• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.79-89
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• 2003

The purpose of this study is to investigate appropriate environmental factors when domestic waste is decomposed as aerobic digestion. So stabilization degree was measured after the waste is mixed as certain rates and water content was controlled by 55% and 60%. Variation of VS showed food waste in reactors of number 1, 2, 3, 4 and 5 was decomposed fully except reactor of number 6. Decomposition degree of VS in reactors of number 1, 2, 3 and 4 was not different high because Vinyl and plastic inserted played role bulking agent in reactor number 1, 2, 3 and 4. In reactors, maximum temperature indicated $57{\sim}59^{\circ}C$ and temperatures in reactors 1, 2, 3 and 4 were higher and remained longer than in reactor 5 and 6 for 2~4 days. Variation of $CO_2$ was similar to that of VS. The reduction rate of water content was low because moisture generated by oxidation fever of microorganism did not evaporated well. pH was low in the beginning of the reaction however, as time passed, it increased slightly and remained regular pattern. EC and C/N showed the same pattern as pH. Settlement and weight reduction rates were similar to the factors above. Reactor 1, 2, 3, and 4 showed higher settlement and weight reduction rate than reactor 5 and 6.

• Journal of Korean Society of societal Security
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• v.4 no.2
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• pp.49-56
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• 2011

The hydroxide precipitation method is appropriate to distinguish free metal ions with complexed metal ions with amino acids. Optimum pH conditions of hydroxide precipitation were investigated using mixed amino acids which have similar composition ratio with hydrolyzed amino acids. When applied to soil samples immobilities of Hg, Cr, and Cu ion with mixed and hydrolyzed amino acids were reasonable. But those of Cd and Zn were not sufficient.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.10
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• pp.1034-1038
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• 2008

Degradative Solidification/Stabilization(DS/S) is a modification of conventional Solidification/Stabilization(S/S) that incorporates degradative processes for organic contaminant destruction with the low cost of conventional S/S. Inorganic contaminants are immobilized and chlorinated organic contaminants are destroyed by DS/S treatment. In this study, a DS/S using cement/slag/Fe(II) systems as binder was investigated to assess its effectiveness in degrading chloroform(CF) and methylene chloride(MC) contained in hazardous liquid wastes. The initial concentration of CF was 0.26 mM, 1.0 mM, 8.4 mM, 25 mM and 42 mM and Fe(II) was 200 mM. The result showed that degradation of CF in various concentration was in one kind reaction as pseudo-first-order and 95% of 0.26 mM initial concentration of CF was removed in five days. 50 mg/L of heavy metal was added in order to accelerate the rate of degradation of MC and initial concentration of MC was 3.50 mM however, degradation did not occur in system. Thus additional studies needed for degradation of MC and more studies on other reaction pathways products will help elucidate reaction mechanisms and pathways for chlorinated methanes in cement/slag/Fe(II) systems.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.4
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• pp.23-30
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• 1999

The thermal decomposition of phase stabilized ammonium nitrate(PSAN) was studied by means of thermogravimetric analysis(TGA). In this study, potassium nitrate and zinc oxide were used as the phase stabilizers in the range of contents from 0 wt.% to 8 wt.%. The kinetics and mechanism for the decomposition were evaluated using integral methods. It was found that the thermal kinetic parameters such as activation energy(I) and frequency factor(A) increase with the increase of the stabilizer contents, and the mechanism of decomposition also changes.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.1
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• pp.109-118
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• 2001

In the stage of aftercare in waste landfill management, it is very difficult to estimate the decomposition of landfill waste by excavation which damages the low permeability layer. This study developed the method to analyze the amount of landfill waste degraded bio-chemically as the types of leachate and gas, and applied the method to Nanjido landfill(NL). Application result showed that 70% of high biodegradable waste in NL was transformed to gas and leachate by 2000. Also this study suggested that the transformed portions of waste name for "Decomposition Index" at that time and the proposed method must be modified according to the biological condition of waste degradation.

