• Journal of the Korean Society of Industry Convergence
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• v.20 no.1
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• pp.56-66
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• 2017

In this experimental study, it is designed and used the test engine bed which is installed with the exhaust gas recirculation, and in addition to equipped using by oxygen adder. It has been tested and analyzed the combustion and emission characteristics, cycle variability and engine performance by controlling the oxygen volume fraction, EGR rate, engine speed and equivalence ratio.

• Advances in concrete construction
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• v.6 no.6
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• pp.585-610
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• 2018

In this study, vibration analysis of a concrete foundation-reinforced by $SiO_2$ nanoparticles resting on soil bed is investigated. The soil medium is simulated with spring constants. Furthermore, the Mori-Tanaka low is used for obtaining the material properties of nano-composite structure and considering agglomeration effects. Using third order shear deformation theory or Reddy theory, the total potential energy of system is calculated and by means of the Hamilton's principle, the coupled motion equations are obtained. Also, based an analytical method, the frequency of system is calculated. The effects of volume percent and agglomeration of $SiO_2$ nanoparticles, soil medium and geometrical parameters of structure are shown on the frequency of system. Results show that with increasing the volume percent of $SiO_2$ nanoparticles, the frequency of structure is increased.

• Structural Engineering and Mechanics
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• v.69 no.5
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• pp.547-555
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• 2019

In this study, vibration analysis of a concrete foundation-reinforced by $SiO_2$ nanoparticles resting on soil bed is investigated. The soil medium is simulated with spring constants. Furthermore, the Mori-Tanaka low is used for obtaining the material properties of nano-composite structure and considering agglomeration effects. Using third order shear deformation theory or Reddy theory, the total potential energy of system is calculated and by means of the Hamilton's principle, the coupled motion equations are obtained. Also, based an analytical method, the frequency of system is calculated. The effects of volume percent and agglomeration of $SiO_2$ nanoparticles, soil medium and geometrical parameters of structure are shown on the frequency of system. Results show that with increasing the volume percent of $SiO_2$ nanoparticles, the frequency of structure is increased.

• Journal of Environmental Health Sciences
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• v.29 no.1
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• pp.34-42
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• 2003

The objective of this study is to investigate the waste recycling possibility, practicability, economic efficiency and acid gas sorbent use of the hard-shelled mussel. This study is to investigate the hydration/calcination reaction and fixed bed reactor. The physical-chemical characteristics of the hard-shelled mussel were analyzed by ICP SEM-EDX, BET and pore volume. Thus, the results could be summarized as follows; Hard-shelled mussel can be used as iron-manufacture and chemical sorbents considering more than 53.7% of the mussel is lime content. The SO$_2$removal efficiency of the hard-shelled mussel after calcined hydration increased thirty times as a result of the higher pore size, specific surface area and pore volume. Also, the CaO content, pore volume, pore size distribution and specific surface area greatly influenced the SO$_2$ and NOx removal reactivity. The optimum particle diameter average of hard-shelled mussel was $\pm$100 mesh, which was applied to the sorbent on the medium/small scale waste incinerator and flue gas desulfurization processes.

• Clean Technology
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• v.10 no.1
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• pp.1-7
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• 2004

In this study, the performance of Aluminium foil etching waste(PWF100) as a cohesive agent was estimated and the methods to commercialize it were investigated through comparison of physical properties between Aluminium foil etching waste(PWF100) and commercial cohesive agent(PAC17). The height of sediment bed was measured according ot the change of the concentration of BKN-100, BKR-110, and BKR-120 prepared by using PWF100. When the concentrations of BKN-100, BKR-110, and BKR-120 were increased, the heights of sediment bed were constant after decreased. Also, the density of sediment bed was investigated according to the change of the concentration of BKN-100. When the concentrations of BKN-100 were increased, the densities of sediment bed were decreased. In addition, based on the concentration of BKN-100, BKR-110, and BKR-120, the sediment rate was experimented. When the concentrations of BKN-100, BKR-110, and BKR-120 were increased, sediment rates were rapid and then slow. Moreover, the volumes of sediment bed were measured according to the change of the concentration of BKN-100. According to increasing the concentrations of BKN-100, the required time for getting to the minimum volume of sedment bed were reduced and then increased. Lastly, the required time for sedimentation based on the concentration of BKN-100, BKR-110, and BKR-120 was investigated. When the concentrations of BKN-100, BKR-110, and BKR-120 were increased, the required times for sedimentation were increased after decreased. From these results, it can be concluded that the PWF100 acts as a cohesive agent.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1747-1756
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• 2000

Crab shell particles (Protunus trituberculatus) and activated carbon (Norit 0.8 SUPRA) were used as packing material in a fixed-bed column. When 1 g crab shell was added in the column packed with 10 g activated carbon. breakthrough to influent 10 mg Pb/L occurred at 1520 bed volumes. as compared to 380 bed volumes for 10 g activated carbon only. Addition of crab shell particles into activated carbon column resulted in increased uptake of lead. The dramatic improvement might be attributed to an increase in $co_3{^{2-}}$ and $OH^-$ available for the binding of lead. From the result of analyses, the major mechanism of lead removal was based on dissolution of $CaCO_3$ in the crab shell followed by precipitation of $Pb_3(CO_3)_2(OH)_{2(s)}$ on the surface of activated carbon. The lead uptake increased two fold as the influent lead concentration was increased from 10 to 50 mg/L. However, it decreased by 40% as the influent pH was lowered from 5.0 to 3.0.

