• Journal of Adhesion and Interface
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• v.11 no.2
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• pp.41-49
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• 2010

Furan-containing epoxide monomers (8, 9) were designed and synthesized as carbon-neutral, environment-friendly adhesion material. Bicyclic skeleton were constructed using the Diels-Alder reaction of furan and methyl acrylate, both readily accessible starting material from a biomass via bio-refinery process. After reduction of ester functionality, resulting hydroxyl moieties were coupled to epichlorohydrin to provide the epoxy-functionalized furanic monomers (8, 9). The structure of new furanic monomers was confirmed by $^1H$ and $^{13}C$ NMR spectroscopy. As UV-curable monomers, basic properties such as UV curing time and the extent of UV curing were evaluated by photo DSC. Photo-curing shrinkages were measured by linear variable differential transformer transducer (LVDT) and the effect of molecular structure on shrinkage was considered. In addition, new synthetic compounds showed the shear strength over 3 MPa when they were photo-cured between polycarbonate plates, which indicates these compounds are feasible to use as photo-curable adhesive materials.

• Clean Technology
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• v.24 no.1
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• pp.70-76
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• 2018

Pyrolysis of Saccharina japonica in an Auger reactor was conducted by varying the temperature and the auger speed and then physicochemical properties of the S. japonica-derived pyrolysis oil were analyzed. The maximum yield of S. japonica-derived pyrolysis oil (32 wt%) was obtained at a pyrolysis temperature of $412^{\circ}C$ and an auger speed of 20 rpm. Due to low carbon content and high oxygen content in the pyrolysis oil, the higher heating value of S. japonica-derived pyrolysis oil was $23.6MJ\;kg^{-1}$, which was about 60% that of conventional hydrocarbon fuels. By GC/MS analysis, 1,4-Anhydro-d-galactitol, dianhydromannitol, 1-hydroxy 2-propanone and isosorbide were identified as the main chemical compounds of S. japonica-derived pyrolysis oil. The bio-char has low higher heating value ($13.0MJ\;kg^{-1}$) due to low carbon content and high oxygen content and contains a large amount of inorganic components and sulfur.

• Particle and aerosol research
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• v.10 no.4
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• pp.169-176
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• 2014

Air samples were collected at various altitudes (from 165 to 1153 m) to observe vertical distribution of particulate PAHs concentrations using a very compact and light particle sampling package developed by Eun et al.(2013). TD-GC-MS developed by Hwang et al.(2014) was applied to PAHs analysis for effective analysis of PAHs contained trace amounts in the samples. The ranges of total PAHs concentrations were from 6.95 to $96.0ng\;m^{-3}$ on the ground and from 3.75 to $21.74ng\;m^{-3}$ at high altitude, respectively. All of particulate PAHs concentrations measured on the ground were higher than those measured at high altitude, while, the profile of individual PAH compounds between the ground and high altitude samples were similar. It means the distribution of particulate PAHs concentrations at high altitude were affected by the emission of PAHs emitted from ground.

• KSBB Journal
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• v.19 no.6 s.89
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• pp.484-488
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• 2004

Fermentation studies were conducted in batch and continuous flow cell-recycle reactors with food by-products as substrates. The genus Propionibacterium acidipropionici ATCC 4965 was utilized in the production of organic acids. Good performance was achieved in the batch fermentation using hydrol as a carbon source and corn steep liquor (CSL) as nitrogen and vitamin sources. Product yields and productivity based on maximum values were 0.80 g total acids/g glucose and 0.26 g total acids/L/h, respectively, when $3\%$, (w/v) of hydrol and $2.5\%$, (w/v) of CSL were utilized. Continuous fermentation with cell-recycling system using the optimum amounts of substrates resulted in dramatic increase in cell concentration (X) and maximum productivity (P). Compared to the batch fermentation, X and P were increased by as much as 21 and 13 times, respectively, at the dilution ratio of $0.2\;hr^{-1}$, indicating that cell recycling fermentation of food by-products provides valuable means for the mass production of organic acids as well as utilizing cell mass as good nutrient resources.

