• 한국유기농업학회지
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• 제21권3호
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• pp.381-389
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• 2013

본 연구는 보리와 완두 혼파 포장에서 유기질소질 비료의 시용 수준이 건물생산성, 질소 고정 그리고 이동율 및 이동량을 측정하기 위하여 실시하였다. 처리는 유기질소 40kg, 80kg, 그리고 120kg/ha의 3처리와 질소고정 측정을 위해 대조구로 보리단파구를 각 처리마다 배치하였다. 난괴법 3처리 3반복으로 처리하여 3월부터 6월까지 재배하였다. 보리는 40kg/ha와 완두 80kg/ha를 파종 후 발아를 촉진하기 위하여 흑색 비닐을 멀칭하였다. 질소 고정을 측정하기 위하여 99.8원자% $15N(NH_4)_2SO_4$를 4월 15일 ha당 1kg 수준으로 증류수에 혼합하여 $30{\times}20cm$ 쿼드랏에 시용 하였다. 공중질소 고정율은 32.4%에서 0% 사이였다. 보리에서 완두에로의 질소 이동률은 차이법에서 47.6%에서 21.8% 사이 그리고 동위원소 희석액 처리법에서 24.6%와 21.4%를 나타냈다. 이동량은 차이법에서 92.8kg/ha에서 41.9kg/ha 및 49.7kg 반면 120kg N 유기질 시용구는 동위원소희석법에서는 질소이동이 일어나지 않은 것으로 나타났다. 결론적으로 유기질 비료의 증가에 따른 두과작물의 공중질소고정 향상, 화본과 작물로의 질소이동효과가 분명하지 않았다.

• Journal of Biosystems Engineering
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• 제42권1호
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• pp.56-61
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• 2017

Purpose: High energy requirement and long cooking time are limiting consumption of pigeon pea (Cajanus cajan), a nutritious food. This study was performed to estimate energy and time demand by different methods of cooking pigeon pea. Methods: Pigeon pea (150 g) was soaked in 2.0 L of water at ambient temperature ($29{\pm} 2^{\circ}C$) to determine hydration behavior. Cooking experiments were conducted using aluminum and pressure-cooking pots. Efficiency of cooking was evaluated using four types of cooking appliances (kerosene, liquefied petroleum gas (LPG), electric, and charcoal stoves). Normal (continuous heating until the food was satisfactorily cooked) and control (controlling the energy input to closely match the actual energy required) cooking were conducted. Energy requirement and duration of cooking were determined using standard procedures. Results: Soaking increased moisture content from 11.99 to 30.01% in 90 min, while water absorption rate decreased with soaking duration. In cooking 150 g of pigeon pea using kerosene stove, presoaked normal pressure-pot cooking method consumed the least energy (10 800 kJ) and time (205 min), while unsoaked normal cooking consumed the highest energy (18 450 kJ) and time (336 min). Using LPG stove, unsoaked normal cooking method required the highest energy (52 470 kJ), while presoaked control pressure-pot required the least energy (14 405 kJ). For electric stove, the lowest energy (15 560 kJ) and shortest duration (105 min) were recorded during control cooking of presoaked sample in the pressure-pot. Conclusions: Control cooking was not practicable using charcoal stove. Generally, kerosene stove consumed the least energy, while electric stove was found to have the shortest duration of cooking.

• 전기학회논문지
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• 제67권7호
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• pp.860-864
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• 2018

The signal of space charge distribution measured in polymer insulating materials by the PEA has some noises due to the system circuits and the ringing phenomena in the sensor of PVDF and so on forth. It's magnitude mainly depends on the thickness of the insulation material, and it is also affected by the attenuation and dispersion when traveling in a dielectric material. In order to make it reliable, the correcting process for the signal is essential. In this study, we proposed the new deconvolution process on the measured signal of space charge distribution in the flat XLPE insulator, and developed a new signal processing algorithm. Using this, we could improve the reliability of the measured signal much and analyze the effects of space charge clearly in materials.

• Macromolecular Research
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• 제16권7호
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• pp.614-619
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• 2008

Copolymers of phenyl alkyl acrylates/methacrylates are used clinically as soft materials for the foldable intraocular lens (IOL) to treat cataracts. In this study, copolymers of 2-phenylethyl acrylate (PEA) and 2-phenylethyl methacrylate (PEMA) of various compositions were prepared using free radical polymerization in solution. The composition of the copolymers was determined by $^1H$-NMR analysis. The reactivity ratios of the monomers were calculated using the conventional Fineman-Ross or Kelen-Tudos method. The reactivity ratio of PEA ($r_1$) and PEMA ($r_2$) were estimated to be 0.280 and 2.085 using the Kelen-Tudos method, respectively. These values suggest that PEMA is more reactive in copolymerization than PEA, and the copolymers will have a higher content of PEMA units. The glass transition temperature ($T_g$) of the copolymers increased with increasing PEMA content. The molecular weight and polydispersity indices ($M_w/M_n$) of the polymers were determined by GPC. Overall, these results are expected to be quite useful in applications to foldable soft IOL materials.

