• Journal of Korean Society for Atmospheric Environment
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• v.29 no.1
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• pp.74-85
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• 2013

Since the underground transportation system is a closed environment, indoor air quality problems may seriously affect many passengers' health. The purpose of this study was to understand $PM_{10}$ characteristics in the underground air environment and further to quantitatively estimate $PM_{10}$ source contributions in a Seoul Metropolitan subway station. The $PM_{10}$ was intensively collected on various filters with $PM_{10}$ aerosol samplers to obtain sufficient samples for its chemical analysis. Sampling was carried out in the M station on the Line-4 from April 21 to 28, July 13 to 21, and October 11 to 19 in the year of 2010 and January 11 to 17 in the year of 2011. The aerosol filter samples were then analyzed for metals, water soluble ions, and carbon components. The 29 chemical species (OC1, OC2, OC3, OC4, CC, PC, EC, Ag, Al, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Si, Ti, V, Zn, $Cl^-$, $NO_3{^-}$, $SO_4{^{2-}}$, $Na^+$, $NH_4{^+}$, $K^+$, $Mg^{2+}$, $Ca^{2+}$) were analyzed by using ICP-AES, IC, and TOR after proper pretreatments of each sample filter. Based on the chemical information, positive matrix factorization (PMF) model was applied to identify the $PM_{10}$ sources and then six sources such as biomass burning, outdoor, vehicle, soil and road dust, secondary aerosol, ferrous, and brakewear related source were classified. The contributions rate of their sources in tunnel are 4.0%, 5.8%, 1.6%, 17.9%, 13.8% and 56.9% in order.

• Journal of Bio-Environment Control
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• v.12 no.4
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• pp.240-244
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• 2003

The purpose of this study was to investigate a proper $Ca^{2+}\;:\;K^+$ ratio in nutrient solution to produce marjoram and oregano by hydroponics. Two herbs were grown for 40 days with the $Ca^{2+}\;:\;K^+$ ratio of 3.5;13, 4.5:11(standard herb's nutrient solution), 5.5:9 and 6.5:7mM${\cdot}L^{-1}$ of herb's nutrient solution developed by European Vegetable R &D Center, Belgium. The ratio of 5.5:9, and 6.5:7 mM${\cdot}L^{-1}$ showed better results in growth of marjoram than other treatments. Vitamin C contents and amounts of esential oil were the highest in the ratio of 5.5:9 and 6.5:7, respectively. Inoregano, the growth and vitamin C contents were the highest in the ratio of 5.5:9 and 6.5:7 mM${\cdot}L^{-1}$, respectively. The content (%) and amount (mg/plant) of essential oil were the highest in the ratio of 6.5:7mM${\cdot}L^{-1}$. These results indicated that 5.5:9 and 6.5:7 mM${\cdot}L^{-1}$were proper $Ca^{2+}\;:\;K^+$ ratio of nutrient solution of marjoram and oregano, respectively, by hydropoinics.

• Korean Journal of Materials Research
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• v.23 no.4
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• pp.240-245
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• 2013

Electrochemical surface treatment is commonly used to form a thin, rough, and porous oxidation layer on the surface of titanium. The purpose of this study was to investigate the formation of nanotubular titanium oxide arrays during short anodization processing. The specimen used in this study was 99.9% pure cp-Ti (ASTM Grade II) in the form of a disc with diameter of 15 mm and a thickness of 1 mm. A DC power supplier was used with the anodizing apparatus, and the titanium specimen and the platinum plate ($3mm{\times}4mm{\times}0.1mm$) were connected to an anode and cathode, respectively. The progressive formation of $TiO_2$ nanotubes was observed with FE-SEM (Field Emission Scanning Electron Microscopy). Highly ordered $TiO_2$ nanotubes were formed at a potential of 20 V in a solution of 1M $H_3PO_4$ + 1.5 wt.% HF for 10 minutes, corresponding with steady state processing. The diameters and the closed ends of $TiO_2$ nanotubes measured at a value of 50 cumulative percent were 100 nm and 120 nm, respectively. The $TiO_2$ nanotubes had lengths of 500 nm. As the anodization processing reached 10 minutes, the frequency distribution for the diameters and the closed ends of the $TiO_2$ nanotubes was gradually reduced. Short anodization processing for $TiO_2$ nanotubes of within 10 minutes was established.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.281-285
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• 2002

Whole plant cultures of Centella asiatica (L.) Urban in vitro were established and the effects of basal media, some macro elements and sucrose concentration on productivity of triterpene glycosides (madecassoside and asiaticoside: M$\varepsilon$A) were investigated. Among the media (MS, B5, RCM) tested, MS and 0.5 RCM medium were the best for plant growth and M$\varepsilon$A production, respectively. However, taking into account the M$\varepsilon$A productivity, B5 medium was superior (M$\varepsilon$A: 14.28 mg/g dry wt.). Major macronutrients of B5 medium adjusted with the concentration of 25 mM KNO$_3$,1 mM NaH$_2$PO$_4$, 1 mM CaCl$_2$ and 1~10 mM MgSO$_4$, caused elevated or optimized levels of M$\varepsilon$A. On sucrose concentration, the highest yields of M$\varepsilon$A were obtained from 6% sucrose.

