• Journal of Biosystems Engineering
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• v.24 no.3
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• pp.235-242
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• 1999

This study was conducted to develop a grain moisture meter using microwave free space transmission technique at X-band frequency. The 10.5GHz microwave oscillator using a dielectric resonator was designed and fabricated to transmit electromagnetic wave through standard horn antenna to a sample holder with the wetted Hwasung and Chuchung rough rice(12.00∼26.25%). To detect the output voltage of transmitted wave from receiving horn antenna, the detector was composed of shottkey diode and RF impedance matching circuit. The regression model for measurement of grain moisture content was developed. Its correlation coefficient and standard error of prediction (SEP) were found to be 0.9882 and 0.657 respectively between measure and predicted moisture contents.

• Resources Recycling
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• v.28 no.3
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• pp.53-58
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• 2019

Pb dross has been generated from recycling processes of waste acid lead batteries, and proper treatment of Pb dross was required because it contains As component, which has been found to be toxic. This study is aimed at concentrating As component by magnetic separation of ground product obtained from ball and mixer milling of Pb dross. No arsenic component was detected in the non-magnetic product of 10000 G magnetic separation using ground product with $-150{\mu}m$ by ball milling, and As could be concentrated upto 18.87 % by further 2000 G magnetic separation. The ball mill ground product with over $300{\mu}m$ was ground again by mixer mill to less than $150{\mu}m$, and then magnetic-separated by 4000 G followed by 2000 G magnet. The As component was concentrated upto 21.021 % in the magnetic fraction of 2000 G. It was confirmed that As component exsit as $Fe_2As$ by XRD measrument. These results indicate that As component could be concentrated from 0.6 % in the Pb dross to 21.021 % in the magnetic fraction by milling followed by magnetic separation.

• Resources Recycling
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• v.32 no.3
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• pp.18-25
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• 2023

Sericite was ground with or without additives (LiNO₃ or TiO₂) using a planetary mill. The resultant ground products included the average particle size of 2-3 ㎛ (sericite only or sericite+LiNO₃) and 0.5-0.6 ㎛ (sericite+TiO₂) were obtained within 10 minutes of grinding time. respectively. In the grinding of the sericite without any addictive, the particle size initially decreased, but, as grinding time elapsed thereafter, agglomerates were formed and D50 increased over 10 ㎛. In contrast, when the additive was added, the particle size decreased as the grinding time elapsed and any aggregation was relatively not noticeable, compared with the grinding of the sericite only. As a result of measuring the zeta potential for the raw or the ground samples, variation of the zeta potential values according to pH at the early stage of the grinding with the addictives was gentler than that at the final stage of grinding, which showed the relatively similar trend to the pH-zeta potential correlation in grinding of raw sericite. In addition, as a result of the disintegration experiment through ultrasonic excitation, D50 decreased rapidly only until the disintegration time of about 50 minutes.

• Research in Plant Disease
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• v.20 no.2
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• pp.112-118
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• 2014

A liquid bio-formulation containing chitinolytic bacteria, chitin and their products was assessed for its potential biological control against root-knot nematodes on cucumber. The bio-formulation was prepared by cultures of three chitinolytic bacteria, Chromobacterium sp. strain C-61, Lysobacter engymogenes and Serratia plymuthica in minimal medium supplemented with chitin. Under pot conditions, the bio-formulation showed better growth of cucumber plants, and less root galls and population density of Meloidogyne spp. than control media without the bio-formulation. In a greenhouse, 75-fold diluted bio-formulations were treated instead of water around cucumber plants through hoses for drip irrigation six times at 5-day intervals from the transplanting date. After 30 and 60 days, the treatment provided about 7% and 10% enhancement in the plant height and about 78% and 69% reduction in population density of Meloidogyne spp. in the rhizosphere, respectively. In addition, the experiments showed that the control effects occurred only in the soils contacted with the bio-formulation. Undiluted bio-formulations were drenched three times at 10-day intervals around cucumber plants severely infested with Meloidogyne spp. The treatment showed about 37% plant enhancement without dead plants compared with 37% death in the untreated control, and about 82% nematode reduction. These results suggest that the bio-formulation can be practically used to control the root-knot nematode on cucumber.

