36 results on '"Tae-Wook Ha"'
Search Results
2. Real-Time Deep Learning-Based Anomaly Detection Approach for Multivariate Data Streams with Apache Flink.
- Author
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Tae Wook Ha, Jung Mo Kang, and Myoung Ho Kim
- Published
- 2021
- Full Text
- View/download PDF
3. Efficient Searching of Subhypergraph Isomorphism in Hypergraph Databases.
- Author
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Tae Wook Ha, Jung Hyuk Seo, and Myoung Ho Kim
- Published
- 2018
- Full Text
- View/download PDF
4. Carbon-ion radiotherapy in osteosarcoma of the mandible: a case report
- Author
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Tae-Wook Ha, Min Yeong Youn, Dongwook Kim, Slmaro Park, and Hyungjun Kim
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Osteosarcoma ,medicine.medical_specialty ,Chemotherapy ,Radiotherapy ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,Mandible ,Case Report ,Magnetic resonance imaging ,Heavy Ion Radiotherapy ,medicine.disease ,Head and neck neoplasms ,Radiation therapy ,Biological property ,medicine ,Carbon Ion Radiotherapy ,Heavy ion radiotherapy ,Surgery ,Radiology ,Oral Surgery ,business - Abstract
Carbon-ion radiotherapy (CIRT) is on the rise as a treatment choice for malignant tumor. Compared to conventional radiotherapy, particle beams have different physical and biological properties. Particle beam provides a low entry dose, deposits most of the energy at the endpoint of the flight path, and forms an asymptotic dose peak (the “Bragg peak”). Compared to protons, carbon with its larger mass decreases beam scattering, resulting in a sharper dose distribution border. We report a 50-year-old male who underwent CIRT without surgical resection on osteosarcoma of the mandible. After CIRT, the patient’s pain was gone, and the malignant mass remained stable with accompanying necrosis. Nine months later, however, magnetic resonance imaging demonstrated progression of the left mandibular osteosarcoma with pulmonary metastases. After multidisciplinary discussion, concurrent chemoradiotherapy was conducted. While necrotic bone segments came out of the mandible during subsequent periodic outpatient visits, the tumor itself was stable. Thirty months after his first visit and diagnosis, the patient is waiting for chemotherapy. Although CIRT is superior in treating radioresistant hypoxic disease, CIRT is in its infancy, so care must be taken for its indications and complications.
- Published
- 2021
5. Thermal analysis of the oil cooling motor according to the churning phenomenon
- Author
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Nyeon Gu Han, Hae Lee Lee, Ryang Hoon Kim, Tae Young Beom, Young Kyo Kim, Tae Wook Ha, Sung Wook Lee, and Dong Kyu Kim
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Energy Engineering and Power Technology ,Industrial and Manufacturing Engineering - Published
- 2023
6. Thermal Analysis of the Oil Cooling Efficiency of a Motor According to the Churning Phenomenon
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Nyeon Gu Han, Hae Lee Lee, Tae Wook Ha, Sung Wook Lee, and Dong Kyu Kim
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History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
7. Solitary Lymphomatoid Granulomatosis at the Maxilla
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Dongwook Kim, Hussain I Al-Fadhel, Eunae Sandra Cho, Tae-Wook Ha, Woo Ick Yang, and Dawool Han
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medicine.medical_specialty ,Lymphomatoid granulomatosis ,business.industry ,Maxilla ,Medicine ,business ,medicine.disease ,Dermatology - Published
- 2019
8. Plant-expressed Zika virus envelope protein elicited protective immunity against the Zika virus in immunocompetent mice
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Minna Shin, Hyangju Kang, Kyeong ryeol Shin, Rangyeon Lee, Kiju Kim, Kyungmin Min, Kyou-Nam Cho, Eun-Ju Sohn, Kwang Sung Kim, Seok-Hyun Kim, Yang Je Cho, Jeongho Park, and Tae-Wook Hahn
- Subjects
Medicine ,Science - Abstract
Abstract Zika virus infection causes multiple clinical issues, including Guillain–Barré syndrome and neonatal malformation. Vaccination is considered as the only strategy for the prevention of ZIKV-induced clinical issues. This study developed a plant-based recombinant vaccine that transiently expressed the ZIKV envelope protein (ZikaEnv:aghFc) in Nicotiana benthamiana and evaluated the protective immunity afforded by it in immunocompetent mice. ZikaEnv:aghFc induced both humoral and cellular immunity at a low dose (1–5 μg). This immune-inducing potential was enhanced further when adjuvanted CIA09A. In addition, antigen-specific antibodies and neutralizing antibodies were vertically transferred from immunized females to their progeny and afforded both protective immunity to ZIKV and cross-protection to Dengue virus infection. These results suggest that our plant-based ZIKV vaccine provides a safe and efficient protective strategy with a competitive edge.
