) content as compared to the unripe fruits. Fatty acid composition of the crude fat had been determined and primarily consists of linoleic acid (31.71-42.33%) and palmitic acid (30.44-30.82%) for both ripe and unripe fruits.
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Sousa, Joana L. C., Patrícia A. B. Ramos, Carmen S. R. Freire, Artur M. S. Silva, and Armando J. D. Silvestre. "Chemical Composition of Lipophilic Bark Extracts from Pinus pinaster and Pinus pinea Cultivated in Portugal." Applied Sciences 8, no. 12 (December 11, 2018): 2575. http://dx.doi.org/10.3390/app8122575.
Повний текст джерелаАнотація:
The chemical composition of lipophilic bark extracts from Pinus pinaster and Pinus pinea cultivated in Portugal was evaluated using gas chromatography-mass spectrometry. Diterpenic resin acids were found to be the main components of these lipophilic extracts, ranging from 0.96 g kg−1 dw in P. pinea bark to 2.35 g kg−1 dw in P. pinaster bark. In particular, dehydroabietic acid (DHAA) is the major constituent of both P. pinea and P. pinaster lipophilic fractions, accounting for 0.45 g kg−1 dw and 0.95 g kg−1 dw, respectively. Interestingly, many oxidized compounds were identified in the studied lipophilic extracts, including DHAA-oxidized derivatives (7-oxo-DHAA, 7α/β-hydroxy-DHAA, and 15-hydroxy-DHAA, among others) and also terpin (an oxidized monoterpene). These compounds are not naturally occurring compounds, and their formation might occur by the exposure of the bark to light and oxygen from the air, and the action of micro-organisms. Some of these compounds have not been previously reported as lipophilic constituents of the bark of the referred pine species. Other constituents, such as aromatic compounds, fatty acids, fatty alcohols, and sterols, are also present in the studied extracts. These results can represent an opportunity to valorize P. pinaster and P. pinea by-products as a primary source of the bioactive resin acids that are integrated into the current uses of these species.
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Noviyanti, Amalia, I. Wayan Arya Krishnawan Firdaus, and Rahmad Arifin. "THE EFFECT OF IRONWOOD STEM BARK EXTRACT (Eusideroxylon zwageri) ON THE GROWTH OF Streptococcus mutans ON ACRYLIC RESIN DENTURE PLATE." Dentino : Jurnal Kedokteran Gigi 6, no. 1 (May 11, 2021): 13. http://dx.doi.org/10.20527/dentino.v6i1.10634.
Повний текст джерелаАнотація:
ABSTRACTBackground: Streptococcus mutans is plaque-forming initiator bacteria. Plaque on the surface base of denture can cause color changing, bad breath, inflammation, and infection called denture stomatitis. Denture hygiene must be maintained by denture soaking in 0.2% chlorhexidine gluconate. However, 0.2% chlorhexidine gluconatethat used incessantly can cause side effects such as the changing of denture color and the fading of denture base pigmentation. The ironwood stem bark extract can be an alternative for denture cleanser material. Objectives: To analyze the effect of ironwood stem bark extract on the growth of Streptococcus mutans on heat cured type acrylic resin denture plate. Methods: True experimental laboratories research was used with post test only control group design using 9 treatment groups which are 5%, 10%, 20%, 40%, 60%, 80%, 100% concentration of ironwood stem bark extract, 0.2% chlorhexidine gluconate and aquadest. The treatment was performed with 3 times repetition resulting in 27 total samples. Antibacterial activity was measured by calculating the bacteria colony number. Results: The 5% and 10% concentration of ironwood stem bark extract were effective in reducing Streptococcus mutans with30.3 CFU/ml and 10.3 CFU/ml average colony number. The ironwood stem bark extracts with 20%, 40%, 60%, 80%, 100% concentration are effective and equivalent to 0.2% chlorhexidine gluconate against Streptococcus mutans with 0 CFU/ml average value. Conclusion: The 20%, 40%, 60%, 80%, 100% concentration of ironwood stem bark extract is equally effective as 0.2% chlorhexidine gluconatein killing Streptococcus mutans,exhibiting potential to be an alternative for denture cleanser material.Keyword: 0.2% Chlorhexidine gluconate, ironwood stem bark extract, acrylic resin denture plate heat cured type, Streptococcus mutans.
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Madar, Zion, and Nili Liphschitz. "Historical Studies of Cupressus Sempervirens L. Affected by Diplodia Pinea f. sp. Cupressi and Seiridium Cardinale." IAWA Journal 10, no. 2 (1989): 183–92. http://dx.doi.org/10.1163/22941932-90000487.
Повний текст джерелаАнотація:
Between 1980 and 1986 two serious diseases of Cupressus sempervirens were found in Israel: Seiridium cardinale and Diplodia pinea. Visual symptoms of both pathogens are similar and are eharaeterised by eanker formation aeeompanied by strong resin secretion from lesions. Histologieal examinations in the eentre of the eanker revea1 similar reaetions of C. sempervirens to Seiridium and Diplodia inoculation. Numerous resin duets are formed in the bark, necrophyllaetie periderm formation oceurs several months after inoculation, disorganisation of the xylem is eonspieuous, produetion of abnormal lignified parenehyma eells instead of traeheids oceur at the injured site, and eurved traeheids and transverse walls are formed. Tannin aeeumulation oceurs in the bark and xylem. Similar reaetions of C. sempervirens to wounding and similar effects of Matsucoccus josephi on Pinus halepensis are diseussed.
