• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.7
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• pp.585-593
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• 2008

In this work, we report several experimental data capable of evaluating the phase transformation characteristics of GeSbTe pseudobinary thin films comprehensively utilized as phase change materials. The phase transformation of the GeSbTe thin films was confirmed by XRD measurement from amorphous to hexagonal structure via fee structure except for $Ge_8Sb_2Te_{11}$. In addition, X-ray photoelectron spectra analysis revealed to weaken Ge-Te bond for $Ge_2Sb_2Te_5$ and to strengthen the bonds of all elements for $Ge_8Sb_2Te_{11}$ during the amorphous to crystalline transition. The values of optical energy gap $(E_{OP})$ were around 0.71 and 0.50 eV and the slopes of absorption in extended region (B) were ${\sim}5.1{\times}10^5$ and ${\sim}10{\times}10^5cm^{-1}{\cdot}V^{-1}$ for the amorphous and fcc-crystalline structures, respectively. Finally, the kinetics of amorphous-to-crystalline phase change on the GeSbTe films was characterized using a nano-pulse scanner with 658-nm laser diode (power; $1{\sim}17$ mW, pulse duration; $10{\sim}460$ ns).

• Korean Journal of Agricultural Science
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• v.37 no.1
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• pp.73-80
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• 2010

Functional and nutritional components of 7 cultivars of Chinese cabbage (CC; Brassica rapa subspecies campestris) from China were analyzed to compare the effects of soil pH (6.9 vs. 7.6). The CC grew on the soil of pH6.9 (CC-6.9) contained significantly increased amounts (2.3~4-fold) of pectin, crude protein, vitamin C and vitamin E compared to the control. The contents of ash and minerals (Ca, Fe, Na, Zn, K and Mn) were also significantly increased in CC-6.9. However, CC-6.9 contained 16-75% lower contents of reducing sugars, cellulose and crude fat than CC-7.6. CC-7.6 contained more glucosinolates than CC-6.9; gluconasturtiin (20.68 vs. 0.84 $nmol{\cdot}g^{-1}$ wet wt) and gluconapin (202.55 vs. 0.15 $nmol{\cdot}g^{-1}$ wet wt). In conclusion, CC-6.9 had an improved texture (high pectin and low cellulose) and nutritional value (high in protein, Ca, Fe, Zn, vitamin C, and E), whereas CC-7.6 had better taste (high in reducing sugars) and anticancer functionality (high in glucosinolates).

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.8
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• pp.1010-1014
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• 2007

This study was designed to determine the trans fatty acid (tF A) contents of 41 take-out food items in Daejeon and Chungcheong Province. Total fatty acid composition and tFA contents of samples were determined by gas chromatography (GC) after fat extraction (Folch method). Maximum fat content among the observed samples was obtained from theater popcorn (13.74${/cdot}$38.09%) while minimum content was observed from the glutinous rice doughnut. 31${/cdot}$5.44%). The contents of tFA (g/100 g food) in toasts, glutinous rice doughnut and ggwabaegi (twisted doughnut sold in streets) ranged from 0.02 to 0.56 g while those in fried sweet potatostick (from highway resting place), fried squid and theater popcorn ranged from 0.05 to 3.08 g/100 g. As a result, most samples showed the tFA content as less than 1 g (g/100 g food) except one sample from theater popcorn which contained 3.08 g (g/100 g food) as tFA content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.378-383
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• 2018

The goal of this study was to examine the growth and yield according to planting density in wide-row drill seeding cultivation suitable for mechanized harvesting. We evaluated effects depending on planting densities [row spacing (30, 40, 50, and 60 cm) and plant spacing (10, 15, and 20 cm)] and cultivars ('Hongeon' and 'Arari') on growth and yield of Adzuki Beans (Vigna angularis (Willd.) Ohwi Ohashi). When row spacing decreased, the stem length increased in 'Arari' but decreased in 'Hongeon.' The stem diameter and number of branches in both the cultivars decreased with a decrease in row spacing. The pod height increased with lower planting densities. The greatest height values recorded in 'Hongeon' and 'Arari' were 5.0 cm and 8.8 cm in $30{\times}10cm$ and $50{\times}10cm$ treatments, respectively. The number of pods and number of seeds in both cultivars tended to increase with a decrease in planting density. On the other hand, in 100-seed weight, there was a difference in planting density in 'Hongeon', but no difference in 'Arari'. The highest yield was at the planting density of $40{\times}15cm$ in both 'Hongeon' and 'Arari', $285kg{\cdot}10a^{-1}$ and $374kg{\cdot}10a^{-1}$.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3695-3702
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• 2013