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- 2023
- Full Text
- View/download PDF
9. Index-based Searching for Isomorphic Subgraphs in Hypergraph Databases
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Jung Hyuk Seo, Myoung Ho Kim, Tae Wook Ha, and Dae Geun Ha
- Subjects
Combinatorics ,Hypergraph ,Index (economics) ,Graph (abstract data type) ,Structural index ,Mathematics - Published
- 2019
10. Improvement of the MARS subcooled boiling model for a vertical upward flow
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Byong-Jo Yun, Tae-Wook Ha, and Jae Jun Jeong
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geography ,geography.geographical_feature_category ,020209 energy ,Flow (psychology) ,02 engineering and technology ,Mars Exploration Program ,Mechanics ,Inlet ,lcsh:TK9001-9401 ,030218 nuclear medicine & medical imaging ,Subcooling ,03 medical and health sciences ,0302 clinical medicine ,Nuclear Energy and Engineering ,Liquid velocity ,Boiling ,0202 electrical engineering, electronic engineering, information engineering ,lcsh:Nuclear engineering. Atomic power ,Environmental science ,Hydraulic diameter ,Porosity - Abstract
In the thermal-hydraulic system codes, such as MARS and RELAP5/MOD3, the Savannah River Laboratory (SRL) model has been adopted as a subcooled boiling model. It, however, has been shown that the SRL model cannot take into account appropriately the effects of inlet liquid velocity and hydraulic diameter on axial void fraction development. To overcome the problems, Ha et al. (2018) proposed a modified SRL model, which is applicable to low-pressure and low-Pe conditions (P
- Published
- 2019
11. Improvement of the MARS subcooled boiling model for low-pressure, low-Pe flow conditions
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Byong-Jo Yun, Tae Wook Ha, Han Young Yoon, and Jae Jun Jeong
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Materials science ,020209 energy ,Evaporation ,02 engineering and technology ,Mars Exploration Program ,Péclet number ,Mechanics ,Subcooling ,symbols.namesake ,Flow conditions ,Nuclear Energy and Engineering ,Boiling ,0202 electrical engineering, electronic engineering, information engineering ,symbols ,Hydraulic diameter ,Porosity - Abstract
The subcooled boiling model of a thermal-hydraulic system code, MARS, has been assessed against subcooled boiling experiments in vertical pipes under low-pressure and low-Pe (Peclet number) conditions. The results showed that the MARS subcooled boiling model cannot take into account appropriately the effects of inlet liquid velocity and hydraulic diameter on axial void fraction development. To solve the problems, a new correlation for the net vapor generation (NVG) point is suggested and the wall evaporation model, which is one of the sub-models of the subcooled boiling model, has been semi-empirically modified. The modified models were implemented into MARS and validated using experimental data of 77 different thermal-hydraulic conditions with pressures ranging from 1.1 to 9.8 bar, heat fluxes of 97–1186 kW/m2, mass fluxes of 65–635 kg/m2 s, and hydraulic diameters of 5–21 mm. It was shown that the results of the modified model have better agreements with experimental data under low-pressure (P
- Published
- 2018
12. Purification of wastewater from paper factory by superconducting magnetic separation
- Author
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Dong-Woo Ha, Tae-Hyung Kim, Myung-Hwan Sohn, Jun-Mo Kwon, Seung-Kyu Baik, Rock-Kil Ko, Sang-Soo Oh, Hong-Soo Ha, Ho-Sup Kim, Young-Hun Kim, and Tae-Wook Ha
- Subjects
Bismuth -- Magnetic properties ,Bismuth -- Electric properties ,Paper industry -- Waste management ,Superconducting magnets -- Usage ,Water -- Purification ,Water -- Innovations ,Business ,Electronics ,Electronics and electrical industries - Published
- 2010
13. A porcine circovirus type 2d-based virus-like particle vaccine induces humoral and cellular immune responses and effectively protects pigs against PCV2d challenge
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Kiju Kim, Kyusung Choi, Minna Shin, and Tae-Wook Hahn
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porcine circovirus ,virus-like particles ,PCV2d-based vaccine ,miniature pig ,protective immunity ,Microbiology ,QR1-502 - Abstract
The pathogenic porcine circovirus type 2 (PCV2) leads to significant economic losses in pig production. PCV2d is currently the dominant genotype causing porcine circovirus-associated disease (PCVAD) worldwide. Therefore, development of a recombinant PCV2d-based vaccine is required to elicit complete protection against PCV2d infection. In this study, we generated virus-like particles of PCV2d-based capsid protein (Bac-2dCP) using a baculovirus expression system and evaluated its protective efficacy against PCV2d infection in specific pathogen-free (SPF) pigs. Three-week-old SPF miniature pigs were intramuscularly immunized with purified Bac-2dCP and intranasally challenged with PCV2d at 4 weeks post-vaccination. The Bac-2dCP group showed significantly higher IgG levels and neutralizing antibodies against PCV2b and PCV2d genotypes, as well as increased interferon-γ levels, and increased body weight and average daily weight gain compared with positive (challenged) and negative (unchallenged) controls. In particular, the Bac-2dCP group showed almost complete absence of PCV2d DNA in serum, nasal, and rectal swabs and in lung, lymph node, and kidney tissue samples. However, the positive control group exhibited low levels of neutralizing antibody, and high levels of PCV2 DNA in serum, swab, and tissue samples, resulting in PCV2-associated pathological lesions. The results of this study demonstrated that a recombinant Bac-2dCP vaccine conferred complete protection against a PCV2d challenge in SPF miniature pigs.
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- 2024
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14. Development of an empirical correlation for the onset of flow instability in narrow rectangular channels
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Jong-Pil Park, Sung Won Bae, Jae Jun Jeong, Byong-Jo Yun, Daeseong Jo, and Tae Wook Ha
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Mass flux ,Physics ,Nuclear and High Energy Physics ,020209 energy ,Mechanical Engineering ,Ranging ,02 engineering and technology ,Mechanics ,01 natural sciences ,010305 fluids & plasmas ,Correlation ,Flow instability ,Diameter ratio ,Nuclear Energy and Engineering ,Heat flux ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Range (statistics) ,General Materials Science ,Development (differential geometry) ,Safety, Risk, Reliability and Quality ,Waste Management and Disposal - Abstract
An empirical correlation has been developed to accurately predict the onset of flow instability (OFI) in narrow rectangular channels under a wide thermal–hydraulic condition. The 242 sets of OFI experiments were collected, which cover a wide range of thermal–hydraulic conditions with pressures ranging from 0.103 to 1.73 MPa, a heat flux ranging from 0.1 to 16.8 MW/m2, a mass flux ranging from 151 to 20,325 kg/m2·s, Pe ranging from 6650 to 358,460, and Pr ranging from 0.94 to 3.17. The test sections have gap sizes between 1.27 and 3.6 mm, hydraulic diameters between 2.37 and 6.58 mm, and a length-to-heated diameter ratio between 82.3 and 197.5. The collected experimental data were analyzed to find out the effects of parameters on the OFI. From the analysis, non-dimensional numbers affecting the OFI point were determined and an empirical correlation was developed. The new empirical correlation as well as several existing net vapor generation (NVG) and OFI correlations were assessed against the OFI experimental data. It was shown that the proposed correlation provides agreements with the experimental OFI points than the other correlations.
