• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.386-390
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• 2005

This study was conducted to develop the biofilter fur reducing ammonia $(NH_3)$ and hydrogen sulfide $(H_2S)$ gas emission from a pig house. A biofilter was designed and constructed by a type of squeeze air into the column type of air flow upward. Its column size was ${\Phi}260{\times}360mm$. It was used pressure drop gauge, turbo blower, air temperature, velocity sensor and control program that was programed by LabWindows CVI 5.5. Mixing materials were consisted with composted pine tree bark and perlite with 7:3 ratio (volume). The biofilter media inoculated with ammonia (Rhodococcus equi A3) and hydrogen sulfide (Alcaligenes sp. S5-5.2) oxidizing microorganisms was installed in a commercial pig house to analyzed the effectiveness of biogas removal for 10 days. Removal rates of ammonia and hydrogen sulfide gases were 90.8% and 81.5%, respectively. This result suggests that the pine compost-perlite mixture biofilter is effective and economic for reducing ammonia ana hydrogen sulfide gases.

• Journal of Conservation Science
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• v.17 s.17
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• pp.83-94
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• 2005

Host rock or the standing sculptured Buddha in the Yongamsa temple is macular porphyritic biotite granite, which has gone through mechanical and chemical weathering. The rock around the Buddha statue is busily scattered with steep inclinations that are almost vertically discontinuous planes with the strikes of $N8^{\circ}E$. Especially the development of the joints that cross the major joints causes the structural instability of the rock. The rock of the Buddha statue is separated into several rock blocks because of many different discontinuity. Thus it is estimated that the bed rock has not only plane and toppling failure but also wedge failure in all the sides. Since the differential pressure is imposed on the body of the Buddha in the host rock, it is urgent to give a reinforce treatment of geotechnical engineering for the safe of its structural stability. Very contact area of joints have turned into soil, which promotes the growth of weeds and plant roots, then aggravates the mechanical weathering of the rock. Thus conservational treatments should also be considered to get rid of secondary contaminants and vegetation along the discontinuities and to prevent further damages.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.865-875
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• 2018

Selection of optimum reaction conditions during deoxygenation process of palm oil is essential factor to obtain the maximum yield of bio-jet fuel. In this context, the deoxygenation of palm oil was carried out in a fixed bed reactor with an internal diameter of 1 inch loaded with a 1 wt.% $Pt/Al_2O_3$ catalyst. The composition of the organic liquid product(OLP), which can be utilized as a transportation fuel through the upgrading process, was analyzed by a gas chromatography method. The palm oil/hydrogen ratio and hydrogen pressure in the feed affected the decarboxylation(DCB) and hydrodeoxygenation(HDO) reactions, resulting in a change in the composition of the OLP. As the reaction temperature increased, the continuous cracking reaction of the deoxygenation product was promoted and the product composition in the $C_5{\sim}C_{14}$ region was increased. Thus, the results can help to understand the characteristics of deoxidation reaction of palm oil as well as the subsequent process, hydro-upgrading, to obtain the maximum yield of bio-jet fuel.

• KSBB Journal
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• v.16 no.6
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• pp.603-608
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• 2001

In this study, we studied on the remeval of toluene vapors in a lab-scale biofilter. Biofiltration was performed in a column fed downflow with contaminated air at ambient conditions. The column was packed with mixture of Peat and Calstene(5:3 vol. Ratio), Synthesized media, Bark and Wood chip, which were inoculated with microbial population of selected stains(Pseudomonas. putida, KCCM 11343, ATCC 12633). The microorganisms were immobilized on the bed medium and then biofilm were formed. The biofilter was operated under the conditions of various inlet toluene concentrations for 180 days and treated up to the elimination capacity of maximum 40 g/㎥hr at the inlet load of 30 g/㎥ hr with percentage removals of 20∼90% and gas retention times between 1 and 2 min. The pressure drop was very negligible through the biofilter columps because its value of 0.054 cmH$_2$O/m was much less than others. The effect of operating conditions such as flow rate, inlet toluene concentration and moisture contents on the performance of the biofilter was sequentially investigated in this study.