• Journal of Korea Water Resources Association
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• v.51 no.8
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• pp.655-664
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• 2018

The riverbed material survey is to investigate the particle size distribution, specific gravity, porosity, etc. as basic data necessary for river channel plan such as calculation of sediment transport and change of river bed. In principle, the survey spots are 1 km interval in the longitudinal direction of the river and 3 points or more in the 1 cross section. Therefore, depending on longitudinal length of the river to be investigated, the number of surveyed sites is very large, and the time and cost for the investigation are correspondingly required. This study is to compare the particle size analysis method with the volumetric method and the image analysis method in work efficiency and cost and to examine the applicability of the image analysis method. It was confirmed that the diameter of the equivalent circle converted by the image analysis method can be applied to the analysis of bed material particle size. In the gravel stream with a particle size of less than 10 cm and a large shape factor, the analytical result of the bed material by the image analysis method is accurate. However, when the shape factor decreases as the particle size increases, the error increases. In addition, analysis results of the work efficiency and cost of the volume method and the image analysis method showed a reduction of about 80%.

• Ecology and Resilient Infrastructure
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• v.7 no.2
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• pp.83-89
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• 2020

This hydraulic study analyzed the scour effect at fixed downstream weirs based on the changes in the upstream bed slope. The study was performed using six different bed slopes, that is, 0%, 2%, 3%, 4%, 7%, and 10% at 0.117 ㎥/s in all cases. The scour depth, scour length, and scour volume were measured using a broadband laser scanner to quantitatively analyze the scour at the downstream weir. This study also examined the adequacy of the designed apron length by comparatively analyzing the results of the scour experiments and the apron length calculated using conventional design standard formulas. The analysis of the local scour effect at the downstream weir showed that scour length and scour depth increased as the bed slope became steeper. A comparison between the results of the scour experiment and that of the conventional design formulas showed that both formulas of the National Construction Research Institute and the Bligh were distributed within the allowable values when there was no upstream bed slope. However, as the bed slope upstream of the weir gradually increased, the scour lengths of the apron deviated slightly from the values obtained from the conventional design formulas.

• KSBB Journal
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• v.22 no.2
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• pp.102-108
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• 2007

A sewage was treated using a vertical flow zeolite-filled reed bed. The sewage from the student dormitory of Changwon National University was fed into the reed bed for 10 minutes every 6 hours at the hydraulic load of $314L/m^3{\cdot}$day. The filtering height of the reed bed was 100 em and the zeolite mixture was filled in the reed bed. The mixture consisted of the same volume of two types of zeolite: 0.5$\sim$1 mm and 1$\sim$3 mm in diameter. Annual average removal efficiency was 88 89.9%, $COD_{Cr}$ 86.1 %, $COD_{Mn}$ 81.2%, T-N 34.0%, $NH_4^+$-N 97.3% and T-P 34.6%. T-N of effluent was mostly $NO_3^-$-N and the concentration of $NO_2^-$-N in effluent was lower than 0.1 mg/L. All removal efficiencies did not show a remarkable seasonal change. The ranking of phosphorous fractions fixed to the zeolite in column test was Ca-P > Fe-P > reductant soluble Fe-P > occluded P > saloid P > AI-P at all depths of the filter. All phosphorous fractions except for AI-P reduced at deeper filter layer, while their content ratios increased at deeper filter layer. Organic matter content was the highest at the highest layer (0$\sim$5 cm from the top of the filter) and only small differences were observed at the deeper filter layer than 5 em from the top. Organic matter content increased at all depths of the filter with the operating time.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.2
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• pp.123-130
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• 2015

For the analysis of ⁹⁰Sr, which is a pure beta emitter, radiochemical separation from the main interfering elements such as Ca, Ba and Ra is required due to their similarity in chemical behavior to strontium. This study describes a radioanalytical procedure using extraction chromatography for separating Sr from interfering elements. The maximum capacity of the resin for Sr was approximately 6 mg per 1.5 mL of bed volume (BV). The recovery of Sr on the resin 1.5 mL (BV) was quantitative for the calcium level of 200 mg at the flow rate of 1 mL min^-1. However the chemical yield declined by increasing the flow rate by up to 5 mL min^-1 even at the calcium level of 200 mg. When using the same BV of Sr resin, the performance of the resin was enhanced as the cross-sectional area of the Sr resin column is small.