- Published
- 2021
15. Modification of the fast fourier transform-based method by signal mirroring for accuracy quantification of thermal-hydraulic system code
- Author
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Ki-Yong Choi, Jae Jun Jeong, and Tae Wook Ha
- Subjects
Computer science ,020209 energy ,Fast Fourier Transform-Based Method by Signal Mirroring ,Frequency-Dependent Evaluation ,Fast Fourier transform ,Experimental data ,02 engineering and technology ,lcsh:TK9001-9401 ,Signal ,Cutoff frequency ,Thermal hydraulics ,Nuclear Energy and Engineering ,Cut-Off Frequency ,0202 electrical engineering, electronic engineering, information engineering ,Code (cryptography) ,lcsh:Nuclear engineering. Atomic power ,Cut-off ,Spurious relationship ,Algorithm - Abstract
A thermal–hydraulic system code is an essential tool for the design and safety analysis of a nuclear power plant, and its accuracy quantification is very important for the code assessment and applications. The fast Fourier transform-based method (FFTBM) by signal mirroring (FFTBM-SM) has been used to quantify the accuracy of a system code by using a comparison of the experimental data and the calculated results. The method is an improved version of the FFTBM, and it is known that the FFTBM-SM judges the code accuracy in a more consistent and unbiased way. However, in some applications, unrealistic results have been obtained. In this study, it was found that accuracy quantification by FFTBM-SM is dependent on the frequency spectrum of the fast Fourier transform of experimental and error signals. The primary objective of this study is to reduce the frequency dependency of FFTBM-SM evaluation. For this, it was proposed to reduce the cut off frequency, which was introduced to cut off spurious contributions, in FFTBM-SM. A method to determine an appropriate cut off frequency was also proposed. The FFTBM-SM with the modified cut off frequency showed a significant improvement of the accuracy quantification.
- Published
- 2017
16. Improvement of the subcooled boiling model for thermal–hydraulic system codes
- Author
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Jae Jun Jeong, Tae-Wook Ha, and Byong-Jo Yun
- Subjects
Nuclear and High Energy Physics ,Void (astronomy) ,Materials science ,020209 energy ,Mechanical Engineering ,02 engineering and technology ,Mechanics ,01 natural sciences ,010305 fluids & plasmas ,Thermal hydraulics ,Subcooling ,Pressure range ,Nuclear Energy and Engineering ,Liquid velocity ,Boiling ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,General Materials Science ,Safety, Risk, Reliability and Quality ,Waste Management and Disposal - Abstract
In thermal–hydraulic system codes, such as MARS and RELAP5/MOD3, the Savannah River Laboratory (SRL) model has been used as a subcooled boiling model for recent two decades. However, it has been known that the SRL model cannot properly capture the effects of liquid velocity and channel diameter on the development of axial void profile. The authors suggested the modifications of the SRL model in the previous studies, focusing on the net vapor generation model and the wall vapor generation model, and validated the modified model using 103 subcooled boiling experiments, of which pressures were limited up to 69 bar. In this work, the previous subcooled boiling model has been further improved for its extension to high-pressure conditions up to ∼ 150 bar using additional 42 sets of high-pressure experiments. The new model has been validated against a wide range of experiments. It was shown that the new model predicts axial void fractions better than the SRL model and the previous model for the whole pressure range and that it can completely replace the SRL model without any limitation.
- Published
- 2020
17. Vaccination with a Zika virus envelope domain III protein induces neutralizing antibodies and partial protection against Asian genotype in immunocompetent mice
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Minna Shin, Kiju Kim, Hyo-Ji Lee, Yu-Jin Jung, Jeongho Park, and Tae-Wook Hahn
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Zika virus ,Infectious diseases ,Disease prevention ,Arctic medicine. Tropical medicine ,RC955-962 - Abstract
Abstract Background Zika virus (ZIKV) is a mosquito-borne flavivirus classified in Flaviviridae family such as dengue (DENV), yellow fever, and West Nile virus. An outbreak of ZIKV infection can pose a major public health risk because the contagion is unpredictable and induces severe pathology such as Guillan-Barre syndrome and neonatal microcephaly. However, an authorized ZIKV vaccine is not yet available, while several vaccine candidates are under development. Methods In this study, we constructed a recombinant ZIKV vaccine (Z_EDIII) that includes ZIKV envelope protein domain III using E. coli expression system. Then both humoral and cellular immunity were examined in C57BL/6 (female, 8-weeks-old) mice via Indirect ELISA assay, PRNT, ELISpot and cytokine detection for IFN-γ, TNF-α, and IL-12. In addition, the cross protection against DENV was evaluated in pups from Z_EDIII vaccinated and infected dam. Results Mice immunized by Z_EDIII produced a significant amount of ZIKV EDIII-specific and neutralizing antibodies. Together with antibodies, effector cytokines, such as IFN-γ, TNF-α, and IL-12 were induced. Moreover, vaccinated females delivered the adaptive immunity to neonates who are protective against ZIKV and DENV challenge. Conclusions This study observed Z-EDIII-induced humoral and cellular immunity that protected hosts from both ZIKV and DENV challenges. The result suggests that our ZIKV EDIII recombinant vaccine has potential to provide a new preventive strategy against ZIKV infection.