• Journal of Hospice and Palliative Care
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• v.11 no.2
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• pp.99-105
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• 2008

Purpose: In terminally ill cancer patients, accurate prediction of survival is necessary for clinical and ethical reasons, especially in helping to avoid harm, discomfort and inappropriate therapies and in planning specific care strategies. The aim of the study was to investigate prognostic factor of dying patients. Methods: We enrolled the terminal cancer patients from Kangnam St. Mary's Hospital from 2004 until their death. We observed symptoms shown in dying patients and assess 17 common symptoms shown in terminally ill cancer patients, performance status, pain and analgesic use. Results: Average period from hospitalization to death was 11.7 days. The most important prognostic factor is performance status (KPS), average KPS at enrollment is 48% and at last 48 hours is 25%. Physical symptoms that have significant prognostic importance are poor oral intake, weakness, constipation, decreased Karnofsky performance status, bed sore, edema, jaundice, dry mouth, dyspnea. Dying patients showed markedly decreased systolic blood pressure, cyanosis, drowsiness, abnormal respiration, death rattle frequently at 48 hours before death. Conclusion: If we assess the symptoms more carefully, we can predict the more accurate prognosis. The communication about the prognostic information will influence the personal therapeutic decision and specific care planning.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.2
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• pp.87-96
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• 2017

In this study, 4 gases containing typical chlorinated volatile organic compounds (VOCs) were treated by ultraviolet (UV) irradiation. The typical chlorinated VOCs are dichloromethane (DCM), trichloromethane (TCM), carbon tetrachloride (CTC) and trichloroethylene (TCE). The removal efficiency (RE) and the products of chlorinated VOCs by UV irradiation are investigated. At this time, 2 types of background gas (air and nitrogen) were used to figure out the RE by photooxidation and photolysis. The specification of UV-lamp used in this study was low-pressure mercury lamp emitting wavelength of 185~254 nm. The experimental conditions were set as initial VOC concentration of $180{\pm}10ppm$, empty bed retention time (EBRT) of 53 s, temperature of $23{\pm}2^{\circ}C$ and relative humidity of $65{\pm}5%$. In the photolysis condition with nitrogen ($N_2$) as background gas, the averaged RE of the 4 types of chlorinated VOCs was about 24% higher than that with photooxidation; and the REs of VOCs except CTC were confirmed as >99%. The composition of off-gases after UV photooxidation in air was investigated and several intermediates from DCM, TCM and TCE were detected by GC/MS. Among them, phosgene which is a toxics was detected as an intermediate of TCM. In addition, the concentration of carbon dioxide ($CO_2$) in the off-gases was measured to calculate the mineralization rate (MR). With the photooxidation, TCE showed the highest RE (>99%) while MR was the lowest (17%); and the MR of DCM was the highest (86%). In addition, particulate matters (PM) in the off-gases was also detected and high concentrated $PM_{10}$ ($21,580{\mu}g{\cdot}m^{-3}$) and $PM_{2.5}$ ($6,346{\mu}g{\cdot}m^{-3}$) were detected in TCE off-gas. More than 99% of the chlorinated VOCs could be removed using UV254-185 nm lamp, while it is necessary to conduct further studies on the production and treatment of secondary pollutants.