A nickel(II) complex $[Ni(H_2biim)_2(H_2O)_2](ClO_4)_2{\cdot}H_2O$ (1) of biimidazole ligand has been synthesized and characterized (Where $H_2biim$ = 2,2'-biimidazole). The single crystal X-ray diffraction of the complex shows a dimeric structure with six coordinated psudo-octahedral geometry. The cyclic voltammograms of complex exhibited one quasireversible reduction wave ($E_{pc}=-0.61V$) and an irreversible oxidation wave ($E_{pa}=1.28V$) in DMF solution. The interaction of the complex with Calf-Thymus DNA (CT-DNA) has been investigated by absorption and fluorescence spectroscopy. The complex is an avid DNA binder with a binding constant value of $1.03{\times}10^5M^{-1}$. The results suggest that the nickel(II) complex bind to CT-DNA via intercalative mode and can quench the fluorescence intensity of EB bind to CT-DNA with $K_{app}$ value of $3.2{\times}10^5M^{-1}$. The complex also shown efficient oxidative cleavage of supercoiled pBR322 DNA in the presence of hydrogen peroxide as oxidizing agent. The DNA cleavage by complex in presence of quenchers; viz. DMSO, KI, $NaN_3$ and EDTA reveals that hydroxyl radical or singlet oxygen mechanism is involved. The complex showed invitro antimicrobial activity against four bacteria and two fungi. The antimicrobial activity was nearer to that of standard drugs and greater than that of the free ligand.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.60-60
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• 2018

오랑캐장구채는 석죽과의 여러해살이풀로 일본 훗카이도, 사할린, 바이칼호에 서식하며, 한국에서는 중부 이북지방의 산지에 자생하는 유용 자생식물로 활용가치가 높다. 분화용 소재로 이용하기 위하여 2017년 7월 31일부터 10월 9일까지 약 10주간 재배조건을 조사하였다. 분화용 오랑캐장구채의 재배는 이색칼라 화분 8, 10, 12호 중 12호 처리구에서 직경, 생체중, 근경 등에서 효과적이었는데 특히, 엽면적은 다른 처리구보다 2배 이상 넓어서 관상용으로 적합하였다. 이식묘의 소질은 162구 트레이의 유묘가 초장, 엽수, 엽면적이 가장 크거나 많았고, 한 cell당 2립씩 파종된 유묘처리구가 엽면적이 넓고 엽록소 함량이 높아 상품성면에서 효과적이었다. 혼합용토는 코코피트:펄라이트(3:1)혼용구가 피트모스:펄라이트(3:1) 혼용구보다 엽면적과 근장이 큰 편이었다. 혼합 비료(N-P-K)는 $600-400-400mg{\cdot}L^{-1}$비료가 첨가된 처리구에서 특히, 초장, 엽수, 엽면적, 엽록소 지수, 근장 및 생체중이 처리별로 가장 우수하여, 원예상토와 유사하거나 그 이상의 효과가 있었다. 기비로는 코트비료 40알 처리구가 근장을 제외한 모든 요인에서 생육이 우수하였다. 오랑캐장구채를 분화용으로 이용하기 위한 재배관리 방법은 차광이 되지 않는 곳에서 추비 $1,000mg{\cdot}L^{-1}$ hyponex 시비 및 왜화제로 $1,000mg{\cdot}L^{-1}$ daminozide를 처리하며, 10주간의 재배를 위해서는 적심을 하지 않는 것이 생육에 효과적이었다.

• Korean Journal of Materials Research
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• v.23 no.12
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• pp.708-713
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• 2013

Graphene oxide has been synthesized by microwave-assisted exfoliation of graphite oxide prepared by modified Hummers method. Graphite was oxidized in a solution of $H_2O_2$ and $KMnO_4$ at $65{\sim}80^{\circ}C$, followed by 10 % $H_2O_2$ solution treatment at $80{\sim}90^{\circ}C$. The graphite oxide was exfoliated under microwave irradiation of 1 kW and was reduced to graphene effectively by hydrazine hydrate ($H_4N_2{\cdot}H_2O$) treatment. The exfoliation of graphene oxide was significantly affected by the microwave irradiation on (heating)/off (cooling) period. An on/off period of 10 s/20 s resulted in much more effective exfoliation than that of 5 s/10 s with the same total treatment time of 10 min. This can be explained by the higher exfoliation temperature of 10 s/20 s. Repetition of the graphite oxidation and exfoliation processes also enhanced the exfoliation of graphene oxide. The thickness of the final graphene products was estimated to be several layers. The D band peaks of the Raman spectra of the final graphene products were quite low, suggesting a high crystal quality.

