미생물 펄프화시 trembling aspen의 화학적 성분 변화

안세희 대구대학교 생명과학연구소 2004 생명과학연구 Vol.3 No.1

Trembling aspen wood (Populus tremuloides) was treated with white rot fungi Ceriporiopsis subvermispora for 1, 2, 4 and 6 weeks. On a laboratory scale, steaming, cooling, and fungal inoculation were performed in a batchwise fashion. As fungal decay advanced on, lignin contents were decreased gradually up to 20 % after 6 weeks, whereas MeOH extracts were significantly increased. Alkali solubility of cell wall residues was improved until 4-weeks of fungal treatment, but additional treatment did not give any effects. Milled wood lignins (MWLs) were isolated from the each decayed wood by Bjoerkman procedure and subjected to thioacidolysis and analytical pyrolysis to investigate the modification of lignin structures during fungal incubation. Thioacidolysis revealed that the yields of trithioethylated C6C3 monomers, a parameter for frequency of β-O-4 linkages in lignin, were substantially reduced in purified lignins from each decayed wood as a function of periods of fungal treatment and the reduction of β-O-4 linkages reached 20 % after 6 weeks. 대구대학교 생명과학연구 제3권 제1호 (2004. 07) Furthermore, S/G ratios estimated by thioacidolysis demonstrated that syringyl-type lignin was much favorably degraded than guaiacyl-type lignin by C. subvermispora.

백색부후균인 Phanerochaete chrysosporium에 의한 리그닌 모델 화합물 분해

안세희,島田幹夫 대구대학교 과학기술연구소 1999 科學技術硏究 Vol.5 No.5

The degradation products were extracted with ethyl acetate and identified by NMR and GC-MS to elucidate degradation pathways of the lignin substructure model compounds. All degradation products were identified by GC-MS in comparison with mass spectra of synthetic authentic compounds. The results are classified to the cleavage of side chain and aromatic ring opening of the compounds. We found that lignin peroxidase of P. chrysosporium also catalyzes one electron oxidation of non-phenolic compounds in the initial degradation of lignin substructure model compounds. Lignin peroxidase catalyzes one electron oxidation of aromatic rings of non-phenolic aromatic compounds to give unstable cation radical which undergo spontaneous transformation. The Cα-Cβ 13 bond of the propyl side chain is homolytically cleaved via an aryl cation radical of the substrate to give benzyl cation, and guaiacoxyethyl radical which is attacked by dioxygen to form an unstable hemiketal. The O-Cβ bond of hemiketal is subsequently cleaved to give vanillin and benzaldehyde. The aromatic ring opening products were also identified as lignin peroxidase degradation products of β-O-4 model compound.

Packed-bed column에서 산림부식질의 중금속 흡착 특성

안세희,손성길,이동화,최인규 대구대학교 과학기술연구소 1999 科學技術硏究 Vol.5 No.5

This experiment investigates the adsorption characteristic of heavy metals by humic substances of Forest soil in a packed bed column. Forest humic substances contain various components such as carboxyl group, phenol group which provide active sites for heavy metal binding. Humic substances of high cation exchange capacity have been utilized for removing metal ions. The analysis of chemical structure of humic substances was investigaed by FT-IR and CP/MAS Carbon-13 NMR Spectrometer at last year. Adsorption experiments of heavy metal cation by humic substances was conducted to the optimum adsorption condition. The adsorption isotherms for Cu, Zn, Cd, Cr conformed to Langmuir's equation. In the packed bed column, the adsorption ratios of Cu, Zn, Cd, Cr on the humic substances were more than 90%. There were no significant differences between the adsorption ratio and the species of humic substances. With increasing retention time, the removal efficiency of heavy metal ions were not changed greatly. The adsorption ratio of the heavy metal ions were considerably greater for the packed bed reactor than for the stirred reactor. The stirred and column methods give similar result for the adsorption characteristics of heavy metal ion in humic substances.

