• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.150-157
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• 2002

One of the latest concepts in bonding are "total etch", in which both enamel and dentin are etched with an acid to remove the smear layers, and "wet dentin" in which the dentin is not dry but left moist before application of the bonding primer Ideally the application of a bonding agent to tooth structure should be insensitive to minor contamination from oral fluids. Clinically, contaminations such as saliva, gingival fluid, blood and handpiece lubricant are often encountered by dentists during cavity preparation. The aim of this study was to evaluate the effect of contamination by hemostatic agents on shear bond strength of compomer restorations. One hundred and ten extracted human maxillary and mandibular molar teeth were collected. The teeth were removed soft tissue remnant and debris and stored in physiologic solution until they were used. Small flat area on dentin of the buccal surface were wet ground serially with 400, 800 and 1200 abrasive papers on automatic polishing machine. The teeth were randomly divided into 11 groups. Each group was conditioned as follows : Group 1: Dentin surface was not etched and not contaminated by hemostatic agents. Group 2: Dentin surface was not etched but was contaminated by Astringedent$^{\circledR}$(Ultradent product Inc., Utah, U.S.A.) Group 3: Dentin surface was not etched but was contaminated by Bosmin$^{\circledR}$(Jeil Pharm, Korea.). Group 4: Dentin surface was not etched but was contaminated by Epri-dent$^{\circledR}$(Epr Industries, NJ, U.S.A.). Group 5: Dentin surface was etched and not contaminated by hemostatic agents. Group 6: Dentin sorface was etched and contaminated by Astringedent$^{\circledR}$. Group 7 : Dentin surface was etched and contaminated by Bosmin$^{\circledR}$. Group 8: Dentin surface was etched and contaminated by Epri-dent$^{\circledR}$. Group 9: Dentin surface was contaminated by Astringedent$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. Group 10: Dentin surface was contaminated by Bosmin$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. Group 11 : Dentin surface was contaminated by Epri-dent$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. After surface conditioning, F2000$^{\circledR}$ was applicated on the conditoned dentin surface The teeth were thermocycled in distilled water at 5$^{\circ}C$ and 55$^{\circ}C$ for 1,000 cycles. The samples were placed on the binder with the bonded compomer-dentin interface parallel to the knife-edge shearing rod of the Universal Testing Machine(Zwick Z020, Zwick Co., Germany) running at a cross head speed or 1.0 mm/min. Group 2 showed significant decrease in shear bond strength compared with group 1 and group 6 showed significant decrease in shear bond strength compared with group 5. There were no significant differences in shear bond strength between group 5 and group 9, 10 and 11.

• Fashion & Textile Research Journal
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• v.22 no.4
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• pp.534-539
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• 2020

Experimental research is needed to provide information on the removal of bloodstains since washing clothes contaminated with blood is necessary for medical related fields (such as ambulance workers and doctors) as well as for women of childbearing age. This study investigated efficient washing conditions for the removal of bloodstains with a focus on washing temperature, fiber type and blood ageing time. Polyester/cotton fabric showed the highest detergency from among three fabrics that were influenced by the composition of the fiber and the structure of the yarn and fabric. When examining the effect of detergent, it was concluded that the alkalinity over pH 10 was essential to remove bloodstains and that auxiliary agents such as soil antiredeposition agents and bleach had a significant effect on the removal of bloodstains. Washing temperature showed the highest detergency at 20℃ due to the activity of the enzyme without the denaturalization of blood. Blood-ageing influenced detergency by inducing changes in the adsorption area and chemical bond. A combination of methods such as quick removal after contamination, use of alkaline detergents including soil antiredeposition agents and bleach, and low-temperature washing could help remove bloodstains.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.3928-3932
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• 2011

We synthesized peptide-resin conjugates (1 and 2) by immobilizing ${\beta}$-sheet antibacterial peptide and ${\alpha}$ helical antibacterial peptide on PEG-PS resin, respectively. Conjugate 1 showed considerable antibacterial activity in various conditions, whereas conjugate 2 did not exhibit antibacterial activity. The growths of various bacteria were inhibited by conjugate 1 even at lower concentrations than MIC. Conjugate 1 killed bacteria at MIC and had a potent synergistic effect with current antibacterial agents such as vancomycin and tetracycline, respectively. Overall results indicate that polymer surface modification using antibacterial ${\beta}$ sheet peptide is a powerful way to prevent microbial contamination on polymer surfaces.

• Clean Technology
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• v.3 no.2
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• pp.31-33
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• 1997

Nitrate contamination in surface water and ground water have increased in Korea. This trend has raised concern because nitrates caused methemoglobinemia in infants. To remove nitrates from waters, various purification processes including ion-exchange, biological denitrification, and chemical denitrification are currently in use for the treatment of water. However, little economically advantageous process exists for the industrial scale treatment of effluents highly polluted with nitrates. A new process has been developed for nitrate and other salts removal from polluted waters. Alumina cement and lime served as precipitating agents to remove nitrate with stirring at basic pH. Decreasing alumina content in alumina cement result in a increasing in nitrate removal yield. Stable removal of nitrate(1000mg/L) was readily achieved by two-stage removal process.

