• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.342-356
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• 1992

Kinetic studies using stirred-flow methods were conducted with the Luisiana soil at three pH levels(pH 5, 6.5, and 8) and three temperature levels(10, 25, and $40^{\circ}C$) to explore effects on the rate of silica retention and release and to find out reaction mechanisms. In this study the maximum silica retention could not be obtained for long enough experimental time. The silica sorption isorption was C type fitted well to Freundlich equation. The pH of the soil suspension increased by the silica release process at low pH treatments(pH 5 and 6.5), while decreased at high pH treatment(pH 8). From the above findings It can be deduced that the mechanism of silica retention is a multilayer forming process to change the ligand form depending on pH condition. In the proposed mechanism the sorbed silica provide new binding sites for additional sorption of silica, while the activation energy for the formation of subsequent layers increases correspondingly. The silica retention and release process were well described by first-order and parabolic diffusion equation. However, clear interpretation for silica sorption mechanism using these equations could not be made. The validity of the fraction term (Fa and Fd) included in first-order and parabolic diffusion equation requires further examinations because the temperature effect on apparent rate constant shows no constant trends among temperature treatments, while there was a good trend in Elovich and modified Freundlich equation where the fraction term was not included.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.1
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• pp.8-15
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• 2021

TiO2 has been used in various fields such as solar cells, dental implants, and photocatalysis, because it has high physical and chemical stability and is harmless to the body. TiO2 nanofibers which have a large specific surface area also show a good reactivity in bio-friendly products and excellent photocatalysis in air and water purification. To fabricate TiO2 nanofibers, an electrospinning method was used. To observe the diameter of TiO2 nanofibers with fabrication variables, the fabrication variables was divided into precursor composition variables and process variables and microstructure was analyzed. The concentrations of PVP (Polyvinylpyrrolidone) and TTIP (Titanium(IV) isopropoxide) were selected as precursor composition variables, and inflow velocity and voltage were also selected as process variables. Microstructure and crystal structure of TiO2 nanofibers were analyzed using FE-SEM (Field emission scanning electron microscope) and XRD (X-ray diffraction), respectively. As-spun TiO2 nanofibers with an average diameter of about 0.27 ㎛ to 1.31 ㎛ were transformed to anatase TiO2 nanofibers with an average diameter of about 0.22 ㎛ to 0.78 ㎛ after heat treatment of 3 hours at 450℃. Anatase TiO2 nanofibers with an average diameter of 0.22 ㎛ can be expected to improve the photocatalytic properties by increasing the specific surface area. To change the average diameter of TiO2 nanofibers, the control of precursor composition variables such as concentrations of PVP and TTIP is more efficient than the control of electrospinning process variables such as inflow velocity and voltage.

• Analytical Science and Technology
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• v.16 no.4
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• pp.292-298
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• 2003

In this study, the photooxidation and ozonation of humic acid (HA) in aqueous solution were conducted and the treated HA samples at different reaction time were analyzed using ultrafiltration techniques to evaluate the change of their molecular size distributions with its DOC removal. Molecular size distribution of untreated HA showed 41.5% in higher molecular size fractions (>30,000 daltons) and 15.2% in much smaller molecular size fraction (<500 daltons). As UV irradiation time was increased, it was observed that the degradation of the large molecules of the fraction of >30,000 daltons into much smaller molecules was increased. In UV system, the HA molecules of the fraction of <500 daltons became significantly more and its percentage was increased from 35.3% (UV only irradiation) to 58.9% ($UV/TiO_2$) and 87.8% ($UV/H_2O_2$) in the presence of the photocatalysis. Otherwise, ozonation of HA produced mainly the fraction of medium molecular size ranging from 3,000 to 30,000 daltons with much lower portion (<~7%) in the fraction of <500 daltons. In ozone only system, the fraction of 30,000~10,000 daltons occupied in 41.5% at 60 min of ozonation time. In $O_3/H_2O_2$ system, the fraction of 30,000~10,000 daltons and 10,000~3,000 daltons occupied in 38.9% and 36.2% respectively. Based on these results, we suggested applicable treatment process which could be combined with $UV/H_2O_2$, $UV/TiO_2$ and $O_3$, $O_3/H_2O_2$ system for more effective removal of humic acid in water treatment.