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.335-341
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• 2013

Ammonia circulation reactor (ACR) was devised for the effective pretreatment of corn stover. This method is designed to circulate aqueous ammonia continuously so that it can reduce the chemical and water consumption during pretreatment. In this study, ammonia pretreatment with various reaction conditions such as reaction time (4~12 hour), temperature ($60{\sim}80^{\circ}C$), and solid:liquid ratio (1:3~1:8) was tested. Chemical compositions including solid remaining after reaction, lignin and carbohydrates were analyzed and enzymatic digestibility was also measured. It was observed that as reaction conditions become more severe, lignin removal was significantly affected, which was in the range of 47.6~70.6%. On the other hands, glucan and xylan losses were not substantial as compared to that of lignin. At all tested conditions, the glucan loss was not changed substantially, which was between 4.7% and 15.2%, while the xylan loss varied, which was between 7.4% and 25.8%. With (15 FPU-GC220+30 CBU)/g-glucan of enzyme loading, corn stover treated using ammonia circulation reactor for 8~12 hours resulted in 90.1~94.5% of 72-h glucan digestibility, which was higher than 92.7% of $Avicel^{(R)}$-101. In addition, initial hydrolysis rate (at 24 hour) of this treated corn stover was 73.0~79.4%, which was shown to be much faster than 69.5% of $Avicel^{(R)}$-101. As reaction time increased, more lignin removal and it was assumed that the enhanced enzymatic digestibility of treated biomass was attributed to the lignin removal.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.2
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• pp.11-22
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• 2017

To successfully create a low-carbon landscape in order to become a low-carbon city, it is necessary to understand the dynamics of artificial greening's resources on a multi-scale. Additionally, the effects of carbon storage should be quantitatively evaluated. The purpose of this study is to simulate and evaluate the changes in carbon storages of artificial ground trees using system dynamics throughout a long-term period. The process consisted of analyzing the dynamics of the multi-scale carbon cycle by using a casual loop diagram as well as simulating carbon storage changes in the green roof of the Gangnam-gu office building in 2008, 2018, 2028, and 2038. Results of the study are as follows. First, the causal loop diagram representing the relationship between the carbon storage of the artificial ground trees and the urban carbon cycle demonstrates that the carbon storage of the trees possess mutual cross-scale dynamics. Second, the main variables for the simulation model collected 'Biomass,' 'Carbon storage,' 'Dead organic matter,' and 'Carbon absorption,'and validated a high coefficient of determination, the value being ($R^2$=0.725, p<0.05). Third, as a result of the simulation model, we found that the variation in ranking of tree species was changing over time. This study also suggested the specific species of tree-such as Acer palmatum var. amoenum, Pinus densiflora, and Betula platyphylla-are used to improve the carbon storage in the green roof of the Gangnam-gu office building. This study can help contribute to developing quantitative and scientific criteria when designing, managing, and developing programs on low-carbon landscapes.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.158-162
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• 2012

The acclimatization of in vitro propagated plants is an important step to produce vigorous plants for clonal forestry and in vitro micro-environment may affect the growth in ex vitro condition. To monitor in vitro environmental effects on the growth in ex vitro condition, several culture systems such semi-solid medium(SS), temporary immersion bioreactor(TIB) and continuous immersion bioreactor(CIB) culture types were tested to compare for the growth of acclimated plants of Liriodendron tulipifera. Results suggested that morphological characters, stomatal conductance, evapotranspiration and chlorophyll contents of acclimated plants were affected by the different of in vitro culture conditions. CIB type of culture was resulted to the lowest value in the biomass of acclimated plants. Net photosynthsis rate of CIB was the same level as those of SS and TIB. However, stomatal conductance, evapotranspiration and $CO_2$ partial pressure in the intercellular air space were lower than those of SS and TIB. The amounts of chlorophyll a, b and carotenoids were also lower than those of the other two culture systems. TIB, showing a little lower or higher value than SS in many growth character, is recommended rather than CIB to produce healthy yellow poplar plants in ex situ condition.