• 한국전기전자재료학회논문지
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• 제15권2호
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• pp.127-132
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• 2002

Space charge distributions and behaviors in silane crosslinked polyethylene(SXLPE)/ crosslinked polyethylene(XLPE) laminates were investigated using a pulsed electroacoustic (PEA) method. In case of monolayer, XLPE shows heterocharge while SXLPE shows homocharge. It was observed that charges were accumulated at the interface of SXLPE/XLPE laminate when applied electric field was more than 20kV/mm. The charge profile at various temperatures was also acquired using temperature-controllable PEA system. Although applied electric field is only 8.6 kV.mm, positive interfacial charge starts to appear near 50$^{\circ}C$. It was found that the interfacial charge behavior of SXLPE/XLPE laminate under low voltage at high temperature is corresponding to that under high voltage at room temperature.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.84-87
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• 2001

Space charge formation at high temperature was investigated in several polymers using pulsed electro-acoustic (PEA) method. In SXLPE, homocharge is found and increased as an increase of temperature. In a charge of polarity of poling voltage(positive to negative), space charge mainly cause of hole injection. In Ionomer, heterocharge is found because of ion. As an increase of temperature heterocharge is also increased. In PET, As an increase of temperature homocharge is decreased.

• 분석과학
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• 제35권4호
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• pp.153-160
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• 2022

A green spectrophotometric method for the determination of cyanide has been proposed using, a green reagent, aqueous extract of blue butterfly pea. The test tube was filled with anthocyanin rich extract (pH 6) and cyanide solution. The reaction was kept constant for 10 minutes at room temperature. The reaction mixture changed color from blue to green as the amount of CN-ions increased. The 620 nm peak intensity increased with CN concentration. Therefore, this wavelength was used for all cyanide analyses. The cyanide calibration curve had a linear range of 0.25-1.00, 1.00-4.00, and 4.00-10.00 mg/L, with a satisfactory correlation coefficient of 0.99 and a LOD of 0.57 mg/L. The recovery ranged from 8.33 to 76.94 percent, indicating that this method is inaccurate at low cyanide concentrations. The intra-day and intermediate precision relative deviations were 0.391-0.871 % and 1.112-1.583 %. An H-bond forms between the C-4 group of the B-carbonyl ring and the HCN molecule according to the B3LYP/TZVP calculation. The method is convenient for cyanide concentrations above the LOQ of 1.09 mg/L, cost-effective, and capable of reducing toxic solvents with acceptable precision. The method could also be used to detect total cyanide in biological, environmental, and industrial waste samples.

• 한국치위생학회지
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• 제10권4호
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• pp.577-584
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• 2010

Objectives : The purpose of this study was to examine the relationship of toothpaste-squeezing methods to the amount of toothpaste used among adults. Methods : The subjects in this study were 227 freshmen in a local college. After the intent of a survey was explained by this researcher, how much dentifrice they used was checked to ensure statistical objectivity, and then a survey was conducted. The collected data were analyzed with a SPSS WIN 13.0 program. Results : The findings of the study were as follows:1. As for connections between the way of squeezing and the amount used, the usual amount used, the amount used by horizontal squeezing and the amount used by pea-sized squeezing were respectively 1.12g, 0.66g and 0.46g. The amount used by horizontal squeezing and pea-sized squeezing was less than the usual amount used by 0.46g(41%) and 0.66g(59%) respectively.2. Gender, residential area, educational experiences and daily mean toothbrushing frequency made no differences to the amount of toothpaste used.3. The students who normally used a larger amount of toothpaste used a greater amount of toothpaste as well when they utilized horizontal squeezing and pea-sized squeezing, and the larger amount used by horizontal squeezing led to the greater amount used by pea-sized squeezing. Conclusions : As there were large disparities in the amount of toothpaste used according to the squeezing methods, systematic research efforts should be directed into setting the standard for the recommended amount of toothpaste used for adults and into squeezing method so that they could brush their teeth in an effective manner by using the minimum amount of toothpaste.

• Current Research on Agriculture and Life Sciences
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• 제11권
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• pp.11-17
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• 1993

완두에 있어서 보다 효율적인 형질전환 방법을 모색하고 형질전환된 개체를 얻고자 본 실험을 수행하여 얻어진 결과는 다음과 같다. 형질전환은 발아중인 완두의 생장점(shoot tip)을 제거한 다음 T-DNA내에 GUS gene과 neomycin phosphotransferase II gene이 들어있는 binary vector를 가진 Agrobacterium tumefaciens를 생장점을 제거한 부위에 감염시켰다. 감염 후 새로 형성된 shoot는 개체당 4~5개였으며, 그중 GUS유전자가 발현하는 shoot만을 정상적인 식물체로 분화 시켰다. 감염부위에서 형성된 shoot에서의 GUS유전자의 발현빈도는 10%내외였다. 이들 개체로 부터 genomic DNA를 분리하여 Dot blot hybridization분석 결과 T-DNA가 식물체 내에 존재함을 알 수 있었고, 수확한 종자를 발아시켜 Sorthern blot hybridization한 결과 T-DNA가 다음세대로 전달되었음이 확인되었으며 형질전환율은 2%이내였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.201-204
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• 2008

The use of the pulsed electro acoustic (PEA) method allowed us to perform the direct observations of spatio-temporal charge distributions in Electric double layer capacitors (EDLCs) based on polarizable nanoporous carbonaceous electrode. The negative charge density became the maximum, about 205 C/$m^3$ at the region where was near to collector layer in EDLCs for case $V_{DC}$ = 2.5 V, while the positively charged density became the maximum, about 61.1 C/$m^3$ at the region where it was located around the cathode layer. The PEA measurement used here is a very useful method to quantitively investigates the spatio-temporal charge distribution in EDLCs.