• Journal of Oral Medicine and Pain
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• v.30 no.3
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• pp.301-317
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• 2005

The number of patients with tongue carcinoma is increasing rapidly among young individuals in many parts of the world. Oral carcinoma progresses from hyperplastic lesion through dysplasia to invasive carcinoma and the concept of "field cancerization" with molecular alteration has been suggested for oral cavity carcinogenesis. Significant improvement in treatment and prognosis will depend on more detailed understanding of the multi-step process leading to cancer development. To induce tongue carcinoma in rat by 4-NQO, each drinking water was made to 10 ppm, 25 ppm, 50 ppm and control (only D.W. without 4-NQO). Specimens were classified into 4 groups such as control, I (mild & moderate dysplasia), II (severe dysplasia and carcinoma in situ), III (carcinoma). The mRNA expressions of Bcl-2 family were evaluated by RT-PCR technique. For anti-apoptotic Bcl-2 family, mRNA expression of Bcl-w was down-regulated in all stages of tongue carcinogenesis model. However, mRNA expression of Bcl-2 was up-regulated. For pro-apoptotic Bcl-2 family, all members were down-regulated in all stages of tongue carcinogenesis model except for Bad mRNA in group III. In terms of BH3 only protein, mRNA expressions of Bok and Mcl-1 were down regulated in all stages of specimen, but Bmf in group II and BBC3 in group III were up-regulated. Our current findings demonstrated the involvements of mRNA expression of Bcl-2 family in multi-step tongue carcinogensis. This highlights the necessity for continued efforts to discover suitable biomakers (Bcl-2 family) for early diagnosis of the disease, and to understand its pathogenesis as a first step in improving methods of treatment. The discovery of these potential biomarkers and molecular targets for cancer diagnostics and therapeutics has the potential to significantly change the clinical approach and outcome of the disease.

• Asian Journal of Turfgrass Science
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• v.19 no.2
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• pp.115-123
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• 2005

The effect of sodium hypochlorite treatment on the germination of cattail (Typha spp.) seeds was investigated in growth chambers maintained on a 14-h photoperiod with various temperatures and light intensities. Germination rates of seeds were, in general, enhanced by the increase of light intensity and temperature regardless of cattail species. Seeds of T. oreientalis had 4.3, 13.0 and $7.3\%$ germination at temperatures of 20, 25 and $30^{circ}$C, respectively, under light intensity of 7.5${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. T. angustata showed higher germination rate, thus, 10.7, 22.7 and $50.7\%$ under same temperature and light environment. Under high light intensity of 79.5${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, the germination rates of T. oreintalis and T angustata were $78.3\%$ and $88.7\%$ at $30^{circ}$C, respectively. Scarification of seeds with NaOC1 ($4\%$, available chlorine) increased germination rate in both species, especially even at low temperature of $20^{circ}$C. Germination speed was also enhanced by NaOC1 treatment. High light intensity further increased the germination rate. When NaOC1 treated seeds were sowed on the soil surface in plastic house, the seedling emergence was nearly $100\%$. Untreated seeds of T. oreintalis and T. angustara showed 40 and $50\%$, respectively, in germination under same condition. However, when the depth of soil covering was over 1.0 cm, seedling emergence was retarded more than 1 month. On the process of seedling development, emergence of mesocoty1 occurred firstly and after than primary root and first leaf were developed on the end of elongated mesocotyl. These results suggest that the promotion of seed germination by NaOC1 pretreament may be induced from the increase of light absorptivity as well as water permeability through scarifying and bleaching the seed coat.

