• Horticultural Science & Technology
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• v.31 no.2
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• pp.153-158
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• 2013

This research was carried out to investigate silicon (Si) uptake levels by six potted plant species from a nutrient solution supplemented with $K_2SiO_3$. Uniform rooted plants of Dendranthema grandiflorum Ramat., Spathiphyllum patinii N.E. BR., Kalanchoe blossfeldiana, Hedera helix L., Dianthus caryophyllus L., and Euphorbia pulcherrima Willd. were grown in 350 mL boxes, one plant per box, containing a nutrient solution supplemented with either 0, 2.7, or 5.4 mM Si as $K_2SiO_3$. The nutrient solution in each container was adjusted to EC $1.5mS{\cdot}cm^{-1}$ and pH 5.6. The solution in each container was aerated by an 1 m-long polyethylene tube, all connected to a vacuum pump. After 15 days of cultivation in a glasshouse Si contents in the roots and shoots were measured using the colorimetric molybdate method and amount of remaining Si in the nutrient solution was measured using the ICP-AES to calculate the amount of absorption. A simple regression analysis was performed to observe the changes in Si contents in the roots and shoots as affected by concentration of Si supplied to the solution. Among the six species tested, carnation had the greatest and poinsettia the lowest tissue levels of Si concentration in the root, whereas carnation had the greatest and kalanchoe the lowest tissue levels of Si concentration in the shoot. Based on the Si content in the whole plant, Si uptake levels by poinsettia, kalanchoe, and chrysanthemum were low, whereas those by spathiphyllum were intermediate, and those of English ivy and carnation were high. These results indicated that the uptake level of Si by the plant vary depending on plant species.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2005.12a
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• pp.38-45
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• 2005

The egg bags of Korean salamander(Hynobius leechii) were collected from farmlands in Gyeongsangnam-do area. The assumed breeding time, numerical variation of embryos in each egg bag, mortality and the rates of abnormalities were investigated. The toxicity of benomyl, the metabolite carbendazim and BIC which were frequently spread in agricultural area and caused spontaneous embryonic malformation was investigated. The assumed breeding time between the end of February and the end of March has the difference about a month because of a habitat and it takes about 2 or 3 weeks from laying eggs to hatching. The length of each egg bag and the number of embryos were very varied in each area. It is due to geographical variation. Among egg bags in total study area, only 406 of egg bags(17.70% of total egg bags) developed all of embryos to normal larvae, and 78.49% of total embryos were normally developed. The patterns of spontaneous embryonic malformation were 26 species from A to Z and the abnormal patterns in individual were 8 species and above. the geographical differences about the abnormal pattern were identified and 11 habitats categorized 4 groups. The most frequent abnormality in Gyeongsangnam-do area is the dysplasia of external gill. The caudal dysplasia, abdominal blister and dysplasia of fin were also frequently observed. Individuals showing severe external defect were histologically studied and they showed retinal hypo-pigmentation, thyroid carcinoma, somatic muscular dysplasia, degeneration of cephalic neuron and various organ dysplasia. Benomyl and carbendazim were treated by 10pM$^{\sim}$10uM and BIC was treated by 1$^{\sim}$40ppm to know the effect of toxicity about toxic substance of salamander. After benomyl was treated, a survival rate was sharply dropped from 2 to 8 days. $LC_{100}$ identified in $1{\mu}M$, $LC_{50}$ identified between 100nM and $1{\mu}M$. $EC_{50}$ was assumed between 10nM and 100nM. The prevalent external malformation was abdomen swelled abnormally and histo-pathological effects were abdomen, neural tube and lens hernia. This suggests that benomyl is the toxicitic substance which inhibits the development of digestive system and nervous system. The result of treated carbendazim was similar to that of the treated benomyl. The survival rate is sharply dropped between 2 and 6 days. $LC_{100}$ was identified $1{\mu}M$ and $LC_{50}$ was identified between 10nM and 100nM. This shows that cabendazim has stronger lethal toxicity than benomyl. Ventral blister, eye dysplasia and cephalic dysplasia in the individual of external malformation mean that cabendazim affected nervous system much more than benomyl. Because the toxicity of BIC affected less in the beginning but affected more in the near hatching period, the period causing toxicity is somewhat different. $LC_{100}$ identified near 40ppm and $LC_{50}$ identified near 25ppm. The external defect shows mainly ventral blister and histo-pathological results show intestinal deformities. This result suggests the BIC inhibited strongly the development of digestive system. These abnormal developments may be caused by antimitotic action, inhibition of tubulin complex, destruction of microtubule, inhibitions of neurulation and closing of neural fold, and by the inhibition of movement of neural crest cells of benomyl. These abnormal developments may be caused by the rupture of epithelium, the loss of microtubule, the reduction of spindle size, the inhibition of spindle assembly formation, the destruction of spindle poles of carbendazim. These abnormal developments may be caused cytotoxicity by inhibition of the synthesis of a number of macromolecules and similar reaction the inhibition of benomyl.