• Proceedings of the Optical Society of Korea Conference
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• 1988.06a
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• pp.98-103
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• 1988

1983년 10월에 개최된 제 17차 국제도량형 총회에서 '미터는 비칭 진공속에서 299 792 458분의 1초동안 진행한 경로의 길이이다.'로 정의 됨에 따라서 미터의 현장장비인 분자의 초미세 구조 흡수선에 주파수 안정화한 레이저의 광주파수 및 진공파장이 표준선으로 추천되었다. (1) 본 연구에서는 이들 주파수 안정화 레이저 중 하나인 옥소안정화 헬륨 네온 레이저 (파장 633㎚)를 개발하고 이에 대한 연구의 결과를 기술하였다.

• Analytical Science and Technology
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• v.23 no.6
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• pp.560-565
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• 2010

Perchlorate ion ($ClO_4^-$) has been widely used as oxidizing agent in military weapon system such as rocket and missile fuel propellant. So it has been challenging to remove the pollutant of perchlorate ion. nanoscale zero valence iron (nZVI) particles are widely employing reduction catalyst for decomposition of perchlorate ion. nZVI particles has increasingly been utilized in groundwater purification and waste water treatment. But it have strong tendency of aggregation, rapid sedimentation and limited mobility. In this study, we focused on reduction of perchlorate ion using nZVI particles immobilized in alginate polymer bead for stabilization. The stabilized nZVI particles displayed much greater surface area, and much faster reaction rates of reduction of perchlorate ion. In this study, an efficient way to immobilize nZVI particles in a support material, alginate bead, was developed by using $Ca^{2+}$ as the cross-linking cations. The efficiency and reusability of the immobilized Fe-alginate beads on the reduction of perchlorate was tested at various temperature conditions.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.3
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• pp.15-21
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• 2009

In this paper, we consider the design problem of robust stabilization and robust guaranteed cost state feedback controller for discrete-time singular systems with parameter uncertainties by LMI(linear matrix inequality) approach without semi-definite condition and decomposition of system matrices. The objective of robust stabilization controller is to construct a state feedback controller such that the closed-loop system is regular, causal, and stable. In the case of robust guaranteed cost control, the optimal value of guaranteed cost and controller design method are presented on the basis of robust stabilization control technique. Finally, a numerical example is provided to show the validity of the design methods.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.3
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• pp.249-256
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• 2005

Thermal decomposition and stabilization characteristics of the solid cake after the dissolution of nitrate of the lagoon sludge was investigated. Most of the nitrates were dissolved in the water and removed to the filtrate, but small amount of nitrates, calcium carbonate and uranium were remained in the solid cake. The solid cake was thermally decomposed in the muffle furnace at $900^{\circ}C$ for 5 hours. Uranium, which is in the lagoon 1, was stabilized with $NaNO_3$ decomposition to $Na_{2}O{\cdot}2UO_3$ form. For the lagoon 2, it is confirmed that CaO, which was created by thermal decomposition of the $Ca(NO_3)_2$ and $CaCO_3$, was transferred to $Ca(OH)_2$ in the air with water. Because it is known that $Ca(OH)_2$ is stable material, further additives did not need to the stabilization of the thermal decomposition of the lagoons.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.10
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• pp.679-684
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• 2014

Many burial sites were constructed to suppress the spread of foot and mouth disease during outbreak. Defected burial sites were removed when leachate leak is presumed and carcasses were moved to the circular storage tanks. However, carcasses were not decomposed possibly due to low water content, low microbial activities, and poor mixing. In this research, storage tank containing carcasses in it was modified to bioreactor to accelerate stabilization. Liquids with nutrients were added and circulated to maintain the optimum water content while extraneous microorganisms were augmented. Settlement was used as the primary index for assessing stabilization rate, and the consolidation theory was utilized to estimate the expected final settlement. 30% of carcasses is expected to be decomposed and removed from the storage tank for five years of bioreactor operation.