• Journal of Environmental Health Sciences
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• v.34 no.4
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• pp.316-326
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• 2008

The Earth's temperature has risen $0.76^{\circ}C$ (degree) during last 100 years which Implies a sudden rise, compare with the 4oC (degrees) rise through out the past 20,000 years. If the volume of GHG (Greenhouse Gas) emission continues at the current level, the average temperature of the Earth will rise by $1^{\circ}C$ (degree) by 2030 with the further implication that the temperature of Earth will rise by $2{\sim}5^{\circ}C$ (degrees) every 100 years. Therefore, as we are aware that the temperature of the glacial epoch was $8{\sim}9^{\circ}C$ (degrees) lower than the present time, we can easily predict that the above temperature rises can be potentially disastrous for human life. Every country in the world recognizes theseriousness of the current climate change and adopted a convention on climate change in June 1992 in Rio. The COP1 was held in March 1995 in Berlin and the COP3 in Dec. 1997 in Kyotowhere the target (2008-2012) was determined and the advanced nations' reduction target (5.2%, average)was also agreed at this conference. Korea participated in the GHG reduction plan which required the world's nations to ratify the Kyoto Protocol. Ratification of the Kyotoprotocol and the followup requirement to introduce an international emissions trading scheme will require severe reductions in GHGs and considerable economic consequences. USA are still refusing to fully ratify the treaty as the emission reductions could severely damage the economies of these countries. In order to estimate the exact $CO_2$ emission, this study statistically analyzed $CO_2$ emission of each country based on the following variables : level of economic power and scientific development, the industrial system, productivity and energy efficiency.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.379-384
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• 2006

Since the monolithic ceramic substrate was introduced for automotive catalytic converters, the durability of the substrate has been a continuing requirement to reduce the emission gas of vehicle. The substrate can occupy a volume as small as 82 $cm^3$ and as large as 8200 $cm^3$ to provide the required substrate for catalytic activity. The long-term durability varies with the size of the substrate from manufacture's point of view. Therefore This study presents that the response surface model using central composite design can explain size effect on the modulus of rupture in a cordierite ceramic monolithic substrate.

• Analytical Science and Technology
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• v.16 no.3
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• pp.240-248
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• 2003

Sulfur compounds which are well-known odor-active compounds in industrial area have very low detection threshold values. Trace amounts of volatile sulfur compounds in enviroment air around several odor sources were concentrated in liquid argon bath and determined by gas chromatograph with flame photometric detector (FPD) which exhibits very good selectivity and sensitivity. 25% ${\beta}$,${\beta}$-Oxydipropionitrile on 60/80 Chromosorb W was used as adsorbent for the preconcentration of sulfur compounds in air sample and also as packing material for a packed glass column. Concentration volume of air sample was different from place to place in the range of 0.1~3.0L. Atmospheric concentrations of sulfur compounds in air of residential districts and boundaries of business establishments, and also those in the exhausted gases of emission points such as a sewage disposal plant in industrial area were measured.

• Resources Recycling
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• v.5 no.3
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• pp.24-30
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• 1996

The computcr s~mulatiun model in vanaus s~nelllng process for melling waste cashhg sand was developed by using energy and malcrial balance concept. This modcl can prcdict the coal, flux and oxygen conaumptron and thc volume and temperature of off-gas The ~niljor critical varlablcs for smclting process can be crplained by using the analysis of energy and malc~ialb alance. Thc Innst lmportarlt variables lor smelting process were h i ~ hpo st-combust~anr atla, high heat transfer crficiency and refractory pratcclion lechnalogy. For saving encrg), in this smelting proccss, selection of caw marerials i.e coal, flus was important, cspacially ubi~go f low volatile coal was prufitahle.

• Resources Recycling
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• v.4 no.4
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• pp.37-58
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• 1995

Whole tues were put uto cement kiln inlet where the tempmalures or gas and cemcnt-raw-materials were 1050 and 800- 850.C. respcclrvely. Tl~ck iln consisls of \ulcorner-stage suspension preheatel- and air quenching coolers The amount of wusle tlrcs added in lhc normal encrgy in lhc ce~ncnlk iln was 3, 5, 7% by volume Welght and steel contents of tiles. ulti~~iaalcn d elemental analysis, ash contents. ash hsion temperature. etc, wete detcnutned to inveshgate thc prnpcrlics a1 tires and ilreir ashes. Flucluat~ons of cement kiln placess, cement quality and an pollulton were invesligalerl during lhc burning tins. When the Ieeding ralio ol wasle lires to normal cncrgy was 50'0, there was nn wlde d~ffereilces m the cemmt quctlity and air pollutcon between operation with tiles and withoul tires. Tl~ch cal iccovcry was uhout 50% w~th5 % add~tionI n the nonndl energy. There was a little lxt fluctuation of cement quultty ncld an pollution at olher feeding ralios.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.2
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• pp.143-150
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• 2010

