• Title/Summary/Keyword: Larch

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Effect of Diluted H2SO4 and NaOH Treatment on Chemical Composition of Larch and Yellow Poplar (황산 및 수산화나트륨처리가 낙엽송과 백합나무의 주요 화학조성에 미치는 영향)

  • Lee, Soo-Min;Lee, A-Ram;Ahn, Byoung Jun;Kim, Yong Sik;Yang, In;Cho, Sung Taig
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.4
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    • pp.358-373
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    • 2013
  • In this study, both mild acid and alkali treatments with 1.0 wt% and 2.0 wt% of $H_2SO_4$ and NaOH solution were applied to evaluate the effects on chemical compositions of wood biomass. Yellow poplar (Liriodendron tulipifera L.) and larch (Larix kaempferi C.) were chosen due to major species planted in Korea. Chemical treatments of biomass were carried out by being soaked in either acid or alkali solution with 1:20 ratio for 72 hours at ambient temperature. Afterward, lignin, 5 major reduced sugars, ash contents and elemental composition were determined. To statistically understand the relationship between samples and chemical treatments, the Tukey test, simple linear regression model and ANOVA analysis were introduced using a statistical software R. As results from both wet chemistry and statistical analysis, yellow poplar was more affected on the lignin and xylose contents by acid treatments under these experimental conditions. Meanwhile, larch was more affected on the composition of galactose and lignin by alkali treatments. A series of results in this study would show that equivalent chemical treatment makes a change the chemical composition of each species.

Wood Pellet Production using Domestic Forest Thinning Residues and their Quality Characteristics (국내 숲가꾸기산물을 이용한 목재펠릿의 제조와 품질)

  • Ahn, Byoung-Jun;Kim, Yong Sik;Lee, Oh-Kyu;Cho, Sung-Taig;Choi, Don Ha;Lee, Soo Min
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.4
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    • pp.346-357
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    • 2013
  • In this study, it was conducted to produce wood pellets using domestic forest thinning residues and examine their quality according to Korean pellet quality standard. Raw materials were composed of larch and mixed broad leaves species. Based on the small-end diameter (6 cm), they were classified into four different types of raw materials such as LM (larch with middle diameter), LS (larch with small diameter), MM (mixed broadleaf with middle diameter), and MS (mixed broadleaf with small diameter). After crushing and drying process, wood pellets were produced by a ring-die type pelletizer using each raw material. Wood pellets made from four different types of raw materials were tested for their quality such as calorific value, moisture content, ash content, inorganic matters and so on. As results of quality analysis, the calorific values of all wood pellets were higher than 198 kcal/kg, and satisfied with the first grade of Korea wood pellet standard. The ash content was slightly increased after pelletizing. Mechanical durability of wood pellets was highly dependent on the types of raw materials. The quality differences among wood pellets were turned out due to different physical and chemical characteristics of raw materials even though the same pelletizing condition was applied.

Evaluation of Surface Emission and Internal Movement of Water in Japanese Larch Lumber (낙엽송재 내 수분의 내부이동 및 표면방사 평가)

  • Han, Yeongjung;Eom, Changdeuk;Kim, Se Jong;Kang, Wook;Park, Joo Saeng;Park, Moon Jae;Yeo, Hwanmyeong
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.4
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    • pp.1-8
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    • 2007
  • Japanese larch specimens with dimension of 2.5 (radial direction) ${\times}$ 2.5 (tangential direction) ${\times}$ 2.5 cm (longitudinal direction) were prepared to determine 3 different directional internal moisture movement coefficients and surface emission coefficients along the radial-, the tangential-, and the tangential-direction. 4 sides of each cubic specimen were wrapped with paraffin tape and rubber tape, leaving open the 2 opposite surfaces of interest, to provide one dimensional moisture movement during drying. The coefficients were determined at three different temperatures, 70, 50 and $30^{\circ}C$ and at two different relative humidities, 30 and 60%. Internal moisture movement coefficients inclusive of flow of free water and diffusion of bound water and water vapor were increased in the high temperature condition. The internal moisture movement coefficient in the longitudinal direction was about six times of those in transverse directions with radial value being 20% greater than the tangential. Surface emission coefficients were increased with temperature and decreased with surface moisture content. Using this results, moisture content (MC) profile and quantities of moisture evaporating in Japanese larch lumber could be predicted in dynamic drying situations.

