• 한국환경과학회지
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• 제20권2호
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• pp.223-229
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• 2011

Toluene desorption of modified activated carbon for microwave irradiation was evaluated. As a virgin GAC reacted from microwave energy, it created an "arcing" between GAC particles in desorption process. The arcing became more and more vigorous and achieved a red flame of GAC. The silica coated GAC(Si/GAC) was developed to prevent arcing phenomenon and temperature control problem. The result shows virgin GAC with 5wt%, 10wt% and 20wt% silica had no arcing and could control temperature very well. However, the adsorption rate of Si/GAC was decreased by coated silica amount due to decreasing surface area of GAC. The 5wt% Si/GAC adsorption rate was quite similar to virgin GAC adsorption rate. After adsorption, the toluene-loaded GAC and Si/GAC was reactivated by 2450MHz MW irradiation with 300W for 5 min. Quantitative desorption of the toluene was achieved at MW irradiation at 300W with desorption efficiencies as high as 98.59% to 84.65%% after four cycles.

• 미생물학회지
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• 제38권2호
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• pp.103-106
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• 2002

사상균류의 세포자체로부터 직접 PCR을 하는 방법은 세포벽 파괴의 어려움 때문에 모든 곰팡이에 적용될 수 없다. 극초단파 조사는 사상균류의 DNA를 추출함에 있어서 그 유용함이 이미 검중된 바 있는데, 본 논문에서는 극초단파 조사를 이용하여 Aspergillus nidulans의 포자로부터 손쉽게 주형 DNA를 얻어 PCR증폭하는 방법을 소개하고자 한다. 본 실험에서는 극초단파 조사시간과 PCR에 필요한 주형 DNA의 양 등을 최적화하였으며, 이렇게 수행된 PCR결과는 single copy유전자를 대상으로도 약 3 kb크기의 산물가지 증폭 가능하여, 형질전환체를 선별하기에 충분한 크기의 산물들도 효과적으로 얻어짐을 보여주었다. 따라서 이 방법은A. nidulans의 형질전환체를 보다 손쉽게, 시간을 절약하여 선별할 수 있는 효과적인 방법이라 생각된다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1534-1535
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• 2005

Highly luminescent efficiency phosphors have been successfully produced by surface modification and microwave irradiation treatment. The SEM image and XRD analysis reveal that the surface morphology of the white-light phosphors can be notably modified by microwave irradiation and exhibit with better crystalline property. The VUV PL spectra show that the microwave irradiation treatment can effectively enhance the luminescent efficiency by a factor of 1.5 times for intensity compared to that without microwave treatment. A further improvement in all visible emission can be made by modifying surface composition through MgO coating on the phosphor powder. These results demonstrate that such a simple approach can provide for improving luminescent efficiency of phosphors for the optoelectronic devices.

• 대한수의학회지
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• 제47권2호
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• pp.203-207
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• 2007

Conventional processing of biological materials including nematode parasites for scanning electron microscopy includes fixation with glutaraldehyde and osmium, followed by dehydration in an ascending grade of ethanol, and finally freeze drying. This procedure takes about 8 to 12 h depending on the characteristics of samples. Microwave irradiation of 2,450 MHz enhance the action of cross-linking fixatives and can greatly accelerate various stages of tissue processing. In this study, samples of nematode parasites, Setaria digitata, were fixed by a combination of conventional chemical fixation and the microwave irradiation during the process. The microwave irradiation was also incorporated in the serial dehydration process with ethanol. The complete procedure from the initial fixation to the completion of dehydration with ethanol was reduced to 1 h with good preservation of the ultrastructural details of the specimens.

• 한국물환경학회지
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• 제30권5호
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• pp.486-490
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• 2014

Industrial use of microwave heating as an alternative to conventional heating is becoming popular mainly due to dramatic reductions in reaction time. Therefore, this work experimentally determined the effect of microwave irradiation on ammonia nitrogen removal in wastewater. The effects of air flow rate (0.3~0.9 L/min), treatment temperature ($70{\sim}100^{\circ}C$), and initial pH (9~11) were characterized. As the air flow rate increased from 0.3 to 0.9 L/min, the ammonia removal rate constant (k) increased from -0.6642 to $-1.0755min^{-1}$. As the temperature increased from 70 to $100^{\circ}C$, k increased -0.0338 to $-1.0755min^{-1}$. As the pH increased from 9 to 11, k increased -0.2443 to $-1.0755min^{-1}$. Ammonia removal was strongly dependent on temperature and pH rather than air flow rate. The results show that microwave irradiation is effective in ammonia nitrogen removal in wastewater due to advantages of fast and effective processing.