• Journal of Biosystems Engineering
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• v.25 no.2
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• pp.97-106
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• 2000

To develop the grain moisture meter using microwave free space transmission technique, a 10.5GHz microwave signal with the power of 11mW generated by an oscillar with a dielectric resonator is transmitted to an isolator and radiated from a transmitting $2{\times}2$ microstrip patch array antenna into the sample holder filled with the 12 to 26%w.b. of Korean Hwawung paddy rice. the microwave signal, attenuated through the grain with moisture, is collected by a receiving $2{\times}2$ microstrip patch array antenna and detected using a Shottky diode with excellent high frequency characteristic. A pair of light and simple microstrip patch array antenna for measurement of grain moisture content is designed and implemented on atenflon substrate with trleative dielectric constant of 2.6 and thickness of 0.54 by using Ensemble ver. 4.02 software. The aperture of microstrip patch arrays is 41 mm width and 24mm high. The characteristics of microstrip patch antenna such as grain. return loss, and bandwidth are 11.35dBi, -38dB and 0.35GHz($50^{\circ}$ at far-field pattern of E and H plane. The width of the sample holder is large enough to cover the signal between the antennas temperature and bulk density respectively. The calibration model for measurement of grain moisture content is proposed to reduce the effects of fluectuations in bulk density and temperature which give serious errors for the measurements . From the results of regression analysis using the statistically analysis method, the moisture content of grain samples (MC(%)) is expressed in terms of the output voltage(v), temperature (t), and bulk density of samples(${\rho}b$)as follows ;$$MC(%)\;=\;(-3.9838{\times}10^{-8}{\times}v^{3}+8.023{\times}10^{-6}{\times}v^{2}-0.0011{\times}v-0.0004{\times}t+0.1706){\frac{1}{{\rho}b}}{\times}100$ Its determination coefficient, standard error of prediction(SEP) and bias were found to be 0.9855, 0.479%w.b. and -0.0.369 %w.b. respectively between measured and predicted moisture contents of the grain samples.

• Korean Journal of Microbiology
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• v.49 no.2
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• pp.112-117
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• 2013

Wheat streak mosaic virus (WSMV), a member of the genus Tritimovirus in Potyviridae, severely impacts wheat and corn seed worldwide, but has yet to be detected in Korea, and hence, every effort should be made to prevent its introduction. To prevent WSMV from entering the country, it is necessary to prepare a specific, sensitive, simple, and fast detection method for routine application to plant quarantine procedures. For this reason, a two-step diagnosis system consisting of RT-PCR and nested PCR is being used for WSMV detection. In addition, a novel positive control was developed for use with the system. WSMV has been detected in seed sweet corn from Japan and seed wheat from USA by a two-step diagnosis system, the details of which are described in this study. After sequence analysis, similarities of 80.6 and 100.0% with other isolates were determined by BLAST. They showed the same topology, which was classified as 4 genotypes by various phylogenetic trees, using a poly protein encoding sequence amplification. In this analysis, WSMV-JSweet-corn2868 (JX845574) is classified as clade B, while WSMV-Uwheat1944-1 (KC754959) and WSMV-Uwheat1944-2 (KC754960) belong to clade D.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.378-384
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• 2015

Nuruk is a fermentation agent, which has been used for the production of traditional Korean alcoholic beverages. The objective of this study was to investigate the effects of temperature on nuruk fermentation. One wheat nuruk sample was fermented at $36^{\circ}C$ for 30 days (TN-A) and another at $45^{\circ}C$ for 10 days followed by $36^{\circ}C$ for 20 days (TN-B). The activities of ${\alpha}$-amylase, glucoamylase, and acidic protease, as well as metabolite contents were measured. Initially, the enzymatic activities increased rapidly regardless of the fermentation temperature. After 3 days of fermentation, the enzymatic activities were maintained in TN-A, but gradually decreased in TN-B until the end of fermentation process. Metabolite analysis using $^1H$-NMR showed that the levels of glucose, glycerol, fructose, mannitol, and lactose initially increased quickly and then decreased in TN-A. However, they initially decreased and then were maintained over the fermentation period in TN-B. The contents of glycine, proline, and serine were higher in TN-A than in TN-B. This study suggests that a constant temperature of approximately $36^{\circ}C$ is appropriate for achieving high amylolytic and proteolytic activities in the production of wheat nuruk.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.133-133
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• 2016

