• Korean Journal of Materials Research
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• v.20 no.2
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• pp.97-103
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• 2010

In this study, a new, relatively simple fabrication method for forming a mesoporous $Al(OH)_3$ film on Al substrates was demonstrated. This method, i.e., alkali surface modification, was simply comprised of dipping the substrate in a $5\times10^{-3}$ M NaOH solution at $80^{\circ}C$ for one minute and then immersing it in boiling water for 30 minutes. After alkali surface modification, a mesoporous $Al(OH)_3$ film was formed on the Al substrate, and its chemical state and crystal structure were confirmed by XPS and TEM. According to the results of the XPS analysis, the flake-like morphology after the alkali surface modification was mainly composed of $Al(OH)_3$, with a small amount of $Al_2O_3$. The mesoporous $Al(OH)_3$ layer was composed of three regions: an amorphousrich region, a region of mixed amorphous and crystal domains, and a crystalline-rich region near the $Al(OH)_3$ layer surface. It was confirmed that the stabilization process in the alkali surface modification strongly influenced the crystallization of the mesoporous $Al(OH)_3$ layer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.5
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• pp.601-604
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• 2009

This study was conducted to examine the effect of aqueous chlorine dioxide treatment as a washing method on removal of pesticide residues. Three pesticides of chlorpyrifos, diazinon, and metalaxyl, which are commonly used in vegetable crops, were treated with 10, 50, and 100 ppm of aqueous chlorine dioxide and decomposition of the pesticides was determined using gas chromatography. Three pesticides used in this study were decomposed by aqueous chlorine dioxide treatment and removal rate was proportional to treatment time as well as concentration of aqueous chlorine dioxide. In particular, 100 ppm of aqueous chlorine dioxide treatment decreased the pesticides efficiently. In addition, lettuce was treated by dipping in distilled water and 100 ppm aqueous chlorine dioxide, respectively, and was compared regarding removal efficiency of the pesticides. The results revealed that washing with 100 ppm aqueous chlorine dioxide for 10 min was the most effective for removing the pesticides. These results suggest that aqueous chlorine dioxide can be used as a washing method of fresh produce to remove the residual of pesticides.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.6
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• pp.803-811
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• 2012

Oriental Medicine always attach great importance to the damp diseases. Dampness is related with many organs and many clinical diseases. The cause and the location of the damp disease, nature of the symptoms, combination with other pathogenic factors are very diverse. This article analyzed the concept, cause of disease, pathogenesis, characteristic of symptoms, treatment method and prescriptions of Epidemic Warm Diseases of dampness syndrome and cases of dampness-heat diseases based on the theories of Epidemic Warm Diseases and found that theories of Epidemic Warm Diseases have very wide area of application. Dampness is classified into cold-dampness and dampness-heat by combination of heat or cold. The dampness syndrome is related with organs such as lung, spleen, kidney, triple energizers and bladder, and affects liver and heart. The basic treatment methods are dispelling dampness turbidity and diffusing qi movement. The detail treatment methods are spreading lung qi with lightness and resolving dampness and excreting turbidity in upper energizer, opening and dipping down with pungent-bitter and diffusing qi movement and strengthening the spleen and stomach in the middle energizer, draining dampness with bland in the lower energizer. Warming Yang is the main method of treatment for cold-dampness and clearing heat is for dampness-heat with the assistant methods such as resolving dampness and promoting the flow of qi. 5. Acute fever, virus diseases, epidemic diseases among modern diseases are much related with the dampness-heat syndrome.

• Analytical Science and Technology
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• v.6 no.5
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• pp.521-530
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• 1993

According to the Montreal Protocol, CFC 113, one of the ozone-depleting substances, will be prohibited to use as a cleaning solvent essentially in the electronic industry. Therefore, the development of the alternative cleaning solvents to CFC 113 is being accelerated. A number of the alternative cleaning solvents are avialable on the market. The alternatives of Axarel 32(DuPont), Cleanthru 750H(KAO Chemical), and EC-Ultra(Petroferm) are chosen for the comparison of cleaning performance with CFC 113. The test methods for measuring the cleaning performance were composed of the measurement of the physical properties, the experiments on the material compatibility with cleaning solvents, the measurement of the evaporation rate, and finally the experiments of the removal efficiency. Normally the basic physical properties of the alternatives had higher boiling points, viscosity and surface tension, which were quite different to those of CFC 113. In terms of solubility of rosin-based flux, the solubilities of abietic acid (nonpolar organic) were similar, but those of the activator (polar organic) in the alternatives were better than CFC 113. The evaporation of the alternatives was very slow, compared to CFC 113, which had much lower boiling point. All the cleaning solvents showed the good material compatibility with FR4 and Cu-coated PCB. The better removal efficiencies of abietic acid were obtained when using the ultrasonic mechanical energy over the dipping method. The experiments also indicated the very slow-eavaporating solvent was not desirable with the dipping cleaning method, and the differences in the removal efficiency of the alternatives with the ultrasonic cleaning method were negligible. Among the alternatives, the overall cleaning performances were obsorved as almost similar. Before selecting the ultimate cleaning solvent, the application of cleaning machine, environmental issues, and economics are simultaneously considered with the cleaning performance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.104-115
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• 1992

