• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.72-72
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• 2018

The root of Angelica gigas Nakai (AGN) is used as a traditional herbal medicine in Korea for the treatment of many diseases. However, a major challenge associated with the usage of the active compounds from AGN is their poor water solubility. Therefore, this work aimed to enhance the solubility of active compounds by a chemical (viz. surfactant) and physical (hot melt extrusion) crosslinking method (CPC). Infrared Fourier transform spectroscopy (FT-IR) revealed multiple peaks in extrudate solids representing new functional groups including carboxylic acid, alkynes and benzene derivatives. Differential scanning calorimetry (DSC) analysis of the extrudate showed lower glass transition temperature (Tg) and lower enthalpy (${\Delta}H$) (Tg: $43^{\circ}C$; ${\Delta}H$: <6 (J/g)) compared to the non-extrudate (Tg $68.5^{\circ}C$; ${\Delta}H$: 123.2) formulations. X-ray powder diffraction (XRD) analysis revealed amorphization of crystal materials in extrudate solid. In addition, nanonization, enhanced solubility and higher extraction of phenolic compounds were achieved in the extrudate solid. Among the different extrudates, acetic acid- and Span 80-mediated formulations showed superior extractions. We conclude that the CPC method successfully enhanced the production of amorphous nano dispersions from extrudate solid formulations.

• 한국약용작물학회지
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• 제26권4호
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• pp.317-327
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• 2018

Background: The root of Angelica gigas Nakai is used as a traditional herbal medicine in Korea for the treatment of many diseases. However, the poor water solubility of the active components in A. gigas Nakai is a major obstacle to its bioavailability. Methods and Results: This work aimed at enhancing the solubility of the active compounds of A. gigas Nakai by a chemical (using a surfactant) and physical (hot melt extrusion, HME) crosslinking method. Fourier transform infrared spectroscopy revealed multiple peaks in the case of the extrudate solids, attributable to new functional groups including carboxylic acid, alkynes, and benzene derivatives. Differential scanning calorimetry analysis showed that the extrudate soilid had a lower glass transition temperature ($T_g$) and enthalpy (${\Delta}H$) ($T_g:43^{\circ}C$, ${\Delta}H$ : < 6 J/g) as compared to the non-extrudate ($T_g:68.5^{\circ}C$, ${\Delta}H:123.2$) formulations. X-ray powder diffraction analysis revealed the amorphization of crystalline materials in the extrudate solid. In addition, enhanced solubility (53%), nanonization (403 nm), and a higher amount of extracted phenolic compounds were achieved in the extrudate solid than in the non-extrudate (solubility : 36%, nanonization : 1,499 nm) formulation. Among the different extrudates, acetic acid and span 80 mediated formulations showed superior extractions efficiency. Conclusions: HME successfully enhanced the production of amorphous nano dispersions of phenolic compound including decursin from extrudate solid formulations.

• Journal of the Korean Wood Science and Technology
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• 제30권1호
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• pp.1-10
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• 2002

제지 공정중에서 발생하는 슬러지의 효율적인 활용 방안중의 하나로써 목질보드 원료 대체 재료로써의 그 가능성을 평가하기 위하여 제지 슬러지, 합성 섬유, 목섬유의 혼합비를 각각 5:5:90, 15:15:70, 25:25:50으로 PMDI와 요소수지 접착제를 사용하여 목표비중 0.7, 0.8, 0.9인 복합재를 제작하여 물리적 및 기계적 성질을 측정한 결과 제지 슬러지와 합성 섬유를 30%~50%를 혼합하여 복합재를 제조하여도 기존의 보드와 비교하여 손색이 없는 제품을 생산할 수 있다고 판단되었다.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1348-1356
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• 2017

Integration of wind generators with the conventional power plants will raise operational challenges to the electric power utilities due to the uncertainty of wind availability. Thus, the Generation Scheduling (GS) among the online generating units has become crucial. This process can be formulated mathematically as an optimization problem. The GS problem of wind integrated power system is inherently complex because the formulation involves non-linear operational characteristics of generating units, system and operational constraints. As the robust tool is viable to address the chosen problem, the modern bio-inspired algorithm namely, Grey Wolf Optimization (GWO) algorithm is chosen as the main optimization tool. The intended algorithm is implemented on the standard test systems and the attained numerical results are compared with the earlier reports. The comparison clearly indicates the intended tool is robust and a promising alternative for solving GS problems.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.357-357
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• 2006

Many industrial sources of proteins can be used as raw materials to produce films, molded materials, and various hollow items either by "casting" techniques or by "thermoplastic processing". Combining proteins with natural fibbers, paper or biodegradable polyesters is very promising to form biodegradable composites witch take advantage of the barrier and mechanical properties of each component. Using nano-fillers to form nanocomposites has also been shown to be interesting to improve properties. Production, with low transformation cost, of protein based materials to form biodegradable materials with controlled functional properties for food uses, medical uses, packaging, agriculture, controlled release systems, etc. is discussed.