• Resources Recycling
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• v.26 no.6
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• pp.29-37
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• 2017

Nuclear fuel cladding tube is fabricated by pilgering and annealing process. In order to remove impurity and oxygen layer on the surface, pickling process is carried out. When Zirconium(Zr) is dissolved and saturated in acid solution during the pickling process, all the waste acid including Zr is disposed. Therefore, $BaF_2$ is added into the waste acid to extract Zr and $Ba_2ZrF_8$ is subsequently formed. To recycle Zr by electrowinning process, $Ba_2ZrF_8$ is used as electrolyte, but it has high melting point ($1053^{\circ}C$). $ZrF_4$ should be added into $Ba_2ZrF_8$ to decrease the melting point. In this paper, it was investigated that $Ba_2ZrF_8$ was separated to $BaF_2$ and $ZrF_4$ by vacuum distillation. Firstly, $BaF_2$ with different particle size ($1{\mu}m$, $35{\mu}m$, $110{\mu}m$) was added into the waste acid and the respective precipitation property was estimated. $BaF_2$ obtained by vacuum distillation was shattered by ball-milling with different time. The precipitation efficiency was compared with $1{\mu}m$ of ${BaF_2}^{\prime}s$ one, which was not used as precipitation agent.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.3
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• pp.135-145
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• 2019

Analysis of a long cycle or a trend of time series data based on a long-term observation would require comparability between data observed in the past and the present. In the present study, we proposed an approach to ensure the compatibility among the instruments used for the long-term observation, which would allow to secure continuity of the data. An open-path gas analyzer (Model LI-7500, LI-COR, Inc., USA) has been used for eddy covariance flux measurement in the Gwangneung deciduous forest for more than 10 years. The open-path gas analyzer was replaced by an enclosed-path gas analyzer (Model EC155, Campbell Scientific, Inc., USA) in July 2015. Before completely replacing the gas analyzer, the carbon dioxide ($CO_2$) and latent heat fluxes were collected using both gas analyzers simultaneously during a five-month period from August to December in 2015. It was found that the $CO_2$ fluxes were not significantly different between the gas analyzers under the condition that the daily mean temperature was higher than $0^{\circ}C$. However, the $CO_2$ flux measured by the open-path gas analyzer was negatively biased (from positive sign, i.e., carbon source, to 0 or negative sign, i.e., carbon neutral or sink) due to the instrument surface heating under the condition that the daily mean temperature was lower than $0^{\circ}C$. Despite applying the frequency response correction associated with tube attenuation of water vapor, the latent heat flux measured by the enclosed-path gas analyzer was on average 9% smaller than that measured by the open-path gas analyzer, which resulted in >20% difference of the sums over the study period. These results indicated that application of the additional air density correction would be needed due to the instrument heat and analysis of the long-term observational flux data would be facilitated by understanding the underestimation tendency of latent heat flux measurements by an enclosed-path gas analyzer.

