• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.3
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• pp.22-27
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• 2010

Pulping properties of the imported mixed eucalyptus chips and the domestic yellow poplar chips were investigated for comparing two chips as the raw materials for the hardwood chemical pulp. Soda-AQ (anthraquinone) pulping was applied for this study. The pulp from yellow poplar showed higher pulp yield than pulp from mixed eucalyptus, which comes from the lower hot-water soluble extractives and the higher polysaccharides in yellow poplar chips than those of the mixed eucalyptus chips. The yellow poplar pulp had higher average fiber length and fiber width than those of the mixed eucalyptus pulp, which led to the better respond to beating and the higher tear strength than those of the pulp from the mixed eucalyptus chips.

• Journal of Korean Society of Forest Science
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• v.105 no.4
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• pp.463-471
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• 2016

The purpose of this study was to develop allometric equations for identifying the amount of wood and building biomass statistics of L. tulipifera by density, biomass expansion factors and root ratio. For this purpose, total of 40 trees were sampled, which were used consideration the area and the DBH class. As a results, the wood density was $0.43g{\cdot}cm^{-3}$, biomass expansion factors were 1.2, root ratio was 0.2 and uncertainty were 3.9%, 4.6%, 24.1%, respectively. Allometric equations for above ground of L. tulipifera trees were $W=0.060D^{2.524}$. Total and underground allometric equations were $W=0.063D^{2.578}$, $W=0.010D^{2.591}$, respectively.

• The Korea Journal of Herbology
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• v.30 no.4
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• pp.1-9
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• 2015

Objectives : The present study was under taken to characterize chemical composition, antioxidant and cyto-protecting capacity of essential oil obtained from leaves of Liriodendron tulipifera L. Methods : Essential oil from the leafof L. tulipifera L. (EOLL) was extracted by hydro-distillation process and further its chemical composition was evaluated by GC-MS analysis. The in vitro antioxidant potential of the EOLL was determined by DPPH ^●, ABTS ^●+, superoxide and nitric oxide free radical scavenging activity using different concentrations in the range of 50-800 μg/mL. In addition, cyto-protecting property of the EOLLwas determined by MTT assay on Raw 264.7 macrophage cells challenged with hydrogen peroxide (H ₂ O ₂ ). Results : The result of GC-MS analysis showed presence of 34 volatile compounds, principally germacrene D, spathulenol, and α -cadinol in EOLL. The in vitro antioxidant assays of EOLL at the highest used concentration of 800 μg/mL showed 81.62, 84.29, 83.59 and 58.59% inhibition of DPPH ^●, ABTS ^●+, superoxide, and nitric oxide radicals, respectively. It also showed ferric reducing ability with 1310.04 mM Fe (II)/g of essential oil. The EOLL at three different concentrations (200, 400 and 800 μg/mL) protected the cells from H ₂ O ₂ -induced cell damage through scavenging intracellular ROS. Conclusion : The findings from the study suggest that essential oil isolated from leaves of L tulipifera L. is a potent sources of natural antioxidants, which could be used to treat the diseases associated with oxidative stress condition.

• Journal of the Korean Wood Science and Technology
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• v.39 no.1
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• pp.75-85
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• 2011

The main purpose of this study is to evaluate the potential of producing bioethanol from yellow poplar ($Liriodendron$ $tulipifera$) wood chips by oxalic acid pretreatment and to examine the pretreatment conditions by response surface methodology (RSM). Based on $2^3$ factorial design, adjusted variables were reaction temperature ($^{\circ}C$), residence time (min), and acid loading (g/g), and a series of distinct 15 experimental conditions was organized with duplication at central point (total 16 performances). After pretreatment, simultaneous saccharification and fermentation (SSF) was subjected on solid fraction with yeast strain $Pichia$ $stipitis$. Maximum ethanol yields of the most samples were measured at 72 hours and applied to RSM as a dependent variable. 9.7 g/${\ell}$ of ethanol was produced from the solid pretreated at $180^{\circ}C$ for 40 min with 0.013 g/g of oxalic acid loading. According to the response surface methodology, it was determined that the temperature is the most governing factor via statistic analysis.