Stirred Reactor에서 산림부식질의 중금속 흡착 특성

안세희,정연봉,이동화,최인규 대구대학교 과학기술연구소 1999 科學技術硏究 Vol.5 No.5

Forest humic substances are inexpensive and available in a great quantity. They contain various components such as carboxyl group, phenol group which would provide active sites for heavy metal binding. In actual operation process, a continuous adsorption on a packed bed reactor is more economically. Humic substances of high cation exchange capacity have been utilized for removing metal ions. Humic substance have drawn considerable attention from those who are ingaged in environmental studies. Adsorption experiments of heavy metal cations by humic substance was conducted to obtain the optimum adsorption condition. In the stirred reactor, the adsorption ratio of Cu, Zn, Cd on the humic substances were more than 90% but those of Cr were less than 40%. The humic substances considerably varied in the adsorption ability to heavy metal ions in the stirred reactor. The humic substances from subtropical temperate deciduous forest showed highest removal efficiency to Cu among various humic substances. There were no significant differences between the adsorption ratio and reaction temperature ranging 20 to 50. As the concentration of heavy metal ions increased, the adsorption ratio of heavy metal was decreased. The adsorption of Cu occurred rapidly in the incipient stage.

Adsorption Characteristics of Heavy Metals by Various Forest Humic Substances

Ahn, Sye-Hee,Koo, Bon-Wook,Choi, In-Gyu 한국목재공학회 2003 목재공학 Vol.31 No.6

Various forest humic substances were collected at different climate regions with different forest types, and adsorption of heavy metals such as Cu(Ⅱ), Zn(Ⅱ), Cd(1I) and Cr(Ⅲ) were characteristically conducted to obtain optimal adsorption conditions and to evaluate the removal efficiency of heavy metals by each forest humic substance. The adsorption isotherms for Cu(Ⅱ), Zn(Ⅱ), Cd(Ⅱ) and Cr(Ⅲ) conformed to Langmuir's equation. In the stirred reactor, the removal efficiencies of Cu(Ⅱ), Zn(Ⅱ) and Cd(Ⅱ) by forest humic substances were more than 90% but that of Cr(Ⅲ) was less than 60%. The adsorption capacities of heavy metals in the stirred reactor were considerably varied depending on the type of forest humic substances. Among humic substances, the one from deciduous forest at subtropical region showed the highest removal efficiency for Cu(Ⅱ). There was no significant difference in removal efficiency by each heavy metal depending on reaction temperature ranged from 20 to 50 C except for Cr(Ⅲ), and the adsorptions of Cu(Ⅱ), Zn(Ⅱ) and Cd(Ⅱ) were occurred rapidly in the incipient stage within 10 min, while Cr(Ⅲ) needed more reaction time to be adsorbed. The stirred and packed bed column reactors showed similar adsorption characteristics of heavy metals by humic substances, but the removal efficiency was considerably higher in the packed bed column' reactor than in the stirred reactor. Therefore, in actual operation process, a continuous packed bed column reactor was more economical.

소나무재선충 감염 소나무의 목재해부학적 특성

안세희 ( Sye Hee Ahn ),전문장 ( Mun Jang Jeon ),엄영근 ( Young Geun Eom ),오세창 ( Sei Chang Oh ),이미림 ( Mi Rim Lee ) 한국목재공학회 2011 목재공학 Vol.39 No.1

소나무재선충병은 우리나라의 대표 수종인 소나무를 괴사시키는 주요 산림병의 하나로 재선충의 침입과 수체내에서의 이동 경로 파악은 이들의 서식 형태를 구명하는데 매우 중요하다. 따라서 본 연구에서는 감염목 내에서의 재선충 주요 서식 부위와 이동 경로를 명확히 구명하기 위해 재선충 피해목에 대한 현미경적 조사를 수행 하였다. 그 결과 피해목의 특징으로는 횡단면, 방사단면, 접선단면 모두에서 주로 방사조직이 감염을 통에 진하게 착색된 것으로 드러났으며 수지구에서도 집중적인 피해가 관찰되었다. 또한 형성층과 가까운 변재 부위에서는 연륜을 따라 접선방향으로 연속 배열된 상해수지구로 보이는 특징이 관찰되었다. 재선충은 방사가도관보다는 방사유세포에서 그리고 수평수지구를 지니지 않는 단열방사조직보다는 수평수지구를 지니는 방추형방사조직에서 훨씬 더 많은 재선충이 발견되었으며 방사조직에서 가도관으로 이동하는 선층도 관찰되었다. 방사조직에서 가도관으로의 이동 시 가도관의 벽을 천공한 다음 이동하거나 크기가 작은 개구부인 측벽의 유연벽공을 통해 이동하기보다는 크기가 큰 개구부인 창상 직교분야벽공을 이동 통로로 삼는 것으로 사료되었다. The pine wilt disease is one of the most serious forest diseases that kill the pine trees, and the study on the invasion and movement of the pine wood nematode within the tree is very important for understanding the inhabitation of pine wood nematode. In this relation, the microscopic observation was carried out to study the place of inhabitation and movement of pine wood nematode within the infested wood. In result, the rays were mainly infested by pine wood nematode and showed dark discoloration due to their necrosis in cross, radial and tangential surface. Also, the intensive damage was found in the resin canals. On the other hand, some traumatic resin canals in tangential band were identified in the sapwood near the cambium. In the ray, the pine wood nematode occurred more commonly in the ray parenchyma cell and fusiform ray with horizontal resin canal than in the ray tracheid and uniseriate ray without horizontal resin canal, respectively. The pine wood nematode was thought to move from ray to tracheid through the large natural opening, window-like pit, in the cross-field, neither through the small natural opening, bordered pit, in the tracheid nor through the tracheid wall by creating a bore hole.