• Progress in Medical Physics
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• v.21 no.2
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• pp.192-200
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• 2010

Cyberknife with small field size is more difficult and complex for dosimetry compared with conventional radiotherapy due to electronic disequilibrium, steep dose gradients and spectrum change of photons and electrons. The purpose of this study demonstrate the usefulness of Geant4 as verification tool of measurement dose for delivering accurate dose by comparing measurement data using the diode detector with results by Geant4 simulation. The development of Monte Carlo Model for Cyberknife was done through the two-step process. In the first step, the treatment head was simulated and Bremsstrahlung spectrum was calculated. Secondly, percent depth dose (PDD) was calculated for six cones with different size, i.e., 5 mm, 10 mm, 20 mm, 30 mm, 50 mm and 60 mm in the model of water phantom. The relative output factor was calculated about 12 fields from 5 mm to 60 mm and then it compared with measurement data by the diode detector. The beam profiles and depth profiles were calculated about different six cones and about each depth of 1.5 cm, 10 cm and 20 cm, respectively. The results about PDD were shown the error the less than 2% which means acceptable in clinical setting. For comparison of relative output factors, the difference was less than 3% in the cones lager than 7.5 mm. However, there was the difference of 6.91% in the 5 mm cone. Although beam profiles were shown the difference less than 2% in the cones larger than 20 mm, there was the error less than 3.5% in the cones smaller than 20 mm. From results, we could demonstrate the usefulness of Geant4 as dose verification tool.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.319-325
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• 2004

The objective of the present study was to investigate the effect of processing conditions on the physical and sensory properties of pork cutlet produced from chilled pork loin (T1), the cured and massaged chilled pork loin (T2), the cured and massaged frozen pork loin (T3), frozen pork loin (T4), massaged frozen pork loin (T5). Water holding capacity (WHC) of pork cutlets were not significantly different among the treatments. In chilled pork loin, WHC of T2 were slightly higher than that of T1. T4 showed the lowest WHC among all treatment group. In meat color, CIE L$\^$*/, a$\^$*/. b$\^$*/ values in chilled pork loin were not significantly different between T1 and T2. L$\^$*/ values of T3 and T5 were higher than that of T4. a$\^$*/ values were not significantly different among the all treatments. T3 produced through the curing and massaging treatment showed the highest tenderness in shear force (p< 0.001), while force value (kg/㎤) of T4 were the highest among all treatments. Separation ratio of wheat dough from pork cutlet was highest (p.<0.001) in T4. In triangle test, T1 : T3 combination was higher than that of other pairs. No differences in acceptability of sensory evaluation were observed among T1, T2, T3, and T5 groups, while the frozen pork showed the lowest (p<0.001) acceptability. In conclusion, pork cutlets from T4 with the curing and/or massaging process showed similar acceptance than those from chilled pork loins, and this treatments may contribute to promote the consumption of frozen pork loins.

• Journal of Animal Environmental Science
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• v.14 no.2
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• pp.129-138
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• 2008

This study was carried out to investigate the operating characteristics, water balance and chemical properties of compost during the composting with pig slurry on-farm trial. The composting plant with sawdust pile filteration was done in a forced aeration inside a house and equipped with a turning machine moving on a rails. The composting pit was 4.6m wide, 53m long and the maximum height was 2m. A field scale aerobic composting facility was tested the composting efficiency of high moisture pig slurry. The sawdust materials remained 6 months. Pig slurry was added to compost pile every other day during 6 months run. The temperature in compost pile and compost house, and input and output of moisture were measured during composting process. The result are summarized as follows; 1. The temperature of compost was varied in range of at $22.4^{\circ}C{\sim}71.1^{\circ}C$. After turning, the composting temperature decreased to $50^{\circ}C{\sim}36^{\circ}C$ during $3{\sim}5$ hours, and then raised to $64.5^{\circ}C$ 2. The temperature of compost house was maintained $20^{\circ}C{\sim}30^{\circ}C$, and relative humidity was varied in range of $50{\sim}99%$. 3. BOD, CODcr and SS of leachate water was reduced 89.5%, 81.2%, 97.5%, respectively. 4. The content of heavy metal in the final compost was lower those of Korea standards. 5. The amount of effluent was 10.2%. Total evaporation during composting Period were 74.8%. The amount of slurry per $1m^3$ sawdust was $3.16m^3$ without treatment of effluent output.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.514-520
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• 2014