Frequency and Wood Decaying Ability of Butt-rot Fungig Isolated form Larch (Larix leptolepis) (낙엽송근주심재부후병균(根株心材腐朽病菌)의 분포빈도(分布貧道)와 목재열화능력(木材劣化能力))

  • Kim, Hyun Joong;Cha, Ju Youngl;Yi, Chang Keun
    • Journal of Korean Society of Forest Science
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    • v.80 no.3
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    • pp.311-316
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    • 1991
  • Butt-rot fungi were isolated from decayed portion in butt rotted larch trees[Larix leptolepis(Sieb. et Zucc.) Gord.]. From a total of 216 affected trees in 38 forests of five provinces, Sparassis crispa(Wulf. ex Fr.) Fr. was isolated with the highest frequency, i.e.. 28% of the total trees. Laetiporus sulphureus(Fr.) Bond. et Sing, with 19%, and Phaeolus schweinitzii(Fr.) Pat. with 8%. However, none of these fungi was isolated from 45% of the trees. Wood decaying abilities and interaction of four basidiomycetous and three non-basidiomyo:etous fungi isolated from butt rotted trees were investigated. The weight loss of larch wood blocks, when exposed to the culture of a fungus for six months, was 19.6% for P. schweinitzii, 10% for S. crispa, 8.2% for L. sulphurous, 5.1% for Coriolus hirsutus, and less than 4.4% for three non-basidiomycetous fungi. In incubation with combinations of the fungi, the wood decay activity of S. crispa, L. sulphurous and C. hirsutus was increased by the non-basidiomycetous fungi of Geotrichum candidacy, G. sp. and Verticillium sp., but that of P. schweinitzii was not.

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Estimation of Radio Frequency Electric Field Strength for Dielectric Heating of Phenol-Resorcinol-Formaldehyde Resin Used for Manufacturing Glulam (구조용 집성재 제조용 접착제(Phenol-Resorcinol-Formaldehyde Resin) 유전 가열을 위한 고주파 전기장 세기 추산)

  • Yang, Sang-Yun;Han, Yeonjung;Park, Yonggun;Eom, Chang-Deuk;Kim, Se-Jong;Kim, Kwang-Mo;Park, Moon-Jae;Yeo, Hwanmyeong
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.3
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    • pp.339-345
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    • 2014
  • For enhancing productivity of glulam, high frequency (HF) curing technique was researched in this study. Heat energy is generated by electromagnetic energy dissipation when HF wave is applied to a dielectric material. Because both lamina and adhesives have dielectric property, internal heat generation would be occurred when HF wave is applied to glulam. Most room temperature setting adhesives such as phenol-resorcinol-formaldehyde (PRF) resin, which is popularly used for manufacturing glulam, can be cured more quickly as temperature of adhesives increases. In this study, dielectric properties of larch wood and PRF adhesives were experimentally evaluated, and the mechanism of HF heating, which induced the fast curing of glue layer in glulam, was theoretically analyzed. Result of our experiments showed relative loss factor of PRF resin, which leads temperature increase, was higher than that of larch wood. Also, it showed density and specific heat of PRF, which are resistance factors of temperature increase, were higher than those of wood. It was expected that the heat generation in PRF resin by HF heating would occur greater than in larch wood, because the ratio of relative loss factor to density and specific heat of PRF resin was greater than that of larch wood. Through theoretical approach with the experimental results, the relative strengths of ISM band HF electric fields to achieve a target heating rate were estimated.

