• Animal cells and systems
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• v.6 no.3
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• pp.187-193
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• 2002

It has long been recognized that exposure to low levels of toxic chemicals could have beneficial effects, such as increased resistance to related chemicals or stimulation of growth or development. The notion of radiation hormesis, that exposure to low levels of ionizing radiation could produce beneficial effects, developed seriously in the late 1950’s, and was, to most radiation scientists, incredible. This was due in pan to the then prevailing ideas of radiobiological mechanisms, in part to the sweeping generalizations made by the leading proponents of the radiation hormesis concept, and in pan to the many failures to confirm reports of beneficial effects. More recent understanding of the mechanisms of radiation damage and repair, and discoveries of induction of gene expression by radiation and other genotoxic agents [the adaptive response] make it seem inevitable that under suitable conditions, irradiation will produce beneficial effects.

• Nuclear Engineering and Technology
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• v.35 no.5
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• pp.482-496
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• 2003

effectiveness of the PAM graphite-electrode technology for the treatment of many types of low-level radioactive waste including : combustible material, solidified resins in cement, inorganic materials, steel, glass, and solidified boric acid cement. The objectives of PAM-200 evaluation were to verify that 1) the facility meets air emission regulations, 2) the facility can be safely operated when processing hazardous and radioactive materials and 3) satisfactory final waste forms can be produced. Results, derived from KAERI's(Korea Atomic Energy Research Institute) analyses for samples of vitrified product, scrubbing solution and offgas collected during test period, show that PAM-200 can treat radioactive wastes as well as hazardous wastes with toxic constituents and radionuclides contained in the offgas exiting from the stack to the environment controlled to be far lower than the limit regulated by air conservation law and atomic law.

• Applied Biological Chemistry
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• v.27
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• pp.18-28
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• 1984

In order to improve feed values of Korean agricultural by-products, various treatments including physical, chemical, physicochemical and fermentation were suggested in th is review article. Physical treatments such as chopping, grinding and pelleting reduce partiole size of agricultural by-products, and increase passage rate from the rumen, thus may increase voluntary feed intake and weight gain. Digestibility and voluntary feed intake of straw, rice hull and sawdust, also, may be increased by chemical treatment using sodium hydroxide or ammonia. Especially, because nitrogen content of by-products increase and toxic problem is not posed by ammonia treatment, it's practical usage is recommended in Korea. Silage or fermentation treatment using principles of microbial fermentation may improve palatability of low quality by-products. As mentioned above, it is concluded that various treatments suggested are desirable and improve feed value but may raise several problems. Unfortunately, because cost for installation and products is great and processing work is complicate, farmers are not using well these processing methods until now. Therefore, in order to increase the practical usage at farm level, it is thought that many research works be achieved for efficient process which have simple operation and low installation cost.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.86-86
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• 2003

Copper has attracted much attention in the deep submicron ULSI metallization process as a replacement for aluminum due to its lower resistivity and higher electromigration resistance. Electroless copper deposition method is appealing because it yields conformal, high quality copper at relatively low cost and a low processing temperature. In this work, it was investigated that effect of the microstructure of the substrate on the electroless deposition. The mechanism of the nucleation and growth of the palladium nuclei during palladium activation was proposed. Electroless copper deposition on TiN barriers using glyoxylic acid as a reducing agent was also investigated to replace toxic formaldehyde. Furthermore, electroless copper deposition on TaN$\sub$x/ barriers was examined at various nitrogen flow rate during TaN$\sub$x/ deposition. Finally, it was investigated that the effect of plasma treatment of as-deposited TaN$\sub$x/ harriers on the electroless copper deposition.

• Toxicological Research
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• v.18 no.2
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• pp.107-116
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• 2002

Arsenic (As) is a ubiquitous element found in several forms in foods and water. Although certain foods, such as marine fish, contain substantial levels of organic arsenic forms, they are relatively low in toxicity compared to inorganic forms. in contrast, arsenic in drinking water is predominantly inorganic and highly toxic. Chronic ingestion of arsenic-contaminated drinking water is therefore the major pathway posing potential risk to human hearth. since the early 1990s in Bangladesh ozone, arsenic exposure has caused more than 7,000 deaths and uncounted thousands shout symptoms of long-term arsenic poisoning. Significant portion of world populations are exposed to low to moderate levels of arsenic of parts per billion (ppb) to hundreds of ppb. As a consequence, the World Health Organization (WHO) and U.S. environmental health agencies, such as the Environmental Protection Agency (EPA) made arsenic their highest priority. Recently, the WHO, European Union (EU), and US. EPA lowered an acceptable level of 10 ppb for arsenic in drinking water In this article, various health effects of arsenic in drinking water were reviewed and the current status for risk assessment to regulate arsenic in drinking water was discussed.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.711-714
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• 2001