• Journal of Korea Water Resources Association
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• v.41 no.8
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• pp.761-772
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• 2008

The object of this study is to develop the model that solves the numerically difficult problems in hydraulic engineering and to demonstrate the applicability of this model by means of various test examples, such as, verification in the gradually varied unsteady condition, three steady flow problems with the change of bottom slope with exact solution, and frictional bed with analytical solution. The governing equation of this model is the integral form of the Saint-Venant equation satisfying the conservation laws, and finite volume method with the Riemann solver is used. The evaluation of the mass and momentum flux with the HLL Riemann approximate solver is executed. MUSCL-Hancock scheme is used to achieve the second order accuracy in space and time. This study introduce the new and simple technique to discretize the source terms of gravity and hydrostatic pressure force due to longitudinal width variation for the balance of quantity between nonlinear flux and source terms. The results show that the developed model's implementation is accurate, robust and highly stable in various flow conditions with source terms, and this model is reliable for one-dimensional applications in hydraulic engineering.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.337-343
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• 2009

To apply to novel two-interconnected fluidized beds system for selective solid circulation, a solid separator and a solid circulation system were developed. The solid separation rate increased as the gas velocity through the solid injection nozzle, solid height, and diameter of solid injection nozzle increased. However, the effect of the fluidization velocity was negligible. Coarse($212{\sim}300{\mu}m$) and fine($63{\sim}106{\mu}m$) particles were separated using the solid separator and the solid separation rate was ranged from 66 to 453 g/min. The solid circulation rate increased as the gas velocity through the solid injection nozzle, solid height, and the number of solid intake holes increased. However, the effect of the fluidization velocity was negligible. Fine particle was circulated using the solid circulation system and the solid circulation rate was ranged from 65 to 390 g/min. We also proposed two interconnenced fluidized beds system for selective solid circulation equipped with the developed solid separator and the solid circulation system. Long-term operation of continuous solid circulation up to 20 hours has been performed to check feasibility of stable operation. The pressure drop profiles in two beds and the solid separation rate were maintained steadily, and therefore, we could conclude that solid circulation was smooth and stable.

• Membrane Journal
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• v.23 no.1
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• pp.12-23
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• 2013

On the subject of river bed water in Seomjin river, it had accomplished the verifying experiment of membrane filtration pilot plant for evaluating the applicability of its process throughout the prediction of membrane fouling as a function of the pore size of membrane and the determination of optimum coagulant dosage. On the result of the experiment for the evaluation of the membrane fouling as a function of the pore size, a increasing rate of irreversible resistance of membrane pore size $0.1{\mu}m$ and $0.01{\mu}m$ was measured each $0.44{\times}10^{12}/m^2$ and $0.42{\times}10^{12}/m^2$, respectively. And on the result of Flux-test, it showed that the optimum coagulant dosage was measured lower than the it of the Jar-test. The result to be operated in a condition of a permeate flux $1.0{\sim}1.5m^3/m^2{\cdot}day$ without coagulation and a permeate flux $1.0{\sim}2.0m^3/m^2{\cdot}day$ with coagulation was maintained at stable trans-membrane pressure (TMP) value for 6 months up to. Therefore it showed that the stable operation without the coagulation was possible on permeate flux $1.0{\sim}1.5m^3/m^2{\cdot}day$ in the operation of membrane filtration process.

• Journal of Korea Water Resources Association
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• v.41 no.2
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• pp.197-212
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• 2008

Recently, stream flow analysis has been accomplished by one or two dimensional equations and was applied by simple momentum equations and fixed energy conservations which contain many condition limits. In this study, FLOW-3D using CFD (Computational Fluid Dynamics) was applied to stream flow analysis which can solve three dimensional RANS (Reynolds Averaged Navier-Stokes Equation) control equation to find out physical behaviors and the effect of hydraulic structures. Numerical simulation accomplished those results was compared by using turbulence models such as ${\kappa}-{\varepsilon}$, RNG (Renormalized Group) ${\kappa}-{\varepsilon}$ and LES (Large Eddy Simulation). Numerical analysis results have been illustrated by the turbulence energy effects, velocity of flow, water level pressure and eddy flows around the piers and transverse overflow type structures. These results will be able to used by basis data that catch hold of effects on long-term bed elevation changes, sediment accumulations, scours and water aggravations by removal of obsolete transverse over flow type structures in urban stream.