폼알데하이드 흡착능에 대한 커피부산물의 열처리 조건 영향

안세희 ( Sye Hee Ahn ) 한국목재공학회 2015 목재공학 Vol.43 No.3

본 연구는 커피부산물(이하 CW)의 재자원화 방안으로 여러 조건에서 열처리한 CW를 폼알데하이드(이하 HCHO)와 함께 데시케이터에 방치한 후, CW에 흡착된 HCHO 양을 아세틸아세톤법과 dinitrophenylhydrazine (이하 DNPH)법으로 측정 및 비교하여 섬유판 제조에 있어 흡착제로서 CW의 적용 가능성을 탐색하기 위하여 수행하였다. 데시케이터 내의 증류수에 흡착된 HCHO 양을 아세틸아세톤법으로 측정한 결과 열처리하지 않은 CW에서 가장 낮았고 100℃의 열처리 온도까지 계속 증가하였으나, 100℃ 이상의 온도에서는 차이가 없었다. CW에 직접 흡착된 HCHO양은 100℃에서 열처리한 CW에서 가장 높았으며, 50℃, 150℃, 0℃, 250℃ 그리고 200℃ 순으로 측정되었다. DNPH법으로 측정한 CW의 HCHO 흡착능 결과는 데시케이터 내에 HCHO와 함께 방치시킨 무열처리 CW의 증류수에 교반시킨 용액에서는 HCHO가 검출되지 않은 반면, 열처리 CW 교반액에서는 일정량의 HCHO가 검출되었다. 그검출량은 100℃에서 10분간 열처리시킨 CW에서 가장 높았다. 또한 HCHO가 흡착된 CW 자체의 HCHO 양은 열처리 시간과 상관없이 100℃의 열처리 온도까지 계속 증가하였으나, 그 이상의 열처리 온도에서는 HCHO 검출량의 증가폭이 줄거나 검출량이 감소하는 것으로 나타났다. 결과를 종합하면, 최대 HCHO 흡착을 위한 CW의 열처리 조건으로 기술적 그리고 경제적 측면을 고려하여 100∼150℃의 온도 범위에서 10분으로 판단되며, 이 열처리 CW를 섬유판 제조에 있어 흡착제로 일정량 첨가한다면 기존 섬유판의 HCHO 방산량을 낮출 수 있는 하나의 방안이 될 것으로 생각한다. This study was conducted to examine the potential use of coffee waste (CW) as an adsorbent of HCHO by adding into fiberboard. For the purpose, CW treated with various temperatures and times was placed in desiccator with a HCHO solution and then the HCHO adsorptivity of the CW was measured by acetylacetone (ATAN) and DNPH methods. In the results of ATAN analysis, amount of HCHO adsorbed in distilled water was the lowest on the non-treated CW and steadily increased to 100℃-treated temperature. However, over the 100℃, heating temperature (H-Temp) had not an effect on the HCHO adsorptivity of CW. Amount of HCHO adsorbed on CW itself was the highest at 100℃ H-Temp, following by 50℃, 150℃, 0℃, 250℃ and 200℃. For the HCHO adsorptivity of CW measured by DNPH methods, HCHO was not detected in the distilled water stirred with non-treated CW, but detected from the distilled water stirred with heating-treated CW. The content was the highest in the CW heating-treated at 100℃ for 10 min. In addition, HCHO adsorbed on CW itself increased to the H-Temp of 100℃ regardless of heating time, but decreased or reduced greatly degree of the increase over 100℃ H-Temp. In conclusion, optimal heating conditions of CW for the HCHO adsorption might be H-Temp between 100 and 150℃ with 10 min according as technical and economical reasons. Heating-treated CW manufactured with above the conditions can be used as an adsorbent in conventional fiberboard production for reducing HCHO emssion.