• Food Science and Preservation
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• v.23 no.1
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• pp.89-96
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• 2016

The purpose of this study was to investigate the chemical composition of the freeze-dried stems and fruit of the cactus Cheonnyuncho. The analysis showed that powdered stems have the highest fat content (1.91%) and the powdered fruits have he highest protein content (2.62%). The K content of the fruits higher than that of the stems, while the Ca, Mg, Na and P contents of the stems were higher than those of the fruits. Both the stems and fruits powders contained high levels of the amino acids glutamic acid and aspartic acid. The free sugars such as sucrose, fructose, and glucose were detected in both the stems and fruits. The 75% ethanol (EtOH) extract showed a relatively high antioxidative activity compared to those of the water and 75% methanol (MeOH) extracts. Furthermore, the 75% EtOH extract of the stem powder exhibited a total polyphenol content of 3.60 g/100 g, and a total flavonoid content of 2.00 g/100 g. The antioxidant activities of the stem and fruit powder extracts, measured in DPPH radical scavenging experiments, were higher than that of the control group.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.8 no.1
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• pp.50-61
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• 2001

With the improvement of current medicine, the number of the chronicly ill children are increasing. The illness of the child drives all of the family to despair. especially it is a burden on the mother who takes care of the ill child. She's faced with many emergencies and feels powerless. The home care for a child is for finding a child's problems early and mediating them. The purpose of this study was to investigate the mother's reaction following their chronicly ill child's discharge and to investigate the supporting needs for caring for an ill child. The subjects of this study were mothers with a chronicly ill child being discharged from a general hospital in Seoul and the data was collected from July 20 to September 30. Data was collected by using questionnaires which were developed by the researcher. (The questionnaires were composed of the average 5 points - Likert's method). The Mother's reaction means that the higher the score, the more negative the mother's thoughts about discharge are. Supporting need for caring for ill an child means that the higher the score, the higher the demand of nursing is. The statistical analysis used the SPSS program for t-test. ANOVA, and Pearson Correlation. The results of this study were as follows: 1. The mother's reaction scores following discharge were the lowest. 19 and the highest 72 so that the total average was 43.15. The answer, 'I worry that my baby will be troubled with illness again after discharge gained the high points (3.94 of 5 points). The answer. 'The discharge of my baby makes me gloomy' gained 2.05-it was the lowest points. Their were significant differences according to religion (p=.006). salary (p=.050). the burden of the medical fee (p = .005) and caregiver (p=.027). 2. Supporting Need for caring for ill an child was the lowest 15 and the highest 67. the total average was 47.87. The answer. 'I'd be glad to get a person whom I could always get counsel about the health of my baby with' scored the high point (average 4.04 of 5). The answer. 'Caring for my baby at home makes me exhausted' gained the lowest point. 2.49. Their were significant differences according to religion (p=.019) and diagnosis (p=.019). 3. The relationship between the reaction of the mother and supporting need for caring for an ill child was a positive correlation (r=0.585). In conclusion. this study revealed that mothers weren't positive about their chronicly ill child's discharge and they wanted to get support for caring for an ill child. Through this study. I proposed that the program to support the chronicly ill child at home and home care by continuous counselling after discharge should be develop.

• Korean Journal of Environmental Agriculture
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• v.7 no.2
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• pp.111-116
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• 1988