Vitrification technology has been gradually recognized as one of effective solidification methods for concentrated boric acid wastes generated in PWR. Vitrification for low- and intermediate-level radioactive wastes has a large volume reduction and good durability for the final products. A feasibility study for the vitrification of concentrated boric acid wastes has been performed with developing the pre-treatment methods of powdered wastes, glass compositions using glass formulation and demonstration test. The pre-treatment method is pelletizing the powder type for stable feeding within cold crucible melter. The glass compositions should be developed considering molten glass are related with wastes reduction. High contents of sodium and boron within borate wastes give influence to waste loading. A variety of factors obtained from the demonstration test are reviewed, which is wastes feeding rate, off-gas characteristics on stack and glass characteristics of final products such as durability for implementing the wastes disposal requirement. The aim of this paper is to present the feasibility of vitrification and review the solidification method for concentrated boric acid wastes and obtain the physicochemical characteristics of solidified glass.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.2610-2616
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• 2014

An ejector is a kind of pump which is using pressure energy of high pressure fluid. This study aims to investigate performance influencing according to change the ejector mixing section shape using CFD simulation by Finite Volume Method. Optimum conditions were suggested 3 kind of variable such as nozzle diameter, nozzle length, distance from nozzle tip to the diffuser inlet. The results, It was confirmed that the diameter of the nozzle was the greatest effect in performance of the ejector. The diameter of the nozzle get smaller, mixing ratio was increased. On the other hand, nozzle length, distance from nozzle tip to the diffuser inlet had little effect on performance. It was proposed specific Mixing section, Nozzel diameter 23.8mm using the Artificial Neural Network.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.396-400
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• 1989

The oxygen index test was carried out to obtain the relative flammability of wood-based materials (plywood, MDF, particleboard) and their oxygen indices. The oxygen index is the minimum concentration of oxygen, expressed as volume percent, in a mixture of oxygen and nitrogen that will just support flaming combustion of a material under the specified laboratory conditions. In this study the oxygen indices were calculated by using the Dixon and Massey's Up and Down method("N" Large method). The obtained results were as follows : 1. The oxygen indices calculated with Up and Down method were 27.9% for plywood, 26.9% for MDF, and 26.2% for particleboard, indicative of plywood being more difficult to burn than MDF and particleboard Lender the same surrounding conditions. 2. The oxygen indices were not affected by the total gas flow rate.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.12-18
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• 2014

A study of gas generator Fuel-Rich propellant for air-breathing propulsion system was performed in this paper. General solid propellant comprises a mean of 60% or more oxidizing agents. but, to develop the fuel-rich solid propellant increased the content of the metal fuel and reduced the content of the oxidizing agents by approximately 30%. Very high amount of heat per volume of fuel into the metal having the Boron was used. Amorphous Boron Powder was applied to propellant as beads type and it allowed to design more amount of metal fuel in the fuel-rich propellant. And the Combustion characteristics and properties of fuel-rich solid propellant according to the Boron-bead sizes were confirmed.

• Computers and Concrete
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• v.21 no.6
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• pp.717-726
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• 2018

Concrete pipelines are the most efficient and safe means for gas and oil transportation over a long distance. The use of nano materials and nono-engineering can be considered for enhancing concrete pipelines properties. the tests show that $SiO_2$ nanoparticles can improve the mechanical behavior of concrete. Moreover, severe hazard for pipelines is seismic ground motion. Over the years, scientists have attempted to understand pipe behavior against earthquake most frequently via numerical modeling and simulation. Therefore, in this paper, the dynamic response of underwater nanocomposite submerged pipeline conveying fluid is studied. The structure is subjected to the dynamic loads caused by earthquake and the governing equations of the system are derived using mathematical model via Classic shell theory and Hamilton's principle. Navier-Stokes equation is employed to calculate the force due to the fluid in the pipe. As well, the effect of external fluid is modeled with an external force. Mori-Tanaka approach is used to estimate the equivalent material properties of the nanocomposite. 1978 Tabas earthquake in Iran is considered for modelling seismic load. The dynamic displacement of the structure is extracted using differential quadrature method (DQM) and Newmark method. The effects of different parameters such as $SiO_2$ nanoparticles volume percent, boundary conditions, thickness to radius ratios, length to radius ratios, internal and external fluid pressure and earthquake intensity are discussed on the seismic response of the structure. From results obtained in this paper, it can be found that the dynamic response of the pipe is increased in the presence of internal and external fluid. Furthermore, the use of $SiO_2$ nanoparticles in concrete pipeline reduces the displacement of the structure during an earthquake.