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- 2022
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18. The MARS Simulation of the ATLAS Main Steam Line Break Experiment
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Jae Jun Jeong, Tae Wook Ha, and Byong-Jo Yun
- Subjects
Engineering ,Secondary side ,System code ,business.industry ,Nuclear engineering ,Heat transfer ,Boiler (power generation) ,Polygon mesh ,Mars Exploration Program ,Steam line ,business ,Standard problem ,Simulation - Abstract
A main steam line break (MSLB) test at the ATLAS facility was simulated using the best-estimate thermal-hydraulic system code, MARS-KS. This has been performed as an activity at the third domestic standard problem for code benchmark (DSP-03) that has been organized by Korea Atomic Energy Research Institute (KAERI). The results of the MSLB experiment and the MARS input data prepared for the previous DSP-02 using the ATLAS facility were provided to participants. The preliminary MSLB simulation using the base input data, however, showed unphysical results in the primary-to-secondary heat transfer. To resolve the problems, some improvements were implemented in the MARS input modelling. These include the use of fine meshes for the bottom region of the steam generator secondary side and proper thermal-hydraulics calculation options. Other input model improvements in the heat loss and the flow restrictor models were also made and the results were investigated in detail. From the results of simulations, the limitations and further improvement areas of the MARS code were identified.
- Published
- 2014
19. Characterization of Inflammasomes and Their Regulation in the Red Fox
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Huijeong Ahn, Dong-Hyuk Jeong, Gilyoung Lee, Suk-Jin Lee, Jeong-Jin Yang, Yo-Han Kim, Tae-Wook Hahn, Sooyoung Choi, and Geun-Shik Lee
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red foxes ,Vulpes vulpes ,inflammasome ,cytokine ,interleukin-1beta ,Veterinary medicine ,SF600-1100 ,Zoology ,QL1-991 - Abstract
Background: Inflammasomes recognize endogenous and exogenous danger signals, and subsequently induce the secretion of IL-1β. Studying inflammasomes in the red fox (Vulpes vulpes) is crucial for wildlife veterinary medicine, as it can help control inflammatory diseases in foxes. Methods: We investigated the activation and intracellular mechanisms of three inflammasomes (NLRP3, AIM2, and NLRC4) in fox peripheral blood mononuclear cells (PBMCs), using established triggers and inhibitors derived from humans and mice. Results: Fox PBMCs exhibited normal activation and induction of IL-1β secretion in response to representative inflammasome triggers (ATP and nigericin for NLRP3, dsDNA for AIM2, flagellin for NLRC4). Additionally, PBMCs showed normal IL-1β secretion when inoculated with inflammasome-activating bacteria. In inhibitors of the inflammasome signaling pathway, fox inflammasome activation was compared with mouse inflammasomes. MCC950, a selective NLRP3 inhibitor, suppressed the secretion of dsDNA- and flagellin-mediated IL-1β in foxes, unlike mice. Conclusions: These findings suggest that NLRP3 may have a common role in dsDNA- and flagellin-mediated inflammasome activation in the red fox. It implies that this fox inflammasome biology can be applied to the treatment of inflammasome-mediated diseases in the red fox.
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- 2023
- Full Text
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20. Stabilization of Hydrogen Peroxide using Malonic Acid in Fenton and Fenton-like reactions
- Author
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Young-Hun Kim, Jee-Eun Kim, and Tae-Wook Ha
- Subjects
inorganic chemicals ,Hydrogen ,Groundwater remediation ,Inorganic chemistry ,chemistry.chemical_element ,Malonic acid ,Hematite ,Peroxide ,Catalysis ,chemistry.chemical_compound ,chemistry ,visual_art ,visual_art.visual_art_medium ,Hydrogen peroxide ,Stabilizer (chemistry) - Abstract
Hydrogen peroxide takes much of the cost for Fenton reaction applied for treatment of organic contaminants. Therefore,the effective use of hydrogen peroxide makes the technology more cost effective. The effective use of hydrogen peroxideis especially needed in the soil and groundwater remediation where complete mixing is not possible and it takes a longtime for reactive species to transport to the fixed target compounds. Stabilization ability for hydrogen peroxide of malonicacid was evaluated in Fenton and Fenton-like reactions in this study. Malonic acid contributes on the stabilization ofhydrogen peroxide by weak interaction between iron and the stabilizer and inhibiting the catalytic role of iron. Thestabilization effect increased as the solution pH decrease below the pK a1 . The stabilization effect increased as theconcentration of malonic acid increased and the effect was maximized at the malonic acid concentration of about ten timeshigher than the iron concentration. The model organic contaminant was successfully oxidized in the presence of thestabilizer but the degradation rate was slower than the system without the stabilizer. The stabilization effect was alsoproved in a Fenton-like reaction where magnetite and hematite were used instead of soluble iron species.Key words :Fenton oxidation, Fenton-like reactions, Stabilization, Life-time, Malonic acid
- Published
- 2013
21. Purification of Wastewater From Paper Factory by Superconducting Magnetic Separation
- Author
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Jun-Mo Kwon, Dong-Woo Ha, Tae-Wook Ha, Ho-Sup Kim, Seung-Kyu Baik, Myung-Hwan Sohn, Rock-Kil Ko, Young-Hun Kim, Hong-Soo Ha, Sang-Soo Oh, and Tae-Hyung Kim
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Superconductivity ,Materials science ,Metallurgy ,Magnetic separation ,Superconducting magnet ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Volumetric flow rate ,chemistry.chemical_compound ,Nuclear magnetic resonance ,Wastewater ,chemistry ,Water treatment ,Sewage treatment ,Electrical and Electronic Engineering ,Magnetite - Abstract
It is environmentally important to recycle the wastewater, since paper factories use a large amount of water and equivalent amount of wastewater is generated. Conventional water treatment facilities like precipitation process need large-scale equipment and wide space to purify the wastewater of paper factory. In case of massive waste water, high gradient magnetic separation (HGMS) parts are more effective to purify it rapidly and to occupy relatively small space, since large voids at filter with HGMS are adopted. In this respect, we prepared two types of superconducting magnets in order to apply HGMS parts for wastewater purification process. We made cryo-cooled Bi-2223 (HTS) superconducting magnet parts with room temperature bore in diameter of 70 mm and 200 mm in height. Also, cryo-cooled Nb-Ti superconducting magnet with room temperature bore in diameter of 100 mm and 600 mm in height was used for magnetic separator. Magnetic filters were designed by the analysis of magnetic field distribution at superconducting magnets. The faster wastewater's flow rate was, the worse the degree of clarity in treated water was. The ability of wastewater treatment in the case of magnetic separation used with 10 of magnetite particles was better than that in the case of 5 of magnetite particles.