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.1-7
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• 2001

Ammonia is used in the manufacture of fertilizers, refrigerants, stabilizers and many household cleaning agents. These wide applications resulted in ammonia contamination in water. Ammonia can be removed from water by physical, biological, and chemical methods. Ozonation is effictive in the treatment of water with low concentration of ammonia. This study is undertaken to provide kinetic data for the ozonation of ammonia with or without hydrogen peroxide. The results were as follows; The destruction rate of ammonia increased gradually with the influent hydrogen peroxide concentration up to 0.23 mM and inhibited in the range of 0.23~11.4mM, and the maximum removal rate of ammonia achieved at 0.23mM of hydrogen peroxide, and the overall kinetics was first order. The combination effect of hydrogen and ozone to oxide ammonia in aqueous solution was better than ozone alone. The reacted ammonia was converted completely to nitrate ion.

• Journal of environmental and Sanitary engineering
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• v.17 no.2
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• pp.1-10
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• 2002

Ammonia is used in the manufacture of fertilizers, refrigerants, stabilizers and many household cleaning agents. The wide applications result in ammonia contamination in water. Ammonia can be removed from water by physical, biological, and chemical methods. Especially ozonation is effective in the treatment of water with low concentration of ammonia. Therefore, this study is undertaken to provide kinetic data for the ozonation of ammonia with bromide. The results were as follows; Ammonia oxidized by ozone with bromide catalysis. The denitrification rate of the ammonia increased proportionally to the concentration of bromide, and the overall reaction order was zero. It was also found that the effect of bromide ion concentration on the denitrification can be expressed by Monod type equation and there was no more effect above a proper bromide ion concentration. The reacted ammonia was converted completely to nitrate ion without bromide, but the denitrification of ammonia by ozone was conducted in the presence of bromide.

• Environmental Analysis Health and Toxicology
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• v.15 no.4
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• pp.115-122
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• 2000

Biocides, or non-agricultural pesticides, are a broad class of chemical. They are including biological agents used to disinfect/sanitize, pesticides for non-agricultural use, wood preservatives, antifoulants, etc. Since the early 1980s, many adverse effects of biocides to human health and ecosystem have been found in the world. Especially, antifouling biocide like TBT caused serious toxic effects on the marine organisms. Therefore, OECD began to work on biocides in mid 1996 to help Member countries co-operate in the assessment and registration of these products. EU also announced the Biocidal Products Directive (BPD, 98/8/EC) in 1998 to harmonize regulatory approaches to allow EU countries to conduct evaluations of biocides more efficiently. Korea just start to consider of biocides regulation. Some biocides products are regulated, but not all the biocides which are using in Korea. Therefore, we need to make a appropriate regulation for the all biocides categories. In addition, there are necessary to develop risk assessment tools, to survey the use pattern and amount, to research on the ecosystem contamination by the biocides .

• Journal of Environmental Health Sciences
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• v.5 no.1
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• pp.51-57
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• 1978

Antibiotics susceptibilities of Staphylococci were tested to get useful data for prevention food contamination and treatment of food poisoning. Tested were colony counts, isolation of Staphylococci, identification for the Staphylococcus aureus and resistant patterns to antimcrobial agents. The colonies and Staphylococci isolated from the atmosphere of 37 home kitchens in the morning (07:00-08:00) on Nov. 19, 1977 in Busan. The findings are as follows: 1. The average of colony counts was shown to be 9.6 ranging from 47 to 1 at mean temperature of 18$\circ$C (the highest 21$\circ$C, the lowest 15$\circ$C) 2. Out of total 37 kitchens, 18 Staphylococci were isolated from 15 kitchens with 40.5 per cent, and 4 Staphylococcus aureus were identified with 22.2 per cent from 18 Staphylococci. 3. Isolated Staphylococci were resistant to penicillin(100%), dihydrostreptomycin(93.3%), tetracycline (93.3%) and oleandomycin(66.6%), while the strains were sensitive to sulfonamide(88.6%) and colistin(83.3%). 4. Staphylococcus aureus identified were resistant to dihydrostreptomycin, penicillin and tetracycline, while the strains were sensitive to sulfonamide and colistin.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.611-612
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• 2006

In a manufacturing technique of the sintered filter, pressureless sintering method has good permeability, it is not need the binder and lubricant used on compacting process, so it has little contamination and it is easy to control the pore size and shape but the mechanical strength is low relatively and it is difficult that parts of complicate form are manufactured. In the case of manufacturing the filter by press and sintering method, in order to be satisfactory characteristic of un-pressed filter, in this study sintered metal filter fabricated by using 30-40mesh stainless steel 316L powder and additive agents. Porosity and structure of pores, permeability and mechanical strength of the sintered filter were investigated with the variation sintering conditions. Porosity was nearly constant about $60{\sim}70%$, density, permeability and mechanical strength were changed markedly with quantity of additive materials and sintering conditions.

• Korean Journal of Veterinary Service
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• v.46 no.3
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• pp.203-210
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• 2023

Breeding ducks are susceptible to fungal infections due to being bred in confined spaces for long periods. The objective of this study was to show the real state of the clinical fungal contamination of 22 duck breeding farms in Chungcheongbuk-do, South Korea. Out of the 430 carcasses obtained from the 22 duck breeding farms, 80 were diagnosed with invasive pulmonary aspergillosis (IPA). Aspergillus spp. were detected as the causative agents, including 26 cases of A. fumigatus, 35 cases of A. flavus, and 19 cases of A. terreus. The clinical lesions in the breeding ducks had circumscribed cream-and-yellow-colored plaques and/or white-to-greenish mycelium. Septate hyphae with parallel walls and dichotomous branching were observed in the histopathological lesions. AGMAg ELISA was performed to determine the overall positive rate of Aspergillus spp. in duck breeding farms. These results showed a positive rate of 58.97% for Aspergillus spp. Additionally, the positive rate increased with the age of the host.