• Journal of the Korean Wood Science and Technology
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• v.38 no.2
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• pp.149-158
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• 2010

Organosolv pretreatments which utilized sulfuric acid, sodium hydroxide and ammonia as catalysts were conducted to screen the effective catalyst for organosolv pretreatment of Liriodendron tulipifera. The enzymatic hydrolysis was achieved effectively with sulfuric acid (74.2%) and sodium hydroxide (63.7%). They were thus considered as effective catalysts for organosolv pretreatment of L. tulipifera. The organosolv pretreatments with sulfuric acid and sodium hydroxide showed a different behavior on the reaction mechanism. The pretreatment with sulfuric acid increased the biomass roughness and pore numbers. On the other hand, the pretreatment with sodium hydroxide enhanced the surface area due to the size reduction and minor defiberization which were caused by hemicellulose degradation at an initial stage and more defiberization by lignin degradation at a later stage. The organosolv pretreatment with sodium hydroxide was performed at several different conditions to evaluate effectiveness of sodium hydroxide as a catalyst for organosolv pretreatment. According to the results of enzymatic digestibility, the changes of chemical composition and the morphological analysis of pretreated biomass, it was suggested that the pretreatment time impacted primarily on enzymatic hydrolysis. Increase in surface area during the pretreatment was a major cause for improvement in enzymatic digestibility when sodium hydroxide was used as a catalyst.

• Journal of the Korean Wood Science and Technology
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• v.39 no.2
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• pp.187-195
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• 2011

In this study, dilute acid pretreatment of $Liriodendron$ $tulipifera$ was performed for enzymatic hydrolysis. As the pretreatment temperature was increased, enzymatic hydrolysis and enzyme adsorption yield also increased. The highest enzymatic hydrolysis yield was 57% (g/g) and enzyme adsorption was 44% (g/g). Enzymatic hydrolysis yield was determined with weight loss of pretreated biomass by enzyme, and enzyme adsorption was a percentage of enzyme weight attaching on pretreated biomass compared with input enzyme weight. When $L.$ $tulipifera$ was pretreated with 1% sulfuric acid at $160^{\circ}C$ for 5 min., hemicellulose was significantly removed in pretreatment, but the lignin contents were constant. Other changes in surface morphology were detected on biomass pretreated at $160^{\circ}C$ by a field emission scanning electron microscope (FESEM). A large number of spherical shapes known as lignin droplets were observed over the entire biomass surface after pretreatment. Hemicellulose removal and morphological changes improved enzyme accessibility to cellulose by increasing cellulose exposure to enzyme. It is thus evidence that enzyme adsorption is a significant factor to understand pretreatment effectiveness.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.110-118
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• 2016

We compared germination efficiency for somatic embryos (SE) of Liriodendron tulipifera using semi-solid (SS), temporary immersion bioreactors (TIB), and continuous immersion bioreactors (CIB) to produce vigorous plants. The bioreactors were designed to be immersed in liquid media with plantlets with an adjustable immersion time. TIB and CIB improved germination rates up to 80.86% and 95.21%, respectively, however, CIB produced more hyperhydric plantlets than TIB. The height of plantlets in TIB was significantly higher than for those in CIB. Fresh weights of plantlets grown in CIB of were significantly lower than for those grown in TIB. The lowest chlorophyll concentration was found in in vitro plantlets from CIB. We examined abnormally developed leaves, stems, and apical zones of in vitro plantlets that were produced in CIB. Among the three types, SS showed the highest stomatal density and the shortest stomatal length in in vitro plantlets. After acclimatization, plants from CIB exhibited the lowest values in biomass, such as height, root collar diameter, leaf fresh weight, leaf length, leaf width, petiole length, petiole diameter, and leaf area. Photosynthesis and transpiration rates of ex vitro plants were not significantly different among the three culture types, but stomatal conductance was higher in TIB than in the SS and CIB. Therefore, the results suggest that TIB is the preferable bioreactor to improve in vitro plantlet regeneration of L. tulipifera. TIB-originated plants showed higher growth rate than SS and CIB after transferring to soil.

• Landscaping Tree
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• s.129
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• pp.14-19
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• 2012

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.4
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• pp.16-20
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• 2013

Yellow poplar grown in Korea and imported eucalyptus were compared their kraft pulping characteristics and evaluated the replacing possibility of eucalyptus by yellow poplar. Difference between yellow poplar and eucalyptus were investigated in chemical composition and fiber morphology. Yellow poplar kraft pulp resulted in the higher yield, longer fiber length and thicker fiber, and higher pulp strength than that of eucalyptus. More xylan survived in eucalyptus than yellow poplar during kraft pulping, which led to similar pulp yield even though polysaccharides in Eucalyptus was 4.5% less than in yellow poplar. Longer and thicker yellow poplar pulp fiber resulted in better beating response and pulp strength properties.

• Journal of Forest and Environmental Science
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• v.27 no.2
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• pp.119-125
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• 2011

Heating value is the one of most important factor in energy use of the woods. This study was investigated for determining the heating value according to the moisture content level(%) of major broad-leaved tree in Korea. Heating value was decreased rapidly regardless the kinds of species (Liriodendron tulipifera, Alnus japonica, and Quercus mongolica) and parts of woods (wood part, and bark) as the moisture content (MC) was increased. In addition, bark had higher heating value than wood part. Liriodendron tulipifera showed the highest heating value among the other two species.