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

• 한국초지조사료학회지
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• 제28권2호
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• pp.129-138
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• 2008

Demand for alternatives to petroleum is increasing the production of biofuels from food crops such as corn, soybeans, sorghum and sugarcane, etc. At least for the next 5 years, ethanol demand will be increased greatly in the United States and in the world. Presently, most ethanol produced in the United States is corn (Zea mays) ethanol. As a result, especially in the Americas and Southeast Asia, agricultural land is diverted to biofuel production. Even though biofuel industry has many advantage including national security, economical, energetical and sustainable impacts, it is driving grain prices up and creating considerable concern about the potential negative impacts on a wide range of food products that depend on gain : chicken, pork, beef, and dairy products such as milk, cheese, yoghurt, cream and ice cream. Feedstock crops are crops such as switchgrass(Panicum virgatum, L.), corn stover and grasses that can be used in industrial processes such as fermentation into alcohol fuels. Feedstock is no compete with food. Furthermore it is friendly environmental bioenergy crops. In Korea, with increasing demand for fossil fuels the exploration of alternative sources of liquid fuel is inevitable. I suggest Korea need to research and to develop actively on feedstock for biofuel production through this review.

• Korean Chemical Engineering Research
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• 제50권2호
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• pp.223-228
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• 2012

ABS와 폴리에틸렌(Polyethylene, PE) 및 ABS-PE 혼합물의 저온열분해를 회분식 반응기를 이용하여 상압 및 $450^{\circ}C$에서 실행하였다. 열분해 시간은 20~80분까지 하였고 열분해로 생성된 성분은 지식경제부에서 고시한 증류성상온도에 따라 가스, 가솔린, 등유, 경유, 중유로 분류하였다. ABS와 PE의 혼합 폐플라스틱의 열분해 전환율은 PE의 함량이 증가할수록 증가하는 것으로 나타났다. 열분해생성물의 수율은 PE의 함량이 높을수록 중유 > 가스 > 가솔린 > 경유 > 등유 순으로 회수되었다.

• Journal of the Korean Wood Science and Technology
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• 제28권3호
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• pp.42-51
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• 2000

떡갈나무의 부위별 추출물에 대한 항균활성 및 항산화활성을 시험하였다. 항균활성은 paper disk법과 bioautography법으로 시험하였다. 잎으로부터 추출된 ethyl acetate 가용부는 Klebsiella pneumoniae균에 대해서 가장 강한 항균력을 나타냈다. 수피로부터 추출된 ethyl acetate 가용부는 Bacillus subtilis, Klebsiella pneumoniae균에 대해 항균효과가 우수하였다. 목절부의 에탄올 추출물은 Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae 및 Vibrio parahaemolyticus균에 대해서 저해효과가 가장 높게 나타났다. 떡갈나무 에탄올 추출물의 항균활성은 잎, 수피, 목질부의 순으로 높게 나타났다. Bioautography법에 의한 항균활성은 목질부 에탄올 추출물에 있어서 Rf치 0.41~0.63 영역의 물질이 가장 강한 저해를 나타냈다. 떡갈나무의 부위별 추출물에 대한 항산화활성 시험 결과, 잎 추출물에서는 petroleum ether 가용부가 매우 낮은 항산화활성을 나타냈으나, ethyl acetate 불용부에서는 높은 항산화활성을 나타냈다. 수피와 목질부의 추출물에 있어서. petroleum ether 가용부를 제외한 나머지 분획물의 항산화활성은 BHT의 항산화 성보다 약 2배 정도 높은 수치를 보였다.

• International Journal of Advanced Culture Technology
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• 제4권1호
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• pp.1-9
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• 2016

The demand for energy in Thailand has been continually increasing as the economic and social country grows. Approximately 60% of Thailand's primary energy is imported, mostly petroleum products. In 2008 Thailand's total energy consumption was 80,971 ktoe and the net price of energy imported was up to 1,161 billion Baht which is equivalent to 12.8% of GDP at the current price. The energy consumption or energy demand has been growing at an annual compounded growth rate of 6.42% and the peak electric power demand and electricity consumption was recorded at 22,568 MW and 148,264 GWh and grew at a rate of 7.0% and 7.5% per annum during the period from 1989 to 2008. The gross agriculture production in 2008 was recorded at 135.4 Mt which represents agriculture residue for energy at 65.73 Mt, which is equivalent to energy potential of about 561.64 PJ or 13,292 ktoe an increase in average of 5.59% and 5.44% per year respectively. The agricultural residues can converted to 15,600 GWh/year or 1,780 MW of power capacity. So, if government sector plan to install small biomass gasification for electricity generation 200 kW for Community. The residue agricultural is available for 8,900 plants nationwide. The small biomass power generation for electricity generation not only to reduce the energy imports, it also makes the job and income for people in rural areas as well. This paper's aim is to report the energy situation in Thailand and has studied 5 main agricultural products with high residue energy potential namely sugarcane, paddy, oil palm, cassava, and maize appropriate for small electricity production. These agricultural products can be found planted in many rural areas throughout Thailand. Finally, discuss the situation, methods and policies which the government uses to promote small private power producers supplying electricity into the grid.