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 1994년도 제25회 학술대회 연제 초록
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• pp.12-12
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• 1994

• Bulletin of the Korean Chemical Society
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• 제24권9호
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• pp.1354-1356
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• 2003

• 공업화학
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• 제16권5호
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• pp.653-659
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• 2005

동일한 마이크로파 조사 방식과 전계 강도에 의하여 마이크로파가 에멀젼에 조사될 경우 조사 시간이 길수록 많은 에너지가 에멀젼에 흡수된다. 그 결과로 에멀젼의 온도가 상승하고 점도는 낮아져 분리가 일어난다. 본 연구에서는 에멀젼 분리 효율의 향상을 위하여 마이크로파 조사 방식(연속식(continuous mode), 펄스식(pulsative mode), 주기식(periodical mode))에 의한 분리 효율의 비교 검토와 Sauter 평균 지름(Sauter mean diameter: $D_{32}$)을 이용한 에멀젼의 안정성에 관한 연구를 수행하였다. 각각의 조사 방식에 의하여 600 sec 동안 마이크로파가 조사된 30% W/O형 에멀젼(sample #1)을 24 h 침강시켰을 경우 연속식, 펄스식, 그리고 주기식에서 각각 60.0%, 62.3%, 그리고 96.2%의 오일 회수가 이루어졌고, 물 분리율은 26.5%, 35.0%, 그리고 93.9%를 나타내었다. Sauter 평균 지름($D_{32}$)은 연속식 $47.183{\mu}m$, 펄스식 $111.547{\mu}m$ 그리고 주기식에서 $220.476{\mu}m$로 주기식에서 가장 큰 값을 얻었다.

• 한국물환경학회지
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• 제33권4호
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• pp.387-393
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• 2017

A chemical batch tests were conducted to evaluate if microwave heating enhances phosphorous release from waste activated sludge (WAS) at pH 2.5, 5, 7, 9 and 11. Polyphosphate-accumulating organisms have a unique physiological feature, which releases intracellular polyphosphate granules when they are exposed under high temperature environments. Microwave irradiation was found to encourage large amount of phosphorus release from WAS, depending on pH and temperature conditions. Most of phosphorus was released below $59^{\circ}C$ within 30 min. A marked increase in phosphorus release was observed under alkaline or acidic conditions. However, based on control tests for phosphorus release under different pH conditions without microwave heating, the largest amount of phosphorus released by microwave irradiation was found at pH 7, followed by 5, 9, 11. On the other hand, crystallization was conducted to obtain magnesium ammonium phosphate (MAP) from phosphate released by microwave heating at pH 7. X-ray diffraction analysis confirmed that the recovered crystalline materials were MAP. MAP is an environmentally friendly fertilizer, which slowly releases ammonia and phosphorus in response to the demand of plant root. Thus, the recovered MAP as a phosphate fertilizer is fully expected to play a important role in the reduction of agricultural non-point pollution.

• Journal of Forest and Environmental Science
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• 제31권1호
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• pp.1-6
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• 2015

Microwave assisted biodiesel production from crude Pongamia pinnata oil using homogeneous base catalyst (KOH) was unsuccessful because of considerable soap formation. Therefore, a two step process of biodiesel production from high free fatty acid (FFA) oil was investigated. In first step, crude P. pinnata oil was acid catalyzed using $H_2SO_4$ and acid value of oil was reduced to less than 4 mg KOH/g. Effect of sulfuric acid concentration, alcohol-oil molar ratio and microwave irradiation time on acid value of oil was studied. Result suggested that 1.5% $H_2SO_4$ (w/w), 6:1 methanol oil molar ratio and 3 min microwave irradiation time was sufficient to reduce the acid value of oil from 12 and 22 mg KOH/g to 2.9 and 3.9 mg/KOH/g, respectively. Oil obtained after pretreatment was subsequently used for microwave assisted alkali catalyzed transesterification. A higher biodiesel yield (99.0%) was achieved by adopting two step processes. Microwave energy efficiency during alkali catalyzed transesterification was also investigated. The results suggested a significant energy saving because of reduced reaction time under microwave heating.