• Transactions on Electrical and Electronic Materials
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• 제11권3호
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• pp.106-111
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• 2010

The convergence of significantly different and disparate technologies such as spintronics, carbon nano tube field effect transistors, photon and bio-responsive molecular switches, memristor and memristive systems and metamaterials, coupled with energy scavenging sources are gaining a renewed focus in the quest for new products. This paper will provide an insight into an anticipated technological revolution and will highlight a futuristic Roadmap to capture opportunities that are brought about as the results of formulation of new circuit components basically driven by emergence of nanoscale materials as part of System on System integration. Challenges as the result of new lumped components such as memristor, metamaterial-based lumped components and the like that will challenge the designers' comfort zone will also be discussed.

• 한국염색가공학회지
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• 제20권4호
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• pp.1-7
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• 2008

Methacryloxypropyl trimethoxysilane (MAPTMS), a hybrid organic-inorganic monomer, was photografted onto PET fabric using benzophenone (BP) as a photoinitiator. It was found that a UV energy of 43.2J/$cm^2$ was required to optimally photograft the MAPTMS onto PET fabrics which was applied with an aqueous formulation of 10% MAPTMS, 20% BP and 0.5% N-Methyldiethanol amine (MDEA). The MDEA additive was efficient in reducing atmospheric oxygen inhibition of polymer radicals which eliminated compulsory nitrogen inerting. The surface grafting of PET fabrics was verified by fourier transform infrared spectroscopy (FT-IR) and scanning electron spectroscopy (SEM). The grafted PET fabrics with the hybrid monomer showed higher thermal stability due to the introduced silane component in the monomer as ascertained by higher char content at 800$^{\circ}C$, which increased to 14.5% for the 15.8% grafting compared to 8.2% for the untreated.

• 한국응용과학기술학회지
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• 제39권6호
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• pp.924-931
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• 2022

Undenatured castor oil and trimethylolpropane (TMP) were used to obtain bio-based water-based polyurethane. Isophorone diisocyanate (IPDI) was incorporated into the formulation to obtain a transparent film, and ethylenediamine (EDA) was used for chain extension. In order to measure the change in physical properties according to the contents of castor oil and TMP, each tensile strength, elongation, and abrasion resistance test was conducted. As the contents of castor oil and TMP increased, the tensile strength increased, the elongation decreased, and the surface hardened strongly as the respective contents increased.

• Applied Biological Chemistry
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• 제47권3호
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• pp.321-324
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• 2004

왕겨를 가연성 담체로 하는 새로운 훈연제의 실용적 가치를 평가하기 위하여 살충제와 살균제를 포함하는 7종의 봉상 훈연제를 제제하고 연소성을 측정하여 시판 중인 과립훈연제와 비교하였다. 오이를 재배 중인 연동하우스에서 fenarimol 과립훈연제를 처리하고 유효성분 분포를 조사하여 농약 처리의 균일성을 검증하였다. 또한 오이 노균병과 토마토 역병에 대한 예방 효과를 측정하여 수화제와 비교하였다. 왕겨를 가연성 담체로 하고 산화제로 염소산나트륨을 첨가한 봉상 훈연제는 여러 가지 농약에 대하여 높은 훈연율을 나타내었으며, 모두 시판되고 있는 과립훈연제보다 더 높았다. 오이를 재배하고 있는 연동하우스$(1,000\;m^2)$의 5곳에 fenarimol 과립훈연제를 처리하고 조사한 9개 지점의 지표면에서는 $26.2{\pm}7.7\;ng/cm^2$의 유효성분이 검출되었으며, 비교적 균일한 분포를 나타내었다. 또한 살균제 농약을 함유하는 봉상 훈연제는 오이 노균병과 토마토 역병에 대한 예방 효과가 시판되고 있는 수화제와 동등하고 약해 유발이 없어서 농약 제형으로 손색이 없었다.

• 농약과학회지
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• 제12권4호
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• pp.368-374
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• 2008

길항력이 있는 그람음성균들의 생물적 방제제로 성공적인 개발은 균의 건조와 저장시의 낮은 생존을 때문에 건조제형으로 만드는 것은 제한되어있다. 그람음성균의 배양시 높은 염(NaCl)의 첨가는 삼투압 조절제인 osmolyte의 생성을 유도하여 건조 시 생존율을 높인다고 알려져 있다. 그람음성의 길항력을 내는 비병원성 Erwinia carotovora subsp. carotovora(Ecc) 9-3의 건조와 저장시의 염의 영향에 관해 연구하였다. Ecc 9-3의 생장률은 0.5 M의 염이 첨가되어 있는 배지에서 큰 차이가 없었지만 0.7 M의 염이 첨가된 배지에서는 급격하게 낮아진 것을 확인하였다. 건조와 저장시의 생존율은 0.5 M의 염을 넣은 배지가 염을 넣지 않은 배지보다 상온건조와 동결건조에서 각각 2배 그리고 3배의 높은 생존율을 얻었다. 건조 후 저장에서도 역시 염이 높을수록 Ecc 9-3의 생존율이 더 높았다. 그리고 상온건조와 동결건조 모두 $4^{\circ}C$에 저장하였을 때 생존율에 큰 차이가 없었다. 그러나 생존율은 $27^{\circ}C$, $37^{\circ}C$에 저장하였을 때 염의 농도가 높을수록 생존율이 증가하였다. 첨가제 실험에서는 lactose가 동결건조와 상온건조 모두에 영향을 주었고 dextrin은 상온건조에 큰 영향을 주었다.