• Applied Biological Chemistry
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• v.10
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• pp.15-21
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• 1968

In order to fractionate the rice protein employing paper electrophoresis, 9 subjects of Korean rice and one Indica type, Pin Galw 50 were examined, the results were as follows. 1. Polished rice protein was separated into albumin, globulin, prolamine, and oryzenin. The amount of these fractions was determined by Kjeldahl method showing respectively 0.26%, 0.65%, 0.41%, and 5.01% in average. Albumin was extracted with deionized water, globulin with 10% NaCl, prolamine with 70% ethanol, and oryzenin with 0.05N-NaOH. 2. Albumin was extracted with deionized water and dialyzed by a cellophan tube. The supernatant was submitted to paper electrophoresis using phosphate buffer (pH 7.6, ${\mu}$ 0.18). Albumin was identified as monocomponent in all of 10 varieties under study. Globulin was extracted and dialyzed to remove the albumin. The precipitates were resolved in 10% saline solution and examined by paper electrophoresis. The globulin consists of two components in phosphate buffer(pH 7.6, ${\mu}$ 0.18) Any subject, regardless the origin, appears to contain globulin I and globulin II. Prolamine was extracted with 70% ethanol, dialayzed against deionized water, resolved with ethanol, and analyzed by Paper electrophoresis. It was proved as one component in the 70% alcoholic buffer(pH 9.0, ${\mu}$=0.0095). On the contrary, paper electrophoresis with oryzenin demonstrated two or three components in Sorensen's buffer(pH 13.0, ${\mu}$ 0.11). Yookoo 132, Dungpan 5, Kwansan, and Jaekun contain oryzenin I, oryzenin II, and oryzenin III. On the other hand, Paldal, Jinheung, Sukwang, Eunbangzu, Damakum, and Pin Galw 56 contain only oryzenin II, and oryzenin III. On the basis of these analyses a discussion of the differences between the protein fractions of 10 varieties was presented. 3. Globulin I varied from 0.22% to 0.46% (aver. 0.35%) in the amount, globulin II from 0.21 to 0.44%(aver. 0.32%), oryzenin I from 0.17% to 0.44%(aver. 0.3%), oryzenin II from 1.59% to 2.88%(aver. 2.23%), and oryzenin III from 2.02% to 3.57%(aver. 2.66%).

• Advances in pediatric surgery
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• v.1 no.2
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• pp.149-161
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• 1995

The first national survey on esophageal atresia and tracheoesophageal fistula was conducted to access the current status of its incidence, clinical manifestation, preoperative diagnosis and management, type of its anomaly, associated anomalies, and surgical results and course. The 43 members of the Korea Association of Pediatric Surgeons received questionnaires and registration forms to be filled out on each patient who were born during the three years from January 1, 1992 through December 31, 1994. Questionnaires composed of six broad areas which include 1) preoperative diagnosis and management, 2) surgical technic, 3) long gap, 4) postoperative management, and 5) complications and courses. A total of 148 cases was returned by 28 members working at 23 institutions and 27 members returned questionnaires. We obtained the following results by analysis of the 148 cases of tracheoesophageal anomalies. The incidence of tracheoesophageal anomaly was about 1/10,000-11,000 in 1994, which is one third of that of anorectal malformations in Korea and the distribution of the patients was almost proportionate to the size of each province. Both sexes are about equally affected. Majority of the members make diagnosis of tracheoesophageal anomaly by taking a simple infantogram with a radiopaque tube in upper pouch and a little under half(46%) prefers to perform echocardiography as a part of preoperative management to identify congenital heart disease and lateralize the aorta. Esophageal atresia with distal TEF(87.5%) was by far the most common and there were pure esophageal atresia(5.6%), H-type TEF(2.1%), and so on. About half(49%) of the patients had one or more associated anomalies in addition to tracheoesophageal anomalies. Congenital heart disease was associated in 46 cases(31%), anorectral malfomations in 19 cases(13%), musculoskeletal anomalies in 15 cases(10%), genitourinary anomalies in 10 cases(7%) and gastrointestinal anomalies in 7 cases(5%). Postoperatively, parenteral nutrition and assisted ventilation were given in 66% and 52% of patients respectively. Ninety three(74%) of 126 cases who underwent sugical procedure, experienced one or more complications such as respiratory complication(65%), leak(22%), stricture(21%) and so on. The survival rates related to the Waterston risk categories were 90.2% in group A, 71.4-75% in $B_1$, $B_2$, and $C_1$, groups, and 28% in group $C_2$, and the overall survival rate was 71.4%. Thirty six(28.6%) of 126 cases died of pneumonia/sepsis(12 cases), respiratory failure(12 cases), and congenital heart disease(4 cases). With short term follow-up, 69% of patients have been excellent whereas remainders of the cases have suffered from some sort of morbidity related to gastroesophageal reflux, recurrent respiratory infection, and esophageal stricture.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.121-127
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• 1985