- Published
- 2010
22. Intergenerational Income Elasticity in Korea
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Bonggeun Kim, Tae-wook Ha, and Minseong Kim
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Labour economics ,Economics ,Income elasticity of demand - Published
- 2009
23. Decolorization of reactive dyes using inorganic coagulants and synthetic polymer
- Author
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Won Sik Shin, Sang June Choi, Myung Ho Han, Duk Jong Joo, Myung-Chul Kim, Tae Wook Ha, Young-Hun Kim, and Jeong-Hak Choi
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chemistry.chemical_classification ,Flocculation ,Chromatography ,Chemistry ,Alum ,Process Chemistry and Technology ,General Chemical Engineering ,Salt (chemistry) ,chemistry.chemical_compound ,Wastewater ,medicine ,Ferric ,Reactive dye ,Coagulation (water treatment) ,Dyeing ,medicine.drug ,Nuclear chemistry - Abstract
A coagulation/flocculation process was employed for the treatment of high concentration reactive dye wastewater. A polymer flocculant synthesized from cyanoguanidine and formaldehyde under acidic conditions was applied with inorganic coagulant (alum or ferric salt) for the dyeing wastewater. The flocculant was tested for synthetic wastewater containing four model reactive dyes (Black 5, Blue 2, Red 2 and Yellow 2) and real wastewater containing reactive dyes from a local dyeing industry. For the synthetic wastewater, the use of inorganic coagulant (1 g/L) alone achieved only 20% of color removal or less. However, with the aid of polymer flocculant, almost 100% of color removal was obtained. The dye removal efficiency increased as polymer dose increased and the efficiency was affected by solution pH and types of the used inorganic coagulant. The use of inorganic coagulant alone appeared little effective in the removal of reactive dyes from the real wastewater. However, alum/polymer and ferric salt/polymer combinations improved color removal up to 60% and 40%, respectively.
- Published
- 2007
24. Zika virus baculovirus-expressed envelope protein elicited humoral and cellular immunity in immunocompetent mice
- Author
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Minna Shin, Kiju Kim, Hyo-Ji Lee, Rangyeon Lee, Yu-Jin Jung, Jeongho Park, and Tae-Wook Hahn
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Medicine ,Science - Abstract
Abstract Zika virus (ZIKV) is a mosquito-borne virus that has a high risk of inducing Guillain–Barré syndrome and microcephaly in newborns. Because vaccination is considered the most effective strategy against ZIKV infection, we designed a recombinant vaccine utilizing the baculovirus expression system with two strains of ZIKV envelope protein (MR766, Env_M; ZBRX6, Env_Z). Animals inoculated with Env_M and Env_Z produced ZIKV-specific antibodies and secreted effector cytokines such as interferon-γ, tumor necrosis factor-α, and interleukin-12. Moreover, the progeny of immunized females had detectable maternal antibodies that protected them against two ZIKV strains (MR766 and PRVABC59) and a Dengue virus strain. We propose that the baculovirus expression system ZIKV envelope protein recombinant provides a safe and effective vaccine strategy.
- Published
- 2022
- Full Text
- View/download PDF
25. Magnetic behaviors of MnxFe3−xO4 thin films grown by ferrite plating method
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Ill Won Kim, Jung Hyun Jeong, Soung Soo Yi, Jeong Sik Lee, and Tae Wook Ha
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Materials science ,Metallurgy ,Spinel ,Metals and Alloys ,Surfaces and Interfaces ,Coercivity ,Atmospheric temperature range ,engineering.material ,Grain size ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Magnetization ,Materials Chemistry ,engineering ,Ferrite (magnet) ,Crystallite ,Thin film ,Composite material - Abstract
We have performed ferrite plating of MnxFe3−xO4 (x=0.016, 0.028, 0.049, 0.066 and 0.090) films grown on the cover glass at substrate temperature range 75–90 °C and the fixed pH of the oxidizing solution, 7.1. The deposition rate and the saturated magnetization of thin film increased with the substrate temperature and X-ray diffraction (XRD) patterns of the films showed a single phase of polycrystalline spinel structure. The highest value, 506, of the saturation magnetization was obtained in the MnxFe3−xO4 film made at the substrate temperature 85 °C. The thickness and grain size of the film increased with the substrate temperature. On the other hand, the coercive force decreased with the increase of thickness and grain size of the film.