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Lu, Kun-Tsung, and Lang-Yue Wu. "Substitution of phenol in phenol-formaldehyde (PF) resins by wood tar for plywood adhesives." Holzforschung 67, no. 4 (May 1, 2013): 413–19. http://dx.doi.org/10.1515/hf-2012-0047.
Повний текст джерелаАнотація:
Abstract Wood tars from Acacia confusa Merr. and Cryptomeria japonica D. Don. were produced by reduced pressure distillation at 76 mm Hg and 50°C from the bottom layer of crude wood vinegars that had set for over 6 months. The feasibility of using water-soluble, resole-type, wood tar phenol-formaldehyde resins (WT-PF) was investigated. The resins were prepared from phenol (P) and wood tars (WTs) at weight ratios of 100:0, 80:20, 60:40 and 40:60 and F/P molar ratios of 1.5, 1.8 and 2.0 as plywood adhesives. The results demonstrated that WT-PF resins had a higher viscosity, shorter gel times, a higher polydispersity, a lower curing temperature and less heat of curing than conventional PF resins under the same conditions. The shear strength of plywood bonded with WT-PF resins was slightly lower than that of conventional PF resin. However, the WT-PF resin still met the CNS 1349 requirement for the dry test, and phenol substitution levels could be up to 60%, but only 20% for type I and type II plywood. The addition of A. confusa bark powder fillers could significantly improve the bonding strength of WT-PF resins, especially for the warm water soaking and soaking in boiling water tests. The required amounts of fillers added were up to 5% for A. confusa WT-PF resins and up to 3% for C. japonica resins.
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PÁSZTORY, Zoltán, Katalin HALÁSZ, Zoltán BÖRCSÖK, and Suthon SRIVARO. "Properties of High Density Fiberboard Mixed with Poplar Bark." Walailak Journal of Science and Technology (WJST) 17, no. 12 (December 1, 2020): 1286–93. http://dx.doi.org/10.48048/wjst.2021.6497.
Повний текст джерелаАнотація:
Formaldehyde in the indoor air is one of the chemicals which can cause health risk; therefore, researchers have strived to reduce formaldehyde emissions from different wood products. There are many chemical compounds in bark, including tannins, which can react with formaldehyde. The aim of this study was to reduce the formaldehyde emissions from HDF by mixing poplar bark powder into the raw material. 2, 4, 6, and 8 % (based on dry weight) Populus×euramericana bark was mixed with fibers, and HDF panels were manufactured with urea-formaldehyde resin. Mechanical properties, color change, and formaldehyde release were measured. Contrary to expectations, the mixed bark did not reduce formaldehyde emissions, but the mechanical properties deteriorated due to the bark powder. Formaldehyde emissions were reduced only in the case of 2 % added bark; in cases of 4, 6, and 8 %, the emissions increased.
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Chen, Hua, Mark E. Harmon, and Robert P. Griffiths. "Decomposition and nitrogen release from decomposing woody roots in coniferous forests of the Pacific Northwest: a chronosequence approach." Canadian Journal of Forest Research 31, no. 2 (February 1, 2001): 246–60. http://dx.doi.org/10.1139/x00-167.
Повний текст джерелаАнотація:
Decomposition of woody roots in Sitka spruce (Picea sitchensis (Bong.) Carrière), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and ponderosa pine (Pinus ponderosa P. Laws. ex C. Laws.) dominated forests in Oregon, U.S.A. was studied using a chronosequence. Roots of five coniferous species were excavated from stumps with ages up to 46 years old. In order of increasing decomposition rate constant (k) the species were Douglas-fir < Sitka spruce < lodgepole pine (Pinus contorta Dougl. ex Loud.) < western hemlock (Tsuga heterophylla (Raf.) Sarg) < ponderosa pine. Variation in the proportion of bark, wood, and resin cores was correlated to these differences. Root wood showed the highest k, root bark the second, and resin cores the lowest. The occurrence of resin cores in woody roots of Douglas-fir, Sitka spruce, and lodgepole pine greatly slowed the decomposition of these species. White rots occurred frequently in ponderosa pine and lodgepole pine, whereas brown rots mostly appeared in Douglas-fir and Sitka spruce. Species with white rot had a higher k than those with brown rot. Decomposing woody roots started to release N after 2030% mass loss, a point when the dead root C/N ratio averaged 140.
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Braz, P. V. F., A. A. Leme-Kraus, B. Aydin, J. W. Nam, R. Phansalkar, S. N. Chen, G. Pauli, and A. K. Bedran-Russo. "Effect of pine bark proanthocyanidins on dentin and resin–dentin interfaces." Dental Materials 32 (2016): e68-e69. http://dx.doi.org/10.1016/j.dental.2016.08.143.
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Nunes, Elsa, Teresa Quilhó, and Helena Pereira. "Anatomy and Chemical Composition of Pinus Pinaster Bark." IAWA Journal 17, no. 2 (1996): 141–50. http://dx.doi.org/10.1163/22941932-90001444.
Повний текст джерелаАнотація:
The secondary phloem of Pinus pinaster Aiton bark has sieve cells and axial and radial parenchyma, but no fibres. Resin ducts are present in fusiform rays . Stiloid crystals, starch granules and tannins occur inside sieve and parenchyma cells. The rhytidome of P. pinaster bark has a variable number of periderms forming scale-type discontinuous layers over expanded parenchyma cells. Phellem comprises 4-6 layers of thickwaIled and little suberized cells and phelloderm a layer of 2 or 3 thickened lignified ceIls and a layer of expanded cells.