The rice culture techniques included 'Jodosukyungbeob'(旱稻水耕法 : culture techniques of early-ripening paddy rice), 'Mandosukyungbeob' (晩稻水耕法) : culture techniques of late-Ripening paddy rice 'Handobeob'(旱稻＆lt;山稻＆gt;法 : culture techniques of upland rice), 'Myojongbeob'(苗種法 : culture techniques of paddy rice by transplanting), 'Kunangbeob'(乾秧法 : culture techniques of rice by transplanting which rears seeding in dry paddy) and 'Sudogunpanongbeob'(水稻乾播農法 : culture techniques of paddy rice seeding in dry field). Especially, 'Kunangbeob' and 'Sudogunpanongbeob' were originally developed in Korea as seen in 1600s(Kyoungje : 經濟) and early 1800s (Yoji : 要旨). In 'Jodosukyungbeob' it took 9 days for seed dipping, water-sprouting and prevent damage by birds, each for 3 days in China, but in Korea seed dipping in water took 3 days and the rest of the procedures were flexibly established. In matured soils, practices were fall plowing right after harvest, recognition of effective tillering and additional fertilization use of human manure, and stimulation of sprouting by lime application. The unique culture techniques adequate for Korean situations were practiced, which included weed control after draining accurately for 3 to 4 times, draining at mid season for improving wind and drought tolerance, rice harvesting at appropriate time for preventing grain shattering, and seeding in rows. 'Mandosukyungbeob' was improved techniques contrast to those of China, and the major contents were selection of proper varieties, good stand establishment by seeding high rates, induction of vigorous tillers, and adoption of 'Jokjongbeob'(足種法 : seeding method by foot). Also, one of the most prominent rice cultures by our ancestors was 'Kunpanongbeob' that was systemized form habitual practice of Pyongan Province. The unique technique actualized was 'Hando [旱稻(山稻)]' culture technique which was the combinations of 'Jokjongbeob', root stimulation method, and disaster-tolerant mixture cropping with adoptation of variety theory, although it was originated from China. The transplanting techniques has come before 'Jikseol'($\ulcorner$直說$\lrcorner$) and its merits were sufficiently realized. However, this method was basically prohibited from the early Chosun dynasty because extremely bad harvest was expected under drought conditions and insufficient conditions of water storage. But, it was permitted in the areas that contained water all the times and in case of large-scale farming especially. Most of rice culture was transplanted in the end of the Chosun dynasty because transplanting was continuously spreaded in the three southern provinces of Korea. Under these circumstances, transplanting technique was improved from the early to the end of the Chosun dynasty by weed control, fertilizing, water management, and quadratic transplanting. Based on these techniques, agricultural productivity was improved 5 times by that time. 'Kunpanongbeob' was created and developed properly for Korean conditions that is dry in early season and flooding in late season. This was successively developed and established into transplanting technique of nursery seedling.

• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.52-57
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• 2010

Although chemical sedimentation and ion exchange are usually applied to the treatment of heavy metal ions and radioactive cations, they have some serious disadvantages like a great consumption of chemicals, the disposal of valuable metals, and the secondary pollution of soil by the solid-waste. The advanced countries recently have studied the electrochemical ion exchange, combined electrochemical reduction and ion exchange, for the development of the alternative technique. This study has been performed to investigate the optimum condition for the preparation of the nickel hexacyanoferrate (NiHCNFe) which is an electrochemical ion exchanger. NiHCNFe film was deposited on the surface of nickel plate by chemical method or electrochemical method. The morphology and composition of NiHCNFe were observed by SEM and EDS, respectively. The peak current density of NiHCNFe was measured from the cyclic voltammograms of the continuous oxidation-reduction reaction in a parallel plane ion exchange electrode reactor. It was found that the chemical preparation method was better than the electrochemical method. The concentrated NiHCNFe was apparently deposited on nickel plate when dipping in the preparing solution for 118 h, especially. It also had a best durable performance as an ion exchange electrode.