- Published
- 2005
26. Magnetic behavior of MnxZn0.22Fe2.78?xO4 (x = 0.00-0.08) thin films grown by ferrite plating method
- Author
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Jeong Sik Lee, Ill Won Kim, Soung Soo Yi, Jung Hyun Jeong, and Tae Wook Ha
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Diffraction ,Chemistry ,Doping ,Metallurgy ,Spinel ,Analytical chemistry ,engineering.material ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Magnetization ,Lattice constant ,engineering ,Ferrite (magnet) ,Crystallite ,Thin film - Abstract
Ferrite plating of Mn x Zn 0.22 Fe 2.78-x O 4 (x = 0.00-0.08) films grown on cover glass at a substrate temperature of 90 °C was performed. X-ray diffraction patterns of the films showed a single phase of polycrystalline spinel structure. The calculated lattice constants of Mn x Zn 0.22 Fe 2.78-x O 4 films with x = 0.00 and 0.08 were a = 8.416 and 8.427 A, respectively. The deposition rate monotonically decreased as the concentration of Mn 2+ in the reaction solution increased. As the Mn concentration increased from x = 0.00 to 0.08, the saturation magnetization (M s ) decreased from 419 to 394 emu/cm 3 .
- Published
- 2004
27. Removal of Ammonia by Biofilters: A Study with Flow-Modified System and Kinetics
- Author
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Duk Jong Joo, Tae Wook Ha, Jeong Hak Choi, Sang June Choi, Dal Hoon Lee, In Ho Park, Young Hun Kim, and Yun Seok Jeong
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Air Movements ,Chromatography ,Compost ,Kinetics ,Management, Monitoring, Policy and Law ,Biodegradation ,engineering.material ,Pulp and paper industry ,Ammonia ,chemistry.chemical_compound ,Bioreactors ,chemistry ,Air Pollution ,Odorants ,Biofilter ,Bioreactor ,engineering ,Perlite ,Organic Chemicals ,Saturation (chemistry) ,Waste Management and Disposal ,Filtration - Abstract
The characteristics of ammonia removal by two types of biofilter (a standard biofilter with vertical gas flow and a modified biofilter with horizontal gas flow) were investigated. A mixture of organic materials such as compost, bark, and peat was used as the biofilter media based on the small-scale column test for media selection. Complete removal capacity, defined as the maximum inlet load of ammonia that was completely removed, was obtained. The modified biofilter showed complete removal up to 1.0 g N/kg dry material/day. However, the removal capacity of the standard biofilter started to deviate from complete removal around 0.4 g N/kg dry material/day, indicating that the modified biofilter system has higher removal efficiency than the standard upflow one. In kinetic analysis of the biological removal of ammonia in each biofilter system, the maximum removal rate, Vm, was 0.93 g N/kg dry material/day and the saturation constant, Ks, was 32.55 ppm in the standard biofilter. On the other hand, the values of Vm and Ks were 1.66 g N/kg dry material/day and 74.25 ppm, respectively, in the modified biofilter system.
- Published
- 2003
28. Effect of chlorine on adsorption/ultrafiltration treatment for removing natural organic matter in drinking water
- Author
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Sang-June Choi, Tae-Wook Ha, and Kwang-Ho Choo
- Subjects
chemistry.chemical_classification ,Powdered activated carbon treatment ,Chromatography ,Membrane permeability ,Ultrafiltration ,chemistry.chemical_element ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,Biomaterials ,Colloid and Surface Chemistry ,Adsorption ,chemistry ,law ,Environmental chemistry ,polycyclic compounds ,Chlorine ,Organic matter ,Water treatment ,Filtration - Abstract
In drinking water treatment, prechlorination is often applied in order to control microorganisms and taste-and-odor-causing materials, which may influence organics removal by adsorption and membrane filtration. Thus, the addition of chlorine into an advanced water treatment process using a hybrid of adsorption and ultrafiltration (UF) was investigated in terms of natural organic matter (NOM) removal and membrane permeability. A comparison between two adsorbents, iron oxide particles (IOP) and powdered activated carbon (PAC), was made to understand the sorption behavior for NOM with and without chlorination. Chlorine modified the properties of dissolved and colloidal NOM in raw water, which brought about lower TOC removal, during IOP/UF. The location of IOPs, whether they were in suspension or in a cake layer, affected NOM removal, depending on the presence of colloidal particles in feedwater. Chlorine also played a role in reducing the size of particulate matter in raw water, which could be in close association with a decline in permeate flux after chlorination.
- Published
- 2003
29. Management of choroidal neovascularization following laser photocoagulation for central serous chorioretinopathy
- Author
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Se Woong Kang, Tae Wook Ha, and Don Il Ham
- Subjects
Adult ,Male ,medicine.medical_specialty ,Visual acuity ,genetic structures ,Light ,Treatment outcome ,Visual Acuity ,Diagnostic Techniques, Ophthalmological ,Retinal Diseases ,Submacular surgery ,Ophthalmology ,medicine ,Humans ,Tomography ,Laser Coagulation ,business.industry ,Laser treatment ,General Medicine ,Choroid Diseases ,eye diseases ,Choroidal Neovascularization ,Serous fluid ,Choroidal neovascularization ,Interferometry ,Treatment Outcome ,Female ,sense organs ,medicine.symptom ,Complication ,business - Abstract
Little is known about the natural history and management of choroidal neovascularization (CNV) which developed as a complication of laser photocoagulation for central serous chorioretinopathy (CSC). We experienced two patients with CNV which developed after laser treatment for CSC. Submacular membranectomy was performed on both cases after the confirmation of subretinal CNV with optical coherence tomography. One patient received photodynamic therapy for recurrent CNV. The vision of both patients has been improved over 6 months of follow up. These cases suggest that active intervention, including submacular surgery, improves the visual prognosis of this condition.
