• 한국산림과학회지
• /
• 제86권4호
• /
• pp.407-414
• /
• 1997

외래 저항성 유전자, Proteinase inhibitor II가 형질전환된 3계통의 벨기에 포플러를 대상으로 딱정벌레에 대한 유전자 발현정도가 기내에서 조사되었다. 포플러 계통은 선발 유전자로서 Nos-promoter와 Neomycin phosphotransferase gene에 의하여 조절되고 곤충에 대한 저항성 유전자로서 CaMV-35S와 Pin2(Proteinase inhibitor II)에 의한 형질전환체이다. 특히, 형질전환된 포플러의 내충성 저항력을 조기검정하기 위하여, 조직배양을 응용한 새로운 방법으로서 곤충의 알을 표면 살균하여 기내의 조직배양묘와 배양하는 동시배양 방법이 이용되었다. 형질전환된 포플러의 저항성은 기내에서 유충에 의해 섭취된 잎면적, 잎 섭취에 의한 유충의 무게 증감, 유충의 성장단계 등에 의하여 조사되었다. 특히, 잎면적은 각각의 LPI(Leaf plastochron index)별로 측정되었고, 잎면적, 유충의 무게, 곤충의 성장 속도는 형질전환체와 비형질전환체 간에 큰 차이를 보였다. 기내에서 무병상태로 배양된 알들이 부화된 후, 유충의 잎 섭취도는 LPI 4와 5사이에서 가장 높았다. 본 실험의 기내 배양법은 외래유전자를 삽입한 이후에 곧바로 발현을 빠른 시간내에 조기검정 할 수 있는 새로운 방법의 개발이라 할 수 있다.

• 임산에너지
• /
• 제22권2호
• /
• pp.54-59
• /
• 2003

최근 들어 북미와 유럽에서는 고밀화한 목질펠릿연료가 재생가능하며 카본뉴트럴한 바이오매스 에너지로서 널리 사용되고 있다. 본 연구에서는 현사시 톱밥의 고밀화를 통한 고형연료화에 관하여 연구하였다. 현사시 품종의 연료적 가치를 평가하기 위하여 열량 및 원소 분석을 수행하였다. 고밀화를 위하여 열압공정을 채택하였으며, 압밀화는 100∼180℃, 250∼1000 kgf/㎠, 2.5∼10분의 조건으로 행하였다. 고밀화연료의 특성은 밀도와 미세분 발생량으로 평가하였다. 목표치로서 고밀화연료의 전건밀도는 1.2 g/㎠ 이상, 5분간 진탕 후의 미세분 발생량은 0.5% 이하로 설정하였다. 목표 밀도와 목표미세분을 만족하기 위해서는 160℃ 이상의 압체온도가 요구되었다. 이 때의 압체압력은 750 kgf/㎠ 이상이 효과적이었다 180℃에서 1000 kgf/㎠으로 5분 이상의 압체가 고밀화연료 제조에 가장 적절한 조건으로 밝혀졌다.

• 한국산림과학회지
• /
• 제99권5호
• /
• pp.706-710
• /
• 2010

Understanding of chemical composition and energy contents in tree is important to develope strategies of renewable energy policy to cope with climate change. Residual biomass as renewable energy source was evaluated and focused on the bark-containing branches. Chemical analysis studies were conducted for different part of yellow poplar (Liriodendron tulipifera), which were partitioned to inner bark, outer bark, small branches, medium branches, big branches and trunk. The variations in hydrophobic extractives, hydrophilic extractives, lignin, carbohydrate compositions, energy contents (higher heating value) and the ash content were determined. The inner and outer bark had higher ash content, hydrophobic and hydrophilic extractives content, and higher energy content than those of tree trunk. Polysaccharides content in inner and outer bark was quite lower than those of stem or branches. Based on the energy content of residual biomass, replacement of fossil fuel and greenhouse gas emission abatement were calculated.