Cultivation characteristics and yield of Sparassis latifolia depend on the substrate mixture (꽃송이버섯(Sparassis latifolia) 생육배지 조성에 따른 재배특성 및 수량)

  • Heo, Byong-Soo;Choi, Kyu-Hwan;Jo, Yeong-Min
    • Journal of Mushroom
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    • v.20 no.2
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    • pp.61-68
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    • 2022
  • We investigated the standard cultivation substrate for Sparassis latifolia "Neowul" bred in Jeollabuk-do Agricultural Research and Extension Services. Cultivation characteristics and yield were assessed by varying the kind of sawdust and additives, and the mixing ratio. The cultivation period in larch sawdust was the shortest at 97 days. The yield was excellent (143.6 g). The findings indicated that larch is a tree species appropriate for the cultivation of S. latifolia. When the additives were varied, the yield and productivity (53.1%) were highest (116.6 g) for the wheat bran treatment. Thus, wheat bran would be an additive appropriate for culturing S. latifolia. Concerning the use of different mixing ratios, larch sawdust:beet-pulp:wheat bran ratios of 80:15:5 and 85:10:5 resulted in yields of 114.4 g and 111.4 g, and productivity of 52.5% and 51.8%, respectively. These yield and productivity values were not statistically different. Thus, the standard cultivation substrate for S. latifolia can comprise larch sawdust, beet pulp, and wheat bran at a ratio of 80:15:5 or 85:10:5. The carbon/nitrogen (C/N) ratio assumed to be appropriate for the cultivation of S. latifolia was 184-223. Pinheading would be difficult below a C/N substrate ratio of 105. Thus, the C/N ratio of the media, as well as the pH, would be vital factors affecting pinheading during S. latifolia cultivation.

Heat transfer of green timber wall panels (그린팀버월 패널의 열전달 특성)

  • Kim, Yun-Hui;Jang, Sang-Sik;Shin, Il-Joong
    • Korean Journal of Agricultural Science
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    • v.38 no.1
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    • pp.115-120
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    • 2011
  • 20% of total energy use to sustain temperature of building inside. In this reasons, researchers effort to improve the thermal insulation capacity with new wall system. Using appropriate materials and consisting new wall system should considered in energy saving design. OSB(Oriented strand board), Larch lining board used to consist wall system. $2{\sim}6$ Larch lining board has tongue & groove shape for preventing moisture. Comparing with gypsum board and green timber lining board as interior sheathing material, temperature difference of Green timber wall system was bigger than temperature difference of gypsum board wall system. This aspects indicate that Green timber wall system was revealed higher thermal insulation property than gypsum board wall system. Gypsum board portion transfer heat easily because temperature difference gradient of gypsum board wall system was smaller than OSB wall system. Total temperature variation shape of G-4-S and G-6-S show similar model but, temperature variation shape in green timber wall portion assume a new aspect. The purpose of this study was that possibility of thermal insulation variation and new composition of wall system identify to improve thermal insulation performance. In the temperature case, this study shows possibility of improving thermal insulation performance. Humidity, sunshine and wind etc. should considered to determine building adiabatic properties.

Re-induction of Embryogenic Tissue from the Cryopreserved Somatic Embryo in Japanese Larch (Larix leptolepis Gordon)

  • Kim, Y.W.;Moon, H.K.
    • Journal of Korean Society of Forest Science
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    • v.97 no.5
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    • pp.547-551
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    • 2008
  • The study aimed to develop a cryopreservation method for long-term storage using mature somatic embryo of Japanese larch. In this study, desiccation treatments significantly affected re-induction rates of embryogenic tissue (ET) from dried somatic embryos. In the effect of different dehydration temperature and duration on the re-initiation ET. the highest frequency was shown when somatic embryos were dehydrated at $25^{\circ}C$ for 2 (45.5%) or 1 day (43.3%), respectively. In addition, low temperatures [$4^{\circ}C$, 2 days (44.2%) or 3 days (43.5%)] were marked higher ET initiation. After that, the initiation value was declined with dehydration duration. For comparison of different relative humidity on re-induction frequency of ET, the best re-induction (43.5%) was obtained from somatic embryos pre-dried at $(NH_4)_2SO_4$ (RH 79%). Both $Na_2HPO_4$ (RH 97%) and $Na_2CO_3$ (RH 88%) treatments were showed the similar rate, 34.6, 34.2%, respectively. However the lowest rate (19.6%) was observed in distilled water (RH 100%). In comparison of the various storage temperatures and duration of the dried somatic embryos, the highest frequency (66.9%) of re-initiation was obtained when somatic embryos were cryopreserved for one day. However, the frequency was gradually decreased as the time length of storage increased regardless of types of storage. None of ET re-initiated when stored at $4^{\circ}C$ for 1, 2 and 84 days.