지구온난화와 그에 따른 기후변화로 수자원부족현상이 전지구적으로 나타남에 따라 세계 각국은 물부족 현상을 극복하기 위해 다양한 대처방안을 찾고 있다. 가상수 이론은 전세계적 차원에서 상품에 내재된 가상수를 통해 물을 공급하고 배분함으로써 물부족을 해결할 수 있다는 주장으로서 물부족현상에 처한 세계 각국의 관심을 끌고 있다. 특히 향후 국제적 수준에서 물거래에 대한 조치가 예상됨에 따라 이에 가상수가 국가간에 얼마나 어떠한 형태로 이동하는지 '가상수 이동'에 대한 정보가 필요하게 되었다. 그럼에도 불구하고 지금까지의 가상수 흐름에 대한 정보는 미국이나 일본 등을 중심으로 한 자료뿐이었다. 한국을 중심으로 한국의 관심사를 반영한 가상수 이동에 대한 연구결과는 충분하지 않았다. 따라서 본 연구에서는 전세계적 수준에서의 가상수 이동추이를 한국을 중심으로 분석하도록 한다. 분석수준은 전세계적 수준과 국가간 수준이며, 분석기간은 1989년부터 2014년까지 총 26년이다. 분석 대상은 가상수 교역이 활발한 주요 16개국의 11개 농축산물이다. 분석을 위한 자료로는 UN과 세계식량기구의 자료를 활용해 데이터셋을 구축했다. 분석결과 전세계적 수준에서는 콩, 옥수수, 밀, 보리가 주요 가상수 수출입 품목으로 밝혀졌다. 시기별로는 1999년 까지는 밀의 교역이 압도적이었으나 1999년 이후 콩 가상수의 교역이 증가하고 있는 것으로 파악되었다. 가상수의 유형과 관련해서는 녹색가상수의 교역이 청색가상수보다 압도적으로 많았으며, 국가간의 가상수 이동량은 지속적으로 증가하고 있는 추세임을 알 수 있었다. 가상수의 주요 수출국은 미국을 비롯해 브라질, 아르헨티나, 호주 등 농업대국이 상위권을 차지했고, 주요 수입국은 중국, 일본, 한국 등 동북아시아 국가들이었다. 가상수 수출은 미국이 분석기간 내내 우위를 차지하나, 2000년대 이후 중국의 부상이 눈에 띄는 변화라고 할 수 있다. 가상수 수입과 관련해서는 2000년대 이후 중국의 가상수 수입 증가 추세가 두드러졌다. 국가간 수준의 분석에서는 한국과 미국, 한국과 중국, 한국과 호주 등 한국의 주요 가상수 교역국가간의 흐름을 분석했다. 국가간 수준의 분석에서 특기할 만한 점은 미국에서 한국으로 이동한 전체 가상수의 81퍼센트를 녹색가상수가 차지하며, 한국에서 중국으로 이동한 가상수의 74퍼센트가 축산물 가상수라는 점이었다. 본 연구의 분석결과를 기반으로 해 향후에는 가상수 이동 데이터베이스를 구축할 것이 요구되며, 가상수 이동추이의 변화가 가져올 시나리오에 대한 연구도 필요하다고 할 수 있다.

• 한국해양학회지
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• v.26 no.4
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• pp.324-331
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• 1991

Laboratory experiments were undertaken in mixing chamber to study the water-in-oil emulsion formation tendency, stability and formation rate of 16 crude oils. Arabian, Iran, Dubai, Isthmus and Daekyung crudes showed high emulsion formation tendency and had water contents of 80-90%. Emulsions of crude oils of middle East were very stable, while Isthmus and Daekyung sudes formed unstable emulsion. Emulsion formation tendency rate, and stability showed significant correlations with asphaltene content of crude oil. To evaluate the possibility of preventing mousse formation, inhibition ability of several dispersants and demulsifier was tested. They inhibited mousse formation at 0.1-0.2% concentrations (v/v). Emulsion inhibition by chemical treatment delayed the time of formation, but did not decrease water content. Demulsifying ability of dispersants and demulsifier was tested because biscous emulsion causes formidable problems in skimming, pumping and recovery operation. British demulsifier Alcohol 0 showed excellent emulsion breaking efficiency at 0.1% of emulsion Vol..

• Journal of Korea Foresty Energy
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• v.22 no.3
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• pp.49-56
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• 2003

As a part of agricultural utilization of charcoal and pyroligneous acid, the effect of wood carbonization products on the growth of red pepper and soil microorganisms was investigated. The treatment of charcoal and pyroligneous acid provided good growth conditions to microorganisms through neutralizing soil acidity and improving the physicochemical properties of soil. Therefore the density of useful microorganism in the soil has been increased. In the growth of red pepper, the length, diameter, and the fruit numbers of red pepper have been increased by treating with wood carbonization products. It was especially shown that yield has increased about 50% in the fruit number, by treating charcoal 1kg, 1000 time-diluted solution of pyroligneous acid and bacteria, compared with the control. It was estimated that increasing the length of seedling and the diameter of red pepper stem contributed to the resistance against the prerequisites of various environmental changes in open field. Therefore, the final yield would be increased. In the antagonism experiment of red pepper mold (Colletotrichum gloeosporioides), the mold became extinct in the 2- and 10-time diluted solution of pyroligneous acid, compared with the control. On the other hand, their growth speed was delayed in the 100- and 1000 time-diluted solution.