• Research in Plant Disease
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• v.21 no.3
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• pp.193-200
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• 2015

Gray mold caused by Botrytis cinerea is one of the most important postharvest fungal pathogens of cut flowers. Here, gamma irradiation, an alternative for phytosanitary purposes, and sodium dichloroisocyanurate (NaDCC) were used to control B. cinerea in a cut chrysanthemum (Chrysanthemum morifolium Ramat.) cultivar, 'Baekma', one of the cultivars susceptible to B. cinerea. Spore germination and mycelium growth of B. cinerea were inhibited by gamma irradiation in an inversely dose-dependent manner. A dose of 4 kGy completely inhibited the mycelium growth of B. cinerea. A significant change in flower quality (physical properties) on chrysanthemum was shown from gamma irradiation at over 0.2 kGy (p<0.05). Therefore, in this study, the integration of gamma ray (below 0.2 kGy) and NaDCC, an eco-friendly form of chlorine, was investigated to control the disease with low dose of gamma irradiation dose. Interestingly, the gamma irradiated flowers showed more disease severity than the non-irradiated flowers. The combined treatment of gamma irradiation and NaDCC does not affect the severity of the fungal disease, whereas only 70 ppm of NaDCC treatment showed a significantly reduced severity. These results suggest that only chlorination treatment can be applied to control B. cinerea in cut chrysanthemum flowers.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.6
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• pp.37-42
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• 2004

It is necessary for what just keep a living body balance be devoted to it being varied with acidity serious trouble, and constitution of a study person about the density (ph) change that an alkaline ion necessary for a living body is numerical to supply a human body with number alkali by PWM voltage control. Works in the water which included the calcium (Ca), kalium (K), magnesium (Mg), natrium (Na) back who is helpful for a human body, and there is Alkaline. It is done this alkaline electrolysis to ask in order to create a number, and minerals are gathered through isolated layer (isolated special layer) to a - electrode direction, and is created. of course, prominent derelicts gather, and the acidity capital is happened, and -ion of a chlorine (Cl), phosphorus(P), sulfur (S) back is usable unfavorably in water of different use to a + electrode direction. Microprocessor was used with a - pole and a + pole with a PWM(pulse width modulation) voltage in this electrolysis process, and four kinds of PWM voltages were implemented, and a voltage every ph density change tried to be considered. It is expected by getting exactly if number alkaline ion of ph density value necessary is done with setting value if PWM control is used thus.

• Corrosion Science and Technology
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• v.7 no.2
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• pp.99-111
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• 2008

Copper was exposed unsheltered and sheltered in four humid tropical sites, representing urban, urban-industrial, urban-marine and rural environments. The corrosion rates and the sequence of corrosion product formation are presented and discussed in relation with climatic and atmospheric pollution parameters. Chemical compositions of corrosion products were found to depend on environments and duration of exposure. In all environments, cuprite was the predominating corrosion product that formed first and continuously increased during the exposure. Among the sulphur-containing corrosion products, posnjakite and brochantite were more frequently found and the first formed earlier. Nantokite was the most common chlorine-containing products for most cases, except the high-chloride environment, where atacamite was detected instead. The corrosion rate of copper was well indicated by the colour of patina. The red-purple colour corresponded to the high corrosion rate and the greenish grey colour corresponded to the low corrosion rate. Corrosion rate of sheltered copper in urban-marine environment increased with the exposure time.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.651-658
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• 2008

Estuary barrier is a hydraulic structure constructed to supply safely water as protecting chlorine penetration of sea water. However, the barrier brings about a problem which decreases original functions of estuary because hydraulic ecology was disrupted as obstructing natural water exchange between fresh water and sea water. It is important to supply Enough fresh water in the estuary ecosystem. But it is possible to reduce the problems brought from barrier throughout efficient water gate operation of estuary barrier. It was shown in this study that the environmental effect of estuary in Nakdong river was investigated according to the control of water level. Also, the basic information about the effective water gate operation was provided. The analysis results showed that the release rate of estuary was increased about 20% as changing the operational water levels. This helps supplying fresh water durably to the mixing zone. Also, CE-QUAL-W2 model was utilized to assess water quality. The values of BOD and COD were not changed in estuary area. From the result, it was analyzed the effect of water quality according to the water gate operation was not indicated.