• Research in Plant Disease
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• v.23 no.4
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• pp.334-347
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• 2017

Bacterial wilt caused by Ralstonia solanacearum is an important disease in cultivation of chili pepper, causing plant death and significant yield losses. Cultivation of disease-resistant varieties is the most suitable measure to control bacterial wilt of chili pepper. To establish an efficient screening method for resistant chili pepper to R. solanacearum, six resistant or susceptible cultivars to the R. solanacearum were selected and the development of bacterial wilt on the cultivars according to several conditions was investigated. Drenching bacterial suspension into the cut roots using a scalpel was more simple and effective to distinguish resistant and susceptible cultivars than inoculation methods of root-dipping or soil-drenching without wounding. A resistant pepper, 'MC4' to R. solanacearum showed high resistance under the developed conditions which were 21- to 28-day-old pepper inoculated with $1{\times}10^8cfu/ml$ of bacterial suspension. On the other hands, the susceptible cultivars represented high disease severity under the conditions. These results indicated that we developed an efficient method to evaluate resistance of chili pepper cultivars against bacterial wilt. In addition, we successfully evaluated resistance degree of 140 commercial chili pepper cultivars to R. solanacearum using the developed method.

• Polymer(Korea)
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• v.29 no.3
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• pp.282-287
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• 2005

A novel ice particle leaching method for fabrication of porous and biodegradable PLGA scaffold has been proposed for the application to tissue engineering. After uniform mixing of poly(L-lactide-co-glycolide) (PLGA) and bovine serum albumin-fluorescein isothiocyanate (FITC-BSA), the FITC-BSA loaded scaffold was fabricated by adding various ratio of ice particle. The release profiles of FITC-BSA were examined using pH 7.4 PBS for 28 days at $37^{circ}$. The release amount was determined by fluorescence intensity by using the fluorescence spectrophotometer and the morphological change of the scaffolds was observed by scanning electron microscope. The release initial burst of BSA containing scaffolds was lower than that of simple dipping scaffolds resulting in constant release aspect. Although the BSA concentration increased. the initial burst was not increased. As a result of this study, it can be suggested that ice particle leaching method for the tissue engineered scaffold miff be very useful and it is possible to impregnate with water soluble factors like cytokine. We suggest that ice particle leaching method may be useful to tissue engineered organ regeneration.

• Geophysics and Geophysical Exploration
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• v.16 no.1
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• pp.6-17
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• 2013

Multicomponent seismic data including both P- and PS-waves have advantages in discriminating the type of pore fluid, characterizing the lithologic attributes and producing the high resolution image. However, multicomponent seismic data recorded at the vertical and horizontal component receivers contain both P- and PS-waves which have different features, simultaneously. Therefore, the wavefield separation of P- and PS-waves as a preprocessing is inevitable in order to use the multicomponent seismic data successfully. In this study, we analyzed the previous study of the wavefield separation method suggested by Jeong and Byun in 2011, where the approximated reflection angle calculated only from one refernce depth is used in rotation transform, and showed its limitation for seismic data containing various reflected events from the multi-layered structure. In order to overcome its limitation, we suggested a new effective wavefield separation method of P- and PS-waves. In new method, we calculate the reflection angles with various reference depths and apply rotation transforms to the data with those reflection angles. Then we stack all results to obtain the final separated data. To verify our new method, we applied it to the synthetic data sets from a multi-layered model, a fault model, and the Marmousi-2 model. The results showed that the proposed method separated successfully P- and PS-reflection events from the multicomponent data from mild dipping layered model as long as the dip is not too steep.

• The Journal of Engineering Geology
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• v.24 no.1
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• pp.39-52
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• 2014

Limestone caves that consist of main passages and branches are formed by a variety of processes, and have the characteristic of developing with a preferred orientation controlled by discontinuities such as bedding, joints, and faults around the cave. However, it is difficult to analyze a representative orientation from various orientations. To interpret the overall development orientation of limestone caves, this study proposes new development orientation analysis methods, termed the Average Span Ratio Method (ASRM) and the Individual Development Ratio Method (IDRM), using the weighting of persistence. Nine limestone caves in Korea were randomly selected for testing the new methods. The methods show a stronger development orientation for limestone caves than that obtained by traditional methods, which consider only the distribution of development orientations. Based on an analysis of the relationship between the average span and the dip angle of bedding, it is confirmed that shallowly dipping bedding is a major contributor to the expansion of span in limestone caves. In addition, using scan-line survey data acquired in the field, we perform an RMR analysis of stability of the ground around limestone caves.