습도반복처리조건하에서의 목질재료의 내구성능평가 ( I ) - 파괴인성치의 산정 -

안세희(Sye Hee Ahn),오세창(Sei Chung Oh) 한국가구학회 1998 한국가구학회지 Vol.9 No.1

Bending test were carried out on nominal 15mm thick commercial Plywood, MDF and Particleboard under alternating humidity conditions (40%-80%) with constant temperature of 20 'C. Specimens were prepared with a set of notched and unnotched conditions and tested using midspan loading. By the test results, retention of flexural strength, MOE and fracture toughness were calculated.<br/> Typical load-deflection curves were different in3 types of tested specimens respectively, and especially linear to fracture in PB. Time to fracture in MDF was longer than Plywood and PB. The retension of flexural strength of un notched specimens varied in each cycle, and MOE was decreased considerably in PB and MDF panels. Stress concentratjon factor and critical stress intensity factor were decreased as the cycles were repeated, especially after 3~4th cycle, The effect of alternating humidity conditions on panel performance was higher in PB panels than in plywood and MDF panels. This study will offer the convenience of comparing the behavior of wood-based panels under cyclic humidity conditions by means of fracture toughness and retention of performance.<br/>

Effect of Different Zeolite Supported Bifunctional Catalysts for Hydrodeoxygenation of Waste Wood Bio-oil

( Shinyoung Oh ),( Sye-Hee Ahn ),( Joon Weon Choi ) 한국목재공학회 2019 목재공학 Vol.47 No.3

Effects of various types of zeolite on the catalytic performance of hydrodeoxygenation (HDO) of bio-oil obtained from waste larch wood pyrolysis were investigated herein. Bifunctional catalysts were prepared via wet impregnation. The catalysts were characterized through XRD, BET, and SEM. Experimental results demonstrated that HDO enhanced the fuel properties of waste wood bio-oil, such as higher heating values (HHV) (20.4-28.3 MJ/kg) than bio-oil (13.7 MJ/kg). Water content (from 19.3 in bio-oil to 3.1-16.6 wt% in heavy oils), the total acid number (from 150 in bio-oil to 28-77 mg KOH/g oil in heavy oils), and viscosity (from 103 in bio-oil to 40-69 mm²/s in heavy oils) also improved post HDO. In our experiments, depending on the zeolite support, NiFe/HBeta exhibited a high Si/Al ratio of 38 with a high specific surface area (545.1 m²/g), and, based on the yield of heavy oil (18.3-18.9 wt%) and HHV (22.4-25.2 MJ/kg), its performance was not significantly affected by temperature and solvent concentration variations. In contrast, NiFe/zeolite Y, which had a low Si/Al ratio of 5.2, exhibited the highest improved quality for heavy oil at high temperature, with an HHV of 28.3 MJ/kg at 350 °C with 25 wt% of solvent.

Preliminary Study of Rapeseed Flour-based Wood Adhesives for Making Wood Flooring

In Yang,Sye Hee Ahn,In Gyu Choi,Gyu Seong Han,Sei Chang Oh 한국목재공학회 2011 목재공학 Vol.39 No.5

Adhesives derived from renewable resources allow wood panel producers to make lower cost alternatives to formaldehyde-based adhesive resins. Among them, adhesive components extracted from industrial by-products or wastes are the most important research fields in the efficient utilization of waste and cost reduction. In our study, the rapeseed flour, which is a by product from the production of biodiesel extracted from rapeseed, was introduced to develop alternative adhesives for the production of wood flooring. The rapeseed flour was hydrolyzed with 1% sodium hydroxide solution and PF prepolymers were prepared with 3-molar ratios, 1.8, 2.1 and 2.4. The linear fracture mechanics was introduced to evaluate the glue bond quality in wood flooring composed of fancy-veneered and plywood, and the formaldehyde emission and adhesive penetration were also investigated. The formaldehyde emissions of wood flooring met the requirement of the standard of SE0 specified in the KS standard. The rapeseed flour adhesive penetrated sufficiently into the vessel elements and lumens in fancy veneer and plywood and gave strong bond quality to the wood flooring. The fracture mechanics was introduced to evaluate the adhesive joint between fancy veneer and plywood. The critical stress intensity factor (K(ic)) of boliva overlayed wood flooring was increased with increasing molar ratio and this was the same tendency in oak overlayed wood flooring. From the results, the formulated adhesives were efficiently used to bond fancy veneer onto the plywood to make wood flooring and showed a potential to be used as a component of environmentally friendly adhesive resin systems for production of flooring.