• The Journal of Korean Academy of Prosthodontics
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• v.27 no.2
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• pp.249-259
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• 1989

Dental impression materials often become contaminated with patients' saliva and blood which creates the potential for cross-infection. It was the purpose of this study to investigate the effects of disinfection of three different rubber impression materials with four different disinfecting solutions. Polysulfide, vinyl polysiloxane and polyether impression materials were mixed according to the manufacturer's directions and samples were formed on a stainless steel model. On removal from the standard model, impressions were immersed in a disinfectant (acid-potentiated glutaraldehyde, phenollic compound, chlorine compound, iodophor) at room tempera tures for ten minutes. After disinfection, the distance between reference points(linear dimension) was measured using the non-contact automatic cordinate measuring projector(MZ-1, Nikon). Through statistical analyses on the data from this study,. the following conclusions were obtained. 1. Polysulfide, vinyl polysiloxane impressions were disinfected without dimensional change.(p>0.05) 2. Polyether impressions which were immersed in acid-potentiated glutaraldehyde were statistically different from control group.(p<0.05) But the amount of shrinkage(0.04%) would not be clinically significant. 3. By immersion of polysulfide, vinyl polysiloxane, polyether impressions in Banicide, Biocide, Multicide plus, sodium hypochlorite for ten minutes, clinically accurate impressions were obtained without dimensional change.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.497-500
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• 2001

Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e.g. As, Cl). The charge transport properties of amorphous Selenium is decided on hole which is induced from metal to selenium in metal-selenium junction and which is transferred in a-Se bulk. This phenomenon is resulted of changing electric field owing to increasing of space charge by deep trap of a-Se bulk. In this paper, We dopped the chlorine to compensate deep hole trap and deposited blocking layer using dielectric material to prevent from increasing space charge for injection charge between metal electrode and a-Se layer. We compared space charge and the decreasing of trap density through measuring dark and photo current. 缀Ѐ㘰〻ሀ䝥湥牡氠瑥捨湯汯杹

• Analytical Science and Technology
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• v.15 no.3
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• pp.221-228
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• 2002

AMX is one of extremely high mutagenic compound produced from the reaction of the chlorine and the organic compound during the disinfection of tap water. In this paper, the chemical derivatization of MX with 2% sulfuric acid-methanol, iso-propanol, sec-butanol and n-butanol derivatives for the GC/MS analysis were tested or compared. Limit of detection for the EI and NCI mode were 25 pg and 1.25 pg, respectively. The good linear calibration curve was obtained the range of 25~2500 pg by EI and NCI

• Corrosion Science and Technology
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• v.7 no.1
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• pp.27-34
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• 2008

In industrial and fluid handling systems, frequently the protective film forming materials suffer from severe corrosion due to microbial effects. As an example, various micro-organisms, including bacteria, exist in seawater normally fed to power and desalination plants. Unless seawater intakes are properly disinfected to control these microbial organisms, biological fouling and microbial induced corrosion (MIC) will be developed. This problem could destroy metallic alloys used for plant construction. Seawater intakes of cogeneration plants are usually disinfected by chlorine gas or sodium hypochlorite solution. The dose of disinfectant is designed according to the level of contamination of the open seawater in the vicinity of the plant intake. Higher temperature levels, lower pH, reduced flow velocity and oxidation potential play an important role in the enhancement of microbial induced corrosion and bio-fouling. This paper describes, in brief, the different types of bacteria, mechanisms of microbiological induced corrosion, susceptibility of different metal alloys to MIC and possible solutions for mitigating this problem in industry. A case study is presented for the power plant steam condenser at Al-Taweelah B-station in Abu Dhabi. The study demonstrates resistance of Titanium tubes to MIC.

• Journal of the Korean Society of Safety
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• v.8 no.4
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• pp.175-182
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• 1993

Volatilization of toxic heavy metals, especially, metal chlorides at elevated temperatures in oxidation conditions was observed using a thermogravimetric furnace since such metal chlorides used to be a cause for the disease of industrial workers by their toxicity and high volatile extent. Most of tested metal chloride compounds were evaporated or decomposed into gas phase at elevated temperatures ranged from 200~90$0^{\circ}C$, while CrCl$_3$ and NiC1$_2$became stable with converting into oxide forms. A kinetic model for evaporation/condensation could predict maximum evaporation flux and the calculated values were compared with real evaporation flux. The ratio of two fluxes could be explained as the fraction of impinging gas molecules to the condensing surface( $\alpha$ ) and obtained in the range of 10$^{-3}$ ~10$^{-9}$ for the experimented toxic heavy metal chlorides. This ratio might be used to define the volatile extent or toxicity of such toxic metal compounds. The schemes to avoid volatilization of toxic heavy metals Into the atmosphere were suggested as follows ; 1 ) controlling the compositions of metals and Chlorine produced substances( such as PVC ) in the treated materials using a reverse estimation from regulatory limit and characteristics of a processing facility, 2) Installation of wet type devices such as a scrubber for condensing the metal compounds.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.5
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• pp.460-466
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• 2001

The oxidizing power of ozone is the greatest of all commercially available oxidizers and thus ozone is taking the place of chlorine for water treatment. For energy-effective treatment of water, ozone should be generated in high concentration. A silent glow discharge ozonizer is high effective in industrial aspect and thus is the most widely used. We found that the key parameters associated with the ozone generation rate are the driving voltage of the discharger, the discharge rate and the temperature of the ozone generation tube. For an easy control of these parameters, we build a monitoring system with graphical user interface. This system is based on Windows-98 PC, programmed with C++ and LabView.