The aquatic plants were cultivated in pots containing pig waste water, adjusted to three levels of $NH_4-N$ concentration 50, 100 and 200ppm. The aquatic plants were Eichhornia crassipes solms-laub, Monochoria korsakowii Regel et maack, Zizania caduciflora, Typha orientalis, Acorus asiaticus, Cyperus exaltaus, Colocasia antiquorum var. Yield, content and amount of nitrogen and phosphorus absorped by plants, and growth status were investigated. The results obtained are as follows. 1. The content and removal amount of nitrogen and phosphrus by plants were the highest in Eichhornia crassipes solms-laub. 2. Yield of dry matter in plants in 100ppm $NH_4-N$ was in the order of Eichhornia crassipes solms-laub>Zizania caduciflora>Typha orientalis>Monochoria korsakowii Regel et maack>Acorus asiaticus. 3. The removal amount of nitrogen by plants in the 100ppm $NH_4-N$ was in the order of Eichhornia crassipes solms-laub>Zizania caduciflora>Monochoria korsakowii Regel et maack>Typha orientalis>Acorus asiaticus>Colocasia antiquorum var>Cyperus exaltatus. Removal amount of phosphorus was in the order of Eichhornia cras sipes solms-laub>Monochoria korsakowii Regel et maack>Zizania caducilora>Typha orientalis>Acorus asiaticus> Cyperus exaltatus>Colocasia antiquorum var. 4. Concentration causing growth damage was 200ppm of $NH_4-N$ in Eichhornia crassipes solms-laub, Zizania caduciflora and Typha orientalis and 100ppm in Monochoria korsakowii Regel et maack and Acorus asiaticus. 5. Nitrogen content was the highest in leaf and phosphorus content was the highest in float of the water hyacinth. 6. The number of panicles of the water hyacinth increased by 752 pieces and dry matters were about 5,000kg/l0a during one year.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.645-654
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• 1995

Porphyromonas endodontalis is a black-pigmented anaerobic Gram negative rod which is associated with endodontal infections. It has been isolated from infected dental root canals and submucous abscesses of endodontal origin. DNA probe is an available alternative, offering the direct detection of a specific microorganism. Nucleic-acid probes can be off different types: whole different: whole-genomic, cloned or oligonucleotide probes. Wholegenomic probes are the most sensitive because the entire genome is used for possible hybridization sites. However, as genetically similar species of bacteria are likely to be present in specimences, cross-reactions need to be considered. Cloned probes are isolated sequences of DNA that do not show cross-reactivity and are produced in quantity by cloning in a plasmid vector. Cloned probes can approach the sensitivity found with whole-genomic probes while avoiding known cross-reacting species. Porphyromonas endodontalis ATCC 35406 (serotype $O_1K_1$) was selected in this experiment to develop specific cloned DNA probes. EcoR I-digested genomic DNA fragments of P. endodontalis ATCC 35406 were cloned into pUC18 plasmid vector. From the E. coli transformed with the recombinant plasmid 4 clones were selected to be tested as specific DNA probes. Restriction-digested whole-genomic DNAs prepared from P. gingivalis 38(serotype a), W50(serotype b), A7A1-28(serotype C), P. intermedia 9336(serotype b), G8-9K-3(serotype C), P. endodontalis ATCC 35406(serotype $O_1K_1$), A. a Y4(serotype b), 75(serotype a), 67(serotype c), were each seperated on agarose gel electrophoresis, blotted on nylon membranes, and were hybridized with digoxigenin-dUTP labeled probe. The results were as follows: 1. Three clones of 1.6kb(probe e), 1.6kb(probe f), and 0.9kb(probe h) in size, were obtained. These clones were identified to be a part of the genomic DNA of P. endodontalis ATCC 35406 judging from their specific hybridization to the genomic DNA fragments of their own size on Southern blot. 2. The clones of 4.9kb(probe i) was identified to be a part of the genomic DNA of P. endodontalis ATCC 35406. but not to specific for itself. It was hybridized to P. gingivalis A7A1-28, P. intermedia G89K-3.

• International Journal of Computer Science & Network Security
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• v.21 no.7
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• pp.17-34
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• 2021

This study aimed to examine the Factor Structure of the teacher satisfaction scale (TSS) with distance education during the Covid-19 pandemic, as well as affirming the (Factorial Invariance) according to gender variable. It also aimed at identifying the degree of satisfaction according to some demographic variables of the sample. The study population consisted of all teachers in public education and faculty members in higher education in the Kingdom of Saudi Arabia. The (TSS) was applied to a random sample representing the study population consisting of (2399) respondents. The results of the study showed that the scale consists of five main factors, with a reliability value of (0.94). The scale also showed a high degree of construct validity through fit indices of the confirmatory factor analysis. The results have shown a gradual consistency of the measure's invariance that reaches the third level (Scalar-invariance) of the Measurement Invariance across the gender variable. The results also showed that the average response of the study sample on the scale reached (3.74) with a degree of satisfaction, as there are no statistically significant differences between the averages of the study sample responses with respect to the gender variable. While there were statistically significant differences in the averages with respect to the variable of the educational level in favor of the middle school and statistically significant differences in the averages attributed to the years of experience variable in favor of those whose experience is less than (5) years.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.219-230
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• 2021

BACKGROUND: Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change. METHODS AND RESULTS: Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃). CONCLUSION: This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.