• Weed & Turfgrass Science
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• v.5 no.3
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• pp.111-125
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• 2016

Cordgrass (Spartina spp.) is recognized as a highly invasive plant in estuaries throughout the world because of remarkable versatility and resiliency, significant reproduction, strong adaptability, rapid spreading, and vigorous growth. In this review, therefore, to provide insights on the effective management practices, the previous research works were summarized and discussed. Spartina spp. is a perennial halophyte, warm-season (C4) grass that reproduces both sexually through seeds and asexually by rhizomes. Management strategies for cordgrass have included various physical, biological, and chemical controls. Herbicides are usually the most cost-effective means of control. Currently, glyphosate, imazapyr, fluazifop and haloxyfop have been practically used. To improve the control efficacy, a combination of two more than methods (example, mowing-spraying) is needed to be applied consistently every year for at least 3 to 4 years and to be sprayed with enough dry time (>4-6 hr) at an early growth stage (before flowering). Consistently repeated application of same herbicide have to be avoided to prevent an unexpected emergence of herbicide-resistant lines. On the other hand, Spartina spp. have many positive functions for agricultural and eco-engineering purposes. Thus, we have to give more intensive research for effectively managing advantages and disadvantages of Spartina plantations.

• Journal of the Korean Wood Science and Technology
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• v.46 no.3
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• pp.231-240
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• 2018

Bamboo is one of the major biomass resources that have many advantages such as fast growing, easy cultivation, short rotation, and a relatively lower price. In this study, the anatomical characteristics of Moso bamboo (Phyllostachys pubescens) by age from one-year-old to five-year-old were examined by optical and scanning electron microscopy. Also, the crystalline properties such as relative crystallinity and crystallite width were investigated by an X-ray diffraction method. In one-year-old bamboo xylem, a few vascular bundles showed missing bundle sheath in near the intercellular space. Moreover, one-year-old bamboo had the shortest fiber length and the smallest values in vessel diameter, width of vascular bundle, and thickness of inner layer. One-year-old bamboo also showed the smallest values in the crystallinity and crystallite width. Near epidermis samples had longer fiber length and greater vascular bundle spacing than near pith samples. Relative crystallinity and crystallite width near the epidermis were also higher than near the pith. This study revealed significant differences in qualitative and quantitative anatomical characteristics between one-year-old and two-year- or more old Moso bamboos. It is concluded that the structural differences by bamboo age can be used to differentiate the characteristics of juvenile and mature bamboo.

• Journal of agriculture & life science
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• v.44 no.3
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• pp.15-21
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• 2010

We estimated the biomass productivity and the storage potential of nitrogen, the major contributor of non-point source pollution, with four three-year-old four poplar clones in a riparian woody buffer established in the Anseong River in Anseong, Korea. Stem of Populus alba ${\times}$ P. glandulosa clone 72-31 and Populus deltoides ${\times}$ P. nigra clone Dorskamp showed the highest percentage of aboveground biomass components, followed by branch and leaf. Nitrogen content in aboveground biomass components of two poplar clones was the highest in leaf and the lowest in stem. Nitrogen content in leaf and branch of clone 72-31 was higher than that of clone Dorskamp, while it in stem was lower. Populus deltoides clone Ay48 showed the highest above-ground biomass productivity, which was estimated as $37.5ton\;ha^{-1}$ at age 3. However, clone 72-31 was the lowest in above-ground biomass productivity. Nitrogen storage potential in aboveground biomass of 3-year-old poplar clones was high in order of aboveground biomass. Clone Ay48 showed the highest nitrogen storage potential in aboveground biomass, which was estimated as $218.3kg\;ha^{-1}$ at age 3.