• Journal of the Korean Wood Science and Technology
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• 제46권4호
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• pp.393-401
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• 2018

Natural fibers derived from lignocellulosic materials are considered to be more environment-friendly than petroleum-based synthetic fibers. Several natural fibers, such as seedpod fibers, have a potential for development, including kapok and balsa fibers. The characteristics of both fibers were evaluated to determine their suitability for specific valuable applications. The purpose of this study was to analyze some important fundamental properties of kapok and balsa fibers, including their dimensions, morphology, chemical components, and wettability. The results showed that the average fiber lengths for kapok and balsa were 1.63 and 1.30 cm, respectively. Kapok and balsa fibers had thin cell walls and large lumens filled with air. The kapok fiber was composed of 38.09% ${\alpha}-cellulose$, 14.09% lignin, and 2.34% wax content, whereas the balsa fiber was composed 44.62% ${\alpha}-cellulose$, 16.60% lignin, and 2.29% wax content. The characteristics of kapok and balsa fibers were examined by X-ray diffraction, Fourier-transform infrared spectroscopy and differential scanning calorimetry analyses. The contact angle of the distilled water on kapok and balsa fibers was more than $90^{\circ}$, indicating that both fibers are hydrophobic with low wettability properties because of to the presence of wax on the fiber surface.

• 한국환경과학회지
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• 제20권12호
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• pp.1617-1624
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• 2011

Caustic (NaOH) solution is used to remove $H_2S$ from hydrocarbon streams in petroleum refining industry, gradually being, so called, spent sulfidic caustic (SSC) which has high levels of $H_2S$ and alkalinity. Thus, SSC can be used as an electron donor and a buffering agent for autotrophic denitrification. As SSC, however, contains some non-biodegradable organics, air stripping was conducted to remove the non-biodegradable organics. As a result, over 93 % of the non-biodegradable organics was removed within 30 min of aeration. Then, $Na_2S_2O_3{\cdot}5H_2O$, methanol and organic matters, which are produced from a biodiesel production plant, were added to reform the air-stripped SSC and their products being referred to new sulfidic caustics (NSCs) I, II and III, respectively. Thereafter, to investigate the effect of these products on the removal of COD and TN, these products were injected to a biological nitrogen removal (BNR) process, resulting in additional 44 % TN removal without noticeable increase in the effluent COD level. Therefore, it can be said that the BNR process is a promising option to treat NSC as demonstrated in this study whose results can be useful for developing resource recovery technologies.

• 한국건설관리학회논문집
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• 제10권3호
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• pp.122-129
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• 2009

건설 관련 기술 및 시장은 최근 시간과 장소를 떠나 글로벌 시장이라는 하나의 울타리 내에서 이루어지고 있다. 또한, 대기업 중심이었던 해외건설시장에서 중소기업의 비중이 확대되고 있는 시점에서 이들 건설기업의 이윤확대를 위해서는 더욱 효율적이고 생산적인 사업구조 전략이 절실히 요구된다. 이러한 기업의 전략을 위해 건설기업들은 일반적으로 타 기업과의 비교분석을 통해 부족한 점을 인식하고 발전시키기 위한 벤치마킹을 실시하고 있다. 이에 본 논문은 세계 건설업체의 다양한 사업구조전략 및 변화모습을 분석하여 선진 건설업체를 선정하는 한편 이들 기업의 전략 특성을 살펴보고자 한다. 또, 벤치마킹을 위한 선진기업의 선정 방법을 소개하는 또다른 목적을 가질 수 있겠다. 선진 건설업체를 선정하기 위해 시장점유율(매출)변화 분석, 건설 상품별 전문성 분석, 그리고 사업 포트폴리오전략 분석을 방법론으로 이용하였으며 자료는 ENR지에서 발표되는 세계 건설기업의 매출과 상품별 비중을 참고하였다.

• 한국자동차공학회논문집
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• 제13권3호
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• pp.138-145
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• 2005

Recently, the tightening of an available crude oil supplies has resulted in the development of intense consciousness for saving fuels. At the same time, some research programs have been launched to secure substitute energy sources for petroleum-derived fuels, and to reduce unhealthy products, such as CO, HC, NOx and smoke. To keep up with these trends in society, the regulation affecting diesel smoke may be greatly strengthened in a short time. In not too distant future, LPG and LNG are the most hopeful substitute fuels for automobile and truck uses. This paper discusses how to use such gaseous fuels in a diesel engine, and how much methods for introducing these fuels affect the engine performance.

• 생약학회지
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• 제30권2호
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• pp.105-110
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• 1999

In our continuing search for new antineoplastic agents from natural products, one hundred and thirty-five herbal drugs were extracted with petroleum ether/ether (1:1), ethyl acetate and methyl alcohol, successively and their cytotoxicities were evaluated against A549 (human lung carcinoma) and SK-OV-3(human ovary adenocarcinoma) cell lines. Among them, fifteen kinds of ether extracts, eighteen kinds of ethyl acetate extracts and seven kinds of methanol extracts showed significant cytotoxic activities (above 70% inhibition) against A549 cell lines at a concentration of $40\;{\mu}g/ml,$ while ten kinds of ether extracts, thirteen kinds of ethyl acetate extracts and six kinds of methanol extracts demonstrated significant cytotoxic activities against SK-OV-3 cell lines at the above same concentration.