This study was designed to gain practical data on the use of soil conditioners for more efficient water managements and to establish the optimum levels of structural properties for soil conditioning. A sandy loam and a silt loam soil were each treated with two different soil conditioners, hydrophobic Bitumen or hydrophilic Uresol. The perspex tube 34 cm long were packed homogeneously with air dried soil up to 2 cm below the top, then covered over 2 cm of treated or untreated aggregates. The infiltration rate into the soil columns was measured under simulated rainfall condition. The evaporation study was carried out in the wind tunnel, and the changes of soil moisture distribution of the columns following and during the evaporation were determined by a gamma ray scanner. The infiltration rate of water into the soil column was increased to 18.7-50.8% by the Uresol treatment but it was decreased to less than 25% of control by the Bitumen treatment. Evaporation was decreased to 22.0-68.1% by the Bitumen treatment and to 38.7-68.4% by the Uresol treatment. The water use efficiency of Uresol treated column was increased to more than twice as much as that of untreated soil. Aggregate stability and wetting angle were related to water infiltration and evaporation. A positive and highly significant logarismic relationship was found between the infiltration rate and stability index-wetting angle, evaporation rate and instability index-wetting angle. It was considered that the structural stability is more important than wetting angle. This is true because the structural stability is always positively correlated to water saving, however wettability is positively correlated to the infiltration, and negatively correlated to water saving during the evaporation.

• Journal of Chest Surgery
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• v.29 no.4
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• pp.373-380
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• 1996

Prevention of thromboembolism is the most important task in the development of bioconpatible small caliber artificial vascular graft. In normal vessels, vascular endothelial cells maintain homeosatsis by secreting numerous factors. The aim of this study is to develope a method which Improves biocompatibility of small caliver polyurethane graft using endothelial cell culture technique, and ev luate the efTectiveness of extracelluar matrix for endothelization which was produced by cultured fibroblast. Methods ; Multiporous polyurethane tube of 3 mm diameter, 0.3 mm thickness was manufactured for vascular graft. Three mongrel dogs were intubated and internal jugular veins removed. Extracelluar matrix produced by cultured flbrobast which was obtained from dog's internal jugular vein were coated to the polyurethane graft. Then, endothelial cells extracted from Jugular vein were cultured and fixed on the extracelluar matrix layer of vascular graft. Endothelial cell coated vascular grafts were implanted to the carotid arteries of experimental dogs as interposed autograft. Implanted grafts were removed after 3 and 6 weeks. As a control, PTFE graft was interposed on carotid artery. These experiments demonstrated that extracelluar matrix produced by fibroblast can afford a base for endothelial cell linings of polyurethane graft. Although thrombosis were developed on autografted en othelial cell coated graft, 33% opening was noticed, and showed less adhesion to adjacent tissue layer. These findings suggest that fiboblast produced extracelluar matrix which can be used for edothelial cell lining vascular graft, and by improving the cultured endothelial cell function, there will be a new modality for reducing thrombosis on small vascular graft.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.5-5
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• 2011