A new technology to make fluoride gas such as NF$_3$contained in the exhaust gas from semiconductor manufacturing plants convert directly into a harmless substance have been established and new concept on the disposal treatment of global warming gases were presented. Experimental results verify that the chemical reactions can be take place at substantially lower temperature of 80-40$0^{\circ}C$ as compared with the combustion treatment method. Reaction product is mainly metal fluoride which is a harmless and a valuable chemical material as one of new resources. The other favorable characteristics are that the continuous treatment is possible at a low temperature under atmospheric pressure. Furthermore this process is compact, easily controllable and safely operable at low running cost. This paper concerns with a new harmless disposal treatment of toxic global warming gas.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.309-314
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• 2009

The unpredicted worldwide oil price makes the energy efficiency technology be more importance than any other period. The small cogeneration system is one of the most representative technology among the energy efficiency technologies, and the Stirling engine cogeneration system has been concerned and investigated due to the preferable characteristics - low toxic emission, low noise and vibration level, and the various form of fuel. A tiny, 1kW of electrical output, gas fueled Stirling engine cogeneration system was investigated. The electrical efficiency and thermal efficiency of the system were measured. The experiment was executed at an independent Stirling engine mode, independent secondary burner mode, and the combined mode. Part load characteristics of the Stirling engine cogeneration system were investigated also. With the efficiency characteristics, the $O_2$ and NOx emission characteristics were measured.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.243-246
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• 2002

Surfactant-enhanced electrokinetic remediation is an emerging technology that can effectively remove hydrocarbons from low-permeability soils. In this study, the electrokinetic remediation using APG(alkyl polyglucoside) was conducted for the removal of phenanthrene from kaolinite. APG, which was an environmentally compatible and non-toxic surfactant, was used at concentrations of 5, 15, and 30g/1 to enhance the solubility of phenanthrene. Also an electrolyte solution was used for considering a relation between electrical potential gradient and removal efficiency of phenanthrene. When the electrolyte solution was used, it represented low electrical potential gradient, but the removal efficiency was lower than that of no electrolyte system. Removal efficiency of phenanthrene in EK process using surfactant solution depended on concentration of surfactant. Because surfactant increased the solubility and the mobility of phenanthrene, when surfactant concentration was high, high removal efficiency was observed.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.4
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• pp.63-65
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• 2008

The increased interest in reducing the environmental effects caused by releasing organic compounds and aqueous waste has motivated the development of polymeric materials in supercritical fluids. Recently, supercritical fluids have been used in material synthesis and processing because of their special properties, such as high diffusivity, low viscosity, and low surface tension. Supercritical carbon dioxide is the most attractive because it is non-toxic, non-flammable, and has moderate critical temperature and critical pressure values. Supercritical carbon dioxide can also swell most polymers. In this study, we prepared polymer/clay nanocomposites using supercritical fluids. Cloisites 10A, 15A, 25A, and 30B used in this study are montmorillonites modified with a quaternary ammonium salt. The nanocomposites of polymer/clay were characterized by X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry.

• Journal of the Korean Ceramic Society
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• v.36 no.5
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• pp.497-503
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• 1999

Recently regenerative burner system was developed and begins to be gradually used for better energy savings. Compared to conventional burner system the regenrative one has the several merits such as higher fuel efficiency light weigh of apparatus low harmful toxic gas and homogeneous heating zone etc. The regenerative material a very important component of the new regenerative burner system should possess the properties of low specific density higher surface area and high specific heat capacity. Ceramics is the best regenerative material because of stable mechanical properties even at high temperature and better thermal properties and excellent chemical stability. In this study alumina ball alumina tube 3-D ceramic foam and hoeycomb as regenerative materials were tested and evaluated. The computer silumation was conducted and compared to the result of field test. This paper is aimed to introduce a new application of ceramics at high temperature.