In this study, the production potential of alternative coagulant ($Al_2(SO_4)_3$ solution) having the identical coagulation activity with respect to the commercial coagulant was investigated. The raw material of alternative coagulant was a spent catalyst including aluminium (waste activated alumina) generated in the manufacturing process of the polymer. The alternative coagulant was produced through a series of processes: 1) intense heat and grinding, 2) chemical polymerization and substitution with $H_2SO_4$ solution, 3) dissolution and dilution and 4) settling and separation. To determine the optimal operating conditions in the lab-scale autoclave and dissolver, the content of $Al_2O_3$ in alternative coagulant was analyzed according to changes of the purity of sulfuric acid, reaction temperature, injection ratio of sulfuric acid and water in the dissolver. The results showed that the alternative coagulant having the $Al_2O_3$ content of 7~8% was produced under the optimal conditions such as $H_2SO_4$ purity of 50%, reaction temperature of $120^{\circ}C$, injection ratio of $H_2SO_4$ of 5 times and injection ratio of water of 2.3 times in dissolver. In order to evaluate the coagulation activity of the alternative coagulant, the Jar-test was conducted to the effluent in aerobic reactor. As a result, in both cases of Al/P mole of 1.5 and 2.0, the coagulation activity of the alternative coagulant was higher than that of the existing commercial coagulant. When the production costs were compared between the alternative and commercial coagulant through economic analysis, the production cost reduction of about 50% was available in the case of the alternative coagulant. In addition, it was identified that the alternative coagulant could be applied at field wastewater treatment plant without environmental problem through ecological toxicity testing.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.195-201
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• 2014

Body fluid has been studied for diverse fields like Ringer's solutions, artificial joint fluids, cell growth culture media because it plays a crucial role in controlling body temperature and acts as a solvent for diverse metabolite processes in the body and delivery media of mineral, energy source, hormone, signal and drug from and to cell via blood or lymphatic vessel by osmotic pressure or active uptake. Stratum corneum containing extracellular lipids and NMF (natural moisturizing factor) absorbs atmospheric water residing outside of cells and utilize it to hydrate inside of their own. This process is related to skin barrier function. In this study, we conducted the cell viability test with Cell Bio Fluid $Sync^{TM}$, which mimicks body fluids including amino acids, peptides, and monosaccharides to strengthen skin barrier, and the clinical skin improvement test with cosmetics containing Cell Bio Fluid $Sync^{TM}$. In the cell viability test, HaCaT cell was treated with PBS for 3 hours, followed by the treatment of a cell culture medium (DMEM) and isotonic solution (PBS) and Cell Bio Fluid $Sync^{TM}$ for 3 hours each. Then, MTT assay and image analysis were conducted. In the clinical skin improvement test, twenty-one healthy women participated. Participants applied cosmetics containing Cell Bio Fluid $Sync^{TM}$ on their face for a week and evaluated the skin hydration, skin roughness, brightness and evenness. All measurements were conducted after they washed off their face and took a rest under the constant temperature ($22{\pm}2^{\circ}C$) and constant humidity conditions ($50{\pm}5%$) for 20 minutes. All the data were analyzed by SPSS (version 21) software program. Results showed that Cell Bio Fluid $Sync^{TM}$ improved both the cell viability and in vivo skin conditions such as skin hydration, roughness, brightness and evenness.