• Journal of the Korean Wood Science and Technology
• /
• 제14권2호
• /
• pp.36-42
• /
• 1986

Both the control and heated specimen of oak, hornbean, alder, poplar, red pine and pitch pine among domestic commercial species and taun imported were used for radial and tangential shrinkage and movement that occurred on changing the relative humidity of the atmosphere from 90 percent to 60 percent at $25^{\circ}C$. The results of this study were as follows. 1. The radial and tangential shrinkage of the control and heated hornbean and oak wood, except alder, of high specific gravity showed greater than species with low specific gravity. The ratio of tangential to radial shrinkage was 1.46 for taun to 2.70 for alder. Green volume specific gravity of the heated and soaked specimen of all species except poplar decreased 1.5 to 3.1 percent. Shrinkage of the heated specimen increased more than that of the control specimen, and antishrink efficiency of all timbers except alder had negative value. Shrinkage from green to air dry of treated specimens increased more than case of total shrinkage, and radial shrinkage of those specimen increased greater than tangential shrinkage. 3. The movement of the heating specimen for 120 hours decreased than those of the control and the heating specimen for 240 hours. The movement of heating oak, poplar, red pine and pitch pine (or 240 hours increased rather than those of the control specimen.

• Journal of Plant Biology
• /
• 제38권2호
• /
• pp.143-151
• /
• 1995

Addition of plant growth hormones [0.01 mg/L NAA and 0.2mg/L benzyladenine (BA)] to a woody plant medium stimulated the adventitious bud formation of poplar explants during culture. Endogenous IAA content increased rapidly at the initial culture stage and then decreased, being followed by rapid increment again at the late culture. But the content of trans-zeatin riboside (t-ZR) increased continuously during the culture. Cytoplasmic soluble proteins were analyzed by one- and two-dimensional SDS-PAGE. Increased amount of 40 kD band was detected by one-dimensional electrophoresis using Coomassie Blue staining during the culture and two distinctive proteins whose mol wt is 40,000 were detected by two-dimensional electrophoresis using autoradiography and these proteins were synthesized continuously prior to the adventitious bud formation. When the midvein segments were transferred to the actinomycin D-containing medium, the spots of adventitious bud-related proteins(ABRPs) did not disappeared but weakened in intensity. So, it is concluded that genes coding for the ABRPs are regulated to some degree at the transcriptional level. Also, they were not observed in BA-free medium, suggesting that these proteins be regulated by cytokinin, which made then possible to form the adventitious bud.

• Journal of the Korean Wood Science and Technology
• /
• 제33권5호통권133호
• /
• pp.66-75
• /
• 2005

Soybean-based adhesives have recently been reconsidered as alternatives to petroleum-based adhesives due to the uncertainty of availability of petrochemical products and the increased demand for wood adhesives. This study was conducted to investigate the adhesive properties of alkaline phenolic soy (APS) resin for hybrid poplar flakeboard. The APS resin was formulated by crosslinking an alkaline soy flour hydrolyzate with lab-prepared PF resin in the soy hydrolyzate to PF resin weight ratios of 70/30, 60/40, and 50/50. The APS resins were used to fabricate homogeneous hybrid poplar flakeboards with different resin solid levels (5%, 7%, and 9%), press temperatures (175 and $200^{\circ}C$), and press times of 8 and 10 minutes. The IB, wet MOR, and dimensional stability properties of board improved with increasing press time, press temperature, and PF level in APS resins. Increasing press time can be used to offset poor IB strength associated with a 9% resin solid level and the excessive moisture content in the mat. The following conditions were concluded to meet the requirements of the CSA standard for exterior-grade flakeboard: a 50% PF level, a 5% resin content, a $200^{\circ}C$ press temperature, and an 8 minute press time.