- Published
- 2003
30. Evaluation of Salmonella Typhimurium Lacking fruR, ssrAB, or hfq as a Prophylactic Vaccine against Salmonella Lethal Infection
- Author
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Soyeon Park, Bogyo Jung, Eunsuk Kim, Hyunjin Yoon, and Tae-Wook Hahn
- Subjects
Salmonella vaccine ,Salmonella infection ,fruR ,cra ,Medicine - Abstract
Non-typhoidal Salmonella (NTS) is one of the primary causes of foodborne gastroenteritis; occasionally, it causes invasive infection in humans. Because of its broad host range, covering diverse livestock species, foods of animal origin pose a critical threat of NTS contamination. However, there is currently no licensed vaccine against NTS infection. FruR, also known as Cra (catabolite repressor/activator), was initially identified as the transcriptional repressor of the fructose (fru) operon, and then found to activate or repress the transcription of many different genes associated with carbon and energy metabolism. In view of its role as a global regulator, we constructed a live attenuated vaccine candidate, ΔfruR, and evaluated its prophylactic effect against NTS infection in mice. A Salmonella Typhimurium mutant strain lacking fruR was defective in survival inside macrophages and exhibited attenuated virulence in infected mice. Immunization with the ΔfruR mutant stimulated the production of antibodies, including the IgG, IgM, and IgG subclasses, and afforded a protection of 100% to mice against the challenge of lethal infection with a virulent Salmonella strain. The prophylactic effect obtained after ΔfruR immunization was also validated by the absence of signs of hepatosplenomegaly, as these mice had comparable liver and spleen weights in comparison with healthy mice. These results suggest that the ΔfruR mutant strain can be further exploited as a promising vaccine candidate against Salmonella lethal infection.
- Published
- 2022
- Full Text
- View/download PDF
31. TLR7 Stimulation With Imiquimod Induces Selective Autophagy and Controls Mycobacterium tuberculosis Growth in Mouse Macrophages
- Author
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Hyo-Ji Lee, Su-Jin Kang, Yunseo Woo, Tae-Wook Hahn, Hyun-Jeong Ko, and Yu-Jin Jung
- Subjects
autophagosome ,mycobactericidal activity ,imiquimod (IMQ) ,mitophagy ,Mycobacterium tuberculosis ,toll-like receptor 7 (TLR7) ,Microbiology ,QR1-502 - Abstract
Autophagy is a lysosomal self-digestion pathway that maintains internal homeostasis inside cells and critical process by which the innate immune system eliminates intracellular bacteria. In this study, we showed that stimulation of toll-like receptor 7 (TLR7) with imiquimod (IMQ) triggered autophagic cell death in macrophages by enhancing the generation of reactive oxygen species (ROS) via the p38- or MEK/ERK1/2-mediated signaling pathway in the early phase. IMQ significantly increased mitochondrial ROS and targeted autophagosomes to the mitochondria. Stimulation of TLR7 with IMQ enhanced the expression of BNIP3, which was localized to mitochondria and interacted with beclin-1, leading to mitophagy. In addition, IMQ substantially induced NO production through the GSK-3β-mediated signaling pathway, which led to autophagy in the late stage. We further examined whether the induction of autophagy by IMQ effectively eliminated intracellular microbes. Macrophages were infected with a virulent Mycobacterium tuberculosis (Mtb) strain, H37Rv, and then treated with IMQ. IMQ suppressed intracellular Mtb growth by inducing autophagy in a dose-dependent manner and increased NO production. Inhibition of autophagy using 3-methyladenine (3-MA) prevented autophagosome formation and control of intracellular Mtb growth in macrophages. These findings revealed a novel mechanism by which IMQ induces selective autophagy to promote intracellular killing machinery against Mtb infection in macrophages.
- Published
- 2020
- Full Text
- View/download PDF
32. Salmonella Typhimurium Lacking YjeK as a Candidate Live Attenuated Vaccine Against Invasive Salmonella Infection
- Author
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Soyeon Park, Bogyo Jung, Eunsuk Kim, Seong-Tshool Hong, Hyunjin Yoon, and Tae-Wook Hahn
- Subjects
Salmonella Typhimurium ,live attenuated vaccine ,YjeK ,elongation factor P ,non-typhoidal Salmonella ,immune protection ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Non-typhoidal Salmonella (NTS) causes gastrointestinal infection, which is commonly self-limiting in healthy humans but may lead to invasive infection at extraintestinal sites, leading to bacteremia and focal systemic infections in the immunocompromised. However, a prophylactic vaccine against invasive NTS has not yet been developed. In this work, we explored the potential of a ΔyjeK mutant strain as a live attenuated vaccine against invasive NTS infection. YjeK in combination with YjeA is required for the post-translational modification of elongation factor P (EF-P), which is critical for bacterial protein synthesis. Therefore, malfunction of YjeK and YjeA-mediated EF-P activation might extensively influence protein expression during Salmonella infection. Salmonella lacking YjeK showed substantial alterations in bacterial motility, antibiotics resistance, and virulence. Interestingly, deletion of the yjeK gene increased the expression levels of Salmonella pathogenicity island (SPI)-1 genes but decreased the transcription levels of SPI-2 genes, thereby influencing bacterial invasion and survival abilities in contact with host cells. In a mouse model, the ΔyjeK mutant strain alleviated the levels of splenomegaly and bacterial burdens in the spleen and liver in comparison with the wild-type strain. However, mice immunized with the ΔyjeK mutant displayed increased Th1- and Th2-mediated immune responses at 28 days post-infection, promoting cytokines and antibodies production. Notably, the Th2-associated antibody response was highly induced by administration of the ΔyjeK mutant strain. Consequently, vaccination with the ΔyjeK mutant strain protected 100% of the mice against challenge with lethal invasive Salmonella and significantly relieved bacterial burdens in the organs. Collectively, these results suggest that the ΔyjeK mutant strain can be exploited as a promising live attenuated NTS vaccine.