The research and development of hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV) and electric vehicle (EV) are intensified due to the energy crisis and environmental concerns. In order to meet the challenging requirements of powering HEV, PHEV and EV, the current lithium battery technology needs to be significantly improved in terms of the cost, safety, power and energy density, as well as the calendar and cycle life. One new technology being developed is the utilization of composite cathode by mixing two different types of insertion compounds [e.g., spinel $LiMn_2O_4$ and layered $LiMO_2$ (M=Ni, Co, and Mn)]. Recently, some studies on mixing two different types of cathode materials to make a composite cathode have been reported, which were aimed at reducing cost and improving self-discharge. Numata et al. reported that when stored in a sealed can together with electrolyte at $80^{\circ}C$ for 10 days, the concentrations of both HF and $Mn^{2+}$ were lower in the can containing $LiMn_2O_4$ blended with $LiNi_{0.8}Co_{0.2}O_2$ than that containing $LiMn_2O_4$ only. That reports clearly showed that this blending technique can prevent the decline in capacity caused by cycling or storage at elevated temperatures. However, not much work has been reported on the charge-discharge characteristics and related structural phase transitions for these composite cathodes. In this presentation, we will report our in situ x-ray diffraction studies on this mixed composite cathode material during charge-discharge cycling. The mixed cathodes were incorporated into in situ XRD cells with a Li foil anode, a Celgard separator, and a 1M $LiPF_6$ electrolyte in a 1 : 1 EC : DMC solvent (LP 30 from EM Industries, Inc.). For in situ XRD cell, Mylar windows were used as has been described in detail elsewhere. All of these in situ XRD spectra were collected on beam line X18A at National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory using two different detectors. One is a conventional scintillation detector with data collection at 0.02 degree in two theta angle for each step. The other is a wide angle position sensitive detector (PSD). The wavelengths used were 1.1950 ${\AA}$ for the scintillation detector and 0.9999 A for the PSD. The newly installed PSD at beam line X18A of NSLS can collect XRD patterns as short as a few minutes covering $90^{\circ}$ of two theta angles simultaneously with good signal to noise ratio. It significantly reduced the data collection time for each scan, giving us a great advantage in studying the phase transition in real time. The two theta angles of all the XRD spectra presented in this paper have been recalculated and converted to corresponding angles for ${\lambda}=1.54\;{\AA}$, which is the wavelength of conventional x-ray tube source with Cu-$k{\alpha}$ radiation, for easy comparison with data in other literatures. The structural changes of the composite cathode made by mixing spinel $LiMn_2O_4$ and layered $Li-Ni_{1/3}Co_{1/3}Mn_{1/3}O_2$ in 1 : 1 wt% in both Li-half and Li-ion cells during charge/discharge are studied by in situ XRD. During the first charge up to ~5.2 V vs. $Li/Li^+$, the in situ XRD spectra for the composite cathode in the Li-half cell track the structural changes of each component. At the early stage of charge, the lithium extraction takes place in the $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ component only. When the cell voltage reaches at ~4.0 V vs. $Li/Li^+$, lithium extraction from the spinel $LiMn_2O_4$ component starts and becomes the major contributor for the cell capacity due to the higher rate capability of $LiMn_2O_4$. When the voltage passed 4.3 V, the major structural changes are from the $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ component, while the $LiMn_2O_4$ component is almost unchanged. In the Li-ion cell using a MCMB anode and a composite cathode cycled between 2.5 V and 4.2 V, the structural changes are dominated by the spinel $LiMn_2O_4$ component, with much less changes in the layered $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ component, comparing with the Li-half cell results. These results give us valuable information about the structural changes relating to the contributions of each individual component to the cell capacity at certain charge/discharge state, which are helpful in designing and optimizing the composite cathode using spinel- and layered-type materials for Li-ion battery research. More detailed discussion will be presented at the meeting.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.704-710
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• 2012

The lower portion of sloping paddy fields normally contains excessive moisture and the higher water table caused by the inflow of ground water from the upper part of the field resulting in non-uniform water content distribution. Four drainage methods namely Open Ditch, Vinyl Barrier, Pipe Drainage and Tube Bundle for multiple land use were installed within 1-m position from the lower edge of the upper embankment of sloping alluvial paddy fields. This study was conducted to evaluate soil physical characteristics by drainage improvement in poorly drained sloping paddy field. The results showed that subsurface drainage by Pipe Drainage improves the productivity of poorly drained soils by lowering the water table and improving root zone soil layer condition. In an Pipe drainage plot, soil moisture drained faster as compared to the other drainage methods. Infiltration rate showed high tendency to Piper Drainage method about $20.87mm\;hr^{-1}$ than in Open Ditch method $0.15mm\;hr^{-1}$. And Similarly soil water and degree of hardness and shear strength phase of soil profile showed a tendency to decrease. From the above results, we found that when an subsurface drainage was established with at 1m position from the lower edge paddy levee of the upper field in sloping poorly drained paddy fields Pipe Drainage was the most effective drainage system for multiple land use.