• 한국세라믹학회지
• /
• 제47권4호
• /
• pp.308-311
• /
• 2010

Porous SiC samples were prepared with three types of wood (poplar, pine, big cone pine) by simply embedding the wood charcoal in a powder mixture of Si and $SiO_2$ at 1600 and $1700^{\circ}C$. The basic engineering properties such as density, porosity, pore size and distribution, and strength were characterized. The samples showed full conversion to mostly $\beta$-SiC with good retention of the cellular structure of the original wood. More rigid SiC struts were developed for $1700^{\circ}C$. They showed similar bulk density ($0.5{\sim}0.6\;g/cm^3$) and porosity (81~84%) irrespective of the type of wood. The poplar sample showed three pore sizes (1, 8, $60\;{\mu}m$) with a main size of $60\;{\mu}m$. The pine sample showed a single pore size ($20\;{\mu}m$). The big cone pine sample showed two pore sizes (10, $80\;{\mu}m$) with a main size of $10\;{\mu}m$. The bend strength was 2.5 MPa for poplar, 5.7 MPa for pine, 2.8 MPa for big cone pine, indicating higher strength with pine.

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
• /
• pp.257-263
• /
• 2006

This paper examines the physico-chemical properties and structural features of thio lignin and alcohol lignin preparations extracted from fast-growing poplar wood. The lignin preparations were characterized using UV, IR and alkaline nitrobenzene oxidation methods. The yield was higher in thiolignin due to its preparation from wood under drastic alkaline conditions and almost the total amount of alkaline degraded lignin was precipitated except acid soluble lignin. In case of ethanol lignin, structural modifications were comparatively less and form a cream colored lignin more or less similar to its original natural color. The methoxyl values were higher due to syringyl unit present in hard wood lignin in addition to guaicyl unit present in soft wood. The higher values of methoxyl content of isolated lignin revealed that it was built up of high syringyl units. The elementary analysis, methoxyl group and hydroxyl groups were presented by $C_{9}$ formula indicated that it was made up of phenyl propane monomers. Nitrobenzene oxidation of thio lignin and ethanol lignin yield more or less the chromatograms of similar pattern, except difference in relative percentage. The ultra violet spectra of lignins were quite similar, irrespective of the source and method of isolation. Infrared spectroscopy studies of poplar deltoides, thio and ethanol lignin shown different absorption bands which have been utilized for structural investigations.

• 한국농림기상학회지
• /
• 제13권4호
• /
• pp.171-175
• /
• 2011

본 연구는 국내에 있는 자생포플러, 도입포플러, 교잡종포플러 15개 클론 삽목묘의 잎녹병에 대한 감수성을 규명하고 저항성 클론을 선발하기 위해 수행되었다. 각 개체별 잎녹병 피해도는 감염된 잎을 경, 중, 심으로 구분하여 일정한 점수를 부여한 후 한 나무당 감염된 잎의 비율로서 추정하였다. 실험에 포함된 15개 포플러 클론들 중 Dorskamp, 봉화 1, 현사시 3이 한국에서 만연하고 있는 Melampsora 잎녹병균에 저항성이 높은 클론으로 선발되었는데 이들 중 봉화 1과 현사시 3은 포플러 6개 절(section)중 Leuce 절에 속하고Dorskamp는 Aigeiros 절에 속한다. 특히 Dorskamp는 외관상으로도 잎녹병에 감염된 잎이 현저히 적어 포플러잎녹병 저항성 품종으로 추천할 만한 클론인 것으로 확인되었다.

• Journal of the Korean Wood Science and Technology
• /
• 제43권2호
• /
• pp.258-264
• /
• 2015

To evaluate the influence of 3A zeolite on the flame retardant properties of poplar plywood. Ammonium polyphosphate (APP) and 3A zeolite were used as flame retardants to prepare plywood samples. The combustion properties, such as heat release rate (HRR), total heat release (THR), mean CO and $CO_2$ yield, smoke production rate (SPR), and total smoke production (TSP), were characterized by a cone calorimeter. A synergistic effect was observed between 3A zeolite and APP on reducing the HRR and mean CO yield. The probable flame retardation mechanism was proposed.