- Published
- 2020
- Full Text
- View/download PDF
33. Formation and Maturation of the Phagosome: A Key Mechanism in Innate Immunity against Intracellular Bacterial Infection
- Author
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Hyo-Ji Lee, Yunseo Woo, Tae-Wook Hahn, Young Mee Jung, and Yu-Jin Jung
- Subjects
phagocytosis ,phagosome maturation ,pathogen ,lysosome ,bacterial infection ,innate immunity ,Biology (General) ,QH301-705.5 - Abstract
Phagocytosis is an essential mechanism in innate immune defense, and in maintaining homeostasis to eliminate apoptotic cells or microbes, such as Mycobacterium tuberculosis, Salmonella enterica, Streptococcus pyogenes and Legionella pneumophila. After internalizing microbial pathogens via phagocytosis, phagosomes undergo a series of ‘maturation’ steps, to form an increasingly acidified compartment and subsequently fuse with the lysosome to develop into phagolysosomes and effectively eliminate the invading pathogens. Through this mechanism, phagocytes, including macrophages, neutrophils and dendritic cells, are involved in the processing of microbial pathogens and antigen presentation to T cells to initiate adaptive immune responses. Therefore, phagocytosis plays a role in the bridge between innate and adaptive immunity. However, intracellular bacteria have evolved diverse strategies to survive and replicate within hosts. In this review, we describe the sequential stages in the phagocytosis process. We also discuss the immune evasion strategies used by pathogens to regulate phagosome maturation during intracellular bacterial infection, and indicate that these might be used for the development of potential therapeutic strategies for infectious diseases.
- Published
- 2020
- Full Text
- View/download PDF
34. Carbopol-Incorporated Thermoreversible Gel for Intranasal Drug Delivery
- Author
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Prabagar Balakrishnan, Eun-Kyoung Park, Chung-Kil Song, Hyun-Jeong Ko, Tae-Wook Hahn, Ki-Won Song, and Hyun-Jong Cho
- Subjects
fexofenadine hydrochloride ,nasal delivery ,thermoreversibility ,poloxamer ,carbopol ,bioavailability ,Organic chemistry ,QD241-441 - Abstract
The present study describes the preparation and evaluation of a poloxamer 407 (P407)-based thermoreversible gel using Carbopol 934P (C934P) as a mucoadhesive polymer and hydroxypropyl-β-cyclodextrin (HP-β-CD) for enhancing the aqueous solubility and intranasal absorption of fexofenadine hydrochloride (FXD HCl). The prepared gels were characterized by gelation temperature, viscoelasticity, and drug release profile. Thermoreversibility of P407/C934P gel was demonstrated by rheological studies. The incorporation of carbopol into P407 gel also reduced the amounts of drug released from the gel formulations (p < 0.05). In vivo pharmacokinetic results of the prepared gel formulations in rabbits (at 0.5 mg/kg dose) showed that the relative bioavailability of drug from P407/C934P gel was 11.3 and 2.7-fold higher than those of drug solution and P407 gel group, respectively. These findings suggested that developed thermoreversible gels could be used as promising dosage forms to improve intranasal drug absorption.
- Published
- 2015
- Full Text
- View/download PDF
35. Modification of the fast fourier transform-based method by signal mirroring for accuracy quantification of thermal-hydraulic system code
- Author
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Tae Wook Ha, Jae Jun Jeong, and Ki Yong Choi
- Subjects
Cut-Off Frequency ,Fast Fourier Transform-Based Method by Signal Mirroring ,Frequency-Dependent Evaluation ,Nuclear engineering. Atomic power ,TK9001-9401 - Abstract
A thermal–hydraulic system code is an essential tool for the design and safety analysis of a nuclear power plant, and its accuracy quantification is very important for the code assessment and applications. The fast Fourier transform-based method (FFTBM) by signal mirroring (FFTBM-SM) has been used to quantify the accuracy of a system code by using a comparison of the experimental data and the calculated results. The method is an improved version of the FFTBM, and it is known that the FFTBM-SM judges the code accuracy in a more consistent and unbiased way. However, in some applications, unrealistic results have been obtained. In this study, it was found that accuracy quantification by FFTBM-SM is dependent on the frequency spectrum of the fast Fourier transform of experimental and error signals. The primary objective of this study is to reduce the frequency dependency of FFTBM-SM evaluation. For this, it was proposed to reduce the cut off frequency, which was introduced to cut off spurious contributions, in FFTBM-SM. A method to determine an appropriate cut off frequency was also proposed. The FFTBM-SM with the modified cut off frequency showed a significant improvement of the accuracy quantification.
- Published
- 2017
- Full Text
- View/download PDF
36. Removal of Ammonia by Biofilters: A Study with Flow-Modified System and Kinetics.
- Author
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Jeong Hak Choi, R., Young Hun Kim, R., Duk Jong Joo, R., Sang June Choi, Tae Wook Ha, R., Dal Hoon Lee, R., In Ho Park, R., and Yun Seok Jeong, R.
- Subjects
- *
AMMONIA , *AIR pollution , *GAS flow , *POLLUTION control equipment , *DYNAMICS , *ENVIRONMENTAL engineering - Abstract
Investigates the characteristics of ammonia removal by two types of biofilter, a standard biofilter with vertical gas flow and a modified biofilter with horizontal gas flow. Organic materials used as a biofilter media based on the small-scale column test for media selection; Removal efficiency of the two types of biofilter systems; Kinetic analysis of the biological removal of ammonia in each biofilter system.
- Published
- 2003
- Full Text
- View/download PDF
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