• Journal of Environmental Science International
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• v.26 no.1
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• pp.119-131
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• 2017

This study evaluated the feasibility of recovering and recycling nitrogen (N) and phosphorus (P) from livestock excreta as struvite ($MgNH_4PO_4{\cdot}6H_2O$) in South Korea. Our experimental results showed that struvite precipitation was a very effective way to recover N and P from livestock excreta. Moreover, our study demonstrated that struvite precipitates from livestock excreta (SPL) contain higher concentrations of N, P, and magnesium (Mg) as compared to compost and liquid manure from livestock excreta. In addition, although SPL contain high concentrations of copper (Cu) and zinc (Zn), they meet the fertilizer criteria for concentrations of heavy metals. In South Korea, SPL cannot currently be used as a fertilizer due to legal constraints. Legal permission for SPL use would offer greater choice in livestock excreta management. In conclusion, recovery and recycling of N and P from livestock excreta as struvite can be an effective tool for managing nutrients in livestock excreta.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.507-516
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• 2008

This research was conducted to elucidate the effect of temperature on the nitrogen removal of municipal wastewater with waste-tire media. The experiments were carried out in laboratory-scale batch reactor and pilot-scale moving bed biofilm reactor filled at a 0.15 filling ratio with waste-tire media, respectively. In batch tests, specific nitrification rate(SNR) with media was 3.4 mg NH$_4^+$-N/g Mixed-Liquor Volatile Suspended Solid(MLVSS)$\cdot$hr, compared with 1.7 mg NH$_4^+$-N/g MLVSS$\cdot$hr without media. In pilot-scale test with media, total nitrogen removal efficiency increased from 53 $\pm$ 8% to 76 $\pm$ 5% as the temperature increased from 9$\sim$10$^{\circ}C$ to 20$\sim$24$^{\circ}C$. At the temperature of 9$\sim$10$^{\circ}C$, 10$\sim$20$^{\circ}C$, and 20$\sim$24$^{\circ}C$, the SNRs were 0.8 $\pm$ 0.5, 3.1 $\pm$ 1.9, and 3.4 $\pm$ 2.1 mg NH$_4^+$-N/g MLVSS$\cdot$hr and the specific denitrification rates(SDNR) were 0.6 $\pm$ 0.2, 1.1 $\pm$ 0.6, 1.4 $\pm$ 0.6 mg NO$_3^-$-N/g MLVSS.hr, respectively. The overall activities of biomass in anaerobic, anoxic, and oxic zones at 20$\sim$24$^{\circ}C$ increased to 22, 20, and 15%, compared with those at 9$\sim$10$^{\circ}C$, respectively. The activity distribution of Nitrosomonas and Nitrobacter also increased with the increase of temperature.

• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.70-76
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• 2010

To investigate the ground water quality status for paprika hydroponics for export, its pH, EC (electrical conductivity) and inorganic ion concentrations were analyzed in Gangwan-do (27 samples), Gyeonsangnam-do (77 samples) and Jeollanam-do (54 samples) from November 2008 to September 2009. The average values of several components in ground water were as follows; 7.20 (6.57~7.54) in pH, 0.31 (0.05~0.49) $dS{\cdot}m^{-1}$ in EC, 97.81 (35.37~161.11) in $HCO_3$, 5.68 (0.45~15.48) in T-N, 0.67 (0.15~0.70) in P, 2.53 (0.59~6.70) in K, 35.68 (4.15~80.70) in Ca, 7.35 (1.46~14.87) in Mg, 17.89 (3.31~34.82) in Na, 0.01 (0~0.05) in Fe, 0.09 (0~0.51) in Mn, 0.06 (0~0.07) in Zn, and 0.03 (0~0.10) $mg{\cdot}L^{-1}$ in Cu, respectively. The values of pH, EC, $HCO_3$, Ca, Mg and Na in ground water were different depending on areas and farms. Frequency rates were 92.6% of pH 5.0~8.0, 89.3% of EC < 0.5 $dS{\cdot}m^{-1}$, 69.5% of $HCO_3$ < 100, 97.5% of Na < 30, 88.5% of Ca < 40, 97.5% of Mg < 20, 90.1% of Fe < 0.05, 99.6% of Mn < 0.6, and 98.3% of Zn < 0.5 $mg{\cdot}L^{-1}$, respectively, which can be used for nutrient fertilizers in hydroponics. The percentage of suitable water quality was 46.3% as 70 sites among the all analyzed ions. The pH value showed high significance of correlations with EC, Mg, $HCO_3$, Na, and Fe. Also the EC value showed high positive significance with T-N, K, Ca, Mg, $HCO_3$, Na and Mn.